Fast link adaptation for TFRC after a handover

Abstract

Abstract-TCP-Friendly Rate Control(TFRC) is an equationbased congestion control mechanism that competes fairly with TCP but has a much lower throughput variation, which makes it a better choice for streaming over the Internet. It is known that in a mobile network environment, after a handover TFRC can overshoot or underutilize the new link if the conditions there differ from those of the old link. There are different factors that affect the TFRC performance during a handover. In this paper we focus on the impact of the change in the round trip time, an aspect that is largely overlooked in the literature compared with bandwidth disparity. We find that even if the same bandwidth is assured on the new link, changes in the link latency will still cause TFRC performance degradation after the handover. A fast link adaptation mechanism is thus proposed to address the problem. Simulations show that this mechanism helps TFRC to adjust quickly to the new link without consecutive packet loss or longtime bandwidth underutilization.

Freeze Dead Line Algorithm for Vertical Handoff in Heterogeneous Wireless Networks

“…We also measure the Congestion Control Window (CWND) to check the bandwidth adaptation after the hand-off. Parameters are drawn from related research [12,13]. Figure 10 shows the throughput in the downward hand-off environment using FDL, TCPReno and Fast-freeze.…”

Improving TFRC Performance against Bandwidth Change during Handovers

“…(In this paper we assume RTT is not changed during the handover. Handover with changed RTT has been studied in [8]). …”