Synchronization of audio channel timing

Abstract

Synchronization of plural outputs of data transported by a wireless network is facilitated by bandlimiting a sample clock signal controlling a rate at which data is processed by the network's devices and/or bandlimiting wall time data controlling the real time for presenting a datum.

I (we) claim: 
     
         1 . An audio system comprising:
 (a) a first listener including:
 (i) a wall clock maintaining a wall time for occurrence of an event, said wall time updated by data transmitted by a master clock and received by said first listener; 
 (ii) a sample clock recoverer retrieving a sample clock from data received by said first listener from a talker, said sample clock regulating a processing rate for a datum included in said data received from said talker; and 
 (iii) a frequency filter bandlimiting said sample clock output by said sample clock recoverer; and 
 (iv) a transmitter transmitting said bandlimited sample clock; and 
   (b) a second listener arranged to receive said transmitted bandlimited sample clock and use said bandlimited sample clock to regulate processing data received from said talker.   
     
     
         2 . The audio system of  claim 1  wherein said frequency filter comprises a low band width phase locked loop connected to receive said sample clock output by said sample clock recoverer. 
     
     
         3 . The audio system of  claim 1  wherein the first listener further comprises a frequency filter attenuating a frequency of said updating data received from said master clock. 
     
     
         4 . The audio system of  claim 3  wherein said updating data received from said master clock comprises a timing synchronization function datum. 
     
     
         5 . The audio system of  claim 3  wherein said updating datum received from said master clock comprises a precision time protocol datum. 
     
     
         6 . An audio system comprising:
 (a) a first listener including:
 (i) a wall clock maintaining a wall time for occurrence of an event, said wall time updated by a data transmitted by a master clock and received by said first listener; 
 (ii) a frequency filter bandlimiting said updating data received from said master clock and said wall time; and 
 (iii) a sample clock recoverer retrieving a sample clock from data received by said first listener from a talker, said sample clock regulating a processing rate for a datum included in said data received from said talker; and 
 (iv) a transmitter transmitting said bandlimited wall time; and 
   (b) a second listener arranged to receive said bandlimited wall time and to use said bandlimited wall time to recover a sample clock from data received from said talker.   
     
     
         7 . The audio system of  claim 6  wherein said frequency filter comprises a low band width phase locked loop arranged to receive said updating data received from said master clock. 
     
     
         8 . The audio system of  claim 6  wherein said updating data received from said master clock comprises a timing synchronization function datum. 
     
     
         9 . The audio system of  claim 6  wherein said updating datum received from said master clock comprises a precision time protocol datum. 
     
     
         10 . A method of recovering a sample clock in a network, said method comprising the steps of:
 (a) generating a raw sample clock signal oscillating at a frequency determined by a datum included in a data packet; and   (b) bandlimiting said raw sample clock signal about the mean frequency of said raw sample clock signal by frequency filtering said raw sample clock signal.   
     
     
         11 . A method of recovering a sample clock in a network, said method comprising the steps of:
 (a) bandlimiting said raw wall time signal about the mean frequency of said raw wall time signal by frequency filtering said raw wall time signal; and   (b) generating a sample clock signal oscillating at a frequency determined by a datum included in a data packet and said bandlimited raw wall time signal.   
     
     
         12 . The method of recovering a sample clock of  claim 11  further comprising the step of frequency filtering said sample clock signal.