부산대학교 도서관

Even if the traffic pattern is known and the network topology is simple, a strong congestion can take place in wireless sensor networks (WSNs) due to the data gathering effect and the duty-cycle operation. In this paper, we propose a novel medium access control (MAC) protocol to alleviate the congestion, which is referred to as the congestion alleviation-MAC (CA-MAC). It adopts an adaptive contention window (ACW), which allows the nodes with more buffered packets to transmit with a higher probability, as well as an intelligent burst packet transmission when the congested nodes seize the channel. Simulations are performed in NS-2, and results show that the proposed CA-MAC protocol achieves a good performance in terms of the packet delivery ratio (PDR), power consumption, throughput, and average latency.