A 2-D Random Walk Mobility Model for WiMAX Location Update

Mobile Worldwide Interoperability for Microwave Access (WiMAX) network is increasingly popular, and upcoming deployments can be expected with the development of intelligent transport systems (ITS) and the advent of smart cities. However, both applications will demand an efficient management of high mobility. Therefore, optimizing the cost of mobility signaling procedures of the network is key. In this work we study the location update procedure in WiMAX networks. Whilst previous works consider 1-D layouts of base stations (BSs), corresponding to ITS-based scenarios, we focus on extending that scenario to develop an analytical model for 2-D layouts, which fit better for cities. Our model consider the two cases in which the logical entity in charge of handling the location tracking and paging operations, known as anchor paging controller (APC), is assigned for a mobile station (MS) during a location update: when the old APC is reassigned (no relocation), and when a new APC is assigned (relocation). The comparison is made by calculating the cost (as the number of exchanged messages) of the location update procedure in each case. We validate our model through simulations, and discuss the impact on the final cost of several parameters, such as type and frequency of the movements. Finally, we provide some guidelines on how to assign the APC depending on the network parameters