A Fuzzy Congestion Controller to Detect and Balance Congestion in Wsn

A Wireless Sensor Network (WSN) is collection of wireless sensors with limited memory, processing and energy supply. Based on application, sensors distribute in a wide geographically area in order to collect information and transmit the collected data packets toward a base station also called Sink. Due to the relatively high node density and source-to-sink communication pattern, congestion is a critical issue in WSN. Congestion not only causes packet loss, but also leads to excessive energy consumption as well as delay. To address this problem, in this paper we propose a new fuzzy logic based mechanism to detect and control congestion in each grid in WSN. In the proposed approach, sink select one node in each grid as Monitor Node. In addition, sink defines congestion candidate grids. Each Monitor Node in congestion candidate grids continually monitors the network and fetches the fuzzy controller inputs in order to determine level of congestion in each grid. Based on the congestion level, packets forward through the grid or relay nodes. Simulation results show that our approach has higher packet delivery ratio and lower packet loss than existing approaches.