|
For Full-Text PDF, please login, if you are a member of IEICE,
or go to Pay Per View on menu list, if you are a nonmember of IEICE.
|
TCP Congestion Control with ACK-Pacing for Vertical Handover
Yosuke MATSUSHITA Takahiro MATSUDA Miki YAMAMOTO
Publication
IEICE TRANSACTIONS on Communications
Vol.E90-B
No.4
pp.885-893 Publication Date: 2007/04/01 Online ISSN: 1745-1345
DOI: 10.1093/ietcom/e90-b.4.885 Print ISSN: 0916-8516 Type of Manuscript: PAPER Category: Network Keyword: vertical handover, TCP, congestion control, ACK-pacing,
Full Text: PDF(1.4MB)>>
Summary:
In this paper, we discuss TCP performance in a wireless overlay network where wireless LANs and cellular networks are integrated. In the overlay network, vertical handover, where a mobile node changes its access link during a session, is one of the most important technologies. When a vertical handover occurs, throughput performance of a TCP flow is degraded due to not only packet losses during the handover, but drastic change of its bandwidth-delay product. In this paper, we propose an ACK-pacing mechanism for TCP congestion control to improve the performance degradation. The proposed system is receiver-driven, so no modification is required to the mechanism of TCP sender. In the proposed system, a TCP receiver adjusts a transmission rate of ACKs according to the relationship between bandwidth-delay products before and after a handover. Since the ACK-clocking mechanism of TCP adjusts the transmission rate of TCP segments, the TCP receiver can seamlessly adjust its congestion window size to the new bandwidth-delay product. Computer simulation results show that the proposed system can improve the TCP performance during the vertical handover.
|
|
|