By Topic

Using Quick-Start to Improve TCP Performance with Vertical Hand-offs

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Pasi Sarolahti ; Nokia Research Center, P.O. Box 407, 00045 NOKIA GROUP, Finland. ; Jouni Korhonen ; Laila Daniel ; Markku Kojo

Vertical hand-offs between different wireless access technologies have become more relevant after the introduction of multi-access mobile terminals with wireless LAN (WLAN) and wireless WAN (WWAN) technologies. While the IP mobility mechanisms are rather well known, the performance of TCP still has problems when moving between WLAN and WWAN accesses. First, with a high-latency WWAN link technology such as GPRS it takes several seconds before the TCP congestion window has reached the path capacity. Second, when the notification of the first packet loss arrives at the TCP sender, several packets have already been lost due to the slow-start overshoot and the TCP sender needs to retransmit a large number of the packets from the last transmission window. Third, after a vertical hand-off the path characteristics might have changed dramatically in which case the TCP congestion control state is not valid any more. In this paper we investigate Quick-Start, a mechanism for avoiding the initial slow-start delay, in the context of wireless multi-access terminals. We also propose an enhancement to Quick-Start to alleviate the effects of slow-start overshoot and apply Quick-Start after a vertical hand-off to quickly learn the available capacity on the new end-to-end path. An explicit cross-layer hand-off notification is employed to trigger Quick-Start when the hand-off completes. We conduct simulations with different hand-off models, and our simulations yield promising results with Quick-Start

Published in:

Proceedings. 2006 31st IEEE Conference on Local Computer Networks

Date of Conference:

14-16 Nov. 2006