Bachelor Thesis Electrical Engineering June 2011. A Quantitative Study of Quality of Experience (QoE) for Decreasing and Increasing Network Performance. Ramesh Dhungana (830825-9731) Deepak Shahi (890830-1396) Internet : www.bth.se/com School of Computing Phone : +46 455 38 50 00 Blekinge Institute of Technology Fax : +46 455 38 50 57 371 79 Karlskrona Sweden. 1 Contact Information: Authors: Ramesh Dhungana Address: Lindblomsvagen 98, 372 33 Ronneby, Sweden. E-mail: [email protected] Deepak Shahi Address: Lindblomsvagen 98 372 33 Ronneby, Sweden. E-mail: [email protected] Thesis Examiner: Dr. Markus Fiedler School of Computing, Blekinge Institute of Technology, Karlskrona, Sweden. Email: [email protected] Thesis Supervisor: Charlott Lorentzen School of Computing Blekinge Institute of Technology, Karlskrona Sweden. E-mail: [email protected] 2 ABSTRACT Currently, user satisfaction is becoming one of the major concerns for the service provider in accommodating user demand. This paper evaluates the user’s perception (Quality of Experience, QoE) of the increasing and decreasing response times (Quality of Service, QoS), in particular a login to web login page by the implementation of Mean Opinion Score (MOS). By comparing the results to user perception of web login performance, we show that the users perceive web login for increasing and decreasing RTs in different ways. So, we conduct interview among specific users applying increased and decreased RTs in particular web login to rank the users satisfaction level. Study of the two results for RTs of the web login page is presented. Keywords: Quality of Experience (QoE), Network Performance, User perception and Response Time. 3 ACKNOWLEDGEMENT We would like to express deep and sincere gratitude to our Supervisor Charlott Lorentzen for her excellent guidance and encouragement which led us to the completion of our thesis. It would not have been possible our thesis without her support and guidance. We also would like to special thank to our thesis examiner Markus Fiedler for his invaluable suggestion and co-operation which helped us to deal with the research matter seriously, otherwise it would have been more difficult. We are also thankful to our friends and families for their inspiration, support and encouragement to complete our thesis. Last but not least, we have been very grateful and thankful to the Blekinge Institute of Technology for providing us the comprehensive education which will be definitely fruitful in forthcoming days to open the doors of opportunities in our career. 4 Table of Contents 1 INTRODUCTION ......................................................................................................................................................... 7 1.1 BACKGROUND ................................................................................................................................................................ 7 1.2 MOTIVATION .................................................................................................................................................................. 7 2 TECHNICAL BACKGROUND ................................................................................................................................... 9 2.1 QUALITY OF EXPERIENCE (QOE) .................................................................................................................................... 9 2.2 PHP .............................................................................................................................................................................. 10 2.3 WEB LOGIN PAGE ......................................................................................................................................................... 11 3 METHODOLOGY ...................................................................................................................................................... 12 3.1 QUANTITATIVE ............................................................................................................................................................. 12 3.2 QUALITATIVE ............................................................................................................................................................... 13 3.3 DATA COLLECTION ....................................................................................................................................................... 13 4 DATA ANALYSIS....................................................................................................................................................... 14 4.1 QUANTITATIVE ANALYSIS ............................................................................................................................................ 14 4.2 QUALITATIVE ANALYSIS .............................................................................................................................................. 19 5 DISCUSSION ............................................................................................................................................................... 20 6 CONCLUSION AND FUTURE WORK ................................................................................................................... 22 7 REFERENCES ............................................................................................................................................................ 23 5 LIST OF ACRONYMS BTH Blekinge Institute of Technology ISP Internet Service Provider ITU International Telecommunication Union MOS Mean Opinion Square OS Opinion Score PHP Hypertext Preprocessor QoE Quality of Experience QoS Quality of Service RT Response Time WWW World Wide Web 6 1 Introduction 1.1 Background While communicating web authentication technology, QoE has been major issues on the performance of network service. More precisely, it is often hard to correlate network- level quality of service to the QoE perceived by users for any web application. Ranking user perception itself is a complicated phenomenon which is influenced by different objective (network quality, device capacity) and subjective parameters (expectations, emotion and location). These parameters also help to detect service QoE degradation and suitable action to restore better network quality. From the user point of view, users do not know what delay is but the users notice the effect of delay in data network for network performance [2]. Research on the area of QoE for analyzing network performance has been done in different ways but there is no much work on this area for comparative analysis of increasing and decreasing RTs. So, in our thesis we aim to investigate the QoE estimation for increasing and decreasing RTs. 1.2 Motivation However, defining and measuring QoE is a challenge and involve interdisciplinary research. There are many influencing factors that come on the way when QoE is discussed. The ITU-T recommendation G.1010 [9] states the parameters and how they affect user perception with regards to RT and packet loss. ITU-T recommendation G.1030 [1] provides the result in reference to subjective responses from different type of users for RT while they are having access to web browsing sessions. According to ITU-T recommendation G.1030 [1], it also has been meaningful to understand the user expectation and the service which user received QoS. Likewise, in G.1010 [3] a relationship between packet loss and QoE, on user perspective by using MOS has been studied in the context of voice application. The research is going on the area related to user perceived experience, quality issues and its application. To the best of our knowledge, there are no study that compares the variations in user experience between increasing and decreasing RTs with different participants. So, this topic has been the main motive towards this thesis. The main objective of our thesis is to evaluate user satisfaction level between increasing and decreasing RTs of web login page. User perception is judged according to the service utility, the usage of service by users. This usage might be influenced by network performance. If the users get better service, it motivates them to use the service in future, if not they might give up service because of bad network behavior which reduces service utility. Excessive waiting times imply the risk of users 7 leaving service. Hence service utilization and service performance are strongly dependent on each other in the context of users [11]. In this thesis, our aim is to find the variations in user satisfaction level between increasing and decreasing RTs of web login page, how it is subjectively ranked by the users. This thesis presents the variations on the changing user behavior at different RTs and discusses the correlation of the subjective grading of the login page by the users with different RTs. The hypothesis that has been used in our research is: “variation of user’s satisfaction level for increasing response time which can’t be same as variations in decreasing response time”. The scope of the research is limited to the study of variations in two cases, one for increasing and decreasing RTs. We are supposed to expect the following results. 1. How does user’s satisfaction level between increasing and decreasing RTs become similar in a web login? 2. How does users’ satisfaction level become different for increasing and decreasing RTs in a web login? The organization of this thesis is as follows: section