Modeling and Analysis of Bandwidth Competition in 802.11 Networks

• Main Authors: GU, Qijun, CHU, Chao-Hsien, LIU, Peng
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2007
• Subjects: Markov chain; bandwidth competition; IEEE 802.11; wireless LANs; congestion; wireless networks; local area networks; quality of service; QoS; Computer Sciences; Digital Communications and Networking
• Online Access: https://ink.library.smu.edu.sg/sis_research/1782; http://dx.doi.org/10.1504/IJMNDI.2007.017323
• Institution: Singapore Management University

In a wireless network, bandwidth is shared and nodes are in fact 'competing' with each other for resources. Therefore, the Quality of Service (QoS) an individual node can offer to applications is determined by how intense the competition is and how much bandwidth it can win in the competition. In this paper, we propose a Markov chain model to study the bandwidth competition in 802.11 networks. A set of heuristic formulas are derived to analyse and predict bandwidth competition. The formulas can be used to compute the exact quantity of bandwidth allocated to competing nodes, given their demands and their traffic parameters. It is illustrated that nodes that demand the same amount of bandwidth may receive very different allocations, and nodes that demand more bandwidth do not always obtain more bandwidth than other nodes. The findings in this study imply that (1) nodes can share the bandwidth precisely according to their demands with full cooperation, (2) or a node can guarantee its own bandwidth while suppressing others with a deliberate consideration in composing packets.