# US 2013/0158692 A1 · Adaptive Isochronous USB Audio To RF Communication Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0158692 A1 - Document ID: US20130158692A1 - Status: Published application - Kind: A1 - Application number: 13/718,298 - Filed: 2012-12-18 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: GN Netcom A/S - Inventors: Rene Elbæk Jensen - Web page: https://patentgrep.com/patent/US20130158692A1 ## CPC - G06F 13/4291: {using a clocked protocol} - G06F 13/102: {where the program performs an interfacing function, e.g. device driver (G06F13/105 takes precedence; contention policies within device drivers G06F9/4881; scheduling within device drivers G06F9/52)} - G06F 17/00: Digital computing or data processing equipment or methods, specially adapted for specific functions (information retrieval, database structures or file system structures therefor G06F16/00) - H04L 7/02: Speed or phase control by the received code signals, the signals containing no special synchronisation information {(H04L7/0075 takes precedence)} - H04L 7/04: Speed or phase control by synchronisation signals {(H04L7/0075 takes precedence)} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method of and a system for synchronizing isochronous audio data frames provided by a USB interface to a clock of a wireless RF communication device is provided. The USB interface and the wireless RF communication device are connected via an I2S link, the method comprising receiving the isochronous audio data frames and the wireless RF communication device clock in a streaming controller, phase locking the isochronous audio data frames to a USB interface clock, counting start-of-frame pulses of the phase locked isochronous audio data frames, comparing the counted start-of-frame pulses with the wireless RF communication device clock to determine a difference signal, the difference signal triggering a synchronization event code when a threshold difference has been reached, rate matching the isochronous audio data frames to the wireless RF communication device clock upon receiving the synchronization event code. ## Claims ### Claim 1 A method of synchronizing isochronous audio data frames provided by a USB interface to a clock of a wireless RF communication device, the USB interface and the wireless RF communication device being connected via a serial audio link, the method comprising: receiving the isochronous audio data frames and the wireless RF communication device clock, synchronizing a data rate of the isochronous audio data frames to a USB interface clock, counting start-of-frame pulses of the synchronized isochronous audio data frames, comparing the counted start-of-frame pulses with the wireless RF communication device clock to determine a difference signal, the difference signal triggering a synchronization event code when a threshold difference has been reached, rate matching the isochronous audio data frames to the wireless RF communication device clock upon receiving the synchronization event code. ### Claim 2 (depends on 1) A method according to claim 1, wherein the serial audio link is an Inter IC-sound bus. ### Claim 3 (depends on 1) A method according to claim 1, wherein the data rate of the isochronous audio data frames is synchronized to the USB interface clock using a phase locked loop. ### Claim 4 (depends on 1) A method according to claim 1, where in the rate matching is performed using fractional down- and up-sampling—i.e. by inserting or removing an audio sample. ### Claim 5 (depends on 1) A method according to claim 1, wherein the start-of-frame pulses are synchronous with a receipt of start-of-frame packets. ### Claim 6 (depends on 1) A method according to claim 1, wherein the wireless RF communication device is a wireless hub. ### Claim 7 (depends on 6) A method according to claim 6, wherein the wireless hub is configured to communicate with a headset. ### Claim 8 (depends on 1) A method according to claim 1, wherein the isochronous audio data frames are low-latency frames. ### Claim 9 (depends on 1) A method according to claim 1, wherein the streaming controller is adaptive to the USB interface. ### Claim 10 (depends on 1) A method according to claim 1, wherein the synchronization event code comprises an interrupt. ### Claim 11 (depends on 1) A method according to claim 1, wherein the start-of-frame pulse is detected at predetermined time intervals, such as every 1 millisecond. ### Claim 12 A system configured to provide audio data frames between a USB interface and a wireless RF communication device, the system comprising a USB interface having adaptive endpoints providing start-of-frame pulses to an adaptive streaming controller, a serial audio link connecting the USB interface to the wireless RF communication device, the wireless RF communication device having an RF transceiver, and a wireless RF communication device clock generator, a processor configured to receive and compare the wireless RF communication device clock and the start-of-frame pulses to determine a clock difference signal, the clock difference signal triggering a synchronization event code when a threshold difference has been reached, and configured to generate a rate match output to synchronize the audio stream to the wireless RF communication device clock upon triggering. ### Claim 13 (depends on 12) A system according to claim 12, wherein the start-of-frame pulses are synchronous with the receipt of start-of-frame packets. ### Claim 14 (depends on 12) A system according to claim 12, wherein the wireless RF communication device clock is a master clock for the serial audio link. ### Claim 15 A synchronized communication system comprising a wireless RF communication device and a USB interface, the system comprising a streaming controller configured to receive isochronous audio data frames provided by the USB interface and a wireless RF communication device clock, a serial audio link interconnecting at least the streaming controller and the wireless RF communication device, a phase locked loop configured to phase lock the isochronous audio data frames to a USB interface clock, a counter configured to count start-of-frame pulses of the phase locked isochronous audio frames, a comparator for comparing the counted start-of-frame pulses with the RF communication device clock to determine a clock difference signal, the clock difference signal triggering a synchronization event code when a threshold difference has been reached, a rate matching entity configured to rate match the isochronous audio data frames to the RF communication device clock upon receiving the synchronization event code to thereby synchronize the audio data frames with the wireless RF communication device clock. ### Claim 16 (depends on 1) A method according to claim 1, wherein the steps of receiving the isochronous audio data frames and the wireless RF communication device clock, synchronizing a data rate of the isochronous audio data frames to a USB interface clock, counting start-of-frame pulses of the synchronized isochronous audio data frames, comparing the counted start-of-frame pulses with the wireless RF communication device clock to determine a difference signal, the difference signal triggering a synchronization event code when a threshold difference has been reached, and rate matching the isochronous audio data frames to the wireless RF communication device clock upon receiving the synchronization event code are performed by a streaming controller configured to connect the USB interface and the wireless RF communication device. ### Claim 17 (depends on 16) A method according to claim 16, including a USB interface having adaptive endpoints providing start-of-frame pulses to an adaptive streaming controller and wherein the streaming controller is adaptive to the USB interface.