【作者】 汪静；

【导师】 王能；

【作者基本信息】 华东师范大学 ， 系统分析与集成， 2008， 博士

【摘要】 为了提供自由广阔的通信服务环境,下一代网络需要将多种接入网络有效融合以实现不同接入技术的优势互补,从而满足移动用户个性化、多样化的通信业务需求。因此,下一代网络的重要特征之一就是接入的多元性,即“通信环境是异质的”、“接入是非对称的”。但由于各异质网络体系结构的差异性和移动性管理需求的多样性,不同的接入网络采用了不同的移动性管理技术,这导致用户在结构相同的接入网中可以漫游,而在结构不同的接入网间移动则受到很大限制。也就是说,目前只能在同质网络环境中提供移动性支持,还无法提供跨网的通用移动性支持。下一代网络要实现泛在的、协同的移动计算和普适计算,就需要有效融合各异质网络以保证在不同网络间的无缝移动,而开放的、高效的、与接入技术无关的通用移动性管理技术则是其核心问题之一。本文主要从基于多协议的移动性管理模型、多系统中的通用位置管理、异质网络间的垂直切换三个方面对移动性管理技术作了如下研究:在基于多协议的移动性管理模型中,本文首先提出了一个基于现有网络协议SIP和MIPv6联合优化的移动性管理模型,并在该模型基础上引入移动代理进行改进,同时考虑到链路切换的影响,又进一步提出了基于链路层移动性管理的改进模型。然后,本文结合IETF所提交的HIP协议草案设计了一整套全新的适于单模和多模移动节点的、可应用于同质和异质网络的移动性管理模型,并通过对HIP协议的功能扩展提出改进模型。本文所提出的这一整套移动性管理模型在不增加网络基础设施复杂性的情况下,可提供跨同质网络或异质网络的无缝移动性支持。在多系统中的通用位置管理方面,本文首先提出层次型位置区和立体式位置区的设计方法,并在综合两者优点的基础上,进一步提出层次型立体式位置区的设计方法。然后,针对该位置区设计,本文给出基本的通用位置管理策略,并从系统性能优化的角度提出基于阈值的动态多级指针转发的改进策略和相应的位置更新算法、位置寻呼算法,再进一步从改善位置区边界微移动性能的角度提出基于位置区边界模糊的改进策略和算法。最后,本文针对多模移动节点中多IP地址的管理提出多接入下的地址管理方案。本文所提出的通用位置管理方案、策略和算法在满足不同类型用户接入要求的情况下,可有效降低系统的位置管理开销,改善越区切换性能。在异质网络间垂直切换方面,本文首先探讨了垂直切换的应用场景。然后,利用本文对HIP协议的功能扩展分别提出在不同接入状态下移动节点的上行垂直切换策略和下行垂直切换策略以及对端通信节点应对策略。接着,本文在基于接收信号强度的垂直切换算法基础上提出基于网络属性映射函数的改进算法,并进一步从多属性(准则)切换决策的角度提出基于AHP的垂直切换算法。最后,本文结合IEEE所提交的MIH协议草案并通过对其功能扩展设计出垂直切换协议,并给出该协议应用示例。本文所提出的垂直切换策略、算法和垂直切换协议可根据移动节点的接入状态、移动状态和业务需求等多重因素提供智能的垂直切换支持。更多还原

【Abstract】 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.更多还原