On dynamic load distribution algorithms for multi-AP WLAN under diverse conditions

Future wireless networks will enjoy ubiquitous connectivity by taking advantage of the IP core convergence which is seen as the lingua franca of heterogeneous access networks ecosystem. It is expected that the prevalence of WLAN and the advent of IEEE 802.11n standard will continue to offer compelling opportunities and therefore be considered as one of the de-facto wireless access network. However, it is known that wireless network conditions in general are diverse owing to both traffic and wireless channel variations. This raises the importance of exploiting diversity across a multiple access points (multi-AP) WLAN, which requires an advanced network control mechanism to effectuate uniform load distribution, so that QoS of users and composite capacity can be improved. Although various load distribution algorithms for WLAN have been investigated in literature, there is a lack of performance comparison between different algorithms. In this paper, we present a comparison of three dynamic load distribution algorithms, viz. predictive load balancing (PLB), predictive QoS balancing (PQB) and reactive QoS balancing (RQB) for infrastructure-based WLAN with DCF access mechanism based on OPNET simulations.