卫星Internet中一种QoS组播路由机制

A QoS Multicast Routing Scheme in Satellite-Based Internet

考虑了卫星Internet拓扑变化的可预测性和组播应用的服务质量QoS(quality of service)需求,设计了一种QoS组播路由机制.给出了卫星Internet中QoS组播路由问题模型及其数学描述,引入拉格朗日松弛,设定适应度函数,使用PRIM算法,基于次梯度优化,寻找生存周期最大化的QoS组播路由树.基于NS2进行了仿真实现和性能评价.仿真结果表明,同传统的组播路由机制相比,该机制是可行和有效的,提高了QoS组播路由树生存周期,具有良好的性能.

Considering the predictability of topology dynamics of satellite-based Internet and QoS （quality of service） requirement of group applications, a QoS multicast routing scheme is presented. The corresponding model and its mathematical description of the QoS multicast routing problem in satellite-based Internet are given with the Lagrange relaxation introduced in to set the fitness function so as to seek a QoS multicast tree with the maximum life cycle by the PRIM algorithm, based on the sub-gradient optimization. The proposed scheme is implemented by simulation on the basis of NS2 with its performance evaluated. Simulation results showed that the proposed scheme is both feasible and effective with prolonged life cycle of QoS multicast routing tree and improved performance in comparison with the conventional one.