US 2010/0146357 A1 · RELIABLE MULTICAST WITH LINEARLY INDEPENDEDNT DATA PACKET CODING

Abstract

Regular data packets are scheduled for transmission from a sender to multiple receivers in a multicast ARQ system. In a joint scheduling and encoding procedure, a composite data packet is formed as a weighted linear combination of regular data packets. The corresponding coding weights are adapted based on feedback information from the receivers about received data packets such the composite packet represents a new linearly independent coding of regular data packets different from any multicast data packet previously received each receiver in a selected set of the receivers during the multicast session. In addition, using a weight vector with at least two different non-zero coding weights adds a further degree of freedom and guarantees the ability to always form a composite data packet that represents a new linearly independent coding for transmission. The ability to transmit linearly independent data packets in at least a majority of the transmission instances will significantly improve the throughput performance for reliable multicasting, especially when the number of users is large.

Claims31

Dependent claims

A method of scheduling and encoding data packets for transmission in a multicast session from a sender to at least two receivers in a multicast ARQ (Automatic Repeat reQuest) communication system, wherein the following steps are performed at each of a plurality of scheduling instances:

obtaining feedback information from said at least two receivers indicating received data packets;
forming at least one composite data packet as a weighted linear combination of regular data packets based on a corresponding weight vector comprising a set of coding weights;
adapting, for each of said at least one composite data packet, said coding weights of said weight vector based on said feedback information such that the composite packet represents a linear combination of regular data packets that is linearly independent, for each receiver of at least a set of said receivers, of any data packet previously received by the receiver during said multicast session;
said sender transmitting said at least one composite data packet to said at least two receivers.

1 more element

An arrangement for scheduling and encoding data packets for transmission in a multicast session from a sender to at least two receivers in a multicast ARQ (Automatic Repeat reQuest) communication system, wherein said arrangement is configured for executing the following operational procedure at each of a plurality of instances:

obtaining feedback information from said at least two receivers indicating received data packets;
forming at least one composite data packet as a weighted linear combination of regular data packets based on a corresponding weight vector comprising a set of coding weights;
adapting, for each of said at least one composite data packet, said coding weights of said weight vector based on said feedback information such that the composite packet represents a linear combination of regular data packets that is linearly independent, for each receiver of at least a set of said receivers, of any data packet previously received by the receiver during said multicast session;
transmitting said at least one composite data packet to said at least two receivers.

1 more element

Dependencies are inferred from the claim text.

Reliable multicast with linearly independednt data packet coding

Life of this patent

Reliable multicast with linearly independednt data packet coding

Life of this patent

Abstract

Claims31