Method and apparatus for improved multicast streaming in wireless networks

Abstract

The invention includes a method and apparatus for providing media content. The method includes duplicating each packet of an original packet stream for which an associated importance level satisfies an importance condition, inserting each duplicate packet within the original packet stream to form thereby a modified packet stream, and transmitting the modified packet stream toward a wireless terminal adapted for processing the modified packet stream for presenting the media content conveyed by the original packet stream. The duplicate packets may be inserted within respective windows associated with the duplicate packets, wherein each window is determined according to an original packet position associated with the original packet from which the duplicate packet is formed.

1 . A method for presenting media content at a mobile node using a presentation stream, comprising:
 receiving a data packet stream comprising a plurality of data packets, wherein the plurality of data packets comprises a duplicate data packet, wherein the duplicate data packet is a duplicate of an original data packet having an importance level satisfying an importance condition; and   generating the presentation stream using data packets of the data packet stream, wherein generating the presentation stream comprises:
 when the original data packet is included within the data packet stream and is not corrupted, using the original data packet for generating the presentation stream while ignoring the duplicate packet; 
 when the original data packet is missing from the data packet stream or is included within the data packet stream but is corrupted, using the duplicate data packet for generating the presentation stream. 
   
   
   
       2 . The method of  claim 1 , wherein, for each data packet, the importance level of the data packet is based on at least one header parameter of the data packet. 
   
   
       3 . The method of  claim 2 , wherein the at least one header parameter comprises one of:
 a value of a random access point (RAP) flag field where the data packet includes an MPEG frame; or   a value of a network abstraction layer (NAL) reference indicator (NRI) field where the data packet includes an H.264 frame.   
   
   
       4 . The method of  claim 1 , wherein the duplicate data packet is transporting an I-frame. 
   
   
       5 . The method of  claim 1 , wherein each data packet has a sequence number associated therewith, wherein the sequence number of the original data packet and the sequence number of the duplicate data packet are identical. 
   
   
       6 . The method of  claim 5 , wherein generating the presentation stream further comprises:
 processing the data packets of the data packet stream according to a packet order determined according to the sequence numbers of the data packets;   
   
   
       7 . The method of  claim 6 , wherein processing the duplicate data packet for inclusion in the presentation stream in place of the original data packet comprises:
 identifying the duplicate data packet using the sequence number of the duplicate data packets; and   accessing the duplicate data packet for use in generating the presentation stream.   
   
   
       8 . The method of  claim 1 , further comprising:
 propagating the presentation stream toward at least one interface of the mobile node.   
   
   
       9 . The method of  claim 8 , further comprising:
 presenting the media content conveyed by the presentation stream using the at least one interface of the mobile node.   
   
   
       10 . A mobile node for presenting media content using a presentation stream, the mobile node comprising:
 means for receiving a data packet stream comprising a plurality of data packets, wherein the plurality of data packets comprises a duplicate data packet, wherein the duplicate data packet is a duplicate of an original data packet having an importance level satisfying an importance condition; and   means for generating the presentation stream using data packets of the data packet stream, wherein generating the presentation stream comprises:
 when the original data packet is included within the data packet stream and is not corrupted, using the original data packet for generating the presentation stream while ignoring the duplicate packet; 
 when the original data packet is missing from the data packet stream or is included within the data packet stream but is corrupted, using the duplicate data packet for generating the presentation stream. 
   
   
   
       11 . A method for presenting media content at a mobile node using a presentation stream, comprising:
 receiving a data packet stream comprising a plurality of data packets, wherein the plurality of data packets comprises an important data packet having an importance level satisfying an importance condition;   receiving an error correction packet stream comprising a plurality of error correction packets, each of the error correction packets associated with at least one data packet of the data packet stream, wherein each error correction packet has at least a first error correction level associated therewith, wherein one of the error correction packets associated with the important data packet has a second error correction level associated therewith, wherein the second error correction level is greater than the first error correction level; and   processing the data packet stream for generating the presentation stream, wherein the error correction packets of the error correction packet stream are adapted for use in correcting errors in data packets of the data packet stream.   
   
   
       12 . The method of  claim 11 , wherein, for each data packet, the importance level of the data packet is based on at least one header parameter of the data packet. 
   
   
       13 . The method of  claim 12 , wherein the at least one header parameter comprises one of:
 a value of a random access point (RAP) flag field where the data packet includes an MPEG frame; or   a value of a network abstraction layer (NAL) reference indicator (NRI) field where the data packet includes an H.264 frame.   
   
   
       14 . The method of  claim 11 , wherein the important data packet is transporting an I-frame. 
   
   
       15 . The method of  claim 11 , wherein the one of the error correction packets associated with the important data packet comprises an error correction parameter, wherein the error correction parameter satisfies the second error correction level. 
   
   
       16 . The method of  claim 15 , wherein the error correction parameter is computed using information from the associated important data packet. 
   
   
       17 . The method of  claim 15 , wherein the error correction parameter is computed using:
 information from the associated important data packet; and   information from at least one data packet, of the data packet stream, that is adjacent to the important data packet.   
   
   
       18 . The method of  claim 11 , wherein processing the data packet stream for generating the presentation stream comprises:
 identifying an error associated with one of the data packets of the data packet stream;   identifying one of the error correction packets associated with the one of the data packets for which the error is identified; and   correcting the one of the data packets for which the error is identified using the identified one of the error correction packets.   
   
   
       19 . The method of  claim 18 , wherein the error is associated with the important data packet, wherein the identified one of the error correction packets is the one of the error correction packets associated with the important data packet. 
   
   
       20 . A mobile node for presenting media content using a presentation stream, the mobile node comprising:
 means for receiving a data packet stream comprising a plurality of data packets, wherein the plurality of data packets comprises an important data packet having an importance level satisfying an importance condition;   means for receiving an error correction packet stream comprising a plurality of error correction packets, each of the error correction packets associated with at least one data packet of the data packet stream, wherein each error correction packet has at least a first error correction level associated therewith, wherein one of the error correction packets associated with the important data packet has a second error correction level associated therewith, wherein the second error correction level is greater than the first error correction level; and   means for processing the data packet stream for generating the presentation stream, wherein the error correction packets of the error correction packet stream are adapted for use in correcting errors in data packets of the data packet stream.