Abstract
Along with the success of IEEE 802.11-compliant WLANs, the distributed coordinated function (DCF) specified as the contention-based medium access mechanism in IEEE 802.11 has been widely used to support applications in new regimes. A thorough understanding of the characteristics of IEEE 802.11 DCF is therefore a research focus. DCF assumes the binary exponential backoff algorithm (BEBA) [D. Bertsekas, R. Gallager, Data Networks, Prentice Hall, 1992]. Several existing models that characterize BEBA as a p-persistent scheme have ignored several subtle protocol details. This has practically constrained the models from being applied in a broader range of configurations, e.g., small contention window, and from being further extended, e.g., 802.11e EDCA. In this paper, we develop an analytical model that captures the subtlety, and faithfully describes the channel activities as governed by DCF. Based on the devised model, we perform a rigorous analysis on the saturation throughput performance in a single-hop WLAN. We show that the stochastic property of the backoff time, r, may substantially impact the system performance. For example, setting the range of r to [1, CW] instead of [0, CW - 1], can degrade the system throughput considerably. We also identify, by clearly defining and thus being able to differentiate the two terms, attempt probability and transmission probability, an erroneous extension made to Bianchi's model [G. Bianchi, Performance analysis of the IEEE 802.11 distributed coordination function, IEEE JSAC, 18(3) (2000) 535-547]. All the findings are corroborated by ns-2 simulation.
| Original language | English |
|---|---|
| Pages (from-to) | 61-76 |
| Number of pages | 16 |
| Journal | Computer Networks |
| Volume | 52 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2008 Jan 18 |
Bibliographical note
Funding Information:Jennifer C. Hou received her Ph.D. degree in EECS in 1993 from The University of Michigan, Ann Arbor, MI. She was an assistant professor in Electrical and Computer Engineering at The University of Wisconsin, Madison, WI in 1993–1996, and an assistant/associate professor in Electrical Engineering at The Ohio State University in 1996–2001. Since August 2001, she has been with the Department of Computer Science at University of Illinois at Urbana Champaign, IL, where she is currently an associate professor. She was a recipient of the Lumley Research Award from Ohio State University in 2001, the NSF CAREER award from NSF in 1996–2000 and the Women in Science Initiative Award from The University of Wisconsin-Madison in 1993–1995. She has published over one hundred papers in archived journals and peer-reviewed conferences. She has been on the TPC of several major networking, real-time, and distributed systems conferences/symposiums, and was the Technical Program Chair of IEEE RTAS 2000 and IEEE IPSN 2004, a Program Vice Chair of IEEE ICDCS 2002, IEEE ICPADS 2004, IEEE RTSS 2004, and the General Co-Chair of IEEE RTAS 2001. She is on the editorial board of IEEE Transactions on Wireless Communications, IEEE Transactions on Parallel and Distributed Systems, ACM/Kluwer Wireless Networks, Kluwer Computer Networks, and ACM Transactions on Sensor Networks. Her most recent research focus is in the areas of network modeling and simulation, network measurement and diagnostics, and wireless sensor networks. She is a senior member of IEEE and a member of ACM.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
Keywords
- Backoff algorithm
- IEEE 802.11 MAC
- Model
- p-Persistent
ASJC Scopus subject areas
- Computer Networks and Communications