Proportional fairness in wireless LANs and ad hoc networks

The paper considers scenarios in which fairness and efficiency are two conflicting objectives in wireless networks, and investigates the use of a proportional fairness objective to strike a balance between the two objectives. We explain the physical meaning of proportional fairness in a wireless network and give an analysis showing that proportional fairness is equivalent or close to max-min fairness in terms of air-time usage (as opposed to bandwidth usage). For infrastructure WLANs, two approaches to achieving proportional fairness are discussed. For ad hoc networks, achieving proportional fairness is more complex and requires global information on contention among different traffic flows. We propose and evaluate the use of a distributed max-min air-time allocation algorithm to approximate the proportional fairness objective.