Evaluation and Comparative Analysis of the Quality of Service of GSM and CDMA Cellular Networks

Evaluation and Comparative Analysis of the Quality of Service of GSM and CDMA Cellular Networks in Zaria

ABSTRACT

The research was focused on evaluation and comparative analysis of the QoS of some selected GSM (Globacom and Zain) and CDMA (Starcomms and Visafone) networks in Zaria. Data for the purpose was collected for both intra and inter calls from ten different areas in Zaria by call centre Operators and the researchers, where a total of eight thousand nine hundred and sixty (14 days x 10 different areas x 4 times x 16 call combinations) calls were made.

The averages of each day were found and recorded in tables and used for analysis. The daily trend for each KPI for each network type and data collection site was shown using line graphs while the comparison of GSM inter and intra networks as well as CDMA inter and intra network for the KPIs (Key Performance Indicators) under study was shown using bar charts.

The work therefore revealed that GSMs operators’ performance in Zaria is better than the CDMAs and at the same time Globacom’s performance is better than Zain’s while Starcomms is better than Visafone. It also showed the most preferable network for each data collection site.

Mean while the values gotten for the KPIs were just closer or very slightly above most of those of the set standards. The conclusion was drawn and recommendations made. All the works of other authors were fully referenced.

TABLE OF CONTENTS

Title Page . . . . . . . . . . i
Dedication . . . . . . . . . . ii
Declaration . . . . . . . . . . iii
Certification . . . . . . . . . . iv
Acknowledgment . . . . . . . . . v
Table of Contents . . . . . . . . . vi
Abstract . . . . . . . . . . xi
Definition of Terms . . . . . . . . . xii
CHAPTER ONE: INTRODUCTION
1.0 BACKGROUND OF THE STUDY . . . . . . 1
1.1 MOTIVATION . . . . . . . . 3
1.2 STATEMENT OF PROBLEM . . . . . . 4
1.3 AIMS AND OBJECTIVES . . . . . . . 4
1.4 SCOPE OF THE STUDY . . . . . . . 5
1.5 SIGNIFICANCE OF THE STUDY . . . . . 5
1.6 CHALLENGES OF QUALITY OF SERVICE . . . . 6
CHAPTER TWO: LITERATURE REVIEW
2.0 INTRODUCTION . . . . . . . . 7
2.1 OVERVIEW OF MOBILE TECHNOLOGY . . . . 17
2.1.1 Mobile Station . . . . . . . . 17
2.1.2 Base Station Subsystem . . . . . . . 18
2.1.3 Network Subsystem . . . . . . . . 19
2.2 The Security Services Provided by GSM . . . . . 20
2.2.1 CDMA Architecture . . . . . . . . 21
2.2.2 Authentication and Security in CDMA . . . . . 22
2.3 DIFFERENCES BETWEEN GSM AND CDMA NETWORKS . . 23
2.3.1 Subscriber Identity Module (SIM) Card . . . . . 23
2.3.2 International Roaming with GSM and CDMA . . . . 24
2.3.3 Data Transfer Methods in GSM and CDMA . . . . 24
2.3.4 Interaction between GSM and CDMA . . . . . 24
2.3.5 Popularity and Market Share . . . . . . 25
CHAPTER THREE: METHODOLOGY
3.0 INTRODUCTION . . . . . . . . 26
3.1 MATERIALS . . . . . . . . 27
3.2 PROCEDURE . . . . . . . . 28
3.2.1 QUALITY OF SERVICE. . . . . . . . 29
CHAPTER FOUR: DATA PRESENTATION AND ANALYSIS
4.0 INTRODUCTION . . . . . . . . 30
4.1 SERVICE ACCESSIBILITY . . . . . . 30
4.2 SET UP TIME TELEPHONY . . . . . 47
4.3 CALL SETUP SUCCESS RATIO (CSSR) . . . . 67
4.4 CALL COMPLETION RATE TELEPHONY (CCR-CS-T) . . 84
4.5 PERFORMANCE OF INDIVIDUAL NETWORK IN EACH DATA
COLLECTION AREA . . . . . . . 101
4.6 GENERAL TABLE FOR INTRA AND INTER CONNECTIONS FOR ALL THE
GSM AND CDMA KPIs UNDER CONSIDERATION . . . 112
4.7 COMPARISON OF GSM AND CDMA CALLS FOR KPIs UNDER
CONSIDERATION . . . . . . . . 117
CHAPTER FIVE: SUMMARY, CONCLUSION AND RECOMMENDATIONS
5.1 SUMMARY . . . . . . . . 119
5.2 CONCLUSION . . . . . . . . 121
5.3 RECOMMENDATIONS . . . . . . . 121
REFERENCES
APPENDIX

CHAPTER ONE

INTRODUCTION

1.0 BACKGROUND OF THE STUDY

Communication is the backbone for the development of every society. Messages have to be exchanged from one person or one medium to another. The world is fast becoming a Global village and a necessary tool for this process is communication, of which wireless telecommunication is a key element. Wireless ad hoc networks are formed by a group of mobile users or devices spread over a certain geographical area.

The users or devices forming network “nodes”. Mobile networks have increased applicability in areas of military application such as sensor networks, tactical networks and positional systems Mobile networks have increasing applicability in Law enforcement.

Various law enforcement agencies use Mobile networks to communicate with each other, to track movement of criminals and to spy on criminal activities Video conferencing in some situations where there is no network infrastructure can be done

using networking which enables mobile on the spot conferencing.

Quality of Service has been defined by the United Nations Consultative Committee for International Telephony and Telegraphy (CCITT) recommendation E.800 as “The collective effect of service Performance which determines a degree of satisfaction of a user of the service”.

The Quality of Service is a rapidly growing area in both wired and Mobile Ad Hoc Network (MANET). Many problems exist especially for MANETs (Uma and Padmavathi 2009). They also stated that Quality of Service in mobile ad hoc networks depends not only on the available resources but also on the mobility rates of such resources. It means to provide a set of parameters to adapt the applications to the quality of the network while routing them through the network.

An ad hoc network as a dynamic type of Development in the telecommunications industry all over the world is very rapid as one innovation replaces another in a matter of weeks. A major breakthrough is the wireless telephone system, which comes in either fixed wireless lines or the Global system for mobile communication (GSM) (Wojuade, 2005).

Global System for Mobile telecommunication (GSM) and the Code Division Multiple Access (CDMA) are recent development that has come to stay so as to promote and ease the exchange of messages from one person or one medium to another.

According to Adomi, (2006) GSM is used by Nigerians mostly to communicate with one another. He explained that students used it to communicate with their course mates, friends, lecturers and relations. Additionally, family matters, finance, and academic matters constitute the topics/subject of mobile communication for a majority of students.

Mobile phones limit the need for students to travel as well as facilitating the exchange of information as the need may arise. It has helped to enhance computing on the move as services are rendered anywhere within the coverage area.

According to Patrick (2003) Quality of Service (QoS) is usually defined as a set of service requirements that need to be met by the network while transporting a packet stream from a source to its destination. The network needs are governed by the service requirements of end user applications.

The network is expected to guarantee a set of measurable pre-specified service attributes to the users in terms of end-to-end performance, such as delay, bandwidth probability of packet loss, delay variance (jitter) and many others.

Notwithstanding, for a mobile network telephony services specifically to be of quality, it has to meet up with some criteria such as Speech Quality, Call Completion Rate, Call Setup Success Ratio, Service Accessibility Telephony, Service Accessibility Short Message Service, and Access Delay Short Message Service. The services have to be delivered to the customers as at when needed, audible enough and without noise and other related hitches.

QoS is sometimes used as a quality measure, with many alternative definitions, rather than referring to the ability to reserve resources. Quality of service sometimes refers to the level of quality of service that is the guaranteed service quality (Wikipedia free Encyclopedia).

One of the aims of QoS is to manage the service response provided to low-speed devices such as mobile wireless devices. The QoS can be ensured only when the achieved/actual performance is greater than or equal to the desired performance.

With the growth of mobile services, it has become very important for an operator to measure the QoS and Quality of end-user Experience (QoE) of its network accurately and improve it further in the most effective and cost-efficient way to achieve customer loyalty and maintain competitive edge (David, 2006). The service provider must take steps to introduce new mechanisms to achieve the desired performance.

Otherwise, QoS cannot be achieved.

1.1 MOTIVATION

Time without number, many subscribers suffer one or two undue penalties ranging from denial of service, over charge, double charges or charges without services rendered. This falls in line with the lamentation of the columnist Emmanuel Tiko Okoye in Daily Independence (Lagos, 2009) who said “I sent a ZAIN Short Message Service (SMS) to the 230 number as directed.

I then checked my account balance and discovered that the sum of N100 (cost of SMS) had been deducted. 48 hours after the money was deducted the SMS was still Pending! It’s a double whammy for me: I was deprived the usage of N100 worth of talk-time and was also denied the opportunity to participate in one of my favorite TV shows!”

Sometimes it becomes difficult to connect two different networks successfully in such situations different information like “Network busy” , “The number you have dialed is not on the Globacom Network”, “Error in connection”, “No answer”, “Number busy and when the call goes through, the charge becomes higher or the Quality of Service is deplorable in its entirety.

Either the charges are done without a successful call or the voice quality is poor or another person’s voice (interference) is heard other than the intended callee. As a necessity each and every one has to enjoy it so as to ascertain the aim of which it is intended for and at a price relative to the services offered. It is alleged that GSM services and CDMA services also differ in terms of QoS.

1.2 STATEMENT OF PROBLEM

Due to the high demand of the services of mobile network operators many of them tend to render poor QoS. This is in line with the assumption that GSM services are better than those of the CDMA and vice versa. This work tried to provide answers to the following questions:

 Does QoS vary between GSM and CDMA networks for Intra and Inter network telephony services?

 Does GSM network have a better QoS than CDMA network for both intra and inter telephony services?

1.3 AIMS AND OBJECTIVES

This work is intended to:

– Evaluate and measure the QoS for both Intra and inter network telephony of GSM and CDMA networks under study from the users’ perspective.

– Determine the difference in Quality of Service (QoS) between GSM and CDMA network services in Zaria.

– Determine the mobile network operator with the best quality of service in Zaria.

– Determine the most preferable network for each data collection site based on the KPIs.

– Proffer suggestions where necessary.

1.4 SCOPE OF THE STUDY

This research was carried out on the evaluation and comparative analysis of the quality of service of the four major GSM and CDMA networks operators in Nigeria the situation in Zaria from the users’ perspective using manual/statistical means.

This embodies two GSM networks (ZAIN and Globacom) as well as two CDMA networks (Starcomms and Visafone). The research will be conducted locally by collecting data from some selected locations using calls made in Zaria, Kaduna state, at different base stations and transceivers especially where traffics are always high like on campuses of

Ahmadu Bello University, Samaru and Kongo campuses, Nuhu Bamalli polytechnic campus, Ameer Shehu, Idris College of Advanced Studies, Federal College of Education, Zaria, College of Agriculture Samaru and College of Chemical and Leather Technology, Samaru as the calling point to any other Base Transmission Stations (BTS) in the country as the callee points.

1.5 SIGNIFICANCE OF THE STUDY

This research will be of great significance to various mobile network stakeholders such as:

 Network Operators, it will help to determine the level and stand point of operation of the services they supply to the users.

 To the users it will help them determine which network is better for their use either financial wise or QoS wise.

 It will also give the government the insight of the standard and QoS of mobile networks and network types that prevail in the country and

 It will still enable academicians to go into more research on issues like the algorithms review and inventions that will lead to improvement and innovations in the general field of mobile networks in various parts of the country and the country as a whole.

1.6 CHALLENGES OF QUALITY OF SERVICE

In wireless mobile networks QoS refers to the measurement of a system with good transmission quality, service availability and minimum delay. In (Fourth Generation) 4G it is expected to have a reliability of at least 99.999 referred to as five nines reliability.

The major challenges when considering QoS in cellular networks are varying rate channel characteristics, bandwidth allocation, fault tolerance levels and handoff support among heterogeneous wireless networks. It is fortunate that each layer which includes physical, Media Access Control (MAC), Internet Protocol (IP), Transmission Control Protocol (TCP) and application have got their own mechanisms to provide QoS.

It is important to guarantee QoS in each layer so that the network is more flexible and tolerant to QoS issues. Some of the other challenges are efficient usage of the spectrum as its availability is limited. Bandwidth allocation plays a major role with respect to this aspect. It must be made sure that bandwidth is allocated in an efficient manner and also the remaining bandwidth should not be wasted (Monego, 2005).