A Unified Model for Performance Analysis of 802.11 in Heterogeneous Traffic and Saturation Condition

Bianchi´s 2-Dimesional Markov model has laid the foundation for analysis of 802.11 CSMA/CA mechanism. However, the assumption that every station is saturated significantly degrades the accuracy of it since it is quite possible that the network exists in heterogeneous saturation status where some types of traffics are extremely saturated while other types of traffics are far from saturation. Although there are several analytical models under non-saturated assumption by introducing a constant probability that the station has packets awaiting transmission, they share two common weaknesses: the possibility of multiple packets arriving and the constant probability that a station has packet to send. Thus we establish a 3-Dimensional Markov model that introduces an additional Dimensional, the queue length, to solve them. We validated our analytical results of performance metrics of 802.11 under homogeneous and heterogeneous traffics by extensive simulations.