The voice only service has rapidly been making way for the packet switched multimedia services. In a cellular mobile system, multimedia services will soon be the mainstream ones, the pace of which is expected to be quantum-jumped by the 3G system. In this Ph.D dissertation, we analyze three problems of operation management and network design for WCDMA systems, the most promising 3G candidate system.
First, we propose an optimal setup of interference thresholds. The cell capacity of a CDMA system is mainly determined by the sum of interferences generated by call connections. Focusing on downlink interferences in a WCDMA system, we address a threshold-type call control scheme. Finding the characteristic pattern of an expected cell-throughput, we formulate a mathematical program maximizing the system throughput. The solution shows the optimal interference threshold value for each cell, which also demonstrates the effects of allowing differences in thresholds among cells.
Next, we address call access control in the WCDMA downlink common channels. Proposed is a policy consisting of two phases, the first screening calls for admission, and the second scheduling call services according to the most popular preemptive FIFO rule. The scheduling mechanism is first depicted on the infinite vertical time-strip with width representing the aggregate capacity of common channels, by denoting a call service as positioning the corresponding call-rectangle thereon. Enabled by this depiction, we apply the existing results on the two dimensional bin packing problem in projecting the sojourn time of an arriving call. The first phase of call admission control is based on the projections, from the characteristics of which calls, once admitted, are guaranteed to be serviced within allowable delay. The performance of the proposed access control policy is extensively tested with realistic input data. The results are found convincingly affirmative for its practical applicability.
Finally, w...