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
Cost Effective Interference Management in Ultra-dense Hotspot Mobile Broadband Systems
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.
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Rapid mobile data traffic growth is becoming in a reality and several forecasts expect that it will be continued in upcoming years. It is expected that significant indoor investment will be made not only by traditional operators but also by facility owners for their own purposes. A key challenge to such local network providers is provisioning ever-increasing mobile traffic demand at the current level of production cost per bit. A popular deployment strategy so far is deploying WLAN networks. While denser indoor deployment is foreseen, the interference from inside of a network as well as other neighboring operators can be a limiting factor for higher capacity. Tighter interference management will certainly provide higher efficiency in network and spectrum usage. Nevertheless, costs to allow fast information sharing among access points are necessary for advanced interference coordination. Moreover, managing interference across networks owned by different operators raises not only infrastructure cost but also the network interrelatedness which operators are typically reluctant for business independency. When taking into account the cost and barriers for interference coordination, it is still not so obvious that coordination in wireless broadband systems will be advantageous to operators.

In this thesis, we address the operator benefit of downlink interference coordination in two aspects: 1) multi-cell coordination with no interference from neighboring operators, and 2) inter-operator coordination in shared spectrum. In order to deal with interference and cost tradeoff analysis, we explicitly develop a techno-economic analysis framework and reform a traditional cost model. Numerical results indicate that the economic benefit of the multi-cell coordination significantly depends on propagation conditions and average user demand level. A self-deployed WLAN network can be the cheapest deployment option in closed areas up to certain average demand level. Over the demand level or in open areas, advanced joint processing schemes in a cellular domain may be a viable solution. The drawback is that it requires extremely accurate channel state information at transmitters for practical usage. When inter-operator interferences is present, asymmetric cellular networks will be likely to appear due to business independency and selfishly compete to access spectrum with no or little network-level coordination. A network designed for more fairness with higher transmission power will have more benefit against the other counterpart. Although asymmetric competition lets operators unfairly utilize spectrum, sharing spectrum with reasonable geographical separation can outperform over static coordination, i.e., traditional spectrum split. Tight cooperation to maximize a common objective can further offer the performance benefit to both involved partners. However, the cooperation gain quickly diminishes as network separation and size increases because self-interference becomes more dominant.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. , viii, 55 p.
National Category
Telecommunications
Identifiers
URN: urn:nbn:se:kth:diva-104100OAI: oai:DiVA.org:kth-104100DiVA: diva2:563181
Presentation
2012-11-27, C1, Electrum 229, Isafjordsgatan 26, Kista, 15:00 (English)
Opponent
Supervisors
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
ICT - The Next GenerationWireless@kth
Note

QC 20121031

Available from: 2012-10-31 Created: 2012-10-29 Last updated: 2013-11-28Bibliographically approved
List of papers
1. High capacity indoor and hotspot wireless systems in shared spectrum: A techno-economic analysis
Open this publication in new window or tab >>High capacity indoor and hotspot wireless systems in shared spectrum: A techno-economic analysis
2013 (English)In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 51, no 12, 102-109 p.Article in journal (Refereed) Published
Abstract [en]

Predictions for wireless and mobile Internet access suggest an exponential traffic increase, particularly in in-building environments. Non-traditional actors such as facility owners have a growing interest in deploying and operating their own indoor networks to fulfill the capacity demand. Such local operators will need spectrum sharing with neighboring networks because they are not likely to have their own dedicated spectrum. Management of internetwork interference then becomes a key issue for high capacity provision. Tight operator-wise cooperation provides superior performance, but at the expense of high infrastructure cost and business-related impairments. Limited coordination, on the other hand, causes harmful interference between operators, which in turn will require even denser networks. In this article, we propose a techno-economic analysis framework for investigating and comparing indoor operator strategies. We refine a traditional network cost model by introducing new inter-operator cost factors. Then we present a numerical example to demonstrate how the proposed framework can help us to compare different operator strategies. Finally, we suggest areas for future research.

Keyword
Operator strategy, Techno-Economic analysis framework, Shared spectrum, Indoor and hotspot deployment
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-104175 (URN)10.1109/MCOM.2013.6685764 (DOI)000328984300013 ()2-s2.0-84891621985 (Scopus ID)
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
Wireless@kth
Note

QC 20140130. Updated from submitted to published.

Available from: 2012-10-29 Created: 2012-10-29 Last updated: 2017-12-07Bibliographically approved
2. Cost and Feasibility Analysis of Self-deployed Cellular Networks
Open this publication in new window or tab >>Cost and Feasibility Analysis of Self-deployed Cellular Networks
2011 (English)In: 2011 IEEE 22nd International Symposium On Personal Indoor And Mobile Radio Communications (PIMRC), New York: IEEE , 2011, 248-252 p.Conference paper, Published paper (Refereed)
Abstract [en]

A self-deployed network is considered to be one of cost-efficient deployment solutions by skipping an expensive network planning process. However, it may result in the serious degradation of capacity or the infeasibility of coverage constraint due to the rise of interference although radio adaptation techniques are employed. Therefore, deployment decision makers, e.g., operators, need to identify when and where the self-deployed network is feasible and economical compared with the planned network. For this, we estimate the average network throughput of the self-deployed network subject to a coverage constraint and compare it with the planned network. Three distinct regions of self-deployment are identified where different deployment strategies are required: infeasible, cost-effective, and uneconomical. We evaluate how the regions alter according to different channel environments and make suggestions for economical deployment.

Place, publisher, year, edition, pages
New York: IEEE, 2011
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-70459 (URN)10.1109/PIMRC.2011.6139959 (DOI)000300719700049 ()2-s2.0-84857609708 (Scopus ID)978-1-4577-1346-0 (ISBN)
Conference
22nd IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) Location: Toronto, Canada, Date: SEP 11-14, 2011
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
Wireless@kth
Note

QC 20120201

Available from: 2012-01-30 Created: 2012-01-30 Last updated: 2016-04-27Bibliographically approved
3. Is Multicell Interference Coordination Worthwhile in Indoor Wireless Broadband Systems?
Open this publication in new window or tab >>Is Multicell Interference Coordination Worthwhile in Indoor Wireless Broadband Systems?
2012 (English)In: 2012 IEEE Global Communications Conference (GLOBECOM), IEEE , 2012, 4255-4260 p.Conference paper, Published paper (Refereed)
Abstract [en]

The rapid growth in demand for mobile and nomadic wireless access forces the use of more and more base stations (BSs). In such dense networks, various techniques for multicell interference coordination have been investigated. However, whether or not the interference coordination provides cost benefit compared with a loosely coordinated system is not obvious because the tight coordination at PHY-layer is likely to need an expensive high-speed backbone infrastructure. In this paper, we assess the worthiness of the tight interference coordination, referred to as coordination gain, in various indoor environments. We compare a hypothetical interference-free system as an upper bound with a simple interference-limited system opportunistically avoiding interference. The range of possible coordination gain is examined for various wall losses, path loss exponents, building shapes, and deployment density. Results show that substantial gain can be achieved in dense deployment at open areas with low path loss exponent, e.g., lightly furnished offices partitioned with soft walls. Nevertheless, the coordination gain significantly drops in the presence of marginal wall loss regardless of the other environmental factors.

Place, publisher, year, edition, pages
IEEE, 2012
Series
IEEE Global Telecommunications Conference (Globecom), ISSN 1930-529X
Keyword
Coordinated system, Environmental factors, Interference co-ordination, Interference-limited systems, Multi-cell interferences, Path loss exponent, Tight coordination, Wireless broadband
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-104179 (URN)10.1109/GLOCOM.2012.6503786 (DOI)000322375104104 ()2-s2.0-84877644166 (Scopus ID)978-146730921-9 (ISBN)
Conference
2012 IEEE Global Communications Conference, GLOBECOM 2012; Anaheim, CA; United States; 3 December 2012 through 7 December 2012
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
ICT - The Next GenerationWireless@kth
Note

QC 20121029

Available from: 2012-10-29 Created: 2012-10-29 Last updated: 2014-04-16Bibliographically approved
4. Economic Hotspot Deployment Strategy: Denser Wi-Fior Coordinated Pico-cellular?
Open this publication in new window or tab >>Economic Hotspot Deployment Strategy: Denser Wi-Fior Coordinated Pico-cellular?
(English)Article in journal (Other academic) Submitted
Abstract [en]

Rapidly increasing traffic demand has forced indoor operators to deploy more and more Wi-Fi access points (APs). As AP density increases, inter-AP interference rises and may limit the capacity. Alternatively, cellular technologies using centralize dinterference coordination can provide the same capacity with the fewer number of APs at the price of more expensive equipment and installation cost. It is still not obvious at what demand level more sophisticated coordination pays off in terms of total system cost. To make this comparison, we assess the required AP density of three candidate systems for a given average demand: a Wi-Fi network, a conventional pico-cellular network with frequency planning, and an advanced system employing multi-cell joint processing. Numerical results show that dense Wi-Fi is the cheapest solution at a relatively low demand level. However, the AP density grows quickly at a critical demand level regardless of propagation conditions. Beyond this “Wi-Fi network limit”, the conventional pico-cellular network works and is cheaper than the joint processing in obstructed environments, e.g., furnished offices with walls. In line of sight condition such as stadiums, the joint processing becomes the most viable solution. The drawback is that extremely accurate channel state information at transmitters is needed.

Keyword
Wi-Fi densification, Interference coordination, Networked MIMO, Cost-capacity analysis, Network deploymen
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-104193 (URN)
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
Wireless@kth
Note

NV 20160427

Available from: 2012-10-30 Created: 2012-10-30 Last updated: 2016-04-27Bibliographically approved
5. Impact of asymmetric transmission power on operator competition in shared spectrum
Open this publication in new window or tab >>Impact of asymmetric transmission power on operator competition in shared spectrum
Show others...
2012 (English)In: Communication Technologies Workshop (Swe-CTW), 2012 Swedish, IEEE , 2012, 25-29 p.Conference paper, Published paper (Refereed)
Abstract [en]

To maintain affordable access for the rapidly increasing mobile traffic, base station deployment has to be tailored to hot-spot areas and primarily indoors where facility owners, e.g., shopping malls or hotels, mostly provide wireless service. Since such local access providers (LAPs) do not have access to exclusive spectrum, one proposed option is sharing spectrum with other nearby LAPs, e.g. unlicensed or secondary spectrum. Due to limited or no coordination between the LAPs, they selfishly access the spectrum, causing harmful interference to the neighboring networks. Especially by increasing transmission power, one operator may attempt to improve its own throughput at the expense of its neighbors. In this paper, we explore the impact of power asymmetry on competition between LAPs. We model the competition between two networks with different maximum power constraints as a network-wide power control game. By analyzing the pure Nash equilibria, we find that a lower power (LP) network becomes more aggressive to overcome the inter-network interference. Due to the aggressive behavior, sharing spectrum can out-perform fixed spectrum split even for the LP network, provided that the power asymmetry is below a certain limit. On the other hand, a higher power (HP) network is mainly affected by its own 'self-interference' so that it has little incentive to employ complicated inter-operator interference management schemes. In addition, we demonstrate that the power asymmetry limit strongly depends on the inter-network propagation conditions, e.g., inter-building distance or building penetration loss.

Place, publisher, year, edition, pages
IEEE, 2012
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-104194 (URN)10.1109/Swe-CTW.2012.6376283 (DOI)2-s2.0-84871901073 (Scopus ID)978-146734763-1 (ISBN)
Conference
2012 Swedish Communication Technologies Workshop, Swe-CTW 2012; Lund; 24 October 2012 through 26 October 2012
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
ICT - The Next GenerationWireless@kth
Note

QC 20121030

Available from: 2012-10-30 Created: 2012-10-30 Last updated: 2016-04-21Bibliographically approved
6. Operator competition with asymmetric strategies in shared spectrum
Open this publication in new window or tab >>Operator competition with asymmetric strategies in shared spectrum
2012 (English)In: 2012 IEEE Wireless Communications and Networking Conference, WCNC, IEEE Communications Society, 2012, 3183-3187 p.Conference paper, Published paper (Refereed)
Abstract [en]

As the regulation in wireless communications is moving toward a more flexible and efficient way of managing radio spectrum, it is envisaged that multiple small-sized cellular networks owned by different operators, e.g., facility owners or local operators, will operate in close vicinity on shared spectrum. In this environment, the networks may compete for their own utilities in a selfish manner with giving harmful internetwork interference to competitors. In practice, it is not so unusual that each operator has different fairness criteria or quality of service (QoS) strategies by employing distinct objective functions from competitors. Particularly, we in this paper study power control competition between two networks with the sum of rates (SR) and the minimum rate (MR) as their objective functions, respectively. By exploring Nash equilibria, we identify that the MR network benefits from the objective asymmetry thanks to the adaptability of its competitor, i.e., no constraint in the SR objective. On the other hand, the SR network takes disadvantage due to the fairness requirement reflected in the MR objective of its competitor. However, such asymmetry effects in competition becomes negligible with marginal network separation, e.g., indoor deployment in adjacent buildings. Additionally, we identify cooperation potential with the proper choice of a common objective function although the asymmetric objectives are difficult to be aligned.

Place, publisher, year, edition, pages
IEEE Communications Society, 2012
Series
IEEE Wireless Communications and Networking Conference. Proceedings, ISSN 1525-3511
Keyword
Adjacent buildings, Cellular network, Facility owners, Fairness criteria, Local operators, Nash equilibria, Objective functions, Radio spectra, Wireless communications, Quality of service, Telecommunication networks, Wireless telecommunication systems
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-101553 (URN)10.1109/WCNC.2012.6214355 (DOI)000324580703052 ()2-s2.0-84864349727 (Scopus ID)978-146730437-5 (ISBN)
Conference
IEEE Wireless Communications and Networking Conference, WCNC 2012; Paris; 1 April 2012 through 4 April 2012
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
ICT - The Next GenerationWireless@kth
Note

QC 20120905

Available from: 2012-09-05 Created: 2012-08-30 Last updated: 2014-04-16Bibliographically approved
7. Cooperation and Competition between Wireless Networks in Shared Spectrum
Open this publication in new window or tab >>Cooperation and Competition between Wireless Networks in Shared Spectrum
2011 (English)In: 2011 IEEE 22nd International Symposium On Personal Indoor And Mobile Radio Communications (PIMRC), New York: IEEE , 2011, 284-288 p.Conference paper, Published paper (Refereed)
Abstract [en]

As the regulation in wireless communications is moving toward a more flexible and efficient way of managing radio spectrum, it is envisaged that multiple small-sized cellular networks owned by different operators will operate in close vicinity on shared spectrum. This brings a new interference environment where a cell is interfered by not only base stations in own network but also those in other networks. These networks may compete for their own utilities in a selfish manner or cooperate in order to minimize the mutual interference. Since a cooperation between the networks requires a business-wise agreement or extra infrastructure cost, the operators have to identify how much they will benefit from the cooperation. In this paper, we compare the effects of competition and cooperation between the cellular networks. The competition and cooperation are modeled as a transmit power control in downlink. It is observed that the cooperation in an average sense gives better network utility. However, as the network size increases, the cooperation gain diminishes significantly. Furthermore, the marginal separation of network deployments, e.g., indoor deployments in adjacent buildings, can notably shrink the cooperation incentive.

Place, publisher, year, edition, pages
New York: IEEE, 2011
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-70458 (URN)10.1109/PIMRC.2011.6139967 (DOI)000300719700056 ()2-s2.0-84857516681 (Scopus ID)978-1-4577-1348-4 (ISBN)
Conference
22nd IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) Location: Toronto, Canada, Date: SEP 11-14, 2011
Projects
The Mobile Broadband Project Phase 3: “More for less” (MBB++)
Funder
Wireless@kth
Note

QC 20120201

Available from: 2012-01-30 Created: 2012-01-30 Last updated: 2016-04-26Bibliographically approved

Open Access in DiVA

fulltext(6202 kB)1315 downloads
File information
File name FULLTEXT01.pdfFile size 6202 kBChecksum SHA-512
067777f41e47ab31486a1efe714d354bc8ddd3f52b58684e88505062514b867ab8d91894554eed6fcda017fab99128081020b432c7c0950fdd99884b8a0960de
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Kang, Du Ho
By organisation
Communication Systems, CoSCenter for Wireless Systems, Wireless@kth
Telecommunications

Search outside of DiVA

GoogleGoogle Scholar
Total: 1315 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

urn-nbn

Altmetric score

urn-nbn
Total: 380 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