Beyond the bits: cooperative packet recovery using physical layer information

ABSTRACT

Users increasingly depend on WLAN for business and entertainment. However, they occasionally experience dead spots and high loss rates. We show that these problems can be addressed by exposing information readily available at the physical layer. We make the physical layer convey its confidence that a particular bit is "0" or "1" to the higher layers. Access points that hear the same transmission communicate their confidence values over the wired Ethernet and combine their information to correct faulty bits in a corrupted packet. A single receiver may also combine the confidence estimates from multiple faulty retransmissions to obtain a correct packet. We implement our design and evaluate it using GNU software radios. The results show that our approach reduces loss rate by up to 10x in comparison with the current approach, and significantly outperforms prior packet combining proposals.

REFERENCES

• 1: 100 Gigabit Ethernet Transmission Sets New Record, 2006. http://arstechnica.com/news.ars/post/20061115-8231.html.
• 2: T. W. A. Avudainayagam, J. M. Shea and L. Xin. Reliability Exchange Schemes for Iterative Packet Combining in Distributed Arrays. In Proc. of the IEEE WCNC, volume 2, pages 832 -- 837, 2003.
• 3: Anthony J. Nicholson , Yatin Chawathe , Mike Y. Chen , Brian D. Noble , David Wetherall, Improved access point selection, Proceedings of the 4th international conference on Mobile systems, applications and services, June 19-22, 2006, Uppsala, Sweden [doi>10.1145/1134680.1134705]
• 4: Daniel Aguayo , John Bicket , Sanjit Biswas , Glenn Judd , Robert Morris, Link-level measurements from an 802.11b mesh network, ACM SIGCOMM Computer Communication Review, v.34 n.4, October 2004
• 5: P. Bahl, J. Padhye, L. Ravindranath, M. Singh, A. Wolman, and B. Zill. DAIR: A Framework for Managing Enterprise Wireless Networks Using Desktop Infrastructure. In Hotnets, 2005.
• 6: E. Blossom. GNU Software Defined Radio. http://www.gnu.org/software/gnuradio, 2006.
• 7: D. G. Brennan. On the Maximal Signal-to-Noise Ratio Realizable from Several Noisy Signals. Proc. IRE, 43:1530, October 1955.
• 8: S. S. Chakraborty, E. Yli-Juuti, and M. Liinaharja. An ARQ Scheme with Packet Combining. IEEE Communication Letters, 1998.
• 9: S. Cheng and M. C. Valenti. Macrodiversity packet combining for the ieee 802.11a uplink. In IEEE WCNC, 2005.
• 10: S. Diggavi, N. Al-Dhahir, A. Stamoulis, and A. Calederbank. Great Expectations: The Value of Spatial Diversity in Wireless Networks. Proceedings of the IEEE, 92(2):219--270, Feb. 2004.
• 11: R. Gallagher. Low-Density Parity-Check Codes. MIT Press, Cambridge, MA, 1963.
• 12: Andrea Goldsmith, Wireless Communications, Cambridge University Press, New York, NY, 2005
• 13: V. Guruswami and M. Sudan. Reflections on Improved Decoding of Reed-Solomon and Algebraic Geometric Codes. IEEE Information Theory Society Newsletter, 52(1):6--12, 2002.
• 14: J. Hagenauer and P. Hoecher. A Viterbi Algorithm with Soft-Decision Outputs and its Applications. In IEEE GLOBECOM, 1989.
• 15: p. a. IEEE 802.11 WG. Wireless lan medium access control (mac) and physical layer (phy) specifications, 1999. http://standards.ieee.org/getieee802/802.11.html.
• 16: E. Inc. Universal software radio peripheral. http://ettus.com.
• 17: Kyle Jamieson , Hari Balakrishnan, PPR: partial packet recovery for wireless networks, Proceedings of the 2007 conference on Applications, technologies, architectures, and protocols for computer communications, August 27-31, 2007, Kyoto, Japan
• 18: J. Laneman, D. Tse, and G. Wornell. Cooperative diversity in wireless networks: Efficient protocols and outage behavior. IEEE Transactions on Information Theory, 50(12), 2004.
• 19: Allen Miu , Hari Balakrishnan , Can Emre Koksal, Improving loss resilience with multi-radio diversity in wireless networks, Proceedings of the 11th annual international conference on Mobile computing and networking, August 28-September 02, 2005, Cologne, Germany [doi>10.1145/1080829.1080832]
• 20: Charles Reis , Ratul Mahajan , Maya Rodrig , David Wetherall , John Zahorjan, Measurement-based models of delivery and interference in static wireless networks, ACM SIGCOMM Computer Communication Review, v.36 n.4, October 2006
• 21: Maya Rodrig , Charles Reis , Ratul Mahajan , David Wetherall , John Zahorjan, Measurement-based characterization of 802.11 in a hotspot setting, Proceedings of the 2005 ACM SIGCOMM workshop on Experimental approaches to wireless network design and analysis, August 22-22, 2005, Philadelphia, Pennsylvania, USA [doi>10.1145/1080148.1080150]
• 22: A. Scaglione, D. Goeckel, and J. Laneman. Cooperative communications in mobile ad hoc networks. IEEE Signal Processing Magazine, 23(5):18--29, 2006.
• 23: David Tse , Pramod Viswanath, Fundamentals of wireless communication, Cambridge University Press, New York, NY, 2005
• 24: M. C. Valenti. Improving uplink performance by macrodiversity combining packets from adjacent access points. IEEE WCNC, pages 636--641, 2003.
• 25: M. Wang, X. Weimin, and T. Brown. Soft Decision Metric Generation for QAM with Channel Estimation Error. IEEE Transactions on Communications, 50(7):1058--1061, 2002.
• 26: Samuel C. Yang, CDMA RF System Engineering, Artech House, Inc., Norwood, MA, 1998

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:
Algorithms, Design, Performance

Keywords:
cooperative receptions, diversity combining, wireless networks