Recovery from burst packet loss in internet protocol based wireless networks using staggercasting and cross-packet forward error correction

Abstract

A method and apparatus for staggercasting are described including encoding and compressing a first data sequence, packetizing the compressed encoded data sequence to form a data packet, performing forward error correction (FEC) encoding on the data packet in order to generate a second data sequence related to the first data sequence, appending FEC control information as padding to the end of payload data of the data packet, packetizing the second data sequence to form a packet, multicasting the data packet to a first multicast group, multicasting the packet formed using the second data sequence delayed by an offset time to a second multicast group.

1 . A system for transmitting data, comprising:
 a packetizer, said packetizer packetizing said data;   a forward error correction encoder, said forward error correction encoder performing forward error correction (FEC) encoding on said packetized data in order to generate a parity packet, said forward error correction encoder being in communication with said packetizer;   said forward error correction encoder appending FEC control information as padding to the end of payload data of said packetized data, said FEC control information including a padding length, a source block number and an encoding unit ID, said forward error correction encoder being in communication with a buffer, said buffer being in communication with a protocol stack;   a communications interface, said communications interface transmitting said packetized data and said parity packet, said communications interface being in communication with said protocol stack.   
     
     
         2 . The system according to  claim 1 , further comprising said buffer delaying transmission of said parity packet for a pre-determined offset time period after transmission of said packetized data. 
     
     
         3 . A method for staggercasting, said method comprising:
 encoding and compressing a first data sequence;   packetizing said compressed encoded data sequence to form a data packet;   performing forward error correction (FEC) encoding on said data packet in order to generate a second data sequence related to said first data sequence;   appending FEC control information as padding to the end of payload data of said data packet;   packetizing said second data sequence to form a packet;   multicasting said data packet to a first multicast group;   multicasting said packet formed using said second data sequence delayed by an offset time to a second multicast group.   
     
     
         4 . The method according to  claim 3 , wherein said second data sequence is a parity packet. 
     
     
         5 . An apparatus for staggercasting, said method comprising:
 a video encoder, said video encoder encoding and compressing a first data sequence;   a packetizer, said packetizer packetizing said compressed encoded data sequence to form a data packet, said packetizer being in communication with said video encoder;   a forward error correction encoder, said forward error correction encoder performing forward error correction (FEC) encoding on said data packet in order to generate a second data sequence related to said first data sequence, said forward error correction encoder being in communication with said packetizer;   said forward error correction encoder appending FEC control information as padding to the end of payload data of said data packet, said forward error correction encoder being in communication with a buffer, said buffer being in communication with a protocol stack;   said packetizer packetizing said second data sequence to form a packet;   a communication interface, said communications interface multicasting said data packet to a first multicast group, said communications interface being in communication with said protocol stack;   said communications interface multicasting said packet formed using said second data sequence delayed by an offset time to a second multicast group.   
     
     
         6 . The apparatus according to  claim 5 , wherein said second data sequence is a parity packet.