System and method for handling critical packets loss in multi-hop RTP streaming

摘要

Disclosed are example embodiments of a method and system to reduce re-transmission requirements of a compress media transferring system implemented in a network where packet loss could be possible. An extended header for each transmitted packet can indicate the priority of the packet and endpoints can determine if a re-transmission of a missing packet is desired. Buffering of packets at different hops in a multi-hop system could allow for the retransmission request to be satisfied by a more recent hop than the original system transmitting the video packet. In one embodiment three levels of priority are established to achieve a reliable frame rate of 30 frames per second by compressing the first and second levels at 7.5 frames per second and a third level at 15 frames per second.

主权项

1. A method comprising:
obtaining a stream of a plurality of transport protocol (TP) packets at a media transmitting device, the stream of the plurality of TP packets carrying compressed media data-units that were created by a scalable coding (SC) encoder, each of the plurality of TP packets having an assigned priority level, wherein the stream of the plurality of TP packets comprises at least one packet of a first priority level and at least one packet of a second priority level; assigning a first sequence number to a first header field of a plurality of header fields for each of the plurality of TP packets, wherein the first sequence number is changed for each TP packet of the first priority level; and transmitting the plurality of TP packets toward one or more media receiving devices; wherein the media transmitting device is an intermediate node between an originating media transmitting device and a final media receiving device; wherein the first sequence number is replaced for each TP packet of the first priority level by each intermediate node along the path of the stream; wherein the first sequence number is usable by a first media receiving device, selected from the one or more media receiving devices, to identify one or more missing TP packets that got lost in a network segment between the media transmitting device and the first media receiving device and to request retransmission of missing TP packets from the media transmitting device; and wherein each first priority TP packet reflects compressed video data of frames of a base layer; and wherein the media transmitting device or the one or more media receiving devices comprise a multipoint control unit (MCU), a media relay multipoint control unit (MRM), a media gateway, or a media-hop.