Seasonal Variations in GSM Path Loss at L-Band Frequency in Different Microcellular Environments of Southwestern Nigeria

Abstract

Quality of service is one of the major factors demanded by customers in
any communication network services. It is therefore essential to put into
consideration seasonal propagation parameters before designing and
establishing any wireless network systems in order to meet demands of
customers. In this research, investigation of RF channel behaviour based
on extensive measurements of signal strength and other propagation
parameters up to 1200 meters from the base stations adopting single sector
verification technique in wet and dry seasons are presented. The
measurements were carried out at 900 MHz and 1800 MHz bands in urban,
suburban and rural environments of Ondo and Ekiti States of Southwestern
Nigeria using Sony Ericson TEMS phones and global positioning system
connected to a laptop equipped with TEMS software and cell references of
the base stations in the studied areas. The measured data were analysed
and propagation parameters deduced. A log-normal shadowing path loss
model was formulated using the deduced propagation parameters. The
results obtained showed that GSM signals suffer more losses during the
wet season due to increased foliage and ground conductivity. Path loss
difference between wet and dry seasons was estimated using the developed
log-normal shadowing model to be around 0 to 2.4 dB, 0 to 5.5 dB and 0
to 7.0 dB for urban, suburban and rural environments respectively. These
estimated losses, though not significant in urban environment, were quite
significant in the suburban and rural environments. This study has
provided valuable data of additional losses GSM signals are likely to suffer
during the wet season for more proper planning and precise design of
coverage link of GSM channels to ensure all year round quality of service.