Investigation Of Factors Affecting Cellcular Networks Coverage

Abstract

The performance of cellular networks is determined by the network  capacity and the coverage.  The cellular system coverage planning decide the service quality provided by the network operator in a given area. The good coverage means less calls drop, less outage probability, and accurate mobile position estimation.

In cellular networks, most of the mobile station will be close to their serving base stations, resulting in acceptable coverage. As the shadowing has a decisive effect on the cell acceptable coverage, the cell radius may be less than the value estimated using the path loss alone. Therefore, it is more appropriate to design the system in terms of the cell-edge coverage probability and location  variability effect.

In this paper, a reliable cell coverage model that consider the mobile station position is derived in shadowing environments. The model accuracy and cell coverage probability expressions were verified and  simulated with the modified two-ray path loss propagation model. The modified model is used to evaluate and plot the cell converge fraction against many controlling factors such as shadowing, antennas height, location  variability, and receiver sensitivity. 

The results show that the location variability is increased as the carrier frequency increased. Rural environments introduce more location variability than urban environments. It was also found that higher base station antenna can result in better cell coverage percentage and less shadowing effect. For the 3G cellular system designed so that 90% of locations at the cell edge have a reliable coverage, the path loss due to shadowing is equal to 6.9 dB in urban areas, and 8.12 dB in suburban environment.