Modeling and allocation of connections in next-generation wireless networks.

摘要

This dissertation (1999–2002) is about the modeling and allocation of wireless connections in next-generation mobile environments such as cellular networks and wireless ATM. In practical mobile systems the connections could also be called ‘calls’. The main contents of this dissertation consist Of five components as follows: (1) This dissertation proposes a novel wireless ATM framework in order to meet media-flows' end-to-end quality-of-service (QoS) requirements in wireless multimedia systems. Our suggested architecture is based on a multiple-layer implementation. (2) With the wide-spreading use of wireless Internet, it is very meaningful to develop detailed analytical models of the wireless TCP congestion control. This dissertation proposes a hybrid model to capture any size of wireless TCP connections with un-TCP traffic. Meanwhile the ns-2 simulation tool is utilized to verify the validity of our proposed hybrid model. (3) To further extend the abovementioned hybrid wireless TCP model to a correlated-wireless-loss case, this dissertation adopts Finite-State Markov Channel (FSMC) model as the basis of link error definition since in typical cases it is not adequate to model a radio communication channel only as a two-state Gilbert-Elliott channel. (4) To guarantee the connection-level QoS, i.e., minimizing the dropping rate of handoff calls while controlling the blocking rate of new calls, this dissertation proposes an optimal scheme for accepting new calls based on efficient dynamic channel reservation. For optimizing the utilization of wireless bandwidth resources, this dissertation presents a practical method of determining the percentage of guard channels that can be used by new calls during congestion. (5) The effective delivery of Multimedia will become an increasingly important issue. To provide the guaranteed mobile QoS for arriving multi-class calls, a new multi-class call admission control mechanism is proposed which is based on dynamically forming a reservation pool for handoff requests.