Video quality guarantee for mobile users across WLAN/3G networks

The network-centric CAC schemes try to do resource reservation into networks for mobile connections, observing network status only. This approach can be appropriate for non-real time traffic, but for real-time applications, hasn´t showed good results. In this paper, we introduce the PI-CAC, a user-centric L3 CAC scheme, based on user quality of experience for integrating WLAN and 3G networks, with the objective of guarantee the best video quality for users of these networks. Our CAC scheme works at network layer, considering that mobiles are multimode terminals, with L1 and L2 connections always actives. So, the mobile connection request is accepted in networks through brokers, located in network coverage area as multimode clients. These brokers are controlled by networks and use QoS informations received of the networks, at the same time that calculate the QoE of video requested by user. The performance of our solution was evaluated using a testbed implementation into a real scenario and the results were better when compared to solutions based on traditional approaches.