Turk J Elec Eng & Comp Sci (2015) 23: 548 – 559 c ⃝ T ¨ UB ˙ ITAK doi:10.3906/elk-1302-191 Turkish Journal of Electrical Engineering & Computer Sciences http://journals.tubitak.gov.tr/elektrik/ Research Article Quali ty of serv ice assessment: a case study on performance benchmar king ofcellular network operators in Turkey Rana KADIO ˘ GLU 1 , Yaser DALVEREN 2 , Ali KARA 2,∗ 1 Roll-Out Management-Central Anatolia, Vodafone, Ankara, Turkey 2 Department of Electrical and Electronics Engineering, Faculty of Engineering, Atılım University, Ankara, Turkey Received: 26.02.2013 • Accepted: 17.04.2013 • Published Online: 23.02.2015 • Printed: 20.03.2015 Abstract:T his paper presents findings on p erformance benchmarking of cellular network operators in Turkey. Bench- marking is based on measurements of standard key performance indicators (KPIs) in one of the metropolitan cities ofTurkey, Ankara. Performance benchmarking is formulated by incorporating customer perception by conducting surveys on how import ant KPIs are from the user’s point of view. KPIs are measured, with standa rd test equipmen t, by drive test method on specifi ed routes. Accord ing to the performa nce benchmar king result s, the GSM and UMTS netwo rk operators achieving the best performance were determined in Ankara. Speech qualities of network operators, as the most popular service, were also evaluated by several statistical methods including pdf/cdf analysis and chi-square and Fisher’s exact tests. The netw ork operator provid ing the highest speech quality in Ank ara was dete rmine d with the methods applied. Overall, the resul ts and approac hes on benchmarki ng of cellu lar networks in T urk ey are report ed for the first time in this paper. The approa ches propose d in this paper could be adapt ed to wide -scal e b enc hmark ing of serv ices in cellular networks. Key words: Cellular networks, benchmarking, key performance indicators, speech assessment, quality of service 1. Introduction Cus tomer sat isf action is cri tic al to gai n a sus tai nable competi tiv e edg e in the market. In communic ati on networks, as the customer’s satisfaction with the service is directly dependent on the quality and the performance of the network, measurements of network performance and quality of service (QoS) assessments are crucial [1– 7]. For this purpose, net work operato rs should surv ey the performanc e of their net work s and measure quality parameters on a regular basis as customers’ needs and satisfaction are presumably the main market driver, and especially in wide-area service networks such as cellular communications networks [8]. Generally , network optimization engineers exert efforts to increase the quality and capacity of operational networks, and to develop and deploy new ser vic es in ord er to mee t cus tomer demands and to guaran tee custo mer satis fac tio n. Key performance indicators (KPIs) are universally accepted parameters of cellular networks that engineers need to survey and keep within some specified threshold values in order to meet the QoS criteria required by both competent authorities and customers [8–10]. On the other hand, benchmarking is a comparison of a company’s network performance with their competitors’ and/or a comparison of its performances measured at different periods in time. In other words , bench marki ng is a kind of assessment of the service qualit y of an operation al network [11]. ∗ Corres pondenc e: aka ra@atil im.edu.tr 548
