International journal of Advances in Computer Networks and its Security 189 Measuring Parameters for speech quality in cellular networks 1 Rakesh Kumar, 2 Sandeep Saini 1, 2 Computer Science and Application Department, Kurukshetra University, Kurukshetra, India Email:sandeepsaini083@gmail.com 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 maintenance and benchmarking, it is an important contributing factor to the success of a product and to the success of the communication itself. Keywords— drive test (DT), key performance indicator(KPI), speech quality index(SQI) I. INTRODUCTION Monitoring and evaluating in cellular network is fundamental to the success of every cellular operator. Measurements help them to meet their Objectives. Key Performance Indicators (KPIs) is one important tool in the cellular network. KPI gives good indication of network performance. KPIs are organized data collecting and collating, where the Operator can monitor and evaluate their performance and drive for continuous improvements towards meeting their objectives.[1] Whereas Speech Quality Index is a method to measure and monitor the speech quality in the network based on radio quality information.[2] The use of SQI technology for Global System for Mobile (GSM) and Wideband Code division Multiplexing (WCDMA) is increasing, and there are compelling reasons to use this technology. SQI is a sophisticated measure which is dedicated to reflecting the quality of the speech. The speech quality on the uplink is determined by continuously monitoring the uplink radio conditions for each ongoing call in the network. The information element SQI, which we obtained estimates the speech quality in the cellular network as perceived by a human listener. In this paper we explain parameters for SQI algorithms for GSM. We can design the SQI algorithm for WCDMA in the same spirit, and its implementation is similar though necessarily not identical.[3] Speech quality in GSM networks is measured by means of the many parameters like RxQual, Bit Error Rate (BER), Frame Error Rate (FER) and L3 messages. Traditionally we use RxQual parameter to measure the speech quality, however, it suffers from a number of drawbacks which make it an unreliable indicator of speech quality.[4] There are two different measurements of speech quality in communication networks performed with intrusive and non-intrusive means.[6] A. Intrusive method: This method to measure speech quality is based on a comparison of both, original and transmitted signal using proper algorithm, e.g. International Telecommunication Union (ITU)-T P862 (PESQ). By using intrusive method it gives more accurate results in comparison with the quality assessed by the average listener that is acquired from listening tests. Due to high cost and time consumption, sometimes Intrusive method are not feasible and hence there is the need of Non-intrusive method. B. Non-intrusive method: The non-intrusive method estimates the quality just from the transmitted sample.[7] It is easy to see the difficulty of such an algorithm to give reliable results. Research into non-intrusive quality measurement usually entails comparisons between the test signal and normative behavior of clean speech, amongst other distortion-sensitive features.[8] The main advantage of the non-intrusive method is cost efficiency; the measurement is conducted within real