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Validation of an Improved Location-Based Handover Algorithm Using GSM Measurement Data
September/October 2005 (vol. 4 no. 5)
pp. 530-536
When a mobile station moves, the path loss and shadow fading contribute to the large-scale variation in the received signal strength. The variation of signal strength caused by shadow fadings is a random process, and handover decision mechanisms based on measurements of signal strength induce the "ping-pong effect.” This paper proposes an improved handover algorithm, based on the estimates of location and velocity of the mobile station, to suppress the ping-pong effect in cellular systems. A practical approach based on GSM measurement data is used to estimate the location and velocity of mobile station to identify the correlation among shadowing components. The impact of location errors on handover performance was examined, and the proposed handover algorithm was applied to a real GSM system in urban Taipei city. The results indicate that the number of unnecessary handover can be reduced 18-26 percent by the proposed approach, compared to the conventional method, while the signal outage probability remains similar. Besides, the computational complexity of the proposed algorithm is low, and the algorithm does not use a database or lookup table.

[1] E. Leu and B.L. Mark, “Modeling and Analysis of Fast Handoff Algorithms for Microcellular Networks,” Proc. 10th IEEE Symp. Modeling, Analysis and Simulation of Computer and Telecomm. Systems, pp. 321-328, Oct. 2002.
[2] A.E. Leu and B.L. Mark, “An Efficient Timer-Based Hard Handoff Algorithm for Cellular Networks,” Proc. IEEE Wireless Comm. and Networking Conf., vol. 2, pp. 1207-1212, Mar. 2003.
[3] M. Toril, S. Pedraza, R. Ferrer, and V. Wille, “Optimization of Handover Margins in GSM/GPRS Networks,” Proc. IEEE Vehicular Technology Conf., vol. 1, pp. 150-154, Apr. 2003.
[4] D.H. Kim, W. Noh, and S. An, “Speed-Sensitive Handoff under Dynamic Hierarchical Cellular Systems,” Proc. Ninth Int'l Conf. Computing, Comm. and Control Technology (CCCT '03), July 2003.
[5] B. Honman and W. Benjapolakul, “A Handover Decision Procedure for Mobile Telephone Systems Using Fuzzy Logic,” Proc. IEEE Asia-Pacific Conf. Circuits Systems, pp. 503-506, Nov. 1998.
[6] A. Majlesi and B.H. Khalaj, “An Adaptive Fuzzy Logic Based Handoff Algorithm for Hybrid Networks,” Proc. IEEE Conf. Signal Processing, vol. 2, pp. 1223-1228, Aug. 2002.
[7] S.S. Wang, M. Green, and M. Malkawi, “Adaptive Handoff Method Using Mobile Location Information,” Proc. IEEE Emerging Technology Symp. Broadband Comm. for the Internet Era Symp., pp. 97-101, Sept. 2001.
[8] W. Teerapabkajorndet and P. Krishnamurthy, “Comparison of Performance of Location-Aware and Traditional Handoff-Decision Algorithms in CDPD Networks,” Proc. IEEE Conf. Vehicular Technology, vol. 1, pp. 212-216, 2001.
[9] A. Markopoulos, P. Pissaris, S. Kyriazakos, C. Dimitriadis, G. Karetsos, and E.D. Sykas, “Increased Handover Performance in 2G and 3G Wireless Systems Based on Combined Mobile-Location and Area,” Proc. IEEE Int'l Symp. Wireless Personal Multimedia Comm., vol. 1, pp. 47-51, Oct. 2002.
[10] J. Eberspacher and H.-J. Vogel, GSM-Switching, Services and Protocols. John Wiley and Sons, 1998.
[11] M. Gudmundson, “Correlation Model for Shadow Fading in Mobile Radio Systems,” Electronics Letters, vol. 27, no. 23, pp. 2145-2146, Nov. 1991.
[12] D. Giancristofaro, “Correlation Model for Shadow Fading in Mobile Radio Channels,” Electronics Letters, vol. 32, pp. 958-959, May. 1996.
[13] J. Weitzen and T.J. Lowe, “Measurement of Angular and Distance Correlation Properties of Long-Normal Shadowing at 1900 MHz and Its Application to Design of PCS Systems,” IEEE Trans. Vehicular Technology, vol. 51, no. 2, Mar. 2002.
[14] S.R. Saunders, Antennas and Propagation for Wireless Communicaion Systems. John Wiley and Sons, 1999.
[15] D.B. Lin, R.T. Juang, H.P. Lin, and C.Y. Ke, “Mobile Location Estimation Based on Differences of Signal Attenuations for GSM Systems,” Proc. IEEE Soc. Int'l Conf. Antennas and Propagation, vol. 1, pp. 77-80, June 2003.
[16] H.P. Lin, D.B. Lin, and R.T. Juang, “Performance Enhancement for Microcell Planning Using Simple Genetic Algorithm,” Proc. IEEE Int'l Conf. Antennas and Propagation, vol. 4, pp. 664-667, June 2002.
[17] F. Graziosi, M. Pratesi, M. Ruggieri, and F. Santucci, “A Multicell Model of Handover Initiation in Mobile Cellular Networks,” IEEE Trans. Vehicular Technology, vol. 48, no. 3, May. 1999.
[18] G. Azemi, B. Senabji, and B. Boashash, “A Novel Estimator for the Velocity of a Mobile Station in a Micro-Cellular System,” Proc. Int'l Symp. Circuits and Systems, vol. 2, pp. 212-215, May 2003.
[19] K.I. Itoh, S. Watanabe, J.S. Shih, and T. Sato, “Performance of Handoff Algorithm Based on Distance and RSSI Measurements,” IEEE Trans. Vehicular Technology, vol. 51, no. 6, Nov. 2002.
[20] S.O. Rice, “Statistical Properties of a Sine Wave plus Random Noise,” Bell Systems Technical J., vol. 27 pp 109-157, Jan. 1948.

Index Terms:
Index Terms- Handover, mobile location, mobile velocity estimation, shadow fading.
Hsin-Piao Lin, Rong-Terng Juang, Ding-Bing Lin, "Validation of an Improved Location-Based Handover Algorithm Using GSM Measurement Data," IEEE Transactions on Mobile Computing, vol. 4, no. 5, pp. 530-536, Sept.-Oct. 2005, doi:10.1109/TMC.2005.73
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