CHAPTER ONE 
INTRODUCTION 
1.1    BACKGROUND OF THE STUDY 
The world is fast becoming a global village and a necessary tool for this process is communication of which telecommunication is a key player. The quantum 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 telephone lines or the Global System of Mobile Communications (GSM). Communication without doubt is a major driver of any economy. Emerging trends in socio-economic growth shows a high premium being placed on information and communication technology (ICT) by homes, organizations, and nations. Nigeria is not left out in this race for rapid development as the nation’s economy has been subjected to years of economic reversal via mismanagement and bad leadership. The Nigerian telecommunications sector was grossly underdeveloped before the sector was deregulated under the military regime of General Ibrahim Babangida in 1992 with the establishment of a regulatory body, the Nigerian Communication Commission (NCC). So far the NCC has issued various licenses to private telecommunications operator. These include 7 fixed telephony providers that have activated 90,000 lines, 35 Internet service providers with a customer base of about 17,000. Several VSAT service providers are in operation, and have improved financial intermediation by providing on-line banking services to most banks in Nigeria. These licenses allowed private telephone operators (PTOs), to roll out both fixed wireless telephone lines and analogue mobile phones. The return of democracy in 1999 paved the way for the granting of GSM license to 3 service providers: MTN Nigeria, ECONET Wireless Nigeria which is now called ZAIN and NITEL Plc which is now called ZOOM in 2001 and later GLO.   
1.2     STATEMENT OF THE PROBLEM 
It has been observed that calls across different networks are always difficult to connect, at times diverted and also attract more cost. This creates room for users to be confused as how much is deducted from their call credits or are compelled to having multiple GSM lines. As the network increases, more users makes call across different networks and there is need to record the call time, call network, and line identification and be able to put calls across the networks with out much congestions. Transmission of calls requires at least two points, A and B (point-to-point; point-to-multipoint or multipoint-to-point). Consequently, the interconnectivity problem within Nigeria is simply stated as follows: 
1.    How can A and B, separated possibly by thousands of kilometers within Nigeria, transmit voice to each other without each having to be subscribers to the same operator? 
2.    More importantly, how can we ensure multi-user resource allocation such that if A is the originating consumer, it does not matter technologically (even if financially) which of ALL the other operators that B is a subscriber to, nor does it matter what type of transmission he or she is sending? 
3.    The transmission of calls with out much congestion in the network. This will form the bases for the project work.     
1.3     PURPOSE OF THE STUDY     
The purpose of this research work is to establish a transparent set of Interconnection Rules, which shall encompass at least the following requirements: 
* Every operator must allow all other operators full interconnection to its network at technically feasible and convenient points of interconnection, such that traffic may originate on one network and terminate on another, or otherwise pass across networks, without interference, signal deterioration, delay, congestion, or restriction. 
* To design software that will serve as a congestion control system for multi-user telecommunication networks.   
1.4     SIGNIFICANCE OF THE STUDY 
This study will help us to know the status of GSM network resource allocation in Nigeria with a view to knowing areas to be addressed for better performance. This research work will aid telecommunication companies in Nigeria to achieve the following: 
1.    Keep record of calls across the GSM networks. 
2.   Use Interswitch to put calls through to the right designation without delay, distortions or diversion. 
3.   Determine the calling network and receiving network and use this information for the purpose of interconnectivity tariffs. 
4.   Maintain a database of all registered GSM lines for all GSM communication companies.   
1.5     AIMS AND OBJECTIVES OF THE STUDY 
Basically the aim of this project work is to design and simulate a multi-user congestion control system for MTN.   
1.6     SCOPE OF THE PROJECT 
This research covers network connectivity and traffic control of MTN network in Nigeria. The system covers all forms of voice calls across the network. Both call identification, recording and network interconnectivity.       
1.7     CONSTRAINTS AND LIMITATIONS 
Some of the constraints encountered during this project design include the following: 
·      Financial Constraints: The design was achieved but not without some financial involvements. One had to pay for the computer time. Also the typing and planning of the work has its own financial involvements.  However, to solve the problems I solicited fund from guardians and relations. 
·      High programming Technique: The programming aspect of this project posed a lot of problematic bugs that took me some days to solve. Problems such as the ADO, DAO and Jet Engine related run time errors. For instance, the Ms Access office 2000 edition does not work with VB-6. Jet Engine unless converted to lower version of Ms ACCESS of office 1997 edition (i.e. version 2.0). Also other technical problem, which requires semantic and syntactic approaches where encountered as well. In seeking for the solution to these problems, I acquired more knowledge from well –versed textbooks and programmes. 
·     Power Supply: The epileptic nature of power supply cannot be overlooked.     
1.8     DEFINITION OF TERMS 
Inter-switch: Inter-Switch Link (ISL) is a trunking method developed by Cisco to use for Ethernet and Token Ring trunk connections. 
Congestion: It is the overcrowding of route, leading to slow and inefficient flow. In computing, it is a situation in which the amount of information to be transferred is greater than the amount that the data communication path can carry. 
Air interface: In a mobile phone network, the radio transmission path between the base station and the mobile terminal.
Asymmetric Transmission: Data transmissions where the traffic from the network to the subscriber is at a higher rate than the traffic from the subscriber to the network. 
SIM: Subscriber Identity Module; A smart card containing the telephone number of the subscriber, encoded network identification details, the PIN and other user data such as the phone book. A user’s SIM card can be moved from phone to phone as it contains all the key information required to activate the phone. 
Telecommunication: Are devices and systems that transmit electronic or optical signals across long distances. Telecommunication enables people around the world to contact one another to access information instantly, and to communicate from remote areas. 
Computer Network: It is a system used to connect two or more computers using a communication link.