Dynamic load balancing techniques for flexible wireless industrial networks

This paper deals with load management in flexible industrial networks, characterized by a hybrid wired/wireless architecture and mobile wireless nodes. Our target scenario is an industrial network, in which data is exchanged between sensors and actuators running on the wireless side and a wired automation network. As many unpredictable elements affect the performance of wireless data transmission, it is necessary to control the load over the different Access Points (AP) through dynamic balancing policies. In traditional WLANs, one station selects the AP to connect with on the basis of the received signal strength indicator (RSSI). This approach may cause all active mobile stations to connect to a small subset of the APs and saturate their capacity, while other APs may still be underloaded. This paper shows a dynamic technique to manage the unbalanced load caused by moving nodes and fluctuating channel characteristics. Simulation results highlight the advantage of the proposed technique over the standard AP selection mechanism and another load balancing approach in the literature.