Browsing by Author "Wakijira, Fikadu"

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    New Bandwidth Allocation Scheme for Handover Voice Calls in Mobile Cellular Networks
    (Addis Ababa University, 2006-08) Wakijira, Fikadu; Ayele, Hailu (PhD)
    The demand of mobile communication has grown remarkably in past years. Mobile communication network (system) should use limited resources in efficient and convenient manner. One way of achieving this is to use smaller cells in the expense of the corresponding handover management and system administration overhead. The limited radio frequency spectrum available cannot be longer support the increasing number of mobile user, and user demand, and the required quality of service (QoS) no longer are attainable if a best solution is not found. The other simplest solution proposed to overcome this problem is to increase the network capacity, which is not economical and not really practical. The work in this thesis demonstrates the different types of channel allocation schemes and call admission control with handover management for voice call. This paper goes through the cellular capacity improvement: cell reuse, cell splitting cell tiering and cellular structure. Most of the proposed schemes in the literature give priority to ongoing (handover) calls on the expense of blocking the originating calls. We deem to introduce a new bandwidth reservation scheme based on guard channel policy. Accordingly, new calls are blocked if the amount of occupied bandwidth is greater or equal to a bandwidth threshold; Bt. The novelty of the proposed Time Threshold Based Scheme (TTBS) is based on the elapsed real time of voice handover call and according to a time threshold, Tr parameter, handover calls could be either prioritized or treated as new calls. The major contribution of this work is to exploit time threshold scheme to perform autonomous and intelligent negotiation to improve wireless resource allocation. We use simulation study to evaluate the performance of the proposed scheme. The TTBS scheme is simulated under different scenarios and the result show that, the proposed schemes provide good performance in terms of handover call dropping probability, new call blocking probability, and bandwidth utilization