Research And Implementation Of Mobile Management Using Diameter In The High-speed Wireless Internet

It is the all-IP mobile communication system that will be the next generation of mobile communication system, whose mobility management is consisted of two supporting protocols :mobile PPP and mobile IP; meanwhile, mobility management is recognized as one of the most important issues and challenging in wireless IP networks.Considering the integration of different types of network and the rapid development of Internet, a new technology based on IP is urgently needed. Therefore, IETF advanced Diameter protocol which will replace Radius and become the new AAA protocol. Mobile IP, which was proposed by IETF, with its far and wide prospect in application is expected to be a promising solution in the future mobile communication systems and consequently a replacement of the various mobility management protocols in the existing mobile communication systems nowadays. But, mobile IP technology has some built-in weaknesses. For instance, it fails to guarantee the QoS (Quality of Service) of ongoing sessions in handoffs; it may cause unacceptable latency in location registration. And present researches are inclined to adopt a hierarchical mobility management approach to solve these problems, i.e. making use of the Mobile IP to support macro-mobility, and the optimized micro-mobility protocols to manage local area mobility.Based on the research existing outcomes, this paper promotes an approach of mobility management in an all-IP cellular mobile communication system platform. The two critical supporting protocols are included in this approach: one is the special MPPP (Mobile Point-to-Point Protocol) protocol, and the other is the Mobile IP protocol. Diameter is implemented based on the two protocols. Besides conforming to the standards already existed, both of the protocols have been added to some features particularly for the wireless IP networks. The function of mobility management is introduced into the MPPP protocol, which can support PPP handoffs of mobile subscribers. By using the scheme of tunnel, the MPPP protocol provides soft handoff in Data Link Layer and significantly supports local area mobility. Backed up by the MPPP protocol, the Mobile IP protocol can offer fast and smooth handoff, which applies the concept of post-registration handoff and leads to no packet loss and low latency in the handoffs. More details on the implementation and performance simulation are elaborated in my thesis. It has been proved by the sufficient results of simulation that this approach is practicable, especially for its contribution in fastness and smoothness of handoff, which is considered to be an innovation and indicates the benefit of Diameter.