Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Improving TCP Performance in Wireless Multi-hop Networks: Design of Efficient Forwarding and Packet Processing Techniques
Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science.ORCID iD: 0000-0002-4366-6625
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Due to the high availability of cheap hardware, wireless multi-hop networks and in particular Wireless Mesh Networks (WMNs) are becoming popular in more and more contexts. For instance, IEEE 802.11 based WMNs have already started to be deployed as means to provide Internet access to rural areas in the developing world. To lower the cost and increase the coverage in such deployments, the wired network is extended with a wireless backbone of fixed mesh routers. With advances in technology and reduction in price comes also the possibility for more powerful wireless nodes, having multiple radios that allow transmitting on different channels in parallel.

To be a successful platform for providing general Internet access, wireless multi-hop networks must provide support for common Internet applications. As most of the applications in the Internet today use the Transmission Control Protocol (TCP), TCP performance is crucial. Unfortunately, the design of TCP’s congestion control that made it successful in today’s Internet makes it perform less than optimal in wireless multi-hop networks. This is due to, among others, TCP’s inability to distinguish wireless losses from congestion losses. The current trend for operating system designers is also to focus TCP development on high-speed fixed networks, rather than on wireless multi-hop networks. To enable wireless multi hop networks as a successful platform there is therefore a need to provide good performance using TCP variants commonly deployed in the Internet.

In this thesis, we develop novel proposals for the network layer in wireless multi-hop networks to support TCP traffic more efficiently. As an initial study, we experimentally evaluate different TCP variants, with and without mobile nodes, in a MANET context.

Our results show that TCP Vegas, which does not provoke packet loss to determine available bandwidth, reduces the stress on the network while still providing the same or slightly increased performance, compared to TCP Newreno. We further propose and evaluate packet aggregation combined with aggregation aware multi-path forwarding to better utilize the available bandwidth.

IP layer packet aggregation, where small packets are combined to larger ones before sent to the link layer, has been shown to improve the performance in wireless multi-hop networks for UDP and small packet transfers. Only few studies have been made on the impact of packet aggregation on TCP traffic, despite the fact that TCP traffic constitutes the majority of the Internet traffic. We propose a novel aggregation algorithm that is specifically addressing TCP relevant issues like packet reordering, fairness and TCP timeouts. In a typical WMN scenario, the aggregation algorithm increases TCP performance by up to 70 % and decreases round trip time (RTT) by up to 40 %.

A detailed evaluation of packet aggregation in a multi radio setting has shown that a naive combination of multi path routing and packet aggregation can cause valuable aggregation opportunities to be lost. Therefore, we propose a novel combined packet aggregation and aggregation aware forwarding strategy that can reduce delay, packet loss and increase TCP performance by around 30 %.

Place, publisher, year, edition, pages
Karlstad: Karlstad University , 2011. , p. 26
Series
Karlstad University Studies, ISSN 1403-8099 ; 2011:5
Keywords [en]
TCP, transport protocols, packet aggregation, multi path routing, wireless mesh networks
National Category
Computer Sciences
Research subject
Computer Science
Identifiers
URN: urn:nbn:se:kau:diva-6820ISBN: 978-91-7063-337-9 (print)OAI: oai:DiVA.org:kau-6820DiVA, id: diva2:392473
Presentation
2011-03-16, Sjöströmsalen, 1B 309, Karlstads universitet, Karlstad, 10:15 (Swedish)
Supervisors
Available from: 2011-02-22 Created: 2011-01-27 Last updated: 2018-07-23Bibliographically approved
List of papers
1. TCP Performance in Mobile Ad Hoc Networks Connected to the Internet
Open this publication in new window or tab >>TCP Performance in Mobile Ad Hoc Networks Connected to the Internet
2007 (English)In: REVISTA CIENTÍFICA PERIÓDICA - TELECOMUNICAÇÕES, Vol. 10, no 1, p. 22-29Article in journal (Refereed) Published
Identifiers
urn:nbn:se:kau:diva-7060 (URN)
Available from: 2011-02-18 Created: 2011-02-17 Last updated: 2013-06-19Bibliographically approved
2. Impact of Packet Aggregation on TCP performance in Wireless Mesh Networks
Open this publication in new window or tab >>Impact of Packet Aggregation on TCP performance in Wireless Mesh Networks
2009 (English)In: Proceedings of the First IEEE WoWMoM Workshop on Hot Topics in Mesh Networking (HotMESH'09), IEEE , 2009, p. 1-7Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
IEEE, 2009
National Category
Computer Sciences
Identifiers
urn:nbn:se:kau:diva-7067 (URN)10.1109/WOWMOM.2009.5282435 (DOI)978-1-4244-4440-3 (ISBN)
Available from: 2011-02-18 Created: 2011-02-18 Last updated: 2018-07-23Bibliographically approved
3. Evaluation of Packet Aggregation with TCP Traffic in Wireless Mesh Networks
Open this publication in new window or tab >>Evaluation of Packet Aggregation with TCP Traffic in Wireless Mesh Networks
2010 (English)Manuscript (preprint) (Other (popular science, discussion, etc.))
National Category
Computer Sciences
Identifiers
urn:nbn:se:kau:diva-7068 (URN)
Available from: 2011-02-18 Created: 2011-02-18 Last updated: 2018-07-23Bibliographically approved
4. An Aggregation Aware Multi-path Forwarding Paradigm for Wireless Mesh Networks
Open this publication in new window or tab >>An Aggregation Aware Multi-path Forwarding Paradigm for Wireless Mesh Networks
2011 (English)In: Proceedings of 10th International IFIP-TC6 conference on Networking, Springer Berlin/Heidelberg, 2011Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2011
National Category
Computer Sciences
Identifiers
urn:nbn:se:kau:diva-7070 (URN)978-3-642-20797-6 (ISBN)
Conference
The 10th International IFIP-TC6 Networking Conference (Networking 2011), Valencia, Spain, May 2001
Available from: 2011-02-18 Created: 2011-02-18 Last updated: 2018-07-23Bibliographically approved

Open Access in DiVA

fulltext(442 kB)1219 downloads
File information
File name FULLTEXT01.pdfFile size 442 kBChecksum SHA-512
03845d7138caad8dfbb625cdbe17cd13dba94d35e51f65301539c437d92dbfb16416a6a548ce41ee903af1b9c76364f6d73c0b02d06db196373c6524b848aee7
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Karlsson, Jonas
By organisation
Department of Computer Science
Computer Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 1219 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 607 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf