High Mobility in a Realistic Wireless Environment: a Mobile IP Handoff Model for NS-2

Wireless technology has the great merit to allow users' mobility. However, this may affect the functioning of all the applications and traditional protocols, worsening the already known problems with wireless connections and requiring the design and evaluation of novel solutions. Scenarios involving high mobility can be very complex; think, for instance, to a realistic case involving several nodes, representing people and cars moving under the coverage of several base stations. Since the geographical width and the number of involved nodes in such a scenario, simulations represent a fundamental tool to analyze the state of the art and newly proposed solutions. Unfortunately, modeling mobility with the most popular network simulator in the scientific community (i.e., NS-2) is not an easy task as its handoff mechanism appears faulty when coupled with a realistic model for wireless transmissions. In this paper, we discuss this problem and propose a new simulation module for Mobile IP able to guarantee smooth handoffs even with realistic simulation set-ups.