CROSS REFERENCES TO RELATED APPLICATIONS

[0001] This application claims priority to US Provisional Patent Application No. 63/419,878. entitled “Dynamically Using Bluetooth Classic Or LE Technology Usage Based On The Regulatory Domain,” filed October 27, 2022, the entire disclosure of which is hereby incorporated by reference for all purposes.

[0002] This application also claims priority to US Provisional Patent Application No. 63/440,047. entitled “Bluetooth Communication Improvements,” filed January 19, 2023, the entire disclosure of which is hereby incorporated by reference for all purposes.

BACKGROUND

[0003] A strong link margin is preferrable for wireless communications. For example, when a user is using earbuds that communicate with another device, a larger link margin makes the wireless communication more tolerant to attenuation. By being more tolerant to attenuation, the user can have a better experience. An increased link margin can allow the earbuds (and thus the user) to be at a greater distance from the other device. Further, situations that cause meaningful attenuation, such as cross-body attenuation, are less likely to affect the user experience.

SUMMARY

[0004] Various embodiments are described related to a method for improving wireless link margin. In some embodiments, a method for improving wireless link margin is described. The method may comprise determining a location of an audio source device. The method may comprise, based on the location of the audio source device, selecting a domain mapping from a plurality of domain mappings. The method may comprise, based on the selected domain mapping, selecting a communication protocol for wireless communication between the audio source device and an audio output device. The method may comprise transmitting, by the audio source device to the audio output device, audio data using the selected communication protocol.

[0005] Embodiments of such a method may include one or more of the following features: the communication protocol may be selected from the group consisting of Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and Bluetooth Low Energy (LE). The communication protocol selected may be Bluetooth BR/EDR. The location may be determined based on an identifier received from a cellular network. The location may be determined based on an identifier received from a wireless local area network. Selecting the communication protocol for wireless communication between the audio source device and the audio output device may be based on which communication protocol results in a greater link margin for wireless communication between the audio source device and the audio output device. The method may further comprise determining a use type from a plurality of predefined use types for the audio data to be transmitted. The communication protocol may be further selected based on the determined use type. The audio source device may be a smartphone and the audio output device may be a pair of true wireless earbuds. The pair of true wireless earbuds may be configured to wirelessly communicate using Bluetooth BR/EDR and Bluetooth LE.

[0006] In some embodiments, a wireless communication system is described. The system may comprise a first earbud, comprising a first speaker, a first processing system, and a first wireless communication interface, that may wirelessly communicate with an audio source device. The system may comprise a second earbud, comprising a second speaker, a second processing system, and a second wireless communication interface, that may wirelessly communicate with the audio source device. The system may comprise the audio source device that may wirelessly communicate with the first earbud and the second earbud. The wireless communication system may be configured to determine a location of the audio source device. The system may be configured to, based on the location of the audio source device, select a domain mapping from a plurality of domain mappings. The system may be configured to, based on the selected domain mapping, select a communication protocol for wireless communication between the audio source device and the first earbud and for wireless communication between the audio source device and the second earbud. The system may be configured to transmit and receive, between the audio source device and the first earbud and the second earbud, audio data using the selected communication protocol.

[0007] Embodiments of such a system may include one or more of the following features: the communication protocol may be selected from the group consisting of Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and Bluetooth Low Energy (LE). The communication protocol selected may be Bluetooth BR/EDR. The location may be determined based on an identifier received from a cellular network or from a wireless local area network. The wireless communication system being configured to select the communication protocol for wireless communication between the audio source device and the first and second earbuds may be based on which communication protocol results in a greater link margin for wireless communication between the audio source device and the first and second earbuds. The system may further comprise determining a use type from a plurality of predefined use types for the audio data to be transmitted. The communication protocol may be further selected based on the determined use type. [0008] In some embodiments, an audio source device is described. The device may comprise a wireless communication interface. The device may comprise a non-transitory processor-readable medium that stores a plurality of domain mappings. The device may comprise a processing system comprising one or more processors, where the processing system may be configured to determine a location of the audio source device. The processing system may be configured to, based on the location of the audio source device, select a domain mapping from the plurality of domain mappings. The processing system may be configured to, based on the selected domain mapping, select a communication protocol for wireless communication between the audio source device and an audio output device. The processing system may be configured to transmit and receive, via the wireless communication interface, audio data using the selected communication protocol. The communication protocol may be selected from the group consisting of Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) and Bluetooth Low Energy (LE). The communication protocol selected may be Bluetooth BR/EDR. Selecting the communication protocol for wireless communication between the audio source device and the audio output device may be based on which communication protocol results in a greater link margin for wireless communication between the audio source device and the audio output device.

BRIEF DESCRIPTION OF THE FIGURES

[0009] A further understanding of the nature and advantages of various embodiments may be realized by reference to the following figures. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0010] FIG. 1A illustrates an embodiment of an audio system.

[0011] FIG. IB illustrates another embodiment of an audio system.

[0012] FIG. 2 illustrates an embodiment of a block diagram of an audio system that includes a pair of true wireless earbuds communicating with an audio source.

[0013] FIG. 3 illustrates an embodiment of cross-body attenuation resulting in communication between an audio source and a first earbud experiencing more attenuation than communication between the audio source and the second earbud. [0014] FIG. 4 illustrates an embodiment of an audio system in which true wireless earbuds communicate with each other in addition to communicating with an audio source.

[0015] FIG. 5 illustrates an embodiment of a table that indicates how link margin can vary by communication technology and regulatory domain.

[0016] FIG. 6 illustrates an embodiment of a method for improving wireless link margin.

[0017] FIG. 7 illustrates another embodiment of a method for improving wireless link margin.

DETAILED DESCRIPTION

[0018] Having as large of a link margin as possible between devices that are communicating wirelessly is desirable. “Link margin” is the difference between the received signal power and the signal power required for a certain quality of service. It is a measure of how much signal attenuation the link can tolerate before it becomes unusable. Link margin is typically expressed in decibels (dB). A positive link margin means that the communication link has more signal power than it needs, while a negative link margin means that the link does not have enough signal power to be received. The link margin can be calculated by taking the difference between the received signal power and the required signal power. The received signal power is determined by such factors as the transmitter power and the transmitter’s antenna gain. The required signal power is determined by the receiver sensitivity and the modulation and coding scheme. As example, a 25 dB link margin means that 25 dB of attenuation between the transmitter and the receiver can be tolerated with the receiver still successfully receiving the transmitted signal. Therefore, as the link margin is increased, the amount of attenuation that can be tolerated similarly increases. As an example, by the link margin being greater, a user that is wearing wireless earbuds to receive audio or conduct a telephone call can move farther away from their smartphone from which the audio data is being transmitted.

[0019] However, the amount of power used to transmit cannot be arbitrarily increased. First, devices that use wireless communication tend to receive power from a battery. Thus, increasing the amount of transmit power results in additional power use by the transmitting device. Second, depending on where the wireless communication is occurring, a regulatory body may set a limit on the maximum transmit power. Regulatory bodies tend to set varying limits on maximum transmit power. Therefore, if a transmitting device is moved from the jurisdiction of a first regulatory body (e.g., the Federal Communications Commission (FCC) in the United States) to a jurisdiction of a second regulatory body (e.g., European Telecommunications Standards Institute (ETSI) in Europe), the transmitting device is required to comply with the local regulations. [0020] To further complicate matters, the permissible transmit power set by a regulatory agency can be defined in terms of spectral density. For example, the maximum transmit power of a jurisdiction could be defined as 10 dBm/MHz power spectral density (PSD). Different communication technologies, based on the maximum transmit power and how the protocol operates, can result in significantly different link margins being present between the same transmitting device and same receiving device depending on the communication technology used and the regulatory domain.

[0021] Embodiments detailed herein are directed to varying the communication technology used, such as switching between Bluetooth Basic Data Rate / Extended Data Rate (BDR/EDR) and Bluetooth Low Energy (LE) depending on the use type and regulatory domain to obtain the greatest link margin that is permissible within the jurisdiction.

[0022] Detail regarding these embodiments and others are provided in relation to the figures. FIGS. 1A and IB illustrate embodiments of an audio system. As shown in FIG. 1 A, audio system 100 A can include earbuds 110 (which can include earbud 110-1 and earbud 110-2), audio source device 120, and audio source 130, and, as shown in FIG. IB, audio system 100B can include earbuds 110, audio source device 120, and accessory devices 140 (which can include multiple accessory devices 140-1, . . . 140-N). (Although not shown, audio system 100A can also include accessory devices such as accessory devices 140.) Similarly, audio system 100B can also include additional audio sources such as audio source 130.

[0023] While embodiments detailed herein focus on earbuds 110 as the audio output device, it should be understood that alternative forms of wireless audio output devices can used in various embodiments of the systems and methods. For example, a wireless portable speaker may be used as the audio output device. As another option, wireless headphones or a wireless hearing aid may be used. When earbuds are used, the earbuds can be a pair of true wireless earbuds. “True wireless earbuds,” as used herein, refer to earbuds that both: 1) receive audio packets wirelessly from one or more audio sources; and 2) are not physically connected with each other, such as via a wire. Therefore, in a pair of true wireless earbuds, each earbud must have its own power supply and wireless communication interface to allow for communication.

[0024] Audio source device 120 can represent various forms of computerized devices capable of short-range wireless communication, such as Bluetooth communications. As illustrated, one possible form of audio source device 120 is a smartphone. For example, a smartphone can output stereo audio (e.g., music, gaming audio, audio for an audio or video conference) and mono audio (e.g., audio for a telephone call, mono audio for an audio or video conference). Many other forms of audio source device 120 may be possible, such as: a tablet computer, a gaming device, a laptop computer, a desktop computer, a stereo system, and a television. More generally, any computerized device that outputs Bluetooth audio can serve as audio source device 120. In some embodiments, audio source device 120, when used for voice phone calls, can alternatively be used as and referred to as a call gateway. (In voice call terminology, earbuds 110 can be referred to as a “call terminal.”)

[0025] In general, as detailed herein, Bluetooth-family protocols are used as the short-range wireless technology standards for exchanging data between audio source device 120 (and possibly audio source 130) and earbuds 110 and between audio source device 120 and accessory devices 140. Within the Bluetooth-family, various versions of Bluetooth may be used, depending on the particular embodiment. Bluetooth Basic Rate/Enhanced Data Rate (Bluetooth BR/EDR), which is also referred to as Bluetooth “Classic,” can be used in various embodiments as detailed herein. Bluetooth Low Energy (LE) or LE Audio can be used as the specific Bluetooth-family protocol for communication. The same hardware may be used to implement any of these Bluetooth-family protocols.

[0026] Depending on the version of Bluetooth that is used, one or more Bluetooth profiles may be used to define a connection/communication protocol between a central (or first) device and peripheral (or second) device(s) and between peripheral devices. For example, the connection/communication protocol between the audio source device 120 and earbuds 110 may be defined by the Advanced Audio Distribution Profile (A2DP) and/or the Hands-Free Profile (HFP). Similarly, the connection/communication protocol between the audio source device 120 and the accessory devices 140 may be defined by the Human Interface Device (HID) Profile. The foregoing profiles are not intended to be limiting and the various embodiments described herein can use other Bluetooth profiles such as the Headset Profile (HSP) and the Mesh Profile (MESH).

[0027] Further, embodiments detailed herein may use one or more of these Bluetooth-family protocols as a starting point but may have additional features that go beyond the specification of the standard. These additional features require both an audio source and earbuds that are compatible with the additional features to be used in order for the additional features to be available. As an example, one manufacturer may produce earbuds and audio sources (e.g., smartphones, laptop computers, tablet computers) that support additional features that go beyond the minimum features of a Bluetooth-family protocol when used together. However, when one of such devices is used with another manufacturer’s devices, such additional features beyond the Bluetooth-family may not be available unless the manufacturers have cooperated on implementing the additional features.

[0028] While the embodiments detailed herein are focused on improvements to Bluetoothfamily protocols, it should be understood that the embodiments detailed herein can also be applied to other short-range wireless technologies that could be used to enable communication between devices. For example, the embodiments detailed herein are equally applicable to the following technologies: infrared data association (IrDA); radio frequency identification (RFID); wireless local access network (WLAN); near field communication (NFC); ZigBee; Z-wave; wireless fidelity (Wi-Fi) and wireless fidelity direct (Wi-Fi Direct); ultra-wideband (UWB); ANT and ANT+; third generation (3G), fourth generation (4G), fifth generation (5G), and sixth generation (6G), and the like.

[0029] As illustrated in FIG. 1 A, separate data streams may be used between an audio source and each earbud of earbuds 110. In a Bluetooth LE or LE Audio scenario, a connected isochronous stream (CIS) or broadcast isochronous stream (BIS) may be present on link 121 from audio source device 120 to earbud 110-1. A separate CIS or BIS may be present as part of link 122 to earbud 110-2. If audio is being transmitted from an earbud of earbuds 110 to audio source device 120 (e.g., from a microphone of an earbud for a phone call), another CIS or BIS may be present from an earbud to audio source device 120. Alternatively, the same CIS or BIS can be used for transmitting microphone audio from an earbud to audio source device 120. Separate CISs or BISs may also exist as part of wireless communications 131 and wireless communications 132 between an additional audio source such as audio source 130 and earbuds 110. Separately, between each audio source and each earbud, can be another channel, referred to as an asynchronous connection- oriented link (ACL) that allows for control data to be transmitted between the audio source and the particular earbud in both directions.

[0030] While one or more active communication channels are present between audio source device 120 and earbuds 110, one or more separate active communication channels can be present between earbuds 110 and audio source 130. Again here many other audio sources may be possible, such as: a tablet computer, a gaming device, a laptop computer, a desktop computer, a computerized music device, a stereo system, a television, or any computerized device that can output Bluetooth audio can serve as audio source 130.

[0031] Various use types exist where it can be beneficial to a user for earbuds 110 to have communication channels with multiple audio sources. For example, earbuds 110 may receive audio from a computer (e.g., as audio source device 120) for a video conference, but the user may desire to allow his smartphone (e.g., as audio source 130) to output notifications that are played instead of or over the audio for the video conference. As another example, a user may be listening to music via their smartphone (e.g., as audio source device 120), while listening to the music, the user may be in a public place that outputs auditory notifications via Bluetooth, such as flight notifications at an airport. A computerized system of the airport may function as audio source 130 which causes flight notifications to be output instead of or over the audio being streamed to earbuds 110 by audio source device 120.

[0032] Notably, audio source 130 may not be present in many embodiments or may only be intermittently present. Referring to the previous example, after leaving the airport (or perhaps disabling notifications), earbuds 110 may only receive audio from audio source device 120. Other similar examples exist. For example, referring to the first example, after conclusion of the video conference, earbuds 110 may only receive audio (e.g., the auditory notifications) from their smartphone. While the example of FIG. 1A illustrates two audio sources, it may be possible for earbuds 110 to receive audio from more than two audio sources. Earbuds 110 may be configured to prioritize and/or mix audio received concurrently from different audio sources.

[0033] For mono audio (e.g., a phone call, videoconference), the audio transmitted to one or each earbud of earbuds 110 from an audio source, such as audio source device 120, may be the same. For stereo audio (e.g., music playback, gaming), the audio transmitted to one or each earbud of earbuds 110 differs.

[0034] Referring to FIG. IB, data may be transmitted between an audio source device 120 and a primary earbud such as earbud 110-1 of earbuds 110 and data may be transmitted between the primary earbud 110-1 and a secondary earbud such as earbud 110-2. In a Bluetooth Classic scenario, data may be transmitted using a synchronous connection-oriented (SCO) channel or extended synchronous connection-oriented (eSCO) channel that may be present on link 123 between audio source device 120 and primary earbud 110-1 and data may be transmitted using an ACL that may be present on link 150 between primary earbud 110-1 and secondary earbud 110-2. In some embodiments, the data on link 123 and/or link 150 can include audio or voice data. Control data can be transmitted in both directions using link 124, which can be an ACL link.

Control data as used herein generally refers to information pertaining to the link between the audio source device 120 and primary earbud 110-1 and link between primary earbud 110-1 and the secondary earbud 110-2 (e.g., physical layer properties, timing information, encryption keys, power requirements, and the like). If audio is being transmitted from an earbud of earbuds 110 to audio source device 120 (e.g., from a microphone of an earbud for a phone call), the SCO or eSCO link may be used and/or another SCO or eSCO link (not shown) may be used. Separate links may also respectively exist as part of wireless communications 141-1 through wireless communications 141-N between audio source device 120 and accessory devices 140-1 through 140-N. In some embodiments, these links may be a link defined by the HID Profile under the Bluetooth core specification.

[0035] While one or more active communication channels are present between audio source device 120 and earbuds 110, one or more separate active communication channels can be present between audio source device 120 and accessory devices 140. Accessory device 140 can represent various forms of computerized devices capable of communicating and exchanging data using Bluetooth connections. One example of an accessory device included in accessory devices 140 is a wireless keyboard and another example of an accessory device included in accessory devices 140 is a wireless mouse. Other examples of accessory devices include human interface devices, printers, scanners, network devices, gaming devices, display assistants, and the like. In general, any computerized device that can communicate using Bluetooth can serve as an accessory device included in accessory devices 140. In some embodiments, an accessory device included in accessory devices 140 can be used as and referred to as a peripheral and/or human interface device.

[0036] In some embodiments, communication between earbuds 110 and audio source device 120 can be an acknowledgement, referred to as an ACK for short. An ACK can allow one of or both earbuds 110 to notify the audio source device 120 that a Bluetooth packet was properly received from the audio source device 120. Similarly, an ACK can allow the audio source device 120 to notify one of or both earbuds 110 that a Bluetooth packet was properly received from one of or both earbuds. An ACK and data packets between earbuds can be sent using the same radio used for Bluetooth communications. At a high level, when a packet addressed to a first earbud, such as earbud 110-1, and is properly received by earbud 110-1, earbud 110-1 can transmit an ACK to the audio source device 120. This arrangement can prevent the audio source device 120 from retransmitting the packet to the earbud 110-1 and/or can allow the earbud 110-1 to transmit the packet to the second earbud 110-2 if the second earbud 110-2 cannot intercept and/or otherwise acquire the packet transmitted from the audio source device 120. While an ACK is one form of communication that can occur between audio source device 120 and earbuds 110, other communications detailed herein between earbuds may not involve an ACK being transmitted.

[0037] FIG. 2 illustrates an embodiment of a block diagram of an audio system 200 that includes a pair of true wireless earbuds communicating with an audio source. Audio system 200 can represent an embodiment of audio system 100A in which only a single audio source is present or audio system 100B. Audio system 200 can include earbuds 110 and audio source device 120.

[0038] Referring to earbuds 110, components of earbud 110-1 can include: antenna 210; wireless communication interface 220; processing system 230; microphone 240; and speaker 250. Earbud 110-2 may have the same components. Antenna 210 can be used for receiving and transmitting Bluetooth-family communications, including BR/EDR, and LE (including LE Audio which uses LE). Wireless communication interface 220 can be implemented as a system on a chip (SOC). Wireless communication interface 220 can include a Bluetooth radio and componentry necessary to convert raw incoming data (e.g., audio data, other data) to Bluetooth packets for transmission via antenna 210. Wireless communication interface 220 may also include componentry to enable one or more alternative or additional forms of wireless communication, both with an audio source and between earbuds. Processing system 230 may include one or more special-purpose or general -purpose processors. Such special-purpose processors may include processors that are specifically designed to perform the functions of the components detailed herein. Such special-purpose processors may be ASICs or FPGAs which are general-purpose components that are physically and electrically configured to perform the functions detailed herein. Such general-purpose processors may execute special-purpose software that is stored locally using one or more non-transitory processor-readable mediums, such as random-access memory (RAM), and/or flash memory. In some embodiments, processing system 230 and wireless communication interface 220 may be part of a same circuit or SOC.

[0039] In some earbuds, microphone 240 may be present. In some embodiments, each of earbuds 110 has a microphone. In other embodiments, only one of earbuds 110 has a microphone. In still other embodiments, no microphone may be present in either of earbuds 110. Audio captured using the one or more microphones of earbuds 110 can be transmitted to audio source device 120. This audio, which can be referred to as “upstream” audio, may include voice, such as for use in a telephone call, video conference, gaming, etc. Various componentry (not illustrated) may be present between wireless communication interface 220, processing system 230, and microphone 240, such as an analog to digital converter (ADC) and an amplifier.

[0040] Speaker 250 converts received analog signals to audio. Various componentry (not illustrated) may be present between wireless communication interface 220, processing system 230, and speaker 250, such as a digital to analog converter (DAC) and an amplifier.

[0041] Various components of earbud 110-1 are not illustrated. In addition to the ADC, DAC, and amplifiers previously mentioned, earbud 110-1 also includes a power storage component, such as one or more batteries, and associated componentry to allow for recharging of the power storage component. Also present is a housing and componentry to hold earbud 110-1 within a user’s ear. One or more non-transitory processor readable mediums can be understood as present and accessible by wireless communication interface 220, processing system 230, or both. For instance, such mediums may be used for temporary storage of data (e.g., buffers) and storing data necessary for Bluetooth communication (e.g., encryption keys).

[0042] Audio source device 120 can include: antenna 260; wireless communication interface 270; processing system 280; and data storage 290. Antenna 260 can be used for receiving and transmitting Bluetooth-family communications, including BR/EDR, and LE. Wireless communication interface 270 can be implemented as a SOC. Wireless communication interface 270 can include a Bluetooth radio and componentry necessary to convert raw incoming data (e.g., audio data, other data) to Bluetooth packets for transmission via antenna 260. Wireless communication interface 270 can additionally or alternatively be used for one or more other forms of wireless communications. For example, wireless communication interface 270 can include hardware, such as including radios, antennas, and modems to communicate with other forms of wireless networks, such as wireless local area networks (e.g., WiFi networks) and/or cellular networks (e.g., 3G, 4G, 5G, and beyond). Processing system 280 may include one or more specialpurpose or general-purpose processors. Such special-purpose processors may include processors that are specifically designed to perform the functions of the components detailed herein. Such special-purpose processors may be ASICs or FPGAs which are general-purpose components that are physically and electrically configured to perform the functions detailed herein. Such general- purpose processors may execute special-purpose software that is stored locally using one or more non-transitory processor-readable mediums via data storage 290, which can include RAM, flash memory, a HDD and/or a SSD. In some embodiments, processing system 280 and wireless communication interface 270 may be part of a same circuit or SOC. As detailed herein, data storage 290 can used to store various domain mappings which are used to correlate which communication protocol should be used and at which transmit power depending on the current regulatory domain.

[0043] Audio source device 120 can include various other components. For example, if audio source device 120 is a smartphone, various components such as: one or more cameras, a display screen or touch screen, volume control buttons, other wireless communication interfaces can be present. [0044] As previously noted, having a greater link margin is preferrable in order to prevent attenuation from negatively affecting the ability of the audio output device, such as earbuds 110, from properly receiving audio from audio source device 120 (and, possibly, the reverse direction, such as for the transmission of acknowledgements and/or audio data based on audio captured using microphone 240). FIG. 3 illustrates an embodiment 300 of cross-body attenuation resulting in communication between an audio source and a first earbud experiencing more attenuation (or path loss) than communication between the audio source and the second earbud. In embodiment 300, user 301 is holding audio source device 120 in their left hand (that is, as illustrated, user 301 is facing out of the page). Bluetooth communications occur between audio source device 120 and earbud 110-2 as indicated by link 122; Bluetooth communications between audio source device 120 and earbud 110-1 as indicated by link 121.

[0045] Due to audio source device 120 being in the user’s left hand, link 121 with earbud 110-1, which is in the user’s right ear, results in wireless signals travelling through more of the user’s body than link 122. Therefore, more attenuation occurs in link 121 than link 122. Accordingly, it is more likely that Bluetooth data packets exchanged between earbud 110-1 and audio source device 120 may not be properly received than Bluetooth data packets exchanged between earbud 110-2 and audio source device 120.

[0046] Which earbud experiences more attenuation and/or interference in its communications with an audio source can vary based on the location of audio source device 120. Common places where user 301 may keep audio source device 120 are: in a left hand; in a right hand; in a front left or right pocket, in a rear left or right pocket; on an arm band; in a left or right chest pocket; and on a surface or dock. Each of these locations can result in significantly different communication paths between each earbud and the antenna of the audio source and, thus, one earbud’s communications can experience significantly higher interference or attenuation than the other earbud’s communications.

[0047] FIG. 4 illustrates an embodiment of an audio system 400 in which true wireless earbuds communicate with each other in addition to communicating with an audio source. Earbud 110-1 can perform wireless communications using cross-link 410 with earbud 110-2 and, similarly, earbud 110-2 can perform wireless communications using cross-link 410 with earbud 110-1 in some embodiments. This communication can occur via a proprietary link specific to earbuds 110 and therefore can be outside of any Bluetooth family protocol specification. The path between earbuds 110, when in use by user 301, is predictable because the distance and the object through which the signals pass (the head of user 301) remains constant. As detailed herein, the ability of earbuds 110 to communicate with each other can have significant advantages.

[0048] Cross-link 410 can use LE IM, LE 2M, LE HDT (pending standardization), LE proprietary high data rate modes, classic BR/EDR, or some proprietary communication scheme. Therefore, while Bluetooth-compliant wireless communications occur between earbuds 110 and audio source device 120, communications directly between earbuds do not necessarily need to be compliant with Bluetooth or any other particular communication protocol.

[0049] In some embodiments, communication between earbuds 110 can be a crossacknowledgement, referred to as a CrossACK for short. As detailed herein, “cross-” communications refer to wireless communications transmitted directly from a first earbud and received by a second earbud. A CrossACK can allow one of earbuds 110 to notify the other earbud of earbuds 110 that a Bluetooth packet was properly received from a source device. A CrossACK and data packets between earbuds can be sent using the same radio used for Bluetooth communications. At a high level, when a packet addressed to only a first earbud is not properly received by the first earbud, but is properly received by the second earbud, the second earbud can transmit a CrossACK to the first earbud. The first earbud may then request the packet be relayed to the first earbud from the second earbud. This arrangement prevents the first earbud from having to request retransmission from the source device and/or can allow the first earbud to obtain the data from the second earbud if transmissions from the audio source continue to fail. While a CrossACK is one form of communication that can occur between earbuds 110, other communications detailed herein between earbuds may not involve a CrossACK being transmitted.

[0050] Notably, while the description contained herein focuses on Bluetooth and Bluetoothfamily protocols including LE Audio, the same principles detailed herein can be applied to other short-range wireless communication protocols.

[0051] As previously detailed, the transmit power that can be used to transmit a wireless signal can vary by regulatory domain. Depending on the wireless communication protocol (also referred to as the wireless communication technology) and bandwidth over which communications are made, these regulatory power limitations can result in differing link margins, even if the same hardware is used for signal transmission and reception for different communication protocols. FIG. 5 illustrates an embodiment of a table 500 that indicates how link margin can vary by wireless communication technology and regulatory domain. As an example, audio source (AS) can refer to audio source device 120 and output device (OD) can refer to earbuds 110 (or some other form of audio output device, such as a portable wireless speaker). [0052] If the audio output device and the audio source device are both capable of performing Bluetooth LE communications, Bluetooth LE may be used for communication. For example, Bluetooth LE based communication uses less power and has a lower latency than Bluetooth Classic. In contrast, embodiments detailed herein can use a different Bluetooth-family communication protocol based on the regulatory domain within which the audio source device is located. Referring to table 500, C may be significantly larger than G. That is, by using Bluetooth Classic for communication when under the jurisdiction of the ETSI, a significantly larger link margin may be realized, such as an increase of 12.5 dB in link margin. Similarly, D may be larger than H, thus resulting in a larger link margin for data transfer from the audio output device to the audio source device.

[0053] However, while C may be significantly larger than G, when the regulatory domain is changed, the comparison can result in a different communication protocol having the greater link margin. For example, if under the jurisdiction of the FCC, E can be greater than A, while B and F may be the same or very similar. Therefore, in this example, while under the jurisdiction of the FCC, a greater link margin results from using Bluetooth LE as the communication protocol instead of Bluetooth Classic.

[0054] Along with radio performance (e.g., transmit power, sensitivity, etc.), link margin can also depend on Medium Access Control (MAC) layer performance. The MAC layer can use different packet types to transmit and/or receive the data for different use cases. Some packet types can use forward error correction (FEC) codes while others may not use any FEC. Additionally, if FEC is used then the FEC rates could be different. The receiver performance can improve if FEC is used in comparison to when no FEC is used. The improvement corresponds to the FEC rate being used. Such arrangements lead to different link margin for different use cases. As an example, for music playback, a unidirectional data flow is present with only acknowledgements being sent by the audio output device to the audio source. Data sent to the audio output device by the audio source can use enhanced data rate 2 (EDR2) packets, while acknowledgements from the audio output device use basic rate (BR) packets. The particular BR packets used can have 1/3 FEC coding, which provides better link margin compared to the audio source to audio output device direction. Therefore, in this use case, the link margin is limited based on the audio source to audio output device having the poorer link margin of the two directions. In comparison, for a voice call, bidirectional data (audio) flow is typically present. In both directions EDR2 packets can be used, so there is no additional advantage due to use of BR packets. This can result in the direction from the audio output device to the audio source having the poorer link margin of the two directions. In this use case, therefore, the link margin is limited based on the audio output device to audio source direction.

[0055] The way data is transmitted for different use types can vary for the same communication protocol. Therefore, the link margin can vary for voice calls compared to music playback for the same communication protocol. For example AT may be less than £>, such as by 10 dB or more (e.g., 10 dB to 20 dB). In some embodiments detailed herein, use type is not factored in to the decision of which communication protocol to use, such as detailed in relation to method 600 of FIG. 6. In other embodiments, use type can be used in the determination of the communication protocol in addition to regulatory domain.

[0056] Referring to voice calls, AT may be less than R (such as by between 3 dB and 5 dB), but L may be greater than Q (such as be 12.5 dB or, more generally, between 3 dB and 20 dB).

Therefore, one protocol results in a higher link margin for one communication direction, but a lower link margin for the other communication direction. The limiting factor that is used to determine which communication protocol is to be used is avoiding the lowest link margin regardless of the communication direction. For example, regardless of the link margin from the audio source to the output device, if communication cannot occur from the output device to the audio source, communication will fail. Referring to FIG. 5, due to /W being less than R, a higher link margin is present for communication from the audio output device to the audio source for Bluetooth LE than Bluetooth Classic in the ETSI regulatory domain. In this situation, however, Q is the lowest link margin value among L, M, Q, and R, therefore the use of Bluetooth LE for communication from the audio source to the output device is desired to be avoided. Accordingly, it is preferable that Bluetooth Classic be used for the ETSI domain since it results in a higher minimum link margin.

[0057] The actual link margin measurements as indicated by variables in Table 500 may not be stored by the device determining which communication protocol to use. Rather multiple domain mappings may be stored that indicate which communication protocol should be used. Table 1 indicates an example of a domain mapping that may be used when only location is used in the analysis.

Table 1 [0058] In this example, only two regulatory domains are indicated. However, multiple more regulatory domains may be present in other embodiments of the domain mapping. For example, an additional domain mapping may be present for Japan and/or China. Additionally, a domain mapping may be present for locations not covered by the other listed domain mappings, such as in the form of a default domain mapping.

[0059] Table 2 indicates an example of a domain mapping that may be used when location and use type is used in the analysis.

Table 2

[0060] In the example domain mapping of Table 2, the use type can result in the preferred communication protocol being varied within a regulatory domain based on the use type. As shown, three use types are exemplified. Other use types are possible. Further, one or more domain mappings may be present for locations and/or use types not covered by the listed categories. For gaming, Bluetooth LE may be generally preferable since it has lower latency and, due to the nature of gaming usually involving a user directly interacting with a display device (which would likely be the audio source device) by holding the display device in front of the user or otherwise having the audio source device directly in front of the user, attenuation can be less of an issue, such as due to the distance between the audio source and audio output device being relatively short, less crossbody attenuation, and/or fewer obstacles between the audio source and audio output device.

[0061] The domain mappings that are used to select the wireless communication technology to be used may be created by a vendor or manufacturer of the audio source device, the audio output device, or some other party. In some embodiments, domain mappings are specific to particular audio output devices or a specific pair of an audio output device with and audio source device. For example, a manufacturer may create one or more domain mappings specific to their own audio source devices and audio output devices. If such a specific source/output device pairing is not used, the wireless communication technology may not be varied.

[0062] Various methods can be performed using the arrangements detailed in relation to FIGS. 1 A-5. FIG. 6 illustrates an embodiment of a method 600 for improving wireless link margin. In method 600, only the applicable regulatory domain may be used to determine the wireless communication protocol (or wireless communication technology) used for transmitting audio data packets. Method 600 can be generally performed by an audio output device (e.g., one or a pair of earbuds, headphones, a wireless speaker, etc.) and an audio source device (e.g., smartphone, tablet computer, gaming device, computer, etc.), such as shown in FIGS. 1 A-4. Further, method 600 can be applied to the Bluetooth family of communication protocols. Specifically, method 600 can be used to select between using Bluetooth Classic (e.g., enhanced data rate 2, EDR2) or Bluetooth LE. Selection between additional or other short-range wireless technologies is also possible.

[0063] Prior to block 605 being performed, a pairing process can have been performed to pair the audio output device with the audio source device. In the example of Bluetooth, an exchange of capabilities can occur as part of this pairing process. During this exchange, it can be established that the audio output device and the audio source device are mutually capable of multiple wireless communication protocols, such as Bluetooth Classic and Bluetooth LE.

[0064] At block 605, the audio source device, can determine its location. The location of the audio source device can be determined on a country-basis or regional-basis. In order to determine location, the audio source device can analyze a region or country code received from a wireless local area network (e.g., a WiFi network) and/or a region or country code received from a cellular network. For example, if the audio source device is a smartphone, the smartphone may be connected with a cellular network that broadcasts a region or country code. In other embodiments, other ways of obtaining a location are also possible, such as based on global navigation satellite systems or user input.

[0065] At block 610, a domain mapping can be selected based on the determined location. Using the location information determined at block 610, a domain mapping can be selected. Domain mappings can be stored locally by the audio source device or can be remotely accessible. Table 1 shows an example of domain mappings that can be stored. In addition or in alternate to indicating the regulatory domain, location indications are stored in the domain mapping that indicate which communication technology is to be used. [0066] Domain mappings may be stored to the audio source at the time of manufacture or can be acquired via network-transmitted downloads or updates. For example, when a compatible set of earbuds is paired, the domain mappings may be acquired by the audio source device from the audio output device or from a remote server system via a network.

[0067] At block 615, based on the selected domain mapping, a communication protocol to be used is selected. For example, referring to Table 1, if the audio source device is located in the United States, Bluetooth LE may be used. However, if the audio source device is located in Europe, Bluetooth Classic may be used. At block 620, audio data, such as audio packets, are transmitted using the selected communication protocol. Transmissions at block 620 are performed in accordance with the regulations set by the governing regulatory agency, such as based on power spectral density.

[0068] At a future time, if the audio source device’s location changes such that it is covered by a different regulatory agency, method 600 can result in a different communication protocol being used. For example, according to the domain mappings of Table 1 in accordance with method 600, while in the United States, Bluetooth LE may be used; but while in Europe, Bluetooth Classic (e.g., EDR2) may be used.

[0069] In some embodiments, additional blocks may be performed and/or the use type of the audio communication in addition to the location be used to determine the wireless communication technology used. FIG. 7 illustrates an embodiment of a method 700 for improving wireless link margin. Method 700 can be generally performed by an audio output device (e.g., one or a pair of earbuds, headphones, a wireless speaker, etc.) and an audio source device (e.g., smartphone, tablet computer, gaming device, computer, etc.), such as shown in FIGS. 1 A-4. Further, method 700 can be applied to the Bluetooth family of communication protocols. Specifically, method 700 can be used to select between using Bluetooth Classic (e.g., enhanced data rate 2, EDR2) or Bluetooth LE. Selection between additional or other short-range wireless technologies is also possible.

[0070] At block 705, a pairing process can have been performed to pair the audio output device with the audio source device. In the example of Bluetooth, an exchange of capabilities can occur as part of this pairing process. During this exchange, it can be established that the audio output device and the audio source device are mutually capable of multiple wireless communication protocols, such as Bluetooth Classic and Bluetooth LE.

[0071] At block 710, a determination may be made as to whether a domain mapping is available for the devices paired at block 705. For example, only certain audio output devices and audio source device pairings may be eligible to use an available or stored domain mapping. For example, a manufacturer or vendor may provide domain mappings that are only to be used when the audio source device and audio output device are both from the manufacturer or are only specific models from the manufacturer. If no domain mappings are applicable for the paired audio source device and audio output device, method 700 can proceed to block 740 where a default communication protocol is used. For example, the default communication protocol can be Bluetooth LE, even if both the audio source device and audio output device are capable of Bluetooth Classic communications. At block 740, the default communication protocol would be used regardless of regulatory domain and use type. It should be understood that blocks 705, 710, and 740 may also be performed as part of method 600.

[0072] If domain mappings are available for the pair of the audio source device and audio output device, method 700 can proceed to block 715. At block 715, the audio source device, can determine its location. The location of the audio source device can be determined on a countrybasis or regional -basis. In order to determine location, the audio source device can analyze a region or country code received from a wireless local area network (e.g., a WiFi network) and/or a region or country code received from a cellular network. For example, if the audio source device is a smartphone, the smartphone may be connected with a cellular network that broadcasts a region or country code. In other embodiments, other ways of obtaining a location are also possible, such as based on global navigation satellite systems or user input.

[0073] At block 720, a use type of the audio that is to be output can be determined. The use can be based on the application being executed on the audio source device that is outputting the audio. For example, a music streaming application that is outputting audio can be classified as having a “music” use type. As another example, if an application is used to make phone calls or conduct video conferencing, the use type could be classified as “voice.” As a third example, a game being the executed application can be used to determine a use type of “gaming.” A mapping may be stored that maps applications to use types. In other embodiments, packet inspection (e.g., the audio quality, whether the audio is two-way, etc.) may be performed to determine the use type of audio being output.

[0074] At block 725, a domain mapping can be selected based on the determined location and the determined use type. Using the location information determined at block 715 and the use type of block 720, a domain mapping can be selected. Domain mappings can be stored locally by the audio source device or can be remotely accessible. Table 2 shows an example of domain mappings that can be stored that factors in both regulatory domain (location) and use type. [0075] Domain mappings may be stored to the audio source at the time of manufacture or can be acquired via network-transmitted downloads or updates. For example, when a compatible set of earbuds is paired, the domain mappings may be acquired by the audio source device from the audio output device or from a remote server system via a network.

[0076] At block 730, based on the selected domain mapping, a communication protocol to be used is selected. For example, referring to Table 2, if the audio source device is located in the United States and the use type is music, Bluetooth LE may be used. However, if the audio source device is located in Europe for music, Bluetooth Classic may be used. If the use type was instead gaming, Bluetooth LE may be used in both locations, but if the use type was instead voice, Bluetooth Classic may be used in both locations.

[0077] At block 735, audio data, such as audio packets, are transmitted using the selected communication protocol of block 730. Transmissions at block 735 are performed in accordance with the regulations set by the governing regulatory agency, such as based on power spectral density.

[0078] It should be noted that the methods, systems, and devices discussed above are intended merely to be examples. It must be stressed that various embodiments may omit, substitute, or add various procedures or components as appropriate. For instance, it should be appreciated that, in alternative embodiments, the methods may be performed in an order different from that described, and that various steps may be added, omitted, or combined. Also, features described with respect to certain embodiments may be combined in various other embodiments. Different aspects and elements of the embodiments may be combined in a similar manner. Also, it should be emphasized that technology evolves and, thus, many of the elements are examples and should not be interpreted to limit the scope of the invention.

[0079] Specific details are given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, well-known, processes, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the embodiments. This description provides example embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the preceding description of the embodiments will provide those skilled in the art with an enabling description for implementing embodiments of the invention. Various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention. [0080] Also, it is noted that the embodiments may be described as a process which is depicted as a flow diagram or block diagram. Although each may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may have additional steps not included in the figure.

[0081] Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. For example, the above elements may merely be a component of a larger system, wherein other rules may take precedence over or otherwise modify the application of the invention. Also, a number of steps may be undertaken before, during, or after the above elements are considered. Accordingly, the above description should not be taken as limiting the scope of the invention.