Mobile WiMAX Coverage Evaluation for Rural Areas of India Gopal Chandra Manna, Bhavana Jharia Inspection Circle, BSNL, Jabalpur, M.P.India Dept, of Electronics and Communication Engg., Government Engineering College, Jabalpur, M.P. India gcmanna@yahoo.com, bhavanajharia@yahoo.co.in Abstract - Measurement of propagation parameters are essential for coverage and quality prediction. Commercially available planning tools are not customised for local geographical conditions, thus leading to inadequate service and unnecessary expenditure. Mobile WiMAX is under rapid installation throughout the globe. Present study made at rural areas of Rajasthan establishes lower path loss than the coverage prediction models recommended by WiMAX forum. Keywords: WiMAX, IEEE 802.16 , path loss exponent, Rayleigh fading, RSSI, CINR I. INTRODUCTION Mobile services for voice have been implemented in urban areas in redundant and many parts of the rural areas are still not covered. The economics of extending mobile services in a cost effective manner is a challenge to the network designers. Measurement of propagation parameters are essential for coverage and quality prediction. Cell edge probability and area coverage probability are calculated based on parameters like initial path loss, path loss exponent and Rayleigh fading factor . Jakes graph is usually deployed for prediction of cell radius. Now, Commercially available planning tools are deployed for estimation of coverage which includes clutter diagram and a suitable prediction model. Base transceiver station locations are plotted on the predicted coverage map plot. The studies were carried out at dense city like Kolkata and medium to small towns like Raipur, Jabalpur, Katni, Jagdalpur etc of India during 2006 to 2009[1].Measurements on GSM carried out revealed that Okumura-Hata model customised for typical geographical conditions matches receive signal level to a reasonable extent as per prediction only beyond half of Fresnel Zone distance and signal quality is adequate.Receive signal quality is very poor in near region of base station together with much higher signal strength than calculated free space signal strength leading to un-predictable communication. For CDMA ,the signal strength variation with distance is observed regular throughout;signal quality is nearly flat upto two times the Fresnel Zone distance after which signal quality drops sharply which makes communication to fail Observation similar to CDMA is found in case of WCDMA also but the range is numerically less than CDMA due deployment of higher frequency band of operation in WCDMA. Evolution of data service through voice channels has limitations in deployment of time-slots in GSM and code- channels in CDMA . Extension of mobile data services to rural areas needs thorough planning with greater importance to extend larger coverage than capacity and with compromising throughput. A study was conducted in 2007 to estimate the coverage of WiMAX based on IEEE 802.16 D at Kalyani, a suburban area of Kolkata City. Measurements were taken for rooftop antennas on line of sight (LoS) condition upto 4 km and backhaul throughput capacity of 2 mbps due to practical limitations. The throughput was observed full and signal quality was found adequate. For on road measurements involving both LOS and Non-LoS condition, the communication was found limited to 2 Km zone only[2]. Present study on WiMAX based on IEEE 802.16 E recommendation was conducted at two rural locations of Rajasthan during the months of November 2009 to February 2010 when cold wave flows and temperature reaches near freezing point of water. Morning time is full of fog, however, sky was almost clear during the period when observations were taken. The area covers light green vegetation with low height hills scattered here and there, otherwise mostly plain. The study measured all the three components for effective service and leads to estimate values of various communication parameters essential for estimation of coverage. As the two base stations used were far off and no other WiMAX system was in use , no cell concept was used neither the handover issue was taken into consideration. Section II discusses various propagation models based on which WiMAX coverage is predicted and a statistical approach for gross estimation of pathloss exponent and fading component. The various studies already conducted on several mobile communication technologies and results obtained has been stated in Section III. Base station setup, Subscriber Station location arrangements and methodology of data collection has been elaborated in section IV. Processing of data and results obtained has been given in section V followed by discussions and conclusion has been drawn in section VI. II. PROPAGATION MODELS Okumura Hata model is widely used for voice coverage in below 1500 MHz range and the same has been deployed with modification for prediction of WiMAX coverage ISBN 978-89-5519-154-7 942 Feb. 13~16, 2011 ICACT2011