An Efficient Method of Mobile IP Based Handoff Mechanism for WLAN-GPRS Integrated Network

This paper proposes a new technique for Mobile IP (MIP) registration by WLAN Host (WH) of the Internet through GPRS network. The Home Agent (HA) of WH resides in the Internet. The gateway GPRS Support Node (GGSN) provides Foreign Agent (FA) functionality for WH in GPRS. After successful attachment with GPRS network in roaming scenario, WH needs two mandatory passes for MIP registration with HA. In first pass, it establishes PDP context in GPRS network and in second pass, it sends MIP registration request to FA at GGSN. This two-pass registration causes substantial delay for handoff from WLAN to GPRS. To minimize this delay, the authors propose a one-pass MIP registration technique through GPRS network by modifying the Activate-PDP-Context Request (APCR) message.