Variations of GSM Path Loss Exponent with Propagation Distance at L-Band Frequencies in Different Microcellular Environment of Southwestern Nigeria

Abstract:

Propagation path loss exponent is an important component of system design, and knowing the values helps to avoid surprises when the actual service begins. The path loss exponent is known to be critical in establishing the coverage of any new cellular network. To estimate the path loss exponent of any environment requires raising new data sets, which can be accomplished by conducting experiments. With this objective, the present study reports the L-band signal RSS level measurements of 6 GSM base stations in the urban, suburban and rural environments of Ondo and Ekiti States in the Southwestern region of Nigeria. Using Sony Ericson TEMS phone monitoring device connected to a laptop equipped with TEMS software and base station cell reference and a GPS device, RSS measurements were performed in each sector of the base station up to 1200 meters employing single sector verification method. The values of path loss exponent were computed from the deduced values of path loss at 50 m intervals up to distances of 1200 meters. Close to the base station, the following exponent values were observed, between 2.0 to 3.8 in urban environment, 2.0 to 2.8 in suburban environment while for rural environment, 1.5 to 2.6 were observed. After the breakpoint distance higher path loss exponent values of up to 6 was recorded in urban environment, exponent value of up to 4.3 was observed in suburban environment and up to 3.5 exponent value in rural environment. It was also observed that the rural environment presented the longest breakpoint distance of 500 m. The high path-loss exponents observed especially in the urban environment could cause GSM operators to rethink the margins they have provided. This study is useful for the design of upcoming network systems in these regions and in similar regions.