| In this thesis, we examine the multi-class admission control problem in a mobile wireless environment. Users originate in a particular cell and may migrate over the period of the call to other cells in the network. Each traffic class in the network has its own quality of service (QoS) requirements which include both call and handoff dropping probabilities and a call blocking probability profile and its own properties including call length, mobility characteristics, and bandwidth requirements. We introduce two sets of QoS performance measures which are used to evaluate performance. They require that users of each traffic class are not dropped during service with appropriate probability and that different traffic classes are blocked based on a pre-determined profile.; We explore three different approaches, the first of which is static and the others of which are dynamic, to solve the problem.; The first algorithm is a static reservation-based approach. It is a multi-dimensional generalization of the trunk reservation algorithm. It reserves a fixed number of basic bandwidth units (BBUs) for each traffic type and does not adapt to changes in traffic composition or load. At low loads, it performs similarly to the complete sharing (CS) algorithm which maximizes throughput. It also improves over the complete partitioning (CP) algorithm. At high loads it outperforms both the CS and CP algorithms.; The second approach is based on a one-step prediction mechanism. Decisions are made autonomously in each cell based on the current occupancy levels of the different traffic classes in each of the home and neighboring cells. The algorithm family contains several different variants which we analyze. The algorithms provide guarantees on the maximum probability of being dropped on handoff independent of load or traffic composition.; The third approach is a completely distributed measurement based algorithm. Partitions in each cell are periodically updated based on measurements of the call and handoff statistics in the cell to conform to the pre-specified requirements. New and handoff partitions are adjusted independently leading to both improvement in performance and algorithm simplicity.; Simulation results and analysis and comparison to other algorithms where appropriate are used as performance benchmarks. |
