Competition, Cooperation, and Optimization in Multi-Hop CSMA Networks with Correlated Traffic

The purpose of this paper is to present a new method for the study of the competition and cooperation relationships among nodes in a network using a CSMA (Carrier Sense Multiple Access) protocol implemented with an exponential backoff process. Self-organized behavior is proposed. Standard topologies, such as tandem, traffic splitting and merging, are studied with variables: 1) backoff rate, 2) topology position, 3) traffic splitting. Several interesting phenomena are reported. We propose a "Channel Utilization Model" with a new derived variable "channel access rate" which can be used for all traffic loads. These models are applied with different optimization methods. Special strategies, for example "MAC Friendliness" [Shi et al. 2007], are also presented for serving special traffic like emergency traffic.