Prioritized retransmission of internet protocol television (IPTV) packets

摘要

A method and system for improved error resiliency in Internet protocol Television (IPTV) are provided. Received media stream is encoded in a real-time protocol. The RTP media stream is then reordered in a homogeneous arrangement (e.g., video packets together, audio packets together) such that each RTP packet, which contains video contains data from a single video frame. Furthermore, each RTP packet contains a RTP header extension, which specifies the priority of the data. Audio frame and intra-coded frames (I-frames) are marked as highest priority frames, predictably coded frames (P-frames) are marked as high priority frames, bidirectionally coded frames (B-frames) are marked as lower priority frames with anything else occupying the lowest priority. The media stream is forwarded to the plurality of users, in accordance with the priority of each packet. A subscriber's device requests retransmission of any missing packets.

主权项

1. A method for improving error resilience in Internet Protocol multimedia communication, comprising:
receiving a multimedia stream at a retransmission (RET) server configured to store for retransmission a plurality of packets forming a most recent portion of the multimedia stream; and forwarding, toward a device associated with a retransmission request, only retransmission packets able to be timely processed by said device as indicated by a time stamp included within said retransmission request of a packet being processed by said device; wherein a time that a packet[k] may be forwarded to said device is expressed by the equation:
t[k]=treq+u[k]−uout−TRT where:
freq is the time the RET server receives a request for retransmission;u[k]−uout is the latest a packet with a sequence number s[k] must arrive at the device after device transmission of the request;TRT is a round trip packet travel time between the device and RET server.