Impact of Contention Window Cheating on Single-Hop IEEE 802.11e MANETs

Abstract

Abstract-This paper presents a work in progress which deals with the important and unresolved problem of node misbehavior. A realistic approach is used to determine the impact of contention window manipulation on IEEE 802.11e ad-hoc networks. It is explained why such networks are more prone to misbehavior. Novel results pertaining to the 802.11e standard are presented. Simulation analysis is done for several scenarios with a distinction made for uplink and downlink traffic. It is shown that a misbehaving node can jeopardize network performance, therefore, countermeasures to this problem need to be developed.

Impact of Misbehaviour on QoS in Wireless Mesh Networks

“…Since there is no impact of (and therefore no gain from) misbehaviour in nonsaturated networks [11], we ensure that the simulated network is saturated. We evaluate the saturation throughput for the given topology in section 3.1.…”

Modeling a Traffic Remapping Attack Game in a Multi-Hop Ad Hoc Network

“…At the MAC layer most attacks have found the IEEE 802.11 distributed coordination function (DCF) [16] an easy target. It has been shown in numerous studies that performing a backoff attack, i.e., changing the transmission deferment parameters (such as idle carrier sensing or backoff times) yields the attacker a considerable increase in throughput and access delays at the cost of neutral nodes [17], [18]. This type of attack has been extensively studied, though mostly in a single-hop setting which is not surprising given the single-hop nature of the MAC layer.…”

On the Impact of Backoff Misbehaving Nodes in IEEE 802.11 Networks

“…Our backoff misbehavior model is a generalized form of widely-used models for backoff misbehavior in the literature. For example, γ = 2 means that the misbehaving node also adopts binary exponential backoff, which is the model used in [1], [4], and γ = 1 means that the misbehaving node always fixes its contention window, which is the model used in [2], [6].…”

“…Backoff misbehavior can lead to severe problems, such as unfairness [1] and even denial-of-service [2]. In the literature, there are mainly two lines of work to deal with backoff misbehavior: backoff misbehavior detection [3], [4] and backoff misbehavior resilient protocol design [5], [6].…”

“…We first define a backoff misbehavior model that is a generalized form of widelyused models in the literature [1], [2], [5], [6]. Then, we proposed two performance metrics, throughput gain ratio and throughput degradation ratio, to quantify the impact of a misbehaving node in an 802.11 network.…”