DOI QR코드

DOI QR Code

A Study on Time Synchronization Protocol to Cover Efficient Power Management in Ubiquitous Sensor Network

유비쿼터스 센서 네트워크를 위한 효율적인 시간 동기화 프로토콜 연구

  • Received : 2009.07.20
  • Accepted : 2010.03.18
  • Published : 2010.03.31

Abstract

The sensor networks can be used attractively for various application areas. Time synchronization is important for any Ubiquitous Sensor Networks (USN) systems. USN makes extensive use of synchronized time in many contexts for data fusion. However existing time synchronization protocols are available only for homogeneous sensor nodes of USN. It needs to be extended or redesigned in order to apply to the USN with heterogeneous sensor nodes. Because heterogeneous sensor nodes have different clock sources with the SinkNode of USN, it is impossible to be synchronized global time. In addition, energy efficiency is one of the most significant factors to influence the design of sensor networks, as sensor nodes are limited in power, computational capacity, and memory. In this paper, we propose specific time synchronization based on master-slave topology for the global time synchronization of USN with heterogeneous sensor nodes. The time synchronization master nodes are always able to be synchronized with the SinkNode. Then time synchronization master nodes enable time synchronization slave nodes to be synchronized sleep periods. The proposed master-slave time synchronization for heterogeneous sensor nodes of USN is also helpful for power saving by maintaining maximum sleep time.

유비쿼터스 센서 네트워크 환경은 다양한 이기종의 센서와 센서들 상호간의 통신을 통해 데이터를 수집하고 제공하여 물리공간의 지능화된 환경을 제공한다. 이러한 상태감지를 위한 센서노드들은 싱크노드와 센서노드로 구성되는데 이기종 센서 노드들간의 시간동기화를 고려하지 않고 전체 센서네트워크의 시간 동기화가 불가능 하게 된다는 문제점이 발생한다. 이러한 이기종 센서노드들간의 시간동기화 문제를 해결하기 위해서 본 논문에서는 싱크노드 아래의 센서노드들 중 싱크노드와 클럭소스가 같은 센서노드를 시간동기 마스터로 설정하고, 싱크노드와 다른 클럭소스를 가지는 센서노드를 마스터 아래에 속하는 시간동기 슬레이브로 설정하여 시간동기 마스터가 동작을 개시 할 때에만 시간동기 슬레이브 노드들이 동작하도록 하는 마스터 슬레이브 시간동기화 기법을 제안한다. 제안하는 마스터-슬레이브 토폴로지 기반 시간 동기화 기법은 센서의 설치가 용이하지 않은 USN환경에서 최대 슬립타임을 유지함으로써 센서의 전력소모를 최소화 할 수 있다.

Keywords

References

  1. G.Asada, M.Dong, T. Lin, F.Newberg, G.Pottie. W.Kaiser and H.O.Marcy, "Wireless integrated network sensors:low power systems on a chip," in Prc. Of the 24th European Solid-State Circuits Conference, The Haiue, Netherlands, Sept, 1998.
  2. M. Lemmon, J. Ganguly, and L. Xia, "Model-based clock synchronization in networks with drifting clocks", in Prc. Of the 2000 Pacific Rim International Symposium on Depenable Computing, Los Angeles, CA, Dec, 2002.
  3. R. Ostrovsky and B. Patt-Shamir, "Optimal and efficient clock synchronization under drifting clocks", in Prc. of the 18th ACM Symposium on Principles of Distributed Computing(PODC1999), 1999.
  4. http://www.zigbee.org/
  5. D. L. Milis, "Internet time synchronization: the network time protocol", IEEE Trans. Communications, vol. 39, no. 10, pp.1482-1493. Oct, 1991. https://doi.org/10.1109/26.103043
  6. J. Elson and D. Estrin, "Time synchronization for wireless sensor networks," in Proc. Of the 2001 International Parallel and Distributed Processing Symposium(IPDPS), Workshop on Parallel and Distributed Computing Issues in Wireless Networks and Mobile Computing, San Francisco, CA, Apr, 2001.
  7. K. Romer, "Time synchronization in ad hoc networks," in Proc. Of ACM Mobihoc, Long Beach, CA, 2001.
  8. I.F. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, "Wireless sensor networks: a survey", published by Elsevier Science, Dec, 2001.
  9. J. Heidemann, F. Silva, C. Intanagonwiwat, "Building efficient wireless sensor networks with low-level naming ," in Proc. Of the Operating Systems Principles, Banff, Canada, 2001.
  10. C. Intanagonwiwat, R. Govindan, D, Estrin, "Directed deffusion : a scalable and robust communication paradigm for sensor networks in Proc. of the ACM MobiCom'00, Boston, Ma, pp.55-67, 2000.
  11. C. Jaikaeo, C. Srisathapornphat, C. Shen, "Diagnosis of sensor networks", IEEE International conference on Communications ICC'01, Helsinki, Finland.,Jun, 2001.
  12. Yang.H and Sikdar. B "A Protocol for tracking mobile targets using sensor network," IEEE Workshop on Sensor Network Protocols and Applications, May 2003
  13. M.Sichitiu, C.Veerarittiphan, " Simple, Accurate Time Synchronization for Wireless Sensor Networks"
  14. J. Elson, L. Girod, and D. Estrin, "Fine-grained network time synchronization using reference broadcasts" in UCLA Technical Report 020008, Feb, 2002.
  15. Generiwal, S., Kumar, R. and Srivastada,M. 'Timing Sync Protocol for Sensor Networks", The first ACM conference
  16. M.Maroti, B. Kusy, G. Simon, and A. Ledeczi, "The Flooding Time Synchronization Protocol", In the proc. Of Sensys'04, Baltimore, Maryland, 2004.
  17. W. Ye, J. Heidemann and D. Estrin. "An energy efficient mac protocol for wireless sensor networks", In IEEE INFOCOM, 2002.