Load control scheme at local mobility agent in mobile IPv6 networks

In IP-based mobile networks, a few of mobility agents (e.g., home agent and foreign agent) are used to support seamless mobility. In terms of network performance, scalability at these agents is one of the most important issues in mobile networks. In Hierarchical Mobile IPv6 (HMIPv6), a new mobility agent, called mobility anchor point (MAP), is deployed in order to handle binding update procedures locally. However, the MAP can be a single point of performance bottleneck when there are a lot of local movements. This is because the MAP handles signaling traffic as well as data tunneling traffic. Therefore, it is required to limit the number of mobile nodes serviced by a single MAP to provide a certain quality of services with mobile users. In this paper, we propose a load control scheme at the MAP utilizing admission control algorithms. In terms of admission control, we use cutoff priority scheme and new session bounding scheme. For the purpose of performance evaluation, we develop Markov chain models for two admission control algorithms and evaluate on-going MN dropping and new MN blocking probabilities. As a result, the proposed load control scheme can reduce the blocking probability and provide more satisfied services with users.