Hierarchical modeling of IEEE 802.11 multi-hop wireless networks

Abstract

IEEE 802.11 is implemented in many wireless networks, including multi-hop networks where communications between nodes are conveyed along a chain. We present a modeling framework to evaluate the performance of flows conveyed through such a chain. Our framework is based on a hierarchical modeling composed of two levels. The lower level is dedicated to the modeling of each node, while the upper level matches the actual topology of the chain. Our approach can handle different topologies, takes into account Bit Error Rate and can be applied to multi-hop flows with rates ranging from light to heavy workloads. We assess the ability of our model to evaluate loss rate, throughput, and end-to-end delay experienced by flows on a simple scenario, where the number of nodes is limited to three. Numerical results show that our model accurately approximates the performance of flows with a relative error typically less than 10%.

Modeling of IEEE 802.11 multi-hop wireless chains with hidden nodes

“…Here, we extend markedly our proposed framework by introducing one important missing feature in the previous analysis, i.e., the hidden node problem which takes place in larger chains. Unlike our previous study of [1] in which virtually no frames collisions can occur, larger chains are prone to frequent frames collisions. In this paper, we present a practical means to handle these collisions within our modeling framework.…”

“…In [1] we introduce the first parts of a general framework for performance evaluation of a multi-hop wireless chain. The analysis was restricted to a simple scenario with only three nodes.…”

“…Following the framework developed in [1], our model is composed of two levels: a global queueing network model, and several local Markov chain models. Since only three nodes are effectively transmitting frames (node 4 only returns acknowledgments), the global queueing model associated with the chain is composed of three queues with fi- Figure 2.…”

“…We refer to these networks as chains. There is only a handful of works specifically devoted to the analytical performance evaluation of such chains based on IEEE 802.11 [2,4,1]. Besides, it seems that none of them handles at the same time realistic assumptions regarding the behavior of the MAC protocol, the inter-dependencies in the distribution of the workload among the nodes (some nodes may be in saturation while others may be in starvation) and the hidden node problem, which are fundamental properties of a wireless chain with several nodes.…”

“…In a previous paper [1], we analyzed the behavior of the simplest chain which has only one relay node. Though a necessary milestone, its limited size allowed us to overlook the well-known but complex issue of hidden node problem.…”