volume | PIER Journals

Abstract

The wireless communications in a tree canopy is essential for pre-harvesting control of fruit productions. To efficiently communicate between a sensor node and a sink node, channel characteristics in a tree canopy must be well-established. In this paper, propagation channel characteristics at the frequencies of 2.45 and 5.2 GHz have been estimated for designing a wireless communication system in a tree canopy. The proposed solution is based on measured path loss, time-varying signal strength and Angle of Arrival (AoA) for various paths in a tree canopy to estimate the channel. Since the waves reflect, refract, diffract and scatter from the foliage, it is complicated to find the true travelling path between a transmitter and a receiver at the nodes. The AoA estimator is used for physical interpretation of the channel. The experimental results demonstrate the channels in a tree canopy are mostly matched with the General Extreme Value model. The measured path gains illustrate that the appropriate antenna patterns must be selected to enhance the reliability of the system.

1. Akyildiz, F., W. Su, Y. Sankarasubramaniam, and E. Cayirci, "Wireless sensor network: Survey," Computer Network, Vol. 38, 393-422, 2002.
doi:10.1016/S1389-1286(01)00302-4

2. Ochiai, H., H. Ishizuka, Y. Kawakami, and H. Esaki, "A DTN-based sensor data gathering for agricultural applications," IEEE Sensor Journal, Vol. 11, No. 11, 2861-2868, Nov. 2011.
doi:10.1109/JSEN.2011.2170562

3. Alejos, A. V., M. G. Sánchez, I. Cuiñas, and J. C. G. Valladares, "Sensor area network for active RTLS in RFID tracking applications at 2.4 GHz ," Progress In Electromagnetics Research, Vol. 110, 43-58, 2010.
doi:10.2528/PIER10100204

4. Krairiksh, M., J. Varith, and A. Kanjanavapastit, "Wireless sensor network for monitoring maturity stage of fruit," Science Research/Wireless Sensor Network, Vol. 3, 318-321, 2011.
doi:10.4236/wsn.2011.39034

5. De Jong, Y. L. C. and M. H. A. Herben, "A tree-scattering model for improved propagation prediction in urban microcells," IEEE Trans. on Vehicular Technology, Vol. 53, No. 2, 503-513, Mar. 2004.
doi:10.1109/TVT.2004.823493

6. Chee, K. L., S. A. Torrico, and T. Kurner, "Foliage attenuation over mixed terrains in rural areas for broadband wireless access at 3.5 GHz," IEEE Trans. on Antennas and Propagation, Vol. 59, No. 7, 2698-2706, Jul. 2011.
doi:10.1109/TAP.2011.2152340

7. Au, W. C., L. Tsang, R. T. Shin, and J. A. Kong, "Collective scattering and absorption effects in microwave interaction with vegetation canopies," Progress In Electromagnetics Research, Vol. 14, 181-23, 1996.

8. De Matthaeis, P. and R. H. Lang, "Microwave scattering models for cylindrical vegetation components," Progress In Electromagnetics Research, Vol. 55, 307-333, 2005.
doi:10.2528/PIER05040602

9. Bultitude, R. J. C., "Measured characteristics of 800/900MHz fading radio channels with high angle propagation through moderately dense foliage," IEEE Journal on Selected Areas in Communications, Vol. 5, No. 2, 116-127, Feb. 1987.
doi:10.1109/JSAC.1987.1146517

10. Dalley, J. E. J., M. S. Smith, and D. N. Adams, "Propagation losses due to foliage at various frequencies," National Conference on Antennas and Propagation Publication, No. 461, 267-270, Mar.-Apr. 1999.

11. Lewenz, R., "Path loss variation due to vegetation movement," National Conference on Antennas and Propagation Publication, No. 461, 97-100, Mar.-Apr. 1999.

12. Perras, S. and L. Bouchard, "Fading characteristics of RF signals due to foliage in frequency bands from 2 to 60 GHz," Proc. 5th Int. Symp. Wireless Personal Multimedia Commun., 267-271.

13. Cuiñas, I., A. V. Alejos, M. G. Sánchez, P. Gómez, and R. F. S. Caldeirinha, "Wind effect on the scattering from vegetation at cellular phone frequencies," Proc. of International Geoscience and Remote Sensing Symposium, 369-372, 2007.

14. Pelet, E. R., J. E. Salt, and G. Wells, "Effect of wind on foliage obstructed line of-sight channel at 2.5 GHz," IEEE Trans. on Broadcasting, Vol. 50, No. 3, 224-232, Sep. 2004.
doi:10.1109/TBC.2004.834014

15. Hashim, M. H. and S. Starou, "Measurements and modeling of wind in°uence on radiowave propagation through vegetation," IEEE Trans. on Wireless Communications, Vol. 5, No. 5, 1055-1064, May 2006.
doi:10.1109/TWC.2006.1633358

16. Meng, Y. S., Y. H. Lee, and B. H. Ng, "Investigation of rainfall effect on forested radio wave propagation," IEEE Trans. on Antennas and Wireless Propagation Letters, Vol. 7, 159-162, 2008.
doi:10.1109/LAWP.2008.922052

17. Meng, Y. S., Y. H. Lee, and B. C. Ng, "The effects of tropical weather on radio-wave propagation over foliage channel," IEEE Trans. on Vehicular Technology, Vol. 58, No. 8, 4023-4030, Oct. 2009.
doi:10.1109/TVT.2009.2021480

18. Meng, Y. S. and Y. H. Lee, "Investigations of foliage effect on modern wireless communication systems: A review," Progress In Electromagnetics Research, Vol. 105, 313-332, 2010.
doi:10.2528/PIER10042605

19. Blaunstein, N., D. Censor, D. Katz, A. Freedman, and I. Matityahu, "Radio propagation in rural residential areas with vegetation ," Progress In Electromagnetics Research, Vol. 40, 131-153, 2003.
doi:10.2528/PIER02083003

20. Gay-Fernández, J. A., M. G. Sánchez, I. Cuiñas, A. V. Alejos, J. G. Sánchez, and J. L. Milanda-Sierra, "Propagation analysis and deployment of a wireless sensor network in a forest," Progress In Electromagnetics Research, Vol. 106, 121-145, 2010.
doi:10.2528/PIER10040806

21. Alejos, A. V., M. Dawood, and L. Medina, "Experimental dynamical evolution of the Brillouin precursor for broadband wireless communication through vegetation," Progress In Electromagnetics Research, Vol. 111, 291-309, 2011.
doi:10.2528/PIER10100706

22. Morgadinho, S., R. F. S. Caldeirinha, M. O. Al-Nuaimi, I. Cuiñas, M. C. Sancház, T. R. Fernandes, and J. Richter, "Time-variant radio channel characterization and modelling of vegetation media at millimeter-wave frequency," IEEE Trans. on Antennas and Propagation, Vol. 60, No. 3, 1557-1568, Mar. 2012.
doi:10.1109/TAP.2011.2180301

23. Sooksumrarn, P. and M. Krairiksh, "UHF wireless communication channel in a tree canopy," Proc. of International Symposium on Antennas and Propagation, 311-314, Oct.-Nov. 2012.

24. Kamarudin, M. R., Y. I. Nechayev, and P. S. Hall, "Onbody diversity and angle-of-arrival measurement using a pattern switching antenna," IEEE Trans. on Antennas and Propagation, Vol. 57, No. 4, 964-971, Apr. 2009.
doi:10.1109/TAP.2009.2014597

25. Sooksumrarn, P. and M. Krairiksh, "Dual-band mobile angle of arrival estimator," Proc. of Asia-Pacific Microwave Conference, 729-732, Dec. 2010.

26. Torrico, S. A. and R. H. Lang, "A simplified analytical model to predict the specific attenuation of a tree canopy," IEEE Trans. on Vehicular Technology, Vol. 56, No. 2, 696-703, Mar. 2007.
doi:10.1109/TVT.2007.891485

27. Saunders, S. R. and A. A. Zavala, Antennas and Propagation for Wireless Communication Systems, 2nd Ed., John Wiley, 2007.

28. Cuiñas, I., J. A. Gay-Fernández, P. Gómez, A. V. Alejos, and M. G. Sánchez, "Radioelectric propagation in mature wet forests at 5.8 GHz," Proc. of IEEE International Symposium on Antennas and Propagation Society, 2009.

Dr. Pobsook Sooksumrarn

Dr. Chainarong Kittiyanpunya

Dr. Paiboon Yoiyod

Prof. Monai Krairiksh