An Assessment of Quality of Service (QoS) In Voice Communications over Four GSM Networks in Lagos and Oyo States of Nigeria

This study investigated the performances of four operators of mobile telecommunications services in voice communications in Lagos and Oyo States in South Western Nigeria for the first five years of operation. Using the International Telecommunications Union (ITU) standard of measuring customer experience of voice telephony service through the voice quality scores known as the Mean Opinion Score (MOS), the study identified the quality of service in voice call between the year 2001 and 2006. The data used for the statistical analysis were obtained randomly from the subscribers of GSM services in the states. The research established that the voice quality for the first five years of operation on all the networks considered were below the ITU specified conversational voice quality of > 3.0 on the MOS scale.