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Hossain, M. I., Azari, A. & Zander, J. (2020). Collision Multiplicity Detection: Challenges, Solutions, and Impacts on Cellular Random Access. In: : . Paper presented at IEEE VTC-Spring. IEEE
Open this publication in new window or tab >>Collision Multiplicity Detection: Challenges, Solutions, and Impacts on Cellular Random Access
2020 (English)Conference paper, Published paper (Other academic)
Abstract [en]

In cellular and cellular-IoT systems, random access has the utmost importance as it is the gatekeeper that assures conflict-free access to radio resources. The main drawback of the legacy protocols lies at the collision resolution procedure as the base station (BS) is blind to the collision multiplicity and collided devices rely on the BSs for contention resolution. While contention resolution over the random access channel (RACH) is mature in the literature, most studies are following optimistic assumptions in which the full collision impact at the receiver is neglected, and a simplified model of partially overlapping packets is considered. This work is devoted to the investigation of a more realistic model of collision in cellular networks with the aim to investigate challenges and potential solutions in preamble detection in collision scenarios. The simulation results show that besides previously well-known challenges in dealing with collisions, the occurrence of collisions significantly increases the probability of false preamble detection.

Place, publisher, year, edition, pages
IEEE, 2020
National Category
Communication Systems
Research subject
Information and Communication Technology
Identifiers
urn:nbn:se:kth:diva-256518 (URN)
Conference
IEEE VTC-Spring
Note

Submitted. QC 20190903

Available from: 2019-08-27 Created: 2019-08-27 Last updated: 2019-09-03Bibliographically approved
Zander, J., Beckman, C. & Nilsson, M. (2019). Remissvar: "Betänkande av Utredningen om radiospektrumanvändningi framtiden – Frekvenser i samhällets tjänst" (SOU 2018:92): Diarie nummer N2019/00192/D. Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Remissvar: "Betänkande av Utredningen om radiospektrumanvändningi framtiden – Frekvenser i samhällets tjänst" (SOU 2018:92): Diarie nummer N2019/00192/D
2019 (Swedish)Other (Other (popular science, discussion, etc.))
Abstract [sv]

Betänkandet slår fast att frekvensspektrum är en viktig naturresurs som ur samhällets synpunkt måste användas så effektivt som möjligt. När olika användningsmöjligheter står mot varandra blir det svårt att avgöra vilken användning som ger störst samhällsnytta. Detta eftersom teknologi och innehåll för många tjänster är oklar eller tom okänd i det tidsperspektiv som anges. En fortsättning av pågående evolution är dock säkert, gäller också för metodiken runt spektrumallokering. Det är viktigt att spektrumallokering hantereras av en myndighet som i varje tidsskede har kompetens och inflytande för att utföra uppgiften på samma sätt som PTS gör idag.

 

KTH instämmer med konstaterandet att utvecklingen inom radio och kommunikation för tidsperioden 2027-2047 är omöjlig att förutse. Med detta följer också att metodiken för tilldelning av spektrum också kommer att behöva förändras över tid. Vi kommer att se nya tekniker för adaptivt val av frekvenser och effektiv delning av spektrum. Nya satellitbaserade system är under införande vilket förändrar distribution av ägande och tjänster i en global riktning.

 

Betänkandet är drivet av antagande om att efterfrågan på spektrum kommer att öka och därmed kommer bristen att öka dramatiskt. Huvudlösningen som förs fram är nya avgifter för att spegla nyttan. Vi inser att nya avgifter kan lösa en del av problemet men ser också att spektrumtilldelning är ett hantverk där många hänsyn måste tas. Helt olika motiv för användning måste vägas mot varandra. I det läget räcker inte en enda optimeringsmetod till, dvs nya avgifter. Vi ser ett stort behov av en myndighet som har nödvändig kompetens för att ta in alla dessa behov och göra de avvägningar som krävs.

 

Ömmande behov av säkerhet och trygghet i samhället, försvar, vetenskap, är näst intill omöjliga att hantera via en prissättning. De operatörer som idag har stor omsättning inom mobilt Internet har i regel betalt stora summor via auktion och betalar löpande operatörsavgifter i relation till omsättning (PTSFS 2018:06). Att mer eller mindre överföra denna princip på statliga organisationer och på så sätt rotera pengar runt mellan dem känns inte meningsfullt, däremot skall givetvis väl underbyggda hänsyn tas vid varje allokering.

Place, publisher, year, pages
Stockholm: KTH Royal Institute of Technology, 2019. p. 2
National Category
Telecommunications
Research subject
Telecommunication
Identifiers
urn:nbn:se:kth:diva-257894 (URN)
Note

QC 20190923

Available from: 2019-09-08 Created: 2019-09-08 Last updated: 2019-09-23Bibliographically approved
Zander, J. (2017). Beyond the Ultra-Dense Barrier: Paradigm Shifts on the Road beyond 1000x Wireless Capacity. IEEE wireless communications, 24(3), 96-102
Open this publication in new window or tab >>Beyond the Ultra-Dense Barrier: Paradigm Shifts on the Road beyond 1000x Wireless Capacity
2017 (English)In: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 24, no 3, p. 96-102Article in journal (Refereed) Published
Abstract [en]

It has become increasingly clear that the current design paradigm for mobile broadband systems is not a scalable and economically feasible way to solve the expected future "capacity crunch," in particular in indoor locations with large user densities. "Moore's law," for example, state-of-the art signal processing and advanced antenna techniques now being researched, as well as more millimeter wave spectrum, indeed provide more capacity, but are not the answer to the three to four orders of magnitude more capacity at today's cost, that is needed. We argue that solving the engineering problem of providing high data rates alone is not sufficient. Instead, we need to solve the techno-economic problem to find both business models and scalable technical solutions that provide extreme area capacity for a given cost and energy consumption. In this article we will show that achieving very high capacities is indeed feasible in indoor environments. However, to become economically viable, approaches with radically different fundamental cost factors compared to those used in today's cellular systems are needed. To reach very high capacity we must venture beyond the ultra-dense barrier, that is, networks where the number of access points in an area is (considerably) larger than the active number of mobile terminals. In such networks area capacities of more than 1 Gb/s/m2 are perfectly feasible. The problem set encountered in such UDN is very different from conventional cellular systems and their solution requires conceptually new tools. We will address some of the fundamental aspects and performance limits, modeling of propagation, deployment and user traffic, and discuss the techno-economics of various network architectures. Finally we will summarize some of the most significant unsolved research questions in the field.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-243535 (URN)10.1109/MWC.2017.1500377WC (DOI)000404379800020 ()2-s2.0-85009913156 (Scopus ID)
Note

QC 20190208

Available from: 2019-02-08 Created: 2019-02-08 Last updated: 2019-02-08Bibliographically approved
Hossain, M. I., Azari, A., Markendahl, J. & Zander, J. (2017). Enhanced Random Access:: Initial Access Load Balance in HighlyDense LTE-A Networks for Multiservice (H2H-MTC) Traffic. In: 2017 IEEE International Conference on Communications: . Paper presented at 2017 IEEE International Conference on Communications, ICC 2017; Paris; France; 21 May 2017 through 25 May 2017 (pp. 1-7). IEEE, Article ID 7996622.
Open this publication in new window or tab >>Enhanced Random Access:: Initial Access Load Balance in HighlyDense LTE-A Networks for Multiservice (H2H-MTC) Traffic
2017 (English)In: 2017 IEEE International Conference on Communications, IEEE, 2017, p. 1-7, article id 7996622Conference paper, Published paper (Refereed)
Abstract [en]

The Random Access (RA) procedure in existing cellular networks is not capable of functioning properly during high access load conditions. For this purpose, overload control mechanisms are needed. Most proposed mechanisms in the literature offer a tradeoff between access rate and experienced delays. However, when the maximal tolerated delay and the energy spent on retransmissions are tightly bounded, the very high access rate, targeted for 5G systems, cannot be achieved. For these situations, we propose the Delay Estimation based RA (DERA)-scheme that has the potential to meet very stringent reliability requirements, even in high access load conditions. The present work shows that this goal can be achieved only at the cost of limited additional complexity. Furthermore, we also study the optimal switchover point at which the proposed scheme moves from low-load to the high-load phase. The derived tool can also be used along with other proposed RA overload control schemes, e.g.when to invoke access class barring. The performance evaluation results show that the novel DERA scheme can significantly improve the control channels’ resource utilization along with the success rate in dense deployment scenarios.

Place, publisher, year, edition, pages
IEEE, 2017
Keywords
Random access, PRACH, 5G, Machine to machine communications, Propagation delay, contention.
National Category
Communication Systems
Research subject
Information and Communication Technology
Identifiers
urn:nbn:se:kth:diva-214960 (URN)10.1109/ICC.2017.7996622 (DOI)000424872101141 ()2-s2.0-85028360554 (Scopus ID)978-1-4673-9000-2 (ISBN)
Conference
2017 IEEE International Conference on Communications, ICC 2017; Paris; France; 21 May 2017 through 25 May 2017
Projects
H2020 project METIS-II
Funder
Wireless@kthEU, Horizon 2020, H2020-ICT-2014-2
Note

QC 20171002

Available from: 2017-09-26 Created: 2017-09-26 Last updated: 2019-08-27Bibliographically approved
Tombaz, S., Sung, K. W., Han, S. W. & Zander, J. (2016). An economic viability analysis on energy-saving solutions for wireless access networks. Computer Communications, 75, 50-61
Open this publication in new window or tab >>An economic viability analysis on energy-saving solutions for wireless access networks
2016 (English)In: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 75, p. 50-61Article in journal (Refereed) Published
Abstract [en]

As the energy bill for mobile operators rises with the continuing traffic growth, energy efficiency problems attract an increasing attention in the telecommunication industry. However, the investment for the implementation of any energy-saving solution could be so costly that it may not achieve the total cost reduction. Therefore, the economic viability of the proposed solutions is of substantial importance for the operators in the process of investment decisions. In this paper, we present a methodology for assessing the economic viability of energy-saving solutions. We conduct two case studies using the proposed methodology, and analyze the cost-benefit tradeoff for: (i) hardware upgrade enabling dynamic sleep mode operation at the base stations (BSs), and (ii) energy efficient network deployment minimizing the network energy consumption. Simulation results show that the hardware upgrade can save up to 60% of energy consumption particularly when the high data rate requirement forces low network resource utilization. Consequently, the solution is shown to be increasingly cost effective as the unit energy cost increases. Network deployment optimized for energy efficiency is shown to bring about further energy savings, but it demands denser deployment of BSs. Thus, it is not deemed as economically viable considering today's cost values.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Energy efficiency, Economic viability, Network planning, Cell DTX, Total cost of investment
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-184553 (URN)10.1016/j.comcom.2015.10.005 (DOI)000371843300004 ()2-s2.0-84959062279 (Scopus ID)
Note

QC 20160406

Available from: 2016-04-06 Created: 2016-04-01 Last updated: 2017-11-30Bibliographically approved
Han, S.-W. -., Kim, H., Han, Y., Cioffi, J. M., Leung, V. C. & Zander, J. (2016). Cooperative multiple access in cognitive radios to enhance QoS for cell edge primary users: asynchronous algorithm and convergence. Telecommunications Systems, 61(4), 631-643
Open this publication in new window or tab >>Cooperative multiple access in cognitive radios to enhance QoS for cell edge primary users: asynchronous algorithm and convergence
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2016 (English)In: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 61, no 4, p. 631-643Article in journal (Refereed) Published
Abstract [en]

Cognitive radio (CR) systems have been proposed for efficient usage of spare spectrum licensed to primary systems. This leads to the issue of providing as much spectrum to CR users as possible while not degrading the quality of service (QoS) of primary users of the spectrum. This paper proposes a novel cooperation scheme between primary and CR users to guarantee QoS of primary users up to the cell edge while making the licensed spectrum available for opportunistic access by the CR users. We suggest that the primary users at the cell edge, who have poor QoS, should allow secondary users to access their spectrum, while at the same time, the secondary users would help to enhance the primary users QoS using superposition coding on the primary users transmissions. Thus the proposed method can provide a so called “win-win strategy” by benefiting both primary and CR users. The proposed cooperative access scheme in cognitive radios solves efficiently the sum-rate maximization problem on cognitive Gaussian Multiple Access Channels (GMACs) for power allocation of primary systems that cooperates with CR systems in a distributed fashion. We solved the problem using iterative Jacobian method in a distributed manner. A totally asynchronous distributed power allocation for sum-rate maximization on cognitive GMACs is suggested. Numerical results show that the QoS of primary users at the cell edge is improved by the proposed cooperative access scheme.

Place, publisher, year, edition, pages
Springer-Verlag New York, 2016
Keywords
Cell edge primary users, Cognitive radio, Distributed power allocation, Non-convex QCQP, Sum-rate maximization, Algorithms, Cells, Cognitive systems, Communication channels (information theory), Cytology, Iterative methods, Quality of service, Radio systems, Asynchronous algorithms, Cooperative multiple access, Distributed Power-Allocation, Gaussian multiple-access channels, Primary Users, Sum-rate maximizations, Super-position coding
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:kth:diva-176240 (URN)10.1007/s11235-015-0058-x (DOI)000371417000002 ()2-s2.0-84959540807 (Scopus ID)
Note

QC 20151116. QC 20160407

Available from: 2015-11-16 Created: 2015-11-02 Last updated: 2018-01-10Bibliographically approved
Miao, G., Zander, J., Sung, K. W. & Slimane, S. B. (2016). Fundamentals of Mobile Data Networks. Cambridge: Cambridge University Press
Open this publication in new window or tab >>Fundamentals of Mobile Data Networks
2016 (English)Book (Other academic)
Abstract [en]

This unique text provides a comprehensive and systematic introduction to the theory and practice of mobile data networks. Covering basic design principles as well as analytical tools for network performance evaluation, and with a focus on system-level resource management, you will learn how state-of-the-art network design can enable you flexibly and efficiently to manage and trade-off various resources such as spectrum, energy, and infrastructure investments. Topics covered range from traditional elements such as medium access, cell deployment, capacity, handover, and interference management, to more recent cutting-edge topics such as heterogeneous networks, energy and cost-efficient network design, and a detailed introduction to LTE (4G). Numerous worked examples and exercises illustrate the key theoretical concepts and help you put your knowledge into practice, making this an essential resource whether you are a student, researcher, or practicing engineer.

Place, publisher, year, edition, pages
Cambridge: Cambridge University Press, 2016. p. 322
Keywords
Wireless Networks, Wireless Communication, Cellular Systems
National Category
Communication Systems
Research subject
SRA - ICT; Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-185815 (URN)978-1-107-14321-0 (ISBN)
Note

QC 20160623

Available from: 2016-04-28 Created: 2016-04-28 Last updated: 2019-10-11Bibliographically approved
Obregon, E. C., Sung, K. W. & Zander, J. (2016). Is spectrum sharing in the radar bands commercially attractive?: -a regulatory and business overview. European transactions on telecommunications, 27(3), 428-438
Open this publication in new window or tab >>Is spectrum sharing in the radar bands commercially attractive?: -a regulatory and business overview
2016 (English)In: European transactions on telecommunications, ISSN 1124-318X, E-ISSN 2161-3915, Vol. 27, no 3, p. 428-438Article in journal (Refereed) Published
Abstract [en]

The need to meet users' expectations in the 'mobile data avalanche' represents a significant challenge for mobile network operators. More spectrum is a natural way to meet these requirements in a cost and time-efficient way, but new, exclusively licenced spectrum is increasingly hard to come by. Instead, vertical spectrum sharing has been discussed as a potential solution for finding additional spectrum. In this paper, we focus on vertical spectrum sharing in the radar bands for providing short-range wireless access, for example, indoors and in hotspots that 'offload' traffic demand. We propose a methodology for analysing the technical, regulatory and business aspects of deploying large-scale wireless networks. Then, we identify the following criteria for achieving business success: spectrum availability, availability of low-cost end-user devices, system scalability in terms of number of concurrently used devices and finally the ability to guarantee a quality of service for the users. Our technical availability assessment has identified geo-location database as the necessary technical enabler and detect-and-avoid mechanism as an auxiliary enabler for improving sharing conditions. Moreover, licenced shared access was found to be the suitable regulatory framework to support the proposed sharing mechanism and regulatory policies in real-life implementation. Our business feasibility assessment concludes that there is enough spectrum available for indoor and hotspots communication in urban areas in the radar bands to make a large-scale system commercially viable. Service quality can be guaranteed, and there is a strong potential to construct low-cost devices. Uncertainties do, however, remain regarding the spectrum access cost.

Place, publisher, year, edition, pages
John Wiley & Sons, 2016
Keywords
Costs, Large scale systems, Quality of service, Wireless networks, Availability assessment, Feasibility assessment, Geo-location database, Mobile network operators, Real-life implementations, Regulatory frameworks, Spectrum availability, Vertical spectrum sharing, Radar
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:kth:diva-176247 (URN)10.1002/ett.2962 (DOI)000371643900009 ()2-s2.0-84959532789 (Scopus ID)
Note

QC 20160401

Available from: 2015-11-13 Created: 2015-11-02 Last updated: 2018-01-10Bibliographically approved
Piunti, P., Cavdar, C., Morosi, S., Teka, K. E., Del Re, E. & Zander, J. (2015). Energy efficient adaptive cellular network configuration with QoS guarantee. In: 2015 IEEE International Conference on Communications (ICC): . Paper presented at IEEE International Conference on Communications, ICC 2015, London, United Kingdom, 8 June 2015 through 12 June 2015 (pp. 68-73). IEEE conference proceedings
Open this publication in new window or tab >>Energy efficient adaptive cellular network configuration with QoS guarantee
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2015 (English)In: 2015 IEEE International Conference on Communications (ICC), IEEE conference proceedings, 2015, p. 68-73Conference paper, Published paper (Refereed)
Abstract [en]

Cellular network energy optimization is driven by different factors, namely transmission power and activity of the base stations. Quality of Service (QoS) of users is determined by received power, interference and bandwidth allocation and cannot be neglected. In existing studies, such drivers are treated separately, i.e., bandwidth allocation is fixed while power consumption is a variable to be optimized. This paper proposes a novel optimization framework which is aimed at minimizing the power consumption in cellular networks while affording a minimum bit rate for each mobile terminal by jointly considering energy consumption and QoS drivers. Mixed Integer Quadratic Programming (MIQP) based optimization framework solves the problems of the determination of the user association, the bandwidth allocation, the identification of the active base stations and their transmission power, guaranteeing also a requested service rate for each user. The proposed solution is shown to allow power savings of up to 60%, very close to the optimum lower bound, when the traffic is below the 35% of the maximum load.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2015
Series
IEEE International Conference on Communications, ISSN 1550-3607
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-181156 (URN)10.1109/ICC.2015.7248300 (DOI)000371708100012 ()2-s2.0-84953726308 (Scopus ID)978-1-4673-6432-4 (ISBN)
Conference
IEEE International Conference on Communications, ICC 2015, London, United Kingdom, 8 June 2015 through 12 June 2015
Note

QC 20160212, OQ 20160421

Available from: 2016-02-12 Created: 2016-01-29 Last updated: 2016-04-21Bibliographically approved
Shi, L., Sung, K. W. & Zander, J. (2015). Future TV Content Delivery Over Cellular Networks From Urban to Rural Environments. IEEE Transactions on Wireless Communications, 14(11), 6177-6187
Open this publication in new window or tab >>Future TV Content Delivery Over Cellular Networks From Urban to Rural Environments
2015 (English)In: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 14, no 11, p. 6177-6187Article in journal (Refereed) Published
Abstract [en]

With the increasing number of TV channels and the growing need for on-demand services, the traditional digital terrestrial television is becoming a less attractive way of distributing TV content. As an alternative, we discuss a converged platform in the UHF band for TV and mobile broadband provisioning based on LTE cellular technology and infrastructure, which is here referred to as CellTV. The requirement for CellTV is to provide seamless TV coverage from urban to rural environments and to minimize the spectrum requirement so that the leftover can be used for mobile services. We formulate an optimal spectrum allocation problem for CellTV to distribute different TV channels with different transmission modes. Each TV channel is delivered via either unicast links or the broadcast over single-frequency networks of different modulation orders according to the location-dependent viewing demand and the cellular infrastructure availability. Based on a case study of the Greater Stockholm region, we identify that CellTV only requires a small portion of the UHF band to deliver the TV content in urban areas, thus releasing a significant amount of spectra for mobile broadband services. Meanwhile, the spectrum requirement for CellTV is considerably higher in suburban and rural areas due to the transitions of transmission modes. We further generalize these findings to provide a guiding principle for CellTV deployment in mixed environments and to demonstrate the flexibility advantage of CellTV in adapting to the growing diversity of TV content.

Place, publisher, year, edition, pages
IEEE Press, 2015
Keywords
UHF TV band, terrestrial TV broadcasting, multimedia broadcasting/multicast service, single frequency network, unicast video streaming
National Category
Communication Systems Telecommunications
Identifiers
urn:nbn:se:kth:diva-179171 (URN)10.1109/TWC.2015.2449841 (DOI)000365046100022 ()2-s2.0-84959560935 (Scopus ID)
Note

QC 20151214

Available from: 2015-12-14 Created: 2015-12-11 Last updated: 2017-12-01Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4986-6123

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