Dynamic forward error correction

Abstract

A forward error correction (FEC) method is provided including an FEC dynamic central station and a plurality of FEC dynamic remote stations that transmit bearer data and corresponding error correction data therebetween during a plurality of time frames. The error rate of the communication channel is measured and the amount of error correction data transmitted is accordingly and dynamically adjusted, so that the minimum amount of overhead required to effectively transmit the error correction data is used.

1. A method of selecting an error correction algorithm in a communications system, the method comprising:
 dividing each time frame of a multi-frame into a plurality of time slots; 
 determining an error rate level of a communication channel based on a plurality of bearer data packets when received during said multi-frame; 
 selecting an error correction algorithm from a plurality of error correction algorithms taking into account said error rate level; 
 determining the dynamic quality of said communication channel; and 
 adjusting the number of time frames in a multi-frame based on said dynamic quality. 
 
     
     
       2. The method of  claim 1 , wherein said plurality of bearer data packets comprises traffic data. 
     
     
       3. The method of  claim 2 , wherein said selected error correction algorithm has an overhead level, and wherein the amount of said traffic data is inversely varied with said overhead. 
     
     
       4. The method of  claim 1 , and wherein said error rate level determination comprises correcting said plurality of bearer data packets and detecting a number of defective bearer data packets to obtain a current block error rate (BLER) level, and wherein said error correction algorithm determination is based on said current BLER level. 
     
     
       5. The method of  claim 4 , wherein said error correction algorithm selection comprises setting a minimum BLER threshold level and a maximum BLER threshold level to create an acceptable BLER range, selecting a current error correction algorithm if said acceptable BLER range includes said current BLER level and selecting an error correction algorithm different from said current error correction algorithm if said acceptable BLER range does not include said current BLER level. 
     
     
       6. The method of  claim 5 , wherein said plurality of error correction algorithm comprise algorithms comprises differing overhead levels, and said error correction algorithm determination further comprises selecting an error correction algorithm with a next lower overhead than that of said current error correction algorithm if said current BLER level is below said minimum BLER threshold level and selecting an error correction algorithm with a next higher overhead than that of said current error correction algorithm if said current BLER level is above said maximum BLER threshold level. 
     
     
       7. The method of  claim 1 , wherein said error rate level determination comprises detecting a number of bit errors in said plurality of bearer data packets to obtain a bit error rate (BER) level, and wherein said error rate level determination is based on said current BER level. 
     
     
       8. The method of  claim 7 , wherein said error correction algorithm selection comprises setting at least one BER threshold level to create a plurality of BER ranges corresponding to the plurality of error correction algorithmns algorithms, and selecting an error correction algorithm that corresponds to the BER range that includes the current BER level. 
     
     
       9. The method of  claim 1 , wherein each bearer data packet of said plurality of bearer data packets is respectively received during a time slot of said each time frame of said multi-frame, and wherein said error correction algorithm selection comprises selecting said error correction algorithm during the last time frame of said multi-frame. 
     
     
       10. The method of  claim 1 , wherein said plurality of error correction algorithms includes an algorithm which, when used, does not by itself correct any errors. 
     
     
       11. The method of  claim 1 , wherein said plurality of error correction algorithms includes an algorithm which, when used, does not by itself correct any errors, a low-level error correction algorithm and a high-level error correction algorithm. 
     
     
       12. The method of  claim 1 , wherein said plurality of bearer data packets are wirelessly transmitted between a central station and a remote station. 
     
     
       13. An article, comprising:
 a non-transitory processor accessible medium having stored thereon instructions that, when executed by a processor, result in selecting an error correction algorithm in a communications system by:
 dividing each time frame of a multi-frame into a plurality of time slots; 
 determining an error rate level of a communication channel based on a plurality of bearer data packets when received during said multi-frame; 
 selecting an error correction algorithm from a plurality of error correction algorithms taking into account said error rate level; 
 determining the dynamic quality of said communication channel; and 
 adjusting the number of time frames in a multi-frame based on said dynamic quality.  
   
     
     
       14. The article of claim 13, wherein each bearer data packet of said plurality of bearer data packets is respectively received during a time slot of said each time frame of said multi-frame, and wherein said error correction algorithm selection comprises selecting said error correction algorithm during the last time frame of said multi-frame.  
     
     
       15. The article of claim 13, wherein said plurality of error correction algorithms includes an algorithm which, when used, does not by itself correct any errors.  
     
     
       16. The article of claim 13, wherein said plurality of error correction algorithms includes an algorithm which, when used, does not correct any errors, a low-level error correction algorithm and a high-level error correction algorithm.  
     
     
       17. The article of claim 13, wherein said plurality of bearer data packets are wirelessly transmitted between a central station and a remote station.  
     
     
       18. The article of claim 13, wherein said plurality of bearer data packets comprises traffic data.  
     
     
       19. The article of claim 18, wherein said selected error correction algorithm has an overhead level, and wherein the amount of said traffic data is inversely varied with said overhead.  
     
     
       20. The article of claim 13, wherein said error rate level determination comprises detecting a number of bit errors in said plurality of bearer data packets to obtain a bit error rate (BER) level, and wherein said error rate level determination is based on said current BER level.  
     
     
       21. The article of claim 20, wherein said error correction algorithm selection comprises setting at least one BER threshold level to create a plurality of BER ranges corresponding to the plurality of error correction algorithms, and selecting an error correction algorithm that corresponds the BER range that includes the current BER level.  
     
     
       22. The article of claim 13, wherein said error rate level determination comprises correcting said plurality of bearer data packets and detecting a number of defective bearer data packets to obtain a current block error rate (BLER) level, and wherein said error correction algorithm determination is based on said current BLER level.  
     
     
       23. The article of claim 22, wherein said error correction algorithm selection comprises setting a minimum BLER threshold level and a maximum BLER threshold level to create an acceptable BLER range, selecting a current error correction algorithm if said acceptable BLER range includes said current BLER level and selecting an error correction algorithm different from said current error correction algorithm if said acceptable BLER range does not include said current BLER level.  
     
     
       24. The article of claim 23, wherein said plurality of error correction algorithms comprises differing overhead levels, and said error correction algorithm determination further comprises selecting an error correction algorithm with a next lower overhead than that of said current error correction algorithm if said current BLER level is below said minimum BLER threshold level and selecting an error correction algorithm with a next higher overhead than that of said current error correction algorithm if said current BLER level is above said maximum BLER threshold level.  
     
     
       25. An apparatus, comprising:
 a receiver to receive bearer data packets; and   a processor to determine an error rate level of a communication channel based on a plurality of bearer data packets when received by said receiver during a multi-frame divided into a plurality of time slots, wherein said processor selects an error correction algorithm from a plurality of error correction algorithms taking into account said error rate level, determines the dynamic quality of said communication channel, and adjusts the number of time frames in a multi-frame based on said dynamic quality.    
     
     
       26. The apparatus of claim 25, wherein each bearer data packet of said plurality of bearer data packets is respectively received during a time slot of said each time frame of said multi-frame, and wherein said error correction algorithm selection comprises selecting said error correction algorithm during the last time frame of said multi-frame.  
     
     
       27. The apparatus of claim 25, wherein said plurality of error correction algorithms includes an algorithm which, when used, does not by itself correct any errors.  
     
     
       28. The apparatus of claim 25, wherein said plurality of error correction algorithms includes an algorithm which, when used, does not by itself correct any errors, a low-level error correction algorithm and a high-level error correction algorithm.  
     
     
       29. The apparatus of claim 25, wherein said plurality of bearer data packets are wirelessly transmitted between a central station and a remote station.  
     
     
       30. The apparatus of claim 25, wherein said plurality of bearer data packets comprises traffic data.  
     
     
       31. The apparatus of claim 30, wherein said selected error correction algorithm has an overhead level, and wherein the amount of said traffic data is inversely varied with said overhead.  
     
     
       32. The apparatus of claim 25, wherein said error rate level determination comprises detecting a number of bit errors in said plurality of bearer data packets to obtain a bit error rate (BER) level, and wherein said error rate level determination is based on said current BER level.  
     
     
       33. The apparatus of claim 32, wherein said error correction algorithm selection comprises setting at least one BER threshold level to create a plurality of BER ranges corresponding to the plurality of error correction algorithms, and selecting an error correction algorithm that corresponds to the BER range that includes the current BER level.  
     
     
       34. The apparatus of claim 25, wherein said error rate level determination comprises correcting said plurality of bearer data packets and detecting a number of defective bearer data packets to obtain a current block error rate (BLER) level, and wherein said error correction algorithm determination is based on said current BLER level.  
     
     
       35. The apparatus of claim 34, wherein said error correction algorithm selection comprises setting a minimum BLER threshold level and a maximum BLER threshold level to create an acceptable BLER range, selecting a current error correction algorithm if said acceptable BLER range includes said current BLER level and selecting an error correction algorithm different from said current error correction algorithm if said acceptable BLER range does not include said current BLER level.  
     
     
       36. The apparatus of claim 35, wherein said plurality of error correction algorithms comprises differing overhead levels, and said error correction algorithm determination further comprises selecting an error correction algorithm with a next lower overhead than that of said current error correction algorithm if said current BLER level is below said minimum BLER threshold level and selecting an error correction algorithm with a next higher overhead than that of said current error correction algorithm if said current BLER level is above said maximum BLER threshold level.