An entropy based approach to evaluate the weighted fairness of shared medium access with/without multipacket reception

In this paper, we propose a new approach to evaluate the fairness of bandwidth allocation to distributed nodes in a local area network. When the source traffic pattern is fixed, the proposed approach is a mapping from the set of all medium access control (MAC) protocols to the interval [0,1] in the real line such that a larger value corresponds to a MAC protocol that allocates bandwidth more fairly. The approach is applicable for a wide range of medium access control schemes including those in which the packet lengths are not identical and/or multipacket reception (MPR) capability is available. To verify the correctness of the proposed approach, we use it to evaluate the fairness levels of an IEEE 802.11 wireless LAN composed of homogeneous or heterogeneous nodes. Our simulations indicate that for the IEEE 802.11 protocol, the short-term fairness level is low while the long-term fairness level is high. The entropy-based approach leads to a conclusion that is consistent to the previous finding in the literature.