Research On Mobility Management For Next Generation Network

To provide wide communication services, the NGN (Next Generation Network) needs to converge many different access networks, and thereby it can meet the mobile users' individual and diversified requirements. So one of the characteristics of NGN is diversity of access. Namely, the communication environment is heterogeneous and the access is asymmetrical. Because of the difference of heterogeneous networks architecture and the diversity of requirements of mobility management, every kind of access network adopts different mobility management technology. It causes the result that subscribers can roam in homogeneous network but cannot move across heterogeneous networks. The NGN wants to converge the heterogeneous networks to support mobile computing and ubiquitous computing, and the open and efficient generalized mobility management is one of the key technologies.This dissertation mainly makes scientific researches on mobility management in three aspects: mobility management scheme based on multiprotocol, generalized location management within multisystem, and vertical handoff among heterogeneous networks.As for the mobility management scheme based on multiprotocol, this dissertation first proposes a mobility management scheme based on SIP and MIPv6. Next, the MA (Mobility Agent) is adopted to improve this scheme. Meanwhile, considering the impact of link handoff, it further advances an improved scheme based on link layer. And then this dissertation brings forward a whole new scheme with the HIP draft submitted by IETF. Moreover, it designs an improved scheme based on the expansion of HIP protocol.As far as the generalized location management within multisystem is concerned, this dissertation first puts forward the hierarchical LA (Location Area) scheme and tridimensional LA scheme. When synthesizing the merits of the two schemes, this dissertation designs the hierarchical tridimensional LA scheme. For the scheme, this dissertation has formed a basic strategy for generalized location management, and then provides the multilevel pointer forwarding strategy to optimize the system performance. Apart from that, it proposes the improved strategy on the basis of the fuzzy location area boundaries. Finally, a generalized IP address management scheme to manage the multiaddress for multimode MN is put forward here. For the vertical handoff among heterogeneous networks, this dissertation first discusses the scenarios of vertical handoff. Then it brings forward the vertical handoff strategy for MN and the corresponding strategy for CN. Further more, this dissertation advances the vertical handoff algorithm based on AHP method. In the end, a vertical handoff protocol based on the expansion of MIH draft is designed and an application demonstration is shown.