Hierarchical Qos Multi-path Multicast Routing Protocols In A Mobile Internet

Mobile Internet is a dream for people to access Internet anytime and anywhere. With the convergence of traditional Internet and wireless communications, such a dream is becoming true. A large number of mobile devices keep connections with mobile Internet and their QoS(Quality of Service) is expected to be guaranteed as in traditional wired Internet. These potential commercial requirements are bringing more opportunities to the development of mobile Internet, at the same time more challenging issues are ahead of us to guarantee QoS in mobile Internet.This paper proposes a QoS-aware Hierarchical Multi-path Multicast routing protocol (QoSHMM). It establishes a QoSHMM multicast tree by the principle of "ring in the same tier of the hierarchy and tree in different tiers". It forms one shortest-delay path and multiple paths with delay-constrained minimal-cost. We obey the principle of forming "the largest ring" to make more nodes to be added into the group even if no real multicast data are transmitted. Therefore, in case of hand-off, mobile host can be served in time without reconstructing the multicast tree just like some predictive mechanisms. Furthermore, the proposed protocol runs in a parallel and distributed way in the sense that all the paths are established with local information only. QoSHMM shows a good performance at average handoff delays from the simulation results. By adopting a novel reservation mechanism with three states, this protocol shows high fault tolerance property.