Evaluating the Performance Boundaries of Wi-Fi, WiMAX and UMTS using the Network Simulator (ns-2)

Currently, the different wireless technologies available allow users to access the Internet under the "always on" paradigm. Therefore, switching from one wireless technology to another, a process known as vertical handover, is often required. It is very important for vertical handover agents to know the performance of each candidate wireless network in order to switch into a network that fulfills the applications' requirements. In this work we present a performance evaluation of the main wireless technologies currently in use by mobile devices: Wi-Fi, WiMAX and UMTS. In our set of experiments we tested various schemes with different parameters for each technology, including modulation and channel bandwidth. Using the Network Simulator (ns-2), we evaluate the performance of each network technology under different network congestion conditions. Results show that each technology offers different data rates, depending on the selected parameters. Moreover, we found that bandwidth availability status becomes of utmost importance for successful vertical handover.