(19)
(11)EP 2 537 277 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
17.02.2016 Bulletin 2016/07

(21)Application number: 11706416.2

(22)Date of filing:  17.02.2011
(51)Int. Cl.: 
H04L 1/16  (2006.01)
H04L 1/18  (2006.01)
(86)International application number:
PCT/US2011/025340
(87)International publication number:
WO 2011/103363 (25.08.2011 Gazette  2011/34)

(54)

CONTINUOUS MODE OPERATION FOR WIRELESS COMMUNICATIONS SYSTEMS

BETRIEB IM DAUERMODUS FÜR DRAHTLOSE KOMMUNIKATIONSSYSTEME

FONCTIONNEMENT EN MODE CONTINU POUR SYSTÈMES DE COMMUNICATION SANS FIL


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 16.02.2011 US 201113029072
17.02.2010 US 305490 P

(43)Date of publication of application:
26.12.2012 Bulletin 2012/52

(73)Proprietor: Qualcomm Incorporated
San Diego, CA 92121 (US)

(72)Inventors:
  • XU, Hao
    San Diego California 92121 (US)
  • VAJAPEYAM, Madhavan S.
    San Diego California 92121 (US)
  • BHUSHAN, Naga
    San Diego California 92121 (US)
  • CHEN, Wanshi
    San Diego California 92121 (US)
  • MALLADI, Durga Prasad
    San Diego California 92121 (US)

(74)Representative: Carstens, Dirk Wilhelm et al
Wagner & Geyer Gewürzmühlstraße 5
80538 München
80538 München (DE)


(56)References cited: : 
US-A1- 2009 268 707
  
  • DAJIE JIANG ET AL: "Uplink VoIP Performance in E-UTRAN TDD Mode", VEHICULAR TECHNOLOGY CONFERENCE, 2008. VTC SPRING 2008. IEEE, IEEE, PISCATAWAY, NJ, USA, 11 May 2008 (2008-05-11), pages 2482-2486, XP031256011, ISBN: 978-1-4244-1644-8
  • ERICSSON: "On Uplink Coverage for LTE", 3GPP DRAFT; R1-080865, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG1, no. Sorrento, Italy; 20080206, 6 February 2008 (2008-02-06), XP050109344, [retrieved on 2008-02-06]
  • SUSITAIVAL R ET AL: "LTE Coverage Improvement by TTI Bundling", 2009 IEEE 69TH VEHICULAR TECHNOLOGY CONFERENCE; APRIL 26-29, 2009, BARCELONA, SPAIN, IEEE, PISCATAWAY, NJ, USA, 26 April 2009 (2009-04-26), pages 1-5, XP031474607, ISBN: 978-1-4244-2517-4
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

TECHNICAL FIELD



[0001] Certain aspects of the present disclosure generally relate to wireless communications and, more particularly, to techniques for a continuous communications mode.

BACKGROUND



[0002] Wireless communication systems are widely deployed to provide various types of communication content such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE) systems, and orthogonal frequency division multiple access (OFDMA) systems.

[0003] Generally, a wireless multiple-access communication system can simultaneously support communication for multiple wireless terminals. Each terminal communicates with one or more base stations via transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the base stations to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the base stations. This communication link may be established via a single-in-single-out, multiple-in-signal-out or a multiple-in-multiple-out (MIMO) system.

[0004] A MIMO system employs multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. A MIMO channel formed by the NT transmit and NR receive antennas may be decomposed into NS independent channels, which are also referred to as spatial channels, where NS ≤ min{NT, NR}. Each of the NS independent channels corresponds to a dimension. The MIMO system can provide improved performance (e.g., higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and receive antennas are utilized.

[0005] A MIMO system supports a time division duplex (TDD) and frequency division duplex (FDD) systems. In a TDD system, the forward and reverse link transmissions are on the same frequency region so that the reciprocity principle allows the estimation of the forward link channel from the reverse link channel. This enables the access point to extract transmit beamforming gain on the forward link when multiple antennas are available at the access point.

[0006] Attention is drawn to the document entitled "Uplink VoIP Performance in E-UTRAN TDD Mode" by DAJIE JIANG ET AL, VEHICULAR TECHNOLOGY CONFERENCE, 2008. VTC SPRING 2008. IEEE, IEEE, PISCATAWAY, NJ, USA, 11 May 2008, pages 2482-2486, XP031256011, ISBN: 978-1-4244-1644-8. The paper evaluates the uplink VoIP performance in the E-UTRAN TDD mode for different scheduling methods and compares it with the capacity in FDD mode.

[0007] Attention is also drawn to document US2009268707 (A1), which describes methods for implementing transmission time interval (TTI) bundling, and a wireless transit/receive unit (WTRU) and a base station configured to process the methods. The method includes the WTRU receiving a TTI control signal and/or configuration message from a network and the WTRU transmitting TTI control signals to the network. The control signals and/or configuration message may be sent via Layer 1, Layer 2, or Layer 3 messages. Signaling may be implemented, for example, using or via an enhanced-absolute grant channel (E-AGCH), a high speed-shared control channel (HS-SCCH), Medium Access Control (MAC) headers, radio resource control messages, a logical channel ID, information elements, and the control signals and/or configuration may include, for example, information related to triggering criteria, activation and deactivation, number of retransmissions, handover related information and configuration information.

SUMMARY



[0008] In accordance with the present invention, a method for communications, as set forth in claims 1 and 9, and an apparatus for communications, as set forth in claims 7 and 11, are provided. Embodiments of the invention are claimed in the dependent claims.

[0009] Certain aspects of the present disclosure provide a method for communications in a wireless communications system. The method generally includes receiving configuration signaling from a base station to enter a continuous communications mode and processing bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

[0010] Certain aspects of the present disclosure provide an apparatus for communications in a wireless communications system. The apparatus generally includes means for receiving configuration signaling from a base station to enter a continuous communications mode and means for processing bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

[0011] Certain aspects of the present disclosure provide a computer-program product for communications in a wireless communications system, the computer-program product comprising a computer-readable medium. The computer-readable medium generally includes code for receiving configuration signaling from a base station to enter a continuous communications mode and processing bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

[0012] Certain aspects of the present disclosure provide a method for communications in a wireless communications system. The method generally includes transmitting configuration signaling to at least one user equipment (UE) to enter a continuous communications mode and processing bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

[0013] Certain aspects of the present disclosure provide an apparatus for communications in a wireless communications system. The apparatus generally includes means for transmitting configuration signaling to at least one user equipment (UE) to enter a continuous communications mode and means for processing bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

[0014] Certain aspects of the present disclosure provide a computer-program product for communications in a wireless communications system, the computer-program product comprising a computer-readable medium. The computer-readable medium generally includes code for transmitting configuration signaling to at least one user equipment (UE) to enter a continuous communications mode and processing bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

BRIEF DESCRIPTION OF THE DRAWINGS



[0015] The features, nature, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:

FIG. 1 is an illustration of a wireless communication system in accordance with various aspects set forth herein.

FIG. 2 is an illustration of an example wireless network environment that can be employed in conjunction with the various systems and methods described herein.

FIG. 3 is an illustration of an exemplary environment that facilitates continuous mode operation according to an embodiment.

FIG. 4 is a block diagram of an exemplary method, according to an embodiment.

FIG. 5 is a block diagram of an exemplary method, according to an embodiment.

FIG. 6 is an example message exchange for early termination of continuous communications mode, according to an embodiment.

FIG. 7-11 illustrate exemplary options for allocating resources in a continuous voice-over-internet-protocol transmission, according to certain example embodiments.


DESCRIPTION



[0016] The techniques described herein may be used for various wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms "networks" and "systems" are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA) and Low Chip Rate (LCR). cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM are part of Universal Mobile Telecommunication System (UMTS). Long Term Evolution (LTE) is an upcoming release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These various radio technologies and standards are known in the art. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

[0017] Single carrier frequency division multiple access (SC-FDMA), which utilizes single carrier modulation and frequency domain equalization, has similar performance and essentially the same overall complexity as those of an OFDMA system. SC-FDMA signal has lower peak-to-average power ratio (PAPR) because of its inherent single carrier structure. SC-FDMA has drawn great attention, especially in the uplink communications where lower PAPR greatly benefits the mobile terminal in terms of transmit power efficiency. It is currently a working assumption for uplink multiple access scheme in 3GPP Long Term Evolution (LTE), or Evolved UTRA.

[0018] Referring to Fig. 1, a multiple access wireless communication system according to one embodiment is illustrated. An access point 100 (AP) includes multiple antenna groups, one including 104 and 106, another including 108 and 110, and an additional including 112 and 114. In Fig. 1, only two antennas are shown for each antenna group, however, more or fewer antennas may be utilized for each antenna group. Access terminal 116 (AT) is in communication with antennas 112 and 114, where antennas 112 and 114 transmit information to access terminal 116 over forward link 120 and receive information from access terminal 116 over reverse link 118. Access terminal 122 is in communication with antennas 104 and 106, where antennas 104 and 106 transmit information to access terminal 122 over forward link 126 and receive information from access terminal 122 over reverse link 124. In a FDD system, communication links 118, 120, 124 and 126 may use different frequency for communication. For example, forward link 120 may use a different frequency than that used by reverse link 118.

[0019] Each group of antennas and/or the area in which they are designed to communicate is often referred to as a sector of the access point. In one embodiment, antenna groups are designed to communicate to access terminals in a sector of the areas covered by access point 100.

[0020] In communication over forward links 120 and 126, the transmitting antennas of access point 100 utilize beamforming in order to improve the signal-to-noise ratio of forward links for the different access terminals 116 and 122. Also, an access point using beamforming to transmit to access terminals scattered randomly through its coverage causes less interference to access terminals in neighboring cells than an access point transmitting through a single antenna to all its access terminals.

[0021] An access point may be a fixed station used for communicating with the terminals and may also be referred to as an access point, a Node B, or some other terminology. An access terminal may also be called a wireless terminal, user equipment (UE), a wireless communication device, terminal, or some other terminology.

[0022] FIG. 2 is a block diagram of an embodiment of a transmitter system 210 (also known as the access point) and a receiver system 250 (also known as access terminal) in a MIMO system 200. At the transmitter system 210, traffic data for a number of data streams is provided from a data source 212 to a transmit (TX) data processor 214.

[0023] In an embodiment, each data stream is transmitted over a respective transmit antenna. TX data processor 214 formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

[0024] The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (i.e., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed by processor 230. Instructions performed by processor 230 may be stored in memory 232, which may be coupled to processor 230. Memory 232 may be external or internal to processor 230.

[0025] The modulation symbols for all data streams are then provided to a TX MIMO processor 220, which may further process the modulation symbols (e.g., for OFDM). TX MIMO processor 220 then provides NT modulation symbol streams to NT transmitters (TMTR) 222a through 222t. In certain embodiments, TX MIMO processor 220 applies beamforming weights to the symbols of the data streams and to the antenna from which the symbol is being transmitted.

[0026] Each transmitter 222 receives and processes a respective symbol stream to provide one or more analog signals, and further conditions (e.g., amplifies, filters, and upconverts) the analog signals to provide a modulated signal suitable for transmission over the MIMO channel. NT modulated signals from transmitters 222a through 222t are then transmitted from NT antennas 224a through 224t, respectively.

[0027] At receiver system 250, the transmitted modulated signals are received by NR antennas 252a through 252r and the received signal from each antenna 252 is provided to a respective receiver (RCVR) 254a through 254r. Each receiver 254 conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

[0028] An RX data processor 260 then receives and processes the NR received symbol streams from NR receivers 254 based on a particular receiver processing technique to provide NT "detected" symbol streams. The RX data processor 260 then demodulates, deinterleaves, and decodes each detected symbol stream to recover the traffic data for the data stream. The processing by RX data processor 260 is complementary to that performed by TX MIMO processor 220 and TX data processor 214 at transmitter system 210.

[0029] A processor 270 periodically determines which pre-coding matrix to use. Processor 270 formulates a reverse link message comprising a matrix index portion and a rank value portion. Instructions performed by processor 270 may be stored in memory 272, which may be coupled to processor 270. Memory 272 may be external or internal to processor 270.

[0030] The reverse link message may comprise various types of information regarding the communication link and/or the received data stream. The reverse link message is then processed by a TX data processor 238, which also receives traffic data for a number of data streams from a data source 236, modulated by a modulator 280, conditioned by transmitters 254a through 254r, and transmitted back to transmitter system 210.

[0031] At transmitter system 210, the modulated signals from receiver system 250 are received by antennas 224, conditioned by receivers 222, demodulated by a demodulator 240, and processed by a RX data processor 242 to extract the reserve link message transmitted by the receiver system 250. Processor 230 then determines which pre-coding matrix to use for determining the beamforming weights and processes the extracted message.

[0032] In an aspect, logical channels are classified into Control Channels and Traffic Channels. Logical Control Channels comprise Broadcast Control Channel (BCCH) which is DL channel for broadcasting system control information, Paging Control Channel (PCCH) which is DL channel that transfers paging information, Multicast Control Channel (MCCH) which is Point-to-multipoint DL channel used for transmitting Multimedia Broadcast and Multicast Service (MBMS) scheduling and control information for one or several MTCHs. Generally, after establishing RRC connection this channel is only used by UEs that receive MBMS. Dedicated Control Channel (DCCH) is a Point-to-point bi-directional channel that transmits dedicated control information and used by UEs having an RRC connection. In aspect, Logical Traffic Channels comprise a Dedicated Traffic Channel (DTCH) which is a Point-to-point bi-directional channel, dedicated to one UE, for the transfer of user information, and a Multicast Traffic Channel (MTCH) for Point-to-multipoint DL channel for transmitting traffic data.

[0033] In an aspect, Transport Channels are classified into DL and UL. DL Transport Channels comprise a Broadcast Channel (BCH), Downlink Shared Data Channel (DL-SDCH) and a Paging Channel (PCH), the PCH for support of UE power saving (DRX cycle is indicated by the network to the UE), broadcasted over entire cell and mapped to PHY resources which can be used for other control/traffic channels. The UL Transport Channels comprise a Random Access Channel (RACH), a Request Channel (REQCH), a Uplink Shared Data Channel (UL-SDCH) and plurality of PHY channels. The PHY channels comprise a set of DL channels and UL channels.

[0034] The DL PHY channels comprise:

Common Pilot Channel (CPICH)

Synchronization Channel (SCH)

Common Control Channel (CCCH)

Shared DL Control Channel (SDCCH)

Multicast Control Channel (MCCH)

Shared UL Assignment Channel (SUACH)

Acknowledgement Channel (ACKCH)

DL Physical Shared Data Channel (DL-PSDCH)

UL Power Control Channel (UPCCH)

Paging Indicator Channel (PICH)

Load Indicator Channel (LICH)



[0035] The UL PHY Channels comprise:

Physical Random Access Channel (PRACH)

Channel Quality Indicator Channel (CQICH)

Acknowledgement Channel (ACKCH)

Antenna Subset Indicator Channel (ASICH)

Shared Request Channel (SREQCH)

UL Physical Shared Data Channel (UL-PSDCH)

Broadband Pilot Channel (BPICH)



[0036] In an aspect, a channel structure is provided that preserves low PAPR (at any given time, the channel is contiguous or uniformly spaced in frequency) properties of a single carrier waveform.

[0037] For the purposes of the present document, the following abbreviations apply:
AM
Acknowledged Mode
AMD
Acknowledged Mode Data
ARQ
Automatic Repeat Request
BCCH
Broadcast Control CHannel
BCH
Broadcast CHannel
C-
Control-
CCCH
Common Control CHannel
CCH
Control CHannel
CCTrCH
Coded Composite Transport Channel
CP
Cyclic Prefix
CRC
Cyclic Redundancy Check
CTCH
Common Traffic CHannel
DCCH
Dedicated Control CHannel
DCH
Dedicated CHannel
DL
DownLink
DSCH
Downlink Shared CHannel
DTCH
Dedicated Traffic CHannel
FACH
Forward link Access CHannel
FDD
Frequency Division Duplex
L1
Layer 1 (physical layer)
L2
Layer 2 (data link layer)
L3
Layer 3 (network layer)
LI
Length Indicator
LSB
Least Significant Bit
MAC
Medium Access Control
MBMS
Multimedia Broadcast and Multicast Service
MCCH
MBMS point-to-multipoint Control CHannel
MRW
Move Receiving Window
MSB
Most Significant Bit
MSCH
MBMS point-to-multipoint Scheduling CHannel
MTCH
MBMS point-to-multipoint Traffic CHannel
PCCH
Paging Control CHannel
PCH
Paging CHannel
PDU
Protocol Data Unit
PHY
PHYsical layer
PhyCH
Physical CHannels
RACH
Random Access CHannel
RLC
Radio Link Control
RRC
Radio Resource Control
SAP
Service Access Point
SDU
Service Data Unit
SHCCH
SHared channel Control CHannel
SN
Sequence Number
SUFI
SUper FIeld
TCH
Traffic CHannel
TDD
Time Division Duplex
TFI
Transport Format Indicator
TM
Transparent Mode
TMD
Transparent Mode Data
TTI
Transmission Time Interval
U-
User-
UE
User Equipment
UL
UpLink
UM
Unacknowledged Mode
UMD
Unacknowledged Mode Data
UMTS
Universal Mobile Telecommunications System
UTRA
UMTS Terrestrial Radio Access
UTRAN
UMTS Terrestrial Radio Access Network
MBSFN
multicast broadcast single frequency network
MCE
MBMS coordinating entity
MCH
multicast channel
DL-SCH
downlink shared channel
MSCH
MBMS control channel
PDCCH
physical downlink control channel
PDSCH
physical downlink shared channel
PUSCH
physical uplink shared channel


[0038] Certain aspects of the present disclosure provide techniques for facilitating a continuous mode operation in wireless communications systems, such as LTE systems.

[0039] It may be noted that standards for packet-based systems, such as LTE, have mainly focused on the best effort (BE) data traffic optimization. However, for voice-over-internet-protocol (VOIP) applications, there are some drawbacks, when compared to other systems, such as CDMA 1X, which are typically optimized only for voice.

[0040] One example drawback relates to the link budget issue that is inherent in time-division-multiplexing (TDM) systems. Bundling of transmissions with a single grant for multiple TTI transmissions requiring only a single HARQ feedback per bundle is allowed in LTE. However, since the LTE specification limits bundling to 4, link budget issues still exist for cell edge users. Moreover, with such bundling, there may always be a conflict because of the 16 ms transmission time interval (TTI) hybrid automatic repeat request (HARQ) turn around time and the typical 20 ms of VOIP packet arrival time.

[0041] According to certain aspects, a continuous mode operation for communication in a wireless system is provided by mapping the timing of bundled TTI transmissions to VOIP packet arrival time and eliminating the need to acknowledge the bundle. According to certain aspects, this technique may provide gain for link budget limited users, such as those at a cell edge. According to certain aspects, the continuous mode may be enabled and disabled based on location within a cell, for example, as determined by received signal strength at a UE.

[0042] The following description provides illustrative, but not limiting, examples of techniques for a continuous mode operation that may be utilized in VOIP applications. Those skilled in the art will recognize, however, that the techniques presented herein may be more generally applied to a variety of applications that may require consistent system resources for an extended period of time (e.g., over durations of seconds or minutes), such as applications where video and/or audio are streamed to mobile devices, such as smart phones and tablets.

[0043] Fig. 3 illustrates an example wireless environment 300, in which a continuous mode operation may be utilized, in accordance with aspects of the present disclosure. As shown, environment 300 includes base station 310, which is communicatively coupled to wireless terminal 320 and wireless terminal 330.

[0044] According to certain aspects, base station 310 may include a configuration component 312 to provide configuration data to each of wireless terminal 320 and wireless terminal 330 to enable a continuous mode operation. The wireless terminal 320 may include a configuration component 322 configured to receive the configuration data (or other signaling) from the base station 310 and enable/disable continuous mode communications accordingly.

[0045] For this particular embodiment illustrated in FIG. 3, a continuous mode operation between base station 310 and wireless terminal 320 may be facilitated, whereas base station 310 and wireless terminal 330 communicate via a regular transmission (e.g., with no bundling and/or conventional HARQ bundling). While in the continuous transmission mode, the base station 310 and wireless terminal 320 may utilize TTI bundles, with transmission times mapped to voice-over-internet-protocol (VOIP) arrival times. As illustrated, the base station 310 may include a bundling component 314 and mapping component 316 to bundle TTIs and map the bundled TTI transmission time to a VOIP arrival time. As the continuous mode may be applied on both uplink and downlink communications, the wireless terminal 320 may also include a bundling component 324 and mapping component 326.

[0046] Fig. 4 illustrates example operations 400 that may be performed, for example, by a base station (such as BS 310 of FIG. 3). The operations 400 begin, at 402, by transmitting configuration signaling to at least one user equipment (UE) to enter a continuous communications mode. In this manner, users may be semi-statically configured in continuous mode. For example, users can start and stop continuous transmission through PDCCH assignment and de-assignment.

[0047] At 404, bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to voice-over-internet-protocol (VOIP) arrival times are processed, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received. The processing may comprise receiving bundled TTI transmissions transmitted on an uplink from the UE or transmitting bundled TTI transmissions to the UE on the downlink.

[0048] Fig. 5 illustrates example operations 500 that may be performed, for example, by a user equipment (such as UE 320 of FIG. 3). The operations 500 begin, at 502, by receiving configuration signaling from a base station to enter a continuous communications mode. At 504, bundles of transmission time interval (TTI) transmissions having transmission times that are mapped to voice-over-internet-protocol (VOIP) arrival times are processed, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.

[0049] According to certain aspects, multiple users may be multiplexed within one resource block (RB) to trade off between link budget and user capacity. For example, frequency division multiplexing (FDM), code division multiplexing and frequency division multiplexing (CDM/FDM), or spatial division multiple access (SDMA) approaches may be used for VOIP enhancement. Users may also be time-multiplexed together, for example, with resources allocated based on their VOIP activity time.

[0050] Under some conditions, the continuous transmission mode described herein may provide various advantages, such as gain for link budget limited users (e.g., at the cell edge). According to certain aspects, higher layer signaling (to enable/disable) may be configured to reduce physical downlink control channel (PDCCH) overhead. Bundled transmissions, in general, may provide link budget gain with coding across bundled sub-frames, cross sub-frame channel estimation, and exploitation of time domain diversity gain. Different levels of bundling may be selected for different users (e.g., depending on link budget).

[0051] According to certain aspects, HARQ feedback is not required for the bundled transmissions mapped to VOIP arrival times. In addition to simplifying scheduling, this may also resolve the conflict between HARQ turnaround time and VOIP packet arrival time. Not requiring HARQ feedback also removes the need for acknowledgement (ACK) resources for the DL or UL.

[0052] As illustrated in FIG. 6, however, in some cases an ACK may be used to allow early termination and discontinuous reception (DRX). As illustrated, continuous mode may be initiated at 630, for example, with a base station 610 sending configuration data (e.g., via a PDCCH) to a UE 620. In the continuous mode, NON-HARQ bundled TTI transmissions 632 (with transmission times mapped to VOIP arrival times) may be transmitted from the BS 610 to the UE 620, without the need for HARQ ACKs.

[0053] However, the UE 620 may cause early termination of a packet when in the continuous mode by transmitting an ACK message at 634. As illustrated, while transmission of that packet may be terminated early, the continuous mode may be maintained, for example, with the subsequent transmission of additional NON-HARQ bundled TTI transmissions 632.

[0054] Early termination of a packet may be prompted by a UE, for example, after continuously trying to decode the data, once decoded, the UE can enter into DRX mode to save power. While the Example in Fig. 6 illustrates downlink bundled transmissions only, continuous mode communications may be both uplink and downlink. Further, while the illustrated example shows a UE performing early termination by sending an ACK, a BS 610 may also be capable of terminating continuous mode by sending an ACK to the UE 620. According to certain aspects, a base station may transmit an ACK at a pre-agreed time before the end of each transmission if CRC passes. The UE may detect the ACK and terminate transmissions. This early termination may save battery life for UE and reduce UL interference.

[0055] In addition to early termination via ACK messaging, according to certain aspects, a system may transition between continuous and regular transmissions modes. For example, during active talking time, continuous transmission mode may be used. However, during silence time, a silence identifier (SID) may be transmitted (e.g., at an 160 ms interval). Since this SID is transmitted at a much longer duty cycle, regular transmission mode may be used during the indicated silence time.

[0056] According to certain aspects, time/frequency resources may be partitioned for different users/applications. At any given time, some users may communicate in continuous mode, while others communicate using regular transmission mode. The particular configuration may depend on a variety of factors, such as available resources, Quality of Service (QoS) requirements for different applications, and link budget for each user.

[0057] The particular TTI transmissions bundled and mapped to VOIP arrival times that are allocated to any particular user may also vary. Figs. 7-11 illustrate a plurality of example options for allocating resources for a continuous VOIP transmission.

[0058] Fig. 7 illustrates a first option in which each user may effectively have 20 ms TTI bundling, matched to an exemplary 20ms VOIP packet arrival time. Different users may be multiplexed within each RB through FDM or hybrid FDM/CDM. In cases where there are a lot of users, however, this may result in a heavy processing load and a spike in resource consumption with bundled transmissions to a plurality of users, followed by a relatively long period of little or no activity, which is less than optimal resource utilization.

[0059] Fig. 8 illustrates a second option in which each user has a staggered bundled TTI transmission time. When compared to the option illustrated in FIG. 7, this approach may more evenly distribute signaling as well as processing load. Fig. 9 illustrates a third option in which users have effectively 10 ms TTI bundling, with two groups of users sharing in time. Figs. 10 and 11 illustrate fourth and fifth options in which users have various degrees of bundling (e.g., mixed with 16/4 ms TTI bundles as illustrated in FIG. 10 and mixed with 8/8/4 ms TTI bundles as illustrated in FIG. 11).

[0060] While a VOIP arrival time of every 20ms and a TTI of 1ms may be assumed for illustrative purposes, those skilled in the art will recognize that the TTI bundling and mapping presented herein may be applied with any combination of VOIP arrival times and TTI periods.

[0061] It is understood that the specific order or hierarchy of steps in the processes disclosed is an example of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[0062] Those of skill in the art would understand 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.

[0063] Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments 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.

[0064] The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (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.

[0065] The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In one 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. In one alternative, the processor and the storage medium may reside as discrete components in a user terminal.

[0066] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the appended claims.


Claims

1. A method (500) for communications in a wireless communications system, the method comprising:

receiving (502) configuration signaling from a base station (310) to enter a continuous communications mode; and

processing (504) bundles of transmission time interval, TTI, transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.


 
2. The method (500) of claim 1, wherein the processing comprises:

receiving one or more bundles of TTI transmissions from the base station (310).


 
3. The method (500) of claim 1, further comprising transmitting an acknowledgment (634) to the base station to prompt early termination of a packet sent in the continuous communications mode.
 
4. The method (500) of claim 1, wherein the processing comprises:

transmitting one or more bundles of TTI transmissions to the base station.


 
5. The method (500) of claim 1, further comprising terminating the continuous communications mode in response to receiving an acknowledgement from the base station.
 
6. The method (500) of claim 1, further comprising alternating between the continuous communications mode during an active talk and a regular communications mode during a silence time.
 
7. An apparatus (320) for communications in a wireless communications system, the apparatus comprising:

means for receiving configuration signaling from a base station (310) to enter a continuous communications mode; and

means (324) for processing bundles of transmission time interval, TTI, transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.


 
8. The apparatus (320) of claim 7 or the method (400) of claim 1, wherein a number of TTIs in each bundle corresponds to a time less than a periodic packet arrival time.
 
9. A method (400) for communications in a wireless communications system, the method comprising:

transmitting (402) configuration signaling to at least one user equipment, UE, (320) to enter a continuous communications mode; and

processing (404) bundles of transmission time interval, TTI, transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.


 
10. The method (400) of claim 9 wherein:

the at least one UE (320) comprises a plurality of UEs; and at least one of the following applies:

the processing comprises transmitting bundled TTIs to the different UEs at staggered transmission times,

bundled TTI transmissions for more than one of the UEs are mapped to a same periodic packet arrival time,

bundled transmissions for at least two of the UEs have different numbers of TTI transmissions.


 
11. An apparatus (310) for communications in a wireless communications system, the apparatus comprising:

means for transmitting configuration signaling to at least one user equipment (UE) to enter a continuous communications mode; and

means for processing (314) bundles of transmission time interval, TTI, transmissions having transmission times that are mapped to periodic packet arrival times, wherein the bundled TTI transmissions are processed without acknowledgements to indicate the bundled TTI transmissions have been successfully received.


 
12. The apparatus (310, 320) of claims 7 or 11 or the method (400, 500) of claims 1 or 9, wherein the periodic packet arrival times are for voice-over-internet-protocol, VOIP, packets.
 
13. The apparatus (310, 320) of claims 7 or 11 or the method (400, 500) of claims 1 or 9, wherein the wireless communications system comprises a long term evolution, LTE, system.
 
14. The apparatus (310, 320) of claims 7 or 11 or the method (400, 500) of claims 1 or 9, wherein the signaling is conveyed via a physical downlink control channel, PDCCH.
 
15. A computer-readable medium for communications in a wireless communications system, the computer-readable medium comprising code for carrying out the steps of any of the methods of claims 1 to 6 or 8 to 10 or 12 to 14.
 


Ansprüche

1. Ein Verfahren (500) für Kommunikationen ein einem Drahtloskommunikationssystem, wobei das Verfahren Folgendes aufweist:

Empfangen (502) von Konfigurationssignalisierung von einer Basisstation (310) in einen kontinuierlichen bzw. Dauerkommunikationsmodus einzutreten; und

Verarbeiten (504) von Bündeln von Sendezeitintervall- bzw. TTI-Sendungen (TTI = transmission time interval) mit Sendezeiten, die auf periodische Paketankunftszeiten abgebildet werden, wobei die gebündelten TTI-Sendungen verarbeitet werden, und zwar ohne Bestätigungen zum Anzeigen, dass die gebündelten TTI-Sendungen erfolgreich empfangen worden sind.


 
2. Verfahren (500) nach Anspruch 1, wobei das Verarbeiten Folgendes aufweist:

Empfangen eines oder mehrerer Bündel von TTI-Sendungen von der Basisstation (310).


 
3. Verfahren (500) nach Anspruch 1, das weiter Senden einer Bestätigung (634) an die Basisstation aufweist, um eine frühzeitige Beendigung bzw. einen frühzeitigen Abbruch eines Pakets zu veranlassen, das im Dauerkommunikationsmodus gesendet wird.
 
4. Verfahren (500) nach Anspruch 1, wobei das Verarbeiten weiter Folgendes aufweist:

Senden eines oder mehrerer Bündel von TTI-Sendungen an die Basisstation.


 
5. Verfahren (500) nach Anspruch 1, das weiter Beenden des Dauerkommunikationsmodus ansprechend auf ein Empfangen einer Bestätigung von der Basisstation aufweist.
 
6. Verfahren (500) nach Anspruch 1, das weiter Abwechseln zwischen dem Dauerkommunikationsmodus während eines aktiven Gesprächs und einem regulären Kommunikationsmodus während einer Stillezeit aufweist.
 
7. Eine Vorrichtung (320) für Kommunikationen in einem Drahtloskommunikationssystem, wobei die Vorrichtung Folgendes aufweist:

Mittel zum Empfangen von Konfigurationssignalisierung von einer Basisstation (310) in einen kontinuierlichen bzw. Dauerkommunikationsmodus einzutreten; und

Mittel (324) zum Verarbeiten von Bündeln von Sendezeitintervall- bzw. TTI-Sendungen (TTI = transmission time interval) mit Sendezeiten, die auf periodische Paketankunftszeiten abgebildet werden, wobei die gebündelten TTI-Sendungen verarbeitet werden, und zwar ohne Bestätigungen zum Anzeigen, dass die gebündelten TTI-Sendungen erfolgreich empfangen worden sind.


 
8. Vorrichtung (320) nach Anspruch 7 oder Verfahren (400) nach Anspruch 1, wobei eine Anzahl von TTIs in jedem Bündel einer Zeit entspricht, die geringer ist als eine periodische Paketankunftszeit.
 
9. Ein Verfahren (400) für Kommunikationen in einem Drahtloskommunikationssystem, wobei das Verfahren Folgendes aufweist:

Senden (402) von Konfigurationssignalisierung an wenigstens eine Nutzereinrichtung bzw. UE (UE = user equipment) (320) in einen kontinuierlichen bzw. Dauerkommunikationsmodus einzutreten; und

Verarbeiten (404) von Bündeln von Sendezeitintervall- bzw. TTI-Sendungen (TTI = transmission time interval) mit Sendezeiten, die auf periodische Paketankunftszeiten abgebildet werden, wobei die gebündelten TTI-Sendungen verarbeitet werden, und zwar ohne Bestätigungen zum Anzeigen, dass die gebündelten TTI-Sendungen erfolgreich empfangen worden sind.


 
10. Verfahren (400) nach Anspruch 9, wobei:

die wenigstens eine UE (320) eine Vielzahl von UEs aufweist; und wenigstens eines von Folgendem gilt:

die Verarbeitung weist Senden gebündelter TTIs an unterschiedliche UEs zu gestaffelten Sendezeiten auf,

gebündelte TTI-Sendungen für mehr als eine der UEs werden auf eine gleiche periodische Paketankunftszeit abgebildet,

gebündelte Sendungen für wenigstens zwei der UEs haben unterschiedliche Anzahlen von TTI-Sendungen.


 
11. Vorrichtung (310) für Kommunikationen in einem Drahtloskommunikationssystem, wobei die Vorrichtung Folgendes aufweist:

Mittel zum Senden von Konfigurationssignalisierung an wenigstens eine Nutzereinrichtung bzw. UE (UE = user equipment), in einen kontinuierlichen bzw. Dauerkommunikationsmodus einzutreten; und

Mittel zum Verarbeiten (314) von Bündeln von Sendezeitintervall- bzw. TTI-Sendungen (TTI = transmission time interval) mit Sendezeiten, die auf periodische Paketankunftszeiten abgebildet werden, wobei die gebündelten TTI-Sendungen verarbeitet werden, und zwar ohne Bestätigungen zum Anzeigen, dass die gebündelten TTI-Sendungen erfolgreich empfangen worden sind.


 
12. Vorrichtung (310, 320) nach Ansprüchen 7 oder 11 oder Verfahren (400, 500) nach Ansprüchen 1 oder 9, wobei die periodischen Paketankunftszeiten für Voice-Over-Internet-Protokoll- bzw. VOIP-Pakete vorgesehen sind.
 
13. Vorrichtung (310, 320) nach Anspruch 7 oder 11 oder Verfahren (400, 500) nach Ansprüchen 1 oder 9, wobei das Drahtloskommunikationssystem ein Long-Term-Evolution- bzw. LTE-System aufweist.
 
14. Vorrichtung (310, 320) nach Ansprüchen 7 oder 11 oder Verfahren (400, 500) nach Ansprüchen 1 oder 9, wobei die Signalisierung über einen physikalischen Abwärtsverbindungssteuerkanal bzw. PDCCH (PDCCH = physical downlink control channel) übermittelt wird.
 
15. Ein computerlesbares Medium für Kommunikationen in einem Drahtloskommunikationssystem, wobei das computerlesbare Medium Code zum Durchführen der Schritte nach einem der Verfahren nach Ansprüchen 1 bis 6 oder 8 bis 10 oder 12 bis 14 aufweist.
 


Revendications

1. Procédé (500) pour des communications dans un système de communication sans fil, le procédé comprenant :

recevoir (502) une signalisation de configuration à partir d'une station de base (310) pour passer dans un mode de communication continu ; et

traiter (504) des groupements de transmissions d'intervalles de temps de transmission, TTI, ayant des temps de transmissions qui sont mappés vers des temps d'arrivée de paquets périodiques, les transmissions TTI groupées étant traitées sans accusés de réception pour indiquer que les transmissions TTI groupées ont été reçues avec succès.


 
2. Procédé (500) selon la revendication 1, dans lequel le traitement comprend :

recevoir un ou plusieurs groupements de transmissions TTI à partir de la station de base (310).


 
3. Procédé (500) selon la revendication 1, comprenant en outre l'émission d'un accusé de réception (634) vers la station de base pour inviter à une terminaison avancée d'un paquet envoyé dans le mode de communication continu.
 
4. Procédé (500) selon la revendication 1, dans lequel le traitement comprend :

émettre un ou plusieurs groupements de transmissions TTI vers la station de base.


 
5. Procédé (500) selon la revendication 1, comprenant en outre le fait de mettre fin au mode de communication continu en réponse à la réception d'un accusé de réception provenant de la station de base.
 
6. Procédé (500) selon la revendication 1, comprenant en outre le fait d'alterner entre le mode de communication continu pendant un temps de parole active et un mode de communication normal pendant un temps de silence.
 
7. Dispositif (320) pour des communications dans un système de communication sans fil, le dispositif comprenant :

des moyens pour recevoir une signalisation de configuration à partir d'une station de base (310) pour passer dans un mode de communication continu ; et

des moyens (324) pour traiter des groupements de transmissions d'intervalles de temps de transmission, TTI, ayant des temps de transmissions qui sont mappés vers des temps d'arrivée de paquets périodiques, les transmissions TTI groupées étant traitées sans accusé de réception pour indiquer que les transmissions TTI groupées ont été reçues avec succès.


 
8. Dispositif (320) selon la revendication 7 ou procédé (400) selon la revendication 1, dans lequel un certain nombre de TTI dans chaque groupement correspondent à un temps inférieur à un temps d'arrivée de paquet périodique.
 
9. Procédé (400) pour des communications dans un système de communication sans fil, le procédé comprenant :

émettre (402) une signalisation de configuration vers au moins un équipement d'utilisateur, UE, (320) pour passer dans un mode de communication continu ; et

traiter (404) des groupements de transmissions d'intervalles de temps de transmission, TTI, ayant des temps de transmission qui sont mappés vers des temps d'arrivée de paquets périodiques, les transmissions TTI groupées étant traitées sans accusés de réception pour indiquer que les transmissions TTI groupées ont été reçues avec succès.


 
10. Procédé (400) selon la revendication 9, dans lequel :

ledit au moins un UE (320) comprend une pluralité d'UE ; et au moins l'un des cas suivants s'applique :

le traitement comprend la transmission de TTI groupés vers les différents UE à des instants de transmission échelonnés,

des transmissions TTI groupées pour plus qu'un seul des UE sont mappées vers un même temps d'arrivée de paquet périodique,

des transmissions groupées pour au moins deux des UE ont des nombres de transmissions TTI différents.


 
11. Dispositif (310) pour des communications dans un système de communication sans fil, le dispositif comprenant :

des moyens pour émettre une signalisation de configuration vers au moins un équipement d'utilisateur (UE) pour passer dans un mode de communication continu ; et

des moyens pour traiter (314) des groupements de transmissions d'intervalles de temps de transmission, TTI, ayant des temps de transmission qui sont mappés vers des temps d'arrivée de paquets périodiques, les transmissions TTI groupées étant traitées sans accusés de réception pour indiquer que les transmissions TTI groupées ont été reçues avec succès.


 
12. Dispositif (310, 320) selon les revendications 7 ou 11 ou procédé (400, 500) selon les revendications 1 ou 9, dans lequel les temps d'arrivée de paquets périodiques sont pour des paquets de voix sur le protocole Internet, VOIP.
 
13. Dispositif (310, 320) selon les revendications 7 ou 11 ou procédé (400, 500) selon les revendications 1 ou 9, dans lequel le système de communication sans fil comprend un système d'évolution à long terme, LTE.
 
14. Dispositif (310, 320) selon les revendications 7 ou 11 ou procédé (400, 500) selon les revendications 1 ou 9, dans lequel la signalisation est transportée par l'intermédiaire d'un canal physique de commande en liaison descendante, PDCCH.
 
15. Support lisible par un ordinateur pour des communications dans un système de communications sans fil, le support lisible par un ordinateur comprenant du code pour réaliser les étapes de l'un quelconque des procédés des revendications 1 à 6 ou 8 à 10 ou 12 à 14.
 




Drawing



























REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description




Non-patent literature cited in the description