Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Service Provisioning with Ad-Hoc Deployed High-Speed Access Points in Urban environments
KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.ORCID iD: 0000-0003-4986-6123
2005 (English)In: 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005, IEEE conference proceedings, 2005, Vol. 3, 2019-2023 p.Conference paper, Published paper (Refereed)
Abstract [en]

 Exploiting user-deployed networks as part of a public infrastructure has been proposed as a concept to radically lower the cost of provisioning access and services in urban environments. An important question is how dense a network with spotty coverage has to be in order to support interesting services. In this paper1, we introduce a framework for evaluating the user-perceived performance for two service types, a time-critical news subscription service (involving streaming) and a more delay tolerant entertainment service ("web browsing"). The user terminals contain a memory cache and an "agent" that opportunistically downloads and stores relevant pieces of information as users walk close to the access points. Results show that above a critical access point density, that is still significantly lower than the one required for continuous coverage, the services start performing very well with little or no outdated information. In most studied scenarios, we are communication limited meaning that memory capacity is not a problem, but energy is.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2005. Vol. 3, 2019-2023 p.
Keyword [en]
Cache memory, HIgh speed networks, Information retrieval systems, Telecommunication services
National Category
Telecommunications
Identifiers
URN: urn:nbn:se:kth:diva-7635DOI: 10.1109/PIMRC.2005.1651794Scopus ID: 2-s2.0-34047143732ISBN: 978-3-8007-2909-8 (print)OAI: oai:DiVA.org:kth-7635DiVA: diva2:12721
Conference
2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005
Note

QC 20100716

Available from: 2007-11-13 Created: 2007-11-13 Last updated: 2016-04-19Bibliographically approved
In thesis
1. Self-organization, cooperation and control distribution in wide and local area networks
Open this publication in new window or tab >>Self-organization, cooperation and control distribution in wide and local area networks
2007 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

To support the future requirements on wireless systems in an affordable manner it is commonly believed that multiple radio access technologies have to be combined. These technologies can be deployed by a single operator or, even, be managed by different competing operators. In order to cope with the increased complexity of such a multifaced wireless environment it has been argued that a transfer of Radio Resource Management (RRM) functionalities towards the network edges (access ports and, ultimately, user terminals) may be beneficial. In addition to detecting varying system conditions in a faster manner this would also allow a more responsive service adaptation. In this thesis we evaluate a set of self-organizing regimes, all with the purpose of supporting the distribution of control at the edge node.

Particular emphasis is put on the design of a mechanism for dynamically establishing cooperation between different network entities whether these are access ports or user terminals.

Terminal cooperation by means of multihopping is considered in the context of service provision in cellular access systems. Previously the opportunity cost associated with sharing own bandwidth, and energy loss have been seen as a major obstacle for relaying other users’ traffic. To mitigate the effects of this selfish behavior the concept of resource delegation is introduced and evaluated in combination with a rewarding scheme designed for compensating the energy losses induced by forwarding. The results show that our proposed schemes not only are capable of fostering significant cooperation among users, but also to create a simultaneous improvement in user utility, data rates as well as in operator revenues.

Opening up networks of user-deployed Access Points (APs) for service provision is considered a means to radically lower the cost of future wireless services. However, since these networks are deployed in an uncoordinated manner, only discontinuous coverage will be provided. The question of how dense these networks need to be, to deliver acceptable user perception, is investigated in this thesis for a set of archetypical services. The results show that already at moderate AP densities the investigated services can be provided with sufficient quality. Epidemic exchange of popular content and inter-AP cooperation are also shown to further decrease the required infrastructure density and improve the APs’ utilization respectively.

As last contribution, “Word-of-Mouth”, a distributed reputation-based scheme, is investigated in the context of access selection in multi-operator environments. By exchanging information concerning the Quality of Service (QoS) associated with the different networks, terminal agents can collectively reveal the capabilities of individual networks. For a vertical handover scenario we show that our proposed scheme can reward access providers capable of ensuring some degrees of QoS. By introducing a model for collusion, between low performing APs and terminal agents, we show that our proposed scheme is also robust to the dissemination of false information.

Place, publisher, year, edition, pages
Stockholm: KTH, 2007. x, 98 p.
Series
Trita-ICT-COS, ISSN 1653-6347 ; 0702
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-4533 (URN)
Presentation
2007-11-23, Sal N2, KTH-Electrum 3, Isafjordsgatan 28, Kista, Stockholm, 13:00
Opponent
Supervisors
Note
QC 20101112Available from: 2007-11-13 Created: 2007-11-13 Last updated: 2010-11-12Bibliographically approved
2. Context-based Resource Management and Architectures for Future Wide and Local Area Wireless Networks
Open this publication in new window or tab >>Context-based Resource Management and Architectures for Future Wide and Local Area Wireless Networks
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In the last few years we have been witnessing the beginning of a revolution in the world of wireless communication. The recent launch of advanced smartphones in the mobile market has been welcomed by mobile operators as an opportunity to finally fulfill the promises of 3G and increase the uptake of mobile services. Driven by unprecedented user experience and flat rate pricing, the success of novel mobile platforms for accessing multimedia content and applications has gone far beyond the most optimistic of expectations. Data-hungry services are currently creating significant capacity limitations in many networks, and projections on future content consumption anticipate that with the next generation of mobile devices the stress on cellular infrastructures will increase. Rolling-out additional capacity is not the most profitable of solutions given the current cost structure of mobile infrastructures. Instead, a significant cost reduction can be achieved by revolutionizing the current content provision paradigm. Accordingly, this thesis proposes solutions for making future services and infrastructures more affordable. From an operator perspective, terminal-to-terminal information forwarding has the potential to increase both coverage and capacity, however it introduces opportunity costs and energy losses at the user side. Resource delegation, together with an energy reimbursement scheme, is presented in this thesis to induce user cooperation. The results show that this approach is successful in fostering significant cooperation among users and can create a simultaneous improvement in user utility, data rates and operator revenues. Opening up for public access privately deployed WLANs might radically lower the cost of wireless services. However, since these networks are deployed in an uncoordinated manner, only discontinuous coverage can be provided. To hide the sparsity of the infrastructure to the end-user perception we propose the adoption of opportunistic schemes for content pre-fetching. Results show that already with moderate AP densities a set of archetypical services, including web-browsing, can be provided with sufficient user perceived quality. Epidemic exchange of popular content, and inter-AP cooperation are also shown to further decrease the required AP density. Moreover, to support informed access selection decisions when performing vertical handovers to WLANs, we propose “Word-of-Mouth”, a reputation-based scheme for revealing the QoS of different networks. By epidemically exchanging grades on their experienced service quality, we show that terminal agents can collectively improve their decision making, avoiding selecting networks not meeting the required QoS. Context-based content delivery is presented in this thesis as means to improve the utilization of wireless resources in cellular systems. Since networks are typically dimensioned for peak hour traffic, the BSs are underutilized for significant portions of the day. By adopting context-based architectures, capable of opportunistically utilizing the instantaneous excess of resources for content pre-fetching, we show that a significant amount of additional traffic can be served in already existing networks. The gains introduced by this content provision paradigm over the current “on-demand” solutions are further expressed in terms of lower requirements on BS density, more users in the system and larger files served while reaching the same level of user experience.

Place, publisher, year, edition, pages
Stockholm: KTH, 2010. xi, 156 p.
Series
Trita-ICT-COS, ISSN 1653-6347
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-12216 (URN)
Public defence
2010-04-16, C1, Electrum 1, Kungliga Tekniska Högskolan, Isafjordsgatan 26, Kista, 14:00 (English)
Opponent
Supervisors
Note
QC20100716Available from: 2010-04-08 Created: 2010-03-26 Last updated: 2010-07-16Bibliographically approved
3. Access selection in multi-system architectures: cooperative and competitive contexts
Open this publication in new window or tab >>Access selection in multi-system architectures: cooperative and competitive contexts
2007 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Future wireless networks will be composed of multiple radio access technologies (RATs). To benefit from these, users must utilize the appropriate RAT, and access points (APs). In this thesis we evaluate the efficiency of selection criteria that, in addition to path-loss and system bandwidth, also consider load. The problem is studied for closed as well as open systems. In the former both terminals and infrastructure are controlled by a single actor (e.g., mobile operator), while the latter refers to situations where terminals, selfishly, decide which AP it wants to use (as in a common market-place). We divide the overall problem into the prioritization between available RATs and, within a RAT, between the APs. The results from our studies suggest that data users, in general, should be served by the RAT offering highest peak data rate.

As this can be estimated by terminals, the benefits from centralized RAT selection is limited. Within a subsystem, however, load-sensitive AP selection criteria can increase data-rates. Highest gains are obtained when the subsystem is noise-limited, deployment unplanned, and the relative difference in number of users per AP significant. Under these circumstances the maximum supported load can be increased by an order of magnitude. However, also decentralized AP selection, where greedy autonomous terminal-based agents are in charge of the selection, were shown to give these gains as long they accounted for load. We also developed a game-theoretic framework, where users competed for wireless resources by bidding in a proportionally fair divisible auction. The framework was applied to a scenario where revenue-seeking APs competed for traffic by selecting an appropriate price. Compared to when APs cooperated, modelled by the Nash bargaining solution, our results suggest that a competitive access market, where infrastructure is shared implicitly, generally, offers users better service at a lower cost. Although AP revenues reduce, this reduction is, relatively, small and were shown to decrease with the concavity of demand. Lastly we studied whether data services could be offered in a discontinuous high-capacity network by letting a terminal-based agent pre-fetch information that its user potentially may request at some future time-instant. This decouples the period where the information is transferred, from the time-instant when it is consumed. Our results show that above some critical AP density, considerably lower than that required for continuous coverage, services start to perform well.

Place, publisher, year, edition, pages
Stockholm: KTH, 2007. xv, 180 p.
Series
Trita-ICT-COS, ISSN 1653-6347 ; 0701
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-4286 (URN)
Presentation
2007-03-09, Sal NA2, KTH-Electrum, Isafjordsgatan 28 b v, Kista, 14:00
Opponent
Supervisors
Note
QC 20101109Available from: 2007-02-27 Created: 2007-02-27 Last updated: 2010-11-09Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Zander, Jens

Search in DiVA

By author/editor
Hultell, JohanLungaro, PietroZander, Jens
By organisation
Communication Systems, CoSCenter for Wireless Systems, Wireless@kth
Telecommunications

Search outside of DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 115 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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