System and method for synchronizing audio content

Abstract

The invention relates to a system and method for synchronizing audio content. The method includes establishing, by a primary earplug of a pair of earplugs, a first connection with a device, the primary earplug receiving audio data from the device via the first connection. The method includes establishing a bridge connection between the primary earplug and a shadow earplug, the shadow earplug receiving the audio data and link characteristics via the bridge connection to establish a shadow connection with the device to receive the audio data from the device. The method includes maintaining, by the shadow earplug, a timing relationship between the bridge connection and the shadow connection. The method includes detecting, by the shadow earplug, a failure of reception on the shadow connection. The method includes synchronizing, by the shadow earplug, a timing window using the timing relationship to communicate with the device within the timing window.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to systems and methods of communicating between audio devices, such as a pair of Bluetooth earbuds. BACKGROUND

[0002] The market for wireless communication devices has grown several orders of magnitude over the past few decades due to the use of portable devices and the increase in connectivity and data communication between a wide variety of devices. Improvements in digital and radio frequency (RF) circuit fabrication, as well as integration of circuits and other advances, have made wireless devices smaller, cheaper, and more reliable. However, these wireless devices can be limited by limited battery power and intermittent connectivity due to environmental conditions or obstructions. Managing the link state between devices immediately after connectivity is interrupted can impact battery life, as the devices either in vain enable a radio or enter a sleep state for an extended window of time and thus miss data transmissions. SUMMARY

[0003] A pair of earbuds can connect with a source device for audio data, such as a mobile phone. For example, a first earbud of the pair of earbuds can connect with the phone via a first link, while a second earbud of the pair of earbuds can monitor the first link. The first link is sometimes referred to as a master link without limitation, and the earbud that connects with the phone is sometimes referred to as a master earbud without limitation. The second earbud is sometimes referred to as a shadow earbud, and the signal path of the master link monitored by the shadow earbud is sometimes referred to as a shadow link. The first earbud and the second earbud can connect with each other via a further link, referred to as a bridge connection. For example, the shadow earbud can receive audio data or link characteristics via the bridge connection. Thereafter, the shadow earbud can monitor air packets transmitted from the mobile phone to the master earbud using the link characteristics received via the bridge connection.

[0004] When the shadow earbud successfully receives a packet on the shadow connection, the shadow earbud can synchronize with the phone. In particular, if the shadow earbud receives a packet from the phone, the shadow earbud can update the timing of its anchor point on the shadow connection. However, in the absence of receiving audio data, the shadow earbud can adjust its receive time (extend the receive window, RX window) to allow for uncertainty in the transmission timing of the phone. The shadow earbud can maintain a timer that is reset upon receiving a valid packet. The timer is sometimes referred to as a policing timer that enforces a policing timeout value. When the timer reaches the policing timeout value, the shadow earbud can determine that the connection has been lost.

[0005] In certain user scenarios, the signal quality of the shadow connection is poor, while the signal quality of the bridge connection is good. For example, when a user wearing two earbuds walks away from the phone, the primary earbud can maintain a connection with the phone, while the shadow earbud disposed across a physical barrier can compromise the integrity of the shadow link. In this scenario, the shadow earbud can miss data transmitted via the shadow connection, which can result in the following drawbacks. First, power consumption can increase with RX window adjustment. When the shadow earbud fails to reliably receive data from the phone over the shadow link, the shadow earbud can expand the RX window on the shadow connection. However, these power-consuming attempts are futile because the shadow earbud is outside the communication range of the phone. Additionally, if the shadow connection is disconnected, the software stack can repeatedly attempt to reestablish the connection unsuccessfully, which also increases power consumption. Second, the shadow earbud can expand its RX window until the shadow earbud receives data from another device (e.g., the primary earbud), at which point the shadow earbud can synchronize with the other device (e.g., the primary earbud). The shadow earbud can synchronize with the primary earbud such that the shadow earbud cannot recover the shadow connection. Third, when the shadow earbud moves back within the communication range of the phone, a delay occurs before audio is restored while the shadow connection is reestablished.

[0006] According to the present disclosure, a mechanism is provided for the shadow earbud to maintain synchronization to the phone's clock over the bridge connection when the signal quality of the shadow connection is poor. The shadow earbud maintains a timing relationship between the bridge connection and the shadow connection. When the shadow earbud synchronizes to the primary earbud over the bridge connection, the shadow earbud is also able to use this timing relationship to synchronize its clock to the phone's clock. Even when the shadow earbud receives unsuccessfully over the shadow connection, the shadow earbud can be considered synchronized to the phone as long as the primary connection and the bridge connection remain connected. In some embodiments, the shadow earbud resets the policing timer only upon receiving a valid packet over the shadow connection. In some embodiments, the shadow earbud resets the policing timer upon receiving a valid packet over the shadow connection or over the bridge connection. Thus, the policing timer can be extended when the bridge connection is connected.

[0007] According to these techniques, power consumption can be reduced relative to other approaches. For example, the RX window on the shadow connection can remain small and accurate as if its clock was synchronized in the last connection event of the bridge connection. This reduces power consumption compared to the case where the shadow earpiece relies only on reception from the shadow connection to update its clock. Additionally, since the shadow connection is maintained even when signal quality is poor, the software stack does not enter a repeating loop of shadow connection creation failures. Furthermore, the small receive window on the shadow earpiece avoids synchronization to an incorrect device. When the shadow earpiece is out of range of the phone, and if the master earpiece is able to relay audio to the shadow earpiece, audio quality will be maintained even when the shadow earpiece is unable to receive audio from the phone over the shadow link. When the shadow earpiece moves back into range, the shadow earpiece will start receiving data from the phone over the shadow connection. The source of the audio (either relayed by the master earpiece over the bridge connection or received from the phone via the shadow connection) can be performed transparently to the end user without interruption or delay to the user experience.

[0008] Additionally, according to some embodiments of the disclosure, a user can listen to audio from both earpieces even when one of the two earpieces is unable to receive audio from the phone, which can provide a seamless audio playback to the user. For example, the policing timer can be ignored or continue to tick as soon as audio data is received via the bridge connection. In some embodiments of the disclosure, the policing timer can be enforced for the shadow connection. Although in some cases, when the shadow earpiece is waiting for reestablishment of the shadow connection (if the earpiece is out of range of the phone), the seamless user experience can be degraded immediately after expiration of the policing timer, such an embodiment can extend the battery life of a pair of earpieces. Furthermore, in some embodiments, the policing timer can be enforced for both the shadow connection and the bridge connection (e.g., the logical OR of the shadow connection and the bridge connection). Thus, expiration of the policing timer can correspond to a situation where the shadow earpiece has no audio data available, such that expiration of the policing timer does not actually interrupt any audio data. BRIEF DESCRIPTION OF DRAWINGS

[0009] The various objects, aspects, features and advantages of the present disclosure will become more fully understood and appreciated by reference to the detailed description, taken in conjunction with the accompanying drawings in which like reference characters identify corresponding elements throughout the several views. In the drawings, like reference numbers indicate similar or functionally similar elements.

[0010] Figure 1A is a block diagram depicting a network environment including one or more access points in communication with one or more devices or stations, in accordance with some embodiments;

[0011] Figure 1B and 1CThis is a block diagram depicting a computing device useful in conjunction with the methods and systems described herein, according to some embodiments;

[0012] Figure 2 It is a network diagram of an environment comprising a pair of audio devices coupled to a source audio device, according to some embodiments;

[0013] Figure 3 It is a timing slot diagram including a variable receive window according to some embodiments;

[0014] Figure 4 It is a sequence diagram for synchronizing audio content according to some embodiments; and

[0015] Figure 5 This is a flowchart of a method according to some embodiments.

[0016] Details of various embodiments of the method and system are set forth in the accompanying drawings and the following description. Detailed Implementation

[0017] The following disclosure provides numerous different embodiments or examples for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to simplify this disclosure. These are, of course, merely examples and are not intended to be limiting. For example, in the following description, a first feature communicating with or communicatively coupled to a second feature may include embodiments in which the first feature directly communicates with or is directly coupled to the second feature, and may also include embodiments in which an additional feature may be inserted between the first and second features such that the first feature indirectly communicates with or is indirectly coupled to the second feature. Additionally, reference numerals and / or letters may be repeated in various examples. Such repetition is for simplicity and clarity and is not inherently indicative of a relationship between the various embodiments and / or configurations discussed.

[0018] In some embodiments, the technology described herein relates to a method comprising: establishing a first connection with a device by a primary earbud of a pair of earbuds, the primary earbud receiving audio data from the device via the first connection; establishing a bridging connection between the primary earbud and a shadow earbud, the shadow earbud receiving the audio data and link characteristics via the bridging connection to establish a shadow connection with the device to receive the audio data from the device; maintaining a timing relationship between the bridging connection and the shadow connection by the shadow earbud; detecting a failure of reception on the shadow connection by the shadow earbud; and using the timing relationship to synchronize a timing window to communicate with the device within the timing window.

[0019] In some embodiments, the technology described herein relates to a method that further includes: detecting the recovery of the audio data by the shadow earpiece after the received failure; and adjusting the timing relationship by the shadow earpiece to resynchronize with the device.

[0020] In some embodiments, the technology described herein relates to a method that further includes: detecting an indication of the status of the first connection via the bridging connection by the shadow earbud after the failure to receive the audio data and before the recovery of the audio data; and in response to the detection of the indication, extending a timer by the shadow earbud during the timer period during which the shadow earbud receives the audio data via the shadow connection to maintain an active state.

[0021] In some embodiments, the technology described herein relates to a method that further includes: transmitting the indication from the main earbud to the shadow earbud, the indication comprising the audio data.

[0022] In some embodiments, the technology described herein relates to a method that further includes: detecting the audio data via at least one of the shadow connection or the bridging connection; and in response to the detection of the audio data, extending a timer during which the shadow earbud receives the audio data via the shadow connection to maintain an active state.

[0023] In some embodiments, the techniques described herein relate to a method that further includes transitioning to an inactive state in response to the expiration of a timer for at least one of the shadow connection or the bridging connection.

[0024] In some embodiments, the technology described herein relates to a method in which the shadow earbud is configured to: receive credentials from the main earbud via the bridging connection; and use the credentials to establish the shadow connection.

[0025] In some embodiments, the technology described herein relates to a method in which the first connection is a first Bluetooth link between the device and the main earbud; and the bridging connection is a second Bluetooth link between the main earbud and the shadow earbud.

[0026] In some embodiments, the techniques described herein relate to a method in which the second Bluetooth link is a lower power connection than the first Bluetooth link.

[0027] In some embodiments, the technology described herein relates to a method that further comprises: between the pair of earplugs: identifying a first earplug of the pair of earplugs as the master earplug; and identifying a second earplug of the pair of earplugs as the shadow earplug.

[0028] In some aspects, the technology described herein relates to a system comprising: a main earpiece configured to establish a first connection with a device, the first connection being configured to: transmit audio data from the device to the main earpiece; and establish a bridging connection with a shadow device, the bridging connection being configured to: transmit link characteristics including a timing window for the first connection; and a shadow earpiece configured to: detect a failure to receive the audio data during the same timing window; maintain the timing window for the shadow connection to receive the audio data, at least based on an indication of the status of the first connection received via the bridging connection; and use the same timing window to receive subsequent audio data.

[0029] In some embodiments, the technology described herein relates to a system in which the shadow earbud is configured to: extend a timer in response to detecting a first packet of a plurality of packets carrying audio data via the shadow connection, during which the shadow earbud will receive the audio data via the shadow connection to maintain an active state; detect the expiration of the timer if no further or subsequent packets are detected; and transition to a lower power state or mode in response to the expiration of the timer.

[0030] In some embodiments, the technology described herein relates to a system in which the shadow earbud is configured to extend the timer in response to detecting a second packet of the plurality of packets via the bridging connection.

[0031] In some embodiments, the technology described herein relates to a system in which the shadow earbud is configured to adjust the timing window based on data received via the bridging connection.

[0032] In some embodiments, the technology described herein relates to a system in which the data received via the bridging connection comprises packets containing a portion of the audio data.

[0033] In some embodiments, the technology described herein relates to a system in which the first connection is a first Bluetooth link between the device and the main earbud; and the bridging connection is a second Bluetooth link between the main earbud and the shadow earbud, wherein the second Bluetooth link is a lower power connection than the first Bluetooth link.

[0034] In some embodiments, the technology described herein relates to an apparatus comprising: an audio output device configured to negotiate one of a plurality of roles with a second audio output device, the plurality of roles corresponding to a main mode and a shadow mode between the audio output device and the second audio output device; during the main mode, establishing a first connection with an audio source device configured to deliver audio data from the audio source device to the audio output device; and establishing a bridged connection with the second audio output device configured to pass link characteristics for the first connection; and during the shadow mode, monitoring the first connection via the shadow connection using the link characteristics to detect a timing window for the audio data; detecting a failure to receive the audio data on the shadow connection during the timing window; and in response to receiving a packet containing the audio data via the bridged connection, extending a timer during which the audio output device will receive the audio data via the shadow connection to maintain an active state.

[0035] In some embodiments, the technology described herein relates to an apparatus further configured to extend the timer in the shadow mode in response to receiving a packet containing the audio data via the shadow connection.

[0036] In some embodiments, the technology described herein relates to an apparatus further configured to: during the main mode, transmit the audio data received via the first connection to the second audio output device via the bridging connection; and during the shadow mode, if the audio data is not received during the timing window, transition to an inactive state in response to the expiration of the timer.

[0037] In some embodiments, the technology described herein relates to an apparatus in which: the first connection is a first Bluetooth link between the audio source device and the audio output device; and the bridging connection is a second Bluetooth link between the audio output device and the second audio output device, wherein the second Bluetooth link is a lower power connection than the first Bluetooth link.

[0038] The following descriptions and corresponding contents of the various sections of this specification may be helpful in reading the descriptions of the various embodiments described below:

[0039] Section A describes the network and computing environments that can be used to practice the embodiments described herein; and

[0040] Section B describes embodiments of the access protocol and the methods and apparatus for using the access protocol.

[0041] A. Computing and Network Environment

[0042] Before discussing specific embodiments of this solution, it may be helpful to describe aspects of the operating environment and associated system components (e.g., hardware elements) in conjunction with the methods and systems described herein. References Figure 1A This describes an embodiment of a network environment. In simple terms, the network environment includes a wireless communication system comprising one or more access points (APs) or network devices 106, one or more stations or wireless communication devices 102, and network hardware components or network hardware 192. For example, wireless communication device 102 may include a laptop computer, tablet computer, personal computer, and / or cellular phone device. (See reference...) Figure 1B and 1C More detailed descriptions are provided for embodiments of each station or wireless communication device 102 and AP or network device 106. In one embodiment, the network environment may be a temporary network environment, an infrastructure wireless network environment, a subnet environment, etc. Network device 106 or AP may be operatively coupled to network hardware 192 via a local area network (LAN) connection. In some embodiments, network device 106 is a 5G base station. Network hardware 192, which may include routers, gateways, switches, bridges, modems, system controllers, devices, etc., may provide LAN connectivity for communication systems. Each of network device 106 or AP may have an associated antenna or antenna array to communicate with wireless communication devices in its area. Wireless communication device 102 may register with a specific network device 106 or AP to receive services from a communication system (e.g., via SU-MIMO or MU-MIMO configuration). For direct connections (e.g., point-to-point communication), some wireless communication devices may communicate directly via an assigned channel and communication protocol. Some of wireless communication devices 102 may be mobile or relatively static relative to network device 106 or AP.

[0043] In some embodiments, network device 106 or AP includes means or modules (combining hardware and software) that allow wireless communication device 102 to connect to a wired network using Wireless Fidelity (WiFi) or other standards. Network device 106 or AP may sometimes be referred to as a Wireless Access Point (WAP). Network device 106 or AP may be implemented (e.g., configured, designed, and / or built) to operate in a Wireless Local Area Network (WLAN). In some embodiments, network device 106 or AP may be connected as a standalone device to a router (e.g., via a wired network). In other embodiments, network device 106 or AP may be a component of a router. Network device 106 or AP may provide network access to multiple devices. For example, network device 106 or AP may connect to a wired Ethernet connection and use a radio frequency link to provide wireless connectivity for other devices 102 to utilize that wired connection. Network device 106 or AP may be implemented to support standards for transmitting and receiving data using one or more radio frequencies. These standards and the frequencies they use may be defined by IEEE (e.g., the IEEE 802.11 standard). Network device 106 or AP may be configured and / or used to support public Internet hotspots and / or extend the Wi-Fi signal range of a network over a network.

[0044] In some embodiments, the access point or network device 106 may be used for (e.g., home, vehicle, or building) wireless networks (e.g., IEEE 802.11, Bluetooth, ZigBee, any other type of radio frequency-based network protocol, and / or variations thereof). Each of the wireless communication devices 102 may include a built-in radio and / or be coupled to a radio. Such wireless communication devices 102 and / or access point or network device 106 may operate according to various aspects of the present disclosure as presented herein to enhance performance, reduce cost and / or decrease size, and / or enhance broadband applications. Each wireless communication device 102 may have the capability to act as a client node that seeks access to resources (e.g., data and connections to networked nodes (e.g., servers)) via one or more access points or network devices 106.

[0045] The network connection may include any type and / or form of network, and may include any of the following: point-to-point network, broadcast network, telecommunications network, data communication network, computer network. The network topology may be a bus network topology, a star network topology, or a ring network topology. The network may be any such network topology known to those skilled in the art as capable of supporting the operations described herein. In some embodiments, different types of data may be transmitted via different protocols. In other embodiments, the same type of data may be transmitted via different protocols.

[0046] The communication device 102 and the access point or network device 106 can be deployed as any type and form of computing device and / or executed on any type and form of computing device, such as a computer, network device or equipment capable of communicating and performing the operations described herein on any type and form of network. Figure 1B and 1C A block diagram depicting a computing device 100 for implementing embodiments of wireless communication device 102 or network device 106. (See diagram for reference.) Figure 1B and 1C As shown, each computing device 100 includes a processor 121 (e.g., a central processing unit) and a main memory unit 122. Figure 1B As shown, the computing device 100 may include a storage device 128, a mounting device 116, a network interface 118, an I / O controller 123, display devices 124a to 124n, a keyboard 126, and a pointing device 127 (e.g., a mouse). The storage device 128 may include an operating system and / or software. Figure 1C As shown, each computing device 100 may also include additional optional elements that communicate with the central processing unit or processor 121, such as memory port 103, bridge 170, one or more input / output devices 130a to 130n, and cache memory 140.

[0047] The central processing unit or processor 121 is any logic circuit system that responds to and processes instructions fetched from main memory unit 122. In many embodiments, the central processing unit or processor 121 is provided by a microprocessor unit, such as a microprocessor unit manufactured by Intel Corporation of Santa Clara, California; a microprocessor unit manufactured by International Business Machines of White Plains, New York; or a microprocessor unit manufactured by Advanced Micro Devices of Sunnyvale, California. The computing device 100 may be based on any of these processors or any other processor capable of operating as described herein.

[0048] Main memory unit 122 may be one or more memory chips capable of storing data and allowing direct access to any storage location by a microprocessor or processor 121, such as any type or variant of static random access memory (SRAM), dynamic random access memory (DRAM), ferroelectric RAM (FRAM), NAND flash, NOR flash, and solid-state drive (SSD). Main memory unit 122 may be based on any of the memory chips described above or any other available memory chip capable of operating as described herein. Figure 1B In the embodiment shown, the processor 121 communicates with the main memory unit 122 via the system bus 150 (described in more detail below). Figure 1C An embodiment of a computing device 100 is depicted, wherein the processor communicates directly with the main memory unit 122 via a memory port 103. For example, in Figure 1C In this context, the main memory unit 122 can be DRDRAM.

[0049] Figure 1C This illustration depicts an embodiment in which the main processor 121 communicates directly with the cache memory 140 via a secondary bus (sometimes also referred to as a back-side bus). In other embodiments, the main processor 121 communicates with the cache memory 140 using a system bus 150. The cache memory 140 typically has a faster response time than the main memory unit 122 and is provided by, for example, SRAM, BSRAM, or EDRAM. Figure 1C In the embodiments shown, processor 121 communicates with various I / O devices 130 via local system bus 150. Various buses can be used to connect the central processing unit or processor 121 to any of the I / O devices 130, such as VESA VL bus, ISA bus, EISA bus, Microchannel Architecture (MCA) bus, PCI bus, PCI-X bus, PCI-Express bus, or NuBus. In embodiments where the I / O device is a video display 124, processor 121 may communicate with display 124 using an Advanced Graphics Port (AGP). Figure 1C An embodiment of a computer or computer system 100 in which the main processor 121 can communicate directly with the I / O device 130b, for example, via HYPERTRANSPORT, RAPIDIO, or INFINIBAND communication technologies is described. Figure 1C An embodiment in which local bus and direct communication are mixed is also depicted: processor 121 communicates with I / O device 130a using local interconnect bus, while simultaneously communicating directly with I / O device 130b.

[0050] The computing device 100 may contain various I / O devices 130a to 130n. Input devices include keyboards, mice, tracking pads, trackballs, microphones, dial pads, touchpads, touchscreens, and graphics tablets. Output devices include video displays, speakers, inkjet printers, laser printers, projectors, and dye-to-sublimation printers. Figure 1B As shown, the I / O devices can be controlled by I / O controller 123. The I / O controller can control one or more I / O devices, such as keyboard 126 and pointing device 127 (e.g., mouse or optical pen). Furthermore, the I / O devices can also provide storage and / or mounting media for computing device 100. In other embodiments, computing device 100 may provide USB connectivity (not shown) to receive handheld USB storage devices, such as the USB flash drive series devices manufactured by Twintech Industry, Inc. of Los Alamitos, California.

[0051] Refer again Figure 1B The computing device 100 may support any suitable installation device 116, such as a disk drive, CD-ROM drive, CD-R / RW drive, DVD-ROM drive, flash memory drive, tape drive of various formats, USB device, hard disk drive, network interface, or any other device suitable for installing software and programs. The computing device 100 may further include a storage device, such as one or more hard disk drives or a redundant array of independent disks, for storing an operating system and other related software and for storing application software programs, such as any program or software 120 for implementing (e.g., configured and / or designed for) the systems and methods described herein. Optionally, any of the installation devices 116 may also be used as a storage device. Additionally, the operating system and software may run from bootable media.

[0052] Furthermore, the computing device 100 may include a network interface 118 that interfaces with a network via various connections, including but not limited to standard telephone lines, LAN or WAN links (e.g., 802.11, T1, T3, 56kb, X.25, SNA, DECNET), broadband connections (e.g., ISDN, Frame Relay, ATM, Gigabit Ethernet, Ethernet over SONET), wireless connections, or any or a combination of the above. Connections can be established using various communication protocols (e.g., TCP / IP, IPX, SPX, NetBIOS, Ethernet, ARCNET, SONET, SDH, Fiber Distributed Data Interface (FDDI), RS232, IEEE 802.11, IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE 802.11ac, IEEE 802.11ad, CDMA, GSM, WiMax, and Direct Asynchronous Connection). In one embodiment, computing device 100 communicates with other computing devices 100' via any type and / or form of gateway or tunneling protocol (e.g., Secure Slot Layer (SSL) or Transport Layer Security (TLS)). Network interface 118 may include a built-in network adapter, network interface card, PCMCIA network card, card bus network adapter, wireless network adapter, USB network adapter, modem, or any other device suitable for interfacing computing device 100 to any type of network capable of communicating and performing the operations described herein.

[0053] In some embodiments, computing device 100 may include or be connected to one or more display devices 124a to 124n. Thus, any of the I / O devices 130a to 130n and / or I / O controller 123 may include any type and / or form of suitable hardware, software, or a combination of hardware and software to support, enable, or provide computing device 100 with connectivity to and use of display devices 124a to 124n. For example, computing device 100 may include any type and / or form of video adapter, video card, driver, and / or library to interface with, communicate with, connect to, or otherwise use display devices 124a to 124n. In one embodiment, a video adapter may include multiple connectors to interface with display devices 124a to 124n. In other embodiments, computing device 100 may include multiple video adapters, each connected to display devices 124a to 124n. In some embodiments, any portion of the operating system of computing device 100 may be configured to use multiple display devices 124a to 124n. In other embodiments, I / O device 130 may be a bridge between system bus 150 and external communication bus, such as USB bus, Apple desktop bus, RS-232 serial connection, SCSI bus, FireWire bus, FireWire 800 bus, Ethernet bus, AppleTalk bus, Gigabit Ethernet bus, asynchronous transfer mode bus, Fibre Channel bus, fiber optic bus, serial Attached Small Computer System Interface bus, USB connection, or HDMI bus.

[0054] Figure 1B and 1CThe computing device 100 described herein can operate under the control of an operating system that controls task scheduling and access to system resources. The computing device 100 can run any operating system, such as any of the following: various versions of Microsoft Windows, different releases of Unix and Linux, any version of MAC OS for Macintosh computers, any embedded operating system, any real-time operating system, any open-source operating system, any proprietary operating system, any operating system for mobile computing devices, or any other operating system capable of running on a computing device and performing the operations described herein. Typical operating systems include, but are not limited to: Android, manufactured by Google; Windows 7, 8, and 10, manufactured by Microsoft Corporation of Redmond, Washington; MAC OS, manufactured by Apple Computer of Cupertino, California; WebOS, manufactured by Research In Motion (RIM); OS / 2, manufactured by International Business Machines of Armonk, New York; and Linux, a freely available operating system, or any type and / or form of Unix operating system, released by Caldera Corp. of Salt Lake City, Utah, as well as other operating systems.

[0055] The computer system or computing device 100 can be any workstation, telephone, desktop computer, laptop or notebook computer, server, handheld computer, mobile phone or other portable telecommunications device, media playback device, gaming system, mobile computing device, or any other type and / or form of computing device, telecommunications device or media device capable of communication. In some embodiments, the computing device 100 may have a different processor, operating system, and input device consistent with the device described herein. For example, in one embodiment, the computing device 100 is a smartphone, mobile device, tablet computer, or personal digital assistant. Furthermore, the computing device 100 can be any workstation, desktop computer, laptop or notebook computer, server, handheld computer, mobile phone, any other computer, or other form of computing device or telecommunications device capable of communication and having sufficient processor power and memory capacity to perform the operations described herein.

[0056] In the context of the systems and methods disclosed herein, the various aspects of the operating environment and components described above will become apparent.

[0057] B. Synchronized Audio Content

[0058] This document discloses a system and method for synchronizing audio content between a mobile phone or other audio source device and a receiving device, such as a pair of earpieces. The receiving device may include a master device and a shadow device that can be predetermined (e.g., hard-coded) or arbitrated therebetween. The master receiving device may establish a first connection with the audio source device and receive audio data (e.g., packetized audio data) from the audio source device. The master receiving device may establish a bridging connection with the shadow receiving device to provide link characteristic data with the shadow receiving device. The shadow receiving device may use the link characteristic data to establish a shadow connection (monitoring audio data exchanged over the connection between the source device and the receiving device). However, in some cases, the shadow connection may be compromised; in some cases, this compromise may correspond to the continuous supply of audio data from the audio source device to the receiving device via the first connection.

[0059] Maintaining a shadow connection during substantial impairment (e.g., decoding packet failure) can inhibit future operation. For example, a shadow receiver may increase its RX window, during which the transceiver is active to attempt to resolve timing skew. In some cases, the widened RX window may eventually include time slots from other devices (e.g., the primary receiver). If the shadow receiver synchronizes to such a transmission, it may not detect further audio data even if it is in range (because the transmission window narrows immediately after synchronization as a power-saving measure to reduce transceiver activity). Even without such resynchronization, the widened RX window may unnecessarily deplete the shadow receiver's battery. Therefore, the shadow receiver may instantiate a timer that is extended (e.g., reset) immediately after receiving a status update on the first link between the audio source device and the primary receiver. In some embodiments, the indication includes receiving audio data via the shadow connection. In some embodiments, the indication is provided in response to a transmission within the original RX window. In some embodiments, the indication is received via a bridging connection. For example, the indication may include a flag indicating the status of the connection, etc., indicating the transmission of audio data from the main receiving device (e.g., an indication that audio data from the shadow receiving device has failed to be transmitted to the main receiving device), a flag indicating the status of the connection, etc.

[0060] refer to Figure 2According to some embodiments, a network diagram 200 is provided comprising an environment including a pair of audio devices 202 coupled to an audio source device 216. The pair of audio devices 202 may comprise any of various audio devices, such as an illustrative example of a first device for a shadow earbud 202A and a second device for a main earbud 202B. This illustrative example should not be construed as limiting; the systems and methods provided herein can be used with wireless speakers, hearing aids, VR / AR headsets, etc. As mentioned throughout this disclosure, the illustrative example of the earbud may be replaced by various other devices.

[0061] A pair of earbuds 202 may refer to or include two wireless earbuds designed or configured to work together to provide audio from received audio data via a speaker. For example, the pair of earbuds may split the audio data into a left channel and a right channel. The pair of earbuds may include a master earbud 202B and a shadow earbud 202A that can be dynamically arbitrated or predefined. The master earbud 202B may refer to or include an earbud that actively establishes a connection with a device providing audio content. For example, the master earbud 202B may include a Bluetooth peripheral. The shadow earbud 202A may refer to or include a second earbud in the pair that relies on the master earbud 202B to connect to the audio source, for example by providing a link characteristic between the master earbud 202B and the device, or by providing the audio data itself.

[0062] Audio data may refer to or contain digital information representing the audio waves generated for output to a speaker-transducer (e.g., an audio driver for an earphone pair). For example, audio data may be transmitted as packets, frames, or other streams. Audio data can be transmitted via any of the various connections described herein. Various references to audio data do not necessarily refer to bit-by-bit copies of the same data. For example, audio data may be reconstructed (e.g., re-grouped, provided according to different formats, manipulated to remove right or left channel audio, etc.).

[0063] A connection refers to any type and form of link established between at least two devices. The connection can be established using any type or form of protocol (e.g., Wi-Fi or Bluetooth). For example, a connection established between the main earbud and another device can refer to or include a connection configured to transmit data (e.g., audio data) between an audio source device and the earbud (e.g., the main earbud).

[0064] Link characteristics refer to any type of characteristic or attribute of a connection or link, such as a connection or link between two devices (e.g., earbud 202). Link characteristics may refer to, identify, or contain information related to the operation, performance, authentication, authorization, or security of the connection. For example, link characteristics may include various credentials, device identifiers, pairing information, profiles, frequency hopping sequences, communication channels, or slot timings. Credentials may contain link keys, decryption keys, or other tokens that can be used to derive data from packets or streams (e.g., deriving audio data from Bluetooth packets). Such link characteristics can be used to encode and / or decode data.

[0065] Each of the shadow earbud 202A and the main earbud 202B can receive audio data from the audio source device 216 (e.g., a depicted example of a mobile phone). For example, the main earbud 202B can negotiate a first connection 201 (e.g., a Bluetooth link) between the audio source device 216 and the main earbud 202B. The shadow earbud 202A can monitor the first connection 201 via a non-targeted receiver path (referred to as shadow connection 203). For example, the shadow earbud 202A can receive audio data via shadow connection 203, such that each of the shadow earbud 202A and the main earbud 202B can provide audio to a user. In some embodiments, the shadow earbud 202A can monitor the first connection 201 using link information received through a bridging connection 205 between the pair of earbuds 202. The link information may include a Bluetooth device address, clock offset, frequency hopping mode, or session parameters such as link type or audio codec for the audio source device 216 or the main earbud 202B. In some embodiments, the link information includes security credentials, such as a link key for the first connection 201, an access code (e.g., a channel access code), or other authentication or decryption data.

[0066] A shadow connection can refer to or encompass a path between an audio source device and another device (e.g., a shadow earbud). For example, a shadow connection can be established by a shadow earbud decoding information from a wireless medium using link characteristic data. A bridged connection can refer to or encompass a communication channel established between a main earbud and a shadow earbud. For example, a bridged connection can be used to transmit audio data or link characteristics between earbuds.

[0067] In some embodiments, a Bluetooth link may refer to or include a connection established between devices using the Bluetooth protocol. Each link may be established using one or more configuration settings. For example, some audio streaming links may be established using a Bluetooth Classic connection (e.g., a connection using an Advanced Audio Distribution Profile (A2DP)), while other links may be established using other connections such as a Bluetooth Low Energy (BLE) link (e.g., a 2 Mbps PHY link (LE2M) connection).

[0068] As depicted, the environment surrounding the pair of audio devices 202 and audio source device 216 may include various obstacles 220, such as walls, equipment, or people (e.g., the head of a user wearing earbuds 202). Furthermore, even in the absence of obstacles 220, variations in signal path length or antenna orientation can modulate the received signal strength based on changes between the first connection 201 and the shadow connection 203. In some cases, the shadow connection 203 may become compromised, while the bridging connection 205 and the first connection 201 are active. In such cases, the main earbud 202B may provide an indication of the received audio data to the shadow earbud 202A, which may be provided by the main earbud 202B indicating the transmission of the audio data itself or by providing a flag or other indication of the reception of the audio data. This indication may include any adjustment to the RX window such that the shadow earbud 202A continues to monitor the window, or the shadow earbud 202A may be configured to assume no drift.

[0069] The main earbud 202B can establish a bridging connection 205 with the shadow earbud 202A (which can be negotiated or instantiated by either the main earbud 202B or the shadow earbud 202A). The main earbud 202B can provide link information to the shadow earbud 202A via the bridging connection 205, and the shadow earbud 202A can use the link information to monitor the first connection 201 (this may be referred to as establishing a shadow connection 203). In some embodiments, the main earbud 202B can provide audio data to the shadow earbud 202A. The audio data provided to the shadow earbud 202A may contain the same audio data received by the main earbud 202B via the first connection 201, or it may be different from the audio data. For example, the main earbud 202B may compress the audio data to provide to the shadow earbud 202A, or transmit a subgroup of audio data (e.g., left channel data or right channel data). For example, this compression can facilitate the retransmission of audio data, where the bridging connection 205 is provided as a lower power or lower throughput link relative to the first connection 201. In some embodiments, the main earbud 202B can retransmit audio data in response to an indication that no audio data has been received (e.g., an indication provided by the shadow earbud 202A via the bridging connection 205). This technique reduces the power consumption of the main earbud 202B, thereby avoiding the retransmission of audio data when the shadow connection 203 is active, such as from the shadow earbud 202A to the main earbud 202B. In some cases, the main earbud 202B can provide further indications (e.g., to indicate that no audio data has been received, such as indicating a loss of communication with the audio source device 216).

[0070] In some embodiments, the roles of the shadow earbud 202A and the main earbud 202B can be arbitrated between the respective devices. Therefore, the shadow earbud 202A and the main earbud 202B are depicted as having consistent components. In some embodiments, the shadow earbud 202A and the main earbud 202B can be predefined, such as in the case of the left and right earbuds, allowing certain functions to be omitted or modified between the earbuds 202. However, as provided herein, components will be collectively referred to as role-agnostic pairs that can be arbitrated to act as either the shadow earbud 202A or the main earbud 202B.

[0071] Each of the earpieces includes a speaker 204 (depicted as speaker 204A and speaker 204B), which may be implemented according to various transducers to output audio data. The speaker output may correspond to data packets containing audio data received by transceiver 206. For example, in some embodiments, each packet may contain tens of milliseconds of data for the speaker.

[0072] Each of the earbuds 202 includes at least one transceiver 206 (depicted as transceiver 206A and transceiver 206B). The transceiver 206 includes an antenna, amplifier, buffer, or other components configured to transmit (send or receive) information via a transmission medium. For example, in some embodiments, the transceiver 206 may be implemented as a Bluetooth transceiver 206, a Wi-Fi transceiver 206, or other wireless transceivers. In some embodiments, the same transceiver 206 may communicate via multiple communication links. In some embodiments, a single transceiver 206 may be dedicated to a single link. For example, the transceiver 206 used for bridging connection 205 and the first connection 201 or shadow connection 203 may be implemented with separate physical antennas, amplifiers, buffers, etc. In some embodiments, the same transceiver 206 may communicate through multiple channels according to a time schedule, examples of which are described below. Figure 3 supply.

[0073] Each of the earpieces 202 includes a timing component 208 (depicted as timer / synchronizer 208A and timer / synchronizer 208B). The timing component 208 may include a synchronizer to synchronize a communication window (e.g., an RX window or a TX window) with data availability. For example, the synchronizer may update the RX window to center on the received data to compensate for any drift between devices. Recentering may refer to centering the beginning, end, or other portion of the received data within the RX window. For example, recentering may align the beginning of the received data with the first ten percent of the RX window, such that the received packets can fit within the RX window for the maximum or other expected packet size.

[0074] According to some embodiments, a timer may refer to or include a mechanism for tracking time periods, time intervals, or elapsed time, such as actions that can be used to trigger, for example, resynchronization or transition to an inactive state. For example, a monitoring timer may continue to count during a period when it is not communicating with another device, such that after the timer reaches a target value, the device can take further action. For example, such further action may include stopping operation to conserve battery power or resizing the RX window. In some embodiments, a timer may be extended (e.g., reset) based on one or more criteria. For example, a monitoring timer may be extended in response to detecting activity on at least one of a bridging connection or a shadow connection (e.g., receiving audio data). In some embodiments, a timeout period may refer to or include a time interval maintained by the timer (e.g., resetting or otherwise extending the timer). In some embodiments, transitioning to an inactive state may refer to or include disabling one or more power-consuming components of the device. For example, transition may refer to causing a transceiver, such as a Bluetooth transceiver, to stop operating, enter a sleep state, standby mode, or cease all operation.

[0075] In response to no data being detected, the synchronizer can extend the RX window, which can help receive data if the time drift exceeds the limits of the RX window. However, extending the RX window also increases power usage associated with the total active time of transceiver 206. The synchronizer can be configured to maintain a timing relationship including the RX window size immediately after receiving an indication of connection status. For example, the main earpiece 202B can provide an indication that audio data has been received (e.g., by retransmitting audio data), indicating that the audio data was transmitted within the receive window, and that extending the receive window does not solve potential communication problems.

[0076] A connection status can refer to, identify, or include the state or condition of a connection's operation or performance. A connection status can refer to, identify, or include an indication of signal strength or connection quality, whether the connection is active, inactive, or idle. A connection status can refer to, identify, or include the status of a timer or window for receiving or transmitting data. For example, a status indication can include an indication of the activity of the connection, such as the time elapsed since a previously detected packet, or the content of those packets. The indication can include discrete indications (e.g., flags indicating an active or open connection) or can be inferred from further markings. For example, the retransmission of audio data via a bridged connection can indicate the activity status of a connection from which audio data was previously received. For example, a shadow earbud can infer that a first connection between the main earbud and another device is operational and active based on audio data received via a bridged connection.

[0077] Timing component 208 may include a monitoring timer to monitor link timeouts. For example, if the device does not receive a packet via the link within a predetermined time period (e.g., five seconds), the monitoring timer may provide a flag or other indication to power manager 210, causing earpiece 202 to enter an indication state. Earpiece 202 may be configured to reset or extend the timer after receiving valid data via the connection, or in response to other indications of link status (e.g., an activity indication via first connection 201 received via bridge connection 205).

[0078] Each of the earbuds 202 includes power management circuitry 210 (depicted as power manager 210A and power manager 210B). Power management circuitry 210 enables the earbuds to transition between various states in which one or more components or functions are inactive (generally referred to as inactive states). For example, inactive states may include powering down the display, transceiver 206, processor 121, speaker 204, or other components. For example, in response to the expiration of a regulatory timer, power management circuitry 210 may enter a low-power inactive state to conserve battery power or otherwise reduce energy usage.

[0079] Each of the earbuds may include an authenticator 212 (depicted as authenticator 212A and authenticator 212B). Authenticator 212 may generate or store credentials, such as a device identifier, a pre-configured device security key, a link key unique to a pair (e.g., a pair to establish the first connection 201), or other session keys. Authenticator 212B of the main earbud may be configured to transmit credentials to the shadow earbud 202A via bridging connection 205. Authenticator 212A of the shadow earbud may be configured to receive credentials from the main earbud 202B to monitor the first connection 201 (e.g., to establish a shadow connection 203).

[0080] Each of the earbuds may include an arbitrator 214 (depicted as arbitrator 214A and arbitrator 214B). The arbitrator 214 may negotiate roles with other arbitrator instances. For example, in some instances, the first earbud powered on may broadcast an arbitration message and act as a leader if no response is received, and as a follower (indicating that another device is active) if a response is received. In some embodiments, an earbud may be initially encoded to act as a leader by default, but may switch to a follower role upon receiving a response or no response from another device. According to other embodiments, the arbitrator 214 may function according to further technologies, such as token passing, looping, polling, etc., or may arbitrate with yet another device, such as a smart charging case for earbud 202, a mobile phone coupled to earbud 202, etc.

[0081] In some embodiments, arbitration may refer to or include a process of managing or resolving roles or responsibilities among multiple devices (e.g., determining roles in a leader / follower pattern). For example, in some embodiments, a pair of earbuds may determine a master earbud and a shadow earbud based on arbitration, such that either earbud can assume either role, contrary to embodiments where one earbud (e.g., the right earbud) is pre-designated as the master earbud. For example, a first earbud that establishes a connection with another device (e.g., an audio source device, such as a mobile phone) may assume the role of leader and communicate with a second earbud to designate its role as follower.

[0082] For reference Figure 3 According to some embodiments, a timing slot diagram 300 including a variable receive window is provided. The depicted timing slot diagram 300 includes a timeline 301 for an environment including a pair of earbuds 202 and an audio source device 216. More specifically, the timeline 301 includes an RX window 302 for a shadow earbud 202A, which may correspond to a shadow connection 203. That is, the shadow earbud 202A can be configured to activate a transceiver during the RX window 302 to receive communication from the audio source device 216 to the main earbud 202B via the first connection 201 through the shadow connection 203. Upon detection of such communication, the shadow earbud 202A can immediately compensate for any drift of the audio data transmitter (audio source device 216) by recentering or otherwise synchronizing the RX window on the received data.

[0083] In addition to the RX window 302 of shadow connection 203, timeline 301 also includes additional time that can be dedicated to other devices, other functions, etc. For example, a second RX window 304 may correspond to the RX window of bridging connection 205, while a third window 306 may correspond to a communication link separate from shadow connection 203, such as an uplink from the main earbud 202B to the audio source device 216 (e.g., the RX window for the audio source device 216 and the TX window for the main earbud 202B, which can be used to provide volume control, pause commands, or other uplink communications). As depicted, like other periods of timeline 301, RX window 302 can be configured to repeat according to a regular period 308. Although the duration of period 308 can be shared between devices, the duration can be slightly adjusted to maintain synchronization between devices because timing parameters can drift over time. For example, if data arrives one clock tick (approximately 312 microseconds) ahead of time, subsequent periods 308A can be shortened accordingly to maintain synchronization.

[0084] A failure to receive audio data can refer to or include the absence of detected audio data for a period of time, such as one or more pre-scheduled transmission cycles of that audio data. For example, a failure to receive audio data can refer to the expiration of timers for one or more RX windows without receiving audio data, or the absence of audio data during one or more RX windows. Audio data recovery can refer to or include the detection of audio data after a reception failure has been detected.

[0085] Following a failure to detect audio data during one or more consecutive RX windows 302, the shadow earpiece 202A can be configured to extend the window. By extending the window, the shadow earpiece 202A can adjust the start or end time of the RX window 302. For example, after a first time period (which may correspond to a predetermined number of time periods 308, or at least a portion of a monitoring timer), the shadow earpiece 202A can extend the RX window 302 to the drawn delimiter of the first extension of the RX window 302A. After a second time period in which no data is received, the shadow earpiece 202A can extend the RX window 302A to the drawn delimiter of the second extension of the RX window 302B. The shadow earpiece 202A can continue to extend the RX window 302 until data is received or a timer (e.g., a monitoring timer) expires, causing the shadow earpiece 202A to transition to an inactive state.

[0086] In cases where RX window 302 is expanded due to timing drift, shadow earpiece 202A can immediately detect data after expanding RX window 302, resynchronizing RX window 302 with the data and reducing the window size, thus limiting the power usage of the expanded RX window 302 to a small number of instances (e.g., a first or second expansion of RX windows 302A, 302B). However, in cases where no data is received due to degraded shadow connection 203 (e.g., sub-threshold received signal strength), expanding RX window 302 does not substantially improve detection but increases power usage. In some cases, RX window 302 can be expanded until another window (e.g., a third window 306) is enclosed and resynchronized with that window. Therefore, even if the signal strength received via shadow connection 203 is improved, shadow earpiece 202A can have an inactive transceiver during the designated window 302, thereby synchronizing with the spurious data of the third window 306. Therefore, the instruction of the audio data received from the main earbud 202B via the first connection 201 can cause the shadow earbud 202A to maintain synchronization of the RX window 302 in order to reduce power usage relative to the extended RX window 302 and avoid synchronization with parasitic transmissions.

[0087] For reference Figure 4According to some embodiments, a sequence diagram 400 for synchronizing audio content is provided. Sequence diagram 400 may correspond to an environment including a main earbud 202B coupled to an audio source device 216 via a first connection 201. For example, the main earbud 202B may negotiate or otherwise establish the first connection 201 with the audio source device 216 to receive audio data from the audio source device 216 via the first connection 201. The establishment of the first connection 201 may include the generation or retrieval of link characteristics for the first connection 201, which may include credentials, timing windows, or other timing relationships, etc.

[0088] A timing relationship can refer to, identify, or include the temporal aspect of communication received or transmitted by two or more devices or connections, determined based on two or more devices or connections, or synchronized between two or more devices or connections. For example, a timing relationship can refer to the relationship between a first connection 201 and a bridging connection 205, wherein data transmitted via bridging connection 205 can be correlated with information previously received via the first connection 201. For example, audio data received via bridging connection 205 can prove that audio data was previously received via a timing window, which can correspond to the timing window of shadow earbud 202A. That is, according to the timing relationship, shadow earbud 202A can be determined to have transmitted audio data during the pending period of the timing window, even if shadow earbud 202A itself did not receive audio data.

[0089] In some embodiments, timing relationships can be determined locally based on received audio data. For example, the device receiving the audio data can align (e.g., recenter) the RX window with the data reception to avoid drift between devices (e.g., drift that may be caused by crystal aging, temperature changes, etc.). In some embodiments, resynchronization can refer to or include adjusting the timing relationships between connected devices. For example, as indicated above, a shadow earbud can align (e.g., recenter) the RX window to resynchronize with the audio source device.

[0090] At operation 402, the main earbud 202B transmits the link characteristics of the first connection 201 to the shadow earbud 202A. The link characteristics can be transmitted via a pre-existing bridging connection 205, or such a connection can be established simultaneously with the transmission of link characteristics. In some embodiments, the main earbud 202B may provide updates to various link characteristics to the shadow earbud 202A via the bridging connection 205, for example periodically, or in response to triggering conditions, such as resynchronization (e.g., resetting the centering timing window). After receiving the link characteristics, the shadow earbud 202A may establish a shadow connection 203 with the audio source device 216 to receive audio data from the audio source device 216.

[0091] At operations 404 and 406, an example of receiving audio data via shadow connection 203 is provided. At operation 404, audio source device 216 may provide audio data to main earbud 202B via first connection 201 (e.g., via a communication packet addressing main earbud 202B). At operation 406, shadow earbud 202A receives audio data, although shadow earbud 202A may be addressed to main earbud 202B. For example, shadow earbud 202A may use the link characteristics received at operation 402 to monitor first connection 201. Operations 404 and 406 may be repeated as long as shadow connection 203 remains present and first connection 201 remains active.

[0092] At operation 408, the main earbud 202B receives audio data, but the shadow earbud 202A fails to detect the audio data (e.g., operation 410 fails to deliver audio data to the shadow earbud 202A). At operation 412, the shadow earbud 202A detects the failure to receive audio data on the shadow connection 203. For example, the failure detection may be in response to the elapsed time of a predetermined period or an integer (one or more) of the RX window 302 of the shadow connection 203 without receiving audio data. Furthermore, at operation 412, the shadow earbud 202A may use a timing relationship to synchronize the timing window communicating with the audio source device 216. For example, the shadow earbud 202A may maintain the timing relationship without expanding the RX window 302, or it may expand the timer to remain active.

[0093] In some embodiments, as depicted at operation 414, the shadow earbud 202A receives an indication of received audio data via bridging connection 205. This indication may be provided as a bit flag indicating reception (or non-reception), reception time or associated timing window adjustment or non-adjustment, or the audio data itself. In some embodiments, the indication provided from the main earbud 202B to the shadow earbud 202A is provided in response to a request from the shadow earbud 202A, which may relay the request in response to a failure to detect audio data. Therefore, the relay of indications (e.g., audio data) can be avoided if the shadow connection 203 is not degraded. This conserves the battery life of the main earbud 202B by avoiding external transmission of audio data, even if the bridging connection 205 is provided via a relatively low-power link. When audio data is transmitted at operation 414, the audio data can be the audio data of operations 408 and 410, or subsequent audio data (e.g., taking into account the delay in detecting the failure to receive audio data on shadow connection 203, taking into account the audio buffer of shadow earbud 202A, etc.).

[0094] In response to an instruction received from the master earbud 202B, the shadow earbud 202A may maintain or adjust the timing relationship between the bridging connection 205 and the shadow connection 203. For example, the shadow earbud 202A may determine that the audio received by the master earbud 202B during the pre-scheduled transmission time has not been drifted. In some embodiments, the shadow earbud 202A may further verify whether drift exists between the earbuds 202, but this operation may be omitted in some embodiments. For example, according to some embodiments of this disclosure, when the respective earbuds 202 contain the same or similar design, components, and environment, earbud drift may not be compensated. Operation 414 may be repeated any number of times (e.g., for any number of audio packets or other instructions), during which time the shadow earbud 202A may maintain the timing relationship of the shadow connection (e.g., RX window 302) and may continue to extend (e.g., reset) the supervisory timer immediately after receiving audio data.

[0095] In some cases, the shadow connection 203 may be re-established before operation 416 is performed, for example, due to the removal of obstacle 220, reorientation of the antenna, or reduction of the distance between the audio source device 216 and the shadow earbud 202A. Therefore, at operation 416, similar to operation 404, the main earbud 202B can receive audio data. At operation 418, the shadow earbud 202A can receive audio data. In some embodiments, the shadow earbud 202A can communicate the re-establishment of the shadow connection with the main earbud 202B, so the main earbud 202B can stop the transmission of audio data (or instruct other transmissions to receive audio data). In some instances, such as if operation 416 does not occur before a timer (e.g., a five-second monitoring timer or a five-minute monitoring timer) expires, the shadow earbud 202A may transition to an inactive state without adjusting the RX window 302, as this might unnecessarily reduce battery life.

[0096] Figure 5This is a flowchart of method 500 according to some embodiments. Method 500 may be performed by at least one of a pair of earbuds 202 (sometimes referred to as shadow earbud 202A). Method 500 may be performed in conjunction with other devices, such as a main earbud 202B of a pair of earbuds 202 including shadow earbud 202A and a mobile phone or other audio source device 216. The operations provided below are not intended to be limiting. According to various embodiments, method 500 may add, replace, modify or omit one or more operations according to various aspects of this disclosure or otherwise. For example, although not explicitly described as operations of method 500, method 500 may include: identifying one earbud in a pair of earbuds as main earbud 202B and identifying the other earbud in the pair as shadow earbud 202A. For example, main earbud 202B and shadow earbud 202A may be determined according to various arbitration techniques described herein. In fact, various operations may be modified according to various aspects of this disclosure.

[0097] At operation 505, the primary earbud 202B of the pair of earbuds establishes a first connection 201 with a device (e.g., a mobile phone or other audio source device 216). The primary earbud 202B can receive audio data from the device via the first connection 201.

[0098] The audio data may include packetized audio data that can be received via various connection protocols. For example, the first connection may be established as a Bluetooth link between the device and the main earbud 202B. Bluetooth or other connection types may be initiated by the main earbud 202B or the device. In some embodiments, the establishment of the first connection 201 may include pairing of the main earbud 202B (or smart shell, shadow earbud 202A, etc.). However, the establishment of the first connection 201 at operation 505 does not need to include such pairing. For example, in some embodiments, pairing may be performed before operation 505 or separately from operation 505. That is, the establishment of the first connection 201 at operation 505 may rely on previously negotiated credentials or link characteristics, or be based on other pre-established credentials or link characteristics.

[0099] At operation 510, the main earbud 202B and the shadow earbud 202A establish a bridging connection 205 therebetween. Similar to the first connection 201, the link characteristics of the bridging connection 205 may or may not be negotiated at the time of establishment. For example, in some embodiments, the link characteristics of the bridging connection 205 may be provided to each of the pair of earbuds during or after manufacturing (e.g., in conjunction with a smart shell). According to various embodiments, the bridging connection 205 may be implemented according to various connection types. For example, in some embodiments, the bridging connection 205 is established as a Bluetooth link between the main earbud 202B and the shadow earbud 202A.

[0100] The bridging connection 205 can be a lower power connection than the first connection, even if both connections are of the same type (e.g., both are Bluetooth links). For example, the first connection may be implemented as a Bluetooth Classic link (e.g., Advanced Audio Distribution Profile A2DP), while the bridging connection may be implemented according to an LE2M link.

[0101] After bridging connection 205 is established, the shadow earbud 202A can immediately receive audio link characteristics or audio data of the first connection 201 from the main earbud 202B via bridging connection 205. The audio link characteristics of the first connection 201 may include any information that the shadow earbud 202A can use to monitor the first connection 201. For example, link characteristics may include timing relationships (e.g., RX window position, link key, session key, address (e.g., BD_ADDR), frequency hopping parameters, packet structure, codec). In some embodiments, the link characteristics received by the shadow earbud 202A may include credentials, such as encrypted or other authentication data, such as a password or PIN that may have been exchanged between the main earbud 202B and the audio source device 216 during pairing.

[0102] The audio data provided via bridging connection 205 may include packetized audio data or its timing information, such as the transmission time. In some embodiments, shadow earbud 202A is configured to request the transmission of audio data in response to a failure to receive expected audio data via shadow connection 203. This handshake avoids retransmission of audio data to shadow earbud 202A, in which shadow connection 203 is not degraded, so as to avoid irrelevant retransmissions by the main earbud 202B.

[0103] After receiving the link characteristics, the shadow earbud 202A can establish a shadow connection 203 (e.g., monitor the first connection 201). For example, the shadow earbud 202A can passively monitor the first connection 201 to detect audio data being sent from the audio source device 216 to the main earbud 202B. In embodiments, the link characteristics include one or more credentials, and the shadow earbud 202A can use one or more credentials to establish the shadow connection 203.

[0104] In some embodiments, the lower-power link of bridging connection 205 may exhibit reduced bandwidth relative to the first connection 201. However, the amount of data provided through bridging connection 205 may be less than that provided by the first connection. For example, in some embodiments, the main earbud 202B may use low-bandwidth techniques to provide audio data to the shadow earbud 202A, such as by using a low-complexity communication codec (LC3), or by providing an indication of audio reception without providing the audio data itself. In some embodiments, the lower-power link of bridging connection 205 may exhibit reduced communication range relative to the first connection 201. However, since the earbuds are used generally close to each other, bridging connection 205 can remain active even if the first connection 201 is degraded due to the range or presence of obstacle 220.

[0105] At operation 515, the shadow earbud 202A can maintain a timing relationship between the bridging connection 205 and the shadow connection 203. In some embodiments, the shadow earbud 202A can maintain the timing relationship based on audio data received via the shadow connection. For example, in the event that a timer drift (e.g., oscillator drift) causes audio data to be received later or earlier than expected, the shadow earbud 202A can adjust the RX window 302 to synchronize with the received audio data (e.g., by recentering the audio data into the RX window 302). In the event that no audio data is received, such as at a subsequent operation 520, the shadow earbud 202A can use the audio data received via the bridging connection 205 or other indications to maintain the timing relationship. For example, the shadow earbud 202A can determine that audio data is provided within the RX window 302 based on audio data received from the main earbud 202B (because the main earbud 202B will receive audio data during the same RX window 302). In some embodiments, the shadow earbud 202A may determine the timing relationship based on an adjustment or non-adjustment flag or other indication of the RX window 302.

[0106] In some embodiments, the timing relationship may include a timer, such as a regulatory timer for shadow connection 203 (or generally shadow earbud 202A). Maintaining the timing relationship helps prevent the timer from expiring. For example, shadow earbud 202A may extend (e.g., reset) a timer that defines the duration for which shadow earbud 202A remains active, and shadow earbud 202A may receive audio data via shadow connection 203. The extension of the timer may be in response to the detection of audio data detected via at least one of shadow connection 203 or bridging connection 205.

[0107] At operation 520, the shadow earbud 202A detects a failure to receive data on the shadow connection 203. As indicated above, the detected failure delays the extension of the timer. Therefore, the shadow earbud 202A can transition to an inactive state in response to the expiration of the timer. Transitioning to an inactive state helps maintain battery life and lower power consumption. For example, in some embodiments, the shadow earbud 202A can transition to an inactive state without extending the RX window 302 and without incurring associated power consumption and media congestion.

[0108] At operation 525, the shadow earbud 202A can use timing relationships to synchronize the timing window for communication with the device. For example, by extending the time the shadow earbud 202A remains active, the shadow earbud can receive subsequent audio data via shadow connection 203 (e.g., detecting the recovery of audio data). Similarly, by performing any adjustments to the RX window 302, the shadow earbud 202A can maintain synchronization with the device to facilitate subsequent reception of audio data. Therefore, the shadow earbud 202A can communicate with the device (e.g., receiving audio data during an adjusted or unadjusted RX window) when the antenna is redirected, obstruction 220 is removed, or the range between the device transmitting audio data and the shadow earbud 202A is reduced.

[0109] In some embodiments, the shadow earbud 202A may adjust timing relationships upon receiving audio data, for example, by extending a timer or adjusting the RX window to compensate for any packets not received via shadow connection 203 (e.g., packets received via bridging connection 205). In some embodiments, the shadow earbud 202A detects an indication of the status of the first connection 201 via bridging connection 205. For example, the indication may be provided as audio data or a flag indicating the health of the first connection 201. In response to detecting the indication, the shadow earbud 202A may extend a timer during which the shadow earbud receives audio data via the shadow connection to maintain an active state. For example, since the first connection 201 is active, the shadow earbud 202A may wait for additional audio data.

[0110] A reference to “or” can be interpreted as inclusive, such that any term described using “or” can refer to a single, more than one, or any of all descriptive terms. A reference to at least one of a list of combinations of terms can be interpreted as an inclusive “or” to indicate a single, more than one, or any of all descriptive terms. For example, a reference to “at least one of 'A' and 'B'” can include only “A”, only “B”, or both “A” and “B”. Such references used in conjunction with “include” or other open-ended terms can include additional items.

[0111] It should be noted that certain paragraphs of this disclosure may refer to terms related to apparatus, mode of operation, transmission chain, etc., such as "first" and "second," for the purpose of identifying or distinguishing one from another or others. These terms are not intended to associate entities (e.g., first apparatus and second apparatus) merely in time or in sequence, although in some cases such a relationship may exist. These terms also do not limit the number of possible entities (e.g., apparatuses) that can operate in the system or environment. The terms "coupled" or "connected" include both indirect and direct coupling and connection.

[0112] It should be understood that the system described above may provide any one or more of those components, and these components may be provided on a standalone machine, or, in some embodiments, on multiple machines in a distributed system. Furthermore, the system and methods described above may be provided as one or more computer-readable programs or executable instructions embodied on or in one or more articles of art. The articles of art may be floppy disks, hard disks, CD-ROMs, flash memory cards, PROMs, RAM, ROMs, or magnetic tapes. Generally, the computer-readable program may be implemented in any programming language (e.g., LISP, PERL, C, C++, C#, PROLOG) or in any bytecode language (e.g., JAVA). The software program or executable instructions may be stored as object code on or in one or more articles of art.

[0113] While the prior written description of the methods and systems enables those skilled in the art to make and use the methods and systems currently considered best practices, those skilled in the art will understand and appreciate that variations, combinations, and equivalents of specific embodiments, methods, and examples exist herein. Therefore, the methods and systems should not be limited to the embodiments, methods, and examples described above, but rather to all embodiments and methods within the scope and spirit of this disclosure. The headings provided in this document are non-limiting.

[0114] The application and server have been described above using functional building blocks to illustrate the performance of certain important functions. For ease of description, the boundaries of these functional building blocks are arbitrarily defined. Functions and structures can be integrated across such boundaries. Alternative boundaries can be defined as long as certain important functions are properly performed. Similarly, flowchart blocks can also be arbitrarily defined herein to illustrate certain important functionalities. Flow boundaries and sequences can be defined in other ways, depending on the extent to which they are used, while still performing certain important functionalities. Therefore, such alternative definitions of functional building blocks, flowchart blocks, and sequences are within the scope and spirit of the claimed invention. Those skilled in the art will also recognize that the functional building blocks and other illustrative blocks, modules, and components described herein can be implemented as illustrated, or implemented via discrete components, application-specific integrated circuits, processors executing appropriate software, etc., or any combination thereof.

Claims

1. A system comprising: Main earbud, the main earbud being configured to: Establish a first connection with the device, the first connection being configured to transmit audio data from the device to the main earbud; and Establish a bridging connection with the shadow device, the bridging connection being configured to transmit link characteristics including a timing window for the first connection; and Shadow earbuds, the shadow earbuds being configured to: Detecting failures to receive the audio data during the same timing window; The timing window is maintained at least based on an indication of the status of the first connection received via the bridging connection to allow the shadow connection to receive the audio data; and Use the same timing window to receive subsequent audio data.

2. The system according to claim 1, wherein: The shadow earplug is configured to: In response to detecting a first packet of a plurality of packets carrying the audio data via the shadow connection, a timer is extended during which the shadow earbud will receive the audio data via the shadow connection to maintain an active state; The timer expires if no further or subsequent one or more packets are detected; and In response to the expiration of the timer, it transitions to a lower power state or mode.

3. The system of claim 2, wherein the shadow earplug is configured to: In response to detecting a second packet among the plurality of packets via the bridging connection, the timer is extended.

4. The system of claim 1, wherein the shadow earplug is configured to: The timing window is adjusted based on the data received via the bridging connection.

5. The system of claim 4, wherein the data received via the bridging connection includes packets, the packets including a portion of the audio data.

6. The system according to claim 1, wherein: The first connection is a first Bluetooth link between the device and the main earbud; and The bridging connection is a second Bluetooth link between the main earbud and the shadow earbud, wherein the second Bluetooth link is a lower power connection than the first Bluetooth link.

7. An apparatus comprising: An audio output device is configured to: Negotiate one of multiple roles with the second audio output device, the multiple roles corresponding to the main mode and shadow mode between the audio output device and the second audio output device; During the main mode: Establish a first connection with an audio source device, the first connection being configured to transmit audio data from the audio source device to the audio output device; and Establish a bridged connection with the second audio output device, the bridged connection being configured to pass the link characteristics used for the first connection; and During the shadow mode: The first connection is monitored using the link characteristics via a shadow connection to detect a timing window for the audio data; Detect a failure to receive the audio data on the shadow connection during the timing window; and In response to receiving a packet including the audio data via the bridging connection, a timer is extended during which the audio output device will receive the audio data via the shadow connection to maintain an active state.

8. The apparatus according to claim 7, further configured as follows: In the shadow mode, the timer is extended in response to receiving a packet containing the audio data via the shadow connection.

9. The apparatus according to claim 7, further configured as follows: During the main mode, the audio data received via the first connection is transmitted to the second audio output device via the bridging connection; and During the shadow mode, if no audio data is received during the timing window, the system transitions to an inactive state in response to the expiration of the timer.

10. The apparatus according to claim 7, wherein: The first connection is a first Bluetooth link between the audio source device and the audio output device; and The bridging connection is a second Bluetooth link between the audio output device and the second audio output device, wherein the second Bluetooth link is a lower power connection than the first Bluetooth link.

11. A method comprising: A first connection to the device is established by the main earbud of a pair of earbuds, and the main earbud receives audio data from the device via the first connection; A bridging connection is established between the main earbud and the shadow earbud. The shadow earbud receives the audio data and link characteristics via the bridging connection to establish a shadow connection with the device in order to receive the audio data from the device. The timing relationship between the bridging connection and the shadow connection is maintained by the shadow earpiece; The shadow earpiece detects the failure to receive data on the shadow connection; and The shadow earpiece uses the timing relationship to synchronize the timing window in order to communicate with the device within the timing window.

12. The method of claim 11, further comprising: Following the failure, the recovery of the audio data is detected by the shadow earpiece; and The timing relationship is adjusted by the shadow earplug to resynchronize with the device.

13. The method of claim 12, further comprising: Following the failure to receive the audio data and before its recovery, the shadow earpiece detects an indication of the status of the first connection via the bridging connection; and In response to the detection indicated, the shadow earbud extends a timer during which the shadow earbud receives the audio data via the shadow connection to maintain an active state.

14. The method of claim 13, further comprising: The instruction, including the audio data, is transmitted from the main earpiece to the shadow earpiece.

15. The method of claim 11, further comprising: The audio data is detected via at least one of the shadow connection or the bridge connection; and In response to the detection of the audio data, a timer is extended, during which the shadow earbud will receive the audio data via the shadow connection to maintain its active state.

16. The method of claim 11, further comprising: It transitions to an inactive state in response to the expiration of a timer for at least one of the shadow connection or the bridge connection.

17. The method of claim 11, wherein the shadow earplug is configured to: Receive credentials from the main earbud via the bridging connection; and Use the credentials to establish the shadow connection.

18. The method according to claim 11, wherein: The first connection is a first Bluetooth link between the device and the main earbud; and The bridging connection is a second Bluetooth link between the main earbud and the shadow earbud.

19. The method of claim 18, wherein the second Bluetooth link is a lower power connection than the first Bluetooth link.

20. The method of claim 11, further comprising: Between the pair of earplugs: The first earbud of the pair of earbuds is identified as the main earbud; and The second earbud in the pair is identified as the shadow earbud.

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