Collaborative Communication-based Reliable Multicast Loss Recovery Techniques. Ad Hoc Networks

Ad Hoc network is a kind of multi-hop wireless networks with the characteristics of infrastructureless, self-organizing, survivability strong, and fast networking. Multicast communication refers to that the data packets are sent from a single source to a group of recipients in a transmission. The use of multicast technology can increase the network and service providers'revenue, such as saving network transmission resources and reducing the point-to-point delay. However Ad Hoc network is different from wired networks, because of the characteristics of limited bandwidth and processing capacity, dynamic network topology and high transmission error rate. Therefore the technology of reliable multicast loss recovery in Ad Hoc network is challenge and interesting.Cooperative communication refers to that the different nodes in network share the reources with each other. In Ad Hoc networks node has limited transmission area, a pair of nodes which can not directly communicate with each other transmit packets with the help of other nodes'store and forward. In addition network coding technology is an important finding in the field of coding theory in recent years. Since it theoretically prove that if nodes are coded in an appropriate manner (for example, XOR), the network multicast traffic can always reach Shannon maximum flow minimum cut theorem under the cap. In Ad Hoc networks using network coding has become a research hotspot in recent years. However cooperative communication and network coding are separately researched in these works.This thesis focuses on the research of cooperative communication and network coding in Ad Hoc network reliable multicast loss recovery.1. In Ad Hoc network, every node experience different packet loss beacause of its location. So we intrduce cooperative communication into reliable multicast loss recovery, and propose an efficient approach called Cooperative Loss Recovery for Reliable Multicast (CoreRM). In CoreRM, a receiving node experiencing a packet loss tries to recover the lost packet through progressively cooperating with neighboring nodes, upstream nodes or even source node. CoreRM aims at recovering the data loss within minimal number of hops and latency, and seperating the loss recovery among the whole network to avoide generating bottleneck.2. Introducing network coding into cooperative reliable multicast loss recovery, we propose a novel approach named Cooperative Reliable Multicast Loss Recovery Based Network Coding (NecRM). NecRM use network coding at repair nodes which retransmit the loss packet. In this way the number of transmission can be shorten and network resource can be saved.In addition, both analytical and simulation results reveal that CoreRM improve the reliable multicast performance in terms of delivery ratio, throughput and point-to-point delay compared with UDP and Pragmatic General Multicast Protocol (PGM). In addition the comparing results of CoreRM and NecRM reveal that using network coding within loss recovery can improve the performance of reliable multicast more.