Measurement and Performance Analysis of Signal-to-interference Ratio in Wireless Networks

To evaluate the reliability and quality of signal of UMTS radio access technology of three cellular networks (MTN, 9mobile and Airtel network) over two cities in Nigeria, an intensive drive test measurement was conducted, taking into consideration, signal-to-interference ratio (Ec/Io) as the key performance indicator under study. A total of 10958, 11075 and 11109 Ec/Io measurements were obtained for MTN, 9mobile and Airtel network. These measured data were subjected to statistical analysis in the form of bar charts, quality plots and calculations of measures of central tendency and dispersion. Result shows that 59.64%, 50.45% and 17.02% of the drive test route for Airtel, 9mobile and MTN network had good signal quality and met with the Nigerian telecommunication regulatory benchmark of at least -9dB for Ec/Io. Also, 40.36%, 49.55% and 82.98% of the drive test area for Airtel, 9mobile and MTN network fell below the regulatory benchmark and subscribers in this region experienced dropped calls, blocked calls, handover failures and degraded signal quality due to interference. Airtel network was adjudged the best network while the worst network was MTN network. The result provided by this article will help radio network engineers operating in Calabar South and Calabar Municipality, to efficiently reuse limited frequencies, avoid interferences, optimize handover and adjust transmitted power level. The mobile network operators are advised to build new base stations and visit the existing ones regularly for optimization.