Cooperative Relay Multicast Technology in Cellular Mobile System and Algorithm Design for Multicast Tree

Multicast application is one of key value-add field to cellular mobile network. Most of researches focus on the whole system and ignore the structure inner cell. Current structure must let the signal strength satisfy the request of terminals located on the edge of cell, and this influence the capacity and data rate of multicast in same cell. we propose a cooperative relay multicast structure for cellular mobile system. In this paper, we first illustrate the principle of this structure. And then we focus on the algorithm of minimum-cost and minimum-power QoS multicast tree for relay nodes. Because our algorithm need optimize multiple factor, Current algorithm can not fit this network. Because of great many studies on minimum-cost delay constrained Steiner minimum tree (SMT) in past literature, we can get a minimum-cost QoS SMT first. And then we get a Minimum Spanning Tree (MST) by set power as weight of edges. At last, we choose constants optimize method to get an algorithm to compute approximately minimum-cost and power QoS multicast tree. Simulation result show this algorithm can get expected goal.