Performance analysis of the IEEE 802.11 distributed coordination function

TLDR

The IEEE 802.11 standard defines wireless LANs, with its primary MAC technique, the distributed coordination function (DCF), being a CSMA/CA scheme that uses binary slotted exponential backoff. This paper develops a highly accurate analytical model for computing 802.11 DCF throughput under finite terminal counts and ideal channel conditions. The model applies to both basic access and RTS/CTS schemes, and to a hybrid where packets above a threshold use RTS/CTS. Using the model, we evaluate throughput performance extensively for both access mechanisms of 802.11.

Abstract

The IEEE has standardized the 802.11 protocol for wireless local area networks. The primary medium access control (MAC) technique of 802.11 is called the distributed coordination function (DCF). The DCF is a carrier sense multiple access with collision avoidance (CSMA/CA) scheme with binary slotted exponential backoff. This paper provides a simple, but nevertheless extremely accurate, analytical model to compute the 802.11 DCF throughput, in the assumption of finite number of terminals and ideal channel conditions. The proposed analysis applies to both the packet transmission schemes employed by DCF, namely, the basic access and the RTS/CTS access mechanisms. In addition, it also applies to a combination of the two schemes, in which packets longer than a given threshold are transmitted according to the RTS/CTS mechanism. By means of the proposed model, we provide an extensive throughput performance evaluation of both access mechanisms of the 802.11 protocol.