Patent ID: 7719978
Filing Date: 2010-05-18
Classification: H04L,H04N

Abstract:
1. A method for transmitting steaming scalably compressed media data over lossy packet-based communication networks, comprising the steps of: a) obtaining source data comprising independently encoded groups of elements; b) subjecting each element in a current group to primary channel coding with one from a family of channel codes, the channel code family being augmented to include a symbol corresponding to no transmission of the element; c) subjecting each element from a previously transmitted group to a secondary channel coding with one from a family of channel codes, the channel code family being augmented to include a symbol corresponding to no transmission of the element; and d) transmitting the source data over a sequence of transmission slots, each transmission slot comprising a time interval wherein, in each transmission slot, primary channel coded symbols from elements in the current group are transmitted together with secondary channel coded symbols from elements in the previously transmitted group; e) wherein the primary and secondary channel coded symbols transmitted within each transmission slot are arranged into network packets such that each transmission slot has its own set of network packets; f) wherein the primary and secondary channel coded symbols sent in each transmission slot are arranged within that slot's network packets following the Priority Encoding Transmission (PET) procedure; g) wherein information concerning lost packets which are not received by a receiver is ether received or inferred by the transmitter; h) wherein the information concerning lost packets which contain primary coded symbols from said previously transmitted group is used by the transmitter to select secondary channel codes for the elements of the previously transmitted group; and i) wherein the secondary channel coding of each element of the previously transmitted group is performed in a manner which takes advantage of the availability at the receiver of primary coded symbols from the previously transmitted group in packets which were successfully transmitted, so as to avoid or reduce redundant retransmission.