Techniques for dynamically adjusting retransmission opportunities within connected isochronous streams

Abstract

Methods, systems, and devices are described for techniques for dynamically adjusting retransmission opportunities within connected isochronous flow (CIS). In some aspects, a first wireless device and a second wireless device may support one or more dynamic adjustments or "in-operation" adjustments to one or more CIS settings according to link quality between the first wireless device and the second wireless device. For example, a first wireless device and a second wireless device may link together a number of transmission opportunities available for retransmission within a given isochronous (ISO) interval with link quality between the first wireless device and the second wireless device. The link quality may be linked together or associated with a modulation and coding scheme (MCS) of the link. As such, the first wireless device and the second wireless device may link the dynamic change in MCS with the dynamic change in retransmission opportunities.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 17 / 949,032, filed by TURNER et al. on September 20, 2022, entitled “TECHNIQUES FORDYNAMICALLY ADJUSTING RETRANSISSION OPPORTUNITIES WITHIN A CONNECTEDISHOCHRONOUS STREAM,” which is assigned to the assignee of this application and the entire contents of which are expressly incorporated herein by reference. Background Art

[0003] The following relates to wireless communications, including techniques for dynamically adjusting retransmission opportunities within a connected isochronous stream (CIS).

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems can be multiple access systems that can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). A wireless network (e.g., a wireless local area network (WLAN) such as a Wi-Fi (i.e., Institute of Electrical and Electronics Engineers (IEEE) 802.11) network) may include an access point (AP) that can communicate with one or more wireless devices or mobile devices. The AP can be coupled to a network such as the Internet and can enable mobile devices to communicate via the network (or communicate with other devices coupled to the access point). A wireless device can communicate bidirectionally with a network device. For example, in a WLAN, a device can communicate with an associated AP via a downlink (e.g., a communication link from an AP to a device) and an uplink (e.g., a communication link from a device to an AP). A wireless personal area network (PAN), which may include a Bluetooth connection, can provide a short-range wireless connection between two or more paired wireless devices. For example, a wireless device such as a cellular phone can utilize wireless PAN communication to exchange information such as audio signals with a wireless headset. Summary of the invention

[0005] The described techniques relate to improved methods, systems, devices, and apparatuses that support techniques for dynamically adjusting retransmission opportunities within a connected isochronous stream (CIS). In general, the described techniques provide for dynamic or "on-the-fly" adjustment of one or more CIS settings based on link quality between a first wireless device and a second wireless device. In some examples, the first wireless device and the second wireless device may support a configuration according to which the wireless devices associate the number of transmission opportunities available for retransmission within a given isochronous (ISO) interval with the link quality between the first wireless device and the second wireless device (which may be associated with a modulation and coding scheme (MCS) of the link). In such an example, as link quality deteriorates (e.g., as the MCS decreases), the first wireless device and the second wireless device may increase the number of transmission opportunities available for retransmission, and as link quality improves (e.g., as the MCS increases), the first wireless device and the second wireless device may reduce the number of transmission opportunities available for retransmission.

[0006] A method for wireless communication at a first wireless device is described. The method may include sending or receiving a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmissions via a CIS and a respective MCS of the CIS, detecting a change to the MCS of the CIS during a first ISO interval of the CIS, adjusting the number of transmission opportunities allocated for retransmissions for a second ISO interval of the CIS based on the detected change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration, and sending or receiving one or more audio data packets with a second wireless device during the second ISO interval based on the adjusted number of transmission opportunities allocated for retransmissions.

[0007] An apparatus for wireless communication at a first wireless device is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to send or receive a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmissions via a CIS and a corresponding MCS of the CIS, detect a change to the MCS of the CIS during a first ISO interval of the CIS, adjust the number of transmission opportunities allocated for the retransmissions for a second ISO interval of the CIS based on the detected change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration, and send or receive one or more audio data packets using a second wireless device during the second ISO interval based on the adjusted number of transmission opportunities allocated for retransmissions.

[0008] Another apparatus for wireless communication at a first wireless device is described. The apparatus may include: means for sending or receiving a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmissions via a CIS and a respective MCS of the CIS; means for detecting a change to the MCS of the CIS during a first ISO interval of the CIS; means for adjusting the number of transmission opportunities allocated for retransmissions for a second ISO interval of the CIS based on the detected change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration; and means for sending or receiving one or more audio data packets with a second wireless device during the second ISO interval based on the adjusted number of transmission opportunities allocated for retransmissions.

[0009] A non-transitory computer-readable medium storing code for wireless communication at a first wireless device is described. The code may include instructions executable by a processor to: send or receive a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmissions via a CIS and a respective MCS of the CIS; detect a change to the MCS of the CIS during a first ISO interval of the CIS; adjust the number of transmission opportunities allocated for retransmissions for a second ISO interval of the CIS based on the detection of the change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration; and send or receive one or more audio data packets with a second wireless device during the second ISO interval based on the adjusted number of transmission opportunities allocated for retransmissions.

[0010] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, adjusting the number of transmission opportunities that can be allocated for retransmissions can include operations, features, components, or instructions for increasing the number of transmission opportunities that can be allocated for retransmissions when the MCS decreases from a relatively higher MCS to a relatively lower MCS, and decreasing the number of transmission opportunities when the MCS increases from a relatively lower MCS to a relatively higher MCS.

[0011] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, adjusting the number of transmission opportunities that can be allocated for retransmissions can include operations, features, components, or instructions for: reducing a burst number (BN) associated with the CIS as the MCS decreases from a relatively higher MCS to a relatively lower MCS, wherein reducing the BN can be associated with an increase in the number of transmission opportunities that can be allocated for retransmissions; and increasing the BN associated with the CIS as the MCS increases from a relatively lower MCS to a relatively higher MCS, wherein increasing the BN can be associated with a decrease in the number of transmission opportunities that can be allocated for retransmissions.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, adjusting the number of transmission opportunities that can be allocated for retransmissions can include operations, features, components, or instructions for: increasing a refresh timeout (FT) associated with the CIS as the MCS decreases from a relatively higher MCS to a relatively lower MCS, wherein increasing the FT can be associated with an increase in the number of transmission opportunities that can be allocated for retransmissions; and decreasing the FT associated with the CIS as the MCS increases from a relatively lower MCS to a relatively higher MCS, wherein decreasing the FT can be associated with a decrease in the number of transmission opportunities that can be allocated for retransmissions.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, a BN associated with a CIS, an FT associated with a CIS, and a packet size may be tuned for each MCS in a set of multiple MCSs, and the BN, FT, and packet size may be dynamically changed in response to changes to the MCS.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: incrementing a protocol data unit (PDU) sequence number by a fixed value after a first ISO interval, wherein the first ISO interval may be associated with a first BN; and incrementing the PDU sequence number by the fixed value after a second ISO interval, wherein the second ISO interval may be associated with a second BN that may be different from the first BN.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the first wireless device increments the PDU sequence number by the fixed value after each ISO interval based on adjusting the number of transmission opportunities that can be allocated for retransmissions across ISO intervals, regardless of an actual BN associated with the ISO interval.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, for each MCS in a set of multiple MCSs, a mapping indicates a corresponding number of transmission opportunities that can be allocated for retransmission, timing information associated with an adjustment to the corresponding number of transmission opportunities that can be allocated for retransmission, and a size of the PDU.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the control message further indicates, for each MCS, a number of sub-events or a number of sub-intervals during the ISO interval.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for indicating a size of a PDU for a length hardening function at a first wireless device and a second wireless device, and at each transmission opportunity of an ISO interval, reading an amount of data equal to the size of the PDU based on the size of the PDU indicated to the length hardening function, so that each PDU received by the first wireless device can have the same size, wherein the size of the PDU indicated to the length hardening function overrides a second size indicated by a header of the PDU.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: using a majority voting algorithm to handle two or more failed attempts to decode a single PDU, wherein the majority voting algorithm may be associated with a size indicated to a length hardening function, and wherein, if the majority voting algorithm detects a difference in length fields across two or more failed attempts to decode the single PDU, the majority voting algorithm uses the size indicated to the length hardening function to correct the PDU.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the control message indicates a mapping between a corresponding number of transmission opportunities that can be allocated for the retransmission and a corresponding MCS for each of two different communication directions, and the mapping includes a first mapping for communication from a central device to a peripheral device and a second mapping for communication from the peripheral device to the central device.

[0021] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, a mapping entry associated with the second mapping may have a zero length when a reverse channel link from the peripheral device to the central device may be disabled and may have a non-zero length when a reverse channel link from the peripheral device to the central device may be enabled, and sending or receiving a control message dynamically enables or disables the reverse channel link based on whether the mapping entry associated with the second mapping may have a zero length or a non-zero length.

[0022] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending or receiving one or more audio data packets during the second ISO interval may include operations, features, components, or instructions for sending one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets to a second wireless device based on a number of transmission opportunities that may be allocated for retransmissions, wherein the first wireless device may be configured as a transmitting device and the second wireless device may be configured as a receiving device.

[0023] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending or receiving one or more audio data packets during the second ISO interval may include operations, features, components, or instructions for receiving one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets from a second wireless device based on a number of transmission opportunities that may be allocated for retransmissions, wherein the first wireless device may be configured as a receiving device and the second wireless device may be configured as a transmitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 An example of a wireless communication system supporting techniques for dynamically adjusting retransmission opportunities within a connected isochronous stream (CIS) in accordance with aspects of the present disclosure is shown.

[0025] Figure 2 An example of a signaling diagram supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0026] Figure 3 An example of a communication timeline supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0027] Figure 4 An example of a signaling diagram supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0028] Figure 5 and Figure 6 An example of a process flow supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0029] Figure 7 and Figure 8 A block diagram of a device supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0030] Fig. 9 A block diagram of an I / O controller supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0031] Fig.10 A diagram of a system including devices supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown.

[0032] Fig.11 A flow chart illustrating a method of supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0033] Some current wireless Bluetooth connections, such as an isochronous stream (CIS) connection between a central device (e.g., a cell phone) and one or more peripheral devices (e.g., a wireless headset), may follow a relatively strict timing protocol that is set during the initial setup configuration. For example, when setting up the CIS, the two devices may negotiate how many transmission opportunities are allocated to new data and how many transmission opportunities are allocated to any potential retransmissions, as well as other settings, and the two devices may follow the negotiated settings for the entire established CIS. Therefore, in order to change the timing protocol of the CIS, the two devices may reconfigure the link, which may enable renegotiation between the two devices and any other devices currently sharing the same link or spectrum. Such reconfiguration and renegotiation may introduce latency, be prone to failure, and potentially have an adverse effect on other devices sharing the same link or spectrum.

[0034] In some implementations, the first wireless device and the second wireless device may support one or more dynamic or "on-the-fly" adjustments to one or more CIS settings based on the quality of a link between the first wireless device and the second wireless device. In some examples, the first wireless device and the second wireless device may support a configuration according to which the wireless devices tie or associate the number of transmission opportunities available for retransmissions within a given isochronous (ISO) interval with the quality of the link between the first wireless device and the second wireless device (which may be tied or associated with a modulation and coding scheme (MCS) of the link). In such an example, as the link quality deteriorates (e.g., as the MCS decreases), the first wireless device and the second wireless device may increase the number of transmission opportunities available for retransmissions, and as the link quality improves (e.g., as the MCS increases), the first wireless device and the second wireless device may decrease the number of transmission opportunities available for retransmissions.

[0035] The first wireless device and the second wireless device may control the number of transmission opportunities available for retransmission by controlling, switching, or configuring one or more parameters associated with the CIS. Such one or more parameters may include a burst number (BN) or a refresh timeout (FT), or both. For example, the first wireless device and the second wireless device may dynamically update the BN or FT, or both, across ISO intervals within the CIS to dynamically adjust the number of transmission opportunities available for retransmission across the ISO intervals. In addition, the first wireless device and the second wireless device may update the BN or FT, or both, across ISO intervals without affecting other timing-related aspects of the CIS, such as without changing the duration of the ISO intervals within the CIS.

[0036] Certain aspects of the subject matter described herein may be implemented to achieve one or more of the following potential advantages. For example, based on implementing dynamic or "on-the-fly" updates of the BN or FT or both of the CIS across different ISO intervals without changing the timing-related information associated with the CIS, the wireless device can more flexibly adapt the ratio between new data transmissions and retransmissions based on the current or most recent link conditions without reconfiguring the entire CIS or interrupting communications between other devices sharing the same link or spectrum. Therefore, the wireless device can use more transmission opportunities for new data transmissions in low-interference scenarios (e.g., when the link quality is relatively good), and can use more transmission opportunities for retransmissions in high-interference scenarios (e.g., when the link quality is relatively poor). In other words, the wireless device can achieve a balance or control trade-off between data rate and robustness (e.g., reliability) depending on the link conditions. Therefore, the wireless device can experience higher data rates, higher spectral efficiency, and lower latency, among other benefits.

[0037] Aspects of the present disclosure are initially described in the context of a multimedia system. Aspects of the present disclosure are additionally illustrated and described with reference to signaling diagrams, communication timelines, and process flows. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to techniques for dynamically adjusting retransmission opportunities within a CIS.

[0038] Figure 1 An example of a wireless communication system 100 that supports techniques for dynamically adjusting retransmission opportunities within a CIS according to various aspects of the present disclosure is shown. In some examples, the wireless communication system 100 may include or refer to a wireless personal area network (PAN), a wireless local area network (WLAN, Wi-Fi network) configured according to various aspects of the present disclosure. The wireless communication system 100 may include an access point (AP) 105 that implements WLAN communication (e.g., Wi-Fi communication) and / or Bluetooth communication, a device 110 (e.g., which may be referred to as a source device, a central device, etc.) and a paired device 115 (e.g., which may be referred to as a host device, a peripheral device, etc.). For example, the device 110 may include a cellular phone, a user equipment (UE) wireless station (STA), a mobile station, a personal digital assistant (PDA), other handheld devices, a netbook, a notebook computer, a tablet computer, a laptop computer, or some other suitable term. The paired device 115 may include a Bluetooth-enabled device that is capable of pairing with other Bluetooth-enabled devices (e.g., such as device 110), which may include wireless audio devices (e.g., headphones, earbuds, speakers, receivers, headsets), display devices (e.g., TVs, computer monitors), microphones, meters, valves, etc.

[0039] Bluetooth communication may refer to a short-range communication protocol and may be used to connect and exchange information between a device 110 and a paired device 115 (e.g., between a mobile phone, a computer, a digital camera, a wireless headset, a speaker, a keyboard, a mouse or other input peripherals and similar devices). A Bluetooth system (e.g., aspects of the wireless communication system 100) may be organized using a central-peripheral relationship using a time division duplex protocol with, for example, defined time slots of 625 microseconds, where transmissions alternate between a central device (e.g., device 110) and one or more peripheral devices (e.g., paired devices 115). In some examples, device 110 may generally refer to a central device, and paired devices 115 may refer to peripheral devices in the wireless communication system 100. Thus, in some examples, a device may be referred to as a device 110 or a paired device 115 based on the device's Bluetooth role configuration. That is, designating a device as a device 110 or a paired device 115 may not necessarily indicate a distinction in device capabilities, but may refer to or indicate the role that the device plays in the wireless communication system 100. Generally, device 110 may refer to a wireless communication device capable of wirelessly exchanging data signals with another device (e.g., paired device 115), and paired device 115 may refer to a device operating in a peripheral role, or to a short-range wireless communication device capable of exchanging data signals with device 110 (e.g., using the Bluetooth communication protocol).

[0040] Bluetooth-enabled devices may be compatible with certain Bluetooth profiles to use the desired services. A Bluetooth profile may refer to a specification regarding aspects of Bluetooth-based wireless communications between devices. That is, a profile specification may refer to an instruction set for using the Bluetooth protocol stack in a certain manner, and may include information such as a recommended user interface format, specific options and parameters at each layer of the Bluetooth protocol stack, and the like. For example, a Bluetooth specification may include individual profiles that define behaviors associated with each communication endpoint to implement a specific use case. Therefore, profiles may generally be defined based on a protocol stack that facilitates and allows interoperability between endpoint devices from different manufacturers by enabling applications to discover and use services that may be provided by other nearby Bluetooth-enabled devices. The Bluetooth specification defines device role pairs (e.g., roles for device 110 and paired device 115), which together form a single use case called a profile (e.g., for communication between device 110 and paired device 115). An example profile defined in the Bluetooth specification is a hands-free profile (HFP) for voice calls, in which one device (e.g., device 110) implements an audio gateway (AG) role, and another device (e.g., paired device 115) implements a hands-free (HF) device role. Another example is the Advanced Audio Distribution Profile (A2DP) for high-quality audio streaming, where one device (e.g., device 110) implements the audio source device (SRC) role and another device (e.g., paired device 115) implements the audio sink device (SNK) role.

[0041] For a commercial Bluetooth-enabled device that implements one role in a profile to function properly, another device that implements the corresponding role may be present within the radio range of the first device. For example, in order for an HF device such as a Bluetooth headset to function according to the Hands-Free Profile, a device that implements the AG role (e.g., a cellular phone) may have to be present within the radio range. Similarly, in order to stream high-quality mono audio or stereo audio according to A2DP, a device that implements the SNK role (e.g., a Bluetooth headset or Bluetooth speaker) may have to be within the radio range of a device that implements the SRC role (e.g., a stereo music player).

[0042] The Bluetooth specification defines a layered data transmission architecture and various protocols and processes to handle data transmitted between two devices implementing a specific profile use case. For example, various logical links can be used to support different application data transmission requirements, where each logical link is associated with a logical transmission with certain characteristics (e.g., flow control, confirmation mechanism, repetition mechanism, sequence numbering, scheduling behavior, etc.). The Bluetooth protocol stack can be divided into two parts: a controller stack including a timing-critical radio interface, and a host stack that handles high-level data. The controller stack can typically be implemented in a low-cost silicon device including a Bluetooth radio and a microprocessor. The controller stack can be responsible for establishing a connection link 125, such as an asynchronous connection-oriented link (or asynchronous connection-oriented connection), a synchronous connection-oriented (SCO) link (or SCO connection), an extended synchronous connection-oriented (eSCO) link (or eSCO connection), other logical transport channel links, etc.

[0043] In some examples, the controller stack can implement link management protocol (LMP) functions, low energy link layer (LELL) functions, etc. The host stack can generally be implemented as part of the operating system, or as an installable package on the operating system. The host stack can be responsible for logical link control and adaptation protocol (L2CAP) functions, Bluetooth network encapsulation protocol (BNEP) functions, service discovery protocol (SDP) functions, etc. In some examples, the controller stack and the host stack can communicate via a host controller interface (HCI). In other cases (for example, for integrated devices such as Bluetooth headsets), the host stack and the controller stack can run on the same microprocessor to reduce mass production costs. For such a hostless system, HCI can be optional and can be implemented as an internal software interface.

[0044] A connection link 125 can be established between two Bluetooth-enabled devices (e.g., between device 110 and paired device 115) and can provide communication or services (e.g., according to a certain Bluetooth profile). For example, a Bluetooth connection can be an eSCO connection for voice calls (e.g., which can allow for retransmission), an ACL connection for music streaming (e.g., A2DP), etc. For example, eSCO packets can be sent in predetermined time slots (e.g., 6 Bluetooth time slots per eSCO). When establishing a Bluetooth link, regular intervals between eSCO packets can be specified. eSCO packets to / from a specific device (e.g., paired device 115) are confirmed and can be retransmitted if not confirmed during the retransmission window. In addition, an ACL connection (A2DP profile) can be used to stream audio between device 110 and paired device 115. In some cases, an ACL connection can occupy 1, 3, or 5 Bluetooth time slots for data or voice. Other Bluetooth profiles supported by Bluetooth-enabled devices may include Bluetooth Low Energy (BLE) (e.g., providing significantly reduced power consumption and cost while maintaining similar communication range), Human Interface Device Profile (HID) (e.g., providing a low latency link with low power requirements), and the like.

[0045] In some examples, the device may be capable of both Bluetooth and WLAN communications. For example, WLAN and Bluetooth components may be co-located within the device so that the device can communicate according to Bluetooth and WLAN communication protocols, because each technology may provide different benefits or may improve the user experience under different conditions. In some examples, Bluetooth and WLAN communications may share the same medium, such as the same unlicensed frequency medium. In such examples, the device 110 may support WLAN communications via AP 105 (e.g., on communication link 120). AP 105 and associated devices 110 may represent a basic service set (BSS) or an extended service set (ESS). Each device 110 in the network may be able to communicate with each other through AP 105. In some cases, AP 105 may be associated with a coverage area, which may represent a basic service area (BSA).

[0046] Device 110 and AP 105 may communicate according to WLAN radio and baseband protocols for the physical layer and MAC layer from IEEE 802.11 and versions including, but not limited to, 802.11b, 802.11g, 802.11a, 802.11n, 802.11ac, 802.11ad, 802.11ah, 802.11ax, etc. In other implementations, peer-to-peer connections or ad hoc networks may be implemented within system 100, and devices may communicate with each other via communication links 120 (e.g., Wi-Fi direct connections, Wi-Fi tunneled direct link setup (TDLS) links, peer-to-peer communication links, other peer-to-peer connections, or group connections). AP 105 may be coupled to a network such as the Internet and may enable device 110 to communicate via the network (or to communicate with other devices 110 coupled to AP 105). Device 110 may communicate bidirectionally with network devices. For example, in a WLAN, device 110 may communicate with an associated AP 105 via a downlink (eg, a communication link from the AP 105 to the device 110 ) and an uplink (eg, a communication link from the device 110 to the AP 105 ).

[0047] In some examples, content, media, audio, etc. exchanged between device 110 and paired device 115 may originate from a WLAN. For example, in some examples, device 110 may receive audio from AP 105 (e.g., via WLAN communications), and device 110 may then relay or pass the audio to paired device 115 (e.g., via Bluetooth communications). In some examples, certain types of Bluetooth communications (e.g., such as high-quality or high-definition (HD) Bluetooth) may require enhanced quality of service. For example, in some examples, delay-sensitive Bluetooth traffic may have a higher priority than WLAN traffic.

[0048] In some implementations, the first wireless device and the second wireless device (which may be examples of the device 110, the paired device 115, or any combination thereof) may support one or more dynamic adjustments or "on-the-fly" adjustments to one or more CIS settings based on the link quality between the first wireless device and the second wireless device. In some examples, the first wireless device and the second wireless device may support a configuration or mapping according to which the wireless devices may link the number of transmission opportunities available for retransmissions within a given ISO interval to the link quality between the first wireless device and the second wireless device (which may be tied or associated with the MCS of the link). In such an example, as the link quality deteriorates (e.g., as the MCS decreases), the first wireless device and the second wireless device may increase the number of transmission opportunities available for retransmissions, and as the link quality improves (e.g., as the MCS increases), the first wireless device and the second wireless device may decrease the number of transmission opportunities available for retransmissions.

[0049] The techniques described herein can provide improvements in data rate, robustness, and reliability in variable deployment scenarios. In addition, the techniques described herein can provide benefits and enhancements for the operation of device 110. For example, by achieving a balance or trade-off between data rate and robustness (e.g., reliability) based on link conditions, the operating characteristics of AP 105, such as power consumption, processor utilization, and memory usage, can be reduced. The techniques described herein can also provide component-level efficiency or signaling-level efficiency or both to device 110 by reducing the latency associated with dynamically managing how many transmission opportunities can be used for retransmission-related processes within a given ISO interval of the CIS. In other words, the first wireless device and the second wireless device can be example devices (or include example devices), and perform techniques for dynamically configuring a Bluetooth CIS (such as a Bluetooth low energy (BLE) CIS) to improve robustness.

[0050] Figure 2 An example of a signaling diagram 200 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The signaling diagram 200 may implement or be implemented to implement aspects of the wireless communication system 100. For example, the signaling diagram 200 illustrates communication between a wireless device 205 and a wireless device 210 via a communication link 215, where the wireless device 205 and the wireless device 210 may be examples of multiple devices 110 or multiple paired devices 115, or one device 110 and one paired device 115, as shown in FIG. Figure 1 Shown and referenced Figure 1 as described.

[0051] In some aspects, one of the wireless device 205 and the wireless device 210 may be a central device, an initiator, a source device, or a first host and an initiating layer, and the other of the wireless device 205 and the wireless device 210 may be a peripheral device, a recipient, a sink device, or a second host and a responding layer. In some implementations, the wireless device 205 or the wireless device 210 or both may support a configuration or mapping according to which the number of transmission opportunities that may be used for retransmissions may be dynamically changed according to (e.g., as a result of) a change in the link quality of the communication link 215.

[0052] In some deployment scenarios, wireless device 205 and wireless device 210 may support low energy (LE) audio (e.g., as part of the Bluetooth standard), which may provide advantages associated with profiles or protocols, such as those associated with Advanced Audio Distribution Profile (A2DP) and Enhanced Synchronous Connection Oriented (eSCO) protocols, with real-time audio, lower power, and high-quality audio. However, in some aspects, LE audio may be associated with a rigid timing protocol, which may not be well suited to cope with changing wireless environments or changing user behavior. In other words, once a link (e.g., a Bluetooth wireless link) is established, configured, or established, the timing protocol associated with the link may be static (and inflexible) for the duration of the link.

[0053] When establishing a BLE wireless link, one or both of wireless device 205 and wireless device 210 may consider one or more potential tradeoffs associated with the link. One consideration may be associated with sharing a 2.4 GHz link with Wi-Fi bandwidth (e.g., one or more Wi-Fi devices may use the 2.4 GHz link in addition to wireless device 205 and wireless device 210). For example, a Wi-Fi device may have the option of using a 2.4 GHz link, a 5 GHz link, a 6 GHz link, or a 7 GHz link, or any combination thereof, which may constrain the Bluetooth device and the Wi-Fi device to time-share resources on the 2.4 GHz link.

[0054] In addition, even if the Wi-Fi device is operating using the 5 GHz link, the Bluetooth device and the Wi-Fi device can time-share resources on the 2.4 GHz link because the BLE link can be established to achieve bandwidth sharing with the Wi-Fi device regardless of which link the Wi-Fi device actually uses. This establishment constraint for achieving sharing can be adopted because as the Wi-Fi device roams (e.g., as the user roams with their phone), the Wi-Fi device (e.g., phone) may change between different APs 105 without control as to whether the 2.4 GHz link or the 5 GHz link is to be used. The device can reserve about 2 megabits per second (Mbps) of bandwidth for Wi-Fi to be used for the device to maintain a "good" (e.g., reliable, robust, etc.) connection to the Internet.

[0055] Another consideration may be the trade-off of quality versus robustness. For example, as a user uses a device (e.g., their phone), the user may change the way they interact with it (e.g., holding the device at arm's length, putting it down and walking away, putting it in the user's back pocket, etc.), and the error rate of the link between the device and, for example, an earphone or headset may change. For example, keeping the device at arm's length, putting it down and walking away, or putting it in the user's back pocket may increase the error rate of the link, resulting in more retransmissions. However, the air (OTA) time allocated to the Bluetooth link may be fixed (e.g., according to an initial setup) and may accommodate bandwidth for new data as well as for retransmissions. Accordingly, because the OTA time is fixed, an increase in retransmissions may reduce the amount of bandwidth that may be used by an audio stream (e.g., an audio stream of a new audio data packet).

[0056] Additionally, another consideration may be that the user may use a voice channel while using an application (e.g., while playing a video game). However, when the link is initially established, it may be unknown whether such a voice channel is to be used. Thus, the wireless device 205 or the wireless device 210 or both may reserve bandwidth for such a voice channel during the initial establishment in case it is used in the future. Thus, if the user wishes to use the voice channel at some point after the initial link is established, sufficient bandwidth for the voice channel may be available, but when the user is not using the voice channel, the bandwidth may not be used.

[0057] In some Bluetooth profiles (such as A2DP), the packet size and the interval between packets can be adjusted dynamically. However, this flexibility may not be available in some deployments of other profiles (such as LE Audio), which may force a reconfiguration of the link to make any changes to the packet size or the interval between packets. This reconfiguration of the link may result in an interruption of the audio stream, which may adversely affect the user experience. In addition, the strict timing constraints associated with LE Audio may not allow the audio stream to be adjusted in response to changes in the wireless environment.

[0058] This change in wireless environment may be caused by the removal of wires between device 110 (e.g., phone) and headset. For example, while the user may no longer be tethered to the user's phone with a wire (and may instead be free to walk away from the phone), the user may still expect the same level of quality and latency. In other words, the user may expect a seamless audio experience from high-quality audio that is synchronized with the video (e.g., lip sync), and be able to place the phone in their back pocket or bag without glitches.

[0059] In some (e.g., manufacturer-specific or product-specific) extensions of the BLE standard, some devices may support the ability to adapt the link rate to changes in the environment. Such link rate adaptation can handle a range of use cases, such as when the user is close to the phone and when the user is at a certain distance from the phone. In some examples, such a link rate may be referred to as or understood as or reflected by the MCS. In addition, the MCS may be associated with a data rate protocol, which may be manufacturer-specific or product-specific and may range, for example, from MCS2 to MCS6. However, in such examples, due to the locked link configuration associated with BLE audio and the built-in robustness set that assumes (e.g., is able to handle) the worst-case scenario (e.g., which may refer to a scenario in which a user attempts to use an upper data rate or bandwidth amount for an audio data stream), the range of MCS2 to MCS6 may not be sufficient for streaming at a bandwidth provided or supported by some (e.g., manufacturer- or product-specific) data rate protocols.

[0060] In some implementations, one or both of the wireless device 205 and the wireless device 210 can employ techniques that allow a link (e.g., the communication link 215) to be dynamically configured without reestablishing the link. In addition, according to the described techniques, the wireless device 205 and the wireless device 210 can dynamically configure aspects of the communication link 215 (e.g., the BLE wireless link) without affecting the timing of the established CIS and without causing audio interruption. Thus, the wireless device 205 and the wireless device 210 can trade bandwidth robustness with each other (e.g., the number of retransmissions and bandwidth can be balanced).

[0061] For example, although the MCS rate can allow audio quality to be matched to the wireless environment, a single MCS rate may not solve the basic problem associated with BLE, and in some deployments, the retry ratio cannot be dynamically adjusted (e.g., without removing and rebuilding the link). In contrast, in some cases, all MCS rates can be locked to the same configuration (e.g., the same fixed BLE link configuration). In some aspects, the use case associated with the technology described herein can be used to exchange audio quality for robustness in a bit rate range from 100 kilobits per second (KBps) to 750KBps. In addition, the MCS2 to MCS6 rates can be limited to a ratio of 1:3. Therefore, in some implementations, the wireless device 205 or the wireless device 210 or both can link the change in the number of retransmission opportunities to the modulation scheme (e.g., MCS). In this way, if the rate adaptation algorithm drops from MCS6 to MCS2 as the communication link 215 deteriorates, the link configuration can be adjusted so that the number of transmission opportunities that can be used for retransmission increases (synchronized with the reduction in the bit rate of the codec).

[0062] In addition, wireless device 205 or wireless device 210 or both can configure a change in the number of retransmissions without changing the timing of the CIS (which can achieve compatibility with the Bluetooth standard and also avoid disruption to other devices, since changing the timing of the ISO interval or the CIS is associated with renegotiation not only at the transmitter and receiver, but also with other devices using the BLE link, where all such renegotiations may have relatively high robustness standards in degraded wireless environments). By linking the BN (which is inversely proportional to the number of retries available in a given ISO interval) or the FT or both to the modulation, wireless device 205 and wireless device 210 can avoid tuning a set of values ​​or settings for the CIS for performance in a worst-case environment, and can instead support multiple different sets of values ​​for the CIS, each set tuned for a variety of different environments.

[0063] For example, the modulation may reflect the wireless environment (e.g., how "good" or "bad" the wireless environment is, which may vary over time), and the wireless device 205 or the wireless device 210 may rely on the MCS and changes in the MCS to inform the BN or FT or both how to vary across ISO intervals within the CIS. For example, MCS6 may be used when the communication link 215 has relatively low errors, and if the communication link 215 deteriorates, MCS6 may be dropped to MCS2. Thus, the number of retries available in a given ISO interval (which may be controlled via the BN or FT or both) may be adjusted for a set of points within this range that reflect link performance, such as Figure 2 shown.

[0064] For example, for each MCS (from MCS2 to MCS6), the number of transmission opportunities available for retransmissions may be tuned to provide or achieve a tradeoff between coded audio bandwidth and bandwidth for additional retries. Figure 2 An example bandwidth that can be achieved for a given BN for each MCS is shown. Figure 2 As shown, lines 220 and 225 mark the bandwidth of BN=2 and BN=4, respectively, as the MCS changes, and line 230 shows how changing the BN can give a larger maximum bandwidth compared to going to the worst case scenario (e.g., reducing to MCS2, or tearing down and rebuilding a link with a lower BN, such as from BN=4 to BN=2). For example, instead of dropping from MCS6 to MCS2, the wireless device 205 or the wireless device 210 can drop from BN=4 to, for example, BN=3 and achieve a larger bandwidth (e.g., at least for MCS5 and MCS4).

[0065] In other words, the signaling diagram 200 shows the audio stream bit rate for each modulation. In addition, in order to change the number of transmission opportunities available for retransmission, the wireless device 205 or the wireless device 210 can change the BN, FT, or packet size. In this way, the wireless device 205 or the wireless device 210 can tune the BN, FT, packet size, or any combination thereof to give or set the tradeoff between the encoded audio bandwidth and the bandwidth for additional retries.

[0066] Changing the BN may provide more transmission opportunities and may result in the ability of the communication link 215 to handle a higher rate of packet errors. For example, the greater the number of opportunities available for retransmission, the greater the packet error rate (PER) that the communication link 215 can withstand. As an example, if the goal is a maximum of one lost packet per hour, the maximum PER may be calculated for a given retry budget, as shown in Table 1, where the maximum PER for each MCS is calculated based on the BN. In addition, Table 1 shows an example of BN values ​​and retry budgets (e.g., used in a working system) and the resulting maximum PER. In addition, a reference sensitivity may be calculated based on 30.8% PER / ≈1E-3 BER.

[0067]

[0068] Table 1: BN values ​​and retry budgets, and the resulting maximum PER

[0069] In addition, for robustness, the wireless device 205 and the wireless device 210 may support techniques that enable the communication link 215 to handle situations where several ISO intervals of protocol data units (PDUs) are missed or lost. For example, if a receiving device (e.g., a sink) is out of range of a transmitting device (e.g., a source), even briefly, and completely misses one or more isochronous events or intervals, there may be a relatively high probability that the number of PDUs flushed by the receiving device does not match the number of PDUs sent (and flushed) by the transmitting device. If such a mismatch occurs, the payload counter used for encryption between the wireless device 205 and the wireless device 210 may be off and may be unrecoverable. For example, if the BN difference between the transmitting device and the receiving device is assumed or expected to be only one, then after the FT+1 ISO interval, the payload counters between the transmitting device and the receiving device may differ by 2. If the payload counters at the transmitting device and the receiving device are different, the recovery options (e.g., a single recovery option) for the transmitting device and the receiving device may be to terminate and reestablish the CIS.

[0070] Thus, in some implementations, the wireless device 205 and the wireless device 210 may always force a rollover of the number BN_MAX of payload counters used for encryption at the end of a CIS event (e.g., at the end of each ISO interval). Thus, the wireless device 205 and the wireless device 210 may have synchronized payload counters at the beginning of each service data unit (SDU). For example, the wireless device 205 and the wireless device 210 may both increment the PDU sequence number by a fixed value after each ISO interval, regardless of the actual BN used for the ISO interval. Thus, even if the two ISO intervals are associated with different BNs according to the implementations described herein, the wireless device 205 and the wireless device 210 may increment the PDU sequence number by the same fixed value after each of the two different ISO intervals. In other words, the wireless device 205 and the wireless device 210 may support techniques associated with encryption to improve robustness to one or more lost packets.

[0071] Figure 3 An example of a communication timeline 300 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The communication timeline can implement or be implemented to implement or facilitate aspects of the wireless communication system 100 or the signaling diagram 200. For example, the communication timeline 300 shows communications between an initiator (e.g., a transmitting device or source device) and a recipient (e.g., a receiving device or sink device), which can be as follows: Figure 1 and Figure 2 Shown and referenced Figure 1 and Figure 2In some embodiments, the initiator and recipient may establish a CIS 305 associated with a set of ISO intervals 310 (which may refer to any one or more of ISO interval 310-a, ISO interval 310-b, and ISO interval 310-c), and may dynamically update or change how many transmission opportunities are available for retransmission on the ISO intervals 310 within the CIS 305.

[0072] In the example of the communication timeline 300, the ISO interval 310-a may include 4 transmission opportunities 315 for the initiator, including transmission opportunity 315-a, transmission opportunity 315-b, transmission opportunity 315-c, and transmission opportunity 315-d. The transmission opportunities 315 may be associated with sub-events, such that the ISO interval 310-a (and the CIS event associated with the ISO interval 310-a) may include 4 sub-events (e.g., number of sub-events (NSE) = 4). In some aspects, for the ISO interval 310-a, the initiator and the recipient may support a BN value of 2 and a FT value of 1. Therefore, the initiator may provide 2 payloads (e.g., PDUs) for transmission in the CIS event associated with the ISO interval 310-a. As shown in the communication timeline 300, the initiator may provide PDU_0 and PDU_1 for transmission in the CIS event associated with the ISO interval 310-a.

[0073] In some examples, the recipient may successfully receive PDU_0 in an initial transmission of PDU_0, and may send an acknowledgment (ACK) 320 to the initiator in response to PDU_0. The transmission opportunity 315-a and the ACK 320 may be within the same sub-event. Thus, the initiator may continue to send PDU_1, which the initiator may initially send during the transmission opportunity 315-b. If the initiator fails to receive an ACK for PDU_1 (or receives a negative ACK (NACK)), the initiator may perform one or more retransmissions of PDU_1. For example, the initiator may retransmit PDU_1 during each of the transmission opportunities 315-c and 315-d (e.g., in the absence of any ACK for PDU_1). As a result of the CIS event associated with the ISO interval 310-a including 4 sub-events and the FT being equal to 1, the initiator and the recipient may refresh PDU_1. In other words, the initiator may discard PDU_1 (and avoid further (re)transmission of PDU_1) after the ISO interval 310-a. Likewise, the recipient may avoid monitoring PDU_1 after ISO interval 310 - a .

[0074] In some embodiments, one or both of the initiator and the recipient may detect or measure a change in the quality of the link between the initiator and the recipient, and may update one or more parameters associated with the CIS 305 to adjust the number of transmission opportunities available for retransmissions accordingly. For example, the initiator or the recipient may detect or measure a deterioration in the quality of the link during the ISO interval 310-a (e.g., an increase in interference, a decrease in received signal quality or strength, or a decrease in the MCS used to communicate using the link may be measured), and in some embodiments, may dynamically update one or more parameters of the CIS 305 for the ISO interval 310-b to increase the number of transmission opportunities available for retransmissions.

[0075] In the example of the communication timeline 300, for example, the initiator and the recipient may update the BN and FT of the CIS 305 such that for the ISO interval 310-b, the BN is equal to 1 and the FT is equal to 2. Thus, the initiator may perform an initial transmission of PDU_2 during the transmission opportunity 325-a (e.g., as a result of refreshing PDU_1). If the initiator fails to receive an ACK for PDU_2 (or receives a NACK), the initiator may retransmit PDU_2 during one or more other transmission opportunities 325 of the ISO interval 310-b. As shown in the communication timeline 300, the initiator may retransmit PDU_2 during each of the transmission opportunity 325-b, the transmission opportunity 325-c, and the transmission opportunity 325-d without receiving an ACK for PDU_2. In some examples, the recipient may successfully receive PDU_2 during the transmission opportunity 325-d and may send an ACK 330 for PDU_2. The transmission opportunity 325-d and the ACK 330 may be within the same sub-event.

[0076] In some implementations, the initiator or recipient may detect or measure a change in the quality of the link between the initiator and the recipient, and may update one or more parameters associated with the CIS 305 to adjust the number of transmission opportunities available for retransmissions accordingly. For example, the initiator or recipient may detect or measure an improvement in the quality of the link during the ISO interval 310-b (e.g., a reduction in interference, an increase in received signal quality or strength, or an increase in the MCS used to communicate using the link may be measured), and in some implementations, may dynamically update one or more parameters of the CIS 305 for the ISO interval 310-c to reduce the number of transmission opportunities available for retransmissions.

[0077] In the example of communication timeline 300, for example, the initiator and the recipient may update the BN and FT of CIS 305 so that for ISO interval 310-c, BN is equal to 2 and FT is equal to 2. Therefore, the initiator may perform an initial transmission of PDU_3 during transmission opportunity 335-a (e.g., as a result of receiving ACK 330 for PDU_2). If the recipient successfully receives PDU_3 during transmission opportunity 335-a, the recipient may send ACK 340. Transmission opportunity 335-a and ACK 340 may be within the same sub-event. Based on receiving ACK 340 for PDU_3, the initiator may send PDU_4 during transmission opportunity 335-b. If the initiator fails to receive ACK for PDU_4 (or receives NACK), the initiator may perform one or more retransmissions of PDU_4. For example, the initiator may retransmit PDU_4 during each of transmission opportunity 335-c and transmission opportunity 335-d. In some examples, the recipient may successfully receive PDU_4 during transmission opportunity 335-d and may send ACK 345 for PDU_4. Transmission opportunity 335-d and ACK 345 may be within the same sub-event.

[0078] Furthermore, although illustrated and described in the context of dynamically changing how many transmission opportunities are available for retransmissions by adjusting or updating one or both of the BN or FT of the CIS 305 over the ISO interval 310, the initiator and recipient may additionally or alternatively adjust or update the packet size of the PDUs transmitted in each ISO interval 310, the NSE in each CIS event or ISO interval 310, or the number of subintervals in each CIS event or ISO interval 310 (where the subintervals may correspond to sub-events).

[0079] In addition, as described herein, the initiator and recipient can dynamically change how many transmission opportunities are available for retransmissions on the ISO interval 310 within the CIS 305 based on a mapping between the number of transmission opportunities that can be used for retransmissions (or one or more parameters that affect the number of transmission opportunities that can be used for retransmissions) and the MCS used by the initiator and recipient. The mapping can be signaled between the initiator and recipient, configured at each of the initiator and recipient, or any combination thereof. In some aspects, the initiator and recipient can use a first mapping for communications from a central device to a peripheral device and a second mapping for communications from a peripheral device to a central device, as described in reference to Figure 4 Described in more detail.

[0080] Figure 4An example of a signaling diagram 400 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The signaling diagram 400 can implement or be implemented to implement or facilitate aspects of the wireless communication system 100, the signaling diagram 200, or the communication timeline 300. For example, the signaling diagram 400 shows communications between a source device 405 and a sink device 410, which can be as described by Figure 1-Figure 3 Shown and referenced Figure 1-Figure 3 For example, source device 405 may be an example of wireless device 205 or wireless device 210 or an initiator, such as Figure 2 and Figure 3 Shown and referenced Figure 2 and Figure 3 In addition, the sink device 410 can be an example of the wireless device 205 or the wireless device 210 or the recipient, as shown by Figure 2 and Figure 3 Shown and referenced Figure 2 and Figure 3 as described.

[0081] In some implementations, the source device 405 and the sink device 410 may support signaling associated with dynamic CIS configuration updates to increase or decrease the number of transmission opportunities that can be used for retransmissions. For example, the source device 405 and the sink device 410 may negotiate, indicate, or agree on a set of CIS settings (e.g., including changes to the BN or the number of retries) for each MCS (e.g., each MCS rate). The source device 405 and the sink device 410 may use a mapping indication message 435 to perform such negotiation, indication, or agreement. The mapping indication message 435 may include a table of values ​​of the BN to be used for each MCS, timing information including the time to apply the value of the BN that allows dynamic updates, or the maximum length of the PDU for each MCS (because changes in the BN may also affect the maximum length of the PDU), or any combination thereof.

[0082] In other words, the mapping indication message 435 may indicate a mapping between how many transmission opportunities are available for retransmissions (e.g., via a BN value and a PDU packet length) for each MCS. In addition, in some implementations, the mapping indication message 435 may indicate two separate mappings, including a first mapping for communication from a central device to a peripheral device and a second mapping for communication from a peripheral device to a central device. Thus, the source device 405 and the sink device 410 may use the mapping indication message 435 to establish and update the CIS. An exemplary structure, format, and content of the mapping indication message 435 (e.g., a control data field of the mapping indication message 435) is shown by Table 1 shown below.

[0083]

[0084] Table 1: Contents of the mapping indication message

[0085] As shown in Table 1, "Max_PDU_C_To_P_MCS6" may indicate the maximum PDU length for communication from a central device to a peripheral device for MCS6, "Max_PDU_P_To_C_MCS6" may indicate the maximum PDU length for communication from a peripheral device to a central device for MCS6, "BN_C_To_P_MCS6" may indicate the BN for communication from a central device to a peripheral device for MCS6, and "BN_P_To_C_MCS6" may indicate the BN for communication from a peripheral device to a central device for MCS6. The mapping indication message 435 may similarly indicate the maximum PDU length and BN value for central device to peripheral device communication and for peripheral device to central device communication for each MCS value from MCS6 to MCS2. Therefore, the source device 405 and the sink device 410 may update the BN value synchronously (in the same manner) as the MCS changes.

[0086] As an extension of the signaling of the mapping indication message 435, the source device 405 and the sink device 410 can support dynamic use of the microphone back channel. For example, when a user is playing a game, other players can join or leave. The user can open a voice back channel or receive a call while listening to the audio from the game. In addition, at the implementation level, there may be multiple ways in which the phone can access the microphone on a set of headphones. For example, each headset can have a microphone, and the switch microphone can be used to select the microphone with the best signal. At other times, the phone can use two microphones to allow the use of more complex down-mixing and signal extraction techniques. Such dynamic behavior may not be possible in some deployments because, on the contrary, when the CIS is created, the bandwidth for the microphone back channel can be allocated (even if it is not used from the beginning of the CIS, because the BLE protocol may not allow the bandwidth for the return channel to be adjusted dynamically).

[0087] BLE may define a subinterval SUB_INTERVAL to have 2 PDUs (e.g., one packet in both directions), where each PDU is used to acknowledge a PDU in the opposite direction. Thus, a PDU without a payload may be an ACK. In some cases, the MAX_PDU_C_TO_P and MAX_PDU_P_TO_C fields of the CIS request message may give the maximum size of a PDU in each direction, where a zero size may indicate that no data is carried in that corresponding direction.

[0088] Therefore, in some embodiments, the source device 405 can use the mapping indication message 435 to dynamically enable or disable the communication link from the peripheral device to the central device (e.g., the microphone backchannel) by setting the corresponding fields of the mapping indication message 435 to zero length or non-zero length, respectively. For example, if the mapping entry associated with the second mapping (for communication from the peripheral device to the central device) has a zero length, the backchannel link from the peripheral device to the central device can be disabled. Alternatively, if the mapping entry associated with the second mapping has a non-zero length, the backchannel link from the peripheral device to the central device can be enabled. Therefore, the sending or receiving of the mapping indication message 435 can dynamically enable or disable the backchannel link.

[0089] In other words, the mapping indication message 435 can indicate a dynamic adjustment of the bandwidth allocated for the reverse channel, which can include a zero length when the link is (e.g., temporarily) disabled. For link robustness, this can allow bandwidth to be exchanged between the uplink and the downlink. For example, a voice link may be easier to hide lost packets for packet loss concealment (PLC), while a link with complex audio may be more difficult to hide lost packets for PLC. Therefore, given two links in the example, the bandwidth of the complex audio link can be protected on the voice reverse channel.

[0090] The source device 405 may include one or more components for implementing the techniques described herein. For example, the source device 405 may include an adaptive service layer (ALS) 415, an encoder 420, and a Bluetooth source component 425. The source device 405 may also include a BN mapping component 430, which the source device 405 may use to initialize and update the BN value table indicated via the mapping indication message 435. The sink device 410 may include one or more components for implementing the techniques described herein. For example, the sink device 410 may include a decoder 450, a Bluetooth sink component 455, a length hardening component 460, and a majority voting algorithm (MVA) component 465. The decoder 450 may provide robustness metadata 440 to the Bluetooth sink component 455. In addition, the Bluetooth sink component 455 may provide PDU length information 445 (e.g., as obtained from the mapping indication message 435) to the length hardening component 460.

[0091] For example, as another extension of the signaling of the mapping indication message 435, the sink device 410 may provide the mapping indication message 435 to the length hardening component 460, which may increase the ability of the sink device 410 to correct potentially erroneously received PDUs. For example, although the payload and modulation of the packet may be protected by forward error correction (FEC) and MVA, the length field is still a relative weakness of the PDU (e.g., a damaged header that may indicate the length of the PDU may be a significant cause of lost packets). In addition, in 10 -3 At a bit error rate of 100,000, a 10-bit length field as used by some extensions may have 1 / 100 PDU with a length error, which may correspond to approximately 3 PDUs per second (e.g., expecting 3 retries and 10 ms audio frames).

[0092] The length can have a significant impact on the ability of the MVA (e.g., MVA component 465) to repair the packet. For example, if a packet is incorrectly shortened, there may not be enough data to apply a majority vote (e.g., MVA). In addition, the LE audio standard may specify 3 receive opportunities in some configurations, which may result in no combining. In low-latency streaming or broadcasting, this may be equivalent to 3 PDU packets per second, for which majority voting cannot be applied. For the calculation of the cyclic redundancy check (CRC), length hardening bits can be used instead of the actual received bits. Therefore, the length hardening technique using the mapping indication message 435 can allow dynamic changes in the bit rate while also mitigating the weaknesses of the length field. This technique can be used with any LE audio stream because the relevant standard defines a fixed size Low Complexity Communications Codec (LC3) audio frame.

[0093] For example, sink device 410 may receive mapping indication message 435 and indicate the size of the PDU to length hardening component 460 (e.g., a length hardening function), and thus, sink device 410 may read an amount of data at each transmission opportunity of the ISO interval that is equal to the size of the PDU indicated to length hardening component 460. Thus, each PDU received by sink device 410 has the same size (e.g., because the size indicated to length hardening component 460 may override the size indicated by the length field of the header of the PDU).

[0094] In some aspects, if the length field is enabled and when processing the header, an override of the length field can occur (e.g., when receiving a packet, the modem can use the size indicated to the length hardening component 460, otherwise the modem can read the header and use the length field to configure how much data to read from the channel, which may also affect parity. In other words, the modem of the sink device 410 can be forced to read a fixed amount of data from the physical channel according to the size indicated to the length hardening component 460, and the fixed amount of data can be defined for each MCS. Therefore, length hardening can be an extension of the signaling of the mapping indication message 435 to improve robustness to bit errors in the length field.

[0095] Therefore, if the sink device 410 fails to decode a single PDU or the same PDU multiple times (e.g., two or more times), the sink device 410 can use a majority voting algorithm to handle the multiple failed attempts to decode the PDU, wherein if the majority voting algorithm detects a difference in the length field of the multiple failed decoding attempts, the majority voting algorithm uses the size indicated to the length hardening component 460 to correct the PDU (e.g., if the error is at the length field of the PDU, because the majority voting algorithm can be an algorithm that locates the error by checking the difference between multiple decoding attempts of the same PDU, and attempts to repair the error in the PDU by selecting the most common state at the location of each error in the multiple attempts or by using redundant coding).

[0096] Figure 5 An example of a process flow 500 supporting techniques for dynamically adjusting retransmission opportunities within a CIS in accordance with one or more aspects of the present disclosure is shown. The process flow 500 can implement or be implemented to implement or facilitate aspects of the wireless communication system 100, the signaling diagram 200, the communication timeline 300, or the signaling diagram 400. For example, the process flow 500 shows communications between a host 505 (e.g., host A), an initiation layer 510 (which can be equivalently referred to as an initiation link layer), a response layer 515 (which can be equivalently referred to as a response link layer), a host 520 (e.g., host B), and a length hardening component 525 (which can be equivalently referred to as a length hardening sink or a length hardening function).

[0097] In the following description of process flow 500, operations (such as reporting or providing) may be performed in a different order than shown, or operations performed by the example device may be performed in a different order or at a different time. For example, certain operations may also be omitted from process flow 500, or other operations may be added to process flow 500. In addition, although some operations or signaling may be shown as occurring at different times for discussion purposes, these operations may actually occur simultaneously.

[0098] At 530, the host 505 and the initiator layer 510 can create a connected isochronous group (CIG), which can be referred to as or associated with step 1. The CIG can include one or more CISs. In some aspects, step 1 can encompass the operations of 532 and 534.

[0099] At 532, as part of step 1, the host 505 can send a CIG configuration message to the initiation layer 510. In some aspects, the CIG configuration message can be a host controller interface (HCI) LE_Set_CIG_Parameters command. The CIG configuration message can set or configure one or more parameters that may affect audio quality and latency.

[0100] At 534, also as part of step 1, the initiator layer 510 can send a command completion message to the host 505. In some aspects, the command completion message can be an HCI command completion message.

[0101] At 536, the host 505 and the initiating layer 510 may provide values ​​for a set (if not all) of the MCS rates, which may be referred to as or associated with step 2. For example, the host 505 and the initiating layer 510 may provide (Max_PDU, BN) values ​​for all MCS rates. In some aspects, step 2 may encompass the operations of 538 and 540.

[0102] At 538, as part of step 2, the host 505 may send a BN map message to the initiation layer 510. In some aspects, the BN map message may be an HCI_Set_CIG_MCS_Map message, which may be a product-specific or manufacturer-specific message or otherwise convey product-specific or manufacturer-specific parameters.

[0103] At 540, also as part of step 2, the initiating layer 510 can send a command completion message. In some aspects, the command completion message can be an HCI command completion message.

[0104] At 542, host 505, initiation layer 510, response layer 515, and host 520 may create a first CIS in the CIG, which may be referred to as or associated with step 3. In some aspects, step 3 may encompass operations of 544 to 562.

[0105] At 544, the host 505 may send a Create CIS message to the initiator layer 510. In some aspects, the Create CIS message may be an HCI_LE_Create_CIS message.

[0106] At 546, the initiation layer 510 may send a command status message to the host 505. In some aspects, the command status message may be an HCI command status message.

[0107] At 548, the initiating layer 510 may send a link layer CIS_REQ message to the responding layer 515. In some aspects, the CIS request message may be a product-specific or manufacturer-specific link layer CIS request message.

[0108] At 550, the response layer 515 may send a CIS request message to the host 520. In some aspects, the CIS request message may be an HCI LE CIS Request message.

[0109] At 552, the host 520 may send an Accept CIS request message to the response layer 515. The Accept CIS request message may be an HCI LE Accept CIS request message.

[0110] At 554, the response layer 515 may send a command status message to the host 520. In some aspects, the command status message may be an HCI command status message.

[0111] At 556, the response layer 515 may send a CIS response message to the initiation layer 510. In some aspects, the CIS response message may be a link layer CIS_RSP message.

[0112] At 558, the initiating layer 510 may send a CIS indication message to the responding layer 515. In some aspects, the CIS indication message may be a link layer CIS_IND message.

[0113] At 560, the host 505 may send a CIS Established indication to the host 505. In some aspects, the CIS Established indication may be an HCI LE CIS Established message.

[0114] At 562, the response layer 515 may send a CIS Established indication to the host 520. In some aspects, the CIS Established indication may be an HCI LE CIS Established message.

[0115] Figure 6 An example of a process flow 600 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The process flow 600 may implement or be implemented to implement or facilitate aspects of the wireless communication system 100, signaling diagram 200, communication timeline 300, or signaling diagram 400.

[0116] In some aspects, process flow 600 may be a continuation or extension of process flow 500 (e.g., the operation of 605 may be immediately followed by the operation of 562). For example, process flow 500 may illustrate steps 1, 2, and 3, and process flow 600 may illustrate steps 4 and 5. Similarly, process flow 600 illustrates communications between a host 505 (e.g., host A), an initiation layer 510 (which may equivalently be referred to as an initiation link layer), a response layer 515 (which may equivalently be referred to as a response link layer), a host 520 (e.g., host B), and a length hardening component 525 (which may equivalently be referred to as a length hardening sink or a length hardening function). Process flow 500 and process flow 600 may together illustrate an extended CIS BN update process (e.g., establishing and / or updating a CIS via a mapping indication message such as mapping indication message 435).

[0117] In the following description of process flow 600, operations (such as reporting or providing) may be performed in a different order than shown, or operations performed by the example device may be performed in a different order or at a different time. For example, certain operations may also be omitted from process flow 600, or other operations may be added to process flow 600. Furthermore, although some operations or signaling may be shown as occurring at different times for discussion purposes, these operations may actually occur simultaneously.

[0118] At 605, the initiating layer 510 and the responding layer 515 may provide values ​​for a set (if not all) of MCS rates, which may be referred to as or associated with step 4. For example, the initiating layer 510 and the responding layer 515 may provide, negotiate, or indicate (Max_PDU, BN) values ​​for all MCS rates. In some aspects, step 4 may encompass the operations of 610 to 635.

[0119] At 610, the initiating layer 510 may send a mapping indication message to the responding layer 515. In some aspects, the mapping indication message may be a product-specific or manufacturer-specific mapping indication message. The mapping indication message may be such as Figure 4 Show and refer to Figure 4An example of a mapping indication message 435 described. In some implementations, a table indicating the correspondence between BN values ​​and MCS rates can be sent or indicated via the mapping indication message 435, and the table can be updated and synchronized by the ISO_Interval event count on both sides (e.g., at both the host 505 and the host 520). In this way, the host 505 and the host 520 can maintain the same understanding of the BN-MCS mapping table to be used by tracking and incrementing the ISO_Interval event count and synchronizing changes in the BN-MCS mapping table to the ISO_Interval event count. For example, the host 505 and the host 520 can update the table every X ISO_Interval events, where X can be static or changing and can be any integer including 1, 2, 3, 4, etc.

[0120] At 615 , the response layer 515 may send information for length hardening to the length hardening component 525 (eg, via the host 520 ).

[0121] At 620, the length hardening component 525 can configure length hardening using information from the table indicated by the mapping indication message, as shown in FIG. Figure 4 Described in more detail.

[0122] At 625, the response layer 515 may send an ACK in response to the mapping indication message to the initiation layer 510. In some aspects, the ACK may be a link layer ACK.

[0123] At 630 , the host 505 may send one or more SDUs corresponding to the first MCS to the initiating layer 510 .

[0124] At 635 , the initiating layer 510 and the responding layer 515 may exchange one or more CIS PDUs corresponding to the one or more SDUs provided at 630 using the first MCS.

[0125] At 640, the initiating layer 510 and the responding layer 515 may switch to a different SDU size, which may be referred to as or associated with step 5. In some aspects, step 5 may encompass the operations of 645 and 650.

[0126] At 645 , the host 505 may send one or more SDUs corresponding to the second MCS to the initiating layer 510 .

[0127] At 650, the initiating layer 510 and the response layer 515 may exchange one or more CIS PDUs corresponding to the one or more SDUs provided at 645 using the second MCS. In some implementations, the initiating layer 510 and the response layer 515 may dynamically update one or more parameters that affect how many transmission opportunities are available for retransmissions based on switching from the first MCS to the second MCS. For example, the initiating layer 510 and the response layer 515 may increase the number of transmission opportunities that may be used for retransmissions as the MCS decreases (e.g., as link quality deteriorates), and may decrease the number of transmission opportunities that may be used for retransmissions as the MCS increases (e.g., as link quality improves).

[0128] Figure 7 A block diagram 700 of a device 705 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The device 705 may be an example of aspects of a Bluetooth device as described herein. The device 705 may include a receiver 710, a transmitter 715, and an I / O controller 720. The device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0129] The receiver 710 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques for dynamically adjusting retransmission opportunities within the CIS). The information may be communicated to other components of the device 705. The receiver 710 may utilize a single antenna or a collection of multiple antennas.

[0130] The transmitter 715 may provide means for transmitting signals generated by other components of the device 705. For example, the transmitter 715 may transmit information associated with various information channels (e.g., control channels, data channels, information channels related to techniques for dynamically adjusting retransmission opportunities within the CIS), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 715 may be co-located with the receiver 710 in a transceiver module. The transmitter 715 may utilize a single antenna or a collection of multiple antennas.

[0131] The I / O controller 720, the receiver 710, the transmitter 715, or various combinations thereof, or various components thereof, may be examples of components for performing various aspects of the techniques for dynamically adjusting retransmission opportunities within a CIS as described herein. For example, the I / O controller 720, the receiver 710, the transmitter 715, or various combinations or components thereof, may support methods for performing one or more functions described herein.

[0132] In some examples, I / O controller 720, receiver 710, transmitter 715, or various combinations or components thereof can be implemented in hardware (e.g., in a communications management circuit). The hardware may include a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof, configured to or otherwise support components for performing the functions described in the present disclosure. In some examples, a processor and a memory coupled to the processor can be configured to perform one or more functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0133] Additionally or alternatively, in some examples, I / O controller 720, receiver 710, transmitter 715, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communications management software or firmware). If implemented in code executed by a processor, the functions of I / O controller 720, receiver 710, transmitter 715, or various combinations or components thereof may be performed by a general purpose processor, DSP, CPU, ASIC, FPGA, microcontroller, or any combination of these or other programmable logic devices (e.g., configured or otherwise supported to perform the functions described in the present disclosure).

[0134] In some examples, I / O controller 720 may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with receiver 710, transmitter 715, or both. For example, I / O controller 720 may receive information from receiver 710, send information to transmitter 715, or be integrated with receiver 710, transmitter 715, or both in combination to obtain information, output information, or perform various other operations as described herein.

[0135] The I / O controller 720 may support wireless communication at a first wireless device according to the examples disclosed herein. For example, the I / O controller 720 may be configured to or otherwise support a component for sending or receiving a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmission via the CIS and a corresponding MCS of the CIS. The I / O controller 720 may be configured to or otherwise support a component for detecting a change in the MCS of the CIS during a first ISO interval of the CIS. The I / O controller 720 may be configured to or otherwise support a component for the following operations: for a second ISO interval of the CI, adjusting the number of transmission opportunities allocated for retransmission according to the detected change in the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration. The I / O controller 720 may be configured to or otherwise support a component for sending or receiving one or more audio data packets using a second wireless device during the second ISO interval according to the adjusted number of transmission opportunities allocated for retransmission.

[0136] By including or configuring an I / O controller 720 according to the examples described herein, a device 705 (e.g., a control processor 710, a transmitter 715, an I / O controller 720, or a combination thereof or a receiver otherwise coupled to a receiver 710, a transmitter 715, an I / O controller 720, or a combination thereof) can support techniques for reduced processing, reduced power consumption, and more efficient use of communication resources.

[0137] Figure 8 A block diagram 800 of a device 805 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The device 805 may be an example of aspects of the device 705 or paired device 115 as described herein. The device 805 may include a receiver 810, a transmitter 815, and an I / O controller 820. The device 805 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0138] The receiver 810 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels, data channels, information channels related to techniques for dynamically adjusting retransmission opportunities within the CIS). The information may be communicated to other components of the device 805. The receiver 810 may utilize a single antenna or a collection of multiple antennas.

[0139] The transmitter 815 may provide means for transmitting signals generated by other components of the device 805. For example, the transmitter 815 may transmit information associated with various information channels (e.g., control channels, data channels, information channels related to techniques for dynamically adjusting retransmission opportunities within the CIS), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 815 may be co-located with the receiver 810 in a transceiver module. The transmitter 815 may utilize a single antenna or a collection of multiple antennas.

[0140] Device 805 or its various components can be examples of parts for performing various aspects of the technology for dynamically adjusting the retransmission opportunities in CIS as described herein. For example, I / O controller 820 may include mapping component 825, link quality component 830, CIS adjustment component 835, audio data component 840 or any combination thereof. I / O controller 820 can be an example of various aspects of I / O controller 720 as described herein. In some examples, I / O controller 820 or its various components can be configured to use or otherwise cooperate with receiver 810, transmitter 815 or both to perform various operations (e.g., receive, obtain, monitor, output, send). For example, I / O controller 820 can receive information from receiver 810, send information to transmitter 815, or integrate with receiver 810, transmitter 815 or both combinations to obtain information, output information or perform various other operations as described herein.

[0141] The I / O controller 820 may support wireless communications at a first wireless device according to examples disclosed herein. The mapping component 825 may be configured to or otherwise support a component for sending or receiving a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmission via the CIS and a corresponding MCS of the CIS. The link quality component 830 may be configured to or otherwise support a component for detecting a change to the MCS of the CIS during a first ISO interval of the CIS. The CIS adjustment component 835 may be configured to or otherwise support a component for the following operations: for a second ISO interval of the CIS, adjusting the number of transmission opportunities allocated for retransmissions based on the detected change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration. The audio data component 840 may be configured to or otherwise support a component for sending or receiving one or more audio data packets using a second wireless device during the second ISO interval based on the adjusted number of transmission opportunities allocated for retransmissions.

[0142] Fig. 9A block diagram 900 of an I / O controller 920 supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The I / O controller 920 may be an example of aspects of the I / O controller 720, the I / O controller 820, or both as described herein. The I / O controller 920 or its various components may be examples of components for performing various aspects of the techniques for dynamically adjusting retransmission opportunities within a CIS as described herein. For example, the I / O controller 920 may include a mapping component 925, a link quality component 930, a CIS adjustment component 935, an audio data component 940, a payload counter component 945, a length hardening component 950, a channel scoring component 955, a majority voting algorithm component 960, or any combination thereof. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

[0143] The I / O controller 920 may support wireless communication at a first wireless device according to the examples disclosed herein. The mapping component 925 may be configured to or otherwise support a component for sending or receiving a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmission via the CIS and a corresponding MCS of the CIS. The link quality component 930 may be configured to or otherwise support a component for detecting a change to the MCS of the CIS during a first ISO interval of the CIS. The CIS adjustment component 935 may be configured to or otherwise support a component for adjusting the number of transmission opportunities allocated for retransmission for a second ISO interval of the CIS according to the detected change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration. The audio data component 940 may be configured to or otherwise support a component for sending or receiving one or more audio data packets using a second wireless device during the second ISO interval according to the adjusted number of transmission opportunities allocated for retransmission.

[0144] In some examples, to support adjusting the number of transmission opportunities allocated for retransmissions, CIS adjustment component 935 can be configured or otherwise support components for increasing the number of transmission opportunities allocated for retransmissions as the MCS decreases from a relatively higher MCS to a relatively lower MCS. In some examples, to support adjusting the number of transmission opportunities allocated for retransmissions, CIS adjustment component 935 can be configured or otherwise support components for decreasing the number of transmission opportunities as the MCS increases from a relatively lower MCS to a relatively higher MCS.

[0145] In some examples, to support adjusting the number of transmission opportunities allocated for retransmissions, the CIS adjustment component 935 can be configured to or otherwise support components for reducing the BN associated with the CIS as the MCS decreases from a relatively higher MCS to a relatively lower MCS, wherein reducing the BN is associated with an increase in the number of transmission opportunities allocated for retransmissions. In some examples, to support adjusting the number of transmission opportunities allocated for retransmissions, the CIS adjustment component 935 can be configured to or otherwise support components for increasing the BN associated with the CIS as the MCS increases from a relatively lower MCS to a relatively higher MCS, wherein increasing the BN is associated with a decrease in the number of transmission opportunities allocated for retransmissions.

[0146] In some examples, to support adjusting the number of transmission opportunities allocated for retransmissions, CIS adjustment component 935 can be configured to or otherwise support components for increasing the FT associated with the CIS as the MCS decreases from a relatively higher MCS to a relatively lower MCS, wherein increasing the FT is associated with an increase in the number of transmission opportunities allocated for retransmissions. In some examples, to support adjusting the number of transmission opportunities allocated for retransmissions, CIS adjustment component 935 can be configured to or otherwise support components for decreasing the FT associated with the CIS as the MCS increases from a relatively lower MCS to a relatively higher MCS, wherein decreasing the FT is associated with a decrease in the number of transmission opportunities allocated for retransmissions.

[0147] In some examples, a BN associated with a CIS, a FT associated with a CI, and a packet size are tuned for each MCS in a set of multiple MCSs. In some examples, the BN, FT, and packet size are dynamically changed in response to a change to the MCS.

[0148] In some examples, the payload counter component 945 can be configured or otherwise support components for incrementing the PDU sequence number by a fixed value after a first ISO interval, wherein the first ISO interval is associated with a first BN. In some examples, the payload counter component 945 can be configured or otherwise support components for incrementing the PDU sequence number by a fixed value after a second ISO interval, wherein the second ISO interval is associated with a second BN different from the first BN.

[0149] In some examples, the first wireless device increments the PDU sequence number by a fixed value after each ISO interval, regardless of an actual BN associated with the ISO interval, in accordance with adjusting the number of transmission opportunities allocated for retransmissions across ISO intervals.

[0150] In some examples, the mapping indicates, for each MCS in a set of multiple MCSs, a corresponding number of transmission opportunities allocated for retransmission, timing information associated with an adjustment to the corresponding number of transmission opportunities allocated for retransmission, and a size of the PDU.

[0151] In some examples, the control message further indicates, for each MCS, the number of sub-events or the number of sub-intervals during the ISO interval.

[0152] In some examples, length hardening component 950 can be configured to or otherwise support components for indicating a size of a PDU for a length hardening function at the first wireless device. In some examples, channel scoring component 955 can be configured to or otherwise support components for: based on indicating a size of the PDU to the length hardening function, reading an amount of data equal to the size of the PDU at each transmission opportunity of the ISO interval such that each PDU received by the first wireless device has the same size, wherein the size of the PDU indicated to the length hardening function overrides a second size indicated by a header of the PDU.

[0153] In some examples, the majority voting algorithm component 960 can be configured as or otherwise support components for handling two or more failed attempts to decode a single PDU using a majority voting algorithm, wherein the majority voting algorithm is associated with a size indicated to a length hardening function, and wherein, if the majority voting algorithm detects a difference in length fields across two or more failed attempts to decode the single PDU, the majority voting algorithm corrects the PDU using the size indicated to the length hardening function.

[0154] In some examples, the control message indicates a mapping between a respective number of transmission opportunities allocated for retransmission and a respective MCS for each of two different communication directions. In some examples, the mapping includes a first mapping for communication from the central device to the peripheral device and a second mapping for communication from the peripheral device to the central device.

[0155] In some examples, when the reverse channel link from the peripheral device to the central device is disabled, the mapping entry associated with the second mapping has a zero length, and when the reverse channel link from the peripheral device to the central device is enabled, the mapping entry associated with the second mapping has a non-zero length. In some examples, the sending or receiving of the control message dynamically enables or disables the reverse channel link based on whether the mapping entry associated with the second mapping has a zero length or a non-zero length.

[0156] In some examples, to support sending or receiving one or more audio data packets during a second ISO interval, the audio data component 940 may be configured as or otherwise support components for sending one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets to a second wireless device based on a number of transmission opportunities allocated for retransmissions, wherein the first wireless device is configured as a sending device and the second wireless device is configured as a receiving device.

[0157] In some examples, to support sending or receiving one or more audio data packets during a second ISO interval, the audio data component 940 can be configured as or otherwise support components for receiving one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets from a second wireless device based on a number of transmission opportunities allocated for retransmissions, wherein the first wireless device is configured as a receiving device and the second wireless device is configured as a sending device.

[0158] Fig.10 A diagram of a system 1000 including a device 1005 that supports techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The device 1005 may be an example of or include components of a device 705, a device 805, or a Bluetooth device as described herein. The device 1005 may include components for two-way voice and data communications, including components for sending and receiving communications, such as an I / O controller 1020, an antenna 1010, a memory 1025, a processor 1030, a transceiver 1035, a coding manager 1040, and software 1045. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1015).

[0159] The memory 1025 may include random access memory (RAM) and read-only memory (ROM). The memory 1025 may store computer-readable, computer-executable software 1045 including instructions that, when executed by the processor 1030, cause the device 1005 to perform the various functions described herein. The software 1045 may be stored in a non-transitory computer-readable medium (such as system memory or other types of memory). In some cases, the software 1045 may not be directly executed by the processor 1030, but may cause the computer (e.g., when compiled and executed) to perform the functions described herein. In some cases, the memory 1025 may include a BIOS, etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0160] Processor 1030 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1030 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 1030. Processor 1030 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1025) to enable device 1005 to perform various functions (e.g., functions or tasks that support techniques for dynamically adjusting retransmission opportunities within a CIS). For example, device 1005 or a component of device 1005 may include processor 1030 and memory 1025 coupled to or coupled to processor 1030, and processor 1030 and memory 1025 are configured to perform various functions described herein.

[0161] In some cases, the device 1005 may include a single antenna 1010. However, in some other cases, the device 1005 may have more than one antenna 1010, which may be capable of concurrently sending or receiving multiple wireless transmissions. The transceiver 1035 may communicate bidirectionally via one or more antennas 1010, a wired or wireless link, as described herein. For example, the transceiver 1035 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1035 may also include a modem to modulate packets and provide the modulated packets to one or more antennas 1010 for transmission, and demodulate packets received from one or more antennas 1010. The transceiver 1035 or the transceiver 1035 and one or more antennas 1010 may be examples of transmitters 715, transmitters 815, receivers 710, receivers 810, or any combination thereof or components thereof as described herein.

[0162] The software 1045 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting techniques for dynamically adjusting retransmission opportunities within the CIS. The software 1045 may be stored in a non-transitory computer-readable medium such as a system memory or other type of memory. In some cases, the software 1045 may not be directly executed by the processor 1030, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0163] The I / O controller 1020 may support wireless communication at a first wireless device according to the examples disclosed herein. For example, the I / O controller 1020 may be configured to or otherwise support a component for sending or receiving a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmission via the CIS and a corresponding MCS of the CIS. The I / O controller 1020 may be configured to or otherwise support a component for detecting a change to the MCS of the CIS during a first ISO interval of the CIS. The I / O controller 1020 may be configured to or otherwise support a component for the following operations: for a second ISO interval of the CI, adjusting the number of transmission opportunities allocated for retransmission according to the detection of a change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration. The I / O controller 1020 may be configured to or otherwise support a component for sending or receiving one or more audio data packets using a second wireless device during the second ISO interval according to the adjusted number of transmission opportunities allocated for retransmission.

[0164] By including or configuring I / O controller 1020 according to examples as described herein, device 1005 can support techniques for improved communication reliability, reduced latency, an improved user experience associated with reduced processing, reduced power consumption, more efficient use of communication resources, improved coordination between devices, longer battery life, and improved utilization of processing power.

[0165] I / O controller 1020 can manage input and output signals for device 1005. I / O controller 1020 can also manage peripheral devices that are not integrated into device 1005. In some cases, I / O controller 1020 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1020 can utilize an operating system, such as or another known operating system. In other cases, I / O controller 1020 can represent a modem, keyboard, mouse, touch screen or similar device or interact with a modem, keyboard, mouse, touch screen or similar device. In some cases, I / O controller 1020 can be implemented as a part of a processor (such as processor 1030). In some cases, a user can interact with device 1005 via I / O controller 1020 or via a hardware component controlled by I / O controller 1020.

[0166] Fig.11 A flow chart illustrating a method 1100 for supporting techniques for dynamically adjusting retransmission opportunities within a CIS according to one or more aspects of the present disclosure is shown. The operations of the method 1100 may be implemented by a Bluetooth device or a component thereof as described herein. For example, the operations of the method 1100 may be implemented by a Bluetooth device or a component thereof as described herein. Figures 1 to 10 In some examples, the Bluetooth device may execute an instruction set to control functional elements of the Bluetooth device to perform the described functions. Additionally or alternatively, the Bluetooth device may use dedicated hardware to perform various aspects of the described functions.

[0167] At 1105, the method may include sending or receiving a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmission via the CIS and a corresponding MCS of the CIS. The operations of 1105 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1105 may be performed as described with reference to Fig. 9 The described mapping component 925 is performed.

[0168] At 1110, the method may include detecting a change to the MCS of the CIS during a first ISO interval of the CIS. The operations of 1110 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1110 may be performed as described with reference to Fig. 9 The link quality component 930 described above is performed.

[0169] At 1115, the method may include, for a second ISO interval of the CI, adjusting a number of transmission opportunities allocated for retransmissions based on detecting a change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration. The operations of 1115 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1115 may be performed as described with reference to Fig. 9 The described CIS adjustment component 935 is performed.

[0170] At 1120, the method may include transmitting or receiving one or more audio data packets using a second wireless device during a second ISO interval according to the adjusted number of transmission opportunities allocated for retransmission. The operations of 1120 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1120 may be performed as described with reference to Fig. 9 The described audio data component 940 is executed.

[0171] The following provides an overview of various aspects of the present disclosure:

[0172] Aspect 1: A method for wireless communication at a first wireless device, comprising: sending or receiving a control message indicating a mapping between a corresponding number of transmission opportunities allocated for retransmission via a CIS and a corresponding MCS of the CIS; detecting a change to the MCS of the CIS during a first ISO interval of the CIS; adjusting, for a second ISO interval of the CI, the number of transmission opportunities allocated for the retransmission based on the detected change to the MCS and the mapping, wherein the first ISO interval and the second ISO interval span the same duration; and sending or receiving one or more audio data packets using a second wireless device during the second ISO interval based on the adjusted number of transmission opportunities allocated for retransmission.

[0173] Aspect 2: A method according to Aspect 1, wherein adjusting the number of transmission opportunities allocated for retransmission includes: increasing the number of transmission opportunities allocated for retransmission as the MCS decreases from a relatively higher MCS to a relatively lower MCS; and reducing the number of transmission opportunities as the MCS increases from a relatively lower MCS to a relatively higher MCS.

[0174] Aspect 3: A method according to any one of Aspects 1 to 2, wherein adjusting the number of transmission opportunities allocated for retransmission includes: reducing the BN associated with the CIS as the MCS decreases from a relatively higher MCS to a relatively lower MCS, wherein the reduction in the BN is associated with an increase in the number of transmission opportunities allocated for retransmission; and increasing the BN associated with the CIS as the MCS increases from a relatively lower MCS to a relatively higher MCS, wherein the increase in the BN is associated with a decrease in the number of transmission opportunities allocated for retransmission.

[0175] Aspect 4: A method according to any one of Aspects 1 to 3, wherein adjusting the number of transmission opportunities allocated for retransmission includes: increasing the FT associated with the CIS as the MCS decreases from a relatively higher MCS to a relatively lower MCS, wherein the increase in the FT is associated with an increase in the number of transmission opportunities allocated for retransmission; and decreasing the FT associated with the CIS as the MCS increases from a relatively lower MCS to a relatively higher MCS, wherein the decrease in the FT is associated with a decrease in the number of transmission opportunities allocated for retransmission.

[0176] Aspect 5: A method according to any one of Aspects 1 to 4, wherein, for each MCS among multiple MCSs, a BN associated with the CI, an FT associated with the CI, and a packet size are tuned, and the BN, FT, and packet size are dynamically changed in response to a change in the MCS.

[0177] Aspect 6: The method according to any one of Aspects 1 to 5 further includes: incrementing the PDU sequence number by a fixed value after a first ISO interval, wherein the first ISO interval is associated with a first BN; and incrementing the PDU sequence number by the fixed value after the second ISO interval, wherein the second ISO interval is associated with a second BN different from the first BN.

[0178] Aspect 7: The method according to aspect 6, wherein, based on adjusting the number of transmission opportunities allocated for retransmission across ISO intervals, the first wireless device increments the PDU sequence number by a fixed value after each ISO interval regardless of the actual BN associated with the ISO interval.

[0179] Aspect 8: A method according to any one of Aspects 1 to 7, wherein, for each MCS among multiple MCSs, a mapping indicates a corresponding number of transmission opportunities allocated for retransmission, timing information associated with an adjustment of the corresponding number of transmission opportunities allocated for retransmission, and the size of the PDU.

[0180] Aspect 9: The method according to aspect 8, wherein, for each MCS, the control message further indicates the number of sub-events or the number of sub-intervals during the ISO interval.

[0181] Aspect 10: The method according to any one of Aspects 8 to 9 further includes: indicating the size of a PDU for a length hardening function at a first wireless device and a second wireless device; and based on the size of the PDU indicated to the length hardening function, reading an amount of data equal to the size of the PDU at each transmission opportunity of the ISO interval, so that each PDU received by the first wireless device has the same size, wherein the size of the PDU indicated to the length hardening function overrides a second size indicated by a header of the PDU.

[0182] Aspect 11: The method according to Aspect 10 also includes: using a majority voting algorithm to handle two or more failed attempts to decode a single PDU, wherein the majority voting algorithm is associated with the size indicated to the length hardening function, and wherein, if the majority voting algorithm detects a difference in the length field between the two or more failed attempts to decode the single PDU, the majority voting algorithm uses the size indicated to the length hardening function to correct the PDU.

[0183] Aspect 12: A method according to any one of Aspects 1 to 11, wherein the control message indicates a mapping between a corresponding number of transmission opportunities allocated for retransmission and a corresponding MCS for each of two different communication directions, the mapping comprising a first mapping for communication from a central device to a peripheral device and a second mapping for communication from a peripheral device to a central device.

[0184] Aspect 13: A method according to Aspect 12, wherein a mapping entry associated with the second mapping has a zero length when the reverse channel link from the peripheral device to the central device is disabled, and has a non-zero length when the reverse channel link from the peripheral device to the central device is enabled, and the sending or receiving of a control message dynamically enables or disables the reverse channel link depending on whether the mapping entry associated with the second mapping has a zero length or a non-zero length.

[0185] Aspect 14: A method according to any one of Aspects 1 to 13, wherein sending or receiving one or more audio data packets during the second ISO interval includes: sending one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets to a second wireless device based on the number of transmission opportunities allocated for retransmission, wherein the first wireless device is configured as a sending device and the second wireless device is configured as a receiving device.

[0186] Aspect 15: A method according to any one of Aspects 1 to 14, wherein sending or receiving one or more audio data packets during the second ISO interval includes: receiving one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets from a second wireless device based on the number of transmission opportunities allocated for retransmission, wherein the first wireless device is configured as a receiving device and the second wireless device is configured as a sending device.

[0187] Aspect 16: An apparatus for wireless communication at a first wireless device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of Aspects 1 to 15.

[0188] Aspect 17: An apparatus for wireless communication at a first wireless device, comprising at least one component for performing the method according to any one of aspects 1 to 15.

[0189] Aspect 18: A non-transitory computer-readable medium storing code for wireless communication at a first wireless device, the code comprising instructions executable by a processor to perform the method according to any one of aspects 1 to 15.

[0190] It should be noted that the methods described herein describe possible implementations, and that operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0191] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the specification may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0192] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration).

[0193] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted by a computer-readable medium. Other examples and implementations are within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination of these. Features that implement the functions may also be physically located at various locations, including portions that are distributed so that the functions are implemented at different physical locations.

[0194] Computer readable medium includes both non-transitory computer storage medium and communication medium, and communication medium includes any medium that facilitates computer program to be transmitted from one place to another place.Non-transitory storage medium can be any available medium that can be accessed by general or special computer.As an example and not limitation, non-transitory computer readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code parts and can be accessed by general or special computer or general or special processor any other non-transitory medium.In addition, any connection is appropriately referred to as computer readable medium.For example, if software is sent from website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology (such as infrared, radio and microwave), coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology (such as infrared, radio and microwave) are included in the definition of medium. As used herein, disk and disc include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks and Blu-ray discs where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0195] As used herein (including the claims), "or" as used in a list of items (e.g., a list of items ending with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0196] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference that distinguishes between the similar components. If only the first reference number is used in the specification, the description applies to any of the similar components having the same first reference number, regardless of the second or other subsequent reference numbers.

[0197] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that can be implemented or fall within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "better than other examples." The detailed description includes specific details for providing an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0198] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but is intended to conform to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for wireless communication at a first wireless device, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: sending or receiving a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmission via an isochronous stream of a connection and a respective modulation and coding scheme of the isochronous stream of the connection; detecting, during a first isochronous interval of the connected isochronous stream, a change to a modulation and coding scheme of the connected isochronous stream; adjusting, for a second isochronous interval of the isochronous flow of the connection, a number of transmission opportunities allocated for the retransmission based on detecting a change to the modulation and coding scheme and the mapping, wherein the first isochronous interval and the second isochronous interval span the same duration; as well as One or more audio data packets are transmitted or received with the second wireless device during the second isochronous interval according to the adjusted number of transmission opportunities allocated for the retransmission.

2. The device according to claim 1, wherein: The instructions for adjusting the number of transmission opportunities allocated for the retransmission are executable by the processor to cause the apparatus to: increasing a number of transmission opportunities allocated for the retransmissions as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme; as well as As the modulation and coding scheme increases from the relatively lower modulation and coding scheme to the relatively higher modulation and coding scheme, the number of transmission opportunities is reduced.

3. The device according to claim 1, wherein: The instructions for adjusting the number of transmission opportunities allocated for the retransmission are executable by the processor to cause the apparatus to: reducing a number of bursts associated with the isochronous flow of the connection as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme, wherein reducing the number of bursts is associated with an increase in a number of transmission opportunities allocated for the retransmissions; and As the modulation and coding scheme increases from the relatively lower modulation and coding scheme to the relatively higher modulation and coding scheme, the number of bursts associated with the isochronous stream of the connection is increased, wherein increasing the number of bursts is associated with a decrease in the number of transmission opportunities allocated for the retransmissions.

4. The device according to claim 1, wherein: The instructions for adjusting the number of transmission opportunities allocated for the retransmission are executable by the processor to cause the apparatus to: increasing a refresh timeout associated with the isochronous stream of the connection as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme, wherein increasing the refresh timeout is associated with an increase in a number of transmission opportunities allocated for the retransmissions; and As the modulation and coding scheme increases from the relatively lower modulation and coding scheme to the relatively higher modulation and coding scheme, reducing the refresh timeout associated with the isochronous flow of the connection, wherein reducing the refresh timeout is associated with a reduction in a number of transmission opportunities allocated for the retransmissions.

5. The device according to claim 1, wherein: tuning, for each of a plurality of modulation and coding schemes, a burst number associated with an isochronous flow of the connection, a refresh timeout associated with an isochronous flow of the connection, and a packet size, and The burst number, the refresh timeout, and the packet size are dynamically changed in response to changes to the modulation and coding scheme.

6. The device according to claim 1, wherein: The instructions are also executable by the processor to cause the apparatus to: After the first isochronous interval, incrementing the protocol data unit sequence number by a fixed value, wherein the first isochronous interval is associated with a first burst number; and The protocol data unit sequence number is incremented by the fixed value after the second isochronous interval, wherein the second isochronous interval is associated with a second burst number different from the first burst number.

7. The device according to claim 6, wherein: The first wireless device increments the protocol data unit sequence number by the fixed value after each isochronous interval in accordance with adjusting the number of transmission opportunities allocated for the retransmissions across isochronous intervals, regardless of an actual number of bursts associated with the isochronous interval.

8. The device according to claim 1, wherein: The mapping indicates, for each of a plurality of modulation and coding schemes, the respective number of transmission opportunities allocated for the retransmission, timing information associated with an adjustment to the respective number of transmission opportunities allocated for the retransmission, and a size of a protocol data unit.

9. The device according to claim 8, wherein: The control message also indicates the number of sub-events or the number of sub-intervals during the equal time interval for each modulation and coding scheme.

10. The device according to claim 8, wherein: The instructions are also executable by the processor to cause the apparatus to: indicating a size of the protocol data unit for a length hardening function at the first wireless device; as well as At each transmission opportunity at an equal time interval, an amount of data equal to the size of the protocol data unit is read based on the size of the protocol data unit indicated to the length hardening function, so that each protocol data unit received by the first wireless device has the same size, wherein the size of the protocol data unit indicated to the length hardening function overrides a second size indicated by a header of the protocol data unit.

11. The device according to claim 10, wherein: The instructions are also executable by the processor to cause the apparatus to: Two or more failed attempts to decode a single protocol data unit are processed using a majority voting algorithm, wherein the majority voting algorithm is associated with a size indicated to the length hardening function, and wherein, if the majority voting algorithm detects a difference in length fields across the two or more failed attempts to decode the single protocol data unit, the majority voting algorithm corrects the protocol data unit using the size indicated to the length hardening function.

12. The device according to claim 1, wherein: The control message indicates a mapping between the corresponding number of transmission opportunities allocated for the retransmission and the corresponding modulation and coding scheme for each of two different communication directions, and wherein the mapping includes a first mapping for communication from a central device to a peripheral device and a second mapping for communication from the peripheral device to the central device.

13. The device according to claim 12, wherein: A mapping entry associated with the second mapping has a zero length when a reverse channel link from the peripheral device to the central device is disabled, and has a non-zero length when the reverse channel link from the peripheral device to the central device is enabled, and wherein sending or receiving the control message dynamically enables or disables the reverse channel link depending on whether the mapping entry associated with the second mapping has the zero length or the non-zero length.

14. The device according to claim 1, wherein: The instructions for transmitting or receiving the one or more audio data packets during the second isochronous interval are executable by the processor to cause the apparatus to: The one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets are sent to the second wireless device based on a number of transmission opportunities allocated for the retransmissions, wherein the first wireless device is configured as a transmitting device and the second wireless device is configured as a receiving device.

15. The device according to claim 1, wherein: The instructions for transmitting or receiving the one or more audio data packets during the second isochronous interval are executable by the processor to cause the apparatus to: The one or more audio data packets and a potential set of one or more retransmissions of the one or more audio data packets are received from the second wireless device based on a number of transmission opportunities allocated for the retransmissions, wherein the first wireless device is configured as a receiving device and the second wireless device is configured as a transmitting device.

16. A method for wireless communication at a first wireless device, comprising: sending or receiving a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmission via an isochronous stream of a connection and a respective modulation and coding scheme of the isochronous stream of the connection; detecting, during a first isochronous interval of the connected isochronous stream, a change to a modulation and coding scheme of the connected isochronous stream; adjusting, for a second isochronous interval of the isochronous flow of the connection, a number of transmission opportunities allocated for the retransmission based on detecting a change to the modulation and coding scheme and the mapping, wherein the first isochronous interval and the second isochronous interval span the same duration; as well as One or more audio data packets are transmitted or received with the second wireless device during the second isochronous interval according to the adjusted number of transmission opportunities allocated for the retransmission.

17. The method according to claim 16, wherein: Adjusting the number of transmission opportunities allocated for the retransmission comprises: increasing a number of transmission opportunities allocated for the retransmissions as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme; and As the modulation and coding scheme increases from the relatively lower modulation and coding scheme to the relatively higher modulation and coding scheme, the number of transmission opportunities is reduced.

18. The method according to claim 16, wherein: Adjusting the number of transmission opportunities allocated for the retransmission includes: reducing a number of bursts associated with the isochronous flow of the connection as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme, wherein reducing the number of bursts is associated with an increase in a number of transmission opportunities allocated for the retransmissions; and As the modulation and coding scheme increases from a relatively lower modulation and coding scheme to a relatively higher modulation and coding scheme, increasing the number of bursts associated with the isochronous stream of the connection, wherein increasing the number of bursts is associated with a decrease in the number of transmission opportunities allocated for the retransmissions.

19. The method according to claim 16, wherein: Adjusting the number of transmission opportunities allocated for the retransmission includes: increasing a refresh timeout associated with the isochronous stream of the connection as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme, wherein increasing the refresh timeout is associated with an increase in a number of transmission opportunities allocated for the retransmissions; and As the modulation and coding scheme increases from a relatively lower modulation and coding scheme to a relatively higher modulation and coding scheme, a refresh timeout associated with the isochronous flow of the connection is reduced, wherein reducing the refresh timeout is associated with a reduction in a number of transmission opportunities allocated for the retransmissions.

20. The method according to claim 16, wherein: For each of a plurality of modulation and coding schemes, a burst number associated with an isochronous stream of the connection, a refresh timeout associated with the isochronous stream of the connection, and a packet size are tuned, and wherein the burst number, the refresh timeout, and the packet size are dynamically changed in response to a change to the modulation and coding scheme.

21. The method of claim 16, further comprising: After the first isochronous interval, incrementing the protocol data unit sequence number by a fixed value, wherein the first isochronous interval is associated with a first burst number; and The protocol data unit sequence number is incremented by the fixed value after the second isochronous interval, wherein the second isochronous interval is associated with a second burst number different from the first burst number.

22. The method according to claim 21, wherein: The first wireless device increments the protocol data unit sequence number by the fixed value after each isochronous interval in accordance with adjusting the number of transmission opportunities allocated for the retransmissions across isochronous intervals, regardless of an actual number of bursts associated with the isochronous interval.

23. The method according to claim 16, wherein: The mapping indicates, for each of a plurality of modulation and coding schemes, a respective number of transmission opportunities allocated for the retransmission, timing information associated with an adjustment to the respective number of transmission opportunities allocated for the retransmission, and a size of a protocol data unit.

24. The method according to claim 23, wherein: The control message also indicates the number of sub-events or the number of sub-intervals during the equal time interval for each modulation and coding scheme.

25. The method of claim 23, further comprising: indicating a size of the protocol data unit for a length hardening function at the first wireless device; as well as At each transmission opportunity at an equal time interval, an amount of data equal to the size of the protocol data unit is read based on the size of the protocol data unit indicated to the length hardening function, so that each protocol data unit received by the first wireless device has the same size, wherein the size of the protocol data unit indicated to the length hardening function overrides a second size indicated by a header of the protocol data unit.

26. The method according to claim 25, further comprising: Two or more failed attempts to decode a single protocol data unit are processed using a majority voting algorithm, wherein the majority voting algorithm is associated with a size indicated to the length hardening function, and wherein, if the majority voting algorithm detects a difference in length fields across the two or more failed attempts to decode the single protocol data unit, the majority voting algorithm corrects the protocol data unit using the size indicated to the length hardening function.

27. An apparatus for wireless communication at a first wireless device, comprising: means for sending or receiving a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmissions via an isochronous stream of a connection and a respective modulation and coding scheme of the isochronous stream of the connection; means for detecting, during a first isochronous interval of said connected isochronous stream, a change to a modulation and coding scheme of said connected isochronous stream; means for adjusting the number of transmission opportunities allocated for said retransmissions in accordance with a detected change to said modulation and coding scheme and said mapping for a second isochronous interval of an isochronous flow of said connection, wherein said first isochronous interval and said second isochronous interval span the same duration; as well as Means for transmitting or receiving one or more audio data packets with a second wireless device during the second isochronous interval in accordance with the adjusted number of transmission opportunities allocated for the retransmission.

28. The device according to claim 27, wherein The means for adjusting the number of transmission opportunities allocated for the retransmission comprises: means for increasing the number of transmission opportunities allocated for said retransmissions as said modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme; and means for reducing the number of transmission opportunities as the modulation and coding scheme increases from the relatively lower modulation and coding scheme to the relatively higher modulation and coding scheme.

29. The device according to claim 27, wherein: The means for adjusting the number of transmission opportunities allocated for the retransmission comprises: means for reducing a number of bursts associated with the isochronous stream of the connection as the modulation and coding scheme decreases from a relatively higher modulation and coding scheme to a relatively lower modulation and coding scheme, wherein reducing the number of bursts is associated with an increase in a number of transmission opportunities allocated for the retransmissions; and means for increasing the number of bursts associated with the isochronous stream of the connection as the modulation and coding scheme increases from the relatively lower modulation and coding scheme to the relatively higher modulation and coding scheme, wherein increasing the number of bursts is associated with a decrease in the number of transmission opportunities allocated for the retransmissions.

30. A non-transitory computer readable medium storing code for wireless communication at a first wireless device, the code comprising instructions executable by a processor to: sending or receiving a control message indicating a mapping between a respective number of transmission opportunities allocated for retransmission via an isochronous stream of a connection and a respective modulation and coding scheme of the isochronous stream of the connection; detecting, during a first isochronous interval of the connected isochronous stream, a change to a modulation and coding scheme of the connected isochronous stream; adjusting, for a second isochronous interval of the isochronous flow of the connection, a number of transmission opportunities allocated for the retransmission based on detecting a change to a modulation and coding scheme and the mapping, wherein the first isochronous interval and the second isochronous interval span the same duration; as well as One or more audio data packets are transmitted or received with the second wireless device during the second isochronous interval according to the adjusted number of transmission opportunities allocated for the retransmission.

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