Performance Enhancement of TFRC in Wireless Networks
نویسندگان
چکیده
The TCP-Friendly Rate Control (TFRC) is used as a streaming media transport protocol. Using the TCP congestion response function and current network conditions, TFRC adjusts its transmission rate to yield the maximum TCP-Friendly throughput when sharing capacity with TCP flows. Since TFRC was designed for wired networks, it does not achieve the maximum TCP-Friendly throughput in multihop ad hoc wireless networks. The reduced wireless spatial channel reuse due to hidden terminals in multihop wireless networks induces TFRC throughput reductions. Specifically, TFRC is unaware of MAC layer transmission delays due to collisions, retransmissions and MAC layer congestion. This paper illustrates that an unmodified TFRC’s sending rate overloads the multihop wireless MAC layer, leading to increased round-trip times, higher loss event rates, and lower throughput. We propose an enhancement to TFRC, called RE TFRC, that uses measurements of the current round-trip time and a model of wireless delay to restrict TFRC bitrates from overloading the MAC layer, while retaining desirable TCP-Friendly characteristics. RE TFRC requires minimal changes to TFRC and no changes to the MAC layer and evaluation of RE TFRC show substantial improvements over TFRC for some wireless scenarios. Keywords—TCP-Friendly, TFRC, IEEE 802.11, MAC, Ad Hoc, Multihop, Wireless
منابع مشابه
Performance Enhancement of TFRC in Wireless Ad Hoc Networks
The TCP-Friendly Rate Control (TFRC) is a rate-based transport protocol designed for streaming multimedia applications to provide smooth, low delay and TCP-Friendly packet transmission. However, as TFRC was designed for wired networks, it does not perform well in multihop ad hoc wireless networks. Specifically, MAC layer contention effects, such as retransmission and exponential backoff mislead...
متن کاملRate Control over Wired/Wireless Networks
TFRC is a TCP-Friendly Rate Control protocol based on TCP Reno's throughput equation. It is designed to provide optimal service for unicast multimedia flow operating in the wired Internet environment. However, in wireless networks, TFRC, same as TCP Reno, suffers significant performance degradation. In this paper, we propose to make use of a more advanced equation to enhance TFRC over wireless ...
متن کاملA New Congestion Control Approach on TFRC Over Wired and Wireless Networks
For advanced streaming applications over wired-wireless networks TCP-Friendly Rate Control (TFRC) has been widely adopted nowadays to give smooth sending rate and unceasing quality in streaming applications TFRC applies an equation-based rate control scheme. However, TFRC tends to fail in wireless environment if packet lost event was done by poor channel quality but network congestion. Therefor...
متن کاملPerformance of TFRC during vertical handovers events in heterogeneous networks
The TCP-friendly Rate Control (TFRC) is an adaptation scheme that provides TCP-friendly rate adaptation for Internet multimedia applications. While extensions have being proposed for wireless networks, TFRC was initially designed for wired networks. However, the behavior of TFRC in heterogeneous wireless networks, such the ones envisaged for the Beyond 3G and 4G systems, has not yet being exten...
متن کاملAn Enhanced All-in-one Tfrc Protocol for Streaming Video in Wireless Networks
Rate control is an important issue in video streaming applications for both wired and wireless networks. The widely accepted rate control method in wired networks, i.e. TCP friendly equation based rate control (TFRC) [1], is known to perform suboptimally in wireless networks. In previous work, we proposed MULTFRC as an end-to-end approach to fully utilize wireless bandwidth, modifying only appl...
متن کامل