Cognitive load-control for congested Wireless Sensor Network channels

Modern wireless sensors are capable of analyzing measured data and transmit at high rates if needed. They may individually or collectively select how much data shall be sent depending on predefined rules tied to properties of measured data. Sending rates thereby change triggered by events appearing in the sensor environment. With wireless technologies such as 802.15.4 (ZigBee) having limited capacity uncontrolled traffic can easily cause overload resulting in a decreased throughput. This paper presents a load control mechanism that uses multiple inputs, demand for transmission capacity and perceived quality at each sensor node, to properly configure sending rates of these nodes. The mechanism is based on Fuzzy Logic and quality assessed with utility functions for packet loss and throughput. NS-3 simulation results show clear improvements in overall throughput at high loads when the proposed mechanism is enabled.