Dual-transceiver wireless calling

Various implementations include dual-transceiver wireless audio systems configured to forward call audio from a first wireless transceiver to a second wireless transceiver over a simple voice forward profile (SVFP) connection. In other implementations, a computer-implemented method is disclosed for controlling a dual-transceiver wireless calling system. In still other implementations, a wireless headphone system is configured to forward call audio from a first headphone to a second headphone over the SVFP connection.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of U.S. patent application Ser. No. 15/928,250, filed on Mar. 22, 2018, the entire disclosure of which is incorporated herein by reference for all purposes.

TECHNICAL FIELD

This disclosure generally relates to wireless calling. More particularly, the disclosure relates to wireless audio systems, such as headphones or other wirelessly coupled audio systems having wireless transceivers, including a call audio forwarding module for controlling transmission of call audio and call control data between wireless transceivers.

BACKGROUND

Wireless electronic devices, including headphones and other wearable audio systems are becoming more commonplace. However, the user experience with these audio systems is limited by the inability of these systems to adapt to different environments and user experiences.

It has become commonplace to use devices employing point-to-point wireless communications technologies to create a personal area network in the vicinity of a user of personal electronic devices carried about by the user (referred to by some as a “piconet”) to convey audio from one of those personal electronic devices to one or both ears of the user, as in the case of the playback of audio stored on an audio playing device to the user. It has also become commonplace to additionally convey audio from the user to one of those personal electronic devices, as in the case of cell phone in which the user engages in telephonic communication through such point-to-point wireless communications with that device. Among the forms of such point-to-point wireless communications being used for such purposes are those that conform to the widely used “Bluetooth” specification promulgated by the Bluetooth Special Interest Group of Bellevue, Wash.

Wireless communications conforming to the Bluetooth specification have been in use for some time to wirelessly convey two-way audio between cell phones and so-called “earpieces” that incorporate both an acoustic driver to output call audio to an ear of a user and a microphone to receive call audio from the mouth of the user. More recently, there has been a growing emergence of audio playing devices employing wireless communications conforming to the Bluetooth specification to wirelessly convey one-way audio from those devices to one or more acoustic drivers to output audio to one or both ears of a user.

Unfortunately, despite the growing acceptance of such point-to-point wireless communications for the conveying of audio between personal electronic devices, the point-to-point nature, the procedures required to securely establish wireless connections, and the conversions of audio between various analog and digital forms have presented various difficulties. Those difficulties include various impediments to providing call audio to both ears of a user and sharing the call audio with another user.

SUMMARY

Various implementations include dual-transceiver wireless audio systems configured to forward call audio from a first wireless transceiver to a second wireless transceiver over a simple voice forward profile (SVFP) connection. In other implementations, a computer-implemented method is disclosed for controlling a dual-transceiver wireless calling system. In still other implementations, a wireless headphone system is configured to forward call audio from a first headphone to a second headphone over the SVFP connection.

In some particular aspects, a wireless audio system includes: a first wireless transceiver configured to establish a wireless link with an audio gateway for receiving and sending call audio and exchanging call control data; and a second wireless transceiver configured to wirelessly communicate with the first wireless transceiver over a simple voice forward profile (SVFP) connection, where the first wireless transceiver is configured to forward the call audio to the second wireless transceiver and exchange the call control data with the second wireless transceiver over the SVFP connection.

In other particular aspects, a computer-implemented method of controlling a wireless audio system having a first wireless transceiver, a second wireless transceiver and an audio gateway configured to send and receive call audio, and exchange call control data, over a wireless link between the first wireless transceiver and the audio gateway is disclosed. In these aspects, the method includes: establishing a simple voice forward profile (SVFP) connection between the first wireless transceiver and the second wireless transceiver; and forwarding, from the first wireless transceiver, the call audio received from the audio gateway to the second wireless transceiver over a synchronous connection-oriented (SCO) link established by the SVFP connection.

In additional particular aspects, a wireless headphone system includes: a first headphone having: at least one first microphone; and a first wireless transceiver connected with the at least one first microphone and configured to establish a wireless link with an audio gateway for receiving and sending call audio; and a second headphone having: at least one second microphone; and a second wireless transceiver connected with the at least one second microphone and configured to wirelessly communicate with the first wireless transceiver over a simple voice forward profile (SVFP) connection, where the first wireless transceiver is configured to forward the call audio to the second wireless transceiver over the SVFP connection.

In certain implementations, the SVFP connection includes a dedicated radio frequency communication (RFCOMM) channel and a dedicated synchronous connection-orientated (SCO) link between the first wireless transceiver and the second wireless transceiver. In some cases, the first wireless transceiver is configured to receive and send call audio over the SCO link and exchange the call control data over the RFCOMM channel established by the SVFP.

In particular instances, the wireless audio system further includes a headphone system having a first headphone containing the first wireless transceiver and a second headphone containing the second wireless transceiver. In certain implementations, the first headphone further includes at least one first microphone and the second headphone further includes at least one second microphone, where the second wireless transceiver is configured to send call audio received at the at least one second microphone to the first wireless transceiver over a synchronous connection-orientated (SCO) link established by the SVFP connection, and where the first wireless transceiver is configured to send the call audio received from the second wireless transceiver to the audio gateway over a synchronous connection-orientated (SCO) link established by a hands-free profile (HFP) connection. In some cases, the first headphone and the second headphone are configured to disable an on-ear detection operating mode during receipt or transmission of the call audio. In particular implementations, the SVFP connection permits the call audio and the call control data to travel exclusively over the SVFP connection between the first wireless transceiver and the second wireless transceiver, and the SVFP connection permits control of delay in playing the call audio by a digital signal processor (DSP) in at least one of the first headphone or the second headphone. In certain instances, the delay in playing the call audio by the DSP permits synchronization of playing the call audio by the DSP in the first headphone and the DSP in the second headphone.

In some implementations, the wireless audio system further includes an audio conference system paired with a headphone system, where the first wireless transceiver is contained in the audio conference system and the second wireless transceiver is contained in the headphone system.

In certain cases, the wireless link between the first wireless transceiver and the audio gateway, and a second wireless link between the first wireless transceiver and the second wireless transceiver, are over Bluetooth.

In particular instances, forwarding the call audio to the second wireless transceiver and exchanging the call control data with the second wireless transceiver over the SVFP connection does not involve a hands-free profile (HFP) connection between the first wireless transceiver and the second wireless transceiver.

In some implementations of a computer-implemented method, the SVFP connection is established in response to a hands-free profile (HFP) connection being established between the audio gateway and the first wireless transceiver, and the method further includes: exchanging the call control data between the first wireless transceiver and the second wireless transceiver over a radio frequency communication (RFCOMM) channel established by the SVFP connection.

In some cases, a service discovery protocol (SDP) server at the second wireless transceiver has a service record with generic audio as a major service class and simple voice forward as a minor service class, and specifies a custom universally unique identifier (UUID) on a service class identification (ID) list, forming a custom Bluetooth profile for the SVFP connection, and the SVFP connection is initiated by the first wireless transceiver by sending an SDP query to the second wireless transceiver with the custom UUID as a parameter, and upon receipt of the SDP query, the second wireless transceiver responds positively with an SDP response with a dedicated RFCOMM channel number as a parameter.

In certain instances, control of the delay in playing the call audio by the DSP includes exchanging delay information within call control data over a radio frequency communication (RFCOMM) channel established by the SVFP connection between the first wireless transceiver and the second wireless transceiver.

In particular implementations, the first headphone further includes a first digital signal processor (DSP) coupled with the first wireless transceiver and the second headphone further includes a second DSP coupled with the second wireless transceiver, and the first DSP and the second DSP are configured to synchronize playing the call audio at the first wireless transceiver and the second wireless transceiver by exchanging delay information as part of the call control data exchanged over the RFCOMM channel established by the SVFP connection.

Two or more features described in this disclosure, including those described in this summary section, may be combined to form implementations not specifically described herein.

It is noted that the drawings of the various implementations are not necessarily to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the implementations. In the drawings, like numbering represents like elements between the drawings.

DETAILED DESCRIPTION

This disclosure is based, at least in part, on the realization that a call audio forwarding module can be beneficially incorporated into a wireless audio system to provide for added functionality. For example, a wireless audio system can help to enable, among other things, call audio forwarding from a first wireless transceiver to a second wireless transceiver over a simple voice forward profile (SVFP) connection.

Commonly labeled components in the FIGURES are considered to be substantially equivalent components for the purposes of illustration, and redundant discussion of those components is omitted for clarity.

Aspects and implementations disclosed herein may be applicable to a wide variety of wireless audio systems, such as a portable speaker, headphones, and wearable audio devices in various form factors, such as glasses, neck-worn speakers, shoulder-worn speakers, body-worn speakers, etc. Unless specified otherwise, the term headphone, as used in this document, includes various types of personal audio systems such as around-the-ear, over-the-ear and in-ear headsets, earphones, earbuds, hearing aids, or other wireless-enabled audio devices structured to be positioned near, around or within one or both ears of a user. Unless specified otherwise, the term wearable audio device, as used in this document, includes headphones and various other types of personal audio devices such as shoulder or body-worn acoustic devices that include one or more acoustic drivers to produce sound without contacting the ears of a user. It should be noted that although specific implementations of personal audio devices primarily serving the purpose of acoustically outputting audio (e.g., call audio) are presented with some degree of detail, such presentations of specific implementations are intended to facilitate understanding through provision of examples, and should not be taken as limiting either the scope of disclosure or the scope of claim coverage.

Aspects and implementations disclosed herein may be applicable to personal audio devices that either do or do not support two-way communications, and either do or do not support active noise reduction (ANR). For personal audio devices that do support either two-way communications or ANR, it is intended that what is disclosed and claimed herein is applicable to a personal audio device incorporating one or more microphones disposed on a portion of the personal audio device that remains outside an ear when in use (e.g., feedforward microphones), on a portion that is inserted into a portion of an ear when in use (e.g., feedback microphones), or disposed on both of such portions. Still other implementations of personal audio devices to which what is disclosed and what is claimed herein is applicable will be apparent to those skilled in the art.

Example configurations of a wireless audio system include an audio gateway capable of making and receiving phone calls (e.g., a cellular phone, personal data assistant (PDA), tablet, personal computer (PC), wearable communication system, or any other known audio gateway for initiating and/or receiving phone calls). The audio gateway can be paired with a set of wireless transceivers, which can include wirelessly connected headphones, earbuds, wearable audio devices, audio conference system(s), smart speakers, etc. In the example of a headphone system such as a wireless earbud headphone system, the wireless transceivers are wirelessly linked with the audio gateway (and each other) in order to perform call-related functions (e.g., receive/send call audio).

As used herein, the term “call audio” refers to analog audio received on microphone(s), or digital form of the audio which is transferred in encoded format through the audio channel between the audio gateway and the first wireless transceiver or between the first wireless transceiver and the second wireless transceiver. As additionally used herein, the term “call control data” refers to data that is used to configure and control various parameters of the call functionality, which is transferred through the data channel between the audio gateway and the first wireless transceiver or between the first wireless transceiver and the second wireless transceiver.

In some wireless audio systems, call audio is not forwarded from the first wireless transceiver (or primary transceiver) to second or subsequent wireless transceivers (e.g., a second wireless transceiver). In these cases, the call audio is only played at the location of the first wireless transceiver (e.g., the first headphone or earbud). Some other wireless audio systems attempt to deliver call audio to the second wireless transceiver by performing so-called wireless “snooping,” where the second wireless transceiver establishes a secondary wireless link with the audio gateway to mirror transmission between the audio gateway and the first wireless transceiver.

Some other wireless audio systems make a hands-free profile (HFP) connection between the first wireless transceiver and the second wireless transceiver to transfer audio received on the first wireless transceiver from the audio gateway into the second wireless transceiver. However, this solution inhibits effective synchronization between the audio played at the first wireless transceiver and the second wireless transceiver because HFP does not inherently support synchronization.

In contrast to these systems, various implementations as described herein include a wireless audio system configured to forward call audio from a first wireless transceiver to a second wireless transceiver and exchange call control data with the second wireless transceiver over a customized simple voice forward profile (SVFP) connection.

FIG. 1is a block diagram of a wireless audio system10according to various implementations of the disclosure. The wireless audio system10includes an audio gateway20, a first speaker30and a second speaker40. The specific configuration of the audio gateway20and each of the speakers30and40can vary based upon the particular application of the various implementations disclosed, which may have any one of several forms. The audio gateway20may be implemented as any device capable of receiving a phone call, and can include one of a mobile phone, a portable game player, a portable media player, a smart speaker system, a computer (e.g., PC or tablet), an audio/video (A/V) receiver as part of a home entertainment or home theater system, etc.

The speakers30and40can take the form of any wireless speaker system, including, e.g., a headphone system or an audio conference system. In some cases, as described herein, speakers30and40can be part of distinct wireless speaker systems, such as where first speaker30is contained in a wireless headphone system and second speaker40is contained in an audio conference system. In other particular implementations, speakers30and40are part of a single wireless speaker system, such as a pair of wireless earbuds. In any case, speakers30,40can each include a conventional speaker housing, e.g., a stand-alone speaker casing, headphone casing, earbud casing, or can be housed within a larger component such as a computer or A/V receiver, and can include any type of conventional electro-acoustic transducers. Speaker30may be a left channel speaker and speaker40may be a right channel speaker, or vice-versa, in which either speaker may be configured for either stereo channel.

The audio gateway20, and speakers30,40each have a wireless transceiver for sending and receiving wireless communications. In particular implementations, each wireless transceiver (comprising a transmitter and a receiver) can include, for example, a Bluetooth (BT) or Bluetooth Low Energy (BLE) transceiver or other conventional transceiver device, and may be configured to communicate with other transceiver devices as described herein. The audio gateway20can include a gateway (wireless) transceiver50, first speaker30can include a first (wireless) transceiver60and second speaker40can include a second (wireless) transceiver70.

In some implementations, each of the speakers30,40can further include at least one microphone (first microphone(s)80, second microphone(s)90) for receiving call audio from a user and/or performing noise reduction functions as described herein. In various implementations, such as in the case of a headphone system, the microphone(s)80,90can include one or more internal microphones (inner microphones) disposed within a cavity for surrounding the user's ear. In some cases, the microphone(s)80,90can further include an outer microphone disposed in a manner that permits acoustic coupling to the environment external to the speaker30,40.

In implementations that include active noise reduction (ANR), the inner microphone may be a feedback microphone and the outer microphone may be a feedforward microphone. In such implementations, each earphone speaker30,40includes an ANR circuit that is in communication with the inner and outer microphones. The ANR circuit can receive an inner signal generated by the inner microphone and an outer signal generated by the outer microphone, and perform an ANR process for the corresponding speaker30,40. The process includes providing a signal to electroacoustic transducers (e.g., speakers)100,110disposed in the cavity around the ear to generate an anti-noise acoustic signal that reduces or substantially prevents sound from one or more acoustic noise sources that are external to the speaker30,40from being heard by the user. As described herein, in addition to providing an anti-noise acoustic signal, the electroacoustic transducers100,110can utilize its sound-radiating surface for providing an audio output for playback, e.g., for providing call audio at both of the speakers30,40.

According to some implementations, each of the speakers30,40can further include a control circuit (first control circuit120, second control circuit130) including a microcontroller or processor having a digital signal processor (DSP). The respective control circuits120,130can communicate with transceivers60,70and microphone(s)80,90, as well as with the electroacoustic transducers100,110to control the audio output to the user. In certain examples, the control circuits120,130can convert inner signals from the inner microphones and/or the outer signals from outer microphones to digital format by analog to digital converters. In response to the received inner and/or outer microphone signals, the control circuit(s)120,130can take various actions. For example, audio playback may be initiated, paused or resumed, a notification to a wearer may be provided or altered, and a device in communication with the wireless audio system10may be controlled.

The wireless audio system10can also include a power source. In some cases, the control circuit120,130and power source may be located in one or both of the speakers30,40or may be in a separate housing in communication with the speakers30,40. As noted herein, the speakers30,40can communicate with the audio gateway20and/or other devices via wireless transceivers60,70, which may be contained within a network interface (e.g., employing a wireless communication protocol such as IEEE 802.11, Bluetooth, Bluetooth Low Energy, or other local area network (LAN) or personal area network (PAN) protocols such as WiFi). In particular implementations, as noted herein, wireless transceivers60,70are particularly suited to communicate with the wireless transceiver50at audio gateway20via Bluetooth.

In operation, streamed data can pass from the network interface (e.g., wireless transceivers60,70) to the control circuit(s)120,130, including the processor or microcontroller. The control circuit(s)120,130can execute instructions (e.g., for performing, among other things, digital signal processing, decoding, and equalization functions), including instructions stored in a corresponding memory (which may be internal to control circuit(s)120,130or accessible via the network interface or other network connection (e.g., cloud-based connection)). The control circuit(s)120,130may be implemented as a chipset of chips that include separate and multiple analog and digital processors. The control circuit(s)120,130may provide, for example, for coordination of other components of the wireless audio system10, such as control of user interfaces (not shown) and applications run by the wireless audio system10. In various implementations, control circuit(s)120,130include a call audio forwarding module (or modules), which can include software and/or hardware for performing call forwarding processes described herein. For example, control circuit(s)120,130can include a call audio forwarding module in the form of a software stack having instructions for controlling call audio functions, connection functions and audio functions according to any implementation described herein.

In addition to a processor and/or microcontroller, control circuit(s)120,130can also include one or more digital-to-analog (D/A) converters for converting the digital audio signal to an analog audio signal. This audio hardware can also include one or more amplifiers which provide amplified analog audio signals to the electroacoustic transducer(s)100,110, which each include a sound-radiating surface for providing an audio output for playback. In addition, the audio hardware may include analog-to-digital (A/D) circuitry for processing analog input signals to provide digital audio signals for sharing with other devices.

The memory in control circuit(s)120,130can include, for example, flash memory and/or non-volatile random access memory (NVRAM). In some implementations, instructions (e.g., software) are stored in an information carrier. The instructions, when executed by one or more processing devices (e.g., the processor or microcontroller in control circuit(s)120,130), perform one or more processes, such as those described elsewhere herein. The instructions can also be stored by one or more storage devices, such as one or more (e.g. non-transitory) computer- or machine-readable mediums (for example, the memory, or memory on the processor/microcontroller). As described herein, the control circuit(s)120,130(e.g., memory, or memory on the processor/microcontroller) can include a control module including instructions for controlling call audio forwarding functions according to various particular implementations. It is understood that portions of the control module (e.g., instructions) could also be stored in a remote location or in a distributed location, and could be fetched or otherwise obtained by the control circuit(s)120,130(e.g., via any communications protocol described herein) for execution. The instructions may include instructions for controlling call audio forwarding functions (i.e., the software modules include logic for processing inputs audio gateway20, first speaker30and second speaker40), as well as digital signal processing and equalization. Additional details may be found in U.S. Patent Application Publication 20140277644, U.S. Patent Application Publication 20170098466, and U.S. Patent Application Publication 20140277639, the disclosures of which are incorporated herein by reference in their entirety.

In operation, wireless audio system10is configured to control forwarding of call audio from first transceiver60to second transceiver70over a simple voice forward profile (SVFP) connection140. In various particular implementations, wireless audio system10is configured to initiate the SVFP connection140between the first transceiver60and the second transceiver70in response to a hands-free profile (HFP) connection150being established between the audio gateway20and the first transceiver60. As described herein, after the SVFP connection140is established between the first transceiver60and the second transceiver70, the first transceiver60is configured to forward the call audio to the second transceiver70as well as exchange call control data with the second wireless transceiver70over the SVFP connection140.

FIG. 2is a flow diagram200illustrating processes in forming HFP connection150between the audio gateway (AG)20(gateway transceiver50) and the first transceiver (FT)60(FIG. 1) over Bluetooth. As described herein, this HFP connection150can be a pre-requisite to establishing the SVFP connection140, such that control circuit120is configured to initiate the SVFP connection140after successfully completing the HFP connection150between the audio gateway20and the first speaker30. Generally, this conventional HFP connection150is formed by a number of processes. For example, a service level connection202between the audio gateway20and the first transceiver60is established. Next, an internal event or user action204can trigger a codec connection setup206between the audio gateway20and the first transceiver60. Finally, after the codec connection setup206, audio connection208is established between the audio gateway20and the first transceiver60. The audio connection208permits audio paths between audio gateway20and first transceiver60, as is known in the art. Additional details of establishing a conventional HFP connection can be found in Hands-Free Profile Specification version 1.7, which is hereby incorporated by reference in its entirety.

As noted herein, the HFP connection150is a pre-requisite for SVFP connection140(FIG. 1) in various implementations.FIG. 3is a flow diagram300illustrating some processes in forming the SVFP connection140between the first transceiver60and the second transceiver70(FIG. 1), after successfully establishing HFP connection150. As with the HFP connection150between audio gateway20and first transceiver60, the SVFP connection140between first transceiver60and the second transceiver70can be made over Bluetooth. Processes in establishing the SVFP connection140can include establishing both an SVFP service level connection and an SVFP audio connection. In various implementations, these processes are performed sequentially.

According to some implementations, the SVFP connection140is initiated by the first transceiver60and accepted by the second transceiver70. This SVFP connection140allows the initiator of the SVFP service level connection to act as the acceptor of the SVFP audio connection, and vice versa. Further, the acceptor of one of the SVFP connections can terminate that connection. It is understood that the SVFP connection could also be initiated by the second transceiver70, and accepted by the first transceiver60, according to various other implementations.

In various implementations, the SVFP service level connection establishes an RFCOMM channel between the first transceiver60and the second transceiver70. A pre-requisite for this connection is that the transceivers60,70should be connected at a link manager (LM) link level. This connection may be established by exchanging Link Manager Protocol (LMP) commands between the first transceiver60and the second transceiver70. Processes performed in establishing the SVFP service level connection, and illustrated in flow diagram300ofFIG. 3, can include:

Process302: an internal event occurs at the first transceiver60, initiating the service level connection process. In some cases, this internal event can be the establishment of an HFP service level connection between the audio gateway20and the first transceiver60.

Process304: first transceiver60sends an SDP search request (query) to the second transceiver70to determine whether that second transceiver70is an SVFP audio device.

Process306: The second transceiver70responds affirmatively, indicating an ability to connect over an RFCOMM channel, and identifying the second transceiver70as an SVFP audio device.

Process308: first transceiver60sends an RFCOMM connection request to second transceiver70.

Process310: second transceiver70sends an affirmative RFCOMM connection response, resulting in an RFCOMM connection.

Process312: first transceiver60sends a Bluetooth request support features (BRSF) request to determine which Bluetooth features are supported by second transceiver70. This BRSF (Bluetooth Retrieve Supported Features) request can be transmitted over the established RFCOMM connection.

Process314: second transceiver70sends AT command response to the AT command request, indicating BRSF supported features to first transceiver60, and the SVFP service level connection is established. This BRSF AT command response can be transmitted over the established RFCOMM connection.

In various implementations, second transceiver70includes a service discovery protocol (SDP) server with a service record. The service record can indicate generic audio as a major service class and simple voice forward or similar unique name as a minor service class. Additionally, this service record can specify a custom universally unique identifier (UUID) on a service class identification (ID) list, forming the basis for a custom Bluetooth profile for the SVFP connection.

In some particular cases, the SVFP connection is initiated by the second transceiver70. In these cases, the second transceiver70sends an SDP query to the first transceiver60with the custom UUID as a parameter, and upon receipt of the SDP query, the first transceiver60responds positively with an SDP response with a dedicated RFCOMM channel number as a parameter.

FIG. 4is a flow diagram400illustrating processes in releasing the SVFP service level connection established by processes in flow diagram300(FIG. 3), according to various implementations. This process can include:

Process402: an internal event occurs at the second transceiver70, initiating the service level release process. In some cases, this internal event can be the release of HFP service level connection between the first transceiver60and the second transceiver70.

Process404: the first transceiver60sends an RFCOMM disconnect request to the second transceiver70.

Process406: the second transceiver70sends an RFCOMM disconnect response to the first transceiver60, and the SVFP service level connection is released.

While illustrated as first transceiver60initiating the release, it is understood that the service level connection release may be initiated by either of the transceivers60,70, e.g., where there is an internal condition at the respective transceiver60,70driving that release, such as release of HFP service level connection between the audio gateway20and the first transceiver60, upon which the first transceiver60initiates a service level disconnection, or second transceiver70has a higher priority service to be carried out that demands the service level connection to be terminated, upon which the second transceiver70initiates the service level disconnection.

FIG. 5is a flow diagram500illustrating processes in forming the SVFP audio connection between the first transceiver60and the second transceiver70. As noted herein, the processes illustrated inFIG. 5can necessarily follow the SVFP service level connection illustrated in the flow diagram300ofFIG. 3, such that the service level connection is a pre-requisite for the audio connection. The SVFP audio connection between transceivers60,70involves sharing codec information, loading a codec plugin (if required), and establishment of a dedicated synchronous connection-orientated (SCO) link (or extended synchronous connection-oriented (eSCO) link) to carry encoded audio packets. The SVFP audio connection can be initiated by either transceiver60,70, however, the example ofFIG. 5shows the first transceiver60as initiator. As shown, SVFP audio connection processes can include:

Process502: an internal event occurs at the first transceiver60, initiating the SVFP audio connection process. In some cases, this internal event can be the establishment of HFP audio connection between the audio gateway20and the first transceiver60.

Process504: first transceiver60sends an AT command request BCS (Bluetooth Codec Selection) to the second transceiver70.

Process506: second transceiver70sends a confirmation (OK) indicating it received the AT command from first transceiver60and the required codec is supported.

Process508: the SCO link between transceivers60,70is established, resulting in an audio connection between those transceivers.

As with the service level connection, the audio connection between transceivers60,70can also be released according to a sequence. Release of this audio connection can be performed by either transceiver60,70, however, the example process shown in flow diagram600inFIG. 6is initiated by the first transceiver60. This process can include:

Process602: an internal event occurs at the first transceiver60, initiating the audio connection release process. This internal event can be the release of audio connection between the audio gateway20and the first transceiver60.

Process604: the first transceiver60sends an SCO link disconnect request to the second transceiver70.

Process606: the second transceiver70sends an SCO link disconnect response, releasing the audio connection.

Returning toFIG. 1, when the SVFP connection140(including both service level and audio connection) is established between the first transceiver60and the second transceiver70, the first transceiver60is configured to forward the call audio to the second transceiver70, as well as exchange call control data between the transceivers60,70over that SVFP connection140. As noted herein, in some implementations, this SVFP connection140includes a dedicated RFCOMM channel and a dedicated SCO link between the transceivers60,70.

Additionally, the HFP connection150between the first transceiver60and the audio gateway20permits the first transceiver60to exchange call audio and call control data with the audio gateway20over an SCO link. However, according to various embodiments, forwarding the call audio to the second wireless transceiver70and exchanging the call control data with the second wireless transceiver70over the SVFP connection140does not involve a hands free profile (HFP) connection (e.g., HFP connection150) between the first wireless transceiver60and the second wireless transceiver70. As opposed to utilizing a conventional HFP connection between the transceivers60,70, this SVFP connection140is customized for audio forward functionality and hence it does not consume as many resources as an HFP connection would. Moreover, the SVFP profile is customizable, and has a mechanism for synchronization of playing of audio in first speaker30and second speaker40, which is not inherently provided by the HFP profile.

With continuing reference toFIG. 1, as noted herein, the wireless audio system10includes a headphone system in some particular implementations. In these cases, at least one of the speakers30,40can include headphones, which can include wireless headphones such as earbuds or wireless on-ear, over-ear or otherwise wearable headphones. It is also possible that the speakers30,40in these implementations can include any other personal audio device described herein. In particular implementations, each of the speakers30,40can include one or more microphones80,90for receiving call audio from the user. In some cases, second speaker40(with second transceiver70and second microphone(s)90) is configured to receive call audio from the user and send that call audio to the first speaker30(with first transceiver60) over the SCO link established by the SVFP connection140. First speaker30(with first transceiver60) is configured to then send that call audio from the second speaker40to the audio gateway20over the SCO link established by the HFP connection150.

In various particular implementations, the speakers30,40are configured to be physically separated and utilized by distinct users or groups of users. That is, where speakers30,40include earbuds or other headphones, one of the speakers30,40could be removed from the user and transferred to another user, e.g., for call sharing. In this case, each of the speakers30,40can independently receive call audio from the same or distinct users. In one example scenario, distinct users can discretely participate on a conference call, such that one user can both send and receive call audio at the first speaker30and another user can both send and receive call audio at the second speaker40. In this case, the speakers30,40can include additional sensors for detecting an operating mode of the speaker30,40. For example, the speakers30,40can include sensors coupled with the control circuit130for performing on-ear detection (as well as head tracking), to determine whether an earbud or other headphone is on the user's ear. The on-ear detection mechanism can include any conventional on-ear detection approach, utilizing one or more sensors such as a motion detector, gyroscope, accelerometer, etc. In certain cases, the control circuit120,130is configured to disable the on-ear detection operating mode of the speaker30,40during receipt or transmission of the call audio. This control mechanism can allow a user to share the call audio experience with another user, e.g., by sharing a speaker with that user without interruption from the on-ear detection mechanism.

As noted herein, the SVFP connection140between the first transceiver60and the second transceiver70permits call audio and call control data to travel exclusively over that connection between the transceivers60,70. This SVFP connection140can also permit control of delay in playing the call audio by the DSP (in control circuits120,130) in one or both speakers30,40. Delay control can include exchanging delay information within call control data over the RFCOMM channel established by the SVFP connection140between the first transceiver60and the second transceiver70. This delay control permits synchronization in playing the call audio at the respective speakers30,40. Controlling this delay and synchronization in call audio between speakers30,40can provide benefits relative to conventional speaker connections, because if the speakers are connected over a conventional HFP connection instead of SVFP connection, the HFP connection does not provide an inherent mechanism to synchronize the playing of voice on the speakers.

FIG. 7is an example data flow diagram700illustrating data paths at the first speaker30(primary speaker) relative to the audio gateway20and second speaker40in wireless audio system10after establishment of the SVFP connection140. As shown, the first speaker30receives incoming SCO packets from the audio gateway20over the SCO link established by the HFP connection150. Firmware704at the first speaker30streams the encoded SCO packets to the IN port of the DSP706(in control circuit120). As noted herein, in contrast to other systems, wireless audio system10is configured to forward audio from first speaker30to second speaker40. That is, as shown inFIG. 7, prior to decoding the SCO packets received at the IN port, the DSP706routes those (raw, un-decoded) SCO packets to its RELAY OUT port back to the firmware704, where the raw SCO packets are sent to the second speaker40over the SCO link established by the SVFP connection140. Additionally, the raw SCO packets received at the IN port of the DSP706are decoded and converted (digital-to-analog conversion) to provide analog audio to the transducer at the first speaker30, as controlled by the control circuit120(FIG. 1).

Analog audio received at the microphone(s)80is also processed at the first speaker30. As shown, this analog audio is converted (analog-to-digital conversion) and encoded as controlled by the control circuit120(FIG. 1). The encoding is done by the DSP706, and then the firmware704fetches the encoded SCO packets, where it is sent to the audio gateway20over the SCO link established by the HFP connection150.

FIG. 8is an example data flow diagram800illustrating data paths in playing audio at the second speaker40(secondary speaker) relative to the first speaker30, as a continuation ofFIG. 7. It is understood that this data flow diagram does not illustrate sending call audio back to first speaker40, however, as noted herein, various implementations can include sending call audio received at second speaker40back to audio gateway20via first speaker30. That is, the data flow diagrams inFIGS. 7 and 8are intended to depict only the single-microphone example configuration of wireless audio system10. It is understood that second speaker40could receive and process call audio from its microphone(s)90in a manner similar to first speaker30, e.g., as shown inFIG. 7.

Returning toFIG. 8, as shown, second speaker40receives incoming SCO packets from the first speaker30over the SCO link established by the SVFP connection140. Firmware802at the second speaker40streams the encoded SCO packets to the IN port of the DSP804(in control circuit130). Additionally, the raw SCO packets received at the IN port of the DSP804are decoded and converted (digital-to-analog conversion) to provide analog audio to the transducer at the second speaker40, as controlled by the control circuit120(FIG. 1).

As described herein, the wireless audio system10is configured to forward call audio from a first wireless transceiver to a second wireless transceiver and exchange call control data with the second wireless transceiver over a simple voice forward profile (SVFP) connection. This SVFP connection can provide mechanisms for effective delay control, synchronization, and customization of connections between the transceivers when compared with conventional approaches.

The functionality described herein, or portions thereof, and its various modifications (hereinafter “the functions”) can be implemented, at least in part, via a computer program product, e.g., a computer program tangibly embodied in an information carrier, such as one or more non-transitory machine-readable media, for execution by, or to control the operation of, one or more data processing apparatus, e.g., a programmable processor, a computer, multiple computers, and/or programmable logic components.

Actions associated with implementing all or part of the functions can be performed by one or more programmable processors executing one or more computer programs to perform the functions of the calibration process. All or part of the functions can be implemented as, special purpose logic circuitry, e.g., an FPGA and/or an ASIC (application-specific integrated circuit). Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. Components of a computer include a processor for executing instructions and one or more memory devices for storing instructions and data.

In various implementations, unless otherwise noted, electronic components described as being “coupled” can be linked via conventional hard-wired and/or wireless means such that these electronic components can communicate data with one another. Additionally, sub-components within a given component can be considered to be linked via conventional pathways, which may not necessarily be illustrated.