CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to U.S. Patent Application Serial Number
12/552,513, entitled "SYSTEMS AND METHODS FOR MANAGING WIRELESS COMMUNICATION LINKS FOR HEARING
ASSISTANCE DEVICES", filed September 2, 2009, which claims the benefit under 35 U.S.C.
119(e) of U.S. Provisional Patent Application Serial Number
61/094,021, filed September 3, 2008, which is incorporated herein by reference in its entirety.
[0002] The present application is related to U.S. Patent Application Serial Number
13/843,852, entitled "METHOD AND APPARATUS TO DISPLAY INTERFERENCE FOR A WIRELESS HEARING ASSISTANCE
DEVICE PROGRAMMER", filed on even date herewith (Attorney Docket Number 899.365US1),
and U.S. Patent Application Serial Number
61/801,152, entitled "WIRELESS ENVIRONMENT INTERFERENCE DIAGNOSTIC HEARING ASSISTANCE DEVICE
SYSTEM", filed on even date herewith (Attorney Docket Number 899.366PRV), which are
incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0003] This application relates generally to wireless networks and, more particularly, to
systems, devices and methods for managing wireless communication links for hearing
assistance devices including those using Bluetooth Low Energy (BLE) communication
technology.
BACKGROUND
[0004] Radio waves are electromagnetic waves that can be used in wireless communication.
The frequencies of these waves serve as physical communication channels. The radio
frequency (RF) spectrum has a finite range of frequencies, and thus a limited number
of channels. In the United States, for example, the Federal Communications Commission
(FCC) decides how the spectrum is allocated and what bands are used for what purpose.
[0005] Communication signals on the same channel interfere, assuming the strengths of the
signals are non-negligible due to transmission power and distance. Also, communication
signals on adjacent channels may interfere with communications on the desired channel
because of inadequate filtering, tuning or frequency control. Adjacent channel interference
can increase with an increase in signal power in adjacent channels.
[0006] Most countries of the world have allocated certain frequency spectrums for commercial
use as "unlicensed" wireless bands. For example, the FCC has designated license-free
bandwidth segments for industrial, scientific and medical (ISM) uses. Various commercial
applications use this unlicensed bandwidth for short range wireless communication.
[0007] Channels are not allocated within the license-free band. Commercial devices designed
to operate in the license-free band are constrained to transmit using a relatively
low power, which allows more commercial devices to use the unlicensed frequency bands
by increasing the reuse of a frequency. Spread spectrum systems mitigate interference
by spreading their information over a much larger bandwidth than the information requires.
This has the advantage of spreading any narrowband interference encountered within
the channel over a large bandwidth which can then be integrated out by the receiver.
The transmitter and receiver coordinate and manage the spreading sequences. This adds
complexity and power to spread the signal using either fast frequency hopping or direct
sequence phase manipulation. This added complexity and power may prevent these schemes
from being used in ultra-low power communications systems.
SUMMARY
[0008] Various system embodiments comprise a plurality of devices configured to wirelessly
communicate with each other. The plurality of devices includes a battery-operated
hearing aid configured to communicate with another device using Bluetooth Low Energy
(BLE) wireless communication technology. A BLE tester is configured to test the hearing
aid for the performance of BLE wireless communication via a wireless link. One embodiment
uses a wireless test mode as a diagnostic tool for analyzing the wireless communication
environment, such as when the communication with the hearing aid is interfered in
a noisy environment.
[0009] In one embodiment, a system for managing wireless communication includes a first
device and a second device. The first device includes a BLE wireless communication
circuit configured to receive and transmit data using BLE wireless communication technology.
The second device includes a BLE tester configured to wirelessly communicate with
the first device and test the BLE wireless communication circuit according to a wireless
test mode in response to a test command associated with the wireless test mode. The
second device includes an analysis initiator configured to generate the test command
in response to a signal requesting a diagnostic analysis of an environment of the
wireless communication. In one embodiment, at least one of the first device and the
second device is a hearing aid.
[0010] In one embodiment, a method for wirelessly communicating with a hearing aid includes
performing wireless communication with the hearing aid using BLE wireless communication
technology and performing a diagnostic analysis of an environment of the wireless
communication. The performance of the diagnostic analysis includes establishing a
wireless link between the hearing aid and a BLE tester, testing the hearing aid for
quality of data transmission associated with the wireless link according to a specified
wireless test mode, and producing information indicative of one or more characteristics
of the environment of the wireless communication.
[0011] This Summary is an overview of some of the teachings of the present application and
not intended to be an exclusive or exhaustive treatment of the present subject matter.
Further details about the present subject matter are found in the detailed description
and appended claims. The scope of the present invention is defined by the appended
claims and their legal equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012]
FIGS. 1A-1D illustrate a wireless link between various embodiments of a hearing assistance
device and a communicator.
FIG. 2A-2E illustrate a communicator operably connected to different devices, according
to various embodiments.
FIGS. 3A-3E illustrate a communicator integrated within different devices, according
to various embodiments.
FIG. 4 illustrates an embodiment of a wireless system with a wireless audio controller
(WAC) and at least one hearing assistance device.
FIG. 5 illustrates various wireless communication environment(s) with a hearing aid
device, according to various embodiments of the present subject matter.
FIG. 6 illustrates a wireless communication network within a multi-office environment
with multiple programmers and hearing aids.
FIG. 7 illustrates a block diagram of a hearing aid embodiment.
FIG. 8 illustrates a block diagram of the communicator, such as a programmer.
FIG. 9 illustrates a wireless communication system embodiment.
FIGS. 10A-10B illustrate device embodiments with primary and secondary receivers.
FIGS. 11-13 illustrate embodiments of methods for managing wireless communication
links.
FIG. 14 illustrates a state diagram of an embodiment of a process performed by a station
to maintain link quality.
FIG. 15 illustrates a block diagram of Bluetooth Low Energy (BLE) device embodiment.
FIG. 16 illustrates a block diagram of BLE hearing aid embodiment.
FIG. 17 illustrates a block diagram of BLE device embodiment including a BLE tester.
FIG. 18 illustrates an embodiment of a method for managing a BLE wireless communication
link.
FIG. 19 illustrates an embodiment of a method for performing a diagnostic analysis
of a BLE wireless communication link.
DETAILED DESCRIPTION
[0013] The following detailed description of the present subject matter refers to subject
matter in the accompanying drawings which show, by way of illustration, specific aspects
and embodiments in which the present subject matter may be practiced. These embodiments
are described in sufficient detail to enable those skilled in the art to practice
the present subject matter. References to "an", "one", or "various" embodiments in
this disclosure are not necessarily to the same embodiment, and such references contemplate
more than one embodiment. The following detailed description is demonstrative and
not to be taken in a limiting sense. The scope of the present subject matter is defined
by the appended claims, along with the full scope of legal equivalents to which such
claims are entitled.
[0014] FIGS. 1A-1D illustrate a wireless link between various embodiments of a hearing assistance
device and a communicator. FIG. 1A illustrates a wireless communication link 100A
between the hearing assistance device 101A and the communicator 102A. The communication
link is used to communicate information. Examples of information include audio data
or other data, commands, and programming instructions. In RF communication, the communication
link uses a transmission frequency to establish the link in a communication channel.
Examples of hearing assistance devices include both prescription devices and non-prescription
devices. Examples of hearing assistance devices include hearing aids, headphones,
assisted listening devices, earbuds, and the like. The communicator represents a device
that communicates information to the hearing assistance device over the wireless communication
link.
[0015] FIG. 1B illustrates the system of FIG 1A, where the communicator includes a link
quality management device. As will be described below, the link quality management
device 103B assesses the quality of the communication link 100B, and controls the
adjustments to the communication over the link. Some embodiments, the communication
adjustments are made by the communicator 102B. Some embodiments send a command from
the communicator 102B to the hearing assistance device 101B instructing the hearing
assistance device to take an action in an effort to improve the quality of the wireless
communication link. In some embodiments, when it is determined that an action should
be taken to adjust communication and improve the link quality, the communicator makes
an adjustment and sends a command to the hearing assistance device instructing the
hearing assistance device to take an action to adjust communication and improve the
link quality.
[0016] FIG. 1C illustrates the system of FIG 1A, where the hearing assistance device includes
a link quality management device. As will be described below, the link quality management
device 104C assesses the quality of the communication link 100C, and controls the
adjustments to the communication over the link. Some embodiments, the communication
adjustments are made by the hearing assistance device 101C. Some embodiments send
a command from the hearing assistance device 101C to the communicator 102C instructing
the communicator to take an action in an effort to improve the quality of the wireless
communication link. In some embodiments, when it is determined that an action should
be taken to improve the link quality, the hearing assistance device makes an adjustment
and sends a command to the communicator instructing the communicator to take an action
to adjust communication and improve the link quality. In some embodiments, the hearing
assistance device sends communications statistics such as CRC errors, SNR levels,
FEC statistics, etc. to the host communications device so that it can take action
to improve the link quality.
[0017] FIG. 1D illustrates the system of FIG 1A, where both the hearing assistance device
and the communicator include a link quality management device. As will be described
below, the link quality management devices 103D and 104D assesses the quality of the
communication link 100D, and controls the adjustments to the communication over the
link. According to various embodiments, both link quality management devices monitor
the link quality the same way, or the link quality management devices monitor different
aspects of the link quality (e.g. distribute the link quality assessment). In some
embodiments, only one of the devices operates its link quality management device to
monitor link quality. The choice between the devices 103D and 104D can be made during
communication initialization or can be preprogrammed. According to various embodiments,
when it is determined that an action should be taken to improve the link quality,
one or both of the devices 101D and 102D take an action to adjust communication and
improve the link quality.
[0018] FIG. 2A-2E illustrate a communicator operably connected to different devices, according
to various embodiments. The illustrated communicator 202 is a device configured to
be connected to another device as a peripheral device. For example, the device and
the peripheral communicator can be connected via Wireless communication such as Bluetooth
or WiFi or wired technology such as USB or firewire. The peripheral communicator can
be connected to a variety of devices, such as to a programmer as illustrated in FIG.
2A, a hearing assistance device as illustrated in FIG. 2B, an assisted listening device
as illustrated in FIG. 2C, a streaming audio device as illustrated in FIG. 2D, and
a wireless audio controller (WAC) as illustrated in FIG. 2E.
[0019] FIGS. 3A-3E illustrate a communicator integrated within different devices, according
to various embodiments. The illustrated communicator 302 is a device configured to
be integrated with or built within another device as a peripheral device. For example,
the communicator can be an expansion card connected within a computer chassis. The
communicator can be integrated with or built within a variety of devices, such as
to a programmer as illustrated in FIG. 3A, a hearing assistance device as illustrated
in FIG. 3B, an assisted listening device as illustrated in FIG. 3C, a streaming audio
device as illustrated in FIG. 3D, and a wireless audio controller (WAC) as illustrated
in FIG. 3E.
[0020] FIG. 4 illustrates an embodiment of a wireless system with a wireless audio controller
(WAC) and at least one hearing assistance device.
US 2006/0274747, entitled: COMMUNICATION SYSTEM FOR WIRELESS DEVICES, and
US 11/619541, entitled: WIRELESS SYSTEM FOR HEARING COMMUNICATION DEVICE PROVIDING WIRELESS STEREO
RECEPTION MODES, both of which are incorporated herein in their entirety, and include
examples of WACs. The illustrated WAC 405 includes an I/O port 406 to a network 407
(e.g., Internet, LAN, WAN, WILAN, Bluetooth, Cellular, etc.) through which data (e.g.,
compressed audio data) is communicated to the WAC. The illustrated WAC also includes
at least one I/O port configured for use to wirelessly communicate with at least one
hearing assistance device. The illustrated WAC embodiment includes two I/O ports 408
and 409 configured to be used to communicate with a hearing assistance device. For
example, a first port can communicate a left channel and a second port can communicate
a right channel to provide a wearer of the hearing aid devices with a stereo sound.
If the link quality of one of the channels is determined to be undesirably low, the
illustrated WAC is able to send the same signal to both hearing assistance devices.
This signal can represent a monophonic signal to be presented to both of the hearing
assistance devices, or can represent one channel of a stereophonic signal to be presented
to both of the hearing assistance devices. The connection between the WAC 406 and
the network 407 can be wireless, wired, or a hybrid of wired and wireless. Wireless
communications can include standard or nonstandard communications. Some examples of
standard wireless communications include link protocols including, but not limited
to, Bluetooth™, IEEE 802.11(wireless LANs), 802.15(WPANs), 802.16(WiMAX), 802.20 mobile
wireless, cellular protocols including, but not limited to CDMA and GSM, ZigBee, and
ultra-wideband (UWB) technologies. Such protocols support radio frequency communications
and some support infrared communications. It is possible that other forms of wireless
communications can be used such as ultrasonic, optical, and others. It is understood
that the standards which can be used include past and present standards. It is also
contemplated that future versions of these standards and new future standards may
be employed without departing from the scope of the present subject matter. Wired
communications include, but are not limited to, one or more mono or stereo connections
or digital connections having link protocols including, but not limited to IEEE 802.3
(Ethernet), 802.4, 802.5, USB, ATM, Fibre-channel, Firewire or 1394, InfiniBand, or
a native streaming interface. Such connections include all past and present link protocols.
It is also contemplated that future versions of these protocols and new future standards
may be employed without departing from the scope of the present subject matter.
[0021] FIG. 5 illustrates various wireless communication environment(s) with a hearing aid
device, according to various embodiments of the present subject matter. The illustrated
hearing aid device 510 is an in-the-ear hearing aid that is positioned completely
in the ear canal 511. The present subject matter is not so limited, however. In addition
to the illustrated in-the-ear style, the features of the present subject matter can
be used in other styles of hearing assistance devices, including half-shell, in-the-canal,
behind-the-ear, over-the-ear, eyeglass mount, implants, and body worn hearing aids,
and further can be used in noise-protection earphones, headphones, and the like.
[0022] Referring again to FIG. 5, a wireless communication system in the hearing aid is
configured to communicate with one or more devices. In various embodiments, the hearing
aid uses RF wireless communication to communicate with an external programmer 512.
The programmer is able to adjust the hearing aid settings such as mode, volume and
the like, to download a complete hearing aid program, and to receive data from the
hearing aid for data logging, diagnostics, reporting and the like. In various embodiments,
the hearing aid wirelessly communicates with an assisted listening system 513 to receive
an audio signal, or a device 514 that provides encoded and compressed audio, or a
remote control device 515, or another hearing aid 516, or various combinations thereof.
[0023] One challenging environment for hearing aid wireless communication involves a multi-office
environment where several programmers may be within range of one another and attempt
to discover nodes (e.g., hearing aids) simultaneously. In addition many nodes may
be within range of each programmer. Furthermore, the multi-office environment may
include other wireless services and/or otherwise devices that emit electromagnetic
radiation that may adversely affect the desired wireless communication.
[0024] FIG. 6 illustrates a wireless communication network within a multi-office environment
with multiple programmers and hearing aids. Any of the programmers 612 are capable
of discovering and communicating with hearing aids 610. Further, the programmers 612
can be wirelessly networked together, such as illustrated by the wireless network
617. Additionally, some hearing aids (e.g. left/right hearing aids for a patient)
can be designed to wireless communicate with each other in addition to the programmers
612 or other communicators.
[0025] Some hearing aid embodiments incorporate a scanning feature to reduce the probability
of interference. The probability that interference is on multiple channels simultaneously
is significantly less, since the conditional probabilities for independent events
are multiplied together for the overall probability that both channels will simultaneously
experience interference. Interference can increase the duty cycle of the receiver
since the detection of energy on a channel above a Receive Signal Strength Indicator
(RSSI) threshold causes the receiver to stay awake. Thus, interference can adversely
impact the battery life of the hearing aid. Some embodiments use a wake timer that,
if the receiver is awake longer than the sleep cycle without receiving a valid packet,
causes the receiver to go into a deep sleep mode with a longer sleep cycle until the
interference goes away.
[0026] A system, such as the one illustrated in FIG. 6, performs a process to discover the
nodes in operational proximity. Any number of channels can be assigned as discovery
channels. The use of two or more discovery channels considerably increases the odds
of successful links in comparison to a single discovery channel as the single channel
may already be in use. These channels are reserved for node discovery of hearing aids
by programmers. Programmers pick a desirable discovery channel based on a link quality
assessment (LQA). Hearing aids scan the discovery channel frequencies prior to establishing
a programming link. During discovery, programmers ping for nodes using a broadcast
discovery message that is sent out at random intervals. The node is registered with
the programmer if an acknowledgement is received by the programmer. Hearing aids register
with all programmers in discovery mode within range of the hearing aid, and associate
with programmers after being discovered and selected via the programmer's user interface.
Once nodes are discovered, the user is notified using the user display of the hearing
aids that are within range. The user then can select the nodes with which to establish
a link.
[0027] Various programmer embodiments use a LQA table which is updated by scanning each
available channel and is used by the programmer to determine a desirable channel,
on which to establish a wireless communication session, among the available channels.
The programmer sends a frequency change message to each hearing instrument. This message
is acknowledged by the hearing aid. Normal data transfer to and from the hearing instrument
can begin once the link has been established on the desired channel. Some programmer
embodiments perform intermittent (e.g., periodic) maintenance throughout the wireless
communication session. In some embodiments, the host communications device sends a
maintenance message that contains the next available channel in case the link is lost
due to interference as well as a transmit power control word. The channel maintenance
response from the hearing instrument contains several communications metrics such
as the number of successful packets received since the last maintenance response and
the number of packets containing errors. This information is used by the programmer
to determine the downlink quality and the uplink quality. The programmer is able to
determine the downlink quality by comparing the number of no acknowledgments with
the number of messages received by the hearing instrument. In addition to statistics
collected during maintenance, some programmer embodiments monitor the RSSI of the
nodes on each packet received. Some embodiments maintain this signal strength as a
moving average in time. The signal strength can be used to adjust the power control
of the uplink signal from the nodes. Adjustments can be made during maintenance messages.
The links can operate on the fringe of link margin. However, if there is sufficient
link margin, various embodiments allow for upstream power reduction (transmission
from remote nodes/hearing aids to the host communications device) to save power in
the remote nodes. As is discussed below, there are a number of ways to assess the
link quality of RF communication links and a number of ways to adjust the RF communication
based on the assessed link quality.
[0028] FIG. 7 illustrates a block diagram of a hearing aid embodiment. The illustrated hearing
aid 710 includes a microphone system 718, a signal processing circuit 719 which may
be incorporated as part of a controller, and a speaker 720 referred to as a hearing
aid receiver. The microphone system 718 transforms the acoustic energy 721 of sound
from an acoustic source 722 into a signal representative of the sound. The signal
processing circuit 719 receives the signal from the microphone system 718, and is
designed (e.g., programmed) to appropriately adjust the signal to compensate for the
hearing impairment of the wearer of the hearing aid. The signal processing circuit
719 outputs a processed signal to the hearing aid receiver 720, which converts the
processed electrical signal into a sound perceived by the wearer. The illustrated
hearing aid embodiment also includes a wireless communication circuit 723 configured
to transmit and/or receive wireless signals. The wireless communication circuit may
include a receiver, a transmitter, or a transceiver. The signal processing circuit
719 (or controller) controls the wireless communication circuit 723 to control the
wireless communication with other devices.
[0029] FIG. 8 illustrates a block diagram of the host wireless communicator, such as a programmer.
The illustrated communicator includes a controller 824 and a wireless communication
circuit 825 configured to transmit and/or receive wireless signals. The wireless communication
circuit may include a receiver, a transmitter, or a transceiver. The controller 824
controls the wireless communication circuit 825 to control the wireless communication
with other devices. The station can include other elements, such as various input/output
devices like a display monitor, keyboard and mouse.
[0030] FIG. 9 illustrates a wireless communication system embodiment. The illustrated system
includes a number of devices configured to wirelessly communicate with at least one
other device in the system. The devices in the system illustrated in FIG. 9 include
a host communicator such as illustrated in FIG. 8, and further include first 910R
and second 910L hearing aids, such as illustrated in FIG. 7 and as may be simultaneously
worn to assist hearing in a person's right and left ears. As illustrated by the dotted
lines in FIG. 9, the communicator is configured to wireless communicate with both
hearing aids, the first hearing aid is configured to wirelessly communicate with the
second hearing aid and the communicator, and the second hearing aid is configured
to wirelessly communicate with the first hearing aid and the communicator. The communication
signals may include data and/or audio. Examples of data include programming instructions,
device diagnostics, and link quality information. Examples of audio include digital
audio or compressed digital audio.
[0031] FIGS. 10A-10B illustrate device embodiments with primary and secondary receivers.
FIG. 10A illustrates a device embodiment with an antenna 1026, and a primary receiver
1027 and a secondary receiver 1028 connected to the antenna. The antenna can include
spatially-diverse antennas, an antenna with diverse polarities, or spatially-diverse
antennas with diverse polarities. The primary receiver 1027 receives a data communication
using the antenna, and the secondary receiver 1028 scans other possible communication
channels to assess the link quality of these other channels in anticipating of switching
the channel used by the primary receiver. In the illustrated embodiment, the secondary
receiver 1028 provides a list of next best channels, and provides the primary receiver
with the next best alternate channel. The primary receiver 1027 receives the data
communication through a channel, monitors channel metrics indicative of channel quality
for the channel used to receive the data. Examples of channel metrics include bit
error rate (BER), packet error rate (PER), cyclic redundancy check (CRC) errors, forward
error correction (FEC) errors, signal to noise ratio (SNR), and the number of retransmissions.
[0032] FIG. 10B provides a more detailed illustration of a device embodiment with an antenna
1026, and primary and secondary receivers. The illustrated antenna 1026 is a spatially
diverse antenna and/or has diverse polarities. A received signal passes through a
low noise amplifier (LNA) 1029, and then passes to both a primary and a secondary
receiver.
[0033] The primary receiver includes a local oscillator (LO) 1030 which is programmed to
oscillate at a frequency necessary for communications. A mixer 1031 multiplies the
signal from the LNA with the signal from the LO 1030, and outputs the resulting modulated
signal to a bandpass filter 1032. A demodulator 1033 demodulates the modulated signal
to provide the data from the signal to a gate 1034 and to a correlator 1035. The modulated
signal is also presented to a Receive Signal Strength Indicator (RSSI) module 1036
that compares the strength of the received signal to a threshold and outputs the signal
level to the correlator 1035. The correlator controls the timing of the received signal
level and the received data to allow the data to pass through the gate when the signal
level is above the RSSI threshold and when a correlation word is received. A multiplexer
1037 outputs a data signal level when data is received (Y=1) and outputs a noise signal
level when data is not received (Y=0), which are used to determine a signal to noise
ratio (SNR). The SNR can be used to change the diverse antenna. For example, an antenna
currently being used can be exchanged for a spatially-diverse antenna and/or a polarity
of an antenna can be changed. The SNR measurement can be used to switch to an alternate
channel. If the SNR is less than a threshold, the next best alternate channel is used
for the data transmission. The data passed through the gate can be presented to an
error rate detector 1038 which can determine the error rate on a bit or packet basis,
and can be presented to a module 1039 to extract channel maintenance messages embedded
in the data. Examples of channel maintenance messages include the number of good received
packets, the number of CRC errors, the number of FEC errors, and the number of retransmissions
sent by a node. This information can also be used to determine when to change the
diverse antenna and/or change channels.
[0034] The secondary receiver includes a scanning local oscillator (LO) 1040 that scans
frequencies corresponding to available channels. A mixer 1041 multiplies the signal
from the LNA with the signal from the scanning LO 1040, and outputs the resulting
modulated signal to a bandpass filter 1042. A Receive Signal Strength Indicator (RSSI)
module 1043 measures the strength of the received signal and outputs the signal level
to quality measurement module 1044 configured to monitor the quality of potential
communication channels based on noise levels. An LQA ranking module 1045 ranks the
available channels based on their link quality (e.g., channels with lower noise rank
higher than channels with higher noise). A table 1046 is used to store entries with
frequencies of available channels, along with a quality rank for each entry. The table
can be used to provide the highest ranking channel as the next available channel to
replace the current working communication frequency in the primary receiver. The channel
quality metric is formed using both a peak detector and an RMS detector.
[0035] FIG. 11 illustrates a method for managing wireless communication links according
to various embodiments of the present subject matter. The link quality of a wireless
communication link is assessed at 1147, and the wireless communication is adjusted
at 1148 based on the assessed link quality.
[0036] FIG. 12 illustrates a method for managing wireless communication links according
to various embodiments of the present subject matter. A first link quality metric
is determined at 1249; and at 1250, communication is adjusted based on the first link
quality metric. A second link quality metric is determined at 1251; and at 1252, communication
is adjusted based on the second link quality metric. Some embodiments continue this
determination and adjustment to an nth time, such that an nth link quality metric
is determined at 1253; and at 1254, communication is adjusted based on the nth link
quality metric. The determination of a link quality metric (e.g. 1249, 1251, or 1253)
can be based on an assessment of one or more aspects of the communication link, and
the assessment(s) of the aspect(s) of the communication link can be performed simultaneously
or according to various sequences. By way of example, and not limitation, an embodiment
determines a first link quality metric by assessing the signal strength on the channel,
a second link quality metric by assessing a signal to noise ratio, and a third link
quality metric by assessing the combination of signal to noise ratio, error rate,
and a number of retransmissions being required for sending a packet.
[0037] FIG. 13 illustrates a method for managing wireless communication links according
to various embodiments of the present subject matter. The link quality of a wireless
communication link is assessed at 1347, and the wireless communication is adjusted
at 1348 based on the assessed link quality. According to various embodiments, the
link quality of a wireless communication link is assessed using a signal to noise
ratio for a link 1355, a bit error rate for the link 1356, a number of retransmissions
for a link over a period of time 1357, or various combinations thereof. The figure
illustrates some examples of ways to assess the current communication channel's link
quality. Any one or any combination of assessments may be performed simultaneously
or in various sequences to provide a link quality assessment. LQA is discussed in
further detail below. According to various embodiments, adjusting wireless communication
includes adjusting transmission power 1358, adjusting a symbol rate of transmission
1359, adjusting a Receive Signal Strength Indicator (RSSI) threshold 1360, adjusting
a packet length 1361, adjusting selection of a diverse antenna 1362 (e.g. spatially-diverse
and/or diverse in polarity), adjusting a transmission frequency (channel hopping)
1363, and adjusting receiver gain based on RF environment detected across all or a
subset of available channels 1364. It is understood that in various embodiments, adjustments
may be done outside of during channel maintenance times. For example, in various embodiments
a channel change may be performed when a packet is not acknowledged for a number of
retries, which may be performed outside of a maintenance interval. Other adjustments
are possible and those provided herein are not intended to be exhaustive or limiting.
Link Quality Assessment (LQA)
[0038] Battery-powered remote devices that function as hearing assistance devices (e.g.,
hearing aids) transmit with limited power, such that, as seen by the receiver of the
transmission (e.g., communicator or other hearing aids), the transmission is near
the noise floor of the occupied channel. Communication with low power devices, having
little power available for transmit, will have minimal link margin. A high data throughput
can be achieved using a low power RF link when the link is of good quality. However,
multi-path fading, interference, body and head shadowing, and increased range potentially
impair the link.
[0039] An assessment of link quality for a wireless communication channel can be made by
assessing noise in the channel, or signal strength in the channel, or a signal to
noise ratio for the channel, or a bit error rate, or a packet error rate, or the number
of retransmissions, or various combinations thereof.
Wireless Communication Adjustments Based On LQA
[0040] The present subject matter uses LQA information, also referred to herein as channel
metrics, for wireless communication channels to manage and make adjustments to the
wireless communication.
Power
[0041] Various embodiments of a wireless communication system with hearing aid nodes use
variable power levels for the transceiver based on channel quality metrics. Some embodiments
use link quality metrics to control transmit RF power of devices using the link for
communicating to, from or between hearing aids. Some embodiments use link quality
metrics to control receiver input power consumption (e.g., receiver gain vs. linearity)
for devices communicating to, from, or between hearing aids. Some embodiments automatically
control gain of the receiver based on the RF environment (see, for example,
US 2007/0110193 entitled Automatic Gain Control With Out Of Band Blocking Signal Compensation, which
is incorporated by reference in its entirety).
[0042] A decision metric is used to change power levels used on a wireless communications
channel. Various embodiments employ adaptive transmit and receive power levels based
on several channel metrics to improve power consumption and the link margin of the
overall system. At any time during the communication session, the system may change
transmit power levels or reduce the receiver power based on channel metrics used to
assess link quality.
[0043] If the link from a station to a hearing aid (downstream link) is good, the station
can lower its output power based on downstream link quality metrics in order to reduce
its power consumption and potential interference with other such devices within range.
The hearing aid may decide to lower its receiver gain and or linearity to conserve
power when the downlink from the station is above an acceptable level of performance.
If the link from the hearing aid to the station is good, the station may command the
hearing aid to lower its transmission output power to improve the overall battery
life of the hearing aid. If the link is poor, power may be increased to the extent
permitted by power constraints for the device and system design to improve link margin.
[0044] If it is determined that the channel has a poor link quality, various embodiments
increase RF power to maintain the link while maintaining the overall information throughput,
various embodiments reduce the gain and linearity of the hearing aid's receiver to
reduce the overall power consumption of the hearing aid when the link is of sufficient
quality to warrant a reduction in receive performance.
Symbol Transmission Rates
[0045] Various embodiments of a wireless communication system with hearing aid nodes use
various symbol rates based on channel quality metrics. A decision metric is used to
change symbol rates a wireless communications channel employed for use with a hearing
communication device. Various embodiments employ lower/higher symbol rates based on
one or more channel metrics to improve the link margin of the overall system. At any
time during a communication session, the system may change symbol rates based on channel
metrics used to assess link quality.
[0046] Several methods for changing the symbol rate may be employed. For example, some embodiments
employ a binary set of frequency shift key (FSK) symbols that alternate at the symbol
rate. These symbols which control the symbol rate can be contained in the preamble,
the sync word, or the message body. The receiver can then adapt its data recovery
and pre and post detection filtering based on the symbol rate of the preamble, the
sync word or the message body. If it is determined that the channel has a poor link
quality, various embodiments reduce the symbol rate to maintain the link while lowering
the overall throughput. If the channel's link quality is good or has improved, the
symbol rate will increase to the extent permitted for the link quality.
Receive Signal Strength Indicator (RSSI) Threshold
[0047] A packet receive state machine in a receiver uses a RSSI threshold to determine the
start of a packet transmission. Various embodiments of a wireless communication system
with hearing aid nodes use an adaptive RSSI threshold. A decision metric is used to
change the RSSI threshold on the packet receive state machine used on a wireless communications
channel employed for use with a hearing communication device. The receiver state machine
employs an RSSI threshold detector, a carrier recovery circuit, a timing recovery
circuit, and a sync word correlator to determine the start of a packet reception.
[0048] Because the power-limited hearing aid transmits near the noise floor, the receiver
(e.g., station) sets the RSSI threshold very close to the noise floor of the receiver
but sufficiently high to avoid false detection on noise. If the receiver falsely identifies
noise as a communication signal, the noise starts the receiver state machine which
may make incorrect decisions on carrier and timing recovery (false detects) which
will then prevent the actual packet from being optimally decoded by the receiver.
These false detects can be avoided by setting the RSSI threshold appropriately above
the noise floor of the receiver.
[0049] Since the system uses an unlicensed band, various sources of interference may appear
from time to time on the channel of interest. These interferers cause the noise floor
of the channel to vary with time. To account for this, various embodiments use an
adaptive RSSI threshold to increase link margin (if available) in receiving a packet
from a low powered remote hearing instrument. Various embodiments adjust this threshold
more or less continuously and set the threshold during periods of non-packet activity
on the channel, usually prior to or just after a packet is received. Some embodiments
measure RSSI on a per packet basis and set the threshold as high as practical based
on the quality of the link using RSSI values attained during and between packet receptions.
[0050] If at any time during the session, the system may change the RSSI threshold based
on based on channel metrics used to assess link quality. In addition to determining
if the error rate falls below an acceptable level or the number of transmissions rises
above an acceptable level, the RSSI can be deemed unacceptable for reliable communication
based on the level of signal strength as measured in between packet receptions (quiet
times), based on the level of signal strength as measured during packet reception,
or where the signal to noise ratio has improved or been reduced, a combination of
signal strength as measured in between packet receptions (quiet times) and as measured
during packet reception.
[0051] For example, a station or programmer embodiment performs a channel maintenance algorithm,
and adjusts the RSSI threshold for receiving a packet based on the number of retransmissions
attempts and the number of checksum errors counted since the last channel maintenance
window. If the number of errors and retry attempts indicate a packet error rate higher
than 12%, for example, the programmer monitors the channel's noise floor to adjust
the RSSI threshold.
Packet Length
[0052] Various embodiments of a wireless communication system with hearing aid nodes use
various packet lengths based on channel quality metrics. A decision metric is used
to change packet lengths a wireless communications channel employs for use with a
hearing communication device. Various embodiments employ shorter/longer packet lengths
based on one or more channel metrics to improve the link margin of the overall system.
At any time during a communication session, the system may change packet lengths based
on channel metrics used to assess link quality. If it is determined that the channel
has a poor link quality, various embodiments shorten the packet length. If the channel's
link quality is good or has improved, various embodiments lengthen the packet length
to the extent permitted for the link quality.
Diverse (Spatial/Polarity) Antenna
[0053] Various embodiments of a wireless communication system with hearing aid nodes use
diverse antenna(s), and change the diverse antenna(s) based on channel quality metrics.
For spatially-diverse antennas, the current antenna can be switched with another antenna.
For an antenna with diverse polarities, the polarity of the antenna can be switched.
A decision metric is used to change/combine antennas used on a wireless communications
channel employed for use with a hearing communication device.
[0054] In an indoor environment there are many sources of radio frequency reflections that
cause multi-path signal arrivals at the antenna that may cause fading of the channel
which effect the bit error rate or packet error rate of the system. Multi-path effects
serve to enhance or destroy the signal link between the programmer and the hearing
instrument. A diversity antenna system employing both polarization and spatial diversity
can help to enhance the link. Even body shadows that may affect the main line of sight
path may be mitigated by a random multi-path reflection from the ceiling or nearby
wall. By employing a diversity antenna, the system improves the chances of intercepting
a signal from the ceiling, floor, or nearby wall that is not impaired by body shadowing
effects or even other interference.
[0055] Some embodiments choose on a per packet basis the best antenna to employ based on
the best signal level or signal to noise ratio as measured during the preamble of
the signal. Some embodiments demodulate the signal from two or more receiver/antenna
pairs and keep the packet with the least errors or no errors. Some embodiments choose
one of two or more antennas based on channel metrics such as receive signal strength,
packet checksum errors, packet forward error correction errors, packet retransmission
attempts. If at any time during the communication session, the system changes antennas
based on channel metrics used to assess link quality.
[0056] For example, various station/programmer embodiments perform a channel maintenance
algorithm. After the programmer tries to adapt the RSSI threshold, the programmer
switches, based on the assessed link quality, to the opposite polarity antenna to
determine if a null due to multi-path or undesirable antenna orientation can be mitigated
using another antenna polarization or a spatially-diverse antenna. The switch can
be based on the number of retransmissions attempts and the number of checksum errors
counted since the last channel maintenance window. Should the number of errors and
retry attempts indicate a packet error rate higher than 10%, for example, over the
channel maintenance window, the programmer switches the antenna just prior to station
maintenance. Some embodiments do not switch the antennas unless both nodes have acknowledged
recent station maintenance messages containing the same alternate channel information.
This way if the link is lost following diversity antenna switching, the nodes will
rendezvous on the alternate channel together.
Transmission Frequency (Adaptive Frequency Hopping)
[0057] Various embodiments of a wireless communication system with hearing aid nodes adjust
transmission frequencies based on channel metrics. This is referred to as adaptive
frequency hopping (AFH) or channel hopping. Some system embodiments use a secondary
"look ahead" receiver to select a desirable channel that is not corrupted by interference.
Some system embodiments select a good channel using a primary receiver that time multiplexes
its task of communication with a remote device and looking ahead for a good channel
within the bandwidth. Some system embodiments use a Fast Fourier Transform (FFT) analysis
to simultaneously evaluate all potential narrow band channels for potential use by
a primary narrow band transceiver. Some system embodiments use a FFT analysis to look
ahead at all potential channels while simultaneously communicating with a narrow band
remote transceiver.
[0058] At any time during the communication session, the system may change channels based
on channel metrics used to assess link quality for the current channel and for available
channels. Because of the low power nature of the remote transceivers and the availability
of a limited bandwidth resource, some embodiments use narrow band channels with time
division multiple access and a listen before talk algorithm that allow frequency reuse
with various other services.
[0059] A secondary receiver monitors the usage of an unlicensed band to pick a desirable
channel for communicating information to and/or from a power-limited device. A primary
transceiver communicates with a remote device using narrow band channels using a modulation
scheme sufficient to convey information to and/or from a remote device. The primary
receiver picks a desirable channel to use based on a channel metric found and stored
by the secondary receiver that is continuously scanning the entire available bandwidth
looking for adequate channels for communication to the remote devices. The secondary
receiver uses a bandwidth that is substantially the same as the primary receiver so
that a good assessment can be made of how that channel would perform when used for
communication by the primary receiver.
[0060] If the channel is corrupt then the primary receiver within the base station will
not be able to receive the remote signal and information cannot be conveyed in the
uplink. The down link transmission from the station to the hearing aid does not have
the same power restrictions since the base unit has more power available and is restricted
only by the regulations governing the output power within the unlicensed band. Armed
with this knowledge the base station unit can make certain assumptions about the downlink.
For instance based on the link quality assessment (LQA) made by the primary receiver
or the secondary receiver it may or may not assume that the remote device can hear
its signal. In most cases the downlink is robust enough to assume that a command can
be received by the remote device even if the remote device cannot acknowledge its
receipt. In this way the base station primary transmitter can command the remote device
to move or "hop" to a different channel within the unlicensed band determined by the
LQA made of all other possible channels within the unlicensed band by the secondary
receiver. Once the command is made to send the remote to another viable channel the
confirmation of the frequency change command can be made with the remote device on
the new channel.
[0061] Various embodiments use a metric that involves both a peak and average detector.
Channels that exhibit low peaks as well as low average values will show up as a high
score and are a desirable channel for wireless communication. Channels having high
peaks but low averages may work well for a listen-before-talk time division multiple
access system, and thus receive a medium score. The system prefers to use a channel
with a high score, but can use a channel with a medium score. Channels occupied by
continuous narrow band signals will have a high average receive signal strength and
would show up as a poor score. Several metrics can be formed using an assigned weight.
Examples of metrics include: M
chan = W
1*RSSI
avg + W
2(RSSI
peak); and M
chan = (RSSI
avg+ RSSI
peak) RSSI
avg. A higher weight is assigned to the average received signal strength than to the
peak since Time Division Multiplex (TDM) and Listen Before Talk (LBT) systems may
be able to be used.
[0062] For example, various station/programmer embodiments perform a channel maintenance
algorithm. After the programmer tries to adapt the RSSI threshold and switch the antenna
polarization, the programmer commands the hearing aid to channel hop to the next best
channel taken from the LQA data of available channels. This channel hop is based on
the assessed link quality (e.g., the number of retransmissions attempts and the number
of checksum errors counted since the last channel maintenance window). Should the
number of errors and retry attempts indicate a packet error rate higher than 22%,
for example, over the channel maintenance window, the programmer can either command
the hearing instrument to change channels using a channel change message or alternatively
stop sending channel maintenance messages which will force the node to change channels.
[0063] If a single node is lost (no longer responding to channel maintenance messages),
it can be assumed to have changed channels to the alternative channel that was last
acknowledged by the node during a previous channel maintenance message. Because the
nodes are vulnerable to falling out of range or being interfered with, various embodiments
maintain the same alternate channel unless the alternate channel, based on current
LQA information, is severely degraded from its initial quality assessment.
Receiver Gain In Hostile RF Environment
[0064] Some device embodiments are equipped with a secondary receiver that can be employed
to access the quality of the available channels. According to some embodiments, this
secondary receiver is also equipped to access the overall RF power in the band of
operation. If the overall power across the band is above a certain threshold then
the environment can be considered "hostile" for communications between devices. Some
embodiments reduce the front end gain of the receiver to prevent overload. The reduced
front end gain allows the communications link to be maintained at a reduced range
of operation. For example, a reduced front end gain in some embodiments still allows
communication over a distance on the order of 1.5 meters. Without this change in front
end receiver gain a hostile RF environment allows the receiver to become over-loaded
by the hostile RF environment.
[0065] Various embodiments reduce one or more of the AGC_Gain, AGC_Max Gain or the AGC_Search_Gain
parameters of the receiver. Some embodiments determine a LQA score for each available
channel that is not currently being used for communication, and then sums the LQA
scores for all of these channels that are not currently being used. The United States,
for example, in one embodiment has 28 available channels. If one of the channels is
being used for communication, the LQA score of the remaining 27 channels is summed
and compared to a threshold. In another embodiment, four channels are available in
the European Union. If one of the channels is being used in the European Union, the
LQA score of the remaining 3 channels is summed and compared to a threshold. If the
sum of the LQA scores exceeds a threshold for lowering gain, then the receiver gain
is lowered. Some embodiments lower the gain by one incremental value (e.g., on the
order of 4 dB from nominal gain). The nominal gain for a band, such as within the
United States, is determined during device calibration and is stored along with other
band information in non-volatile memory. In one embodiment the threshold score will
be given by T*(N-1) where N is the number of channels being scanned minus one (the
channel in use). Where T will be the based on a factory calibration or a general metric
of the compression point of the receiver.
[0066] FIG. 14 illustrates a state diagram of an embodiment of a process performed by a
communicator to maintain link quality according to one embodiment of the present subject
matter. The normal operation occurs at state 1465. During normal operation, the average
noise, signal-to-noise ratio (SNR), and packet error rate (PER) are computed periodically.
The period of time in which certain variables are computed is known as a "channel
maintenance interval". At the conclusion of a channel maintenance interval, some of
the parameters are evaluated against corresponding thresholds such as PER and BER.
If the PER is greater than the PER threshold, the station changes channels as illustrated
at state 1468. In some embodiments, if the PER is greater than the PER threshold,
the station adjusts a diversity antenna switch as illustrated at state 1467. In some
embodiments, the station may first adjust the diversity antenna switch, re-evaluate
the PER and then change channels if the PER is still greater than the PER threshold.
If the SNR is less than the SNR threshold, the station adjusts a diversity antenna
switch as illustrated at state 1467. In the embodiment of FIG. 14, if the average
noise is not equal to the RSSI threshold plus a margin, the control adapts the RSSI
threshold as illustrated at state 1466. IN some embodiments, if the packet retry count
exceeds a packet retry count threshold, the station changes channels as illustrated
at state 1468.
[0067] Other embodiments assess the link quality using a different order. Still other embodiments
use different techniques to assess link quality, such as based on signal strength,
environmental noise strength, signal to noise ratio, and retransmission counts. Various
combinations of the different means for assessing link quality can be used. The different
methods for assessing link quality can be performed in a number of different orders.
The state diagram illustrated in FIG. 14 is provided as an example. Additionally,
the process illustrated in the state diagram of FIG. 14 can be implemented in a variety
of devices, including communicators and hearing assistance devices.
Bluetooth Low Energy Devices
[0068] Bluetooth low energy (BLE) is a distinguishing feature of Bluetooth version 4.0 wireless
communication technology that provides low-power devices with short-range low-power
wireless connectivity. Examples of such low-power devices include hearing assistance
devices, such as hearing aids. Each device having wireless connectivity, as discussed
in this document, may be a device equipped with BLE-based communication capability
(referred to as a "BLE device" herein). In other words, BLE technology may be implemented
in each of the hearing assistance devices 101A-D and the communicators 102A-D as illustrated
in FIGS. 1A-D, the communicators 202 and 302, the programmer, the hearing assistance
device, the assisted listening device, the streaming audio device, and the wireless
audio controller (WAC) as illustrated in FIGS. 2A-E and 3A-E, the WAC 405 and the
hearing assistance devices as illustrated in FIG. 4, the hearing aid device 510, the
programmer 512, the assisted listening systems 513, the device 541 that provides encoded
and compressed audio, the remote control device 515, and the other hearing aid 516
as illustrated in FIG. 5, the hearing aids 610 and programmer 612 as illustrated in
FIG. 6, the hearing aid 710 as illustrated in FIG. 7, the communicator/programmer
as illustrated in FIG. 8, and the hearing aids 910R-L and the communicator as illustrated
in FIG. 9, among other devices discussed in this document. BLE communication may be
performed between the BLE devices. Wireless test modes (also referred to as RF test
modes) are generated for design verification and manufacturing test with such devices
when implemented as BLE devices. Various embodiments use the same wireless test modes
in the field to characterize an environment where problems occur with the BLE communication
between such devices.
[0069] The Bluetooth protocol for low energy provides a test mode that requires a wired
human-computer interface (HCI) between a Bluetooth tester and a Device Under Test
(DUT). The wired HCI may include a cable connecting the DUT to the Bluetooth tester.
The present subject matter provides wireless test to the BLE protocol.
[0070] The BLE protocol includes Direct Test Modes which are normally used for testing a
physical layer link between a BLE device and a Bluetooth tester. These commands are
normally accessed through a 2-wire UART interface, but they can also be accessed through
HCI commands. Bluetooth does not support wireless test modes as part of the BLE.
[0071] The present subject matter provides BLE hearing assistance devices such as hearing
aids with wireless test modes. Various embodiments include includes one or more wireless
test modes that do not require a wired interface such as the cable, thereby making
the testing more efficient and enabling diagnostic testing in the field. Various embodiments
include such BLE wireless test capability built into a hearing assistance device such
as hearing aid and/or a device communicating with the hearing assistance device for
the BLE protocol. In various embodiments, devices with such built-in test capability
are each capable of performing a self-test of wireless communication functionalities.
In various embodiments, the wireless (RF) test modes include the Direct Test Modes,
as referred to as Non Link test modes, which verifies functionality of the physical
layer link between a BLE DUT and a BLE tester.
[0072] FIG. 15 illustrates a block diagram of Bluetooth Low Energy (BLE) device embodiment.
A system includes two or more BLE devices configured to communicate with each other
using BLE wireless communication technology. The illustrated embodiment includes a
first BLE device 1570 and a second BLE device 1572 communicatively coupled to each
other via a wireless link 1575. The BLE device 1570 includes a BLE wireless communication
circuit 1571 configured to receive and transmit data using BLE wireless communication
technology. The BLE device 1572 includes a BLE tester 1573 configured to wirelessly
communicate with the BLE device 1570 and test the BLE wireless communication circuit
1571 according to a wireless test mode in response to a test command associated with
the wireless test mode. In various embodiments, the system can include any number
of devices each including at least one of the BLE wireless communication circuit 1571
and the BLE tester 1573. In the illustrated embodiment, the BLE device 1572 includes
an analysis initiator 1574 configured to generate the test command in response to
a signal requesting a diagnostic analysis of an environment of the wireless communication.
In various embodiments, the signal requesting the diagnostic analysis may be originated
from a user or a device. In various embodiments, at least one of the BLE device 1570
and the BLE device 1572 is a hearing aid.
[0073] In various embodiments, the link quality management device (LQM) as illustrated in
FIGS. 1B-D includes a BLE tester capable of performing tests under the wireless test
mode, such as the BLE tester 1573. Each BLE device discussed in this document, including
each hearing assistance device, hearing aid, communicator, programmer, assisted listening
device, streaming audio device, WAC, device that provides encoded and compressed audio,
remote control device, may be configured to include the built-in BLE wireless test
capability, i.e., configured to be one of the BLE devices 1570 and 1572 as discussed
in this document or similar devices. In various embodiments, each of these devices
may be configured to function as a device under test and/or a tester operating under
the BLE wireless test mode.
[0074] The BLE tester 1573 represents an embodiment of the link quality management device
(LQM) as illustrated in FIGS. 1B-D. In various embodiments, the BLE tester 1573 is
configured to assess a link quality for the wireless communication channel between
the BLE tester 1573 and the BLE wireless communication circuit 1571 and provide channel
metrics indicative of the assessed quality for the wireless communication channel.
In various embodiments, the BLE tester 1573 is further configured to adjust wireless
communication over the wireless communication channel using the channel metrics for
the wireless communication channel.
[0075] The BLE tester 1573 produces at least one metric indicative of quality of data transmission
performed via the wireless link 1575 using the BLE wireless communication circuit
1571. In various embodiments, the wireless link 1575 includes a plurality of wireless
communication channels, and the BLE tester 1573 produces at least one channel metric
indicative of quality of data transmission performed via each channel of the plurality
of wireless communication channels using the BLE wireless communication circuit 1571.
Examples of channel metric include bit error rate (BER), packet error rate (PER),
cyclic redundancy check (CRC) errors, forward error correction (FEC) errors, signal
to noise ratio (SNR), number of retransmissions, and Receive Signal Strength Indicator
(RSSI). In one embodiment, the BLE tester 1573 produces a channel map indicative of
quality of data transmission using each channel of the plurality of wireless communication
channels.
[0076] FIG. 16 illustrates a block diagram of BLE hearing aid embodiment in which the BLE
device 1570 is a hearing aid 1670 and the BLE device 1572 is a communicator/programmer
1672. The hearing aid 1670 is battery-operated and includes at least a microphone,
a receiver, and signal processing circuitry, in addition to the BLE wireless communication
circuit 1571. In various embodiments, any hearing aid devices discussed in this document,
including but not limited to the hearing aids 510, 610, 710, and 910R-L, may be implemented
as the BLE hearing aid 1670.
[0077] The communicator/programmer 1672 is configured to communicate with hearing aid 1672
via wireless link 1575. In various embodiments, the communicator/programmer 1672 may
include a communicator that is capable of testing and diagnosing performance of data
transmission over the wireless link 1575 and/or a programmer that is capable of adjusting
settings of the hearing aid 1672 including parameters controlling the operation of
the BLE wireless communication circuit 1571. In various embodiments, any communicator/programmer
devices discussed in this document, including but not limited to the communicators
102A-D, 202, and 302 and the programmer 512, may be implemented as the BLE communicator/programmer
1672.
[0078] FIG. 17 illustrates a block diagram of BLE device embodiment including a BLE device
1772 that includes the BLE tester 1573. The BLE device 1772 represents an embodiment
of the BLE device 1572 or the communicator/programmer 1672 and includes the BLE tester
1573, the analysis initiator 1574, optionally an analysis timer 1780, and a user interface
1781. The user interface 1781 may include a user input device 1782 and a presentation
device 1783.
[0079] In one embodiment, the analysis initiator 1574 is configured to generate the test
command in response to a request of a user who wants to invoke a BLE wireless test
mode as a diagnostics tool for analyzing all channels in a troubled office environment.
The user input device 1782 is configured to receive the signal requesting the diagnostic
analysis of the environment of the wireless communication from the user. In one embodiment,
the analysis initiator 1574 is configured to generate the test command in response
to a request generated by a device that automatically determines a need to invoke
the BLE wireless test mode.
[0080] In one embodiment, the analysis initiator 1574 is configured to generate the test
mode according to a specified schedule, such as on a periodic basis. The analysis
timer 1780 times the specified schedule, such as a specified period, and transmits
the signal requesting the diagnostic analysis of the environment of the wireless communication
to the analysis initiator as scheduled. This provides for active analysis of the environment.
The result of the active analysis may include a list of available channels for the
data transmission over the wireless link 1575. In one embodiment, the analysis initiator
1574 generates the test command based on the specified schedule as well as the operation
status of the wireless communication circuit 1571. For example, the analysis initiator
1574 may generate the test command only when the wireless communication circuit 1571
is not receiving or transmitting data, such as when the hearing aid 1672 is in an
idle state.
[0081] In response to the test command, the BLE tester 1573 performs an analysis including
one or more wireless test modes. The outcome of the analysis may include the channel
metrics and/or the channel map. In various embodiments, portions of the outcome of
the analysis, such as selected channel metrics and the channel map, are presented
using the presentation device 1783. In various embodiments, the outcome of the analysis
may be used to enable or disable each channel of the plurality of wireless channels
on the wireless link 1575 and/or provides clues to the user, such as a technical support
specialist, as to why the user is unable to achieve the throughput or connections
as specified by the hearing aid manufacturer.
[0082] Examples of the test command include a Transmitter Test command and a Receiver Test
commands. These commands enable the device to transmit or receive test packets of
a specified length with a specified modulation on a specified channel. The Receiver
Test command returns the number of packets received during the burst of packets transmitted
in response to the Transmitter Test command. An estimation of the number of packets
transmitted can be done by using timers to control the length of time the base unit
sends packets. The transmitter test commands results in one packet being sent every
625 µs. The BLE tester can calculate an approximate packet error rate (PER) from these
values.
[0083] Examples of the test command also include a Get RSSI command associated with a Get
RSSI mode. A Get Channel Map command associated with a Get Channel Map mode, and a
Set Channel Map command associated with a Set Channel Map mode. The Get RSSI mode
functions (in obtaining the channel metrics) when a valid packet is received. If interference
exists in the wireless communication environment causing packets to be missed on a
given channel, the Get RSSI command will return a value of "0" for that channel.
[0084] The Get Channel map mode is responded with a current channel map for the wireless
communication environment. If adaptive frequency hopping (AFH) is employed, channels
that are interfered with are removed from the channel map by the AFH algorithm. The
Set Channel Map mode allows the user to enable, or disable channels independent of
AFH.
[0085] Various wireless test modes for testing a BLE based hearing aid have been tested
using a personal computer and/or another device configured to wirelessly communicate
with the hearing aid and function as the BLE tester. In various embodiments, the test
command may be associated with one or more of these wireless test modes. In the following
examples (1-6) of the wireless test modes, "the PC" refers to the personal computer
and/or the other device, and "the HA" refers to the hearing aid under test. The Examples
include:
- 1) Continuous packet transmit mode. The HA transmits packets with psuedo random data
over the BLE channels, to be used by the PC for RF characterization.
- 2) Downlink PER test mode. The PC transmits bursts of data. The HA receives the bursts
of data and calculates PER.
- 3) Uplink PER test mode. The HA transmits bursts of data. The PC receives the bursts
of data and calculates PER.
- 4) Echo packet mode. The PC transmits a packet. The HA echoes the packet. The HA retransmits
the packet. The PC receives the echoed packet and calculates PER.
- 5) Antenna test profile model. The HA transmits an unmodulated carrier signal. The
PC detects the transmitted signal.
- 6) RSSI test mode. The HA has ability to report RSSI. The PC sets up connection with
the HA and transmits "send RSSI packet". The HA receives "send RSSI packet" and calculates
RSSI for received packet. The HA then sends packet with received RSSI value and channel
number. The PC iterates on next channel in sequence. This process repeats for user
a specified number of channels.
[0086] These example wireless test modes may be used for the BLE wireless communication
as well as wireless communication in general, including communications over the wireless
links discussed in this document. In various embodiments, the wireless test modes
can also aid manufacturing test, especially when wireless testing is not supported
in a conventional communication protocol, such as with the BLE protocol.
[0087] FIG. 18 illustrates an embodiment of a method for managing a BLE wireless communication
link. In one embodiment, the method is performed using the BLE tester 1573, with a
device including the wireless communication circuit 1571 as the DUT. In various embodiments,
the device includes a hearing aid.
[0088] At 1885, wireless communication is performed with the hearing aid using BLE wireless
communication technology. At 1886, a diagnostic analysis of an environment of the
wireless communication is performed. Various embodiments of the diagnostic analysis
use one or more of the wireless test modes discussed in this document, including the
wireless test modes according to which the BLE tester 1573 performs a test in response
to the test command. In one embodiment, the diagnostic analysis is performed in response
to a request from a user, such as when the user encounters difficulty in communicating
with the hearing aid. In another embodiment, the diagnostic analysis is performed
according to a specified schedule, such as on a periodic basis to actively assess
the environment of the wireless communication.
[0089] FIG. 19 illustrates an embodiment of a method for performing the diagnostic analysis.
At 1990, a wireless link is established between the hearing aid and the BLE tester
for the diagnostic analysis. At 1991, the hearing aid is tested for quality of data
transmission associated with the wireless link according to a specified wireless test
mode. At 1992, information indicative of one or more characteristics of the environment
of the wireless communication is produced. In various embodiments, the information
includes at least one channel metric for each channel of a plurality of wireless communication
channels. The channel metric is indicative of quality of data transmission performed
using each channel. Examples of the channel metric include BER, PER, CRC errors, FEC
errors, SNR, number of retransmissions, and RSSI. In various embodiments, the information
may also include a channel map indicative of quality of data transmission using each
channel of the plurality of wireless communication channels. In various further embodiments,
the hearing aid is reprogrammed for adjusting the settings related to the wireless
communication using the channel metrics and/or the channel map.
[0090] In various embodiments, the circuit of each device discussed in this document, including
each circuit of various elements of the BLE devices 1570 and 1572 as discussed in
this document, is implemented using hardware, software, firmware or a combination
of hardware, software and/or firmware. In various embodiments, the BLE tester 1571
may be implemented using one or more circuits specifically constructed to perform
one or more functions discussed in this document or one or more general-purpose circuits
programmed to perform such one or more functions. Examples of such general-purpose
circuit can include a microprocessor or a portion thereof, a microcontroller or portions
thereof, and a programmable logic circuit or a portion thereof.
[0091] The present subject matter is demonstrated for hearing assistance devices, including
hearing aids, including but not limited to, behind-the-ear (BTE), in-the-ear (ITE),
in-the-canal (ITC), receiver-in-canal (RIC), or completely-in-the-canal (CIC) type
hearing aids. It is understood that behind-the-ear type hearing aids may include devices
that reside substantially behind the ear or over the ear. Such devices may include
hearing aids with receivers associated with the electronics portion of the behind-the-ear
device, or hearing aids of the type having receivers in the ear canal of the user,
including but not limited to receiver-in-canal (RIC) or receiver-in-the-ear (RITE)
designs. The present subject matter can also be used in hearing assistance devices
generally, such as cochlear implant type hearing devices. It is understood that other
hearing assistance devices not expressly stated herein may be used in conjunction
with the present subject matter.
[0092] One of ordinary skill in the art will understand that, the modules and other circuitry
shown and described herein can be implemented using software, hardware, and combinations
of software and hardware. As such, the terms module and circuitry, for example, are
intended to encompass software implementations, hardware implementations, and software
and hardware implementations.
[0093] Further, the following constitute embodiments of the invention:
Embodiment 1: A system for managing wireless communication for a hearing aid, comprising:
a first device including a Bluetooth Low Energy (BLE) wireless communication circuit
configured to receive and transmit data using BLE wireless communication technology;
and a second device including a BLE tester configured to wirelessly communicate with
the first device and test the BLE wireless communication circuit according to a wireless
test mode in response to a test command associated with the wireless test mode, the
second device including an analysis initiator coupled to the BLE tester and configured
to generate the test command in response to a signal requesting a diagnostic analysis
of an environment of the wireless communication, wherein at least one of the first
device and the second device includes the hearing aid.
Embodiment 2: The system of embodiment 1, wherein the first device comprises the hearing
aid, and the second device comprises a communicator configured to wirelessly communicate
with the hearing aid.
Embodiment 3: The system of embodiment 2, wherein the communicator comprises a user
input device configured to receive the signal requesting the diagnostic analysis of
the environment of the wireless communication from a user.
Embodiment 4: The system of any of embodiments 1 to 3, wherein the second device comprises
a timer configured to generate the signal requesting the diagnostic analysis of the
environment of the wireless communication according to a specified schedule.
Embodiment 5: The system of any of embodiments 1 to 4, wherein the BLE tester is configured
to produce at least one metric indicative of quality of data transmission performed
using the BLE wireless communication circuit and adjust the BLE wireless communication
circuit using the at least one metric produced in response to the test command.
Embodiment 6: The system of any of embodiments 1 to 5, wherein the BLE wireless communication
circuit is configured to receive and transmit the data using a channel of a plurality
of wireless communication channels, and the BLE tester is configured to produce a
channel map indicative of quality of data transmission using each channel of the plurality
of wireless communication channels in response to the test command.
Embodiment 7: The system of embodiment 6, wherein the BLE tester is configured to
enable or disable each channel of the plurality of wireless communication channels
for use by the BLE wireless communication circuit to receive and transmit the data
using the channel map produced in response to the test command.
Embodiment 8: The system of any of embodiments 1 to 5, wherein the BLE wireless communication
circuit is configured to receive and transmit the data using a channel of a plurality
of wireless communication channels, and BLE tester is configured to produce at least
one channel metric for each channel of the plurality of wireless communication channels,
the channel metric indicative of quality of data transmission performed using the
each channel.
Embodiment 9: The system of embodiment 8, wherein the BLE tester is configured to
test the BLE wireless communication circuit according to a wireless test mode for
evaluating a packet error rate for each channel of the plurality of wireless communication
channels.
Embodiment 10: The system of embodiment 8, wherein the BLE tester is configured to
test the BLE wireless communication circuit according to a wireless test mode for
evaluating a received signal strength indicator for each channel of the plurality
of wireless communication channels.
Embodiment 11: A method for wirelessly communicating with a hearing aid, comprising:
performing wireless communication with the hearing aid using Bluetooth Low Energy
(BLE) wireless communication technology; performing a diagnostic analysis of an environment
of the wireless communication, including: establishing a wireless link between the
hearing aid and a BLE tester for the diagnostic analysis; testing the hearing aid
for quality of data transmission associated with the wireless link according to a
specified wireless test mode; and producing information indicative of one or more
characteristics of the environment of the wireless communication.
Embodiment 12: The method of embodiment 11, wherein testing the hearing aid comprises
producing at least one channel metric for each channel of a plurality of wireless
communication channels, the channel metric indicative of quality of data transmission
performed using the each channel.
Embodiment 13: The method of embodiment 12, wherein producing the at least one channel
metric comprises producing one or more of a packet error rate and a received signal
strength indicator for each channel of the plurality of wireless communication channels.
Embodiment 14: The method of any of embodiments 11 to 13, wherein testing the hearing
aid comprises producing a channel map indicative of quality of data transmission using
each channel of a plurality of wireless communication channels.
Embodiment 15: The method of embodiment 14, further comprising enabling or disabling
each channel of the plurality of wireless communication channels for performing the
wireless communication using the channel map.
[0094] The methods illustrated in this disclosure are not intended to be exclusive of other
methods within the scope of the present subject matter. Those of ordinary skill in
the art will understand, upon reading and comprehending this disclosure, other methods
within the scope of the present subject matter. The above-identified embodiments,
and portions of the illustrated embodiments, are not necessarily mutually exclusive.
These embodiments, or portions thereof, can be combined. In various embodiments, the
methods are implemented using a data signal embodied in a carrier wave or propagated
signal, that represents a sequence of instructions which, when executed by one or
more processors cause the processor(s) to perform the respective method. In various
embodiments, the methods are implemented as a set of instructions contained on a computer-accessible
medium capable of directing a processor to perform the respective method. In various
embodiments, the medium is a magnetic medium, an electronic medium, or an optical
medium.
[0095] The above detailed description is intended to be illustrative, and not restrictive.
Other embodiments will be apparent to those of skill in the art upon reading and understanding
the above description. The scope of the invention should, therefore, be determined
with reference to the appended claims, along with the full scope of equivalents to
which such claims are entitled.