Interference Aware Routing and Load Balancing in Wireless Sensor and Actuator Networks

Abstract

In wireless sensor and actuator network (WSANs) there usually exists critical data, such as alarms and emergent event reports, that require short time delivery with high reliability but data volume is relatively small. At the same time, there exists larger volume of bulk sensor data which typically is delay tolerant and should be transmitted in the most energy efficient manner. On the 2.4 GHz ISM-band, the coexistence of the WSANs with WLANs imposes great challenge for designing reliable WSAN protocols. In this paper, we propose new sink initiated routing protocol that supports the two above mentioned traffic classes and is aware of the interference situation of the network. Critical data is transmitted using most interference resilient and reliable paths that minimize the expected transmission delay while the bulk data is transmitted in the most energy efficient manner by applying load balancing over several paths. The use of load balancing aims to even out the energy consumption of the intermediate nodes and thus maximize the operation time of the network. Our routing protocol estimates the link reliability based on the strength and activity of the interference as well as the path loss of the link and is able to adapt the routes based on changes in the propagation conditions and WLAN interference.