Smooth Handoff in Mobile IP

With the increasing popularity of devices such as mobile phones and PDAs, there is a higher demand for wireless access to the Internet. Mobile IP was proposed to provide such access. This report gives a brief introduction and some background to Mobile IP and then focuses on handoffs (i.e. when the mobile node moves from one base station to another) in Mobile IP and especially on how to eliminate the loss of packets during such a handoff. In particular, this report focuses on handoffs when dealing with real time applications such as voice traffic where there is an upper limit on the delay between incoming packets before the quality of the session becomes unacceptably poor. We propose a solution for how to eliminate the loss of packets and we compare it to other existing solutions. The proposed solution is to have buffers at every base station (foreign agent) where all the incoming packets are saved. If the mobile node moves to another foreign agent, the packets in the buffer for that mobile node will be sent to its new foreign agent where they are delivered to the mobile node. Thus, the packets will not be lost. We will analyze and compare different buffering management solutions to get the best result. Also, the performance of this proposed solution is analyzed during a handoff to verify that its delay does not exceed the above-mentioned upper limit