Evaluation of the impact of mobility models on handover in WLAN indoor environments

Nowadays, mobility models are used to simulate realistic movements produced by the users of a wireless or a mobile network. The aim of this project is to evaluate the impact of mobility models on handover process in Wireless Local Area Networks (WLAN) indoor environments, using the network simulator NS-2. This document contains a previous theoretical characterization of the basic mobility models and their application in the network simulator NS-2, a study of the infrastructure mode support and a modification of the current handover algorithm. The study focuses on two mobility models in WLAN indoor environments: one where movements are completely random (i.e. Random Waypoint) and another one where next step depends on previous movements (i.e. Gauss-Markov). In order to support infrastructure mode operation in WLAN, a new patch with modifications of the source code is applied. Furthermore, a first approach for the development of a new handover algorithm is presented. Simulations are run in two different scenarios: one with 4 Access Points (APs) offering full coverage in the simulated area, and another one with 8 APs, simulating overcoverage in order to guarantee higher capacity for a higher density of users. Results are presented showing a comparative of the cell residence time (CRT) for each scenario. From the results obtained, it is possible to see that the CRT changes depending on the algorithm and the mobility model applied, being lower when the Random Waypoint model is applied. On the other hand, the new handover algorithm designed from the current implementation leads to a decrease in the average CRT