Network Discovery Mechanisms for Fast-handoff

Proactive handoff mechanisms involving secure pre-authentication and proactive configuration help reduce the delay and transient data loss for real-time communication during movement between homogeneous or heterogeneous access networks. Pre-authentication is meant to perform authentication with a network before a mobile moves into the network. To achieve secure pre- authentication with a target neighboring network, a mobile needs to obtain an IP address of the authentication server from the target network when the mobile is still outside the target network and then to establish a security association with the authentication agent in the target network. This requires the mobile to discover the parameters of various network elements in the target network ahead of time so that the mobile can communicate with these network elements to establish proactive security associations. We describe several approaches for a mobile to discover the network elements in target networks before moving into these target networks. We also describe how network discovery can help provide fast-handoff using secure pre-authentication and proactive IP address acquisition during handover between different access networks.