On The Linear Behaviour of the Throughput of IEEE 802.11 DCF in Non-Saturated Conditions

TL;DR

This paper introduces a linear model for the throughput of IEEE 802.11 DCF in non-saturated conditions, showing throughput depends linearly on packet arrival rate with a critical point for saturation.

Contribution

The paper presents a novel linear model for IEEE 802.11 DCF throughput in non-saturated traffic, extending previous models to include the effect of packet arrival rate and saturation threshold.

Findings

Throughput is linear in packet arrival rate below a critical threshold.

The model accurately predicts throughput behavior in non-saturated conditions.

Simulation results validate the theoretical model.

Abstract

We propose a linear model of the throughput of the IEEE 802.11 Distributed Coordination Function (DCF) protocol at the data link layer in non-saturated traffic conditions. We show that the throughput is a linear function of the packet arrival rate (PAR) $\lambda$ with a slope depending on both the number of contending stations and the average payload length. We also derive the interval of validity of the proposed model by showing the presence of a critical $\lambda$, above which the station begins operating in saturated traffic conditions. The analysis is based on the multi-dimensional Markovian state transition model proposed by Liaw \textit{et al.} with the aim of describing the behaviour of the MAC layer in unsaturated traffic conditions. Simulation results closely match the theoretical derivations, confirming the effectiveness of the proposed linear model.