Packet Delay Metrics for IEEE 802.11 Distributed Coordination Function

Abstract

In this paper, we introduce a comprehensive packet delay analysis for wireless networks based on IEEE 802.11 Distributed Coordination Function (DCF). We develop mathematical models that calculate a set of packet delay metrics, namely a) the average packet delay for successfully transmitted packets, b) the average packet delay of successfully transmitted packets experiencing a specific number of collisions, c) the average packet drop time, d) the delay jitter and e) the delay distribution by computing the probability of a packet to be successfully transmitted experiencing delay time lower than a given value. All the developed models are based on calculating station's delay time at the transmission slot(s) plus the average time that station defers at backoff slots before successful transmission. The mathematical models are simple, computationally fast and can be used to build admission control algorithms. Simulation results show that our proposed mathematical analysis is highly accurate.

Modeling Responsiveness of Decentralized Service Discovery in Wireless Mesh Networks

“…There are several approaches to model packet transmission delays at the 802.11 MAC level, e.g. [17,18], which will not be considered due to their complexity. Bianchi [2] developed a Markov model to compute the 802.11 Distributed Coordination Function (DCF) saturation throughput.…”

Calculating voice capacity in IEEE 802.11 WLANs under basic access data traffic

“…The mathematical model presented in this paper, is based on: a) Bianchi's [2] work for the performance of the IEEE 802.11 DCF, b) H. Wu's [3] work, which extends Bianchi's model to include packet dropping, c) P. Raptis [4] work for the computation of average packet delay, d) B. D. Amanatiadis [5] analytical model for voice capacity.…”

“…The model of [2] is extended in [3] to take into consideration packet dropping when the packet retransmission limit is reached, as specified in the IEEE 802.11 standard. Based on the analytical model of [2] and its extension of [3], an analytical model was developed by [4] for the calculation of average packet delay and jitter (standard deviation of the packet delay). In this work, considering works of [2], [3], and [4] This paper is organized as follows: Section II describes the DCF mechanism and the backoff procedure.…”

“…Based on the analytical model of [2] and its extension of [3], an analytical model was developed by [4] for the calculation of average packet delay and jitter (standard deviation of the packet delay). In this work, considering works of [2], [3], and [4] This paper is organized as follows: Section II describes the DCF mechanism and the backoff procedure. Section III subsection A describes the examined network scenario and subsection B presents the characteristics of some popular voice encoders.…”

A Method for Estimating Access Delay Distribution in IEEE 802.11 Networks

“…A large number of papers focus on the average and variance of packet delay [3], [4]; however, these moments are typically inadequate for delay sensitive applications where percentile delay distribution is needed. Existing approaches to estimating access delay in 802.11 networks make non-realistic assumptions such as network being under saturated traffic, no hidden node being present in the network, number of competing nodes being known, or no loss happening due to physical layer errors [5]- [9]. As mentioned earlier, inefficiencies of RTS/CTS signaling for mitigating hidden node problem preclude VCS as a feasible solution.…”