Performance analysis of TFRC over wireless link with truncated link-level ARQ

In this paper, an analytical framework is proposed for evaluating the quality of service (QoS) of TCP-friendly rate control protocol (TFRC) in hybrid wireless/wired networks. For the wireless network, a link-level truncated automatic repeat request (ARQ) scheme is deployed to reduce the packet losses visible to the transport layer protocol. Two discrete time Markov chains (DTMC) are introduced to analyze the network performance and the QoS of the TFRC protocol, in terms of wireless link utilization, flow throughput, packet loss rate, and probability of end-to-end delay exceeding a prescribed threshold. Extensive simulations are performed to verify the accuracy of the analytical results. It is concluded that the analytical results are useful for optimizing the system parameters, such as the interface buffer size and the maximum number of retransmissions of the truncated ARQ scheme. With the optimal parameters, wireless link utilization can be maximized, and the QoS requirements of multimedia applications can be statistically guaranteed.