【摘要】 提出在基于范围的移动组播协议(RBMo M)的基础上根据用户的移动特性、业务量及网络特性为每个主机动态地确定最优服务范围的算法,形成了基于动态范围的移动组播协议(DRBMo M).该协议通过设计一个代价函数并求解使代价函数最小化的服务范围来实现减小组播分组传输时延和组播树重构频率的折衷.分析表明,代价函数值随主机的业务量和移动速度的增加而增加;最优服务范围随主机业务量的增加而减小,随主机移动速度的增加而增加.在性能对比中发现,DRBMo M的代价函数值小于RBMo M的代价函数值,表明DRBMo M的确增强了RBMo M的性能;在与同类方案的比较中,发现DRBMo M的平均切换信令代价稍高于同类方案,但其平均组播分组传输代价及最终的代价函数值均小于同类方案.更多还原

【Abstract】 A protocol named Dynamic Range-Based Mobile Multicast(DRBMoM)is proposed, which designs an algorithm based on Range-Based Mobile Multicast(RBMoM)to dynamically determine an optimal service range for each Mobile Host according to its mobility characteristics, service traffic and some network parameters. DRBMoM trades off between the shorter multicast delivery path and the fewer multicast tree reconstruction frequency by designing a cost function and searching the service range minimizing the cost function. Analyses are carried out to show that the cost function value increases with the increase of user’s service traffic and mobility rate; While the optimal service range decreases with the increase of user’s service traffic and increases with the increase of user’s mobility rate. In addition, the cost function value of DRBMoM is smaller than that of RBMoM, which means DRBMoM outperforms RBMoM. At last, analyses show that the average handoff signaling cost of DRBMoM is appreciably higher than that of the congeneric scheme, while the average multicast packet transmission cost and the cost function value of DRBMoM are all lower than those of the the congeneric scheme.更多还原