A SIP-based Method for Intra-Domain Handoffs

The mobility management issue in IP access networks can be dealt with from various perspectives. A possible approach includes the use of the Session Initiation Protocol (SIP) and its associate entities for mobility signaling. Following this approach, existing SIP functionality in a network can be reused for mobility management purposes, providing efficient utilization of resources. In this paper we propose the Hierarchical Mobile SIP (HMSIP) framework, a SIP-based intra-domain mobility management approach that builds upon the general framework of SIP mobility management. The HMSIP Agent is introduced as a border network entity providing the necessary mobility functionality. Detailed location and mobility management procedures are presented. The scheme is further enhanced with additional functionality for the support of multiple HMSIP Agents across the border of a domain, maintaining a unique contact address throughout a session within the domain.