Extending QoS from Radio Access to an All-IP Core in 3G Networks: An Operator's Perspective

The convergence of wireless radio networks with all-IP networks has gained significant attention due to the ever increasing proliferation of IP technologies toward base stations as well as advances in air interfaces and wireless multimedia applications. Within standardization bodies, significant efforts are underway to address the support of QoS within the radio access network and Internet multimedia subsystem. For successful end-to-end application delivery, QoS and user profile unification are critical challenges, as is the intertwined policy enforcement between the IMS and the radio network. In this article we present a comprehensive analysis of QoS signaling over the integrated RAN and IMS domains. By using an imaginary service example, referred to as family media service, we analyze the specifics of end-to-end QoS invocation, control, and policy enforcement, including roaming scenarios. Based on laboratory measurements and simulations, we assess the call-setup delay, and recommend RAN and IMS signaling optimizations for delay reduction. We conclude the article by outlining open issues and proposing viable solutions.