A Fair CSMA/CA Scheme: A Distance-Based Approach

With the rapid developments in communication technologies and the increase in the implementation of WSNs, sensor networks with better QoS have started to be developed. Furthermore, there was a need to develop more efficient medium access protocols to increase number of served users in dense deployments. In this paper, a novel CSMA/CA model, which prioritizes sensor nodes depending on their distance to the access point (AP), is proposed to provide a fairer communication to users positioned away from the AP. Therefore, the number of nodes receiving QoS above a certain throughput can be increased. The results show that the total throughput of the system increases when two priority levels are assigned to nodes. In addition to a 21 % improvement in the number of nodes transmitting above a certain speed, it has been shown that a fairer service can be provided by increasing the ratio of the data rate with low priority nodes over high priority nodes which is about 30% to 55%.