CONGESTION CONTROL MECHANISMS IN GSM TELECOMMUNICATION NETWORKS (THE CASE OF MTN NIGERIA)

ABSTRACT Congestion remains a major challenge to telecommunications service provision both to the service providers as well as the subscribers. This seminar work attempted to determine the causes of congestion and evaluated congestion control mechanisms adopted by service providers in Nigeria using MTN Nigeria as a case study.  Findings from the study showed that apart from the carrying capacity of the MTN network other factors such as the use of phones for data transfer and multimedia activities contribute to traffic congestion on the network. Other external factors such as vandalization of network equipment, weather and high rise buildings also contributes negatively in varying degrees to service sustainability.
WHAT IS CONGESTION? As Defined by Kuboye (2010), Congestion is the unavailability of network to the subscriber at the time of making a call. Congestion occurs when there are limited resources at the service point, this leads to queues, called traffic or congestion. It is the situation when the blocking occurs and no free path can be provided for an offered call. That is, when a subscriber cannot obtain a connection to the wanted subscriber immediately. The ideal telephone system is a situation where it is possible for all subscribers to talk in pairs simultaneously. If one connecting device be allocated for a pair of subscribers, then the number required will be too high to be reasonable. Such an ideal system is impracticable because of its enormous size, very high cost and maintenance difficulties. It is therefore necessary to reduce the number of connecting devices which means that the subscribers are confronted with the possibility that some of their calls may be unsuccessful. The reduction in number of connecting resources consequently leads to reduction in the number of conversation which can take place simultaneously. 
CAUSES OF CONGESTION Congestion is the unavailability of network to the subscriber at the time of making a call. It is the situation when the blocking occurs and no free path can be provided for an offered call. It manifests in various ways, hence it is usually an everyday experience. It therefore, makes an economic sense for congestion to occur because naturally, in every real world situation resources most time are limited and it is necessitated by an unequal relationship between services required and the facilities used for rendering the service. Congestion often results in queues. Queuing is seen as a line of things or people waiting to use a particular resource. For instance, a traffic jam usually occurs when there are many vehicles prying a road at the same time. The road will be filled (congested) with vehicles that are moving in succession. This scenario is replayed almost in every human activity. However, congestion is not restricted to human activities as it could also take place in data transmission. Congestion in signaling network may well be the visible symptoms caused by signaling traffic being redirected due to failure of the network component, (Lars, et al 2001) and (Stefan, and Ake, 2002). Congestions are more likely to arise from traffic redirections at network component failure or by an extremely high call density to one specific node. Congestion inhibits the normal flow of data signals thereby resulting in these signals queuing up in order to be allocated resources by the server. The time it takes these signals to wait in the queue is a determinant of the capacity of the server. The capacity of the network equipment, literally, has been the number of data signals a system can handle.