An SIP-Based Location Management Framework in Opportunistic WiFi Networks

In this paper, we propose a novel session-initiation-protocol-based location management framework in opportunistic WiFi networks. In the proposed framework, a mobile terminal needs to update its attachment to the network only when it connects to a new WiFi access point to reduce its location update traffic. In addition, to find out the exact point of attachment, a timer-based session setup procedure is introduced, which can intelligently reduce the session setup latency by looking for a user in either WiFi or cellular systems. We develop analytical models for the location update cost and the session setup latency and investigate the optimization of the timer under the realistic WiFi hotspot residence time model.