Divert: fine-grained path selection for wireless LANs

ABSTRACT

The performance of Wireless Local Area Networks (WLANs)often suffers from link-layer frame losses caused by noise, interference, multipath, attenuation, and user mobility. We observe that frame losses often occur in bursts and that three of the five main causes of frame losses -- multipath, attenuation, mobility--depends on the transmission path traversed between an access point (AP)and a client station.In a typical WLAN deployment, different transmission paths to a client exist in places where overlapping coverage is provided by a set of neighboring APs. Using experimental measurements and analysis on a 802.11b testbed, we show that fine-grained path selection among a set of neighboring APs can significantly reduce path-dependent losses in WLANs.We design and implement a WLAN distribution system called Divert, which supports fine-grained path selection for downlink communications, on an 802.11b testbed. Divert reduces frame losses without consuming any extra bandwidth in the wireless medium. Our experimental results show that Divert can reduce frame loss rates in realistic scenarios by as much as 26% compared to a fixed-path scheme that uses the best available transmitter.

REFERENCES

• 1: IEEE 802.11b/d3.0 Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification, Aug. 1999.
• 2: IEEE Standards for Local and Metropolitan Area Networks: Standard for Port Based Network Access Control, Oct. 2001.
• 3: Arranz, M. G., Aguero, R., Munoz, L., and Mahonen, P. Behavior of UDP-based applications over IEEE 802.11 wireless networks. In Proc. of IEEE PIMRC'01 (San Diego, CA, Sept. 2001).
• 4: Vaduvur Bharghavan , Alan Demers , Scott Shenker , Lixia Zhang, MACAW: a media access protocol for wireless LAN's, Proceedings of the conference on Communications architectures, protocols and applications, p.212-225, August 31-September 02, 1994, London, United Kingdom
• 5: Tracy Camp , John Lusth , Jeff Matocha, Reduced cell switching in a mobile computing environment, Proceedings of the 6th annual international conference on Mobile computing and networking, p.143-154, August 06-11, 2000, Boston, Massachusetts, United States [doi>10.1145/345910.345935]
• 6: Derryberry, R. T., S. Gray, D. M. I., Mandyam, G., and Raghothaman, B. Transmit diversity in 3G CDMA systems. IEEE Communication Magazine (2002), 68--74.
• 7: David Eckhardt , Peter Steenkiste, Measurement and analysis of the error characteristics of an in-building wireless network, Conference proceedings on Applications, technologies, architectures, and protocols for computer communications, p.243-254, August 28-30, 1996, Palo Alto, California, United States
• 8: Furukawa, H., Hamabe, K., and Ushirokawa, A. SSDT--site selection diversity transmission power control for cdma forward link. IEEE JSAC 18 (2000), 1546--1554.
• 9: Gross, J., and Willig, A. Measurements of a Wireless Link in different RF-isolated Environments. In Proc. of European Wireless 2002 (Florence, Italy, February 2002).
• 10: Gavin Holland , Nitin Vaidya , Paramvir Bahl, A rate-adaptive MAC protocol for multi-Hop wireless networks, Proceedings of the 7th annual international conference on Mobile computing and networking, p.236-251, July 2001, Rome, Italy [doi>10.1145/381677.381700]
• 11: Jean Tourrilhes. Fragment adaptive reduction : Coping with various interferers in radio unlicensed bands. In Proc. of IEEE ICC'01 (St.-Petersburg, Russia, June 2001).
• 12: Jouni Malinen. Host AP driver for Intersil Prism2/2.5/3. http://hostap.epitest.fi/, 2003. Version 0.0.1.
• 13: Victor C. M. Leung , Andrew W. Y. Au, A wireless local area network employing distributed radio bridges, Wireless Networks, v.2 n.2, p.97-107, June 1996 [doi>10.1007/BF01225633]
• 14: Marchent, B., and McTiffin, M. J. Handover and macro diversity for 3rd generation mobile systems within atm fixed networks. In Proc. of IEEE GLOBECOM'96 (London, UK, Nov. 1996), pp. 1151--1155.
• 15: Mishra, A., Shin, M., and Arbaugh, W. An empirical analysis of the IEEE 802.11 MAC layer handoff process. Tech. Rep. 75, University of Maryland, 2002.
• 16: Miu, A., Apostolopoulos, J., Tan, W. T., and Trott, M. Low-latency wireless video over 802.11 networks using path diversity. In Proc. of IEEE ICME'03 (Baltimore, MD, July 2003).
• 17: Eytan Modiano, An adaptive algorithm for optimizing the packet size used in wireless ARQ protocols, Wireless Networks, v.5 n.4, p.279-286, July 1999 [doi>10.1023/A:1019111430288]
• 18: Monteleoni, C., and Jaakkola, T. Online learning of non-stationary sequences. In Proc. of Advances in Neural Information Processing Systems (2003).
• 19: Phatak, D., and Goff, T. A novel mechanism for data streaming across mutiple ip lnks for improving throughput and reliability in mobile environments. In Proc. of IEEE INFOCOM'02 (New York, NY, June 2002).
• 20: Theodore S. Rappaport, Wireless Communications: Principles and Practice, IEEE Press, Piscataway, NJ, 1996
• 21: Pablo Rodriguez , Rajiv Chakravorty , Julian Chesterfield , Ian Pratt , Suman Banerjee, MAR: a commuter router infrastructure for the mobile internet, Proceedings of the 2nd international conference on Mobile systems, applications, and services, June 06-09, 2004, Boston, MA, USA [doi>10.1145/990064.990091]
• 22: B. Sadeghi , V. Kanodia , A. Sabharwal , E. Knightly, Opportunistic media sccess for multirate ad hoc networks, Proceedings of the 8th annual international conference on Mobile computing and networking, September 23-28, 2002, Atlanta, Georgia, USA [doi>10.1145/570645.570650]
• 23: Minho Shin , Arunesh Mishra , William A. Arbaugh, Improving the latency of 802.11 hand-offs using neighbor graphs, Proceedings of the 2nd international conference on Mobile systems, applications, and services, June 06-09, 2004, Boston, MA, USA [doi>10.1145/990064.990076]
• 24: Snoeren, A. Adaptive inverse multiplexing for wide-area wireless networks. In Proc. of IEEE GLOBECOM'99 (Dec. 1999), pp. 1665--1672.
• 25: Tan, G., and Guttag, J. Time-based fairness improves performance in multi-rate WLANs. In Proc. of USENIX'04 (Boston, MA, June 2004).
• 26: Tang, C., and McKinley, P. K. Modeling multicast packet losses in wireless LANs. Tech. rep., Computer Science and Engineering Department, Michigan State University, May 2003.
• 27: Willig, A., Kubisch, M., Hoene, C., and Wolisz, A. Measurements of a wireless link in an industrial environment using an IEEE 802.11-compliant physical layer. In IEEE Transactions on Industrial Electronics (2003).
• 28: Petros Zerfos , Gary Zhong , Jerry Cheng , Haiyun Luo , Songwu Lu , Jefferey Jia-Ru Li, DIRAC: a software-based wireless router system, Proceedings of the 9th annual international conference on Mobile computing and networking, September 14-19, 2003, San Diego, CA, USA [doi>10.1145/938985.939009]

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Wireless communication

General Terms:
Design, Experimentation, Measurement, Performance

Keywords:
802.11, mobile systems, path diversity, wireless LAN