Cellular Mobile Telephone System Planning: Software Preparation and Testing

Index:

4029

Year:

2000

Thesis Title:

Cellular Mobile Telephone System Planning: Software Preparation and Testing

Student Name:

Salah Eldin Abdel Rahim Sorkatti

Supervisor:

Dr. Mohamed Ali Hmad Abas

Department:

Electrical

 

Abstract

 

The aim of this work is to design and implement a software program to be used in the planning stage of a cellular mobile telephone system.

The program was developed using the Visual Basic language. The program went through several planning steps to fulfill the mobile network planning task of locating cell sites to satisfy a given service area's RF signal strength (Coverage) as well as voice channel requirements (Capacity)

The planning process started with accepting the service area's geographical, morphostrucural and traffic parameters in the form of maps and data. After locating the cell sites, the process went through the median field strength prediction for each cell. Two path loss prediction models, Hata and Parson's, were adopted. Since the signal in the mobile environment is log-normally distributed around a median field A strength, a simulation for the log-normal probability distribution was made. This simulation was then used to calculate the coverage probability which represents a measure for the RF coverage.

The assignment probability, which is used as a mathematical model for cell shapes was then obtained. It was then used as a weighting factor to calculate the traffic load for each cell. A simulation for the Erlang_B formula was made to be used in the channel demand calculation for each cell.

A complete set of results was obtained. These results include two dimensional plots for the RF signal coverage and tables containing the design parameters like the cell location, height and power for each cell. The traffic load and number of channels were also obtained.

Although all the factors affecting the signal strength in the mobile environment were not taken into account, the results gave resonable indication about the RF signal strength coverage. More effort has to be exerted to include the interference calculation in order to come out with a good planning software that is able to go further in the frequency assignment problem and to give idea about the system performance.