한국통신학회논문지 (The Journal of Korean Institute of Communications and Information Sciences)

  • 제34권8A호
  • /
  • Pages.600-609
  • /
  • 2009
  • /
  • 1226-4717(pISSN)
  • /
  • 2287-3880(eISSN)
한국통신학회 (The Korean Institute of Commucations and Information Sciences)
권호 표지

실시간 무선 센서 네트워크에서 전송 지연 감소를 위한 MAC 개선 방안

Improvement of MAC Protocol to Reduce the Delay Latency in Real-Time Wireless Sensor Networks

  • 장호 (영남대학교 컴퓨터공학과) ;
  • 정원석 ((주)이노지오 연구개발팀) ;
  • 이기동 (영남대학교 컴퓨터공학과)
  • 발행 : 2009.08.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

기존의 IEEE 802.11 DCF(Distributed Coordination Function)와 같은 전통적인 CSMA(carrier sense multiple access) 프로토콜은 네트워크 규모가 커짐에 따라서 성능의 급격한 감쇠와 전송 지연 증가를 초래한다. 이러한 문제를 효과적으로 해결하기 위하여 본 논문에서는 무선 센서 네트워크에 적합한 MAC(medium access control) 프로토콜을 제안한다. 기존의 DCF 프로토콜은 데이터 전송을 위한 슬롯(slot)을 선택할 때 패킷 충돌로 인한 재전송이 반복될 때 마다 크기가 커지는 경쟁 윈도우(contention window) 내에서 일반 확률 분포(uniform probability distribution)를 이용한 랜덤(random) 선택 기법을 사용하지만 제안한 프로토콜에서는 전송 지연을 최대한 감소시키기 위하여 경쟁 윈도우의 크기를 고정시키고, 전송 슬롯을 보다 효율적으로 선택하도록 비 균등(non-uniform)확률 분포를 사용하여 전송 슬롯을 랜덤하게 선정한다. 시뮬레이션을 통하여 제안한 프로토콜이 802.11 MAC 표준에 비하여 전송 지연이 감소함을 보여 전송 지연에 민감한 실시간 무선 센서 네트워크의 최적 지연 한계점(best latency bound)을 충족시키는 프로토콜임을 입증한다.

The traditional carrier sense multiple access (CSMA) protocol like IEEE 802.11 Distributed Coordination Function (DCF) does not handle the constraints adequately, leading to degraded delay latency and throughput as the network scales are enlarged. We present more efficient method of a medium access for real-time wireless sensor networks. Proposed MAC protocol is like the randomized CSMA protocol, but unlike previous legacy protocols, it does not use a time-varying contention window from which a node randomly picks a transmission slot. To reduce the latency for the delivery of event reports, we carefully decide to select a fixed-size contention window with non-uniform probability distribution of transmitting in each slot. We show that the proposed method can offer up to severaansimes latency reduction compared to legacy of IEEE 802.11 as the size of the sensor network scales up to 256 nodes using widely using network simulation package,caS-2. We finally show that proposed MAC scheme comes close to meet bounds on the best latency being achieved by a decentralized CSMA-based MAC protocol for real-time wireless sensor networks which is sensitive to delay latency.

키워드

참고문헌

  1. Z. Cai, M. Lu, X. Wang, 'Randomized Broadcast Channel Access Algorithms for Ad Hoc Networks,' In Proceedings of the IEEE International Conference on Parallel Processing, pp.151-158, 2002
  2. I. F. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, 'A Survey on Sensor Networks,' IEEE Communications Magazine, vol.40, no.8, pp.102-116, Aug. 2002 https://doi.org/10.1109/MCOM.2002.1024422
  3. I. Demirkol, C. Ersoy, and F. Alagoz, 'MAC Protocols for Wireless Sensor Networks: a Survey,' IEEE Communications Magazine, 2005 https://doi.org/10.1109/MCOM.2006.1632658
  4. V. Rajaravivarma, Y. Yi, and Y. Teng, 'An overview of wireless sensor network and applications,' In Proceedings of the 35th Southeastern Symposium on System Theory, pp.432-436, Morgantown, WVa, USA, Mar. 2003
  5. A. Abu-El Humos, 'Low Latency and Energy Efficient MAC Protocols for Wireless Sensor Networks,' Ph.D. Dissertation, Florida Atlantic University, Boca Raton, Florida, Aug. 2005
  6. M. Gast, 802.11 Wireless Networks: The Definitive Guide, 2nd ED., O'Reilly, Apr. 2005
  7. IEEE Std. 802.11-1999, Part 11, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, Reference number ISO/IEC 8802-11:1999(E), IEEE Std. 802.11, 1999 edition, 1999
  8. J. Polastre, J. Hill, and D. Culler, 'Versatile Low Power Media Access for Wireless Sensor Networks,' In Proceedings of the Second ACM Conference on Embedded Networked Sensor Systems(SenSys), Baltimore, MD, pp.95-107, Nov. 2004 https://doi.org/10.1145/1031495.1031508
  9. W. Ye, J. Heidemann, and D. Estrin, 'An Energy Efficient MAC protocol for Wireless Sensor Networks,' In Proceedings of IEEE INFOCOM 2002, Vol.21, No.1, pp.1567-1576, 2002 https://doi.org/10.1109/INFCOM.2002.1019408
  10. V. Bharghavan et al., 'MACAW: A Media Access Protocol for Wireless LANs,' In Proceedings of ACM SIGCOMM '94, Vol.24, No.4, pp.212-225, 1994 https://doi.org/10.1145/190314.190334
  11. USC ISI, ns-2 Notes and Documentation, 2007
  12. A. Woo, and D. Culler, 'A Transmission Control Scheme for Media Access in Sensor Networks,' In Proceedings of ACM MobiCom '01, Rome, Italy, pp.221-235, Jul. 2001 https://doi.org/10.1145/381677.381699
  13. N. Vaidya, A. Dugar, S. Gupta, and P. Bahl, 'Distributed Fair Scheduling in a Wireless LAN,' IEEE Transactions on Mobile Computing, Vol.4, No.6, pp.616-629, Nov/Dec. 2005 https://doi.org/10.1109/TMC.2005.87
  14. Z. Fang, B. Bensaou, and Y. Wang, 'Performance evaluation of a fair backoff algorithm for IEEE 802.11 DFWMAC,' MOBIHOC'02, ACM, 2002 https://doi.org/10.1145/513800.513807
  15. G. Bianchi, 'Performance Analysis of the IEEE 802.11 Distributed Coordination Function,' IEEE Journal on Selected Areas in Communication, Vol.18, No.3, pp.535-547, Mar. 2000 https://doi.org/10.1109/49.840210