Performance analysis of optimized smooth handoff in mobile IP

Abstract

Mobile IP allows node mobility involving changes of point-of-attachment to the Internet. In order to reduce the impact on the performance and the signaling overhead, hierarchical mobility management schemes have been introduced. These schemes define protocols that allow movements within a domain to be handled locally, without involvement of the mobile node's home network. In order to reduce more the packet losses during handoff, new schemes have been defined, such as smooth handoff. By storing packets temporarily in the access point after the mobile host has left and forwarding them to the new access point as soon as the mobile has connected to it, it is possible to reduce significantly the packet loss. In this paper we develop an analytical model and a simulation program using OPNET Modeler to evaluate the packet loss and packet delay for UDP streams and the throughput for TCP streams that are involved in a handoff. We show that, in spite of the buffering capabilities of the previous access point, packets may still get lost. The reason for this loss is identified and solutions to this problem are proposed.