ABSTRACT
In GSM communications, congestion remains a major factor and stands as a high influence in the satisfaction of subscribers and service providers [1]. Traffic Channel (TCH) and Standalone Dedicated Control Channel (SDCCH) Congestions are two major problems faced in GSM networks. This thesis attempted to investigate the causes of SDCCH & TCH congestions, and the assessment of the current state of GSM networks in Nigeria by using a Nigerian GSM network‟s KPI (key Performance indicator) as case study to develop an optimized GSM network model.
During the sampling and processing of the data in the investigation, a range of 49-0% was chosen as the worst call setup success rate (WCSSR). These WCSSR locations along with their various SDCCH & TCH congestion results were later plotted into bar chart graphs, and point graphs using OriginPro software. Finally, a Sugeno-Takagi KPI Optimization simulation setup was developed using Adaptive Network Fuzzy Inference System (ANFIS) model in MATLAB. The simulations compares and demonstrates the current and expected optimized network. The result shows that optimization is possible and can be almost at the maximum level in real cellular networks.
CHAPTER ONE
INTRODUCTION
• Introduction GSM
Global system for mobile communications (GSM), a digital cellular radio network, uses more advanced technology and handles more subscribers than the analogue cellular network due to the use of Time Division Multiple Access to divide the channel in time. High quality voice communication and low bandwidth (96kb/sec) data connections for fax and Short Message Service (SMS) are offered [2].
GSM communication aims to give communications anytime and everywhere between objects. GSM Network, usually called „‟cellular network‟ (as the whole coverage area is divided into different cells and sectors), is comprised of a mobile Station (MS) which is connected to the Base Transceiver Station (BTS) through air interface [3]. In addition to other hardware, BTS contains the equipment called Transceiver (TRX), which is responsible for the transmission and reception of several radio frequency (RF) signals to/from the end user. BTS is then connected to the base station controller (BSC) through abis interface. The BSC is connected to the Mobile Switching Centre (MSC) and usually handles handovers of the calls from one BTS (or cell/sector) to the other BTS (or cell/sector) equipped in it and radio resource management [3].
• Background of the study
The mobile industry in Africa is booming. With over 620 million mobile connections as of September 2011, Africa overtook Latin America to become the second largest mobile market in the world, after Asia and the fastest growing mobile market in the world. (New GSMA
Africa Mobile Observatory 2011 Report). GSM is one of the most demanding and wildest growing of all wireless mobile telecommunication technologies [4]. According to the Nigeria Telecommunication Authority, GSM communication is the major, fastest, and simplest means of telecommunication in Nigeria. Family, friends, business partners and others use mobile communications to quickly get messages across to each other locally and internationally but; there are major problems faced with the Quality of services. GSM services like emails, browsing, voice, video streaming and all multimedia demands on mobile telephone have and are still increasing tremendously. As more people subscribe to GSM network services due to the many features available, the issue of congestion on the GSM network also tends to escalate [5]. GSM networks have to deliver what these services demand, so that the performances and the user‟s satisfaction will be satisfactory. Standalone Dedicated Control Channel (SDCCH) Congestion and Traffic Channel (TCH) Congestion are two of the many problems faced in all GSM Networks in the quest to satisfy subscribers. When these channels are congested, successful call setup success rate (CSSR) will be at a minimum level leading to worst call setup success rate which will be at a high level. On the other hand, when there are less SDCCH & TCH congestions in a network, operators tends to generate more income from subscribers, subscribers have better quality of services, and vice versa. In order to keep subscribers, the Quality of Service (QoS) of a network should be very good that is, GSM operator‟s networks should be almost congestion free. Customers may decide to change their network at anytime due to high charges or most especially poor quality of Service (QoS). Operators may suffer greatly if there are congestions in these channels. The more a network is optimized, the better the quality gets, the more subscribers will be added to the network, and more incomes will be generated. Subscriber‟s satisfaction and generating incomes are two main reasons an operator should optimize his network.
• Problem Statement
From several interactions with subscribers, service personnel, mobile network engineers, and self-observations over the years, in different cities and different GSM networks in Nigeria; delays in text, voice, and setting up calls have been major issues with networks. Subsequently with network coverage, subscribers usually receive signs of “Network Busy” that is, when a subscriber dial a number to call, the call don‟t go through but instead drops for redial. This also happens when trying to send message. Subscribers notice that even with network coverage, messages takes time to send. This inspired the current research to particularly look into SDCCH and TCH congestion in order to improve the mobile communication sectors in Nigeria.
Over the years, GSM services across the country have changed positively. Its explosive growth has brought huge revenues both to the operators, subscribers, as well as the government through taxations, license fees and fast businesses. Similarly, citizens and non- citizens have benefited incalculably from those services, not only as a means of communication but; it has provided job opportunities for many people [6]. Nevertheless, the main development that spoils these benefits, are the fast-growing grievances raised by GSM subscribers regarding, quality of services (QoS) rendered by the GSM operators within the country. The unfortunate aspect of this is; the fact that, most GSM subscribers, regardless of the operator, are being affected. In Nigeria, GSM subscribers/customers major complaints have been the delay in call setup, voice & text.
• Objectives of study
• The study intends to investigate the causes of SDCCH and TCH congestions in GSM networks.
• To assess the current state of Nigeria‟s GSM networks in relation to SDCCH and TCH congestion.
• To offer likely solution(s) that will reduce the problems associated with SDCCH and TCH congestions in Nigeria‟s GSM network.
• Significance of study
In GSM, the best way to get more subscribers, and keeping them satisfied, is to make the service as easy to use and very reliable [2]. In this research, the main significance is to evaluate and minimize the SDCCH (Stand Alone Dedicated Control Channel) and the TCH (Traffic Channels) congestions in Nigeria GSM(s) so that the Network accessibility, service retain- ability, connection quality and network coverage will be almost at a maximum level for the satisfaction of Nigeria GSM‟s subscribers, and the generating of more revenues for the operators.
• Organization of study
The standpoint of this thesis is as follows: The first chapter provides an introductory summary, research motivation, problem statement, objectives and structure of the work. Chapter two presents an overview of the GSM Network, discusses the various channels in a GSM network, optimization of GSM networks, types of optimization and summarizes related works similarly done in this area of study. In Chapter three, Methodologies employed in this research are introduced. Chapter four examines the expected findings and result(s) of the study. In chapter five, conclusion and recommendation(s) that will be of great help to GSM operators and subscribers are provided. This could also lead to further research in the area of study.
================================================================
Item Type: Project Material | Size: 62 pages | Chapters: 1-5
Format: MS Word | Delivery: Within 30Mins.
================================================================
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.