Dynamic Bandwidth Management for TCP Flows in a Diffserv-Enabled Mobile Wireless Access Network

With the soaring demand to provide global mobility for wide range of services, a growing trend for wireless access networks is to support multiple radio technologies that can be achieved efficiently by using TCP/IP protocols in the access network. In the thesis, we consider a mobile wireless access network where DiffServ is deployed as the QoS solution and Mobile IP is employed as the handover protocol. We first conducted a study on the impact of handover on DiffServ flows. Then we introduced a transient service level for handover flows and propose our QoS scheme and admission control algorithms for handover flows, which protect local flows from losing bandwidth to handover flows by separating the two flows into different service classes. We also proposed a service upgrade algorithm to upgrade the service level of handover flows based on the dynamic information of bandwidth utilization and different service upgrade priorities. To guarantee the proper provisioning for each service class, we proposed a dynamic bandwidth-provisioning algorithm that allows dynamic adjustment of bandwidth allocations to different service classes by adjusting their respective weights configured at the scheduler. We evaluated the feasibility of our QoS scheme and algorithm by simulating different handover situations and results show that the proposed scheme is viable under variety of provisioning scenarios.