Mr. Khaja Kamalluddin

Mr. Khaja Kamalluddin, an instructor in the Computer Science Department, Dhofar University gave a seminar entitled “Dynamic Bandwidth Reservation for Multimedia Handover Calls In Wireless Mobile Cellular Networks” on the 30th of April, 2007 in Ibn Rushd Hall. He said at the beginning of his presentation that due to the increase in demand for accommodation of a larger number of users, the cell size in mobile wireless cellular networks is being reduced. Consequently, bandwidth in each cell has become limited. Due to the decrease in cell size, a larger number of handovers take place. If bandwidth allocation to these handover calls is not carried out properly then the dropping probability of handover calls will be increased. Also, if sufficient bandwidth is not available for new calls, there is an increasing probability of the blocking of newly generated calls. Dropping of handover calls is relatively less desirable than the blocking of new calls. Many alternative solutions have been proposed to solve the problem in resource allocation. However, presently available solutions are not enough to provide and maintain QOS (Quality of Service) for multimedia handover calls.
    In this paper Mr. Kamalluddin proposed the GPS (Global Positioning System) based handover mechanism. This will reserve bandwidth in one cell and avoid unnecessary reservations at many neighboring cells. Also, he proposed the usage of the sliding bandwidth window method for bandwidth reservation and allocation to handover calls. In this method, bandwidth window size changes according to network traffic conditions and is maintained flexible in changing its size. Based upon the expected number of handover calls, the window size changes its capacity so that more handover calls can be accommodated. In order to maintain QoS (Quality of Service) for multimedia handover calls, the focus, in this paper, is to allocate required bandwidth to this call. For lower priority handover call (data call), at least minimum bandwidth will be allocated in a worst-case scenario. At the same time, they maintain the balance with locally generated calls in allocation of bandwidth. In this method dropping probability of handover calls is reduced to minimum and blocking probability of new calls is also minimized.