INTRODUCTION
[0001] Various aspects described herein generally relate to wireless communication systems,
and more specifically to device-to-device communications over sidelink.
[0002] Wireless communication systems have developed through various generations, including
a first-generation analog wireless phone service (1G), a second-generation (2G) digital
wireless phone service (including interim 2.5G networks), a thirdgeneration (3G) high
speed data, Internet-capable wireless service and a fourthgeneration (4G) service
(e.g., LTE or WiMax). There are presently many different types of wireless communication
systems in use, including cellular and personal communications service (PCS) systems.
Examples of known cellular systems include the cellular analog advanced mobile phone
system (AMPS), and digital cellular systems based on code division multiple access
(CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA),
the global system for mobile access (GSM) variation of TDMA, etc.
[0003] A fifth generation (5G) wireless standard, referred to as New Radio (NR), enables
higher data transfer speeds, greater numbers of connections, and better coverage,
among other improvements. The NR standard, according to the Next Generation Mobile
Networks Alliance, is designed to provide data rates of several tens of megabits per
second to each of tens of thousands of users, with 1 gigabit per second to tens of
workers on an office floor. Several hundreds of thousands of simultaneous connections
should be supported in order to support large wireless sensor deployments. Consequently,
the spectral efficiency of NR mobile communications should be significantly enhanced
compared to the current 4G standard. Furthermore, signaling efficiencies should be
enhanced and latency should be substantially reduced compared to current standards.
[0004] Leveraging the increased data rates and decreased latency of 5G, among other things,
vehicle-to-everything (V2X) communication technologies are being implemented to support
autonomous driving applications, such as wireless communications between vehicles,
between vehicles and the roadside infrastructure, between vehicles and pedestrians,
etc.
SUMMARY
[0006] The invention is defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings are presented to aid in the description of examples of
one or more aspects of the disclosed subject matter and are provided solely for illustration
of the examples and not limitation thereof:
FIG. 1 illustrates an exemplary wireless communications system in accordance with
one or more aspects of the disclosure.
FIGS. 2A and 2B illustrate example wireless network structures, according to various
aspects.
FIG. 3 illustrates an example of a wireless communications system that supports unicast
sidelink establishment in accordance with aspects of the disclosure.
FIG. 4 is a block diagram illustrating various components of an exemplary UE according
to at least one aspect of the disclosure.
FIG. 5 illustrates an exemplary flow between an initiator device and a target device,
according to aspects of the disclosure.
FIGS. 6 to 9 illustrate exemplary flows for wireless communication, according to aspects
of the disclosure.
FIGS. 10 to 15 illustrate exemplary apparatuses for wireless communication, according
to aspects of the disclosure.
DETAILED DESCRIPTION
[0008] Disclosed are techniques for establishing a device-to-device unicast sidelink between
an initiator device and a target device in a millimeter wave (mmW) frequency band.
In an aspect, the devices may obtain connection setup parameters for the mmW unicast
sidelink from a previously established non-mmW link between the devices or between
at least one of the devices and a base station. The connection setup parameters may
include the locations of the devices, a requested quality of service (QoS) for the
mmW unicast sidelink, the number of transmit beams used by the initiator device for
the mmW unicast sidelink, periodicity of the transmit beams, and the beam response
and/or physical random access channel (PRACH) configuration for the transmit beams.
By using the previously established non-mmW link to obtain the connection setup parameters
for the mmW unicast sidelink, beam pair link (BPL) acquisition and resource utilization
are sped up in the for the mmW unicast sidelink. Once the mmW unicast sidelink is
established from the initiator device to the target device, the initiator device can
transmit data to the target device over the mmW unicast link. In addition, if desired,
the target device can transmit data to the initiator device with support of, for example,
reflective QoS.
[0009] These and other aspects of the subject matter are provided in the following description
and related drawings directed to specific examples of the disclosed subject matter.
Alternates may be devised without departing from the scope of the disclosed subject
matter. Additionally, well-known elements will not be described in detail or will
be omitted so as not to obscure the relevant details of the disclosure.
[0010] The words "exemplary" and/or "example" are used herein to mean "serving as an example,
instance, or illustration." Any aspect described herein as "exemplary" and/or "example"
is not necessarily to be construed as preferred or advantageous over other aspects.
Likewise, the term "aspects of the disclosure" does not require that all aspects of
the disclosure include the discussed feature, advantage or mode of operation.
[0011] Those of skill in the art will appreciate that the information and signals described
below may be represented using any of a variety of different technologies and techniques.
For example, data, instructions, commands, information, signals, bits, symbols, and
chips that may be referenced throughout the description below may be represented by
voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields
or particles, or any combination thereof, depending in part on the particular application,
in part on the desired design, in part on the corresponding technology, etc.
[0012] Further, many aspects are described in terms of sequences of actions to be performed
by, for example, elements of a computing device. It will be recognized that various
actions described herein can be performed by specific circuits (e.g., application
specific integrated circuits (ASICs)), by program instructions being executed by one
or more processors, or by a combination of both. Additionally, the sequence(s) of
actions described herein can be considered to be embodied entirely within any form
of nontransitory computer-readable storage medium having stored therein a corresponding
set of computer instructions that, upon execution, would cause or instruct an associated
processor of a device to perform the functionality described herein. Thus, the various
aspects of the disclosure may be embodied in a number of different forms, all of which
have been contemplated to be within the scope of the claimed subject matter. In addition,
for each of the aspects described herein, the corresponding form of any such aspects
may be described herein as, for example, "logic configured to" perform the described
action.
[0013] As used herein, the terms "user equipment" (UE), "vehicle UE" (V-UE), "pedestrian
UE" (P-UE), and "base station" are not intended to be specific or otherwise limited
to any particular radio access technology (RAT), unless otherwise noted. In general,
a UE may be any wireless communication device (e.g., vehicle on-board computer, vehicle
navigation device, mobile phone, router, tablet computer, laptop computer, tracking
device, wearable (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality
(VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet
of Things (IoT) device, etc.) used by a user to communicate over a wireless communications
network. A UE may be mobile or may (e.g., at certain times) be stationary, and may
communicate with a radio access network (RAN). As used herein, the term "UE" may be
referred to interchangeably as an "access terminal" or "AT," a "client device," a
"wireless device," a "subscriber device," a "subscriber terminal," a "subscriber station,"
a "user terminal" or UT, a "mobile terminal," a "mobile station," or variations thereof.
[0014] A V-UE is a type of UE and may be any in-vehicle wireless communication device, such
as a navigation system, a warning system, a heads-up display (HUD), an on-board computer,
etc. Alternatively, a V-UE may be a portable wireless communication device (e.g.,
a cell phone, tablet computer, etc.) that is carried by the driver of the vehicle
or a passenger in the vehicle. The term "V-UE" may refer to the in-vehicle wireless
communication device or the vehicle itself, depending on the context. A P-UE is a
type of UE and may be a portable wireless communication device that is carried by
a pedestrian (i.e., a user that is not driving or riding in a vehicle). Generally,
UEs can communicate with a core network via a RAN, and through the core network the
UEs can be connected with external networks such as the Internet and with other UEs.
Of course, other mechanisms of connecting to the core network and/or the Internet
are also possible for the UEs, such as over wired access networks, wireless local
area network (WLAN) networks (e.g., based on IEEE 802.11, etc.) and so on.
[0015] A base station may operate according to one of several RATs in communication with
UEs depending on the network in which it is deployed, and may be alternatively referred
to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a New
Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. In addition, in some
systems a base station may provide purely edge node signaling functions while in other
systems it may provide additional control and/or network management functions. A communication
link through which UEs can send signals to a base station is called an uplink (UL)
channel (e.g., a reverse traffic channel, a reverse control channel, an access channel,
etc.). A communication link through which the base station can send signals to UEs
is called a downlink (DL) or forward link channel (e.g., a paging channel, a control
channel, a broadcast channel, a forward traffic channel, etc.). As used herein the
term traffic channel (TCH) can refer to either an UL / reverse or DL / forward traffic
channel.
[0016] The term "base station" may refer to a single physical transmission-reception point
(TRP) or to multiple physical TRPs that may or may not be co-located. For example,
where the term "base station" refers to a single physical TRP, the physical TRP may
be an antenna of the base station corresponding to a cell of the base station. Where
the term "base station" refers to multiple co-located physical TRPs, the physical
TRPs may be an array of antennas (e.g., as in a multiple-input multiple-output (MIMO)
system or where the base station employs beamforming) of the base station. Where the
term "base station" refers to multiple non-co-located physical TRPs, the physical
TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas
connected to a common source via a transport medium) or a remote radio head (RRH)
(a remote base station connected to a serving base station). Alternatively, the non-co-located
physical TRPs may be the serving base station receiving the measurement report from
the UE and a neighbor base station whose reference RF signals the UE is measuring.
Because a TRP is the point from which a base station transmits and receives wireless
signals, as used herein, references to transmission from or reception at a base station
are to be understood as referring to a particular TRP of the base station.
[0017] An "RF signal" comprises an electromagnetic wave of a given frequency that transports
information through the space between a transmitter and a receiver. As used herein,
a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver.
However, the receiver may receive multiple "RF signals" corresponding to each transmitted
RF signal due to the propagation characteristics of RF signals through multipath channels.
The same transmitted RF signal on different paths between the transmitter and receiver
may be referred to as a "multipath" RF signal.
[0018] According to various aspects,
FIG. 1 illustrates an exemplary wireless communications system 100. The wireless communications
system 100 (which may also be referred to as a wireless wide area network (WWAN))
may include various base stations 102 (labelled "BS") and various UEs 104. The base
stations 102 may include macro cell base stations (high power cellular base stations)
and/or small cell base stations (low power cellular base stations). In an aspect,
the macro cell base stations 102 may include eNBs where the wireless communications
system 100 corresponds to an LTE network, or gNBs where the wireless communications
system 100 corresponds to a NR network, or a combination of both, and the small cell
base stations may include femtocells, picocells, microcells, etc.
[0019] The base stations 102 may collectively form a RAN and interface with a core network
174 (e.g., an evolved packet core (EPC) or next generation core (NGC)) through backhaul
links 122, and through the core network 174 to one or more location servers 172. In
addition to other functions, the base stations 102 may perform functions that relate
to one or more of transferring user data, radio channel ciphering and deciphering,
integrity protection, header compression, mobility control functions (e.g., handover,
dual connectivity), inter-cell interference coordination, connection setup and release,
load balancing, distribution for non-access stratum (NAS) messages, NAS node selection,
synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber
and equipment trace, RAN information management (RIM), paging, positioning, and delivery
of warning messages. The base stations 102 may communicate with each other directly
or indirectly (e.g., through the EPC / NGC) over backhaul links 134, which may be
wired or wireless.
[0020] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base
stations 102 may provide communication coverage for a respective geographic coverage
area 110. In an aspect, one or more cells may be supported by a base station 102 in
each geographic coverage area 110. A "cell" is a logical communication entity used
for communication with a base station (e.g., over some frequency resource, referred
to as a carrier frequency, component carrier, carrier, band, or the like), and may
be associated with an identifier (e.g., a physical cell identifier (PCI), an enhanced
cell identifier (ECI), a virtual cell identifier (VCI), etc.) for distinguishing cells
operating via the same or a different carrier frequency. In some cases, different
cells may be configured according to different protocol types (e.g., machine-type
communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or
others) that may provide access for different types of UEs. Because a cell is supported
by a specific base station, the term "cell" may refer to either or both the logical
communication entity and the base station that supports it, depending on the context.
In some cases, the term "cell" may also refer to a geographic coverage area of a base
station (e.g., a sector), insofar as a carrier frequency can be detected and used
for communication within some portion of geographic coverage areas 110.
[0021] While neighboring macro cell base station 102 geographic coverage areas 110 may partially
overlap (e.g., in a handover region), some of the geographic coverage areas 110 may
be substantially overlapped by a larger geographic coverage area 110. For example,
a small cell base station 102' (labelled "SC" for "small cell") may have a coverage
area 110' that substantially overlaps with the geographic coverage area 110 of one
or more macro cell base stations 102. A network that includes both small cell and
macro cell base stations may be known as a heterogeneous network. A heterogeneous
network may also include home eNBs (HeNBs), which may provide service to a restricted
group known as a closed subscriber group (CSG).
[0022] The communication links 120 between the base stations 102 and the UEs 104 may include
UL (also referred to as reverse link) transmissions from a UE 104 to a base station
102 and/or downlink (DL) (also referred to as forward link) transmissions from a base
station 102 to a UE 104. The communication links 120 may use MIMO antenna technology,
including spatial multiplexing, beamforming, and/or transmit diversity. The communication
links 120 may be through one or more carrier frequencies. Allocation of carriers may
be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated
for DL than for UL).
[0023] The wireless communications system 100 may further include a wireless local area
network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152
via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When
communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and/or the WLAN
AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure
prior to communicating in order to determine whether the channel is available.
[0024] The small cell base station 102' may operate in a licensed and/or an unlicensed frequency
spectrum. When operating in an unlicensed frequency spectrum, the small cell base
station 102' may employ LTE or NR technology and use the same 5 GHz unlicensed frequency
spectrum as used by the WLAN AP 150. The small cell base station 102', employing LTE
/ 5G in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity
of the access network. NR in unlicensed spectrum may be referred to as NR-U. LTE in
an unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA),
or MulteFire.
[0025] The wireless communications system 100 may further include a millimeter wave (mmW)
base station 180 that may operate in mmW frequencies and/or near mmW frequencies in
communication with a UE 182. Extremely high frequency (EHF) is part of the RF in the
electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between
1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a
millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength
of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and
30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW
radio frequency band have high path loss and a relatively short range. The mmW base
station 180 and the UE 182 may utilize beamforming (transmit and/or receive) over
a mmW communication link 184 to compensate for the extremely high path loss and short
range. Further, it will be appreciated that in alternative configurations, one or
more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly,
it will be appreciated that the foregoing illustrations are merely examples and should
not be construed to limit the various aspects disclosed herein.
[0026] Transmit beamforming is a technique for focusing an RF signal in a specific direction.
Traditionally, when a network node (e.g., a base station) broadcasts an RF signal,
it broadcasts the signal in all directions (omni-directionally). With transmit beamforming,
the network node determines where a given target device (e.g., a UE) is located (relative
to the transmitting network node) and projects a stronger downlink RF signal in that
specific direction, thereby providing a faster (in terms of data rate) and stronger
RF signal for the receiving device(s). To change the directionality of the RF signal
when transmitting, a network node can control the phase and relative amplitude of
the RF signal at each of the one or more transmitters that are broadcasting the RF
signal. For example, a network node may use an array of antennas (referred to as a
"phased array" or an "antenna array") that creates a beam of RF waves that can be
"steered" to point in different directions, without actually moving the antennas.
Specifically, the RF current from the transmitter is fed to the individual antennas
with the correct phase relationship so that the radio waves from the separate antennas
add together to increase the radiation in a desired direction, while cancelling to
suppress radiation in undesired directions.
[0027] Transmit beams may be quasi-collocated, meaning that they appear to the receiver
(e.g., a UE) as having the same parameters, regardless of whether or not the transmitting
antennas of the network node themselves are physically collocated. In NR, there are
four types of quasi-collocation (QCL) relations. Specifically, a QCL relation of a
given type means that certain parameters about a second reference RF signal on a second
beam can be derived from information about a source reference RF signal on a source
beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use
the source reference RF signal to estimate the Doppler shift, Doppler spread, average
delay, and delay spread of a second reference RF signal transmitted on the same channel.
If the source reference RF signal is QCL Type B, the receiver can use the source reference
RF signal to estimate the Doppler shift and Doppler spread of a second reference RF
signal transmitted on the same channel. If the source reference RF signal is QCL Type
C, the receiver can use the source reference RF signal to estimate the Doppler shift
and average delay of a second reference RF signal transmitted on the same channel.
If the source reference RF signal is QCL Type D, the receiver can use the source reference
RF signal to estimate the spatial receive parameter of a second reference RF signal
transmitted on the same channel.
[0028] In receive beamforming, the receiver uses a receive beam to amplify RF signals detected
on a given channel. For example, the receiver can increase the gain setting and/or
adjust the phase setting of an array of antennas in a particular direction to amplify
(e.g., to increase the gain level of) the RF signals received from that direction.
Thus, when a receiver is said to beamform in a certain direction, it means the beam
gain in that direction is high relative to the beam gain along other directions, or
the beam gain in that direction is the highest compared to the beam gain in that direction
of all other receive beams available to the receiver. This results in a stronger received
signal strength (e.g., reference signal received power (RSRP), reference signal received
quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of the RF signals
received from that direction.
[0029] Transmit and receive beams may be spatially related. A spatial relation means that
parameters for a second beam (e.g., a transmit or receive beam) for a second reference
signal can be derived from information about a first beam (e.g., a receive beam or
a transmit beam) for a first reference signal. For example, a UE may use a particular
receive beam to receive a reference downlink reference signal (e.g., synchronization
signal block (SSB)) from a base station. The UE can then form a transmit beam for
sending an uplink reference signal (e.g., sounding reference signal (SRS)) to that
base station based on the parameters of the receive beam.
[0030] Note that a "downlink" beam may be either a transmit beam or a receive beam, depending
on the entity forming it. For example, if a base station is forming the downlink beam
to transmit a reference signal to a UE, the downlink beam is a transmit beam. If the
UE is forming the downlink beam, however, it is a receive beam to receive the downlink
reference signal. Similarly, an "uplink" beam may be either a transmit beam or a receive
beam, depending on the entity forming it. For example, if a base station is forming
the uplink beam, it is an uplink receive beam, and if a LTE is forming the uplink
beam, it is an uplink transmit beam.
[0031] In 5G, the frequency spectrum in which wireless nodes (e.g., base stations 102/180,
UEs 104/182) operate is divided into multiple frequency ranges, FR1 (from 450 to 6000
MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and
FR2). In a multi-carrier system, such as 5G, one of the carrier frequencies is referred
to as the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell,"
and the remaining carrier frequencies are referred to as "secondary carriers" or "secondary
serving cells" or "SCells." In carrier aggregation, the anchor carrier is the carrier
operating on the primary frequency (e.g., FR1) utilized by a UE 104/182 and the cell
in which the UE 104/182 either performs the initial radio resource control (RRC) connection
establishment procedure or initiates the RRC connection re-establishment procedure.
The primary carrier carries all common and UE-specific control channels, and may be
a carrier in a licensed frequency (however, this is not always the case). A secondary
carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured
once the RRC connection is established between the UE 104 and the anchor carrier and
that may be used to provide additional radio resources. In some cases, the secondary
carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain
only necessary signaling information and signals, for example, those that are UE-specific
may not be present in the secondary carrier, since both primary uplink and downlink
carriers are typically UE-specific. This means that different UEs 104/182 in a cell
may have different downlink primary carriers. The same is true for the uplink primary
carriers. The network is able to change the primary carrier of any UE 104/182 at any
time. This is done, for example, to balance the load on different carriers. Because
a "serving cell" (whether a PCell or an SCell) corresponds to a carrier frequency
/ component carrier over which some base station is communicating, the term "cell,"
"serving cell," "component carrier," "carrier frequency," and the like can be used
interchangeably.
[0032] For example, still referring to FIG. 1, one of the frequencies utilized by the macro
cell base stations 102 may be an anchor carrier (or "PCell") and other frequencies
utilized by the macro cell base stations 102 and/or the mmW base station 180 may be
secondary carriers ("SCells"). The simultaneous transmission and/or reception of multiple
carriers enables the UE 104/182 to significantly increase its data transmission and/or
reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system
would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz), compared
to that attained by a single 20 MHz carrier.
[0033] The wireless communications system 100 may further include one or more UEs, such
as UE 190, that connects indirectly to one or more communication networks via one
or more device-to-device (D2D) peer-to-peer (P2P) links. In the example of FIG. 1,
UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base
stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity)
and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which
UE 190 may indirectly obtain WLAN-based Internet connectivity). In an example, the
D2D P2P links 192 and 194 may be supported with any well-known D2D RAT, such as LTE
Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth
®, and so on.
[0034] Leveraging the increased data rates and decreased latency of NR, among other things,
vehicle-to-everything (V2X) communication technologies are being implemented to support
intelligent transportation systems (ITS) applications, such as wireless communications
between vehicles (vehicle-to-vehicle (V2V)), between vehicles and the roadside infrastructure
(vehicle-to-infrastructure (V2I)), and between vehicles and pedestrians (vehicle-to-pedestrian
(V2P)). The goal is for vehicles to be able to sense the environment around them and
communicate that information to other vehicles, infrastructure, and personal mobile
devices. Such vehicle communication will enable safety, mobility, and environmental
advancements that current technologies are unable to provide. Once fully implemented,
the technology is expected to reduce unimpaired vehicle crashes by 80%.
[0035] Still referring to FIG. 1, the wireless communications system 100 may include multiple
V-UEs 160 that may communicate with base stations 102 over communication links 120
(e.g., using the Uu interface). V-UEs 160 may also communicate directly with each
other over a wireless unicast sidelink 162, with a roadside access point 164 over
a sidelink 166, or with UEs 104 over a sidelink 168 using P2P/D2D protocols (e.g.,
"PC5," an LTE V2X D2D interface) or ProSe direct communications. Sidelink communication
may be used for D2D media-sharing, V2V communication, V2X communication (e.g., cellular
V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue
applications, etc. One or more of a group of V-UEs 160 utilizing D2D communications
may be within the geographic coverage area 110 of a base station 102. Other V-UEs
160 in such a group may be outside the geographic coverage area 110 of a base station
102 or be otherwise unable to receive transmissions from a base station 102. In some
cases, groups of V-UEs 160 communicating via D2D communications may utilize a one-to-many
(1:M) system in which each V-UE 160 transmits to every other V-UE 160 in the group.
In some cases, a base station 102 facilitates the scheduling of resources for D2D
communications. In other cases, D2D communications are carried out between V-UEs 160
without the involvement of a base station 102.
[0036] In an aspect, the V-UEs 160, and any other UE illustrated in FIG. 1, may have a sidelink
manager 170. The sidelink manager 170 may be a hardware, software, or firmware component
that, when executed, causes the V-UE 160 to perform the operations described herein.
For example, the sidelink manager 170 may be a software module stored in a memory
of the V-UE 160 and executable by a processor of the V-UE 160. As another example,
the sidelink manager 170 may be a hardware circuit (e.g., an ASIC, a field programmable
gate array (FPGA), etc.) within the V-UE 160. Note that although only one UE (V-UE
160) is illustrated as including a sidelink manager 170, any of the illustrated UEs
may include a sidelink manager 170.
[0037] In an aspect, the sidelinks 162, 166, 168 may operate over a communication medium
of interest, which may be shared with other communications between other vehicles
and/or infrastructure access points, as well as other RATs. A "medium" may be composed
of one or more frequency, time, and/or space communication resources (e.g., encompassing
one or more channels across one or more carriers) associated with communication between
one or more transmitter / receiver pairs.
[0038] In an aspect, the sidelinks 162, 166, 168 may be cV2X links. A first generation of
cV2X has been standardized in LTE, and the next generation is expected to be defined
in NR. cV2X is a cellular technology that also enables device-to-device communications.
In the U.S. and Europe, cV2X is expected to operate in the licensed ITS band in sub-6GHz.
Other bands may be allocated in other countries. Thus, as a particular example, the
medium of interest utilized by sidelinks 162, 166, 168 may correspond to at least
a portion of the licensed ITS frequency band of sub-6GHz. However, the present disclosure
is not limited to this frequency band or cellular technology.
[0039] In an aspect, the sidelinks 162, 166, 168 may be dedicated short-range communications
(DSRC) links. DSRC is a one-way or two-way short-range to medium-range wireless communication
protocol that uses the wireless access for vehicular environments (WAVE) protocol,
also known as IEEE 802.11p, for V2V, V2I, and V2P communications. IEEE 802.11p is
an approved amendment to the IEEE 802.11 standard and operates in the licensed ITS
band of 5.9 GHz (5.85-5.925 GHz) in the U.S. In Europe, IEEE 802.11p operates in the
ITS G5A band (5.875 - 5.905 MHz). Other bands may be allocated in other countries.
The V2V communications briefly described above occur on the Safety Channel, which
in the U.S. is typically a 10 MHz channel that is dedicated to the purpose of safety.
The remainder of the DSRC band (the total bandwidth is 75 MHz) is intended for other
services of interest to drivers, such as road rules, tolling, parking automation,
etc. Thus, as a particular example, the mediums of interest utilized by sidelinks
162, 166, 168 may correspond to at least a portion of the licensed ITS frequency band
of 5.9 GHz.
[0040] Alternatively, the medium of interest may correspond to at least a portion of an
unlicensed frequency band shared among various RATs. Although different licensed frequency
bands have been reserved for certain communication systems (e.g., by a government
entity such as the Federal Communications Commission (FCC) in the United States),
these systems, in particular those employing small cell access points, have recently
extended operation into unlicensed frequency bands such as the Unlicensed National
Information Infrastructure (U-NII) band used by wireless local area network (WLAN)
technologies, most notably IEEE 802.11x WLAN technologies generally referred to as
"Wi-Fi." Example systems of this type include different variants of CDMA systems,
TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single-carrier FDMA (SC-FDMA)
systems, and so on.
[0041] Communications between the V-UEs 160 are referred to as V2V communications, communications
between the V-UEs 160 and the one or more roadside access points 164 are referred
to as V2I communications, and communications between the V-UEs 160 and one or more
UEs 104 (where the UEs 104 are P-UEs) are referred to as V2P communications. The V2V
communications between V-UEs 160 may include, for example, information about the position,
speed, acceleration, heading, and other vehicle data of the V-UEs 160. The V2I information
received at a V-UE 160 from the one or more roadside access points 164 may include,
for example, road rules, parking automation information, etc. The V2P communications
between a V-UE 160 and a UE 104 may include information about, for example, the position,
speed, acceleration, and heading of the V-UE 160 and the position, speed (e.g., where
the UE 104 is carried by a user on a bicycle), and heading of the UE 104.
[0042] Note that although FIG. 1 only illustrates two of the UEs as V-UEs (V-UEs 160), any
of the illustrated UEs (e.g., UEs 104, 152, 182, 190) may be V-UEs. In addition, although
only UE 182 was described as being capable of beam forming, any of the illustrated
UEs, including V-UEs 160, may be capable of beam forming. Where V-UEs 160 are capable
of beam forming, they may beam form towards each other (i.e., towards other V-UEs
160), towards roadside access points 164, towards other UEs (e.g., UEs 104, 152, 182,
190), etc. Thus, in some cases, V-UEs 160 may utilize beamforming over sidelinks 162,
166, and 168.
[0043] According to various aspects,
FIG. 2A illustrates an exemplary wireless network structure 200. For example, an NGC 210
(also referred to as a "5GC") can be viewed functionally as control plane functions
(C-plane) 214 (e.g., UE registration, authentication, network access, gateway selection,
etc.) and user plane functions (U-plane) 212 (e.g., UE gateway function, access to
data networks, IP routing, etc.), which operate cooperatively to form the core network.
User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect the
gNB 222 to the NGC 210 and specifically to the user plane functions 212 and control
plane functions 214, respectively. In an additional configuration, an eNB 224 may
also be connected to the NGC 210 via NG-C 215 to the control plane functions 214 and
NG-U 213 to user plane functions 212. Further, eNB 224 may directly communicate with
gNB 222 via a backhaul connection 223. In some configurations, the New RAN 220 may
only have one or more gNBs 222, while other configurations include one or more of
both eNBs 224 and gNBs 222. Either gNB 222 or eNB 224 may communicate with UEs 204
(e.g., any of the UEs depicted in FIG. 1). In an aspect, two UEs 204 may communicate
with each other over a wireless unicast sidelink 242, which may correspond to wireless
unicast sidelink 162 in FIG. 1.
[0044] Another optional aspect may include location server 230, which may be in communication
with the NGC 210 to provide location assistance for UEs 204. The location server 230
can be implemented as a plurality of separate servers (e.g., physically separate servers,
different software modules on a single server, different software modules spread across
multiple physical servers, etc.), or alternately may each correspond to a single server.
The location server 230 can be configured to support one or more location services
for UEs 204 that can connect to the location server 230 via the core network, NGC
210, and/or via the Internet (not illustrated). Further, the location server 230 may
be integrated into a component of the core network, or alternatively may be external
to the core network.
[0045] According to various aspects,
FIG. 2B illustrates another exemplary wireless network structure 250. For example, an NGC
260 (also referred to as a "5GC") can be viewed functionally as control plane functions,
provided by an access and mobility management function (AMF) / user plane function
(UPF) 264, and user plane functions, provided by a session management function (SMF)
262, which operate cooperatively to form the core network (i.e., NGC 260). User plane
interface 263 and control plane interface 265 connect the eNB 224 to the NGC 260 and
specifically to SMF 262 and AMF/UPF 264, respectively. In an additional configuration,
a gNB 222 may also be connected to the NGC 260 via control plane interface 265 to
AMF/UPF 264 and user plane interface 263 to SMF 262. Further, eNB 224 may directly
communicate with gNB 222 via the backhaul connection 223, with or without gNB direct
connectivity to the NGC 260. In some configurations, the New RAN 220 may only have
one or more gNBs 222, while other configurations include one or more of both eNBs
224 and gNBs 222. Either gNB 222 or eNB 224 may communicate with UEs 204 (e.g., any
of the UEs depicted in FIG. 1). The base stations of the New RAN 220 communicate with
the AMF-side of the AMF/UPF 264 over the N2 interface and the UPF-side of the AMF/UPF
264 over the N3 interface. In an aspect, two UEs 204 may communicate with each other
over a wireless unicast sidelink 242, which may correspond to wireless unicast sidelink
162 in FIG. 1.
[0046] The functions of the AMF include registration management, connection management,
reachability management, mobility management, lawful interception, transport for session
management (SM) messages between the UE 204 and the SMF 262, transparent proxy services
for routing SM messages, access authentication and access authorization, transport
for short message service (SMS) messages between the UE 204 and the short message
service function (SMSF) (not shown), and security anchor functionality (SEAF). The
AMF also interacts with the authentication server function (AUSF) (not shown) and
the UE 204, and receives the intermediate key that was established as a result of
the LTE 204 authentication process. In the case of authentication based on a UMTS
(universal mobile telecommunications system) subscriber identity module (USIM), the
AMF retrieves the security material from the AUSF. The functions of the AMF also include
security context management (SCM). The SCM receives a key from the SEAF that it uses
to derive access-network specific keys. The functionality of the AMF also includes
location services management for regulatory services, transport for location services
messages between the UE 204 and the location management function (LMF) 270, as well
as between the New RAN 220 and the LMF 270, evolved packet system (EPS) bearer identifier
allocation for interworking with the EPS, and UE 204 mobility event notification.
In addition, the AMF also supports functionalities for non-3GPP access networks.
[0047] Functions of the UPF include acting as an anchor point for intra-/inter-RAT mobility
(when applicable), acting as an external protocol data unit (PDU) session point of
interconnect to the data network (not shown), providing packet routing and forwarding,
packet inspection, user plane policy rule enforcement (e.g., gating, redirection,
traffic steering), lawful interception (user plane collection), traffic usage reporting,
quality of service (QoS) handling for the user plane (e.g., uplink/downlink rate enforcement,
reflective QoS marking in the downlink), uplink traffic verification (service data
flow (SDF) to QoS flow mapping), transport level packet marking in the uplink and
downlink, downlink packet buffering and downlink data notification triggering, and
sending and forwarding of one or more "end markers" to the source RAN node.
[0048] The functions of the SMF 262 include session management, UE Internet protocol (IP)
address allocation and management, selection and control of user plane functions,
configuration of traffic steering at the UPF to route traffic to the proper destination,
control of part of policy enforcement and QoS, and downlink data notification. The
interface over which the SMF 262 communicates with the AMF-side of the AMF/UPF 264
is referred to as the N11 interface.
[0049] Another optional aspect may include a LMF 270, which may be in communication with
the NGC 260 to provide location assistance for UEs 204. The LMF 270 can be implemented
as a plurality of separate servers (e.g., physically separate servers, different software
modules on a single server, different software modules spread across multiple physical
servers, etc.), or alternately may each correspond to a single server. The LMF 270
can be configured to support one or more location services for UEs 204 that can connect
to the LMF 270 via the core network, NGC 260, and/or via the Internet (not illustrated).
[0050] FIG. 3 illustrates an example of a wireless communications system 300 that supports unicast
sidelink establishment in accordance with aspects of the disclosure. In some examples,
wireless communications system 300 may implement aspects of wireless communications
systems 100, 200, and 250. Wireless communications system 300 may include a first
UE 302 and a second UE 304, which may be examples of any of the UEs described herein.
As a specific example, UEs 302 and 304 may correspond to V-UEs 160 in FIG. 1. In the
example of FIG. 3, the UE 302 may attempt to establish a unicast connection over a
sidelink with UE 304, which may be a V2X communication link between UE 302 and UE
304. Additionally or alternatively, the unicast connection over the sidelink may generally
be used for sidelink communications between any two UEs. Thus, the established sidelink
connection may correspond to sidelinks 162 and/or 168 in FIG. 1 and/or wireless unicast
sidelink 242 in FIGS. 2A and 2B. The sidelink connection may be established for signaling
in an omni-directional frequency range (e.g., FR1) as shown in the upper part of the
FIG. 3, and a mmW frequency range (e.g., FR2) for data transmission as shown in the
lower part of FIG. 3. In some cases, UE 302 may be referred to as an initiating UE
that initiates the unicast connection procedure, and UE 304 may be referred to as
a target UE that is targeted for the unicast connection procedure by the initiating
UE.
[0051] For establishing the unicast connection, access stratum (AS) (a functional layer
in the UMTS and LTE protocol stacks between the RAN and the UE that is responsible
for transporting data over wireless links and managing radio resources, also referred
to as "Layer 2" or "L2") parameters may be configured and negotiated between UE 302
and UE 304. For example, a transmission and reception capability matching may be negotiated
between UE 302 and UE 304. Each UE may have different capabilities (e.g., transmission
and reception capabilities, 64 quadrature amplitude modulation (QAM), transmission
diversity, carrier aggregation (CA) capabilities, supported communications frequency
band(s), etc.). In some cases, different services may be supported at the upper layers
of corresponding protocol stacks for UE 302 and UE 304. Additionally, a security association
may be established between UE 302 and UE 304 for the unicast connection. Unicast traffic
may benefit from security protection at a link level (e.g., integrity protection).
Security requirements may differ for different wireless communications systems. For
example, V2X and Uu systems may have different security requirements (e.g., Uu security
does not include confidentiality protection). Additionally, IP configurations (e.g.,
IP versions, addresses, etc.) may be negotiated for the unicast connection between
UE 302 and UE 304.
[0052] In some cases, UE 304 may create a service announcement (e.g., a service capability
message) to transmit over a cellular network (e.g., cV2X) to assist the unicast connection
establishment. Conventionally, UE 302 may identify and locate candidates for unicast
communications based on a basic service message (BSM) broadcasted unencrypted by nearby
UEs (e.g., UE 304). The BSM may include location information, security and identity
information, and vehicle information (e.g., speed, maneuver, size, etc.) for the corresponding
UE. However, for different wireless communications systems (e.g., D2D or V2X communications),
a discovery channel may not be configured so that UE 302 is able to detect the BSM(s).
Accordingly, the service announcement transmitted by UE 304 and other nearby UEs (e.g.,
a discovery signal) may be an upper layer signal and broadcasted (e.g., in a NR sidelink
broadcast). In some cases, UE 304 may include one or more parameters for itself in
the service announcement, including connection parameters and/or capabilities it possesses.
UE 302 may then monitor for and receive the broadcasted service announcement to identify
potential UEs for corresponding unicast connections. In some cases, UE 302 may identify
the potential UEs based on the capabilities each UE indicates in their respective
service announcements.
[0053] The service announcement may include information to assist UE 302 (e.g., or any initiating
UE) to identify the UE transmitting the service announcement (UE 304 in the example
of FIG. 3). For example, the service announcement may include channel information
where direct communication requests may be sent. In some cases, the channel information
may be specific to RAT (e.g., LTE or NR) and may include a resource pool within which
UE 302 transmits the communication request. Additionally, the service announcement
may include a specific destination address for the UE (e.g., a Layer 2 destination
address) if the destination address is different from the current address (e.g., the
address of the streaming provider or UE transmitting the service announcement). The
service announcement may also include a network or transport layer for UE 302 to transmit
a communication request on. For example, the network layer (also referred to as "Layer
3" or "L3") or the transport layer (also referred to as "Layer 4" or "L4") may indicate
a port number of an application for the UE transmitting the service announcement.
In some cases, no IP addressing may be needed if the signaling (e.g., PC5 signaling)
carries a protocol (e.g., a real-time transport protocol (RTP)) directly or gives
a locally-generated random protocol. Additionally, the service announcement may include
a type of protocol for credential establishment and QoS-related parameters.
[0054] After identifying a potential unicast connection target (UE 304 in the example of
FIG. 3), the initiating UE (UE 302 in the example of FIG. 3) may transmit a connection
request 315 to the identified target UE 304. In some cases, the connection request
315 may be a first RRC message transmitted by UE 302 to request a unicast connection
with UE 304 (e.g., an
RRCDirectConnectionSetupRequest message). For example, the unicast connection may utilize the PC5 interface for the
unicast link, and the connection request 315 may be an RRC connection setup request
message. Additionally, UE 302 may use a sidelink signaling radio bearer 305 to transport
the connection request 315.
[0055] After receiving the connection request 315, UE 304 may determine whether to accept
or reject the connection request 315. UE 304 may base this determination on a transmission/reception
capability, an ability to accommodate the unicast connection over the sidelink, a
particular service indicated for the unicast connection, the contents to be transmitted
over the unicast connection, or a combination thereof. For example, if UE 302 wants
to use a first RAT to transmit or receive data, but UE 304 does not support the first
RAT, then UE 304 may reject the connection request 315. Additionally or alternatively,
UE 304 may reject the connection request 315 based on being unable to accommodate
the unicast connection over the sidelink due to a limited radio resource, a scheduling
issue, etc. Accordingly, UE 304 may transmit an indication of whether the request
is accepted or rejected in a connection response 320. Similar to UE 302 and the connection
request 315, UE 304 may use a sidelink signaling radio bearer 310 to transport the
connection response 320. Additionally, the connection response 320 may be a second
RRC message transmitted by UE 304 in response to the connection request 315 (e.g.,
an
RRCDirectConnectionResponse message).
[0056] In some cases, sidelink signaling radio bearers 305 and 310 may be the same sidelink
radio signal bearer or may be separate sidelink signaling radio bearers. Accordingly,
a radio link control (RLC) layer acknowledged mode (AM) may be used for sidelink signaling
radio bearers 305 and 310. A UE that supports the unicast connection may listen on
a logical channel associated with the sidelink signaling radio bearers. In some cases,
the AS layer (i.e., Layer 2) may pass information directly through RRC signaling (e.g.,
control plane) instead of a V2X layer (e.g., data plane).
[0057] If the connection response 320 indicates that UE 304 accepted the connection request
315, UE 302 may then transmit a connection establishment 325 message on the sidelink
signaling radio bearer 305 to indicate that the unicast connection setup is complete.
In some cases, the connection establishment 325 may be a third RRC message (e.g.,
an
RRCDirectConnectionSetupComplete message). Each of the connection request 315, the connection response 320, and the
connection establishment 325 may use a basic capability when being transported from
one UE to the other UE to enable each UE to be able to receive and decode the corresponding
transmission (e.g., RRC message).
[0058] Additionally, identifiers may be used for each of the connection request 315, the
connection response 320, and the connection establishment 325 (e.g., the RRC signaling).
For example, the identifiers may indicate which UE 302/304 is transmitting which message
and/or which UE 302/304 the message is intended for. For physical (PHY) channels,
the RRC signaling and any subsequent data transmissions may use the same identifier
(e.g., Layer 2 IDs). However, for logical channels, the identifiers may be separate
for the RRC signaling and for the data transmissions. For example, on the logical
channels, the RRC signaling and the data transmissions may be treated differently
and have different acknowledgement (ACK) feedback messaging. In some cases, for the
RRC messaging, a physical (PHY) layer ACK may be used for ensuring the corresponding
messages are transmitted and received properly.
[0059] One or more information elements may be included in the connection request 315 and/or
the connection response 320 for UE 302 and/or UE 304, respectively, to enable negotiation
of corresponding AS layer parameters for the unicast connection. For example, UE 302
and/or UE 304 may include packet data convergence protocol (PDCP) parameters in a
corresponding unicast connection setup message to set a PDCP context for the unicast
connection. In some cases, the PDCP context may indicate whether or not PDCP duplication
is utilized for the unicast connection. Additionally, UE 302 and/or UE 304 may include
RLC parameters when establishing the unicast connection to set an RLC context of the
unicast connection. For example, the RLC context may indicate whether an AM (e.g.,
a reordering timer (t-reordering) is used) or an unacknowledged mode (UM) is used
for the RLC layer of the unicast communications.
[0060] Additionally, UE 302 and/or UE 304 may include medium access control (MAC) parameters
to set a MAC context for the unicast connection. In some cases, the MAC context may
enable resource selection algorithms, a hybrid automatic repeat request (HARQ) feedback
scheme (e.g., ACK or negative ACK (NACK) feedback), parameters for the HARQ feedback
scheme, carrier aggregation, or a combination thereof for the unicast connection.
Additionally, UE 302 and/or UE 304 may include PHY layer parameters when establishing
the unicast connection to set a PHY layer context for the unicast connection. For
example, the PHY layer context may indicate a transmission format (unless transmission
profiles are included for each UE 302/304) and a radio resource configuration (e.g.,
bandwidth part (BWP), numerology, etc.) for the unicast connection. These information
elements may be supported for different frequency range configurations (e.g., FR1
and FR2).
[0061] In some cases, a security context may also be set for the unicast connection (e.g.,
after the connection establishment 325 message is transmitted). Before a security
association (e.g., security context) is established between UE 302 and UE 304, the
sidelink signaling radio bearers 305 and 310 may not be protected. After a security
association is established, the sidelink signaling radio bearers 305 and 310 may be
protected. Accordingly, the security context may enable secure data transmissions
over the unicast connection and the sidelink signaling radio bearers 305 and 310.
Additionally, IP layer parameters (e.g., link-local IPv4 or IPv6 addresses) may also
be negotiated. In some cases, the IP layer parameters may be negotiated by an upper
layer control protocol running after RRC signaling is established (e.g., the unicast
connection is established). As noted above, UE 304 may base its decision on whether
to accept or reject the connection request 315 on a particular service indicated for
the unicast connection and/or the contents to be transmitted over the unicast connection
(e.g., upper layer information). The particular service and/or contents may be also
indicated by an upper layer control protocol running after RRC signaling is established.
[0062] After the unicast connection is established, UE 302 and UE 304 may communicate using
the unicast connection over a sidelink 330, where sidelink data 335 is transmitted
between the two UEs 302 and 304. The sidelink 330 may correspond to sidelinks 162
and/or 168 in FIG. 1 and/or wireless unicast sidelink 242 in FIGS. 2A and 2B. In some
cases, the sidelink data 335 may include RRC messages transmitted between the two
UEs 302 and 304. To maintain this unicast connection on sidelink 330, UE 302 and/or
UE 304 may transmit a keep alive message (e.g.,
RRCDirectLinkAlive message, a fourth RRC message, etc.). In some cases, the keep alive message may be
triggered periodically or on-demand (e.g., event-triggered). Accordingly, the triggering
and transmission of the keep alive message may be invoked by UE 302 or by both UE
302 and UE 304. Additionally or alternatively, a MAC control element (CE) (e.g., defined
over sidelink 330) may be used to monitor the status of the unicast connection on
sidelink 330 and maintain the connection. When the unicast connection is no longer
needed (e.g., UE 302 travels far enough away from UE 304), either UE 302 and/or UE
304 may start a release procedure to drop the unicast connection over sidelink 330.
Accordingly, subsequent RRC messages may not be transmitted between UE 302 and UE
304 on the unicast connection.
[0063] FIG. 4 is a block diagram illustrating various components of an exemplary UE 400, according
to aspects of the disclosure. In an aspect, the UE 400 may correspond to any of the
UEs described herein. As a specific example, the UE 400 may be a V-UE, such as V-UE
160 in FIG. 1. For the sake of simplicity, the various features and functions illustrated
in the block diagram of FIG. 4 are connected together using a common data bus that
is meant to represent that these various features and functions are operatively coupled
together. Those skilled in the art will recognize that other connections, mechanisms,
features, functions, or the like, may be provided and adapted as necessary to operatively
couple and configure an actual UE. Further, it is also recognized that one or more
of the features or functions illustrated in the example of FIG. 4 may be further subdivided,
or two or more of the features or functions illustrated in FIG. 4 may be combined.
[0064] The UE 400 may include at least one transceiver 404 connected to one or more antennas
402 for communicating with other network nodes, such as V-UEs (e.g., V-UEs 160), infrastructure
access points (e.g., roadside access point 164), P-UEs (e.g., UEs 104), base stations
(e.g., base stations 102), etc., via at least one designated RAT (e.g., C-V2X or IEEE
802.11p) over one or more communication links (e.g., communication links 120, sidelinks
162, 166, 168, mmW communication link 184). The transceiver 404 may be variously configured
for transmitting and encoding signals (e.g., messages, indications, information, and
so on), and, conversely, for receiving and decoding signals (e.g., messages, indications,
information, pilots, and so on) in accordance with the designated RAT.
[0065] As used herein, a "transceiver" may include at least one transmitter and at least
one receiver in an integrated device (e.g., embodied as a transmitter circuit and
a receiver circuit of a single communication device) in some implementations, may
comprise a separate transmitter device and a separate receiver device in some implementations,
or may be embodied in other ways in other implementations. In an aspect, a transmitter
may include or be coupled to a plurality of antennas (e.g., antenna(s) 402), such
as an antenna array, that permits the UE 400 to perform transmit "beamforming," as
described herein. Similarly, a receiver may include or be coupled to a plurality of
antennas (e.g., antenna(s) 402), such as an antenna array, that permits the UE 400
to perform receive beamforming, as described herein. In an aspect, the transmitter(s)
and receiver(s) may share the same plurality of antennas (e.g., antenna(s) 402), such
that the UE 400 can only receive or transmit at a given time, not both at the same
time. In some cases, a transceiver may not provide both transmit and receive functionalities.
For example, a low functionality receiver circuit may be employed in some designs
to reduce costs when providing full communication is not necessary (e.g., a receiver
chip or similar circuitry simply providing low-level sniffing).
[0066] The UE 400 may also include a satellite positioning service (SPS) receiver 406. The
SPS receiver 406 may be connected to the one or more antennas 402 for receiving satellite
signals. The SPS receiver 406 may comprise any suitable hardware and/or software for
receiving and processing SPS signals, such as global positioning system (GPS) signals.
The SPS receiver 406 requests information and operations as appropriate from the other
systems, and performs the calculations necessary to determine the UE's 400 position
using measurements obtained by any suitable SPS algorithm.
[0067] One or more sensors 408 may be coupled to a processing system 410 to provide information
related to the state and/or environment of the UE 400, such as speed, heading (e.g.,
compass heading), headlight status, gas mileage, etc. By way of example, the one or
more sensors 408 may include a speedometer, a tachometer, an accelerometer (e.g.,
a microelectromechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor
(e.g., a compass), an altimeter (e.g., a barometric pressure altimeter), etc.
[0068] The processing system 410 may include one or more microprocessors, microcontrollers,
ASICs, processing cores, digital signal processors, or the like that provide processing
functions, as well as other calculation and control functionality. The processing
system 410 may include any form of logic suitable for performing, or causing the components
of the UE 400 to perform, at least the techniques provided herein.
[0069] The processing system 410 may also be coupled to a memory 414 for storing data and
software instructions for executing programmed functionality within the UE 400. The
memory 414 may be on-board the processing system 410 (e.g., within the same integrated
circuit (IC) package), and/or the memory 414 may be external to the processing system
410 and functionally coupled over a data bus.
[0070] The UE 400 may include a user interface 450 that provides any suitable interface
systems, such as a microphone/speaker 452, keypad 454, and display 456 that allow
user interaction with the UE 400. The microphone/speaker 452 provides for voice communication
services with the UE 400. The keypad 454 comprises any suitable buttons for user input
to the UE 400. The display 456 comprises any suitable display, such as, for example,
a backlit liquid crystal display (LCD), and may further include a touch screen display
for additional user input modes.
[0071] In an aspect, the UE 400 may include a sidelink manager 470 coupled to the processing
system 410. The sidelink manager 470 (which may correspond to sidelink manager 170
in FIG. 1) may be a hardware, software, or firmware component that, when executed,
causes the UE 400 to perform the operations described herein. For example, the sidelink
manager 470 may be a software module stored in memory 414 and executable by the processing
system 410. As another example, the sidelink manager 470 may be a hardware circuit
(e.g., an ASIC, an FPGA, etc.) within the UE 400.
[0072] V2X communications in NR can occur in both sub-6 GHz frequency ranges (e.g., FR1)
and mmW frequency ranges (e.g., FR2). For mmW unicast D2D or V2V communications, the
initial communication establishment between neighboring devices (e.g., generally described
herein as V-UEs solely for illustration and not limitation) can be accomplished respectively
in two different approaches in two deployment options, a standalone (SA) deployment
and a non-standalone (NSA) deployment. In an SA deployment, only the mmW frequency
band is used. A mmW radio sidelink can be established between two V-UEs without the
support of any other previously established communication link that may be, for example,
in a different frequency band or in a different RAT.
[0073] Alternatively, establishment of the unicast mmW sidelink, including radio bearer
establishment and associated QoS negotiation, can occur in an NSA deployment option.
In an NSA deployment option, V-UEs can support communication in both FR1 and FR2.
Thus, it is possible that the D2D or V2V mmW sidelink in FR2 (which uses a specific
type of radio bearer configured for communication in mmW) is established with the
support of a previously established direct link/connection (e.g., sidelink 330 where
sidelink 330 is established in FR1) between the two V-UEs in FR1 with PC5-RRC signaling
and/or device-to-device discovery mechanisms. In this approach, for example, one or
more signaling radio bearers (SRBs) may be established over the FR1 sidelink first,
and then one or more data radio bearers (DRBs) may be established over the FR2 sidelink.
[0074] Radio bearers are logical communication channels offered by Layer 2 (which includes
a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, and a
MAC layer) to higher layers (e.g., the RRC and AS layers) for the transfer of either
user data (on DRBs) for a communication session, or control data (on SRBs) for the
communication session. An SRB carries dedicated control channel (DCCH) signaling data
for a communication session. (A DCCH is a point-to-point dedicated channel for transmitting
control information between a UE and the network or between the UE and another UE.)
An SRB is used during connection establishment to deliver control signaling while
on the connection. During connection establishment, an RRC Connection Setup procedure
establishes the SRB. The SRB is then used to send all subsequent control signaling
(e.g., physical layer, MAC layer, and other access layer control information) to start
the desired communication session and establish the DRBs for the communication session.
A DRB carries dedicated traffic channel (DTCH) data for a communication session. (A
DTCH is a point-to-point dedicated channel for transmitting user/application data/traffic
between a UE and the network or between the UE and another UE.) Establishment of the
DRB(s) is achieved using a radio bearer (RB) Setup procedure on the SRB. The RB Setup
procedure configures how both the DCCH and DTCH will be carried on the respective
radio bearers.
[0075] Using the SRB, the configuration of the different access protocol layers are of a
semistatic nature. Physical layer control is of a more dynamic nature in order to
control resource allocation, in terms of time, frequency, space, and/or power. The
access protocol layer configurations over the SRB occur at the time the radio bearer
is being set up. The physical layer control and adaptation occur at the time the data
is being exchanged.
[0076] The various aspects disclosed herein include techniques for establishing a mmW D2D
data session in an NSA deployment. More specifically, the various aspects disclosed
include techniques for establishing a DRB in a mmW band (e.g., FR2) with the support
of a previously established communication session in an FR1 band. Given the nature
of mmW communications (e.g., short range, high propagation loss), the problems related
to beam discovery (e.g., the determination of the BPL that best serves the bidirectional
communication between the two UEs) need to be solved along with the problem of establishing
the radio bearers for the D2D/P2P/V2X unicast link.
[0077] The various aspects disclosed herein also include techniques for establishing the
unicast radio bearers for a mmW sidelink in an NSA deployment option. Use of a previously
established FR1 communication link makes the establishment of QoS-based FR2 radio
bearers possible for mmW D2D or V2X unicast communications.
[0078] FIG. 5 illustrates an exemplary flow between an initiator device 520 and a target device
530, according to aspects of the disclosure. The devices 520 and 530 may be UEs (e.g.,
any of the UEs described herein). In the example of FIG. 5, because the FR2 sidelink
described below is established in NSA mode, the FR2 sidelink is established after
RRC setup of a sidelink in FR1, and this previously established sidelink in FR1 is
used to establish the new sidelink in FR2.
[0079] At 502, a D2D discovery procedure can be performed at an application layer. For example,
a D2D (e.g., V2V, V2X, etc.) peer discovery procedure can be performed in FR1 via
broadcast/groupcast, as described above with reference to FIG. 3, using V2V for illustration.
For example, the initiator device 520 may identify and locate candidate devices for
unicast communications based on a BSM broadcasted by nearby UEs (e.g., target device
530). The BSM may include location information (e.g., GPS coordinates) of the broadcasting
or groupcasting UE, security and identity information, and vehicle information (e.g.,
speed, maneuver, size, etc.) for the corresponding device, as appropriate. This service
announcement may be an upper layer signal.
[0080] At 504, the devices 520 and 530 establish an RRC connection and an SRB on a unicast
link in FR1 via a D2D RRC interface (e.g., an RRC procedure over the PC5 interface)
and D2D signaling (e.g., PC5-S), as discussed above with reference to FIG. 3. As discussed
above with reference to FIG. 3, a PC5 unicast RRC establishment in FR1 may also include
a capability exchange between devices 520 and 530. Such capabilities may include,
for example, whether the devices 520 and 530 support an FR2 band and simultaneous
transmission and reception in both FR1 and FR2. As used herein, the term "simultaneous"
communication on the first frequency band and the second frequency band means that
a device is capable of communicating over both frequency bands during overlapping
times, but does not require that any device is sending and/or receiving data on both
frequency bands at the same time.
[0081] At 506, the initiator device 520 determines that it has a new data flow for target
device 530 that needs a new sidelink radio bearer (SLRB) because, for example, the
new data flow requires a certain QoS (e.g., a certain data rate, throughput, latency,
etc.). Based on configuration information (e.g., from a network entity, such as a
serving base station or an application server over a Uu interface), negotiation (e.g.,
with the target device 530 over a PC5-RRC interface or with a network entity over
a Uu interface), or decision to support a specific QoS-to-SLRB mapping, the initiator
device 520 determines that the new SLRB is to be in FR2. In an aspect, the configuration
or QoS-to-SLRB mapping may indicate that for a data flow having a QoS requirement
in terms of latency or throughput above some threshold, the initiator device 520 will
attempt to establish an additional sidelink in FR2. In an aspect, a negotiation with
the network entity or the target device 530 may include the initiator device 520 providing
options to the target device 530 and the target device 530 making the decision.
[0082] At 508, having determined to establish an SLRB sidelink in FR2 with target device
530, the initiator device 520 sends an RRC reconfiguration message (e.g., an
RRCDirectConnectionReconfiguration message) to the target device 530 over the previously established SRB. In addition
to normal PDCP/RLC/MAC layer configuration, the radio bearer configuration process
includes mmW physical layer configurations for beam direction(s) and resource, timing,
location, and/or sequence ID parameters for L1/L2 layer procedures.
[0083] At 510, the devices 520 and 530 perform PHY/MAC procedures in FR2 for the new mmW
sidelink. The devices 520 and 530 perform PHY/MAC procedures in FR2 to determine the
serving BPL and synchronization and to initiate a mmW QoS-based V2V unicast link as
requested in stage 508. The PHY/MAC procedures may include determining the direction
of the transmit beam(s) used by the initiator device 520 and the receive beam(s) used
by the target device 530. Specifically, in stages 502 and/or 504, the devices 520
and 530 exchange their geographic locations (e.g., GPS coordinates) and possibly information
describing their current paths (e.g., direction of travel, speed, etc.). Based on
these known locations, the devices 520 and 530 can aim their respective transmit and
receive beam(s) as close as possible to the estimated direction of the other device.
That is, a transmitter (e.g., initiator device 520) can only aim a transmit beam in
certain directions, and therefore, may not be able to aim a transmit beam exactly
at the estimated location of the target device 530. Instead, it selects the transmit
beam(s) that can be directed in the direction(s) closest to the estimated direction
of the target device 530. The same applies to receive beams of a receiver (e.g., target
device 530).
[0084] At 512, the initiator device 520 sends an RRC reconfiguration complete message (e.g.,
RRCDirectConnectionReconfigurationComplete) to the target device 530 informing the target device 530 that the FR2 sidelink has
been stablished. The initiator device 520 can then send the additional data flow (i.e.,
having the certain QoS requirement) over the newly established FR2 sidelink. In addition,
data can flow in the reverse direction, if desired, through reflective QoS.
[0085] In an alternative aspect, RRC establishment could occur in FR2 instead of FR1, and
the RRC session could be used to establish a data-only sidelink in FR1. In such a
case, an RRC session would be established in FR2, and the RRC reconfiguration messages
would be sent on FR2. In this alternative, the SRB would be established in the FR2
band and a new DRB would be established in the FR1 band.
[0086] It will be appreciated that in the first aspect discussed above, an FR2 band is used
after the RRC setup messages in the FR1 band to establish the new FR2 DRB, and data
is communicated in FR2 while control signaling is communicated on the SRB in FR1.
In the first aspect, the signaling on the SRB in FR1 is used to establish the new
mmW physical layer channel, and there is also a data session change as a new data
flow (on a DRB) is added in this new band. In the alternative aspect, signaling on
an SRB in FR2 can be used to establish a new FR1 DRB. Additionally, as noted above,
it will be appreciated that although FIG. 5 has been described generally in terms
of a V2V procedure, it is equally applicable to any D2D connection.
[0087] As will be appreciated, the aspects described above with reference to FIG. 5 provide
the advantage of speeding up BPL acquisition and resource utilization in the FR2 band
by using the information received over the previously established FR1 sidelink (e.g.,
at 504 of FIG. 5) and/or discovery procedure (e.g., at 502 of FIG. 5). For example,
by using the GPS locations and/or shared path information from both devices, the initiator
and target devices 520 and 530 are advantageously able to more accurately estimate
initial directions for the transmit and receive beams, resulting in more effectively
sweeping or scanning on a subset of transmit and receive beams, rather than having
to perform full beam sweeps/scans. Further, besides beam sweeping/scanning over a
limited set of beams to speed up BPL acquisition, air interface resource utilization
for transmit beam sweeping can be controlled from the supporting PC5 link in the FR1
band to advantageously minimize resource utilization and collisions in the FR2 band.
[0088] FIG. 6 illustrates an exemplary flow 600 for wireless communication, according to aspects
of the disclosure. The flow 600 may be performed by a first UE (e.g., an initiator
device), which may correspond to any of the UEs described herein.
[0089] At 610, the first UE establishes an SRB for a communication session with a second
UE (e.g., a target device, which may correspond to any of the UEs described herein)
on a first frequency band based on an RRC connection. In an aspect, operation 610
may be performed by tranceiver(s) 404, processing system 410, memory 414, and/or sidelink
manager 470, any or all of which may be considered means for performing this operation.
[0090] At 620, the first UE sends, to the second UE over the SRB on the first frequency
band, a first RRC message (e.g., an RRC sidelink reconfiguration message, such as
an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band.
In an aspect, operation 620 may be performed by tranceiver(s) 404, processing system
410, memory 414, and/or sidelink manager 470, any or all of which may be considered
means for performing this operation.
[0091] At 630, the first UE configures the DRB on the second frequency band based on one
or more parameters of a device-to-device discovery procedure performed with the second
UE over the first frequency band. In an aspect, operation 630 may be performed by
tranceiver(s) 404, processing system 410, memory 414, and/or sidelink manager 470,
any or all of which may be considered means for performing this operation.
[0092] In the flow 600, the first RRC message may include one or more parameters for establishing
the DRB on the second frequency band. In this aspect, the configuring at 630 may include
configuring the DRB based on the one or more parameters in the first RRC message and
the one or more parameters in the device-to-device discovery procedure performed with
the second UE in the first frequency band.
[0093] In the flow 600, the flow 600 may further include (not shown) establishing the RRC
connection for the communication session with the second UE, as described above with
reference to 504 of FIG. 5.
[0094] In the flow 600, the flow 600 may further include (not shown) receiving, from the
second UE, a second RRC message (e.g., an RRC sidelink reconfiguration complete message,
such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and sending user data for the communication
session to the second UE over the DRB on the second frequency band.
[0095] In the flow 600, where the first UE receives the second RRC message confirming that
the DRB has been successfully configured, the first UE may send the first RRC message
before the DRB is configured on the second frequency band and receive the second RRC
message after the DRB is configured.
[0096] In the flow 600, where user data is sent to the second UE over the DRB on the second
frequency band, the flow 600 may also include (not shown) sending user data for the
communication session to the second UE over a DRB on the first frequency band.
[0097] In the flow 600, where user data is sent to the second UE over the DRB on the first
frequency band, a QoS for the DRB on the first frequency band may be different from
a QoS for the DRB on the second frequency band.
[0098] In the flow 600, the flow 600 may further include (not shown) receiving, from the
second UE, a second RRC message on the SRB indicating that the DRB was unsuccessfully
configured on the second frequency band, and reconfiguring the DRB on the second frequency
band based on one or more different parameters from one or more parameters in the
first RRC message.
[0099] In the flow 600, the first frequency band may be an omni-directional frequency band
(e.g., FR1) and the second frequency band comprises a frequency band in which a directional
beam is used (e.g., FR2, FR3, FR4), or the first frequency band may be a frequency
band in which a directional beam is used and the second frequency band comprises an
omni-directional frequency band.
[0100] In the flow 600, the first UE may send the first RRC message over the first frequency
band as a groupcast or a broadcast.
[0101] In the flow 600, the first UE may be a first vehicle and the second UE may be a second
vehicle, a roadside object, a roadsign, or a pedestrian. The first RRC message may
be an RRC sidelink reconfiguration message, and the second RRC message may be an RRC
sidelink reconfiguration complete message.
[0102] In the flow 600, the first UE and the second UE may communicate over the first frequency
band and the second frequency band using a PC5 D2D interface.
[0103] In the flow 600, the flow 600 may also include (not shown) receiving, over the SRB,
capability information from the second UE indicating an ability of the second UE to
simultaneously communicate on the first frequency band and the second frequency band.
Alternatively, the flow 600 may include (not shown) sending, over the SRB, capability
information to the second UE indicating an ability of the first UE to simultaneously
communicate on the first frequency band and the second frequency band.
[0104] In the flow 600, the flow 600 may also include (not shown) determining to configure
the DRB on the second frequency band based on the first UE having a data flow to transmit
to the second UE having a given QoS requirement. The determination to configure the
DRB on the second frequency band may be further based on a configuration to use the
second frequency band for communication sessions having the given QoS requirement.
The configuration may be preconfigured, received from a network entity, negotiated
with the second UE, requested by the second UE, a determination at the first UE, or
any combination thereof.
[0105] In the flow 600, where the configuration is negotiated with the second UE, the negotiation
with the second UE may include (not shown) sending, to the second UE, an option to
use the second frequency band for the data flow, and receiving, from the second UE,
an indication to use the second frequency band for the data flow.
[0106] In the flow 600, the first UE may receive a user data flow from the second UE over
the DRB based on a reflective QoS procedure.
[0107] In the flow 600, one or more parameters in the first RRC message may include physical
layer configuration parameters for RF beam direction for the DRB on the second frequency
band, sequence identifier, and resource usage and timing information for Layer 1 and
Layer 2 procedures. The RF beam direction may be based on geographic locations of
the first UE and the second UE, or the RF beam direction may be based on a limited
angle beam sweep of predicted directions from the first UE to the second UE.
[0108] FIG. 7 illustrates an exemplary flow 700 for wireless communication, according to
aspects of the disclosure. The flow 700 may be performed by a first UE (e.g., an initiator
device), which may correspond to any of the UEs described herein.
[0109] At 710, the first UE establishes an SRB for a communication session with a second
UE (e.g., a target device, which may correspond to any of the UEs described herein)
on a first frequency band based on an RRC connection. In an aspect, operation 710
may be performed by tranceiver(s) 404, processing system 410, memory 414, and/or sidelink
manager 470, any or all of which may be considered means for performing this operation.
[0110] At 720, the first UE sends, to the second UE over the SRB on the first frequency
band, a first RRC message (e.g., an RRC sidelink reconfiguration message, such as
an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band,
the first RRC message including one or more parameters for establishing the DRB on
the second frequency band. In an aspect, operation 720 may be performed by tranceiver(s)
404, processing system 410, memory 414, and/or sidelink manager 470, any or all of
which may be considered means for performing this operation.
[0111] At 730, the first UE configures the DRB on the second frequency band based on the
one or more parameters in the first RRC message. In an aspect, operation 730 may be
performed by tranceiver(s) 404, processing system 410, memory 414, and/or sidelink
manager 470, any or all of which may be considered means for performing this operation.
[0112] In the flow 700, the configuring at 730 may include configuring the DRB based on
the one or more parameters in the first RRC message and one or more parameters in
a device-to-device discovery procedure performed with the second UE in the first frequency
band.
[0113] In the flow 700, the flow 700 may further include (not shown) establishing the RRC
connection for the communication session with the second UE, as described above with
reference to 504 of FIG. 5.
[0114] In the flow 700, the flow 700 may further include (not shown) receiving, from the
second UE, a second RRC message (e.g., an RRC sidelink reconfiguration complete message,
such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and sending user data for the communication
session to the second UE over the DRB on the second frequency band.
[0115] In the flow 700, where the first UE receives the second RRC message confirming that
the DRB has been successfully configured, the first UE may send the first RRC message
before the DRB is configured on the second frequency band and receive the second RRC
message after the DRB is configured.
[0116] In the flow 700, where user data is sent to the second UE over the DRB on the second
frequency band, the flow 700 may also include (not shown) sending user data for the
communication session to the second UE over a DRB on the first frequency band.
[0117] In the flow 700, where user data is sent to the second UE over the DRB on the first
frequency band, a QoS for the DRB on the first frequency band may be different from
a QoS for the DRB on the second frequency band.
[0118] In the flow 700, the flow 700 may further include (not shown) receiving, from the
second UE, a second RRC message on the SRB indicating that the DRB was unsuccessfully
configured on the second frequency band, and reconfiguring the DRB on the second frequency
band based on one or more different parameters from one or more parameters in the
first RRC message.
[0119] In the flow 700, the first frequency band may be an omni-directional frequency band
(e.g., FR1) and the second frequency band comprises a frequency band in which a directional
beam is used (e.g., FR2, FR3, FR4), or the first frequency band may be a frequency
band in which a directional beam is used and the second frequency band comprises an
omni-directional frequency band.
[0120] In the flow 700, the first UE may send the first RRC message over the first frequency
band as a groupcast or a broadcast.
[0121] In the flow 700, the first UE may be a first vehicle and the second UE may be a second
vehicle, a roadside object, a roadsign, or a pedestrian. The first RRC message may
be an RRC sidelink reconfiguration message, and the second RRC message may be an RRC
sidelink reconfiguration complete message.
[0122] In the flow 700, the first UE and the second UE may communicate over the first frequency
band and the second frequency band using a PC5 D2D interface.
[0123] In the flow 700, the flow 700 may also include (not shown) receiving, over the SRB,
capability information from the second UE indicating an ability of the second UE to
simultaneously communicate on the first frequency band and the second frequency band.
Alternatively, the flow 700 may include (not shown) sending, over the SRB, capability
information to the second UE indicating an ability of the first UE to simultaneously
communicate on the first frequency band and the second frequency band.
[0124] In the flow 700, the flow 700 may also include (not shown) determining to configure
the DRB on the second frequency band based on the first UE having a data flow to transmit
to the second UE having a given QoS requirement. The determination to configure the
DRB on the second frequency band may be further based on a configuration to use the
second frequency band for communication sessions having the given QoS requirement.
The configuration may be preconfigured, received from a network entity, negotiated
with the second UE, requested by the second UE, a determination at the first UE, or
any combination thereof.
[0125] In the flow 700, where the configuration is negotiated with the second UE, the negotiation
with the second UE may include (not shown) sending, to the second UE, an option to
use the second frequency band for the data flow, and receiving, from the second UE,
an indication to use the second frequency band for the data flow.
[0126] In the flow 700, the first UE may receive a user data flow from the second UE over
the DRB based on a reflective QoS procedure.
[0127] In the flow 700, one or more parameters in the first RRC message may include physical
layer configuration parameters for RF beam direction for the DRB on the second frequency
band, sequence identifier, and resource usage and timing information for Layer 1 and
Layer 2 procedures. The RF beam direction may be based on geographic locations of
the first UE and the second UE, or the RF beam direction may be based on a limited
angle beam sweep of predicted directions from the first UE to the second UE.
[0128] FIG. 8 illustrates an exemplary flow 800 for wireless communication, according to aspects
of the disclosure. The flow 800 may be performed by a second UE (e.g., a target device),
which may correspond to any of the UEs described herein.
[0129] At 810, the second UE establishes an SRB for a communication session with a first
UE (e.g., an initiator device, which may correspond to any of the UEs described herein)
on a first frequency band based on an RRC connection. In an aspect, operation 810
may be performed by tranceiver(s) 404, processing system 410, memory 414, and/or sidelink
manager 470, any or all of which may be considered means for performing this operation.
[0130] At 820, the second UE receives, from the first UE over the SRB on the first frequency
band, a first RRC message (e.g., an RRC sidelink reconfiguration message, such as
an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band.
In an aspect, operation 820 may be performed by tranceiver(s) 404, processing system
410, memory 414, and/or sidelink manager 470, any or all of which may be considered
means for performing this operation.
[0131] At 830, the second UE configures the DRB on the second frequency band based on one
or more parameters of a device-to-device discovery procedure performed with the first
UE over the first frequency band. In an aspect, operation 830 may be performed by
tranceiver(s) 404, processing system 410, memory 414, and/or sidelink manager 470,
any or all of which may be considered means for performing this operation.
[0132] In the flow 800, the first RRC message may include one or more parameters for establishing
the DRB on the second frequency band. In this aspect, the configuring at 830 may include
configuring the DRB based on the one or more parameters in the first RRC message and
the one or more parameters in the device-to-device discovery procedure performed with
the second UE in the first frequency band.
[0133] In the flow 800, the flow 800 may further include (not shown) establishing the RRC
connection for the communication session with the first UE, as described above with
reference to 504 of FIG. 5.
[0134] In the flow 800, the flow 800 may further include (not shown) sending, to the first
UE, a second RRC message (e.g., an RRC sidelink reconfiguration complete message,
such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and receiving user data for the communication
session from the first UE over the DRB on the second frequency band.
[0135] In the flow 800, where the second UE sends the second RRC message confirming that
the DRB has been successfully configured, the second UE may receive the first RRC
message before the DRB is configured on the second frequency band and send the second
RRC message after the DRB is configured.
[0136] In the flow 800, where user data is received from the first UE over the DRB on the
second frequency band, the flow 800 may also include (not shown) receiving user data
for the communication session from the first UE over a DRB on the first frequency
band.
[0137] In the flow 800, where user data is received from the first UE over the DRB on the
first frequency band, a QoS for the DRB on the first frequency band may be different
from a QoS for the DRB on the second frequency band.
[0138] In the flow 800, the flow 800 may further include (not shown) sending, to the first
UE, a second RRC message on the SRB indicating that the DRB was unsuccessfully configured
on the second frequency band, and reconfiguring the DRB on the second frequency band
based on one or more different parameters from one or more parameters in the first
RRC message.
[0139] In the flow 800, the first frequency band may be an omni-directional frequency band
(e.g., FR1) and the second frequency band comprises a frequency band in which a directional
beam is used (e.g., FR2, FR3, FR4), or the first frequency band may be a frequency
band in which a directional beam is used and the second frequency band comprises an
omni-directional frequency band.
[0140] In the flow 800, the second UE may receive the first RRC message over the first frequency
band as a groupcast or a broadcast.
[0141] In the flow 800, the first UE may be a first vehicle and the second UE may be a second
vehicle, a roadside object, a roadsign, or a pedestrian. The first RRC message may
be an RRC sidelink reconfiguration message, and the second RRC message may be an RRC
sidelink reconfiguration complete message.
[0142] In the flow 800, the first UE and the second UE may communicate over the first frequency
band and the second frequency band using a PC5 D2D interface.
[0143] In the flow 800, the flow 800 may also include (not shown) sending, over the SRB,
capability information to the first UE indicating an ability of the second UE to simultaneously
communicate on the first frequency band and the second frequency band. Alternatively,
the flow 800 may include (not shown) receiving, over the SRB, capability information
from the first UE indicating an ability of the first UE to simultaneously communicate
on the first frequency band and the second frequency band.
[0144] In the flow 800, the second UE may send a user data flow to the first UE over the
DRB based on a reflective QoS procedure.
[0145] In the flow 800, one or more parameters in the first RRC message may include physical
layer configuration parameters for RF beam direction for the DRB on the second frequency
band, sequence identifier, and resource usage and timing information for Layer 1 and
Layer 2 procedures. The RF beam direction may be based on geographic locations of
the first UE and the second UE, or the RF beam direction may be based on a limited
angle beam sweep of predicted directions from the first UE to the second UE.
[0146] FIG. 9 illustrates an exemplary flow 900 for wireless communication, according to aspects
of the disclosure. The flow 900 may be performed by a second UE (e.g., a target device),
which may correspond to any of the UEs described herein.
[0147] At 910, the second UE establishes an SRB for a communication session with a first
UE on a first frequency band based on an RRC connection. In an aspect, operation 910
may be performed by tranceiver(s) 404, processing system 410, memory 414, and/or sidelink
manager 470, any or all of which may be considered means for performing this operation.
[0148] At 920, the second UE receives, from the first UE over the SRB on the first frequency
band, a first RRC message (e.g., an RRC sidelink reconfiguration message, such as
an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band,
the first RRC message including one or more parameters for establishing the DRB on
the second frequency band. In an aspect, operation 920 may be performed by tranceiver(s)
404, processing system 410, memory 414, and/or sidelink manager 470, any or all of
which may be considered means for performing this operation.
[0149] At 930, the second UE configures the DRB on the second frequency band based on the
one or more parameters in the first RRC message. In an aspect, operation 930 may be
performed by tranceiver(s) 404, processing system 410, memory 414, and/or sidelink
manager 470, any or all of which may be considered means for performing this operation.
[0150] In the flow 900, the configuring at 930 may include configuring the DRB based on
the one or more parameters in the first RRC message and one or more parameters in
a device-to-device discovery procedure performed with the second UE in the first frequency
band.
[0151] In the flow 900, the flow 900 may further include (not shown) establishing the RRC
connection for the communication session with the first UE, as described above with
reference to 504 of FIG. 5.
[0152] In the flow 900, the flow 900 may further include (not shown) sending, to the first
UE, a second RRC message (e.g., an RRC sidelink reconfiguration complete message,
such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and receiving user data for the communication
session from the first UE over the DRB on the second frequency band.
[0153] In the flow 900, where the second UE sends the second RRC message confirming that
the DRB has been successfully configured, the second UE may receive the first RRC
message before the DRB is configured on the second frequency band and send the second
RRC message after the DRB is configured.
[0154] In the flow 900, where user data is received from the first UE over the DRB on the
second frequency band, the flow 900 may also include (not shown) receiving user data
for the communication session from the first UE over a DRB on the first frequency
band.
[0155] In the flow 900, where user data is received from the first UE over the DRB on the
first frequency band, a QoS for the DRB on the first frequency band may be different
from a QoS for the DRB on the second frequency band.
[0156] In the flow 900, the flow 900 may further include (not shown) sending, to the first
UE, a second RRC message on the SRB indicating that the DRB was unsuccessfully configured
on the second frequency band, and reconfiguring the DRB on the second frequency band
based on one or more different parameters from one or more parameters in the first
RRC message.
[0157] In the flow 900, the first frequency band may be an omni-directional frequency band
(e.g., FR1) and the second frequency band comprises a frequency band in which a directional
beam is used (e.g., FR2, FR3, FR4), or the first frequency band may be a frequency
band in which a directional beam is used and the second frequency band comprises an
omni-directional frequency band.
[0158] In the flow 900, the second UE may receive the first RRC message over the first frequency
band as a groupcast or a broadcast.
[0159] In the flow 900, the first UE may be a first vehicle and the second UE may be a second
vehicle, a roadside object, a roadsign, or a pedestrian. The first RRC message may
be an RRC sidelink reconfiguration message, and the second RRC message may be an RRC
sidelink reconfiguration complete message.
[0160] In the flow 900, the first UE and the second UE may communicate over the first frequency
band and the second frequency band using a PC5 D2D interface.
[0161] In the flow 900, the flow 900 may also include (not shown) sending, over the SRB,
capability information to the first UE indicating an ability of the second UE to simultaneously
communicate on the first frequency band and the second frequency band. Alternatively,
the flow 900 may include (not shown) receiving, over the SRB, capability information
from the first UE indicating an ability of the first UE to simultaneously communicate
on the first frequency band and the second frequency band.
[0162] In the flow 900, the second UE may send a user data flow to the first UE over the
DRB based on a reflective QoS procedure.
[0163] In the flow 900, one or more parameters in the first RRC message may include physical
layer configuration parameters for RF beam direction for the DRB on the second frequency
band, sequence identifier, and resource usage and timing information for Layer 1 and
Layer 2 procedures. The RF beam direction may be based on geographic locations of
the first UE and the second UE, or the RF beam direction may be based on a limited
angle beam sweep of predicted directions from the first UE to the second UE.
[0164] FIG. 10 illustrates an exemplary UE apparatus 1000, which may correspond to any of the UEs
described herein. The UE apparatus 1000 may include a memory 1010 (which may correspond
to memory 414), at least one transceiver 1020 (which may correspond to transceiver(s)
404), at least one processor 1030 (which may correspond to processing system 410),
and a sidelink manager 1040 (which may correspond to sidelink manager 470).
[0165] The sidelink manager 1040 may be a hardware, software, or firmware component that,
when executed, causes the UE apparatus 1000 to perform the operations described herein.
For example, the sidelink manager 1040 may be a software module stored in memory 1010
and executable by the at least one processor 1030. As another example, the sidelink
manager 1040 may be a hardware circuit (e.g., an ASIC, a field programmable gate array
(FPGA), etc.) coupled to or integrated into the at least one processor 1030.
[0166] The memory 1010, the at least one transceiver 1020, and the at least one processor
1030 may be communicatively coupled to each other over a data bus 1050. Where the
sidelink manager 1040 is separate from the memory 1010 and the at least one processor
1030, the sidelink manager 1040 may be communicatively coupled to the other components
of the UE apparatus 1000 over the data bus 1050.
[0167] In an aspect, the UE apparatus 1000 may be a first UE (e.g., an initiator device).
In a first example aspect (which may correspond to the technique illustrated in FIG.
6), where the UE apparatus 1000 is a first UE, the at least one processor 1030 and/or
the sidelink manager 1040 may be configured to establish, via the at least one transceiver
1020, an SRB for a communication session with a second UE (e.g., a target device,
which may correspond to any of the UEs described herein) on a first frequency band
based on an RRC connection.
[0168] In the first example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be further configured to cause the at least one transceiver 1020
to send, to the second UE over the SRB on the first frequency band, a first RRC message
(e.g., an RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band.
[0169] In the first example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be further configured to configure, via the at least one transceiver
1020, the DRB on the second frequency band based on one or more parameters of a device-to-device
discovery procedure performed with the second UE over the first frequency band.
[0170] In the first example aspect, the first RRC message may include one or more parameters
for establishing the DRB on the second frequency band. In this aspect, the at least
one processor 1030 and/or the sidelink manager 1040 being configured to configure
the DRB may include the at least one processor 1030 and/or the sidelink manager 1040
being configured to configure the DRB based on the one or more parameters in the first
RRC message and the one or more parameters in the device-to-device discovery procedure
performed with the second UE in the first frequency band.
[0171] In a second example aspect (which may correspond to the technique illustrated in
FIG. 7), where the UE apparatus 1000 is a first UE, the at least one processor 1030
and/or the sidelink manager 1040 may be configured to establish, via the at least
one transceiver 1020, an SRB for a communication session with a second UE (e.g., a
target device, which may correspond to any of the UEs described herein) on a first
frequency band based on an RRC connection.
[0172] In the second example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be further configured to cause the at least one transceiver 1020
to send, to the second UE over the SRB on the first frequency band, a first RRC message
(e.g., an RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band,
the first RRC message including one or more parameters for establishing the DRB on
the second frequency band.
[0173] In the second example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be further configured to configure, via the at least one transceiver
1020, the DRB on the second frequency band based on the one or more parameters in
the first RRC message.
[0174] In the second example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 being configured to configure the DRB may include the at least one processor
1030 and/or the sidelink manager 1040 being configured to configure the DRB based
on the one or more parameters in the first RRC message and one or more parameters
in a device-to-device discovery procedure performed with the second UE in the first
frequency band.
[0175] In both the first and second example aspect, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to establish, via the at least
one transceiver 1020, the RRC connection for the communication session with the second
UE, as described above with reference to 504 of FIG. 5.
[0176] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to receive, from the second UE
via the at least one transceiver 1020, a second RRC message (e.g., an RRC sidelink
reconfiguration complete message, such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and to send user data for the communication
session to the second UE over the DRB on the second frequency band.
[0177] In both the first and second example aspects, where the first UE receives the second
RRC message confirming that the DRB has been successfully configured, the at least
one processor 1030 and/or the sidelink manager 1040 may cause the at least one transceiver
1020 to send the first RRC message before the DRB is configured on the second frequency
band and to receive, via the at least one transceiver 1020, the second RRC message
after the DRB is configured.
[0178] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the second frequency band, the at least one processor 1030 and/or
the sidelink manager 1040 may also be configured to cause the at least one transceiver
1020 to send user data for the communication session to the second UE over a DRB on
the first frequency band.
[0179] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the first frequency band, a QoS for the DRB on the first frequency
band may be different from a QoS for the DRB on the second frequency band.
[0180] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to receive, from the second UE
via the at least one transceiver 1020, a second RRC message on the SRB indicating
that the DRB was unsuccessfully configured on the second frequency band, and to reconfigure
the DRB on the second frequency band based on one or more different parameters from
one or more parameters in the first RRC message.
[0181] In both the first and second example aspects, the first frequency band may be an
omni-directional frequency band (e.g., FR1) and the second frequency band comprises
a frequency band in which a directional beam is used (e.g., FR2, FR3, FR4), or the
first frequency band may be a frequency band in which a directional beam is used and
the second frequency band comprises an omni-directional frequency band.
[0182] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may cause the at least one transceiver 1020 to send the
first RRC message over the first frequency band as a groupcast or a broadcast.
[0183] In both the first and second example aspects, the first UE may be a first vehicle
and the second UE may be a second vehicle, a roadside object, a roadsign, or a pedestrian.
The first RRC message may be an RRC sidelink reconfiguration message, and the second
RRC message may be an RRC sidelink reconfiguration complete message.
[0184] In both the first and second example aspects, the first UE and the second UE may
communicate over the first frequency band and the second frequency band using a PC5
D2D interface.
[0185] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may be further configured to receive, over the SRB via the
at least one transceiver 1020, capability information from the second UE indicating
an ability of the second UE to simultaneously communicate on the first frequency band
and the second frequency band. Alternatively, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to cause the at least one transceiver
1020 to send, over the SRB, capability information to the second UE indicating an
ability of the first UE to simultaneously communicate on the first frequency band
and the second frequency band.
[0186] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may be further configured to determine to configure the
DRB on the second frequency band based on the first UE having a data flow to transmit
to the second UE having a given QoS requirement. The determination to configure the
DRB on the second frequency band may be further based on a configuration to use the
second frequency band for communication sessions having the given QoS requirement.
The configuration may be preconfigured, received from a network entity, negotiated
with the second UE, requested by the second UE, a determination at the first UE, or
any combination thereof.
[0187] In both the first and second example aspects, where the configuration is negotiated
with the second UE, the negotiation with the second UE may include the at least one
processor 1030 and/or the sidelink manager 1040 causing the at least one transceiver
1020 to send, to the second UE, an option to use the second frequency band for the
data flow, and to receive, from the second UE via the at least one transceiver 1020,
an indication to use the second frequency band for the data flow.
[0188] In both the first and second example aspects, the first UE may receive, via the at
least one transceiver 1020, a user data flow from the second UE over the DRB based
on a reflective QoS procedure.
[0189] In both the first and second example aspects, one or more parameters in the first
RRC message may include physical layer configuration parameters for RF beam direction
for the DRB on the second frequency band, sequence identifier, and resource usage
and timing information for Layer 1 and Layer 2 procedures. The RF beam direction may
be based on geographic locations of the first UE and the second UE, or the RF beam
direction may be based on a limited angle beam sweep of predicted directions from
the first UE to the second UE.
[0190] In an aspect, the UE apparatus 1000 may be a second UE (e.g., a target device). In
a first example aspect (which may correspond to the technique illustrated in FIG.
8), where the UE apparatus 1000 is a second UE, the at least one processor 1030 and/or
the sidelink manager 1040 may be configured to establish, via the at least one transceiver
1020, an SRB for a communication session with a first UE (e.g., an initiator device,
which may correspond to any of the UEs described herein) on a first frequency band
based on an RRC connection.
[0191] In the first example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be configured to receive, from the first UE over the SRB on the first
frequency band, via the at least one transceiver 1020, a first RRC message (e.g.,
an RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band.
[0192] In the first example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be configured to configure, via the at least one transceiver 1020,
the DRB on the second frequency band based on one or more parameters of a device-to-device
discovery procedure performed with the first UE over the first frequency band.
[0193] In the first example aspect, the first RRC message may include one or more parameters
for establishing the DRB on the second frequency band. In this aspect, the at least
one processor 1030 and/or the sidelink manager 1040 being configured to configure
the DRB may include the at least one processor 1030 and/or the sidelink manager 1040
being configured to configure the DRB based on the one or more parameters in the first
RRC message and the one or more parameters in the device-to-device discovery procedure
performed with the second UE in the first frequency band.
[0194] In a second example aspect (which may correspond to the technique illustrated in
FIG. 9), where the UE apparatus 1000 is a second UE, the at least one processor 1030
and/or the sidelink manager 1040 may be configured to establish, via the at least
one transceiver 1020, an SRB for a communication session with a first UE on a first
frequency band based on an RRC connection.
[0195] In the second example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be further configured to receive, from the first UE over the SRB
on the first frequency band, via the at least one transceiver 1020, a first RRC message
(e.g., an RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band,
the first RRC message including one or more parameters for establishing the DRB on
the second frequency band.
[0196] In the second example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 may be further configured to configure, via the at least one transceiver
1020, the DRB on the second frequency band based on the one or more parameters in
the first RRC message.
[0197] In the second example aspect, the at least one processor 1030 and/or the sidelink
manager 1040 being configured to configure the DRB may include the at least one processor
1030 and/or the sidelink manager 1040 being configured to configure the DRB based
on the one or more parameters in the first RRC message and one or more parameters
in a device-to-device discovery procedure performed with the second UE in the first
frequency band.
[0198] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to establish, via the at least
one transceiver 1020, the RRC connection for the communication session with the second
UE, as described above with reference to 504 of FIG. 5.
[0199] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to receive, from the second UE
via the at least one transceiver 1020, a second RRC message (e.g., an RRC sidelink
reconfiguration complete message, such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and to send user data for the communication
session to the second UE over the DRB on the second frequency band.
[0200] In both the first and second example aspects, where the first UE receives the second
RRC message confirming that the DRB has been successfully configured, the at least
one processor 1030 and/or the sidelink manager 1040 may cause the at least one transceiver
1020 to send the first RRC message before the DRB is configured on the second frequency
band and to receive, via the at least one transceiver 1020, the second RRC message
after the DRB is configured.
[0201] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the second frequency band, the at least one processor 1030 and/or
the sidelink manager 1040 may also be configured to cause the at least one transceiver
1020 to send user data for the communication session to the second UE over a DRB on
the first frequency band.
[0202] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the first frequency band, a QoS for the DRB on the first frequency
band may be different from a QoS for the DRB on the second frequency band.
[0203] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to receive, from the second UE
via the at least one transceiver 1020, a second RRC message on the SRB indicating
that the DRB was unsuccessfully configured on the second frequency band, and to reconfigure
the DRB on the second frequency band based on one or more different parameters from
one or more parameters in the first RRC message.
[0204] In both the first and second example aspects, the first frequency band may be an
omni-directional frequency band (e.g., FR1) and the second frequency band comprises
a frequency band in which a directional beam is used (e.g., FR2, FR3, FR4), or the
first frequency band may be a frequency band in which a directional beam is used and
the second frequency band comprises an omni-directional frequency band.
[0205] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may cause the at least one transceiver 1020 to send the
first RRC message over the first frequency band as a groupcast or a broadcast.
[0206] In both the first and second example aspects, the first UE may be a first vehicle
and the second UE may be a second vehicle, a roadside object, a roadsign, or a pedestrian.
The first RRC message may be an RRC sidelink reconfiguration message, and the second
RRC message may be an RRC sidelink reconfiguration complete message.
[0207] In both the first and second example aspects, the first UE and the second UE may
communicate over the first frequency band and the second frequency band using a PC5
D2D interface.
[0208] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may be further configured to receive, over the SRB via the
at least one transceiver 1020, capability information from the second UE indicating
an ability of the second UE to simultaneously communicate on the first frequency band
and the second frequency band. Alternatively, the at least one processor 1030 and/or
the sidelink manager 1040 may further be configured to cause the at least one transceiver
1020 to send, over the SRB, capability information to the second UE indicating an
ability of the first UE to simultaneously communicate on the first frequency band
and the second frequency band.
[0209] In both the first and second example aspects, the at least one processor 1030 and/or
the sidelink manager 1040 may be further configured to determine to configure the
DRB on the second frequency band based on the first UE having a data flow to transmit
to the second UE having a given QoS requirement. The determination to configure the
DRB on the second frequency band may be further based on a configuration to use the
second frequency band for communication sessions having the given QoS requirement.
The configuration may be preconfigured, received from a network entity, negotiated
with the second UE, requested by the second UE, a determination at the first UE, or
any combination thereof.
[0210] In both the first and second example aspects, where the configuration is negotiated
with the second UE, the negotiation with the second UE may include the at least one
processor 1030 and/or the sidelink manager 1040 causing the at least one transceiver
1020 to send, to the second UE, an option to use the second frequency band for the
data flow, and to receive, from the second UE via the at least one transceiver 1020,
an indication to use the second frequency band for the data flow.
[0211] In both the first and second example aspects, the first UE may receive, via the at
least one transceiver 1020, a user data flow from the second UE over the DRB based
on a reflective QoS procedure.
[0212] In both the first and second example aspects, one or more parameters in the first
RRC message may include physical layer configuration parameters for RF beam direction
for the DRB on the second frequency band, sequence identifier, and resource usage
and timing information for Layer 1 and Layer 2 procedures. The RF beam direction may
be based on geographic locations of the first UE and the second UE, or the RF beam
direction may be based on a limited angle beam sweep of predicted directions from
the first UE to the second UE.
[0213] FIG. 11 illustrates an exemplary UE apparatus 1100, which may correspond to any of the UEs
described herein. The UE apparatus 1100 may include means for storing 1110 (which
may correspond to memory 414), means for transceiving 1120 (which may correspond to
transceiver(s) 404), means for processing 1130 (which may correspond to processing
system 410), and a sidelink manager 1140 (which may correspond to sidelink manager
470).
[0214] The sidelink manager 1140 may be a hardware, software, or firmware component that,
when executed, causes the UE apparatus 1100 to perform the operations described herein.
For example, the sidelink manager 1140 may be a software module stored in means for
storing 1110 and executable by the means for processing 1130. As another example,
the sidelink manager 1140 may be a hardware circuit (e.g., an ASIC, a field programmable
gate array (FPGA), etc.) coupled to or integrated into the means for processing 1130.
[0215] The means for storing 1110, the means for transceiving 1120, and the means for processing
1130 may be communicatively coupled to each other over a data bus 1150. Where the
sidelink manager 1140 is separate from the means for storing 1110 and the means for
processing 1130, the sidelink manager 1140 may be communicatively coupled to the other
components of the UE apparatus 1100 over the data bus 1150.
[0216] In an aspect, the UE apparatus 1100 may be a first UE (e.g., an initiator device).
In a first example aspect (which may correspond to the technique illustrated in FIG.
6), where the UE apparatus 1100 is a first UE, the means for processing 1130 and/or
the sidelink manager 1140 may be configured to establish, via the means for transceiving
1120, an SRB for a communication session with a second UE (e.g., a target device,
which may correspond to any of the UEs described herein) on a first frequency band
based on an RRC connection.
[0217] In the first example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be further configured to cause the means for transceiving 1120 to send, to
the second UE over the SRB on the first frequency band, a first RRC message (e.g.,
an RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band.
[0218] In the first example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be further configured to configure, via the means for transceiving 1120,
the DRB on the second frequency band based on one or more parameters of a device-to-device
discovery procedure performed with the second UE over the first frequency band.
[0219] In the first example aspect, the first RRC message may include one or more parameters
for establishing the DRB on the second frequency band. In this aspect, the means for
processing 1130 and/or the sidelink manager 1140 being configured to configure the
DRB may include the means for processing 1130 and/or the sidelink manager 1140 being
configured to configure the DRB based on the one or more parameters in the first RRC
message and the one or more parameters in the device-to-device discovery procedure
performed with the second UE in the first frequency band.
[0220] In a second example aspect (which may correspond to the technique illustrated in
FIG. 7), where the UE apparatus 1100 is a first UE, the means for processing 1130
and/or the sidelink manager 1140 may be configured to establish, via the means for
transceiving 1120, an SRB for a communication session with a second UE (e.g., a target
device, which may correspond to any of the UEs described herein) on a first frequency
band based on an RRC connection.
[0221] In the second example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be further configured to cause the means for transceiving 1120 to send, to
the second UE over the SRB on the first frequency band, a first RRC message (e.g.,
an RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band,
the first RRC message including one or more parameters for establishing the DRB on
the second frequency band.
[0222] In the second example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be further configured to configure, via the means for transceiving 1120,
the DRB on the second frequency band based on the one or more parameters in the first
RRC message.
[0223] In the second example aspect, the means for processing 1130 and/or the sidelink manager
1140 being configured to configure the DRB may include the means for processing 1130
and/or the sidelink manager 1140 being configured to configure the DRB based on the
one or more parameters in the first RRC message and one or more parameters in a device-to-device
discovery procedure performed with the second UE in the first frequency band.
[0224] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to establish, via the means for
transceiving 1120, the RRC connection for the communication session with the second
UE, as described above with reference to 504 of FIG. 5.
[0225] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to receive, from the second UE
via the means for transceiving 1120, a second RRC message (e.g., an RRC sidelink reconfiguration
complete message, such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and to send user data for the communication
session to the second UE over the DRB on the second frequency band.
[0226] In both the first and second example aspects, where the first UE receives the second
RRC message confirming that the DRB has been successfully configured, the means for
processing 1130 and/or the sidelink manager 1140 may cause the means for transceiving
1120 to send the first RRC message before the DRB is configured on the second frequency
band and to receive, via the means for transceiving 1120, the second RRC message after
the DRB is configured.
[0227] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the second frequency band, the means for processing 1130 and/or
the sidelink manager 1140 may also be configured to cause the means for transceiving
1120 to send user data for the communication session to the second UE over a DRB on
the first frequency band.
[0228] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the first frequency band, a QoS for the DRB on the first frequency
band may be different from a QoS for the DRB on the second frequency band.
[0229] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to receive, from the second UE
via the means for transceiving 1120, a second RRC message on the SRB indicating that
the DRB was unsuccessfully configured on the second frequency band, and to reconfigure
the DRB on the second frequency band based on one or more different parameters from
one or more parameters in the first RRC message.
[0230] In both the first and second example aspects, the first frequency band may be an
omni-directional frequency band (e.g., FR1) and the second frequency band comprises
a frequency band in which a directional beam is used (e.g., FR2, FR3, FR4), or the
first frequency band may be a frequency band in which a directional beam is used and
the second frequency band comprises an omni-directional frequency band.
[0231] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may cause the means for transceiving 1120 to send the first
RRC message over the first frequency band as a groupcast or a broadcast.
[0232] In both the first and second example aspects, the first UE may be a first vehicle
and the second UE may be a second vehicle, a roadside object, a roadsign, or a pedestrian.
The first RRC message may be an RRC sidelink reconfiguration message, and the second
RRC message may be an RRC sidelink reconfiguration complete message.
[0233] In both the first and second example aspects, the first UE and the second UE may
communicate over the first frequency band and the second frequency band using a PC5
D2D interface.
[0234] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may be further configured to receive, over the SRB via the
means for transceiving 1120, capability information from the second UE indicating
an ability of the second UE to simultaneously communicate on the first frequency band
and the second frequency band. Alternatively, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to cause the means for transceiving
1120 to send, over the SRB, capability information to the second UE indicating an
ability of the first UE to simultaneously communicate on the first frequency band
and the second frequency band.
[0235] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may be further configured to determine to configure the
DRB on the second frequency band based on the first UE having a data flow to transmit
to the second UE having a given QoS requirement. The determination to configure the
DRB on the second frequency band may be further based on a configuration to use the
second frequency band for communication sessions having the given QoS requirement.
The configuration may be preconfigured, received from a network entity, negotiated
with the second UE, requested by the second UE, a determination at the first UE, or
any combination thereof.
[0236] In both the first and second example aspects, where the configuration is negotiated
with the second UE, the negotiation with the second UE may include the means for processing
1130 and/or the sidelink manager 1140 causing the means for transceiving 1120 to send,
to the second UE, an option to use the second frequency band for the data flow, and
to receive, from the second UE via the means for transceiving 1120, an indication
to use the second frequency band for the data flow.
[0237] In both the first and second example aspects, the first UE may receive, via the means
for transceiving 1120, a user data flow from the second UE over the DRB based on a
reflective QoS procedure.
[0238] In both the first and second example aspects, one or more parameters in the first
RRC message may include physical layer configuration parameters for RF beam direction
for the DRB on the second frequency band, sequence identifier, and resource usage
and timing information for Layer 1 and Layer 2 procedures. The RF beam direction may
be based on geographic locations of the first UE and the second UE, or the RF beam
direction may be based on a limited angle beam sweep of predicted directions from
the first UE to the second UE.
[0239] In an aspect, the UE apparatus 1100 may be a second UE (e.g., a target device). In
a first example aspect (which may correspond to the technique illustrated in FIG.
8), where the UE apparatus 1100 is a second UE, the means for processing 1130 and/or
the sidelink manager 1140 may be configured to establish, via the means for transceiving
1120, an SRB for a communication session with a first UE (e.g., an initiator device,
which may correspond to any of the UEs described herein) on a first frequency band
based on an RRC connection.
[0240] In the first example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be configured to receive, from the first UE over the SRB on the first frequency
band, via the means for transceiving 1120, a first RRC message (e.g., an RRC sidelink
reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band.
[0241] In the first example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be configured to configure, via the means for transceiving 1120, the DRB
on the second frequency band based on one or more parameters of a device-to-device
discovery procedure performed with the first UE over the first frequency band.
[0242] In the first example aspect, the first RRC message may include one or more parameters
for establishing the DRB on the second frequency band. In this aspect, the means for
processing 1130 and/or the sidelink manager 1140 being configured to configure the
DRB may include the means for processing 1130 and/or the sidelink manager 1140 being
configured to configure the DRB based on the one or more parameters in the first RRC
message and the one or more parameters in the device-to-device discovery procedure
performed with the second UE in the first frequency band.
[0243] In a second example aspect (which may correspond to the technique illustrated in
FIG. 9), where the UE apparatus 1100 is a second UE, the means for processing 1130
and/or the sidelink manager 1140 may be configured to establish, via the means for
transceiving 1120, an SRB for a communication session with a first UE on a first frequency
band based on an RRC connection.
[0244] In the second example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be further configured to receive, from the first UE over the SRB on the first
frequency band, via the means for transceiving 1120, a first RRC message (e.g., an
RRC sidelink reconfiguration message, such as an
RRCDirectConnectionReconfiguration message) to establish a DRB for the communication session on a second frequency band,
the first RRC message including one or more parameters for establishing the DRB on
the second frequency band.
[0245] In the second example aspect, the means for processing 1130 and/or the sidelink manager
1140 may be further configured to configure, via the means for transceiving 1120,
the DRB on the second frequency band based on the one or more parameters in the first
RRC message.
[0246] In the second example aspect, the means for processing 1130 and/or the sidelink manager
1140 being configured to configure the DRB may include the means for processing 1130
and/or the sidelink manager 1140 being configured to configure the DRB based on the
one or more parameters in the first RRC message and one or more parameters in a device-to-device
discovery procedure performed with the second UE in the first frequency band.
[0247] In both the first and second example aspect, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to establish, via the means for
transceiving 1120, the RRC connection for the communication session with the second
UE, as described above with reference to 504 of FIG. 5.
[0248] In both the first and second example aspect, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to receive, from the second UE
via the means for transceiving 1120, a second RRC message (e.g., an RRC sidelink reconfiguration
complete message, such as an
RRCDirectConnectionReconfigurationComplete message) on the SRB, the second RRC message confirming that the DRB has been successfully
configured on the second frequency band, and to send user data for the communication
session to the second UE over the DRB on the second frequency band.
[0249] In both the first and second example aspect, where the first UE receives the second
RRC message confirming that the DRB has been successfully configured, the means for
processing 1130 and/or the sidelink manager 1140 may cause the means for transceiving
1120 to send the first RRC message before the DRB is configured on the second frequency
band and to receive, via the means for transceiving 1120, the second RRC message after
the DRB is configured.
[0250] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the second frequency band, the means for processing 1130 and/or
the sidelink manager 1140 may also be configured to cause the means for transceiving
1120 to send user data for the communication session to the second UE over a DRB on
the first frequency band.
[0251] In both the first and second example aspects, where user data is sent to the second
UE over the DRB on the first frequency band, a QoS for the DRB on the first frequency
band may be different from a QoS for the DRB on the second frequency band.
[0252] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to receive, from the second UE
via the means for transceiving 1120, a second RRC message on the SRB indicating that
the DRB was unsuccessfully configured on the second frequency band, and to reconfigure
the DRB on the second frequency band based on one or more different parameters from
one or more parameters in the first RRC message.
[0253] In both the first and second example aspects, the first frequency band may be an
omni-directional frequency band (e.g., FR1) and the second frequency band comprises
a frequency band in which a directional beam is used (e.g., FR2, FR3, FR4), or the
first frequency band may be a frequency band in which a directional beam is used and
the second frequency band comprises an omni-directional frequency band.
[0254] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may cause the means for transceiving 1120 to send the first
RRC message over the first frequency band as a groupcast or a broadcast.
[0255] In both the first and second example aspects, the first UE may be a first vehicle
and the second UE may be a second vehicle, a roadside object, a roadsign, or a pedestrian.
The first RRC message may be an RRC sidelink reconfiguration message, and the second
RRC message may be an RRC sidelink reconfiguration complete message.
[0256] In both the first and second example aspects, the first UE and the second UE may
communicate over the first frequency band and the second frequency band using a PC5
D2D interface.
[0257] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may be further configured to receive, over the SRB via the
means for transceiving 1120, capability information from the second UE indicating
an ability of the second UE to simultaneously communicate on the first frequency band
and the second frequency band. Alternatively, the means for processing 1130 and/or
the sidelink manager 1140 may further be configured to cause the means for transceiving
1120 to send, over the SRB, capability information to the second UE indicating an
ability of the first UE to simultaneously communicate on the first frequency band
and the second frequency band.
[0258] In both the first and second example aspects, the means for processing 1130 and/or
the sidelink manager 1140 may be further configured to determine to configure the
DRB on the second frequency band based on the first UE having a data flow to transmit
to the second UE having a given QoS requirement. The determination to configure the
DRB on the second frequency band may be further based on a configuration to use the
second frequency band for communication sessions having the given QoS requirement.
The configuration may be preconfigured, received from a network entity, negotiated
with the second UE, requested by the second UE, a determination at the first UE, or
any combination thereof.
[0259] In both the first and second example aspects, where the configuration is negotiated
with the second UE, the negotiation with the second UE may include the means for processing
1130 and/or the sidelink manager 1140 causing the means for transceiving 1120 to send,
to the second UE, an option to use the second frequency band for the data flow, and
to receive, from the second UE via the means for transceiving 1120, an indication
to use the second frequency band for the data flow.
[0260] In both the first and second example aspects, the first UE may receive, via the means
for transceiving 1120, a user data flow from the second UE over the DRB based on a
reflective QoS procedure.
[0261] In both the first and second example aspects, one or more parameters in the first
RRC message may include physical layer configuration parameters for RF beam direction
for the DRB on the second frequency band, sequence identifier, and resource usage
and timing information for Layer 1 and Layer 2 procedures. The RF beam direction may
be based on geographic locations of the first UE and the second UE, or the RF beam
direction may be based on a limited angle beam sweep of predicted directions from
the first UE to the second UE.
[0262] FIG. 12 illustrates an exemplary first UE apparatus 1200 (e.g., any of the UEs described
herein) represented as a series of interrelated functional modules, according to aspects
of the disclosure. In the illustrated example, a module for establishing 1210 may
correspond to, for example, a communication device (e.g., transceiver(s) 404) and/or
a processing system (e.g., processing system 410 and/or sidelink manager 470), optionally
in conjunction with a memory (e.g., memory 414 and/or sidelink manager 470), as discussed
herein. A module for sending 1220 may correspond to, for example, a communication
device (e.g., transceiver(s) 404) and/or a processing system (e.g., processing system
410 and/or sidelink manager 470), optionally in conjunction with a memory (e.g., memory
414 and/or sidelink manager 470), as discussed herein. A module for configuring 1230
may correspond to, for example, a communication device (e.g., transceiver(s) 404)
and/or a processing system (e.g., processing system 410 and/or sidelink manager 470),
optionally in conjunction with a memory (e.g., memory 414 and/or sidelink manager
470), as discussed herein.
[0263] FIG. 13 illustrates an exemplary first UE apparatus 1300 (e.g., any of the UEs described
herein) represented as a series of interrelated functional modules, according to aspects
of the disclosure. In the illustrated example, a module for establishing 1310 may
correspond to, for example, a communication device (e.g., transceiver(s) 404) and/or
a processing system (e.g., processing system 410 and/or sidelink manager 470), optionally
in conjunction with a memory (e.g., memory 414 and/or sidelink manager 470), as discussed
herein. A module for sending 1320 may correspond to, for example, a communication
device (e.g., transceiver(s) 404) and/or a processing system (e.g., processing system
410 and/or sidelink manager 470), optionally in conjunction with a memory (e.g., memory
414 and/or sidelink manager 470), as discussed herein. A module for configuring 1330
may correspond to, for example, a communication device (e.g., transceiver(s) 404)
and/or a processing system (e.g., processing system 410 and/or sidelink manager 470),
optionally in conjunction with a memory (e.g., memory 414 and/or sidelink manager
470), as discussed herein.
[0264] FIG. 14 illustrates an exemplary second UE apparatus 1400 (e.g., any of the UEs described
herein) represented as a series of interrelated functional modules, according to aspects
of the disclosure. In the illustrated example, a module for establishing 1410 may
correspond to, for example, a communication device (e.g., transceiver(s) 404) and/or
a processing system (e.g., processing system 410 and/or sidelink manager 470), optionally
in conjunction with a memory (e.g., memory 414 and/or sidelink manager 470), as discussed
herein. A module for receiving 1420 may correspond to, for example, a communication
device (e.g., transceiver(s) 404) and/or a processing system (e.g., processing system
410 and/or sidelink manager 470), optionally in conjunction with a memory (e.g., memory
414 and/or sidelink manager 470), as discussed herein. A module for configuring 1430
may correspond to, for example, a communication device (e.g., transceiver(s) 404)
and/or a processing system (e.g., processing system 410 and/or sidelink manager 470),
optionally in conjunction with a memory (e.g., memory 414 and/or sidelink manager
470), as discussed herein.
[0265] FIG. 15 illustrates an exemplary second UE apparatus 1500 (e.g., any of the UEs described
herein) represented as a series of interrelated functional modules, according to aspects
of the disclosure. In the illustrated example, a module for establishing 1510 may
correspond to, for example, a communication device (e.g., transceiver(s) 404) and/or
a processing system (e.g., processing system 410 and/or sidelink manager 470), optionally
in conjunction with a memory (e.g., memory 414 and/or sidelink manager 470), as discussed
herein. A module for receiving 1520 may correspond to, for example, a communication
device (e.g., transceiver(s) 404) and/or a processing system (e.g., processing system
410 and/or sidelink manager 470), optionally in conjunction with a memory (e.g., memory
414 and/or sidelink manager 470), as discussed herein. A module for configuring 1530
may correspond to, for example, a communication device (e.g., transceiver(s) 404)
and/or a processing system (e.g., processing system 410 and/or sidelink manager 470),
optionally in conjunction with a memory (e.g., memory 414 and/or sidelink manager
470), as discussed herein.
[0266] The functionality of the modules of FIGS. 12 to 15 may be implemented in various
ways consistent with the teachings herein. In some designs, the functionality of these
modules may be implemented as one or more electrical components. In some designs,
the functionality of these blocks may be implemented as a processing system including
one or more processor components. In some designs, the functionality of these modules
may be implemented using, for example, at least a portion of one or more integrated
circuits (e.g., an ASIC). As discussed herein, an integrated circuit may include a
processor, software, other related components, or some combination thereof. Thus,
the functionality of different modules may be implemented, for example, as different
subsets of an integrated circuit, as different subsets of a set of software modules,
or a combination thereof. Also, it will be appreciated that a given subset (e.g.,
of an integrated circuit and/or of a set of software modules) may provide at least
a portion of the functionality for more than one module.
[0267] In addition, the components and functions represented by FIGS. 12 to 15, as well
as other components and functions described herein, may be implemented using any suitable
means. Such means also may be implemented, at least in part, using corresponding structure
as taught herein. For example, the components described above in conjunction with
the "module for" components of FIGS. 12 to 15 also may correspond to similarly designated
"means for" functionality. Thus, in some aspects one or more of such means may be
implemented using one or more of processor components, integrated circuits, or other
suitable structure as taught herein, including as an algorithm. One skilled in the
art will recognize in this disclosure an algorithm represented in the prose described
above, as well as in sequences of actions that may be represented by pseudocode. For
example, the components and functions represented by FIGS. 12 to 15 may include code
for performing a LOAD operation, a COMPARE operation, a RETURN operation, an IF-THEN-ELSE
loop, and so on.
[0268] Those of skill in the art will appreciate that information and signals may be represented
using any of a variety of different technologies and techniques. For example, data,
instructions, commands, information, signals, bits, symbols, and chips that may be
referenced throughout the above description may be represented by voltages, currents,
electromagnetic waves, magnetic fields or particles, optical fields or particles,
or any combination thereof.
[0269] Further, those of skill in the art will appreciate that the various illustrative
logical blocks, modules, circuits, and algorithm steps described in connection with
the aspects disclosed herein may be implemented as electronic hardware, computer software,
or combinations of both. To clearly illustrate this interchangeability of hardware
and software, various illustrative components, blocks, modules, circuits, and steps
have been described above generally in terms of their functionality. Whether such
functionality is implemented as hardware or software depends upon the particular application
and design constraints imposed on the overall system. Skilled artisans may implement
the described functionality in varying ways for each particular application, but such
implementation decisions should not be interpreted as causing a departure from the
scope of the present disclosure.
[0270] The various illustrative logical blocks, modules, and circuits described in connection
with the aspects disclosed herein may be implemented or performed with a general purpose
processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate
or transistor logic, discrete hardware components, or any combination thereof designed
to perform the functions described herein. A general purpose processor may be a microprocessor,
but in the alternative, the processor may be any conventional processor, controller,
microcontroller, or state machine. A processor may also be implemented as a combination
of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality
of microprocessors, one or more microprocessors in conjunction with a DSP core, or
any other such configuration.
[0271] The methods, sequences and/or algorithms described in connection with the aspects
disclosed herein may be embodied directly in hardware, in a software module executed
by a processor, or in a combination of the two. A software module may reside in random
access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM
(EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a
removable disk, a CD-ROM, or any other form of non-transitory storage medium known
in the art. An exemplary storage medium may be coupled to the processor such that
the processor can read information from, and write information to, the storage medium.
In the alternative, the storage medium may be integral to the processor. The processor
and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal
(e.g., UE). In the alternative, the processor and the storage medium may reside as
discrete components in a user terminal.
[0272] In one or more exemplary aspects, the functions described may be implemented in hardware,
software, firmware, or any combination thereof. If implemented in software, the functions
may be stored on or transmitted over as one or more instructions or code on a computer-readable
medium. Computer-readable media includes both computer storage media and communication
media including any medium that facilitates transfer of a computer program from one
place to another. A storage media may be any available media that can be accessed
by a computer. By way of example, and not limitation, such computer-readable media
can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk
storage or other magnetic storage devices, or any other medium that can be used to
carry or store desired program code in the form of instructions or data structures
and that can be accessed by a computer. Also, any connection is properly termed a
computer-readable medium. For example, if the software is transmitted from a website,
server, or other remote source using a coaxial cable, fiber optic cable, twisted pair,
digital subscriber line (DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless
technologies such as infrared, radio, and microwave are included in the definition
of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc,
optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks
usually reproduce data magnetically, while discs reproduce data optically with lasers.
Combinations of the above should also be included within the scope of computer-readable
media.
[0273] While the foregoing disclosure shows illustrative aspects of the disclosure, it should
be noted that various changes and modifications could be made herein without departing
from the scope of the disclosure as defined by the appended claims.