Throughput Analysis and Rate Control for IEEE 802.11 Wireless LAN with Hidden Terminals

In this paper, we develop a Markov model to evaluate the performance of WLAN in the presence of hidden terminals. We focus on characterizing and studying the scenario of an access point with a population of clients partitioned into two mutually hidden groups, and derive a model to estimate the network throughput and the individual nodes' throughput. We propose a general methodology to solve the Markov chain by forming a nonlinear system of equations which describes the relationship between the conditional state transition probabilities, the transmission attempts probability and the steady state probability. Unlike alternative approaches, it is not necessary to invoke iterative methods to solve this system. We also demonstrate how our methodology and model can be used to estimate the optimal stable rate for each source in the WLAN as a means for rate control to achieve a given fairness principle between hidden groups of nodes and avoid starvation or congestion collapse for one group. Simulation results attest to the accuracy of our proposed model.