עמוס ביימל

An erasure correcting scheme is rateless if it is designed to tolerate any pattern of packet loss and reveal the transmitted information after a certain number of packets is received. On the one hand, transmission schemes that use rateless erasure correcting schemes do not usually use a feedback channel. However, they may require significant amount of additional processing by both the sender and the receiver. On the other hand, automatic repeated request protocols use a feedback channel to assist the sender, and do not usually require information processing. In this work we present a combined approach, where a lean feedback channel is used to assist the sender to efficiently transmit the information. Our Real-Time oblivious approach minimizes the processing time and memory requirements of the receiver and, therefore, fits a variety of receiving devices. In addition, the transmission is real-time where the expected number of original packets revealed when a packet is received is approximately the same throughout the entire transmission process. We use our end-to-end scheme as a base for broadcast (and multicast) schemes. An overlay tree structure is used to convey the information to a large number of receivers. Moreover, the receivers may download the information from a number of senders or even migrate from one sender to another.