On optimal network selection in a dynamic multi-RAT environment

A significant challenge to enable multimedia service delivery in a dynamic multiple radio access technologies (multi-RAT) environment is the coordination of vertical handovers between different RATs. Cost function approach has been widely adopted to make vertical handover decision by ranking candidate networks. Although this mechanism can reflect accurately the change of network states and user requirements, it results in frequent, and often, unnecessary handovers which have detrimental impact on QoS, signaling load and system capacity. In this letter, we introduce a novel measurement-based network selection technique that provides a pragmatic way to acquire QoS information. In addition, it augments the handover decision of existing cost function approach, through handover initiation, to provide an optimal network selection outcome. OPNET simulations verify that the proposed technique can reduce unnecessary handovers considerably, improve overall QoS and system capacity.