JP2020031429A - New method of wireless transmission of digital audio - Google Patents

Abstract

To provide a hearing device and a method of wireless communication of data with different priorities in compliance with a Bluetooth Low Energy (LE) standard.SOLUTION: A method of wireless transmission of data sets by a hearing aid (a left ear hearing aid 10L and a right ear hearing aid 10R) provided with a transmitter (smartphone 50) includes: transmitting a first data set of a first data category from the transmitter for reception by a receiver in a first connection event; and re-transmitting the first data set in the first connection event if an acknowledgement of receipt from the receiver is absent, or transmitting a second data set of a second data category that is different from the first data category from the transmitter to the receiver in the first connection event if the acknowledgement of receipt from the receiver is present.SELECTED DRAWING: Figure 1

Description

  A new method of wirelessly communicating data having different priorities is provided, for example, in accordance with the Bluetooth Low Energy (LE) standard. A novel hearing device configured to be suitable for wireless communication in a novel way is also provided.

Bluetooth LE, defined in the Bluetooth Core Specification 4.1 or earlier, does not allow audio transmission. There are some limitations to the protocol as defined, which means that audio transmission is not feasible without changing some protocol layers.
The nature of the L2CAP channel defined for the LE, which defines a best-effort data transmission scheme that does not use timeouts or flushes when transmitting, the real-time audio transmission via the LE as defined; It means that it is almost impossible to perform the service.
The absence of real time transmission means also means that stereo synchronization between two paired audio sinks (such as hearing aids) is almost impossible.
The packet size means that the overhead for transmitting the data rates required for audio (typically 32-48 kbit / s) is very high;

  It is an object of the new method and hearing device to overcome the above mentioned disadvantages.

A novel method for wirelessly communicating a data set is provided, comprising:
a) transmitting a first data set of a first data category from a transmitting device to a receiving device.
b) retransmitting the first data set if there is no acknowledgment of reception from the receiving device.
c) If there is an acknowledgment of the reception from the receiving device, if there is no acknowledgment, when the transmitting device and the receiving device are connected for retransmission, for example, a first data set of a first data category Transmitting, from the transmitting device to the receiving device, a second data set of a second data category different from the first data category in the same connection event in which was transmitted.

Further, a novel method for wirelessly communicating data having different priorities is provided, comprising:
a) transmitting a first data set of a first priority from a transmitting device to a receiving device.
b) retransmitting the first data set of the first priority if there is no acknowledgment of reception from the receiving device.
c) If there is an acknowledgment of reception from the receiving device, otherwise the transmitting device and the receiving device have a second priority lower than the first priority when the receiving device is connected for retransmission. Transmitting the second data set from the transmitting device to the receiving device.

  The first data category may include an audio data set.

  The second data category includes various control data such as start, stop, codec negotiation, and / or the like, according to the Bluetooth LE standard protocol as defined in the Bluetooth Core Specification 4.1 or earlier. Or it may include data from other devices, for example, devices with sensors such as environmental sensors such as temperature sensors.

  The first data set may be an audio data set. The audio data set includes digital audio signal values, such as a sequence of discrete time and discrete amplitude digital audio signal values, wherein the sequence of discrete time and discrete amplitude digital audio signal values is an analog audio signal. It represents continuous time and continuous amplitude values, and the analog audio signal can be converted to sound. In other words, as is well known in the streaming audio art, an audio data set contains digital data that is intended to be converted to sound at some point.

  Preferably, the audio data set has a high priority and a lower priority to ensure high fidelity or at least acceptable quality of the sound generated based on the transmitted audio data set Ensure that the audio data set is transmitted before transmitting other types of data sets with a degree.

  A data set, including an audio data set, can be a data packet having two types of data: control information and data. Data is also known as payload or payload data. The control information provides information data needed by the network to deliver the data, ie, the payload, to the intended receiving device, such as source and destination device addresses, error detection codes, and order control information. Typically, control information is found in the header and trailer of the packet, with the payload data in between.

The method may further include:
d) signaling from the transmitting device to the receiving device whether the data set having the second priority is waiting to be transmitted to the receiving device.
e) between the transmitting device and the receiving device for transmission of the second data set having the second priority, if there is no data set having the second priority waiting for transmission to the receiving device; Stopping establishing a connection for the server.

  The information as to whether the data set having the second priority is waiting for transmission to the receiving device may be encoded in a single data byte, such as a single data bit.

  The method may be compliant with the Bluetooth Low Energy standard, such as the Bluetooth Core Specification 4.1 or earlier, and preferably, the transmission of the audio data set is performed within successive connection events. Will be implemented.

  The method may be used in accordance with the Bluetooth Low Energy standard, such as the Bluetooth Core Specification 4.1 or earlier, for example for audio streaming of audio and music.

  The method may further include allocating an L2CAP channel for transmission of the audio data set, eg, allocating one L2CAP channel to control data associated with the audio data set and / or One L2CAP channel may be assigned to the first audio data set and another L2CAP channel may be assigned to the second audio data set if possible.

The following three fixed L2CAP channels may be allocated for audio transmission.
1) Control data (start, stop, codec negotiation, etc.)
2) Left audio data 3) Right audio data

  Only a device capable of receiving one audio stream (left or right), for example in a hearing aid, channels 1) and 2) or channels 1) and 3) will be used for that device. Devices with integrated stereo functionality, such as stereo headsets, use all three channels. The audio data set may be unidirectional or bidirectional depending on the application, and the control data channel should allow negotiation on that point.

The connection configuration may be performed, for example, by the following procedure.
1. The unique UUID informs the receiving device that it can receive prioritized and flushable L2CAP (PFL2CAP) data with priority.
2. The transmitting device discovers the receiving device, connects to the receiving device, and queries the PFL2CAP service about its function.
3. The receiving device responds with a PFL2CAP configuration. For example, for audio, this includes which codec the receiving device provides, and what content the receiving device is to receive on which L2CAP channel and in what priority, eg (channel 127, high priority, left Audio), (channel 128, high priority, right audio), and (channel 129, low priority, audio control information).
4. The transmitting device acknowledges the reception by transmitting additional information about the data, eg, information regarding content, codec and frame size, flash timeout, and the like.
5. Both the transmitter and the receiver set up a new L2CAP channel, prepare the audio stream, and adjust the connection rate to match the product of the specified frame rate times the number of retransmissions.

For example, the operation of the transmitting device while streaming audio may include the following.
1. The host of the transmitter controller initiates processing of the audio stream and processes the first audio frame to be encoded and queued for immediate transmission on the designated L2CAP channel (s). . The host then proceeds to process the next audio frame.
2. At the same time, the control layer attempts to send the packets in priority order. As soon as the transmission is successful, the control layer signals success and requests the next packet from the host. If a packet is flushed due to a timeout, the control layer signals the failure and also requests the next packet.
3. Audio control information from the host, eg, volume changes, is queued in the designated L2CAP channel. The controller transmits the packet when there is no pending transmission packet with a higher priority.

  The method further includes determining that, in the absence of an acknowledgment of receipt from the audio data set receiving device, the number of retransmission attempts of the same audio data set is less than a predetermined maximum value, e.g., equal to two. The condition may include retransmission of the audio data set.

  The number of attempts to retransmit one or more types of data may not be limited, i.e., no maximum value is assigned to one or more types of data, or in other words, one Alternatively, the maximum value assigned to a plurality of types of data is infinite, for example, 0xFFFF.

  Different types of data may have different maximum values for retransmission attempts, for example, an audio data set may have a maximum value of 2, while having a lower priority than the audio data set priority. Maximum value of the data set with priority.

  For example, the new method may implement an L2CAP flush timeout, which is also defined for the Bluetooth Basic Rate (BR) L2CAP channel. Preferably, this timeout corresponds to two connection events for the channel carrying the audio data after the data has been posted via HCI (ie, a first retry event for L2CAP audio is enabled). No.) On the other hand, the remaining channels remain at 0xFFFF.

  On a typical link, packets may be lost at a rate that is not suitable for audio. Thus, retransmission is preferably possible and preferably takes place on a different channel. Therefore, the MD function of Bluetooth LE cannot be used for retransmission. Therefore, an audio data set with a flash timeout should simply be tried once within the connection interval. To allow retransmission, the connection interval must be half of the audio frame size, so if the audio frame is 10 ms, the connection interval should be 5 ms. This is facilitated by using existing link layer control packets.

  The MD function may be used to transmit low priority data within the same connection event, but the receiving device may not accept the MD bit, for example, a hearing aid will not accept the MD bit.

  To reduce the power consumption of the receiving device, the transmitting device indicates that there is low-priority data in a waiting state, whether or not to transmit data in the same connection event after high-priority data For this purpose, the MD bit may be set in the high priority packet. If no low priority data is waiting, the MD bit is reset. This allows the receiving device to skip dataless connection events between successful transmissions of the high priority audio data set in response to the value of the received MD bit. Similarly, the transmitting device may skip waiting data-less connection events during audio streaming to save power and / or increase interoperability with other wireless services. It is possible.

  Note that when transmitting a non-audio data set, without the L2CAP flush timeout, the link will be occupied until the data is acknowledged. This rarely results in audio dropouts, which have to be dealt with by packet loss concealment at the receiving end, as disclosed, for example, in EP2605547A1.

  The method further includes transmitting, from the transmitting device, at least one receiving device configured to receive the audio data set to at least two different receiving devices connected to receive the different audio data sets. And transmitting synchronous data including timing information related to the transmission delay difference.

  The determination of the synchronization data may be based on a ping transmission from the transmitting device to at least two different receiving devices, for example, a ping transmission using an L2CAP control channel.

  Preferably, during stereo audio streaming, the transmitting device communicates the time offset between the links to a preceding receiving device in the link, thereby delaying the received audio accordingly, thus providing two stereo audio streams. Channels can be properly synchronized. The time offset can be determined using a network latency measurement that implements a ping via the control channel. This ping allows the sending host to calculate the time offset.

  Stereo audio streaming can also be implemented using a single link. For example, during stereo audio streaming to headphones, both the left L2CAP channel and the right L2CAP channel may be transmitted using the same link, thereby keeping both the receiving device and the transmitting device simple. Is done. Since headphones can withstand higher wireless duty cycles, the MD functionality of Bluetooth LE may be used for this purpose. In this way, the same connection event can carry information about both the left and right channels, and the packet structure can remain the same as in mono or dual sync. This simplifies implementation on both sides. This is because the transmission host needs to change only the connection handle for audio as compared with the dual sync case.

  The following table outlines the number of bytes required to hold an audio data set given a particular audio frame size in ms. These values are for an audio stream flowing at 48 kbit / s. In the case of an audio stream of 32 kbit / s, it becomes 2/3 of this request.

  To minimize overhead, match the LL MTU size to the L2CAP MTU plus header and MIC so that the method or controller that implements L2CAP audio preferably supports long packets, And preferably equal to the required payload size.

  Advantageously, the new method facilitates the transmission of audio data sets using Bluetooth LE by utilizing the control and link layer extensions of Bluetooth LE in a limited way, for example: Operations related to security and link setup are performed as specified in the Bluetooth Core Specification.

  There is also provided a hearing device having a communication controller adapted to operate according to the novel method according to any of the appended claims.

  Hearing devices include BTE, RIE, ITE, ITC, CIC and other hearing aids, binaural hearing aids, ear-hook, in-ear, on-ear, over-ear, behind-neck, helmet, headguard A headset such as a type, a headphone, an earphone, an ear defender, an earmuff, or the like may be used.

Preferably, the communication controller is adapted for audio transmission and / or reception of audio using the Bluetooth LE L2CAP, preferably the communication controller comprises:
-Corresponds to L2CAP flush timeout = 2-Corresponds to prioritized L2CAP traffic-Configures to accommodate LL packet sizes up to 120 bytes, depending on bit rate and audio frame size selection Is done.

  Accordingly, there is provided a novel hearing aid capable of performing wireless communication in accordance with the Bluetooth LE standard protocol.

A new hearing aid
An input transducer configured to output an audio signal based on a signal representing the sound provided thereto, and a hearing loss compensation unit that compensates for hearing loss of a user of the hearing aid and outputs an audio signal compensated for hearing loss. For example, the hearing aid may be configured to reduce the loudness of a given signal as perceived by a hearing-impaired person to the sound of a hearing-loss-compensated signal perceived by a user. A handset, embedded type, which can be aimed at regaining the loudness to approximately match the loudness and further configured to output an auditory output signal based on the audio signal compensated for hearing loss An output transducer, such as a transducer, wherein the human auditory system can receive the auditory output signal, thereby allowing the user to hear sound An output transducer, and it may include a communication controller.

  A transducer is a device that converts a signal provided to the transducer in one form of energy to a corresponding output signal in another form of energy.

  The input transducer may comprise a microphone, which converts the acoustic signal applied to the microphone into a corresponding analog audio signal whose instantaneous voltage varies continuously with the sound pressure of the acoustic signal. I do.

  The input transducer may include a telecoil. The telecoil converts a fluctuating magnetic field in the telecoil into a corresponding analog audio signal, a fluctuating analog audio signal in which the instantaneous voltage varies continuously with the fluctuating magnetic field strength in the telecoil. Telecoils can be used to generate audio from speakers speaking to multiple people, for example, in public places such as churches, auditoriums, theaters, movie theaters, or through loudspeakers in train stations, airports, shopping malls, etc. Can be used to increase the signal to noise ratio. Voice from the speaker is converted to a magnetic field using an inductive loop system (also called a "hearing loop"), and a telecoil is used to magnetically pick up the magnetically transmitted voice signal.

  The input transducer may further comprise at least two spaced microphones and a beamformer configured to combine the microphone output signals of the at least two spaced microphones into a directional microphone signal.

  The input transducer includes one or more microphones, a telecoil, and a switch for selecting, for example, an omnidirectional microphone signal, or a directional microphone signal, or a telecoil signal, alone or in any combination, as an audio signal. May be provided.

  Typically, an analog audio signal is converted to a corresponding digital audio signal in an analog-to-digital converter, whereby the amplitude of the analog audio signal is represented in a binary number, thereby enabling digital signal processing. It will be suitable. Thus, a discrete-time and discrete-amplitude digital audio signal in the form of a series of digital values represents a continuous-time and continuous-amplitude analog audio signal.

  Throughout this disclosure, "audio signal" may be used to identify any analog or digital signal that is part of a signal path from the output of an input transducer to the input of a hearing loss processor.

  Throughout this disclosure, a "hearing loss compensated audio signal" is any part of the signal path from the output of the hearing loss processor, possibly through a digital-to-analog converter, to the input of the output transducer. Can be used to identify the analog or digital signal of the

  Hearing aids can include a transceiver with both a wireless transmitter and a wireless receiver. The transmitter and the receiver may share a common circuit and / or a single housing. Alternatively, the transmitter and the receiver may not share a circuit, and the wireless communication unit may comprise a separate device with a transmitter and a receiver, respectively.

  The hearing aids advantageously use the Bluetooth LE standard protocol, for example, for two hearing aids to digitally exchange data such as audio signals, control data such as signal processing parameters, signal processing program identifiers, and the like. It may be incorporated into a binaural hearing aid system that is interconnected and optionally interconnected with other devices, such as a tablet computer, a smartphone (eg, IPphone, Android phone, Windows phone, etc.), a handheld device such as a remote control, etc. .

Typically, only a limited amount of power is available from the hearing aid power supply. For example, power is typically supplied from a conventional ZnO ₂ battery in the hearing aid.

  In designing hearing aids, size and power consumption are important considerations.

  The signal processing in the new hearing aid may be performed by dedicated hardware, or in one or more signal processors, or by dedicated hardware and one or more signal processors. May be implemented in combination.

  Similarly, the operations of the communication controller may be performed by dedicated hardware, or may be performed on one or more processors, or on a combination of dedicated hardware and one or more processors. May be implemented.

  As used herein, the terms "processor," "signal processor," "controller," "system," and the like, refer to CPU-related, either hardware, a combination of hardware and software, software, or running software. Shall be referred to.

  For example, "processor", "signal processor", "controller", "system", and the like include, but are not limited to, a process executed on a processor, a processor, an object, an executable, a thread of execution, And / or programs.

  By way of example, the terms "processor," "signal processor," "controller," "system," and the like, refer to both an application running on a processor and a hardware processor. One or more "processors," "signal processors," "controllers," "systems," etc., or any combination thereof, may reside within a process and / or thread of execution, one or more. Multiple "processors", "signal processors", "controllers", "systems", etc., or any combination thereof, centralized on one hardware processor, possibly in combination with other hardware circuits And / or may be distributed between two or more hardware processors, possibly in combination with other hardware circuits.

  Also, a processor (or similar term) may be any component that can perform signal processing, or any combination of such components. For example, the signal processor may be an ASIC processor, an FPGA processor, a general-purpose processor, a microprocessor, a circuit component, or an integrated circuit.

  In the following, the novel method and the hearing aid will be described in more detail with reference to the drawings.

FIG. 3 schematically illustrates a binaural hearing aid system receiving audio streaming from a smartphone according to a novel method. FIG. 4 schematically illustrates an example of transmitting an audio data set according to a novel method. FIG. 4 schematically illustrates another example of transmitting an audio data set according to a novel method. FIG. 4 schematically illustrates another example of transmitting an audio data set according to a novel method. FIG. 4 schematically illustrates another example of transmitting an audio data set according to a novel method. FIG. 4 schematically illustrates another example of transmitting an audio data set according to a novel method. FIG. 4 schematically illustrates another example of transmitting an audio data set according to a novel method. 5 is a flowchart of an example of a new method. 5 is a flowchart of another example of the novel method. 5 is a flowchart of another example of the novel method. 5 is a flowchart of another example of the novel method.

  In the following, various examples of the novel method and the hearing device are shown. However, the novel methods and hearing devices described in the appended claims may be embodied in various forms and should not be construed as limited to the examples set forth herein.

  Note that the accompanying drawings are schematic, simplified for clarity, and show only the details essential for understanding the novel method and hearing aid; other details have been excluded.

  Like reference numbers refer to like elements throughout. Therefore, similar elements will not be described in detail in the description of each drawing.

  FIG. 1 schematically shows a binaural hearing aid system comprising a left ear hearing aid 10L and a right ear hearing aid 10R, wherein the left ear hearing aid 10L and the right ear hearing aid 10R are respectively a smartphone or a mobile phone, an audio-enabled tablet, a cordless phone, a television receiver. A wireless communication unit for connection to another audio-capable communication device, such as a device. In the present embodiment, the left ear hearing aid 10L and the right ear hearing aid 10R are connected to the smartphone 50 via the corresponding wireless communication links 12L and 12R, respectively. One skilled in the art will appreciate that in other embodiments of the system where the right hearing aid 10R is optional, the binaural hearing aid system may include only a single hearing aid, such as 10L.

  The unique ID identifies every device in the binaural hearing aid system. The illustrated binaural hearing aid system is generally configured to operate in accordance with Bluetooth Low Energy (Bluetooth LE), for example, corresponding to Bluetooth Core Specification version 4.1. Thus, the illustrated binaural hearing aid system is configured to operate in the 2.4 GHz industrial, scientific and medical (ISM) band according to Bluetooth LE and includes 80 frequency channels with a 1 MHz bandwidth. However, as described in more detail below, the Bluetooth LE controller of each of the left ear hearing aid 10L and the right ear hearing aid 10R and the wireless communication unit of the smartphone 50 provides real-time audio audio through each wireless communication link 12L, 12R. It has been modified to allow transmission of the data set.

The left hearing aid 10L and the optional right hearing aid 10R may be substantially the same and one can expect for the unique ID described above, so the following description of the features of the left hearing aid 10L will be given to the right hearing aid 10R. The same is true. Left hearing aid 10L may include a ZnO ₂ battery (not shown) that is connected to supply power to hearing aid circuit 14. The left hearing aid 10L includes an input transducer in the form of a microphone 16. When the left hearing aid 10L is operating, the microphone 16 outputs an analog or digital audio signal based on the acoustic signal reaching the microphone 16. When the microphone 16 outputs an analog audio signal, the hearing aid circuit 14 converts the analog audio signal to a corresponding digital audio signal so that the digital audio signal can be processed in the hearing aid circuit 14. A converter (not shown) may be provided. Specifically, it may be provided in a hearing loss processor 24L configured to compensate for hearing loss of a user of the left hearing aid 10L. Preferably, the hearing loss processor 24L comprises a dynamic range compressor known in the art by compensating for the frequency dependent loss of the user's dynamic range, often referred to in the art as a replenishment phenomenon. Accordingly, the hearing loss processor 24L outputs the audio signal compensated for the hearing loss to the loudspeaker or the receiver 32. The loudspeaker or receiver 32 converts the audio signal compensated for hearing loss into a corresponding acoustic signal, and sends the signal to the user's eardrum. Thus, the user hears the sound reaching the microphone, but compensated for the individual hearing loss of the user. The hearing aid has a sound volume of an acoustic signal that reaches the microphone 16 such that a sound loss-compensated signal perceived by a user wearing the hearing aid 10 perceives by a listener having normal hearing. It may be configured to recover the loudness of the sound so as to substantially match the sound.

  Hearing aid circuit 14 also includes a wireless communication unit comprising a radio section or radio circuit 34L configured to communicate wirelessly with smartphone 50. The wireless communication unit includes a Bluetooth LE controller 26L that performs various communication protocol related tasks and possibly other tasks. The operation of the left hearing aid 10L can be controlled by a suitable operating system. The operating system manages the hardware and software resources of the hearing aid, including, for example, the hearing loss processor 24L and possible other processors and associated signal processing algorithms, wireless communication units, some memory resources, and the like. May be configured. The operating system may schedule tasks so that the resources of the hearing aid can be used efficiently and reduce costs, including power consumption, processor time, storage locations, wireless transmission, and other resources. May include accounting software for assigning

  The operating system controls the wireless circuit 34L to perform wireless communication with the smartphone 50 according to the Bluetooth LE protocol that has been modified to be audio-compatible. In connection with the two-way data communication between devices based on the modified Bluetooth LE protocol, the smartphone 50 can operate as a master device and the left hearing aid 10L may operate as a slave.

  The smartphone 50 includes a wireless unit or wireless circuit 54 configured to wirelessly communicate with a corresponding wireless unit or wireless circuit 34L of the left hearing aid 10L. The smart phone 50 also includes a wireless communication unit, which includes a Bluetooth LE controller 56 that performs various communication protocol related tasks and possibly other tasks according to the modified Bluetooth LE protocol. Data packets or data sets to be transmitted via the wireless communication link 12L are provided to the wireless circuit 54 by the Bluetooth LE controller 56. The data packet received by the radio or radio circuit 54 via the RF antenna 53 is sent to a Bluetooth LE controller 56 for further data processing. Those skilled in the art will appreciate that smartphone 50 typically includes a number of additional hardware and software resources in addition to those shown schematically, as is well known in the mobile phone art. .

  FIG. 2 illustrates a data set having different priorities, for example, between the left ear hearing aid 10L and the smartphone 50 described above, for example, with the smartphone 50 configured as a master and the hearing aid 10L configured as a slave. 1 is a first timing diagram 200 illustrating a novel method of wirelessly communicating with.

  FIG. 2 shows that the transmission of each data packet or data set from the transmitting device is successful in the first transmission attempt and therefore requires retransmission, in which the coherent electromagnetic noise in the associated data channel is low. 1 shows the operating state of a wireless communication link (12L in FIG. 1) without a link.

  Successive connection events on the wireless communication link are indicated by Ci1, Ci2, Ci3, etc. along the time axis t. Those skilled in the art will appreciate that the illustrated adjacent connection events, such as Ci1 and Ci2, can be separated by a fairly long sleep period, eg, up to 4 seconds, according to the Bluetooth LE protocol. During such a sleep period, both the wireless circuit 34L of the left hearing aid 10L and the wireless circuit 54 of the smartphone 50 can be powered down to reduce power consumption. A connection event may have a duration or connection interval between 5 ms and 10 ms. The connection interval between each connection event is preferably selected to be one half of the selected audio frame size of the audio data set transmitted over the wireless communication link.

  Table 2 below schematically illustrates the number of bytes required to hold audio data given a particular audio frame size in milliseconds. The listed values are for audio streams flowing at 48 kbit / s. In the case of an audio stream of 32 kbit / s, it becomes 2/3 of this request.

  Two types of data having different priorities are transmitted over the wireless communication link, as shown in FIG. 2 by the data packets 205, 210, 215 or data set symbols "A" and "D". The data packets denoted by A1 and A2 have data of a first priority, and data packet D has a second priority lower than the first priority. In the illustrated example, the first or high priority data packets 205, 215 include an audio data set, and the lower priority data packet 210 has a Bluetooth core specification 4.1 or It includes various control data such as start, stop, codec negotiation, etc. according to the Bluetooth LE protocol according to the earlier version. The data structure of each of the high priority data packets A1, A2 is indicated by data packet 230. High priority data packet 230 includes a header section 235 that may have two bytes. The high priority data packet 230 further includes the payload data 240 described above, which may include between 60 and 120 bytes of audio data depending on the audio frame size. A 60 byte payload data size would be approximately 1.5 ms long in each high priority data packet, which would fit in the time window of each corresponding connection event. The header section 235 preferably includes a so-called more data (MD) field or bit, indicated by the symbol “1”. This MD field indicates whether there is a low priority data packet D waiting. The Bluetooth LE controller 56 of the transmitting device sets the MD bit if there is a low-priority data packet D in a waiting state, and sets the MD bit to “if there is no low-priority data D in a waiting state. Reset to "0". The Bluetooth LE controller 56 preferably sets the MD bit regardless of whether the transmitting device actually transmits the low priority data packet D in the same connection event Ci1 after the high priority data packet A1. It is configured to set or reset. This feature allows the receiving device to skip connection events where there is no pending low priority data packet D between successful high priority data packet connection events by examining the MD bit, or It can be eliminated.

  The low priority data packet D may have a length of 37 bytes. In the transmission sequence of the high-priority data packet and the low-priority data packet by the transmitting device, a first high-priority data packet A1 is transmitted first. Thereafter, the operating mode of the radio circuit 54 of the transmitting device is reversed from the transmitting mode to the receiving mode during a short pause, for example of the order of 150 μs. Therefore, the wireless circuit 54 of the transmitting device includes a Bluetooth transceiver. In the receive mode, the radio circuit 54 of the transmitting device monitors the communication link and verifies that the high priority data packet A1 arguably received correctly from the receiving device, i.e. the left ear hearing aid 10L in the present situation, is correctly received. Listen for an acknowledgment received signal to indicate. The receipt of this acknowledgment signal or packet is indicated by the packet or signal 207 labeled "Ack". Since the MD bit discussed above is set to "1" in the header 235 of the high priority data packet A1, the low priority data packet D is waiting and waiting for transmission. Thus, the transmitting device transmits the low priority data packet D210 which is waiting as shown, and after another short pause, a second acknowledgment signal or packet 209 is received as shown.

  At this point, the receiving device's Bluetooth LE controller 26L has successfully received both the high priority data packet A1 and the low priority data packet D. Thus, the Bluetooth LE controller 26L can safely abandon or skip the next subsequent connection event Ci2, which is otherwise used for retransmission of the high priority data packet A1, described in more detail below. . Thus, the wireless transceiver of the receiving device is not turned on during the second connection event Ci2, thereby saving considerable power compared to receiving and transmitting data packets.

  During the third connection event Ci3, a new high priority data packet A2 (215) is transmitted to the receiving device, which then returns an acknowledgment packet 211 labeled "Ack" to the transmitting device. Acknowledgment for reliable reception. In the header 235 of the second high priority data packet A2, the MD bit can be set to "0" to indicate that there is no low priority data packet D waiting. At this point, the Bluetooth LE controller 26L of the receiving device has reliably received the high-priority data packet A2, and by examining the MD bit in the header of the packet A2, the waiting low-priority data packet D2 is received. It can be concluded that there is no. Accordingly, the Bluetooth LE controller 26L thus abandons or skips the subsequent connection event Ci4 (not shown).

  FIG. 3 shows another exemplary timing diagram 300 illustrating a novel method of wirelessly communicating data sets having different priorities. FIG. 3 illustrates that the transmission of individual data packets or data sets from a transmitting device to a receiving device sometimes fails due to some coherent electromagnetic noise in the associated data channel, eg, the wireless communication link 12L of FIG. Indicates the operating state.

  As described above in connection with FIG. 2, successive connection events of the wireless communication link are indicated by Ci1, Ci2, Ci3, Ci4, etc. along the time axis t. Those skilled in the art will appreciate that adjacent connection events shown, such as Ci1 and Ci2, can be separated according to the Bluetooth LE protocol by a fairly long sleep or inactivity period, eg, up to 4 seconds.

  In FIG. 3, the transmission sequence of the high-priority data packets A1, A2 and the low-priority data packet D by the transmitting device starts from the transmission of the first high-priority audio data packet A1. Thereafter, the transmitting device switches its operation to the receiving mode described above and monitors the communication link for acknowledgments of the received signal or package transmitted by the receiving device, ie the left ear hearing aid 10L. In the illustrated communication sequence, the transmission of the high-priority data packet A1 within the connection event Ci1 is successful, and the receiving device transmits an acknowledgment signal or packet Ack. No low-priority data packet D is in a waiting state and waiting for transmission, and therefore, in the header of the high-priority data packet A1, the above-mentioned MD bit is indicated in the data packet A1 of FIG. = 0, as shown in FIG.

  Since high priority data has been received and there is no low priority data packet D waiting, the receiver skips the next connection event Ci2, thereby reducing power consumption in the receiver.

  Within the third connection event Ci3, the high-priority data packet A2 is transmitted for the first time with limited success. The receiving device receives the data packet, but a transmission error is detected, for example, in a CRC, and the receiving device sends an acknowledgment signal or a data packet "Nack", possibly in the same connection event Ci3. The MD bit described above is set to "1" to request a retransmission of the data packet. Therefore, the data packet A2 is retransmitted in the same connection event Ci3, but in this example, a transmission error is detected in the receiving device, and the result is the same as the previous one. Optionally, to save power, the receiving device does not transmit a second "Nack" signal or packet.

  Thereafter, a first retransmission in a subsequent connection event Ci4 is performed, this time the receiving device has successfully received the data packet A2, and thus the receiving device transmits an acknowledgment signal or packet to the transmitting device. I do. As indicated by "MD = 0" in the data packet A2 of FIG. 3, there is no low priority data packet D in the waiting state.

  If a transmitted data packet is lost, the receiving device does not transmit any signal, such as a "Nack" signal, and if there is no signal from the receiving device, the connection event preferably terminates to save power. Therefore, preferably, no retransmission is performed in the same connection event in which the first transmission of the data packet was performed.

  FIG. 4 shows another exemplary timing diagram 400 illustrating a novel method of wirelessly communicating data sets having different priorities. In this case, the maximum number of retransmissions of a high priority data packet within a new connection event is set to one. FIG. 4 illustrates that transmission of individual data packets or data sets from a transmitting device to a receiving device may sometimes fail due to some coherent electromagnetic noise in the associated data channel, for example, FIG. Of the wireless communication link 12L.

  Similar to FIG. 3, successive connection events of the wireless communication link are indicated along the time axis t by Ci1, Ci2, Ci3, Ci4, etc. Those skilled in the art will appreciate that adjacent connection events shown, such as Ci1 and Ci2, can be separated according to the Bluetooth LE protocol by a fairly long sleep or inactivity period, eg, up to 4 seconds.

  Within the first connection event Ci1, the high priority data packet A1 is transmitted for the first time, with limited success. The receiving device receives the data packet, but a transmission error is detected, for example, in the CRC, and the receiving device sends a negative acknowledgment signal or a data packet "Nack", possibly in the same connection event Ci1. The MD bit discussed above is set to "1" to request a retransmission of data packet A1. Thus, the data packet A1 is retransmitted in the same connection event Ci1, but in this example a transmission error is detected in the receiving device, again with the same result as before. Optionally, to save power, the receiving device does not transmit a second "Nack" signal or packet.

  Thereafter, a first retransmission in a subsequent connection event Ci2 is performed, but subsequently a transmission error is detected in the receiving device and a negative acknowledgment signal or data packet "Nack" is transmitted, possibly The MD bit discussed above is set to "1" to request a retransmission of data packet A1 within the same connection event Ci2. Thus, the data packet A1 is retransmitted in the same connection event Ci2, but again results in a transmission error being detected in the receiving device.

  As a result, the data packet A1 is flushed due to a timeout, and the transmitting device acquires the next high-priority data packet A2 and transmits it in the connection event Ci3. The transmission is successful and the receiving device acknowledges receipt of data packet A2. There is no data packet with lower priority waiting for transmission in the transmitting device, so that the MD bit is set to "0" in the header of the second high priority data packet A2; Thus, the receiving device skips the fourth connection event Ci4, thereby saving power.

  In the illustrated example, the predetermined maximum number of retransmissions of a high priority data packet in a new connection event is 1, but a larger maximum value, for example, 2, 3, or 4, may be selected. . Also, the transmitting device is configured to retransmit the low priority data packet until an acknowledgment of reception is received from the receiving device, that is, without limiting the number of retransmissions to the selected maximum number. Is also good.

  Restricting the number of retransmissions of a specific high priority data packet to the selected maximum number facilitates maintaining the real time characteristics of the data packet received by the receiving device. If the number of retransmissions of a particular high-priority data packet reaches a predetermined maximum without success, the transmitting device may flush the particular high-priority data packet or Overwrite the packet with a new high priority data packet representing, for example, the current audio content, and then transmit the new high priority data packet. The loss of the former high priority data packet can be concealed by the receiving device by a suitable packet loss concealment algorithm executed, for example, by the hearing loss processor 24L of the left hearing aid.

  If a transmitted data packet is lost, the receiving device does not transmit any signal, such as a "Nack" signal, and if there is no signal from the receiving device, the connection event preferably terminates to save power Therefore, preferably, no retransmission is performed within the same connection event that the data packet was originally transmitted.

  In the timing diagram of FIG. 5, in the connection event Ci1, the transmission of the high-priority data packet A1 is successful, and the receiving device transmits the acknowledgment signal or the packet “Ack” to the transmitting device, thereby ensuring reliable reception. Give an affirmative response. The MD bit is set to "1" in the header of the first high-priority data packet A1, indicating that a new low-priority data packet D1 is waiting to be transmitted to the receiving device. . The transmitting device subsequently transmits the low priority data packet D1 during the same connection event Ci1. The transmission is successful and the receiving device acknowledges the reception. Since the receiving device has successfully received both the high-priority data packet A1 and the low-priority data packet D1, it skips the second connection event Ci2, thereby saving the power of the receiving device.

  In connection event Ci3, the transmission of the second high-priority data packet A2 to the receiving device is successful, and the receiving device acknowledges the reception. The MD bit is set to "1" in the header of the second high-priority data packet A2, indicating that a new low-priority data packet D2 is waiting for transmission to the receiving device. . The transmitting device subsequently transmits the low priority data packet D2 during the same connection event Ci3. The transmission of the second low priority data packet D2 is unsuccessful and the receiving device does not acknowledge the reception, as indicated by the dashed box "Nack". When the data packet D2 is lost, the receiving device does not transmit anything to the transmitting device, and when the receiving device receives the data packet D2 but detects a transmission error, the receiving device transmits a "Nack" signal. May be.

  Since there is no high-priority data set or packet waiting to be transmitted to the receiving device, the transmitting device subsequently proceeds to a second data packet D2 having a low priority during the fourth connection event Ci4. Retransmitted, this time successfully.

  In FIG. 6, the transmission of the high priority data packet A1 in the connection event Ci1 is successful and the receiving device acknowledges the reliable reception by transmitting an acknowledgment signal or packet "Ack" to the transmitting device. I do. In the header of the first high-priority data packet A1, the MD bit is set to "1", indicating that a new low-priority data packet D1 is waiting for transmission to the receiving device. , The transmitting device subsequently transmits the low priority data packet D1 during the same connection event Ci1. The transmission of the low priority data packet D1 fails, and the receiving device does not acknowledge the reception, as indicated by the dashed box "Nack". When the data packet D1 is lost, the receiving device does not transmit anything to the transmitting device, and when the receiving device receives the data packet D1 but detects a transmission error, the receiving device transmits a "Nack" signal. May be.

  Since there is no high-priority data set or packet waiting to be transmitted to the receiving device, the transmitting device subsequently replays the second data packet D1 having a low priority during the second connection event Ci2. The transmission is performed, but the transmission fails within the connection event Ci2. Within the connection event Ci3, the transmission of the new high priority data packet A2 is not successful and is retransmitted as already explained above. After the successful transmission of the high-priority data packet A2, the transmission of the low-priority data packet D1 to the receiving device in the connection event Ci4 is finally successful.

  FIG. 7 shows that the priority of data packets waiting for retransmission increases as a function of, for example, the number of failed retransmission attempts, and the priority of data packets waiting for retransmission has a higher priority. Indicates that a higher priority may be obtained than a data packet having

  In FIG. 7, in the connection event Ci1, the transmission of the high priority data packet A1 is successful and the receiving device acknowledges the reliable reception by sending an acknowledgment signal or packet "Ack" to the transmitting device. I do. The MD bit is set to "1" in the header of the first high-priority data packet A1, indicating that a new low-priority data packet D1 is waiting to be transmitted to the receiving device. . The transmitting device subsequently transmits the low priority data packet D1 during the same connection event Ci1. The transmission of the low priority data packet D1 fails, and the receiving device does not acknowledge the reception, as indicated by the dashed box "Nack". When the data packet D1 is lost, the receiving device does not transmit anything to the transmitting device, and when the receiving device receives the data packet D1 but detects a transmission error, the receiving device transmits a "Nack" signal. May be.

  After the failure of the retransmission, the priority of the data packet D1 is set to the highest value, and the transmitting device subsequently proceeds during the second connection event Ci2 to the first data having the high priority at this time. The packet D1 is retransmitted, but the transmission fails within the connection event Ci2. In connection event Ci3, transmission of data packet D1 fails again, but in connection event Ci4, transmission of D1 to the receiving device eventually succeeds. Further, within the same connection event Ci4, the transmission of the new high-priority data packet A2 to the receiving device is successful.

  FIG. 8 shows a flowchart of an example of the new method.

  The illustrated method 500 may be used to transmit audio, such as voice and / or music, from a transmitting device housed in, for example, a smartphone configured to be compliant with the Bluetooth LE standard protocol, such as a hearing aid or headphones or another. It can be used to stream to a receiving device housed in a hearing device.

  According to the illustrated method 500, when streaming is requested, the streamed audio data is packed into audio data packets, also referred to as audio data sets, throughout this disclosure, according to the Bluetooth LE standard protocol. The audio data packets are given a high priority so that the transmission of the audio data packets is not interrupted by the transmission of other data, such as control data, e.g. a command to increase the volume of the hearing device .

Audio data packets are transmitted in order by the following steps.
510: establishing one connection event of a series of consecutive connection events according to Bluetooth LE standard protocol;
520: A high priority is given to at least one audio data packet or audio data set in the streamed audio data packet or audio data set, and the transmitting device receives the high priority from the transmitting device. Sending as if receiving;
530: Waiting for acknowledgment of reception from the receiving device.
540: If there is no acknowledgment of reception from the receiving device 520: Retransmitting at least one audio data packet or audio data set.
550: If there is an acknowledgment of reception from the receiving device,
560: Lower than the priority given to the audio data packet when the transmitting device would have retransmitted at least one audio data packet or audio data set without an acknowledgment Transmitting a second data packet or data set having a second priority from the transmitting device to the receiving device.

  Preferably, in order to ensure high fidelity or at least acceptable quality of the sound generated based on the streamed audio, the audio data packets of the streamed audio have a high priority, whereby , Ensuring that audio data packets are transmitted before transmitting other types of data sets having lower priorities.

  The method may further include allocating an L2CAP channel to transmission of the audio data set, for example, allocating one L2CAP channel to control data associated with the audio data set and / or By assigning an L2CAP channel to a first audio data set and possibly another L2CAP channel to a second audio data set.

The following three fixed L2CAP channels can be allocated for audio transmission.
1) Control data (start, stop, codec negotiation, etc.)
2) Left audio data 3) Right audio data

  For a device capable of receiving one audio stream (left or right), for example a hearing aid, only channels 1) and 2) or channels 1) and 3) are used for that device. In a device with integrated stereo functionality, such as a stereo headset, all three channels are used. The audio data set may be unidirectional or bidirectional depending on the application, and the control data channel should allow negotiation on that point.

FIG. 9 shows a flowchart of another example 500 'of the novel method, which includes the following steps in addition to the steps of the method 500 shown in FIG.
In step 520: in at least one data packet, whether a data set having a second priority is waiting to be transmitted to a receiving device, eg, encoded into data bytes or data bits Including the information.
570: checking whether a data set having the second priority is waiting for transmission to the receiving device;
580: Between the transmitting device and the receiving device to transmit the second data set having the second priority if there is no data set having the second priority waiting to be transmitted to the receiving device Stopping the establishment of the connection.
590: If the data set with the second priority is waiting for transmission to the receiving device,
560: Lower than the priority given to the audio data packet when the transmitting device would have retransmitted at least one audio data packet or audio data set without an acknowledgment Transmitting a second data packet or data set having a second priority from the transmitting device to the receiving device.

FIG. 10 shows a flowchart of another example 500 '' of the novel method that includes the following steps in addition to the steps of the method 500 shown in FIG.
Step 510: setting a counter of the number of retransmission attempts of the audio data packet transmitted in Step 520 to zero.
Step 520: increment the counter by one.
540: If there is no acknowledgment of reception from the receiving device,
600: checking the value of the counter of the number of retransmission attempts of the audio data packet.
610: If the value is less than 2, 520: Increment the counter by 1 and retransmit at least one audio data packet or audio data set.
620: If the value is equal to 2, 560: If the transmitting device would have retransmitted at least one audio data packet or audio data set without an acknowledgment, the audio data packet Transmitting a second data packet or data set having a second priority lower than the given priority from the transmitting device to the receiving device.

  Additional method steps 600, 610, and 620 may be added to the method 500 ', as shown in FIG. 11, which shows a flowchart of another example 500 "" of the new method.

  The allowable number of retransmission attempts for other types of data may be different from one and may be unlimited, i.e., a maximum different from two, no maximum, or an infinite maximum may be different. May be assigned to this type of data.

  For different types of data, the predetermined maximum value for retransmission attempts may be different, for example, the audio data set may have a maximum value of 2, while the audio data set has a priority. The maximum of a data set having a lower priority than degrees may have a higher maximum.

Advantageously, the novel method shown facilitates the transmission of audio data packets or sets using Bluetooth LE by utilizing the limited functionality of Bluetooth LE control and link layer enhancements. For example, operations related to security and link setup are performed as specified in the Bluetooth Core Specification.

Advantageously, the novel method shown facilitates the transmission of audio data packets or sets using Bluetooth LE by utilizing the limited functionality of Bluetooth LE control and link layer enhancements. For example, operations related to security and link setup are performed as specified in the Bluetooth Core Specification.
The features of the technology described in the specification are listed.
(Feature 1)
A method of wirelessly communicating a data set, comprising:
Transmitting a first data set of a first data category from a transmitting device to a receiving device for receiving;
Retransmitting the first data set in the absence of an acknowledgment of reception from the receiving device;
The first data category, if there is the acknowledgment of the reception from the receiving device, the transmitting device and the receiving device would have been connected for the retransmission without the acknowledgment; Transmitting a second data set of a second data category different from the transmitting device to the receiving device.
(Feature 2)
The method of claim 1, wherein the first data set has a first priority and the second data set has a second priority lower than the first priority.
(Feature 3)
Whether a data set of the second data set is waiting for transmission to the receiving device, and transmitting a signal from the transmitting device to the receiving device;
If there is no data set of the second data set waiting to be transmitted to the receiving device, the transmitting device and the receiving device for transmitting the data set of the second data set; Ceasing to establish the connection between the two.
(Feature 4)
The method of claim 2, wherein information regarding whether a data set of the second data set is waiting for transmission to the receiving device is encoded into a single data bit.
(Feature 5)
A method according to any of the preceding claims, comprising transmitting and receiving data according to the Bluetooth Low Energy standard.
(Feature 6)
5. The method of Feature 4, comprising assigning an L2CAP channel for transmission of the audio data set.
(Feature 7)
The method of claim 5, comprising allocating one L2CAP channel to control data associated with the audio data set.
(Feature 8)
7. The method according to feature 5 or 6, comprising allocating one L2CAP channel to the first audio data set.
(Feature 9)
The method of claim 7, comprising assigning another L2CAP channel to the second audio data set.
(Feature 10)
The audio data set, provided that the number of retransmission attempts of the same audio data set is less than a predetermined maximum in the absence of an acknowledgment of reception of the audio data set from the receiving device; 10. The method according to any of features 4 to 8, comprising the step of retransmitting
(Feature 11)
The method of Feature 9, wherein the maximum value is 2.
(Feature 12)
11. The method according to Feature 9 or 10, wherein different types of data have different predetermined maximum values for retransmission attempts.
(Feature 13)
A transmission delay difference between at least two different receivers connected to receive different audio data sets, at least one receiver configured to receive the audio data set from the transmitter; 13. A method according to any of features 1 to 12, comprising transmitting synchronization data, including timing information related to.
(Feature 14)
The method of claim 12, comprising determining synchronization data based on a ping transmission from the transmitting device to at least two different receiving devices.
(Feature 15)
14. The method of Feature 13, comprising ping transmission utilizing an L2CAP control channel.
(Feature 16)
A hearing device comprising a communication controller adapted to operate according to the method of any of features 1 to 15.
(Feature 17)
The hearing device of Feature 15, wherein the hearing device is a hearing aid.

Claims (17)

A method of wirelessly communicating a data set, comprising:
Transmitting a first data set of a first data category from a transmitting device to a receiving device for receiving;
Retransmitting the first data set in the absence of an acknowledgment of reception from the receiving device;
The first data category, if there is the acknowledgment of the reception from the receiving device, the transmitting device and the receiving device would have been connected for the retransmission without the acknowledgment; Transmitting a second data set of a second data category different from the transmitting device to the receiving device.   The method of claim 1, wherein the first data set has a first priority and the second data set has a second priority lower than the first priority. Whether a data set of the second data set is waiting for transmission to the receiving device, and transmitting a signal from the transmitting device to the receiving device;
If there is no data set of the second data set waiting to be transmitted to the receiving device, the transmitting device and the receiving device for transmitting the data set of the second data set; Ceasing to establish the connection between the two.   3. The method of claim 2, wherein the information as to whether a data set of the second data set is waiting for transmission to the receiving device is encoded into a single data bit.   The method according to any of the preceding claims, comprising transmitting and receiving data according to the Bluetooth Low Energy standard.   5. The method of claim 4, comprising assigning an L2CAP channel for transmission of the audio data set.   The method of claim 5, comprising allocating one L2CAP channel to control data associated with the audio data set.   The method according to claim 5 or 6, comprising the step of allocating one L2CAP channel to the first audio data set.   The method of claim 7, comprising allocating another L2CAP channel to the second audio data set.   The audio data set, provided that the number of retransmission attempts of the same audio data set is less than a predetermined maximum in the absence of an acknowledgment of reception of the audio data set from the receiving device; 9. A method according to any of claims 4 to 8, comprising the step of retransmitting.   10. The method of claim 9, wherein the maximum value is 2.   11. The method according to claim 9 or 10, wherein different types of data have different predetermined maximum values for retransmission attempts.   A transmission delay difference between at least two different receivers connected to receive different audio data sets, at least one receiver configured to receive the audio data set from the transmitter; 13. A method according to any one of the preceding claims, comprising transmitting synchronization data, including timing information related to.   The method of claim 12, comprising determining synchronization data based on a ping transmission from the transmitting device to the at least two different receiving devices.   14. The method according to claim 13, comprising ping transmission using an L2CAP control channel.   A hearing device comprising a communication controller adapted to operate according to the method of any one of claims 1 to 15.   The hearing device according to claim 15, wherein the hearing device is a hearing aid.