Context-Aware Streaming Video System for Vertical Handover over Wireless Overlay Network

Streaming video would become a popular form of transferring video over next-generation wireless overlay networks. As transport protocol for streaming video, TCP- friendly rate control (TFRC) is generally used. Using both TCP congestion response function and current network conditions, TFRC adjusts transmission rate so as to achieve maximum TCP-friendly throughput. However, TFRC is less responsive to changes in handover between wireless overlay networks, since it was designed for applications that would prefer to maintain a slowly-changing transmission rate. Also, the transferred streaming video could be degraded owing to the service interruption time occurred during vertical handover (VHO) process. In this paper, a new cross-layer TFRC streaming video system is demonstrated for VHO over wireless overlay network. The proposed system consists of a VHO based TFRC server and a TFRC client with VHO decision function. The proposed TFRC server uses explicit VHO messages for faster rate adaptation to a new target network. Also, the proposed TFRC client decides on switching time between different overlay networks by using handoff metrics obtained from multi-layers. The simulation results show that the proposed streaming video system provides better QoS and throughput supports than the conventional TFRC scheme during VHO .