Hierarchical Scanning Algorithm for Integrated Mobile and Nomadic Access Systems

In next generation wireless networks, not only wide area cells to provide moderate data rate with full mobility but also local area cells to support high data rate with local mobility will be deployed. In addition, numerous local area cells may be located within the coverage of wide area cells to increase overall network capacity and offer high quality services. In this circumstance, a scanning operation to detect suitable local area cells for handoff can degrade the performance of a mobile station since repeated trials of scanning are likely to cause service disruption and considerable power consumption. To solve these problems, we propose a hierarchical scanning algorithm that enables the mobile station to obtain the neighbor cell information corresponding to its own situation. We present an analytical model for the proposed algorithm and evaluate its efficiency in terms of the time spent in the scanning operation. Simulation results show that the proposed algorithm requires much less time to detect suitable local area cells for handoff than a non-hierarchical scanning algorithm, which is conventionally used.