Abstract
M.Tech. (Electrical Engineering)
Wireless communications have experienced massive development remarkably in the past decade. Networks such as global system for mobile communications (GSM) and universal mobile telecommunication service (UMTS) has enjoyed enormous patronization, hence leading to massive mobile network congestion. The problem of network congestion is a network managerial issue that affects the Quality of Service (QoS) rendered by a network. Hence for the sustainability of the system, there is a need to fully manage the radio resources during peak and off peak periods.
Call Admission Control (CAC) schemes are constantly being used extensively in managing mobile network congestion. CAC is an approach that can provide credible QoS by regulating the number of connections into the cellular network thereby allowing good use of the radio resources, reducing network congestions, interference and other QoS problems. Network resources cannot be available for all users at all times especially during busy hour traffic. Hence, these resources require effective and efficient allocation so that more subscribers are being allowed to use the network irrespective of the network traffic at a particular reference time.
Mobile network congestion can be controlled by suppressing the mobile network traffic demand. The traffic demand varies proportionally with average rate of call arrival and the average duration of the calls. Hence marginalizing the average call duration will minimize traffic load, thereby reducing network congestion. Some network users due to their lifestyle of being affluent or business demands, holds on to a particular channel during long duration of calls at the detriment of other network users. CAC scheme cannot solve congestion problems due to the selfishness of these particular sets of users. Here, the combination of a channel reservation CAC scheme with Call Duration Control (CDC) scheme was proposed, in which users that have stayed over a predetermined period in the network will be served a termination notice so as to make the channel available for new users. The motive is to provide the available channels to accommodate more users.
A simulation-based approach was used to model the combination of the two schemes and the combination produces good results in reducing the congestion menace. The network type deployed in the research is GSM. The result of the CAC/CDC combination schemes were compared to the result of the ordinary CAC schemes in order to verify the impact of the...