Abstract: “The rapid growth of cellular networks in recent years results into the need of optimization of networks, so that they provide a better service to customer without any interruption. The needs of a Cellular operator include proper delivery of data and voice to the Mobile Stations or user equipments. Speech quality experienced by the end user can be regarded as one of the most significant quality aspects of mobile communication. This paper includes a review of the Key Performance Indicator (KPI) parameters based Speech Quality Index (SQI) in details that are used to enhance the ability of the cellular network to provide techniques to improve Quality of Service. Speech Quality methods can categorized based on measure and performance evaluation which motivate why speech quality measure is important and possible in given radio link status. SQI is technique that allows cellular network to provide measurement of speech quality that has applications from equipment installation to daily network”

Keywords: drive test (DT), key performance indicator(KPI), speech quality index(SQI)