On Enhancing Event-to-Sink Data Delivery Throughput in Sensor Networks

The many-to-one multihop traffic pattern of Wireless Sensor Networks (WSNs) puts a great challenge on enhancing the event-to-sink data delivery throughput. Because, in CSMA/CA driven medium access control protocols, contention of the shared medium raises both at the event detection area and near the sink, which in turn increases the packet collisions greatly. In this paper, we exploit the amount of traffic load a node carries to control its medium access frequency by assigning the minimum contention window (CW_min) value in a differentiated way. The proposed scheme is fully distributed. The performance of the proposed scheme is evaluated by ns-2 simulations and the results show that it can significantly decrease the packet losses due to collisions and buffer drops, which in turn helps to enhance event-to-sink throughput. It also outperforms the existing approaches.