Solutions for mobility support in DHCP-based environments

In a wireless mobile scenario it is very important for IP terminals to automatically reconfigure themselves when moving amongst different access networks. Each time that a terminal changes its point of attachment it should rapidly detect new access network, acquire a new IP configuration, according to the new network, and opportunely reconfigure itself. During this operation crucial aspects are the latency of the overall procedure, the processor and packet load, the scalability, the independence from the access technique (WLAN, GPRS, others), and the compatibility with the current implementations of terminal mobility/nomadicity. In this work the problem of roaming amongst IP-based access network is considered and the issues of subnet detection and terminal configuration are focused. Particularly, we propose and describe in detail some solutions that are based on a simple extension of the largely implemented DHCP protocol. The proposed mechanisms are very light, scalable, and could be compatible with current implementations.