Cell Breathing Based on Supply-Demand Model in Overlapping WLAN Cells

Introducing cell breathing in cellular networks into wireless local area networks (WLANs) for load balancing is beneficial since no special modification of clients. However, fairness and effectiveness is quite challenging in cell breathing. In this paper, a supply-demand model (SDM) based on cell breathing technique is proposed to allocate continuous or discrete power to APs for fair and effective load balancing. SDM classifies the beacon power of an AP into two kinds: the demand power and the supply power. The former is the ideal power that an AP is supposed to have while the latter is the power the AP actually transmits. Finding the deterministic global optimal solution, SDM makes the demand and supply power as equal as possible and the load on APs balanced. Because SDM does not need multiple iterations to compute the optimum, it can avoid frequent user handoffs resulting from frequent power change. Finally, SDM is extended to support a broader range of load definition and the generalized relationship between beacon power and load. The simulation results show the proposed scheme is fair for realizing load balancing and effective for improving throughput.