Radio resource management and operator sharing in 3G WCDMA multimedia wireless networks

Abstract

Currently, 3G and beyond cellular wireless networks supporting heterogeneous traffic with variable quality of service (QoS) requirements is already a reality. Efficient bandwidth utilization is the most important requirement for a radio resource management (RRM) technique along with satisfying the necessary QoS constraints in a wireless environment with limited bandwidth. For 3G mobile networks, such as the Universal Mobile Telecommunications System (UMTS) with Wideband Code Division Multiple Access (WCDMA) as its radio access interface, various resource management algorithms such as call admission control (CAC) and packet scheduling need to be improved to properly handle multiple services and maximize resource utilization. This dissertation focuses on QoS oriented radio resource allocations and performance analysis for UMTS WCDMA cellular networks supporting multimedia services. In order to differentiate among the services by achieving the service specific QoS and optimally managing the scarce radio resources, prioritized CAC schemes are proposed and analyzed. Analytical and simulation models are developed for the proposed CAC schemes and the results are found to be in good agreements. Performance analysis indicates that in order to achieve the best trade off for overall system utilization while respecting every service QoS requirements, it is vital to provide a service protection for both lowest rate real time (RT) and non-real time (NRT) services from affecting each other. This goal can be achieved by controlling their required QoS while utilizing all the available resources in an adaptive and fair way. These conflicting requirements have been achieved using the proposed dynamic prioritization CAC that allows dynamic shifting of capacity between different traffic classes. This scheme results in fully utilized resources and provides additional flexibility and fairness in the management of available radio resources. The issue of radio resource sharing, as a new important future trend for 3G RRM, is also considered. Sharing of 3G WCDMA becomes an important issue for 3G mobile operators, especially as network evolves towards 4G. The driving factors for this sharing include economic factor as well as the quick rolling out of the network infrastructure. In this regard, different exiting proposed network sharing options are discussed. The radio access network sharing (RAN), as one of these options, is considered. Then, efficient radio resource allocations and scheduling strategies have been proposed in order to enhance the RRM to cope with these new changes. These schemes are to ensure the minimum resource requirements for each operator and the highest system utilization on the uplink shared resources of a 3G WCDMA network, supporting multiple operators. Toward this ends, a Multi-operator code division generalized processor sharing (M-CDGPS) scheme, with static and adaptive rate, is proposed and analyzed. Simulation results show that the adaptive rate M-CDGPS scheme improves both system utilization and average delays and allows for a flexible trade-off between the GPS fairness and efficiency in resource utilization.