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  • 151.
    Laya, Andres
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). Universitat Politècnica de Catalunya (UPC), Spain.
    Wang, K.
    Alonso, L.
    Alonso-Zarate, J.
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Supporting Machine-to-Machine Communications in Long-Term Evolution Networks2015In: Machine-to-machine (M2M) Communications: Architecture, Performance and Applications / [ed] Anton-Haro, Carles; Dohler, Mischa, Woodhead Publishing , 2015, p. 109-129Chapter in book (Refereed)
    Abstract [en]

    Abstract This chapter describes key challenges that must be faced to turn long-term evolution (LTE) into a suitable technology for machine-to-machine (M2M) and machine-type communications (MTC). In particular, the challenges dealt with in this chapter relate to managing a large number of devices, attaining very low energy consumption, ensuring low-complexity protocols to bring down the cost of devices, and extending coverage to facilitate one-hop transmissions. Beyond being technically feasible, network operators must adopt network optimization; therefore, a techno-economic perspective is presented in this chapter as well. Business-related requirements and implications that emerge from the traffic mix between humans and machines are covered, including scalability and deployment cost issues, as well as migration options from current solutions.

  • 152.
    Laya, Andres
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Wang, Kun
    Ahmed, Ashraf Awadelkarim Widaa
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Alonso-Zarate, Jesus
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Alonso, Luis
    Device-to-device communications and small cells: Enabling spectrum reuse for dense networks2014In: IEEE wireless communications, ISSN 1536-1284, E-ISSN 1558-0687, Vol. 21, no 4, p. 98-105Article in journal (Refereed)
    Abstract [en]

    In the evolution of communication networks, there has always been a need to increase the capacity to cope with the continuous growing demand for data transmission. However, with the arrival of the Internet-of-Things and the commoditization of broadband access through smartphones, tablets, smart-watches, and all types of connecting devices, future networks must be capable of providing higher bandwidth and Quality of Experience, as wellas operating in dense networks with a massive number of simultaneous connections. This high number of connections will be very heterogeneous, spanning from highly-demanding data rate applications to low-complexity and high energy-efficient Machine-to-Machine communications. In such a dense and complex scenario, a more flexible use of spectrum resources is deemed to be the way to meet the growing requirements for data transmission. In particular, this article focuses on Device-to-Device communications and small cell deployments as emerging facilitators of such a demanding and heterogeneous scenario. The pros and cons of both complementary strategies are identified from both a technical and a business point of view, and main standardization activities are discussed. The aim of this article is to identify and describe open challenges and to inspire new areas for research that make viable the next generation of dense networks.

  • 153.
    Laya, Andrés
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Challenges Adopting Internet-of-Things for Healthcare in SwedenManuscript (preprint) (Other academic)
    Abstract [en]

    PURPOSE: To review how public and private organizations innovate at the convergence of the ICT and the healthcare industries with services based on connected devices in Sweden.

     

    DESIGN/METHODOLOGY/APPROACH: Country case study, using aggregation of primary and secondary data about challenges associated to the adoption of new solutions in the public health and social care systems; taking a business ecosystem approach.

     

    FINDINGS: There are four key challenges affecting innovation based on connected devices and distinctive development patterns of services based on connected devices. For each development pattern, the paper identifies different ways to handle the existing challenges, and it is followed by different types of actors in the business ecosystem.

     

    ORIGINALITY/VALUE: The key contribution of this study is to show how innovative initiatives are addressing the existing challenges by following one of the three distinctive development patterns in Sweden—the public sector, the private sector, or the wellbeing sector.

  • 154.
    Laya, Andrés
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    The Internet of Things in Health, Social Care, and Wellbeing2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Internet of Things (IoT) enables opportunities to remotely sense and control objects via communication networks. We study services based on connected devices and the collaboration they generate between the ICT and the Health, Social Care and Wellbeing (HSCWB) industries.

    In HSCWB, IoT can support a change from episodic treatments of illness to preventive care and wellbeing solutions. The IoT can be a supporter in cost efficient and high quality health care. The objective is to achieve healthier life years and more efficiency in health and social care. Even if the potential of IoT in HSCWB has been proven in pilot projects and small-scale solutions, the benefits and opportunities for many actors are still unclear. There is a research gap in studying the roles and business opportunities for market-driven technology-based solutions enabled by connected devices.

    The research approach separates technological and business domains. On the technology side, the focus is on advances in connectivity for IoT. We present the technical details on a limitation to support IoT devices in cellular networks. We quantify the limitations in the Random Access Channel of the LTE air interface to support IoT devices. Moreover, we propose the adaptation of an access mechanism to enable massive number of simultaneous access attempt in cellular networks.

    On the business side, we identify and present how the conditions of the health and social care structure in Sweden affect the establishment of IoT solutions in HSCWB. We then show how these conditions have generated three distinctive development patterns—to innovate within the public sector, to develop solutions in the private care sector, or to target the wellbeing sector to avoid regulatory setbacks.

    Based on these patterns, we look closer into study cases to show how business opportunities have been addressed from a business network perspective. When deploying an IoT service, not all critical challenges can be appreciated at a single firm level. Therefore, we rely on a network-level business model framework to analyze emerging IoT services in HSCWB.

    The findings suggest that IoT components can improve an existing service by automating internal working processes, or they can enable new value propositions and convenience to end users. In general terms, the collaboration can be used (i) to improve the efficiency of existing services in health and social care without an original intention to change the service offering, or (ii) to create novelty and differentiation, without affecting the internal logics of existing HSCWB services.

  • 155.
    Laya, Andrés
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    The M2M promise, what could make it happen?2013In: 2013 IEEE 14th International Symposium on a World of Wireless, Mobile and Multimedia Networks, WoWMoM 2013, IEEE , 2013, p. 6583489-Conference paper (Refereed)
    Abstract [en]

    Machine-to-Machine (M2M) communications is a topic of great importance that maintains an ongoing interest in the academic community and in countless industries and services. Technological advances allow the successful deployment of particular solutions but many potential applications still face limitations that prevent them from happening. This paper compares data collected from five implementation cases in order to analyze key issues related to their value proposition and the challenges that currently limit the adoption of M2M communications.

  • 156.
    Laya, Andrés
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Lundberg, Stefan
    KTH, School of Technology and Health (STH), Health Systems Engineering, Ergonomics.
    Network-Centric Business Models for Health, Social Care and Wellbeing Solutions in the Internet of ThingsManuscript (preprint) (Other academic)
    Abstract [en]

    In this multiple case study we analyze solutions based on connected devices in the context of health, social care and wellbeing. Based on the consideration that a solution is a combination of services and products, we build on the notion that business models can be studied at a firm- and a network-level. These two levels are used to motivate the reasons why solutions emerging at the intersection of the healthcare and the ICT industries benefit from collaboration among different actors. We conclude that the firm- and the network-level development of business models provide alignment in the business network and are useful to establish the relation that technological component have with overall solutions. Our findings suggest that some component bring novelty in the final offer with affecting the ongoing operation, while other component aim at improving the internal working processes, with minimal effects on the final offer to end users. We discuss the benefits of a network-level perspective for each case.

  • 157.
    Laya, Andrés
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). u18hwyj1.
    Sundquist, Mårten
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Motivation, Regulation And Actor Constellations - Experiences From A Multidisciplinary Research Project On Health And Wellbeing As Part Of The Internet Of Things2015Conference paper (Refereed)
    Abstract [en]

    Internet of Things is an inherently multi-disciplinary area, as mobile connectivity, sensor device technologies and cloud solutions make strong impact in a multitude of applications in diverse sectors. In this paper we study some technical solutions, business models and behavior aspects of IoT in a Health and Wellbeing context. The work is based on an ongoing research project initiated by a wireless research center. This project includes two startup-up companies that are developing services based on connected devices. As part of the evaluation activities, the project counts with the collaboration of the largest nonprofit training organization in Sweden. As part of the research project, a prototype application is developed for training. Leveraging on the insights related to the individual motivational aspects, collected from an end-user study on motivational and adoptability aspects of Internet of Things in a workout context. In order to better understand the context on which services are provided, an ecosystem analysis is elaborated in order to highlight the differences between the healthcare and wellbeing contexts.

  • 158.
    Laya, Romero Andres
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Alonso, L.
    Alonso-Zarate, J.
    Contention resolution queues for massive machine type communications in LTE2015In: 2015 IEEE 26th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), Institute of Electrical and Electronics Engineers (IEEE), 2015, p. 2314-2318Conference paper (Refereed)
    Abstract [en]

    In this paper, we address the challenge of high device density performing simultaneous transmissions by proposing and evaluating a solution to efficiently handle the initial access contention for highly dense LTE networks. We present the implementation of a tree-splitting algorithm in the access procedure of LTE, which is capable to cope with high number of simultaneous arrivals. Based on simulations we show a feasible implementation capable to achieve, under certain network configuration conditions, up to 85% average access delay reduction and 40% reduction on the average energy consumption, while maintaining a consistently low blocking probability, regardless of the number of initial simultaneous access attempts.

  • 159.
    Lee, Sabine
    et al.
    Department of Physics, Stockholms University.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Dynamic PET visualization of bone remodeling using NaF-182015Report (Other academic)
    Abstract [en]

    Positron emission tomography (PET) studies acquired in list mode offer the opportunity to provide a cine loop showing the dynamics of 18F- PET uptake, giving a visualization of regional bone remodeling. The focus of this report is a group of patients treated with Taylor spatial frames (TSF). The studies were acquired for a period of 45 minutes and saved in list mode. The list was decoded and subsequently segmented into time intervals of one minute each. For each time interval a sinogram was generated from which volumes of one minute each were reconstructed. Slices projected from these volumes could then be displayed as a dynamic loop superimposed on the corresponding computed tomography (CT) slice in order to visualize the 18F- uptake insitu. It was indicated that this technique has the potential of becoming an additional technique to that of using static volumes and SUV values only.

    As the list mode data was decoded it also offered a method to evaluate the potential decrease in injected activity by eliminating every Nth event from the list before reconstructing the 45 minute volume. This was done and the indication was that the injected activity and hence the effective dose to the patient can be decreased. However, in this work, this was not proven clinically.

    The open source STIR software was used to reconstruct volumes from sinograms to enable an unlimited access to reconstructing volumes without disturbing the daily routine at the clinic. The data was acquired on a clinical Siemens Medical Solutions Biograph 64 TruePoint TrueV, PET/CT scanner situated at the Nuclear Medicine Department at the Karolinska University Hospital in Solna. This scanner was not supported by the STIR software, hence the data collected by the Siemens PET/CT scanner was translated so that 3D reconstructions could be computed using the STIR tools. The reconstructions made in STIR resulted in volumes of sufficient visual quality, but not as good as those reconstructed by the scanner itself. Further optimization in STIR was left for future work.

    According to the physicians who treat these patients, dynamic visualization was of sufficient interest to continue to develop and optimize this method. The cine loops that were presented to the physicians were made from JPEG slices produced from the one minute volumes and put together as GIF files. It was also possible to vary the reconstruction time (from uniformly one minute) as well as the presentation rate in the cine loop, but this was left for future work. Ultimately, the cine loop will be implemented in the locally developed software tool.

  • 160.
    Lejeune, Ruben
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Adding citations to PowerPoint slides from Zotero: Making referencing in PowerPoint easier2015Report (Refereed)
    Abstract [en]

    When writing papers, it is frequently necessary to add citations. A frequently used tool to facilitate this process is Zotero. Currently one can add citations using the Zotero Word integration extension to a Word document, however there is not yet a tool to do so in PowerPoint – despite the fact that in many settings this would be very desirable. This project solves this problem.

    The first difficulty was that this was the first time I had to analyze a software project of this magnitude (specifically the Zotero and Zotero Word integration software). This meant I had to understand their structure and find out what pieces of the software would be useful to me. The second difficulty was to understand and use some of the tools used by Zotero and Zotero Word integration as they were new to me, specifically: creating add-ins for Powerpoint (in VBA), creating Firefox extensions, and working with C++.

    The goal of this project was to enable users to add citations to PowerPoint with an easy to use interface. Additionally, users can now with a single button click automatically generate slides at the end of the presentation with all the references.

  • 161. Lema, Maria A.
    et al.
    Laya, Andres
    Mahmoodi, Toktam
    Cuevas, Maria
    Sachs, Joachim
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Dohler, Mischa
    Business Case and Technology Analysis for 5G Low Latency Applications2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5, p. 5917-5935Article in journal (Refereed)
    Abstract [en]

    A large number of new consumer and industrial applications are likely to change the classic operator's business models and provide a wide range of new markets to enter. This paper analyzes the most relevant 5G use cases that require ultra-low latency, from both technical and business perspectives. Low latency services pose challenging requirements to the network, and to fulfill them, operators need to invest in costly changes in their network. In this sense, it is not clear whether such investments are going to be amortized with these new business models. In light of this, specific applications and requirements are described and the potential market benefits for operators are analyzed. Conclusions show that the operators have clear opportunities to add value and position themselves strongly with the increasing number of services to be provided by 5G.

  • 162.
    Liu, Enfei
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    USB dongles for mobile broadband: Data communications for laptop computers2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today a growing number of people need to work on laptops with wireless Internet connection. There are two common wireless Internet access solutions: wireless local area network (WLAN) via hotspot, and high speed wide area cellular network via mobile broadband device such as 3G/4G Universal Serial Bus (USB) dongle. USB dongle was the pioneer product in 3G/4G market, and it is still a popular device in many countries. Mobile broadband can offer both high speed access and mobility. Technically mobile broadband allows Internet connection as long as your mobile transceiver can access your cellular network operator’s network. However, in practice the data rates experienced by a user via mobile broadband are not comparable to the data rates that are available via WLAN. Moreover, mobile broadband has been implemented according to multiple different standards. Hence, in order to provide a user with locally optimal service requires that user must make use of heterogeneous networks. Furthermore, the variety of networks gets increasing due to the emergence of various 4G networks.

    The aim of this thesis is to explore how heterogeneous networks could be exploited to provide a user of a laptop computer with locally optimal service, while hiding the complexity of this heterogeneous service. The research focuses on the implications of integrating multiple network interfaces into a single USB dongle. Our research shows that multi-mode USB dongle is still needed in market, though there are competitions from smartphones and mobile WiFi devices. We point out that the PPP (Point to Point Protocol) based USB dongle should update to Ethernet USB protocols such as RNDIS (Remote Network Driver Interface Specification) or USB CDC (Communications Device Class) protocols. Furthermore, we suggest a USB dongle should be able to work as a WLAN access point to share Internet with other mobile devices, and it should also work as a WLAN client which can join other hotspots. If hotspot operators can authenticate USB dongles by SIM cards, then users can easily access a great number of hotspots belong to these operators.

  • 163. Liu, Fei
    et al.
    Riihijarvi, Janne
    Petrova, Marina
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). RWTH Aachen University, Germany.
    Analysis of Proportional Fair Scheduling Under Bursty On-Off Traffic2017In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 21, no 5, p. 1175-1178Article in journal (Refereed)
    Abstract [en]

    Proportional fair scheduling (PFS) has been adopted as a standard solution for fair resource allocation in modern wireless cellular networks. With the emergence of heterogeneous networks with widely varying user loads, it is of great importance to characterize the performance of PFS under bursty traffic, which is the case in most wireless streaming and data transfer services. In this letter, we provide the first analytical solution to the performance of PFS under bursty on-off traffic load. We use the Gaussian approximation model to derive a closed-form expression of the achievable user data rates. In order to further improve the accuracy of our baseline analytical solution for multi-cell networks, we design a hybrid approximation by employing multi-interference analysis. The simulation results verify that our model guarantees extremely low data rate estimation error, which is further insensitive to changes in session duration, traffic load and user density.

  • 164.
    Lundblad, Henrik
    et al.
    Karolinska Institute, Stockholm, Sweden.
    Karlsson-Thur, Charlotte
    Karolinska Institute, Stockholm, Sweden.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Jonsson, Cathrine
    Karolinska University Hospital, Stockholm, Sweden.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Zeleznik, Michael P.
    University of Utah.
    Weidenhielm, Lars
    Karolinska Institutet at Karolinska University Hospital Solna.
    Can Spatiotemporal Fluoride (18F-ˆ’) Uptake be Used to Assess Bone Formation in the Tibia?: A Longitudinal Study Using PET/CT2017In: Clinical Orthopaedics and Related Research, ISSN 0009-921X, E-ISSN 1528-1132, Vol. 475, no 5, p. 1486-1498Article in journal (Refereed)
    Abstract [en]

    When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bone healing is progressing. There has been resurgence in the use of the fluoride (18F-ˆ’) ion to evaluate various bone conditions. This has been made possible by availability of positron emission tomography (PET)/CT hybrid scanners together with cyclotrons. Absorbed on the bone surface from blood flow, 18F-ˆ’ attaches to the osteoblasts in cancellous bone and acts as a pharmacokinetic agent, which reflects the local physiologic activity of bone. This is important because it shows bone formation indicating that the bone is healing or no bone formation indicating no healing. As 18F-ˆ’ is extracted from blood in proportion to blood flow and bone formation, it thus enables determination of bone healing progress.

  • 165.
    Lundblad, Henrik
    et al.
    Karolinska Institutet, Sweden.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Karlsson-Thur, Charlotte
    Karolinska Institutet, Sweden.
    Jonsson, Cathrine
    Karolinska University Hospital Solna, Sweden.
    Noz, Marilyn E.
    New York University, USA.
    Zeleznik, Michael P.
    University of Utah, USA.
    Jacobsson, Hans
    Karolinska Institutet, Sweden.
    Weidenhielm, Lars
    Karolinska Institutet, Sweden.
    Using PET/CT Bone Scan Dynamic Data to Evaluate Tibia Remodeling When a Taylor Spatial Frame Is Used: Short and Longer Term Differences2015In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, Vol. 2015, p. 1-11, article id 574705Article in journal (Refereed)
    Abstract [en]

    Eighteen consecutive patients, treated with a Taylor Spatial Frame for complex tibia conditions, gave their informed consentto undergo Na18F− PET/CT bone scans. We present a Patlak-like analysis utilizing an approximated blood time-activity curveeliminating the need for blood aliquots. Additionally, standardized uptake values (SUV) derived from dynamic acquisitions werecompared to this Patlak-like approach. Spherical volumes of interest (VOIs) were drawn to include broken bone, other (normal)bone, and muscle. The SUV𝑚(𝑡) (𝑚 = max, mean) and a series of slopes were computed as (SUV𝑚(𝑡𝑖) − SUV𝑚(𝑡𝑗))/(𝑡𝑖 − 𝑡𝑗), forpairs of time values 𝑡𝑖 and 𝑡𝑗. A Patlak-like analysis was performed for the same time values by computing ((VOI𝑝(𝑡𝑖)/VOI𝑒(𝑡𝑖)) −(VOI𝑝(𝑡𝑗)/VOI𝑒(𝑡𝑗)))/(𝑡𝑖−𝑡𝑗), where p = broken bone, other bone, andmuscle and e = expected activity in aVOI. Paired comparisonsbetween Patlak-like and SUV𝑚 slopes showed good agreement by both linear regression and correlation coefficient analysis(𝑟 = 84%, 𝑟𝑠 = 78%-SUVmax, 𝑟 = 92%, and 𝑟𝑠 = 91%-SUVmean), suggesting static scans could substitute for dynamic studies.Patlak-like slope differences of 0.1 min−1 or greater between examinations and SUVmax differences of ∼5 usually indicated goodremodeling progress, while negative Patlak-like slope differences of −0.06 min−1 usually indicated poor remodeling progress in thiscohort.

  • 166.
    Lundblad, Henrik
    et al.
    Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden .
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Olivecrona, Henrik
    Karolinska Institute.
    Jonsson, Cathrine
    Department of Medical Physics, Karolinska University Hospital, Stockholm, Sweden.
    Jacobsson, Hans
    Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden .
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Zeleznik, Michael P.
    University of Utah.
    Weidenhielm, Lars
    Karolinska Institutet at Karolinska University Hospital Solna.
    Sundin, Anders
    Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden .
    Can Na18F PET/CT Be Used to Study Bone Remodeling in the Tibia When Patients Are Being Treated with a Taylor Spatial Frame?2014In: Scientific World Journal, ISSN 1537-744X, E-ISSN 1537-744X, Vol. 2014, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Monitoring and quantifying bone remodeling are of interest, for example, in correction osteotomies, delayed fracture healing pseudarthrosis, bone lengthening, and other instances. Seven patients who had operations to attach an Ilizarov-derived Taylor Spatial Frame to the tibia gave informed consent. Each patient was examined by (NaF)-F-18 PET/CT twice, at approximately six weeks and three months after the operation. A validated software tool was used for the following processing steps. The first and second CT volumes were aligned in 3D and the respective PET volumes were aligned accordingly. In the first PET volume spherical volumes of interest (VOIs) were delineated for the crural fracture and normal bone and transferred to the second PET volume for SUVmax evaluation. This method potentially provides clinical insight into questions such as, when has the bone remodeling progressed well enough to safely remove the TSF? and when is intervention required, in a timelier manner than current methods? For example, in two patients who completed treatment, the SUVmax between the first and second PET/CT examination decreased by 42% and 13%, respectively. Further studies in a larger patient population are needed to verify these preliminary results by correlating regional (NaF)-F-18 PET measurements to clinical and radiological findings.

  • 167.
    Lundblad, Henrik
    et al.
    Karolinska Institute, Department of Molecular Medicine and Surgery.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Jonsson, Cathrine
    Karolinska University Hospital Solna, Department of Medical Physics.
    Jacobsson, Hans
    Karolinska Institute.
    Sundin, Anders
    Karolinska Institute, Department of Molecular Medicine and Surgery.
    Preliminary Results of Studying Bone Growth Using NaF-18 in Patients with aTaylor Spatial Frame (TSF)2013Conference paper (Refereed)
    Abstract [en]

    We were able to see the difference in bone activity ofdifferent parts of the leg over the course of a patient’s therapy. In one patient, we detected at 52 days that the fibula had an SUVmax of 66 while the tibia had an SUVmax of 14, indicating that the fibula was healing much faster than the tibia. The surgeon had to intervene, re-breaking and distracting the fibula. At 94days after the initial surgery, both bones had a more comparable activity (with an SUVmax of 37 and 24 respectively). This study has lead to the use of PET/CT imaging to assess the early clinical state of the bone remodelling process.

  • 168.
    Maguire Jr., Gerald Q.
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Olivecrona, Henrik
    Karolinska Institute.
    Zeleznik, Michael P.
    University of Utah, Salt Lake City, UT, USA.
    Weidenhielm, Lars
    Karolinska Institute.
    A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis2014In: Scientific World Journal, ISSN 1537-744X, E-ISSN 1537-744X, Vol. 2014, p. 528407-Article in journal (Refereed)
    Abstract [en]

    As the most advantageous total hip arthroplasty (THA) operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT) volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD) of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (+/- SD) for the diameter of the acetabular cup of 54.21 (+/- 0.011) mm and for the femoral component head of 22.09 (+/- 0.02) mm. The wear error was +/- 0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction.

  • 169. Malik, J. S.
    et al.
    Ben Slimane, Slimane
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Hemani, Ahmed
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Gohar, N. D.
    Improving performance of fading channel simulators by use of Uniformly distributed Random Numbers2011In: 2010 IEEE International Symposium on Signal Processing and Information Technology, 2011, p. 91-96Conference paper (Refereed)
    Abstract [en]

    Filter-based fading channel simulators universally use White Gaussian Noise (WGN) to generate complex tap coefficients. In this work, we will show that replacing WGN source by Uniform Random Number Generator (URNG) results in improved simulation speed in case of software simulator; and reduced area/power in case of hardware simulator. We will verify, both analytically and through extensive simulations, that use of URNG does not cause any degradation in important simulator performance parameters like statistical properties, spectral shape, level crossing rate and bit error rate. To validate our analysis, we have designed fading channel simulators both in software and hardware. We will show that use of URNG causes 6 percent improvement in simulation time in case of software simulator. Similarly, we will demonstrate that for a hardware simulator, we obtain an improvement of 30 and 40 percent in area and power consumption respectively.

  • 170.
    Malik, Jamshaid Sarwar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronics and Embedded Systems.
    Hemani, Ahmed
    KTH, School of Information and Communication Technology (ICT), Electronics and Embedded Systems.
    Malik, J. N.
    Silmane, Ben
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Gohar, N. D.
    Revisiting central limit theorem: Accurate Gaussian random number generation in VLSI2015In: IEEE Transactions on Very Large Scale Integration (vlsi) Systems, ISSN 1063-8210, E-ISSN 1557-9999, Vol. 23, no 5, p. 842-855, article id 6834810Article in journal (Refereed)
    Abstract [en]

    Gaussian random numbers (GRNs) generated by central limit theorem (CLT) suffer from errors due to deviation from ideal Gaussian behavior for any finite number of additions. In this paper, we will show that it is possible to compensate the error in CLT, thereby correcting the resultant probability density function, particularly in the tail regions. We will provide a detailed mathematical analysis to quantify the error in CLT. This provides a design space with more than four degrees of freedom to build a variety of GRN generators (GRNGs). A framework utilizes this design space to generate customized hardware architectures. We will demonstrate designs of five different architectures of GRNGs, which vary in terms of consumed memory, logic slices, and multipliers on field-programmable gate array. Similarly, depending upon application, these architectures exhibit statistical accuracy from low (4 σ ) to extremely high (12 σ). A comparison with previously published designs clearly indicate advantages of this methodology in terms of both consumed hardware resources and accuracy. We will also provide synthesis results of same designs in application-specific integrated circuit using 65-nm standard cell library. Finally, we will highlight some shortcomings associated with such architectures followed by their remedies.

  • 171. Manssour, J.
    et al.
    Ahsin, Tafzeel ur Rehman
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Slimane, Ben
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Osseiran, A.
    Analysis and performance of network decoding strategies for cooperative network coding2013In: Physical Communication, ISSN 1874-4907, E-ISSN 1876-3219, Vol. 6, p. 48-61Article in journal (Refereed)
    Abstract [en]

    In this work, we present two new low-complexity network decoding strategies for cooperative network coding in a multiple-access relay channel scenario. For these two strategies, Selection and Soft Combining and Majority Vote Network Decoding, along with the optimal joint network decoding, we derive expressions for bit error probability performance as a function of the signal-to-noise ratio (SNR) of the different Rayleigh fading links, and show the tightness of the derived bounds through simulation results. The two proposed schemes provide a similar bit error probability (BEP) performance compared to the optimal scheme, while having significantly lower complexity. Further, we study the effect of user pairing on the error performance by considering different SNRs on the user and relay links towards the destination. It is also shown that the error performance of the different schemes follows the same trend for a given user pairing strategy.

  • 172.
    Markendahl, Jan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Ahmed, Ashraf Awadelkarim Widaa
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Mölleryd, Bengt G
    PTS, Swedish Post and Telecom Authority,.
    Business models and Investment options for use  of Licensed Shared Access of Spectrum2013Conference paper (Other academic)
    Abstract [en]

    A Licensed Shared Access (LSA) “authorization/license” includes an agreement between the secondary sharing user (some type of operator) and the primary license holder (e.g. a government organization) around the conditions of use (where, when, how).  Compared to secondary access LSA offers a more attractive case for long term investments.  The contribution in this paper is that we look into how LSA can be used by different types of actors. The outcome depends heavily on what type of actor that makes use of the spectrum using LSA. Based on cost structure analysis (leading to required investments) and analysis of availability of the basic spectrum resource we can identify clear differences of the commercial usability of spectrum awarded using LSA, all depending on what actors that make use of the LSA contract. Cases where new actors need to invest a lot in new infrastructure do not that look that promising. We cannot identify a separate “LSA business case” that is feasible from a business perspective (where the key resource for the operator is spectrum awarded using LSA).  Service availability that cannot be guaranteed due to LSA type of spectrum being the only resource seems risky, especially when combined with high investments. However this applies only for outdoor deployment. For deployment of a new indoor network the situation is different. The cost structure is the same no matter if a new or existing actor deploys the networks. In addition, a multitude of spectrum bands and spectrum access options exist indoor so the service provisioning will be less vulnerable if some part of spectrum is not available some period of time. 

  • 173.
    Markendahl, Jan
    et al.
    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, Radio Systems Laboratory (RS Lab).
    Apanasevic, Tatjana
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Mobile operator strategies to enter or stay in the market of mobile payment services: Teaching Notes2013In: The 29th Annual IMP Conference (IMP2013) proceedings: Building and Managing Relationships in a Global Network: Challenges and Necessary Capabilities / [ed] Minna Rollins and Brian Rutherford, IMP Group , 2013Conference paper (Refereed)
    Abstract [en]

    The case is to be used for identification, selection and analysis of company strategies with focus on decision making for companies providing mobile services. The target groups are both managers in the industry as well as master level students in areas like business administration, industrial marketing, industrial economy, and information and communication The work using the case includes a group exercise with identification and analysis of different strategy options for a sequence of events where market conditions change.

    In the case the students will represent the management of a mobile network operator (MNO) that needs to adapt to market changes related to mobile payment services. An ccompanying, but totally different, case covers the use of mobile payment services by big retailers.

  • 174.
    Markendahl, Jan
    et al.
    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.
    Apanasevic, Tatjana
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Trends towards fragmentation of the mobile payment market in Sweden2013In: The 29th Annual IMP Conference (IMP2013) proceedings: Building and Managing Relationships in a Global Network: Challenges and Necessary Capabilities / [ed] Minna Rollins and Brian Rutherford, IMP Group , 2013Conference paper (Refereed)
    Abstract [en]

    In Sweden many new mobile payment solutions and services have been proposed during the last years. Banks and payment providers have proposed different forms of person to person (P2P) and Point of Sales (PoS) services that are tested and taken into commercial use. The Swedish mobile operators have joined forces and formed a joint venture that offers a separate charging solution that can be used for mobile payments and e-commerce, i.e. not using the phone bill. Early 2013 the SMS ticket for public transportation was changed substantially with the entrance of many new actors. 

    In this paper we use the ARA model (Activities, Resources and Actors) in order to analyse the new mobile payment solutions and services looking into the activities, roles and responsibilities of different actors. We also apply the activity system approach describing the Activity system content, structure and governance and activity design themes indicating the main value creation drivers. The analysed cases include mobile payment services for P2P transactions, payments in shops, and ticketing for public transport and parking. The technology, services, and new constellations of actors seem to work fine but there are challenges for the adoption of new services both due to both the multitude of solutions as well as the need to register and manage new user accounts with the payment providers offering new solutions.

  • 175.
    Markendahl, Jan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Apanasevic, Tatjana
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Arvidsson, Niklas
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Entrepreneurship and innovation.
    Mobile ticketing: It is not only about 'cashlessness"2013In: Proceedings of the Second International Cashless Society Roundtable (ICSR): 17 & 18, 2013 / [ed] Fergal Carton and Jonas Hedman, 2013, p. 20-22Conference paper (Refereed)
    Abstract [en]

    A mobile payment service is much more than the transaction, the payment is one part but other types of services and values can be added. In a Swedish research project with public transportation companies KTH researchers look into mobile services for the public transport. The mobile services include integrated solutions for information services, ticketing and payments. For the public transport sector, payment and ticket solutions is one way to attract new types of customers, to decrease barriers for users and to increase the use of public transport in general. These mobile services mainly target segment that do not use public transport on a daily basis, both car drivers (that never or seldom use public transport) and those that quite often (but not always) use public transport. From a research perspective, it is interesting to study mobile services for public transport since it is used by many persons – and often. If mobile payments can take off in this area it may be an “island” that can grow.

  • 176.
    Markendahl, Jan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Ghanbari, Amirhossein
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Shared smallcell networks: Multi-operator or third party solutions - Or both?2013In: 2013 11th International Symposium and Workshops on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks, WiOpt 2013, New York: IEEE , 2013, p. 41-48Conference paper (Refereed)
    Abstract [en]

    Network sharing is a commonly used solution for macro cellular networks when mobile operators want to exploit benefits of sharing infrastructure, typically to save network costs. For local area and indoor networks infrastructure sharing using distributed antenna systems (DAS) and repeaters are commonly used solutions to improve indoor coverage. For these applications multi-operator solutions are well known and supported by both standardization bodies and by collaboration practices. However, when local networks are discussed in terms of femtocell solutions, offloading or heterogeneous networks, the multi-operator context seems to be forgotten. Small cells are often presented in a single-operator context. This does not comply with market demand and practices, since facility owners neither want one single mobile operator to dominate the capacity provision nor accept multiple indoor infrastructures provided by multiple mobile operators. In this paper we will discuss the business model implications of different multi-operator solutions for indoor deployment. The key findings are in the areas of: i) how multi-operator small cell solutions can fit into existing market practices when it comes to operator business, ii) how local network operators (3rd parties) and outsourcing can play a role in the business landscape, and iii) how different (novel) spectrum allocation and access strategies can play a role for indoor network deployment.

  • 177.
    Markendahl, Jan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Ghanbari, amirhossein
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Mölleryd, Bengt G.
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Network cooperation between mobile operators: why and how competitors cooperate?2013In: IMP Conference 2103, 2013Conference paper (Refereed)
    Abstract [en]

    After year 2000 with the introduction of third generation (3G) mobile networks a new type ofcooperation between competitors emerged, network sharing. Cost reduction is often mentionedas the main driver for network sharing. However, cost aspects are only part of the story “why”operators cooperate. In this paper we discuss multiple aspects of “why” operators cooperate andalso “how” competing mobile operators cooperate.Besides cost the “why” aspect is discussed in terms of market position, market entry andexploitation of the resources and skills of the sharing partner but also drawbacks of sharing. Thepatterns of cooperation are illustrated by analyzing how roles, responsibilities and resources canbe distributed among the mobile operators. The findings are based on case studies where wemake comparison in three different domains. In the time domain we compare network sharing inSweden the years 2000 and 2010. From a cost perspective the drivers to share networks havedecrease since many base station sites can be re-used. Anyway, new network sharing companiesare formed in order to make the network operation more efficient.We also compare cooperation between operators at the Swedish and Indian mobile markets. Inboth countries the competition is very strong. Network sharing is used but in India thecooperation is organized through tower companies, hence the operator cooperation is weak.Finally we look into network sharing principles for indoor network deployment in Sweden. Thecooperation between operators is strong but not as strong as for the network sharing jointventures. The tie between two operators can be said to be weaker since several mobile operators,the facility owner and also enterprises may be included in cooperation. In addition theinvestment risk is lower.

  • 178.
    Markendahl, Jan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Laya, Andres
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Transformation of home care services, related working processes and business models due to introduction of mobile technology2014In: Transformation of home care services, related working processes and business models due to introduction of mobile technology, IMP , 2014Conference paper (Refereed)
  • 179.
    Markendahl, Jan
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Laya, Andrés
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Business Challenges for Internet of Things: Findings from e-Home Care, Smart Access Control, Smart Cities and Homes2013Conference paper (Refereed)
    Abstract [en]

    Services based on the Internet of Things (IoT) and Machine to Machine (M2M) communications are actively being proposed for several industries. A lot of initiatives are presented for smart cities, smart homes and smart energy systems. But even with advances in new technology and substantial amount of research funding, most of these services are not deployed on a large scale. Innovation is not needed only for the technical solutions but also for the business models and how actors cooperate.In this paper, a number of projects on smart cities, smart homes and energy systems are presented and compared with some successful cases where new IoT and M2M concepts have been applied. Also, an analysis in presented for the benefits and values that can be identified for different IoT services, including cost saving in service provisioning and ease of use for end-users. It is also studied how drivers, such as improvement in resource utilization, are often hampered by the unwillingness of traditional actors to share a service platform, afraid of losing control over their customers.Examples show how the business models changed or need to be changed. The co-existence of services from parallel sectors and within the same sector is studied in this paper and further compared with a case of competing solutions for the same service (mobile parking). The application of new technology entails changes in the organization of actors; this paper reveals the decreased relevance of some traditional actors, like communication providers, in the service delivery when IoT and M2M solutions are adopted.

  • 180. Marques, P.
    et al.
    Rodriguez, J.
    Forde, T.
    Doyle, L.
    Sung, Ki Won
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Lauterjung, J.
    Reimers, U. H.
    Towards a Unified 5G Broadcast-Broadband Architecture2015In: Fundamentals of 5G Mobile Networks, Wiley-Blackwell, 2015, p. 191-206Chapter in book (Other academic)
    Abstract [en]

    TV broadcasting and mobile broadband are undoubtedly essential parts of today's society. Both of them are now facing tremendous challenges to cope with the future demands. In the United Kingdom, Germany, Ireland and Poland the digital satellite platform is the largest TV platform. However, regardless of whether consumers are using digital satellite or DTT to receive their TV content, neither of these platforms currently meets the needs of a growing non-linear, truly on-demand consumption paradigm. Both satellite and High-Power High-Tower Digital TV (DTV) infrastructure have been designed for a one-to-many architecture with limited scope for feedback channels and user-controlled scheduling, especially in mobile and portable situations. Hybrid approaches including mobile broadband are, however, developing progressively in a large number of countries. TV and mobile broadband have strong similarities in their challenges. Moreover, the recent trend in TV consumption patterns suggests that the TV of the future will be quite similar to the mobile broadband of the coming years in many aspects. Both services have to provide the customer with (ultra-)high quality video in a dynamic and interactive manner. This necessitates an efficient solution for converged broadcast and mobile broadband services. In order to address these challenges, some candidate network architectures for future terrestrial TV distribution have been proposed, including a clean-slate approach (all broadband), hybrid and common converged system. However, it is suggested that substantial further study is required to evaluate the benefit of these architectures and to develop a better solution out of the existing ones. In this chapter, we emphasise the current challenges facing the broadcasting and mobile industries to deliver next generation TV services, and provide an overview of these architectures that could potentially be adopted to provide a 'win-win' Broadcast-Broadband (BC-BB) convergence solution for 5G networks.

  • 181.
    Martinez Ballesteros, Luis Guillermo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    On the Incorporation of Quality of Experience (QoE) in Mobile Networks: A technical, regulatory and business analysis2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Mobile operators face a scenario characterised by new challenges such as growing data consumption, a slowdown in subscriber growth and reduced revenues due to the success of OTT providers. To remain competitive, mobile operators must offer affordable services and think on strategies to retain current customers.

    Quality of Experience (QoE) is a well-established methodology for measuring and understanding the overall level of customer satisfaction with a service and has been presented as a way to improve telecommunication services. Even though QoE can be used to solve problems such as customer loyalty and optimisation of network resources in mobile networks, there is a great lack of knowledge on how mobile operators can take advantage of QoE and its potential benefits.

    This thesis explores the incorporation of QoE in mobile networks to improve their service offering from a technical, regulatory and business perspective.The technical level focuses on the definition of the mechanism to integrate QoE in the operation of mobile networks. The second part of this study has been focused on the regulatory framework on Net Neutrality. Finally,the third part of this thesis focuses on the identification of potential business scenarios and models based on the incorporation of QoE in mobile networks. An important conclusion is that due to the nature of the challenges faced by the mobile industry, a QoE analysis cannot be limited to a technical discussion. A technical solution can be the first step to the first step to overcoming industry challenges. However, it is important that a technical decision comes along with an informed analysis of the regulatory conditions and the business implications of the proposed solution. On the other hand, mobile operators require new methods that integrate technical, market and business considerations to improve their service offer. A method analysed in this dissertation is a Customer Experience Management (CEM) platform. Given the technical, regulatory and business factors covered in this thesis, a CEM platform can be used by mobile operators to make a better use of QoE in their business operation.

  • 182.
    Martinez Ballesteros, Luis Guillermo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Mobile Service Laboratory (MS Lab).
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Lungaro, Pietro
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Mobile Service Laboratory (MS Lab).
    Segall, Zary
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Mobile Service Laboratory (MS Lab).
    Towards a Semantic-aware Radio Resource Management2013In: MOBILITY 2013, The Third International Conference on Mobile Services, Resources, and Users: Proceedings of The Third International Conference on Mobile Services, Resources, and Users, 2013, p. 16-19Conference paper (Refereed)
    Abstract [en]

    In this paper semantic-aware model for radio resource management in wireless networks is introduced and studied through simulation. By semantic-awareness, the network can selectively manage the radio resource allocation based on the evaluation of transferred content, and its associated processing, and prioritize users that are close to experience interruptions, in order to improve the wireless resource utilization and the user’s Quality of Experience (QoE). Different radio resource management (RRM) strategies are proposed and investigated, considering buffer capacity at the terminals and the experience of the users in time while watching a video and waiting for resource allocation. The simulation results show that the users can reduce the total duration, frequency and length of the interruptions during a playback by applying semantic-awareness in the radio resource allocation, which might affect positively user’s QoE.

  • 183.
    Martinez, Luis
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Hossain, Mohammad Istiak
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Markendahl, Jan
    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, Radio Systems Laboratory (RS Lab).
    M2M Communications in Developing Countries2014Conference paper (Refereed)
    Abstract [en]

    M2M sector is an increasingly important source of connections growth for mobile operatorsworldwide. Operators are looking at M2M as a new business alternative means to reduce the impact of theslowing growth (or declines) in traditional consumer mobile services. As a result, many operators areadapting their organisational structures and business models exploring opportunities to expand theirportfolio to emerging markets in developing countries. These markets are still in process of maturing,with M2M implementations at very early stage. On the other hand, the benefits that could accrue todeveloped countries through the Internet of Things (IoT) and machine type communication (MTC) arenumerous. In this context, this paper presents an initial study about the current status of M2M in somedeveloping countries, considering as study cases regions such as Latin America and Asia. Presentedinformation remarks the potential of the considered markets to boost the growth of M2M solutionsworldwide. Finally, we show some specific requirements for M2M business models for developingcountries and a description of the technical challenges to be considered at the moment of investing inM2M solutions for developing countries.

  • 184.
    Miao, Guowang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Azari, Amin
    KTH, School of Information and Communication Technology (ICT).
    Hwang, Taewon
    E2-MAC: Energy Efficient Medium Access for Massive M2M Communications2016In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 64, no 11, p. 4720-4735Article in journal (Refereed)
    Abstract [en]

    In this paper, we investigate energy-efficient clustering and medium access control (MAC) for cellular-based M2M networks to minimize device energy consumption and prolong network battery lifetime. First, we present an accurate energy consumption model that considers both static and dynamic energy consumptions, and utilize this model to derive the network lifetime. Second, we find the cluster size to maximize the network lifetime and develop an energy-efficient cluster-head selection scheme.

    Furthermore, we find feasible regions where clustering is beneficial in enhancing network lifetime. We further investigate communications protocols for both intra- and inter-cluster communications. While inter-cluster communications use conventional cellular access schemes, we develop an energy-efficient and load-adaptive multiple access scheme, called n-phase CSMA/CA, which provides a tunable tradeoff between energy efficiency, delay, and spectral efficiency of the network. The simulation results show that the proposed clustering, cluster-head selection, and communications protocol design outperform the others in energy saving and significantly prolong the lifetimes of both individual nodes and the whole M2M network.

  • 185.
    Miao, Guowang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Himayat, Nageen
    Talwar, Shilpa
    Probabilistic interference mitigation for wireless cellular networks2007Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    An interference mitigation system randomizes transmissions to cell-edge users by carefully controlling the probability of transmission to these users, thereby creating a virtual fractional frequency system that does not require extensive frequency management and coordination across the network. In some embodiments, the interference mitigation system identifies severely interfered links and reduces the probability of transmission on these links, with the result being a reduced probability of interference.

  • 186.
    Miao, Guowang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Västberg, Anders
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Energy Efficiency in the Wideband Regime2013In: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 12, no 8, p. 4102-4109Article in journal (Refereed)
    Abstract [en]

    End-to-end communication is the fundamental building block of communication networks. In this paper, we discuss globally optimal energy efficient design for end-to-end communications. An end-to-end multiple-hop system with one sender, one receiver, and multiple relays is considered. We first study in detail energy-efficient designs in the wideband regime that is characterized by wide signal bandwidth and low spectral efficiency, and later briefly those in the narrowband regime. We will reveal the globally optimal link adaptation as well as relay deployment strategies such that the whole system can achieve the highest energy efficiency. The technologies proposed can be used in various communication systems, such as the deployment and communication of wired core networks and wireless relay networks, to improve their energy efficiency. While this paper focuses on a linear end-to-end network topology, the methodology can be easily extended to two-dimensional network topologies for energy-efficient designs of the whole network

  • 187.
    Miao, Guowang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Zhang, J.
    Apparatus and method for channel measurement in radio link monitoring in a wireless network2010Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    A subscriber station is configured to perform a channel measurement on a communication channel in restricted sub-frames for DRX and NON-DRX modes. The subscriber station includes a receiver configured to receive signals from a base station. The subscriber station also includes processing circuitry. When the receiver receives higher layer signaling indicating that channel quality measurement is to be performed in restricted sub-frames for measurement (RFSM), the processing circuitry is configured to extend an evaluation period for monitoring a quality of the communication channel.

  • 188.
    Mitthalal, Dipesh Dugar
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Social Proximity Indicator Application Enhancing Personalization for the User: A User Centric Multimodal Smartphone based Social Proximity Indicator2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The smartphone has become an important part of our daily life. It takes advantage of multiple built-in sensors, along with internet connectivity, to provide a variety of services including navigation, weather forecasts, media capturing/sharing, and many more. The smartphone has become a hub for our social interactions, ranging from traditional voice communications through messaging, to online social networking.

    There are endless possibilities for a new generation of applications that automatically adapts according to users’ social affinities. The key enabler is to understand the social profile of the user and to realize a Social Proximity Indicator (SPI). This indicator of a user’s social profile includes the user’s location, preferences, common friends, frequent interactions among friends, community membership, and many more attributes. This project addresses the exploitation of the user’s smartphone as a detector of these user’s social contexts in order to infer the social proximity between any 2 (or more) people. The goal of this social proximity indicator is to identify the (current) set of smartphone users that would want to participate in an application specific activity, such as media sharing, group conversation, etc. SPI identifies users based on their social interactions and common preferences.

    Based on this SPI, a photo sharing application is proposed and built for the Android smartphone platform. This application uses multiple physical and virtual sensors (hosted by the user’s smartphone) to determine the context of the user. After inferring this context, the application initiates photo sharing among an identified group sharing this context. The application, as well as the underlying code, theoretical concepts, and results are presented in this thesis. The experiments conducted during this thesis project indicate that it is feasible to build smartphone based social proximity based applications in which proximity incorporates much more than simply physical location, thus going beyond existing applications.

  • 189.
    Mobeen, Shariq
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    A Topologically Aware Resource Management System2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As companies fight for market share whoever is able to bring products to market faster has an advantage over their competitors. Therefore it is absolutely essential to constantly evaluate and optimize processes to achieve shorter time-to-market for products.

    These optimizations have to be carried out in all parts of a company. This thesis describes one such attempt made by a Swedish telecommunication vendor focused on enabling a resource management system to gain a greater understanding of the resources available during testing. This system manages all of the hardware utilized by the users, software testers, within one particular part of the organization and aids users by automatically converting the information stored in its database into a configuration file that will later be used in the testing framework’s execution environment. Unfortunately, the current version of this resource management system lacks semantic understanding of the information necessary to automatically generate the configuration file, leaving a rather large part of the configuration file to be manually entered by the testers, a rather time-consuming task. The inability to completely automate the process means that the testing process is slower, more error prone, and increases the work needed for a new engineer to become a productive software tester.

    In order for the resource management system to automatically generate the configuration file it needs to know not only which resources it is managing, but must also how these resources are interconnected, i.e. the topology of the resources. For this reason this thesis describes how to make the resource management system topologically aware, thus making verification of the System under Test (SUT) more efficient and mitigating the problems mentioned above. This thesis does not deal with the intricate details of how to automatically extract the topology, as this is inherently domain specific and thus difficult to generalize. Rather, this thesis focused on how to allow users to custom-build their desired topology by defining a set of rules that restrict how resources can be interconnected.

    The goal of providing functionality for storing and retrieving topological information from database has been successfully achieved, and the resulting code has been integrated into the existing resource management system. However, the functionality has not yet been delivered because of a limitation in our front controller that stops us from providing an efficient web interface to our tool. After delivery the implemented solution is expected to remove most manual work related to test configuration and therefore also reduce the learning curve for new engineers.

  • 190.
    Monti, Paolo
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Costa, J. C. W. A.
    Farias, F. S.
    Fiorani, M.
    Nilson, Mats
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Tombaz, Sibel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Västberg, Anders
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Green mobile backhaul in heterogeneous wireless deployments2013In: Asia Communications and Photonics Conference, ACP 2013, Optical Society of America, 2013Conference paper (Refereed)
    Abstract [en]

    This tutorial first introduces and describes different backhaul technological and architectural options (i.e., fiber-, microwave-, and copper-based), then it discusses their impact on the energy consumption of current and future heterogeneous mobile wireless access deployments.

  • 191.
    Montojo Villasanta, Javier
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Maqueda Viñas, Manuel
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Congestion Identification in a Radio Access Transport Network2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The convergence of mobile services and Internet has brought a radical change in mobile networks. An all IP network architecture, an evolution of the radio access transport network, is required to support new high-bandwidth services. Unfortunately, existing control mechanisms are insufficient to guarantee end users a high quality of experience. However, coordinating radio and transport network resources is expected to yield a more efficient solution.

    This thesis project investigates the interactions between the congestion avoidance protocols, explicit congestion notification, and the traffic engineering metrics for latency and bandwidth, when using Open Shortest Path First with traffic engineering (OSPF-TE) as a routing protocol. Using knowledge of these interactions, it is possible to identify the appearance of bottlenecks and to control the congestion in the transport links within a radio access transport network.

    Augmenting a topology map with the network’s current characteristics and reacting to evidence of potential congestion, further actions, such as handovers can be taken to ensure the users experience their expected quality of experience. The proposed method has been validated in a test bed. The results obtained from experiments and measurements in this test bed provide a clear picture of how the traffic flows in the network. Furthermore, the behavior of the network observed in these experiments, in terms of real-time performance and statistical analysis of metrics over a period of time, shows the efficiency of this proposed solution.

  • 192.
    Moradinia, Pourya
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Sakhi, Imal
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Mobile Opportunistic Services for Experience Sharing: Via a NetInf Android Application2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Information-Centric Networking (ICN) is a new research area concerning creating a new network architecture that would be more suitable for both current and the future's network. The MOSES (Mobile Opportunistic Services for Experience Sharing) project is part of this development. The project works with the development and demonstration of the Network of Information (NetInf) protocol, which is an implementation of the ICN concept.

    This Master’s thesis project is part of the MOSES project and aims to assist the MOSES project with the demonstration of a mobile opportunistic sharing concept based on the NetInf protocol. Demonstrating the MOSES concept in practice requires deep understanding of networking, localization, transport, and dissemination of digital content in an ad hoc network. This implementation requires an analysis of the previous work, development of new functionalities, and finally an analysis of a series of controlled experiments.

    This Master’s thesis project has designed, implemented, and evaluated an Android application within the MOSES framework by using the previously developed NetInf Android library. This prototype is used to demonstrate how mobile Android users can opportunistically share and disseminate content based on their location using the MOSES/ICN concept. The functionality and efficiency of the prototype Android application built during this thesis project has been analyzed and evaluated by conducting a series of controlled experiments under the supervision of MOSES researchers. The results of these controlled experiments has provided insight for MOSES researchers as well as explored the concept of using ICN (NetInf) for opportunistic content distribution. The experiment results aim at assisting MOSES researchers to extend and further develop the prototype application and the involved algorithms to create a fully functional mobile application for experience sharing services tailored to large-scale events.

  • 193. Muhammad, Ajmal
    et al.
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Wosinska, Lena
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Forchheimer, Robert
    Service Differentiated Provisioning in Dynamic WDM Networks Based on Set-Up Delay Tolerance2013In: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 5, no 11, p. 1250-1261Article in journal (Refereed)
    Abstract [en]

    Optical networks are expected to provide a unified platform for a diverse set of emerging applications (three-dimensional TV, digital cinema, e-health, grid computing, etc). The service differentiation will be an essential feature of these networks. Considering the fact that users have different levels of patience for different network applications, referred to as set-up delay tolerance, it will be one of the key parameters for service differentiation. Service differentiation based on set-up delay tolerance will not only enable network users to select an appropriate service class (SC) in compliance with their requirements, but will also provide an opportunity to optimize the network resource provisioning by exploiting this information, resulting in an improvement in the overall performance. Improvement in network performance can be further enhanced by exploiting the connection holding-time awareness. However, when multiple classes of service with different set-up delay tolerances are competing for network resources, the connection requests belonging to SCs with higher set-up delay tolerance have better chances to grab the resources and leave less room for the others, resulting in degradation in the blocking performance of less patient customers. This study proposes different scheduling strategies for promoting the requests belonging to smaller set-up delay tolerance SCs, such as giving priority, reserving some fraction of available resources, and augmenting the research space by providing some extra paths. Extensive simulation results show that 1) priority in the rescheduling queue is not always sufficient for eradicating the degradation effect of high delay tolerant SCs on the provisioning rate of the most stringent SC, and 2) by utilizing the proposed strategies, resource efficiency and overall network blocking performance improve significantly in all SCs.

  • 194.
    Mukhammadov, Ruslan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    A scalable database for a remote patient monitoring system2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today one of the fast growing social services is the ability for doctors to monitor patients in their residences. The proposed highly scalable database system is designed to support a Remote Patient Monitoring system (RPMS). In an RPMS, a wide range of applications are enabled by collecting health related measurement results from a number of medical devices in the patient’s home, parsing and formatting these results, and transmitting them from the patient’s home to specific data stores. Subsequently, another set of applications will communicate with these data stores to provide clinicians with the ability to observe, examine, and analyze these health related measurements in (near) real-time. Because of the rapid expansion in the number of patients utilizing RPMS, it is becoming a challenge to store, manage, and process the very large number of health related measurements that are being collected. The primary reason for this problem is that most RPMSs are built on top of traditional relational databases, which are inefficient when dealing with this very large amount of data (often called “big data”).

    This thesis project analyzes scalable data management to support RPMSs, introduces a new set of open-source technologies that efficiently store and manage any amount of data which might be used in conjunction with such a scalable RPMS based upon HBase, implements these technologies, and as a proof of concept, compares the prototype data management system with the performance of a traditional relational database (specifically MySQL). This comparison considers both a single node and a multi node cluster. The comparison evaluates several critical parameters, including performance, scalability, and load balancing (in the case of multiple nodes). The amount of data used for testing input/output (read/write) and data statistics performance is 1, 10, 50, 100, and 250 GB.

    The thesis presents several ways of dealing with large amounts of data and develops & evaluates a highly scalable database that could be used with a RPMS. Several software suites were used to compare both relational and non-relational systems and these results are used to evaluate the performance of the prototype of the proposed RPMS. The results of benchmarking show that MySQL is better than HBase in terms of read performance, while HBase is better in terms of write performance. Which of these types of databases should be used to implement a RPMS is a function of the expected ratio of reads and writes. Learning this ratio should be the subject of a future thesis project.

  • 195. Mölleryd, Bengt G.
    et al.
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Analysis of spectrum auctions in India An application of the opportunity cost approach to explain large variations in spectrum prices2014In: Telecommunications Policy, ISSN 0308-5961, E-ISSN 1879-3258, Vol. 38, no 3, p. 236-247Article in journal (Refereed)
    Abstract [en]

    The remarkable growth of mobile communication has reinforced the significance of the radio spectrum for mobile network operators. The availability of spectrum varies considerably between different countries due to national regulatory decisions. The focus in this paper is on India where operators have access to a limited amount of spectrum. This paper analyses the value of spectrum by estimating the opportunity cost, which is calculated by the savings that can be achieved by acquiring appropriate amount of spectrum rather than investing in additional base stations. The applied approach combines network deployment, user demand levels, cost, and capacity issues, which are integrated in the application in the opportunity cost approach for spectrum. The opportunity cost of spectrum is compared with prices paid at spectrum auctions. The analysis includes a discussion of drivers that determine the willingness to pay for spectrum. The results show that the opportunity cost of spectrum in relation to auction prices is lower than prices operators paid for 3G spectrum in the metro circles (service areas) while the value derived from the opportunity cost is higher than auction prices in the remaining circles.

  • 196.
    Ndikuriyo, Laurier
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Addressing non-conformities in a ERTMS implementation: Collecting non-conformities in ERTMS simulation and analyzing their management via a database2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The European Rail Traffic Management System (ERTMS) aims to standardize train control command and communication systems in Europe. The main goal of its introduction is to develop trans-European railway traffic and increase competition. The two main components of ERTMS are European Train Control System (ETCS), which is an Automatic Protection System (ATP), and GSM–Railway (GSM-R).GSM-R is a radio transmission system that provides data and voice communication between the train and trackside facilities. Classical rail signaling systems are recommended to be updated to meet these standards.

    This master’s thesis is conducted in cooperation with Bombardier Transportation (BT), the rail equipment division of firm Bombardier Inc. It explores a part of ERTMS implementation and aims to identify its failures/non-conformities during its simulation. A non-conformity is any deviation or nonfulfillment of a requirement involving a product manufactured at BT. This thesis first collects failures/non conformities in test sessions and stores it into databases. A failure/non-conformity is processed by many engineers from the time it is detected in a test until it is resolved.  This thesis project seeks to investigate the exchange and the management of failures in both the tools and databases, together with analyzing the interaction between engineers through tools and databases. Non conformities detected during the simulation is stored in databases. The goal is to utilize this data to highlight parts of ERTMS implementation which generate most of non-conformities during the simulation. This information indicates to engineers where to focus and act in order to improve Bombardier Transportation’s products.

    This thesis successfully simulated a part of ERMS implementation. Several different tests cases were conducted and seven non-conformities were detected. These non-conformities were used to investigate and analyze the process of managing failures in tools and databases. This thesis proved that the exchange and the management of information about non-conformities was inefficient and time consuming. In the worst case, non-conformities were completely lost during this process. Several corrective actions were proposed in order to improve the handling of non-conformities.

  • 197.
    Ning, Xufei
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Push-based low-latency solution for Tracked Resource Set protocol: An extension of Open Services for Lifecycle Collaboration specification2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Currently, the development of embedded system requires a variety of software and tools. Moreover, most of this software and tools are standalone applications, thus they are unconnected and their data can be inconsistent and duplicated. This increase both heterogeneity and the complexity of the development environment.

    To address this situation, tool integration solutions based on Linked Data are used, as they provide scalable and sustainable integration across different engineering tools. Different systems can access and share data by following the Linked-Data-based Open Service for Lifecycle Collaboration (OSLC) specification. OSLC uses the Tracked Resource Set (TRS) protocol to enable a server to expose a resource set and to enable a client to discover a resource in the resource set.

    Currently, the TRS protocol uses a client pull for the client to update its data and to synchronize with the server. However, this method is inefficient and time consuming. Moreover, high-frequency pulling may introduce an extra burden on the network and server, while low-frequency pulling increases the system’s latency (as seen by the client).

    A push-based low-latency solution for the TRS protocol was implemented using Message Queue Telemetry Transport (MQTT) technology. The TRS server uses MQTT to push the update patch (called a ChangeEvent) to the TRS client, then the client updates its content according to this ChangeEvent. As a result, the TRS client synchronizes with the TRS server in real time.

    Furthermore, a TRS adaptor was developed for Atlassian’s JIRA, a widely-used project and issue management tool. This JIRA-TRS adaptor provides a TRS provider with the ability to share data via JIRA with other software or tools which utilize the TRS protocol.

    In addition, a simulator was developed to simulate the operations in JIRA for a period of time (specifically the create, modify, and delete actions regarding issues) and acts as a validator to check if the data in TRS client matches the data in JIRA.

    An evaluation of the push-based TRS system shows an average synchronization delay of around 30 milliseconds. This is a huge change compared with original TRS system that synchronized every 60 seconds.

  • 198.
    Nordlund, Fredrik Hans
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Enabling Network-Aware Cloud Networked Robots with Robot Operating System: A machine learning-based approach2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During the recent years, a new area called Cloud Networked Robotics (CNR) has evolved from conventional robotics, thanks to the increasing availability of cheap robot systems and steady improvements in the area of cloud computing. Cloud networked robots refers to robots with the ability to offload computation heavy modules to a cloud, in order to make use of storage, scalable computation power, and other functionalities enabled by a cloud such as shared knowledge between robots on a global level. However, these cloud robots face a problem with reachability and QoS of crucial modules that are offloaded to the cloud, when operating in unstable network environments. Under such conditions, the robots might lose the connection to the cloud at any moment; in worst case, leaving the robots “brain-dead”.

    This thesis project proposes a machine learning-based network aware framework for a cloud robot, that can choose the most efficient module placement based on location, task, and the network condition. The proposed solution was implemented upon a cloud robot prototype based on the TurtleBot 2 robot development kit, running Robot Operating System (ROS). A continuous experiment was conducted where the cloud robot was ordered to execute a simple task in the laboratory corridor under various network conditions. The proposed solution was evaluated by comparing the results from the continuous experiment with measurements taken from the same robot, with all modules placed locally, doing the same task.

    The results show that the proposed framework can potentially decrease the battery consumption by 10% while improving the efficiency of the task by 2.4 seconds (2.8%). However, there is an inherent bottleneck in the proposed solution where each new robot would need 2 months to accumulate enough data for the training set, in order to show good performance. The proposed solution can potentially benefit the area of CNR if connected and integrated with a shared-knowledge platform which can enable new robots to skip the training phase, by downloading the existing knowledge from the cloud.

  • 199.
    Noz, Marilyn E.
    et al.
    New York University, Department of Radiology.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    F-18-FDG PET in detecting primary breast cancer: Reply2007In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 48, no 10, p. 1752-1752Article in journal (Other academic)
  • 200.
    Obregon, Evanny
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    On the Deployment of Large-Scale High-Capacity Wireless Systems with Secondary Spectrum Access2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The avalanche in mobile data consumption represents a big challenge for mobile networks operators and national regulators. This thesis focuses on finding additional spectrum to meet this demand in a cost-efficient way by considering shared spectrum access. Our studies aim at identifying key factors in achieving large-scale business success,quantifying the spectrum availability and identifying suitable regulatory/sharing polices for large-scale secondary access in the aeronautical and radar bands. This thesis proposes a research methodology, that considers business, technical and regulatory aspects involved in assessing commercial viability of large-scale deployment of wireless networks, employing vertical spectrum sharing in the aeronautical and radar bands. We pinpoint the following criteria which are critical in ensuring business success:spectrum availability, radio technology availability, low-cost end-userdevices, system scalability and quality of service. Our investigation centers on the technical aspects of these criteria, and thus deals mainly with the assessment of spectrum availability. The availability of spectrum opportunities is found to be ample for adjacent channel usage despite the strict requirements of the radar receiver. However, it is alsovery location-dependent and mostly non-contiguous.Finally, with regard to the regulatory aspects, our results show thatapplying regulatory policies, especially to the deployment of secondary users, can boost availability in cities or urban areas where the capacity demand is high. In addition, Licensed Shared Access (LSA) is identified as a suitable regulatory framework to meet tough protection criteria ofthe radar receivers and to apply the selected regulatory policies to improve exploitation of sharing opportunities. Based on our results and analysis, we conclude that there is a significant amount of spectrum opportunities for large-scale secondary access in the aeronautical and radar bands from the technical point of view. However, the commercial viability of secondary spectrum access is still undetermined giventhe remaining uncertainties regarding its total cost and the exact time needed for relevant technology to become available. Moreover, thereis no single answer to the commercial viability since it will most likelydepend on the country or region in question, which affects the spectrum availability, which in turn is a key criterion for business success. Futurework should therefore strive to clarify these uncertainties and to identify new responsibilities for all the entities involved in the LSA framework. Moreover, a quantitative evaluation would be needed to obtain more explicit conclusions on the business viability.

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