Method for streaming through a data service over a radio link subsystem

Abstract

An apparatus for controlling a data rate in a data client for a digital audio broadcasting system includes a buffer for storing data, a codec for coding data, and a control module for controlling a bit rate of the codec in response to a level of the data in the buffer. A method performed by the apparatus is also included.

1 .- 18 . (canceled) 
     
     
         19 . A radio signal broadcasting system, the system comprising:
 a radio frequency (RF) transmitter operatively configured to broadcast an in-band on-channel (IBOC) analog broadcast signal via an RF channel, and stream video data via at least one sub-channel of the first RF channel;   a studio transmitter link (STL) to the RF transmitter, the STL including:
 a buffer configured to store service data for streaming, including the video data, via the at least one sub-channel of the RF channel; 
 a codec configured for encoding the service data for streaming; and 
 a control module configured for controlling a bit rate of the codec in response to a fill level of the service data in the buffer. 
   
     
     
         20 . The system of  claim 19 , wherein the control module is configured to change the bit rate of the codec according to the fill level of the service data in the buffer, wherein the change in bit rate is phase continuous. 
     
     
         21 . The system of  claim 19 , wherein the control module is configured to compare the level of the service data in the buffer to a first threshold level and reduce the bit rate of the codec when the level of the service data in the buffer exceeds the first threshold level. 
     
     
         22 . The system of  claim 21 , wherein the control module is further configured to compare the level of the service data in the buffer to a second threshold level and increase the bit rate of the codec when the level of the service data in the buffer is below the second threshold level. 
     
     
         23 . The system of  claim 19 , wherein the control module is configured to compare the level of the service data in the buffer to a second threshold level and suspend requests for service data when the level of the service data in the buffer is below the second threshold level. 
     
     
         24 . The system of  claim 19 , wherein the STL includes an importer operatively coupled to the codec, wherein the buffer receives the service data at a first data rate and the importer requests service data from the buffer at a second data rate, and wherein the second data rate is determined according to a transmit data rate of the at least one sub-channel of the RF channel. 
     
     
         25 . The system of  claim 24 , including an exporter configured to multiplex the streaming service data with main program audio data to generate an output signal, wherein the exporter requests data from the importer at the second data rate. 
     
     
         26 . The system of  claim 24 , wherein the buffer is configured to receive the video data from a video data source, and wherein access to the buffer by the service data source is asynchronous to access to the buffer by the codec. 
     
     
         27 . The system of  claim 24 , wherein the control module compares the level of the service data in the buffer to a second threshold level and suspends requests for the service data by the importer when the level of the service data in the buffer is below the second threshold level. 
     
     
         28 . The system of  claim 19 , wherein the control module is configured for controlling a compression rate of the codec in response to a fill level of the service data in the buffer. 
     
     
         29 . A method for controlling a data rate in a radio signal broadcasting system, the method comprising:
 broadcasting an in-band on-channel (IBOC) analog broadcast signal via a radio frequency (RF) channel using an RF transmitter;   streaming service data via at least one sub-channel of the RF channel simultaneously with the broadcasting, wherein the service data includes video data;   buffering the service data for the streaming;   encoding the buffered service data for streaming using a codec; and   controlling a bit rate of the codec according to a buffered level of the service data.   
     
     
         30 . The method of  claim 29 , wherein the controlling the bit rate of the codec includes changing the bit rate of the codec in response to a fill level of the service data in a buffer, wherein the change in bit rate of the codec is phase continuous. 
     
     
         31 . The method of  claim 29 , wherein the controlling the bit rate of the codec includes comparing the buffered level of the service data to a first threshold level and decreasing the bit rate of the codec when the buffered level of the service data exceeds the first threshold level. 
     
     
         32 . The method of  claim 31 , wherein the controlling the bit rate of the codec includes comparing the buffered level of the service data to a second threshold level and increasing the bit rate of the codec when the buffered level of the service data is less than the second threshold level. 
     
     
         33 . The method of  claim 29 , wherein the controlling the bit rate of the codec includes comparing the buffered level of the service data to a second threshold level and suspending requests for buffered service data when the level of the service data is below the second threshold level. 
     
     
         34 . The method of  claim 29 , wherein the buffering the service data for streaming includes placing the service data in a buffer at a first data rate, wherein the streaming the service data includes requesting the service data for streaming from the buffer at a second data rate different from the first data rate, and wherein the second data rate is determined according to a transmit data rate of the at least one sub-channel of the RF channel. 
     
     
         35 . The method of  claim 29 , wherein the streaming the service data includes multiplexing the streaming service data with digital audio data to generate multiplexed data in an output signal transmitted by the RF transmitter. 
     
     
         36 . The method of  claim 29 , wherein the buffering the service data for the streaming includes receiving the video data from a video data source for buffering, and wherein encoding the buffered service data includes accessing the buffered video data asynchronously to the buffering of the video data. 
     
     
         37 . The method of  claim 29 , wherein the controlling a bit rate of the codec includes controlling a compression rate of the codec in response to the buffered level of the service data. 
     
     
         38 . The method of  claim 29 , wherein the broadcasting the IBOC analog broadcast signal includes broadcasting the IBOC analog signal at a transmitter site, and wherein the buffering the service data for streaming includes buffering the service data for streaming at a studio site remote from the transmitter site.