Algorithms for WLAN Coverage Planning

The impressive market spread of IEEE 802.11 based Wireless Local Area Networks (WLANs) is calling for quantitative approaches in the network planning procedure. It is common belief that such networks have the potentials to replace traditional indoor wired local networks and allow flexible access outdoor, eventually competing with classical cellular systems (GSM , GPRS, UMTS, etc.). The appropriate positioning of the Access Points (AP) is crucial to determine the network effectiveness. In a companion paper we argue that previously proposed approaches to coverage planning neglect the features of the IEEE 802.11 access mechanism, which limits system capacity when access points coverage areas overlap. In this paper we describe the optimization models with hyperbolic and quadratic objective functions that directly accounts for system capacity and we propose heuristics combining greedy and local search phases. Computational results show that our heuristics provide near-optimal solutions within a reasonable amount of time.