Error handling for named signal events in wireless communications

Abstract

The present invention provides a technique for handling damaged named signal event (NSE) packets that are received in association with a voice over packet based telephony call. The received packets for a telephony call may include voice packets as well as NSE packets. Upon receipt of the packets at a physical layer, the packets are processed at a link layer to detect damaged packets having link layer errors. The incoming packets are sent to an audio application at an application layer for further processing. For damaged packets, link layer error indicia is generated at the link layer and sent to the audio processing application. The audio application will use the link layer error indicia to identify damaged packets or payloads associated with damaged packets, and determine whether the payloads corresponding to the damaged packets include NSE information defining an NSE. Damaged NSE packets are processed accordingly.

1 . A method for handling packets for a telephony call, the method comprising:
 receiving packets associated with a telephony call;   detecting damaged packets among the received packets;   identifying damaged named signal event packets among the detected damaged packets; and   providing error processing for the damaged named signal event packets.   
     
     
         2 . The method of  claim 1 , wherein the received packets comprise named signal event packets and voice packets, the method further comprising providing audio processing for the voice packets and for undamaged named signal event packets. 
     
     
         3 . The method of  claim 2 , wherein the audio processing is provided for damaged and undamaged voice packets. 
     
     
         4 . The method of  claim 1 , wherein identifying damaged named signal packets comprises:
 monitoring a payload of a detected damaged packet to detect named signal event information defining a named signal event in the payload.   
     
     
         5 . The method of  claim 1 , wherein providing error processing comprises discarding a payload of a damaged named signal event packet. 
     
     
         6 . The method of  claim 1 , wherein the received packets are streamed using a real time streaming protocol, the received packets comprising voice packets and named signal event packets. 
     
     
         7 . The method of  claim 1 , wherein a named signal event represents an in-band signaling. 
     
     
         8 . The method of  claim 7 , wherein the named signal event comprises at least one tone. 
     
     
         9 . The method of  claim 8 , wherein the named signal event corresponds to at least one of a ringing signal, a busy signal and a fast busy signal. 
     
     
         10 . The method of  claim 9 , wherein the named signal event corresponds to at least one dual-tone multi-frequency tone. 
     
     
         11 . An apparatus for handling packets for a telephony call, the apparatus comprising:
 a communication interface operable to receive packets associated with a telephony call; and   at least one processor associated with the communication interface and operable:
 to detect damaged packets among the received packets; 
 to identify damaged named signal event packets among the detected damaged packets; and 
 to provide error processing for the damaged named signal event packets. 
   
     
     
         12 . The apparatus of  claim 11 , wherein the received packets comprise named signal event packets and voice packets, the at least one processor being further operable to provide audio processing to the voice packets and to undamaged named signal event packets. 
     
     
         13 . The apparatus of  claim 12 , wherein the at least one processor is operable to provide audio processing for damaged and undamaged voice packets. 
     
     
         14 . The apparatus of  claim 11 , wherein the at least one processor is operable to identify a damaged named signal packet by:
 monitoring a payload of a detected damaged packet to detect named signal event information defining a named signal event in the payload.   
     
     
         15 . The apparatus of  claim 11 , wherein the at least one processor is operable to provide error processing by discarding a payload of a damaged named signal event packet. 
     
     
         16 . The apparatus of  claim 11 , wherein the received packets are streamed using a real time streaming protocol, the received packets comprising voice packets and named signal event packets. 
     
     
         17 . The apparatus of  claim 11 , wherein a named signal event represents an in-band signaling event. 
     
     
         18 . The apparatus of  claim 17 , wherein the named signal event comprises at least one tone. 
     
     
         19 . The apparatus of  claim 18 , wherein the named signal event corresponds to at least one of a ringing signal, a busy signal and a fast busy signal. 
     
     
         20 . The apparatus of  claim 19 , wherein the named signal event corresponds to at least one dual-tone multi-frequency tone.