For Dynamic Multicast Network Coding Algorithm

Network coding is an information exchange technology which combines routing and coding. The main principle behind network coding is that the relay(intermediate) nodes in the communication network make encoding and decoding operations to the data bits.Although many algorithms and models about network coding improving the throughout of multicast are proposed, most of them are not practical in Internet environment, the reasons are: (1) coding algorithms are required to flood the whole network, that is to say, the nodes in the network in addition to the source node and sink nodes are all involved in coding, the cost brought by network coding is very large; (2) present models are not suitable for group membership dynamic and heterogeneous networks. So this paper proposes network coding algorithms for dynamic multicast which include two parts: Network Coding for Dynamic Multicast in Unit Capacity Network (NCDMUCN) and Network Coding for Dynamic Multicast in Heterogeneous Network (NCDMHN). They both support group members joining or leaving group any time, and can increase the average throughput of the multicast group significantly, so the throughput from source to every group member is the maximum flow of the multicast group; realize the algorithms in NS2; evaluate the algorithms'performance, the results present the algorithms not only enable all the group members'throughout achieve the maximum throughout of the multicast group, while the coding cost is also very low.