Wireless Sensor Networks (WSNs) are characterized by the collaborative information transmission from multiple sensor nodes observing a physical phenomenon. Due to the limited capacity of shared wireless medium and memory restrictions of the sensor nodes, channel contention and network congestion can be experienced during the operation of the network. In fact, the level of local contention and the network congestion are closely coupled due to the multi-hop nature of sensor networks. Therefore, the unique characteristics of WSN call for a comprehensive analysis of the network congestion and contention under different network conditions. In this paper, we comprehensively investigate the interactions between contention resolution and congestion control mechanisms in WSN. An extensive set of simulations are performed in order to quantify the impacts of several network parameters on the overall network performance. The results of our analysis reveal that local interactions between sensor nodes directly affects the overall performance. The interdependency between network parameters call for adaptive cross-layer mechanisms for efficient data delivery in WSN.

Keywords

Wireless sensor networks, congestion detection and control, cross-layer design.