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  • 1.
    Apanasevic, Tatjana
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Arvidsson, Niklas
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Sustainability and Industrial Dynamics.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Mobile payments: a proposal for a context-oriented approach based on socio-technical system theoryIn: Journal of Innovation Management, ISSN 2183-0606Article in journal (Refereed)
    Abstract [en]

    A recent review on mobile payment research by Dahlberg et al. (2015) concludes that there is a need to synthesise this research area by studying contexts in which innovation is done as well as to integrate different aspects of research. This article aims to provide a proposal for how to achieve such integration and context-orientation by building on previous studies as well as an additional review. Our systematic literature review of mobile payments research is focused on papers published during 2006–2016. The main objective is to examine how mobile payments research has been conducted from the methodological and theoretical perspectives. Our findings show that research on mobile payments is a multidisciplinary research. Three main themes, which are in line with previous studies, in research are: customer adoption, technological aspects, and business aspects. Moreover, research is mainly analytical based on deductive approach. To meet the challenge formulated in the previous research, we propose and apply a socio-technical system framework to achieve synthesis and context-specific consideration in future research on mobile payments.

  • 2.
    Apanasevic, Tatjana
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Mobile ticketing services in the Northern Europe: Critical business model issues2018In: Internet of Things Business Models, Users, and Networks, 2017 / [ed] Morten Falch, Copenhagen, Denmark: IEEE, 2018, p. 1-8Conference paper (Refereed)
    Abstract [en]

    Started as SMS ticketing, today, mobile ticketing services become a platform for combined mobility solutions that integrate mobile ticketing, bike renting, car sharing, and parking payment services. Mobile ticketing services provide a number of benefits for public transport companies and passengers, however, in some Northern European countries, the share of mobile ticket sales does not exceed 10 percent. In this paper, we analyse business models of three types of mobile ticketing services (SMS, in-app, and “Be-In Be-Out” (BIBO)) in order to identify factors that negatively affect wider penetration of mobile ticketing. In order to do so, we use STOF (Service, Technology, Organisation, and Finance) model. The research reveals that there are a number of challenges related to service, technology, and finance domains of mobile ticketing. Due to this, with the help of price policy, many public transport companies push choices of their customers towards use of plastic travel card.

  • 3.
    Apanasevic, Tatjana
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Mobile ticketing services in the Northern Europe Critical business model issues2017In: 2017 JOINT 13TH CTTE AND 10TH CMI CONFERENCE ON INTERNET OF THINGS - BUSINESS MODELS, USERS, AND NETWORKS / [ed] Falch, M, IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    Started as SMS ticketing, today, mobile ticketing services become a platform for combined mobility solutions that integrate mobile ticketing, bike renting, car sharing, and parking payment services. Mobile ticketing services provide a number of benefits for public transport companies and passengers, however, in some Northern European countries, the share of mobile ticket sales does not exceed 10 percent. In this paper, we analyse business models of three types of mobile ticketing services (SMS, in-app, and "Be-InBe-Out" (BIBO)) in order to identify factors that negatively affect wider penetration of mobile ticketing. In order to do so, we use STOF (Service, Technology, Organisation, and Finance) model. The research reveals that there are a number of challenges related to service, technology, and finance domains of mobile ticketing. Due to this, with the help of price policy, many public transport companies push choices of their customers towards use of plastic travel card.

  • 4.
    Apanasevic, Tatjana
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    The value of mobile ticketing from a public transport perspective2018In: Journal of Payments Strategy & Systems, Vol. 11, no 4, p. 292-305Article in journal (Refereed)
    Abstract [en]

    Within the field of mobile payments, the market segment for mobile ticketing services is expected to grow, driven by the public transport sector. Although a large number of studies have explored the value of mobile payments to customers (ie service end users), there is a lack of research exploring the value of mobile payment and mobile ticketing for business customers (ie transport companies and retailers). This paper aims to address this gap and to explore the kinds of value that mobile ticketing services create for public transport companies. The research considers mobile ticketing services in six Northern European countries. The research findings suggest that within the business-to-business context, mobile ticketing services create multiple dimensions of value, namely enhanced technical functionality; financial value; better working environment; operational value; and reputational and customer relationship value. For passengers, meanwhile, value takes the form of convenience and service enhancement. These benefits are factors driving adoption of mobile ticketing and mobile payment services by public transport companies.

  • 5.
    Azari, Amin
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Bitcoin Price Prediction: An ARIMA ApproachManuscript (preprint) (Other academic)
    Abstract [en]

    Bitcoin is considered as the most valuable currency in the world. Besides being highly valuable, its value has also experienced a steep increase, from around 1 dollar in 2010 to around 18000 in 2017. Then, in recent years, it has attracted considerable attention in a diverse set of fields, including economics and computer science. The former mainly focuses on studying how it affects the market, determining reasons behinds its price fluctuations, and predicting its future prices. The latter mainly focuses on its vulnerabilities, scalability, and other techno-cryptoeconomic issues. Here, we aim at revealing the usefulness of traditional autoregressive integrative moving average (ARIMA)model in predicting the future value of bitcoin by analyzing the price time series in a 3-years-long time period. On the one hand, our empirical studies reveal that this simple scheme is efficient in sub-periods in which the behavior of the time-series is almost unchanged, especially when it is used for short-term prediction,e.g. 1-day. On the other hand, when we try to train the Arima model to a 3-years-long period, during which the bitcoin price has experienced different behaviors, or when we try to use it for a long-term prediction, we observe that it introduces large prediction errors. Especially, the ARIMA model is unable to capture the sharp fluctuations in the price, e.g. the volatility at the end of 2017. Then, it calls for more features to be extracted and used along with the price for a more accurate prediction of the price. We have further investigated the bitcoin price prediction using an ARIMA model trained over the whole dataset, as well as a limited part of the history of the bitcoin price, with length of w, as inputs. Our study sheds lights on the interaction of the prediction accuracy, choice of (p; q; d), and window size w.

  • 6.
    Azari, Amin
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    On the DoF and Secure DoF of K-User MIMO Interference Channel with Instantaneous Relays2019Manuscript (preprint) (Other academic)
    Abstract [en]

    Interference channel, in which multiple user pairs communicate over shared resources, is a building block of communications networks. Here, the K-user interference channel (IC) aided by J instantaneous relays (IRs), i.e. relays without delay, is considered. For KICJR networks, where K>2 and J>1, the DoF performance and achievable schemes have not been investigated in literature. Here, we devise a novel achievable scheme, called restricted interference alignment (RIA), which restricts the received interference from each source at each destination in a limited sub-space, and then, aligns the restricted interferences. Furthermore, we develop an analytical tool for finding a tight upper bound on DoF of KICJR networks by analyzing the properness of the interference alignment equations. Moreover, we develop linear beamforming design for sources and relays based on the mean square error (MSE) minimization, as an achievable scheme. The performance evaluation results show that the achievable sum DoF by using the proposed RIA scheme and the MSE-based beamforming design match well with the derived upper bounds. Furthermore, the results confirm that the achieved sum DoF using the RIA scheme outperforms the existing achievable schemes. Motivated by these promising results, we further investigate impact of IRs in providing physical layer security, i.e. achieving secure DoF in interference networks. Specifically, we derive a lower bound on the achievable secure DoF by devising an achievable scheme, called transmission in the null space (TNS). This scheme makes the cross channels rank deficient and enables sources to select their transmit filters in the constructed null spaces. Performance evaluation shows that by leveraging IRs, the secure DoF performance of interference networks could be increased significantly. The proposed analytical framework in this work for rank deficiency-powered DoF analysis is expected to also attract attention from other research areas, e.g. beamforming design for millimeter wave communications.

  • 7.
    Azari, Amin
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Serving IoT Communications over Cellular Networks: Challenges and Solutions in Radio Resource Management for Massive and Critical IoT Communications2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Internet of Things (IoT) communications refer to the interconnections of smart devices, with reduced human intervention, which enable them to participate more actively in everyday life. It is expected that introduction of a scalable, energy efficient, and reliable IoT connectivity solution can bring enormous benefits to the society, especially in healthcare, wellbeing, and smart homes and industries. In the last two decades, there have been efforts in academia and industry to enable IoT connectivity over the legacy communications infrastructure. In recent years, it is becoming more and more clear that the characteristics and requirements of the IoT traffic are way different from the legacy traffic originating from existing communications services like voice and web surfing, and hence, IoT-specific communications systems and protocols have received profound attention. Until now, several revolutionary solutions, including cellular narrowband-IoT, SigFox, and LoRaWAN, have been proposed/implemented. As each of these solutions focuses on a subset of performance indicators at the cost of sacrificing the others, there is still lack of a dominant player in the market capable of delivering scalable, energy efficient, and reliable IoT connectivity. The present work is devoted to characterizing state-of-the-art technologies for enabling large-scale IoT connectivity, their limitations, and our contributions in performance assessment and enhancement for them. Especially, we focus on grant-free radio access and investigate its applications in supporting massive and critical IoT communications. The main contributions presented in this work include (a) developing an analytical framework for energy/latency/reliability assessment of IoT communications over grant-based and grant-free systems; (b) developing advanced RRM techniques for energy and spectrum efficient serving of massive and critical IoT communications, respectively; and (c) developing advanced data transmission/reception protocols for grant-free IoT networks. The performance evaluation results indicate that supporting IoT devices with stringent energy/delay constraints over limited radio resources calls for aggressive technologies breaking the barrier of the legacy interference-free orthogonal communications.

  • 8.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Bria, Aurelian
    System and method for providing communication rules based on a status associated with a battery of a device2017Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The disclosure relates to communication systems and, more particularly, to a system and method for providing communication rules based on a status associated with a battery of a device.

  • 9.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Performance Evaluation and Optimization of LPWA IoT Networks: A Stochastic Geometry Approach2018In: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings, IEEE, 2018, article id 8647881Conference paper (Refereed)
    Abstract [en]

    Leveraging grant-free radio access for enabling low-power wide-area (LPWA) Internet of Things (IoT) connectivity has attracted lots of attention in recent years. Regarding lack of research on LPWA IoT networks, this work is devoted to reliability modeling, battery-lifetime analysis, and operation-control of such networks. We derive the interplay amongst density of the access points, communication bandwidth, volume of traffic from heterogeneous sources, and quality of service (QoS) in communications. The presented analytical framework comprises modeling of interference from heterogeneous sources with correlated deployment locations and time-frequency asynchronous radio-resource usage patterns. The derived expressions represent the operation regions and rates in which, energy and cost resources of devices and the access network, respectively, could be traded to achieve a given level of QoS in communications. For example, our expressions indicate the expected increase in QoS by increasing number of transmitted replicas, transmit power, density of the access points, and communication bandwidth. Our results further shed light on scalability of such networks and figure out the bounds up to which, scaling resources can compensate the increase in traffic volume and QoS demand. Finally, we present an energy-optimized operation control policy for IoT devices. The simulation results confirm tightness of the derived analytical expressions, and indicate usefulness of them in planning and operation control of IoT networks.

  • 10.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Self-organized Low-power IoT Networks: A Distributed Learning Approach2018In: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018Conference paper (Refereed)
    Abstract [en]

    Enabling large-scale energy-efficient Internet-ofthings (IoT) connectivity is an essential step towards realization of networked society. While legacy wide-area wireless systems are highly dependent on network-side coordination, the level of consumed energy in signaling, as well as the expected increase in the number of IoT devices, makes such centralized approaches infeasible in future. Here, we address this problem by self-coordination for IoT networks through learning from past communications. To this end, we first study low-complexity distributed learning approaches applicable in IoT communications. Then, we present a learning solution to adapt communication parameters of devices to the environment for maximizing energy efficiency and reliability in data transmissions. Furthermore, leveraging tools from stochastic geometry, we evaluate the performance of proposed distributed learning solution against the centralized coordination. Finally, we analyze the interplay amongst energy efficiency, reliability of communications against noise and interference over data channel, and reliability against adversarial interference over data and feedback channels. The simulation results indicate that compared to the state of the art approaches, both energy efficiency and reliability in IoT communications could be significantly improved using the proposed learning approach. These promising results, which are achieved using lightweight learning, make our solution favorable in many low-cost low-power IoT applications.

  • 11.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Ozger, Mustafa
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Serving Non-Scheduled URLLC Traffic: Challenges and Learning-Powered StrategiesManuscript (preprint) (Other academic)
    Abstract [en]

    Supporting ultra-reliable low-latency communications (URLLC) is a major challenge of 5G wireless networks. Whilst enabling URLLC is essential for realizing many promising 5G applications, the design of communications' solutions for serving such unseen type of traffic with stringent delay and reliability requirements is in its infancy. In prior studies, physical and MAC layer solutions for assuring the end-to-end delay requirement of scheduled URLLC traffic have been investigated. However, there is lack of study on enabling non-scheduled transmission of urgent URLLC traffic, especially in coexistence with the scheduled URLLC traffic. This study at first sheds light into the coexistence design challenges, especially the radio resource management (RRM) problem. It also leverages recent advances in machine learning (ML) to exploit spatial/temporal correlation in user behaviors and use of radio  resources, and proposes a distributed risk-aware ML solution for RRM. The proposed solution benefits from hybrid orthogonal/non-orthogonal radio resource slicing, and proactively regulates the spectrum needed for satisfying delay/reliability requirement of each traffic type. A case study is introduced to investigate the potential of the proposed RRM in serving coexisting URLLC traffic types. The results further provide insights on the interplay between the reliabilities of coexisting traffic, uncertainties in users' demands and channel conditions, and amount of required radio resources.

  • 12.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Masoudi, Meysam
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Optimized Resource Provisioning and Operation Control for Low-power Wide-area IoT NetworksManuscript (preprint) (Other academic)
    Abstract [en]

    Grant-free radio access is a promising solution for reducing energy consumption and access delay in low power wide-area (LPWA) Internet of Things (IoT) networks. This work is devoted to reliability modeling, battery-lifetime analysis, resource provisioning, and operation control for grantfreeIoT networks. Our modeling captures correlation in devices’locations, benefits from 3D (time/frequency/code) interference analysis, and enables coexistence analysis of multi-type IoT technologies. We derive the interplay amongst density of the access points, communication bandwidth, traffic volume, and quality of service (QoS) of communications. Deriving the interplay enables scalability analysis, i.e. it figures out the required increase in device's energy consumption (or access network’s resources) for compensating the increase in traffic volume or QoS demand. Our major contribution consists in deriving traffic loads and respective exchange rates in which, energy and cost resources of devices and the access network, respectively, could be traded to achieve a given level of QoS. We further indicate operation regions in which scaling a parameter turns from being a friend into a foe. Finally, we present energy- and cost-optimized operation control and resource provisioning strategies, respectively. The simulation results confirm tightness of the analytical expressions, and indicate the usefulness of them in planning and operation control of IoT networks.

  • 13.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Stefanovic, Cedomir
    Aalborg University.
    Popovski, Petar
    Aalborg University.
    Latency-Energy Tradeoff based on Channel Scheduling and Repetitions in NB-IoT Systems2018In: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018, article id 8648024Conference paper (Refereed)
    Abstract [en]

    Narrowband Internet of Things (NB-IoT) is the latest IoT connectivity solution presented by the 3rd generation partnership project (3GPP). NB-IoT introduces coverage classes and offers a significant link budget improvement by allowing repeated transmissions by nodes that experience high path loss. However, those repetitions necessarily increase the energy consumption and the latency in the whole NB-IoT system. The extent to which the whole system is affected depends on the scheduling of the uplink and downlink channels. We address this question, not treated previously, by developing a tractable model of NB-IoT access protocol operation, comprising message exchanges in random-access, control, and data channels, both in the uplink and downlink The model is then used to analyze the impact of channel scheduling as well as the interaction of coexisting coverage classes, through derivation of the expected latency and battery lifetime for each coverage class. These results are subsequently employed in investigation of latency-energy tradeoff in NB-IoT channel scheduling as well as determining the optimized operation points. Simulations results show validity of the analysis and confirm that channel scheduling and coexistence of coverage classes significantly affect latency and battery lifetime performance of NB-IoT devices.

  • 14.
    Azari, Amin
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Popovski, Petar
    Stefanovic, Cedomir
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Grant-Free Radio Access for Cellular IoTManuscript (preprint) (Other academic)
    Abstract [en]

    Radio resource management (RRM) is a major factor affecting the delay, reliability, and energy consumption of Internet of Things (IoT) communications. This article is focused on grant-free access, a class of techniques suited to support massive IoT connectivity. Within the proposed scheme, the IoT devices transmit multiple replicas of the same packet. In addition to that, the receiver makes use of the random timing and frequency offsets in order to carry out Successive Interference Cancellation (SIC). The system performance is investigated by using a model based on stochastic geometry, leading to closed-form expressions for the key performance indicators, such as reliability and battery lifetime. The framework allows optimization of the number of replicas per device. This results in overall improvement of the energy consumption, delay and reliability, at the expense of more complex processing at the Base Station. The evaluation results indicate that the proposed data transmission and reception schemes can significantly prolong battery lifetime of IoT devices by removing the need for connection establishment and reducing the number of retransmissions. The obtained results also indicate existence of traffic-load regions, where grant-free radio access outperforms the grant-based one, which is used in LTE and NB-IoT systems. These results pave the way for enabling intelligent grant-based/free operation mode switching in 5G networks.

  • 15.
    Bai, Chumeng
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Evaluation and Improvement of Decentralized Congestion Control for Multiplatooning Application2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Platooning has the potential to be a breakthrough in increasing road capacity and reducing fuel consumption, as it allows a chain of vehicles to closely follow each other on the road. When the number of vehicles increases, platoons will follow one another in what is referred to as multiplatooning. Many Cooperative Intelligent Transportation Systems (C-ITS) applications rely on periodically exchanged beacons among vehicles to improve traffic safety. However, as the number of connected vehicles increases, the network may become congested due to periodically exchanged beacons. Therefore, without some congestion control method, safety critical messages such as Cooperative Awareness Messages (CAMs) may not be delivered on time in high vehicle density scenarios. Both the European Telecommunications Standards Institute (ETSI) and the Institute of Electrical and Electronics Engineers (IEEE) have been working on different standards to support vehicular communication. ETSI dened the Decentralized Congestion Control (DCC) mechanism which adapts transmission parameters (message rate, transmit data rate, and transmit power, etc.) to keep channel load under control. ETSI DCC utilizes a three-state machine with RELAXED, ACTIVE, and RESTRICTIVE states. In this thesis, we implemented this three-state machine by adapting the message rate based on the channel busy ratio (CBR). We name this message-rate based three-state machine DCC-3. DCC-3 has the ability to control channel load; however, it has unfairness and instability problems due to the dramatic parameter changes between states. Therefore, we divided the ACTIVE state of DCC-3 into ve sub-states, and refer to this as DCC-7. We benchmarked DCC-3 against static beaconing (STB), dynamic beaconing (DynB), LInear MEssage Rate Integrated Control (LIMERIC), and DCC-7 using different evaluation metrics with different numbers of platoons. Our results from the Plexe simulator demonstrate that DCC-7 has the best performance when considering all evaluation metrics, including CBR, Inter-reception time (IRT), collisions, safe time ratio, and fairness. Furthermore, we found using transmit power control could greatly improve the performance of CBR and collision rates.

  • 16.
    Besharat Pour, Shiva
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Li, Qi
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Connecting Silos: Automation system for thesis processing in Canvas and DiVA2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As the era of digitalization dawns, the need to integrate separate silos into a synchronized connected system is becoming of ever greater significance. This thesis focuses on the Canvas Learning Management System (LMS) and the Digitala vetenskapliga arkive (DiVA) as examples of separate silos.

    The thesis presents several methods of automating document handling associated with a degree project. It exploits the fact that students will submit their thesis to their examiner via Canvas. Canvas is the LMS platform used by students to submit all their coursework. When the examiner approves the thesis, it will be archived in DiVA and optionally published on DiVA. DiVA is an institutional repository used for research publications and student theses.

    When manually archiving and publishing student theses on DiVA several fields need to be filled in. These fields provide meta data for the thesis itself. The content of these fields (author, title, keywords, abstract, …) can be used when searching via the DiVA portal. It might not seem like a massive task to enter this meta data for an individual thesis; however, given the number of theses that are submitted every year, this process takes a large amount of time and effort. Moreover, it is important to enter this data correctly, which is difficult when manually doing this task. Therefore, this thesis project seeks to automate this process for future theses.

    The proposed solution parses PDF documents and uses information from the LMS in order to automatically generate a cover for the thesis and fill in the required DiVA meta data. Additionally, information for inserting an announcement of the student's oral thesis presentation into a calendar system will be provided. Moreover, the data in each case will be checked for correctness and consistency.

    Manually filling in DiVA fields in order to publish theses has been a quite demanding and time-consuming process. Thus, there is often a delay before a thesis is published on DiVA. Therefore, this thesis project’s goal is to provide KTH with an automated means to handle thesis archiving and publication on DiVA, while doing so more efficiently, and with fewer errors. The correctness of the extracted meta data will be evaluated by comparing the results to the previously entered meta data for theses that have previously been achieved in DiVA. The automated process has been calculated to take roughly 50 seconds to prepare the information needed to publish a thesis to DiVA with ~71% accuracy, compared with 1 hour and 34% accuracy in the previous manual method.

  • 17.
    Cavdar, Cicek
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Gera, Damini
    Airbus, Ottobrunn, Germany..
    Ghosh, Ayan
    BT, Bristol, Avon, England..
    Hofmann, Sandra
    Airbus, Ottobrunn, Germany..
    Nordlow, Anders
    Ericsson, Stockholm, Sweden..
    Schupke, Dominic
    Airbus, Ottobrunn, Germany..
    Demonstration of an Integrated 5G Network in an Aircraft Cabin Environment2018In: 2018 IEEE/AIAA 37TH DIGITAL AVIONICS SYSTEMS CONFERENCE (DASC), IEEE , 2018, p. 334-343Conference paper (Refereed)
    Abstract [en]

    The wireless communications finds many applications inside an aircraft cabin, in terms of Passenger and Crew Communications as well as Machine Type Communications (MTC). The aircraft cabin is a challenging environment and the different wireless technologies must be adequately tested and adapted to achieve maximum performance. In this regard, an aircraft environment has been analyzed in this paper for an in-cabin wireless system implementation and the measurement results have been further evaluated. This is an integrated system for the technologies of LTE, LAA and NB-IoT for the potential use-cases of Passenger Connectivity, On-Board Sensing, Cargo Tracking and Passenger Announcement. Results have then been summarized within the scope of this paper.

  • 18.
    Celik, Haris
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Feasibility and Performance of Dynamic TDD in Dense and Ultra-Dense Wireless Access Networks2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Meeting the seemingly never-ending increase in traffic over wireless networks presents a major challenge for future mobile network design. Given that much of the traffic is expected to be more time-varying and unpredictable, time division duplexing (TDD) is gaining increasing favorability in part thanks to its ability to better accommodate network-wide traffic variations. In order to account for traffic variations in individual cells on much shorter time scales, a more flexible variant called dynamic TDD has resurfaced as a promising technique to further improve resource utilization and performance. In dynamic TDD the traffic in each cell can be served immediately in either direction, but generates same-entity interference which is potentially more harmful. To avoid the much stronger downlink from saturating the uplink, this thesis considers dynamic TDD for dense and ultra-dense networks where transmission powers in the two directions are of comparable strength. Still, inter-cell interference remains an issue given the close proximity of some links. Because of the large number of cells comprising dense and ultra-dense networks, it is imperative that the interference management be both effective and scalable, which is the main focus of this thesis.

    In the first part we focus on scalable radio resource management (RRM). We show that non-cooperative dynamic TDD is feasible for indoor ultra-dense deployment and highlight the benefit of employing beamsteering at both the base station (BS) and user equipment (UE) to mitigate interference distributively, especially at high load. Recognizing that beamsteering is better suited for higher frequencies and high data rate applications, we proceed to investigate the efficacy of receive-side interference management in the form of successive interference cancellation (SIC). Being that the interference distribution is different in dynamic TDD, we show that it suffices to cancel only strongest interferer at the UE side and the two strongest interferers at the BS. The combined benefit of SIC and dynamic TDD in reducing delay for low-rate traffic is also displayed. Next, we introduce limited inter-cell information exchange in order to leverage the resource allocation in the medium access control (MAC). To minimize the amount of information exchange and preserve scalability, a scheduling framework is proposed that relates real-time traffic to inter-BS interferences measured offline and mapped to the individual activation probability of each BS. The proposed scheme is shown to perform well with respect to comparable scalable schedulers when interference is high, and optimally when interference is low.

    In ultra-dense networks it is expected that some BSs might not have a UE to serve. In the second part, we therefore introduce cooperation to utilize the otherwise idle BSs to improve network performance. To mitigate both same- and other-entity interference, zero forcing (ZF) precoding is employed where not only downlink UEs but also uplink BSs are included in the beamforming. Results show that both uplink and downlink performance improves at low and medium load, and that it is possible to trade performance in the two directions at high load.

  • 19.
    Celik, Haris
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Sung, Ki Won
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Efficacy of Successive Interference Cancellation in Dynamic TDD Cellular NetworksManuscript (preprint) (Other academic)
  • 20.
    Celik, Haris
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Sung, Ki Won
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Success Probability of Successive Interference Cancellation in Random Wireless NetworksManuscript (preprint) (Other academic)
  • 21.
    Chang, Peiliang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Cross-Layer Energy-Efficient Mobile Network Design2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    To assure the sustainable development of mobile networks, it is crucial to improve their energy efficiency. This thesis is devoted to the design of energy-efficient mobile networks. A cross-layer design approach is adopted. The resource management at the MAC layer, the network layer as well as the service layer are optimized to improve the energy efficiency of mobile networks. The problem of optimizing the MAC-layer resource allocation of the downlink transmission in multi-carrier NOMA systems to maximize the system energy efficiency while satisfying users’ QoS requirements is firstly considered. The optimal power allocation across sub-carriers and across users sharing one sub-carrier are proposed. Furthermore, exploiting the structure of the optimal power allocation across users sharing one sub-carrier, a sub-optimal solution for sub-carrier assignment, which greedily minimizes the required power to serve all users with required QoS, is developed. Besides optimizing the channel assignment and power allocation within a single cell, the link scheduling in the multi-cell scenario to deal with inter-cell interference is also studied. A scalable distributed link scheduling solution is proposed to orchestrate the transmission and DTX micro-sleep of multiple base stations such that both the inter-cell interference and the energy consumption are reduced. At the network layer, the operation of base station sleeping is optimized to improve the energy efficiency of mobile networks without deteriorating users’ QoS. The spectral and energy efficiency of mobile networks, where base stations are enabled with DTX, under different traffic load is firstly studied. It shows that as the networks are more loaded, the link spectral efficiency reduces while the network spectral efficiency increases. Regarding the network energy efficiency, it will either firstly increase and then decrease or always increase when the network load gets higher. The optimal network load to maximize the network energy efficiency depends on the power consumption of base stations in DTX sleep mode. Based on the findings of the above study, the joint optimization of cell DTX and deep sleep to maximize the network energy efficiency is investigated. A scaling law of transmit power, which assures that the distribution of the received power remains unchanged as more base stations are switched into deep sleep, is proposed. Then the average resource utilization and overload probability of non-deep-sleep base stations are derived. Based on these results, the feasible range of the percentage of deep-sleep base stations is obtained. Finally, the optimal percentage of deep-sleep base stations to maximize the network energy efficiency while satisfying users’ QoS requirements is derived. Lastly, the service-layer resource provision of edge computing in mobile networks is optimized to improve the energy efficiency. With this work, the trade-offs on service latency and energy consumption between the computation and the communication subsystems are studied. It is shown that the load of the communication subsystem and that of the computation subsystem should be balanced. Increasing the resource of the highly loaded subsystem can significantly reduce the required resource of the other subsystem. An algorithm is proposed to find out the optimal processing speed and the optimal number of active base stations that minimizes the overall energy consumption while assuring the requirements on the mean service latency.

  • 22.
    Chang, Peiliang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Energy-Efficient Resource Allocation in Multi-Carrier NOMA SystemsManuscript (preprint) (Other academic)
    Abstract [en]

    5G cellular networks are expected to support heterogeneous services with the same level of energy dissipation as current cellular networks. As a key enabler of 5G [1], the energy efficiency performance of non-orthogonal multiple access (NOMA) is of paramount importance. In NOMA systems, the system performance, e.g., spectral efficiency and energy efficiency are largely affected by resource allocation, i.e., sub-carrier assignment and power allocation. This paper studies the joint sub-carrier assignment and power allocation for the downlink transmission of multi-carrier NOMA systems to maximize the system energy efficiency (SEE). We first formulate an energyefficiency maximization problem while assuring the connectivity requirements of all users. The original optimization problem is a mixed integer programming problem and is NP hard. In order to develop optimal solutions with low complexity, the formulated problem is decomposed into three sub-problems: sub-carrier assignment, power allocation across sub-carriers and power allocation among users sharing the same sub-carrier. Given subcarrier assignment, we first obtain the optimal power allocation among users on one sub-carrier and then the optimal power allocation across sub-carriers. To find the optimal sub-carrier assignment, a greedy search solution based on the intrinsic structure of the transmitted power is proposed to minimize the overall required power to support the connectivity requirements of all users. Numerical simulations are implemented to validate the analytical findings. The results show that our proposed algorithms achieve better system energy efficiency and lower user blocking rate than the state-of-the-art solutions in the literature.

  • 23.
    Chang, Peiliang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Interference-aware Distributed Control of Cell Discontinuous Transmission2018In: 2018 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC), IEEE , 2018Conference paper (Refereed)
    Abstract [en]

    As a main enabler for the next generation (5G) cellular networks, network densification faces challenges in intercell interference and energy consumption. Cell discontinuous transmission (DTX) can be employed to reduce both energy consumption of base stations (BSs) and inter-cell interference. In this paper we study the control problem of cell DTX in dense small cell networks (DSCNs). We firstly formulate the network energy efficiency optimization problem. Then a centralized heuristic DTX control algorithm is presented. In order to address the issues of complexity and scalability of the centralized solution, an interference-aware distributed DTX control algorithm is proposed. Discussions on algorithm complexity and implementation are provided. The proposed algorithms are evaluated with numerical simulations. Results show that at high load region, the proposed algorithms can not only enhance network capacity by reducing inter-cell interference by up to 60% but also increase network energy efficiency by switching BSs into micro-sleep mode by 67%.

  • 24.
    Chang, Peiliang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Optimal Operation of Base Stations With Deep Sleep and Discontinuous TransmissionIn: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359Article in journal (Refereed)
    Abstract [en]

    Traffic-aware base station (BS) sleeping is a promising approach to increase the energy efficiency (EE) of cellular networks. Both deep sleep and discontinuous transmission (DTX)can be applied to improve network EE. This paper studies the optimal BS operation when both deep sleep and DTX are employed. Queuing theory and stochastic geometry theory are jointly applied to model network performance considering both traffic dynamics and stochastic channel quality. We firstly propose a scaling law of transmit power that assures network coverage. Then, we characterize the resource utilization of active BSs when various percent-ages of BSs are switched into deep sleep, and analyze the overload probability of the remaining active BSs. Finally, we investigate the impact of BS deep sleep and DTX micro sleep on network EE. Both analytical and simulation results show that there is a trade-off between deep sleep and DTX micro sleep. Switching BSs into deep sleep would increase the load of the remaining active BSs and reduce their energy saving achieved with DTX. When the power consumption of BS in DTX micro-sleep mode is considerably low, switching BSs into deep sleep might increase the overall energy consumption, and it is not always the best practice to switch as many BSs into deep sleep as possible to maximize network EE.

  • 25.
    Chang, Peiliang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Resource Provision for Energy-Efficient Mobile Edge Computing2018In: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings, IEEE Communications Society, 2018, article id 8648008Conference paper (Refereed)
    Abstract [en]

    Mobile Edge Computing (a.k.a Fog computing) is recently proposed to provide computing service for delay-sensitive mobile applications. Despite various benefits, deploying edge servers in cellular networks would increase their energy consumption. In this paper, we investigate the provision of resources, including both communication and computation resources, of Mobile Edge Computing (MEC) systems to improve their energy efficiency (EE). In a MEC system, both the communication subsystem, which allows mobile users to access Internet and offload their computing tasks, and the computation subsystem, which accomplishes the offloaded computing tasks, affect the service latency and consume energy. Modelling the whole system as tandem queues, we study the trade-offs between these two subsystems on energy consumption and service latency. Based on the analysis results, we propose an algorithm to determine the optimal provision of both communication and computation resources to minimize the overall energy consumption without sacrificing the performance on service latency. Numerical results are provided to validate our analytical findings.

  • 26.
    Eneroth, Nathanael
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Securing LBO VoLTE roaming with multiple Escrow Agents: A dynamic approach to distribute cryptographic keys to Escrow Agents2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The fourth generation cellular mobile broadband, Long-Term Evolution (LTE), provides high speed Internet via Internet Protocol (IP). Today’s wireless infrastructure paves the way to a connected society where high speed Internet is seamlessly available at all times for anyone to use. To achieve this, a mobile service subscriber can no longer be bound to a single network provided by a single operator. Thus, roaming constitutes a key pillar in shaping the connected society

    Local Breakout (LBO) Voice over Long-Term Evolution (VoLTE) roaming enables a mobile service subscriber to breakout from its home network, and to use network services in a visited network. LBO requires control signalling and user data to be routed over several Public Land Mobile Networks (PLMNs), thus making mobile service subscriber’s the subject of Lawful Intercept (LI) across multiple networks.

    This thesis project investigates the possibility of using Multimedia Internet KEYing (MIKEY) and Secure Real-Time Transport Protocol (SRTP) to encrypt the payload of VoLTE media packets. More specifically, a Law Enforcement Monitoring Provider (LEMP) is designed, implemented, and evaluated. LEMP is deployed within a cell phone and serves to distribute cryptographic key shares to Trusted Third Parties (TTPs), i.e. multiple escrow agents, entrusted to store these cryptographic key shares. The result preserves the requirements for LI despite the fact that there may be multiple network operators involved. Moreover, the experiments show that the distribution time depends primarily on network latency rather than the time required to split the cryptographic key in chunks; hence the approach is usable in practice.

  • 27.
    Friðriksson, Vilhelm
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Container overhead in microservice systems2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Containers have been gaining popularity in recent years due to their ability to provide higher flexibility, higher reliability and dynamic scalability to enterprise software systems. In order to fully utilize containers, software developers aim to build their software using microservice architecture, meaning that instead of working on a single large codebase for the whole project, the software is split into smaller units. These microservices can be deployed in their own container instead of the traditional virtual machine setup where a server has to configured with all necessary dependencies. Moving away from the monolithic software architecture to containerized microservices is bound to bring performance penalties due to increased network calls between services and container overhead. The integration must therefor be carefully planned in order to fully utilize the container setup while minimizing the overhead. The purpose of this thesis project was to measure how much overhead can be expected due to containers in an enterprise environment. By using a combination of virtual machines and Docker containers, a microservice system was deployed with four different deployment strategies and the system’s performance was measured by analyzing request response times under various loads. The services were made to run on a single server and on multiple servers, with and without Docker. The performance measurements showed that the system performed worse in every case when Docker was used. Furthermore, the results showed that Docker can have significant negative impact on performance when there is a heavy load on the system.

  • 28.
    Ghanbari, Amirhossein
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Alvarez Alvarez, Oscar
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH Royal Inst Technol, Sch Informat & Commun Technol ICT, Dept Commun Syst CoS, Stockholm, Sweden..
    Coopetition in M2M Ecosystem - The Case of Smart Cities2015In: 2015 12TH ANNUAL IEEE INTERNATIONAL CONFERENCE ON SENSING, COMMUNICATION, AND NETWORKING - WORKSHOPS (SECON WORKSHOPS), IEEE , 2015, p. 13-18Conference paper (Refereed)
    Abstract [en]

    During recent years, there has been an increasing interest in the potential opportunities that can be attained with promoting Smart Sustainable Cities (SSC); a concept that can be reached based on Information and Communication Technology (ICT). The SSC concept is then considered achievable by horizontal integration of participating industries in its ecosystem in order to empower sustainability. This approach requires cooperation and sharing resources among co-existing multiple industrial verticals as well as collaboration among competitors (Coopetition). As a result, Machine to Machine (M2M) communications, as the most relevant subcategory of ICT in this context, requires proper coopetition patterns in its ecosystem. In this paper we identify the major roles (activities) in the M2M ecosystem in the context of Smart Cities. Next we define the actors who are capable of performing these roles and present a diagram showing plausible business relations among them. Eventually we discuss the complexity of resources in this context and present different forms of sharing resources among participating actors that is based on coopetition.

  • 29.
    Hossain, M. Istiak
    et al.
    KTH.
    Laya, Andres
    KTH.
    Militano, Francesco
    Ericsson Res, Bangalore, Karnataka, India..
    Iraji, Sassan
    Aalto Univ, Aalto, Finland..
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Reducing Signaling Overload: Flexible Capillary Admission Control for Dense MTC over LTE Networks2015In: 2015 IEEE 26TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC), IEEE , 2015, p. 1305-1310Conference paper (Refereed)
    Abstract [en]

    The increasing adoption of Machine-Type Communication (MTC) applications on existing Long Term Evolution (LTE) brings new challenges for traditional signaling mechanism and system capacity. MTC is related to high number of devices; which represents a challenge when performing control and signaling procedures required for getting resource grant, since these processes are inefficient compared to the actual resource usage for small data transmissions. Solutions based on device grouping propose a static grouping approach, which does not perform well in low load scenario. This paper introduces the notion of a flexible admission/connection that can give granular group device control to Core network. With the proposed approach devices can be grouped for a certain period of time under supervision and control of a gateway and they can be ungrouped when there is no need for grouping them together. In this way, a finer control can be achieved on prioritizing certain services and load balancing. Our simulation results demonstrate significant signaling reduction by using this simple scheme compared to conventional connection procedure.

  • 30.
    Hossain, Mohammad Istiak
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Lin, Lu
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    A Comparative Study of IoT-Communication Systems Cost Structure: Initial Findings of Radio Access Networks Cost2018In: 11th CMI International Conference, 2018: Prospects and Challenges Towards Developing a Digital Economy within the EU, PCTDDE 2018 / [ed] Williams, I, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 49-55, article id 8624853Conference paper (Refereed)
    Abstract [en]

    This techno-economic study introduces a framework to study the deployment cost of IoT radio access network and to compare the cost and capacity of LPWAN, LPLAN, and Cellular-IoT systems. There are a plethora of Communication technologies available today. Small rollout and pilot projects are visible for most of the IoT connectivity technologies. However, The economic viability of cellular and non-cellular IoT connectivity technologies are not definite. The primary objective of this work is to analyze the cost structure of SigFox, LoRaWAN, NB-IoT, and WiFi-HaLow. In this paper, we study an urban scenario with the consideration of an Greenfield and Brownfield actor to understand the technology selection strategy of communication service prodvider's perspective. One of our findings indicates that the maintenance cost is the key cost driver for IoT radio access networks. We also point out certain bounds where a technology is potentially cost-effective.

  • 31.
    Hossain, Mohammad Istiak
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH Royal Inst Technol, Sch Informat & Commun Technol, Stockholm, Sweden..
    IoT-Communications as a Service: Actor Roles on Indoor Wireless Coverage2017In: 2017 JOINT 13TH CTTE AND 10TH CMI CONFERENCE ON INTERNET OF THINGS - BUSINESS MODELS, USERS, AND NETWORKS / [ed] Falch, M, IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    Internet of Things (IoT) is anticipated as a 'game changer' for communication service providers. Numerous IoT devices will deploy in areas where humans already inhabit. It is increasing the importance of indoor area coverage to support IoT services. This again brings the historically important questions, 'what roles an actor play and who will control the indoor coverage?' In this paper, we discuss the business actors' roles in IoT indoor service context. We identify the possible roles and activities needed to provide end-to-end indoor IoT services. Additionally, we analyze the actors' roles in IoT ecosystem. We compare the actors' roles in the context of the suitable technology and deployment choices. Our identification of roles and initial analysis shows the impact of technology and rollout choices over network business strategy. With our presented analysis, we evaluate the possible paths for mobile network operators (MNOs) on low-power wide area (LPWAN) or low-power wireless local area (LPWLAN) network deployment.

  • 32.
    Jan, Jonathan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Collecting Data for Building Automation Analytics: A case study for collecting operational data with minimal human intervention2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Approximately 40% of the total energy consumption within the EU is due to buildings, and similar numbers can be found in the US. If the principal inefficiencies in buildings were easily identifiable, then a facility manager could focus their resources to make the buildings more efficient, which would lead to both cost savings for the facility owners and decrease the building’s ecological footprint.

    In building automation systems today, data is already being collected every second, but due to the lack of standardization for describing this data, having access to data is not the same as being able to make use of it. The existing heterogeneity makes it very costly to gather data from multiple buildings, thus making it difficult to understand the big picture.

    Facility managers cannot fix what they cannot see; thus it is important to facilitate the visualization of the data collected from all of the different building automation systems. This potentially offers great benefits with regards to both sustainability and economy. In this thesis, the author’s goal is to propose a sustainable, cost and time effective data integration strategy for real estate owners who wish to gain greater insight into their buildings’ efficiency. The study begins with a literature study to find previous and on-going attempts to solve this problem. Some initiatives for standardization of semantic models were found. Two of these models, Brick and Haystack, were chosen. One building automation system (BAS) was tested in a pilot case study, to test the appropriateness of a solution.

    The key results from this thesis project show that data from building automation systems, can be integrated into an analysis platform, and an extract, transform, and load (ETL) process for this is presented. How time efficiently data can be tagged and transformed into a common format is very dependent upon the current control system’s data storage format and whether information about its structure is adequate. It is also noted that there is no guarantee that facility managers have access to the control system’s database or information about how that is structured, in such cases other techniques can be used such as BACnet/IP, or Open Platform Communications (OPC) Unified Architecture.

  • 33.
    Karapantelakis, Athanasios
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Challenges for ICT Business Development in Intelligent Transport Systems2017In: 2017 JOINT 13TH CTTE AND 10TH CMI CONFERENCE ON INTERNET OF THINGS - BUSINESS MODELS, USERS, AND NETWORKS / [ed] Falch, M, Institute of Electrical and Electronics Engineers (IEEE), 2017Conference paper (Refereed)
    Abstract [en]

    Intelligent Transportation Systems (ITS) are a product of convergence of Information and Communication Technology (ICT) and transport industries, with an aim to improve safety, mobility and efficiency of transportation. Ubiquitous, fast and inexpensive wireless communication and increasing vehicle computation, storage and sensing capabilities, are technological enablers for ITS. Notwithstanding technological maturity, the real challenge rises from the change the ITS market brings to the business of ICT players, as development of ITS services requires cooperation of multiple actors across industries. For ICT players, this signifies a departure from rigid telecom-era business models to a more networked structure of collaboration with other players. In this paper, we identify key business challenges that ICT players face in ITS market, by analysis of two ITS use cases.

  • 34.
    Katsikas, Georgios P.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Network Systems Laboratory (NS Lab). RISE SICS.
    Barbette, Tom
    University of Liege.
    Kostic, Dejan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Steinert, Rebecca
    RISE SICS.
    Maguire Jr., Gerald Q.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Metron: NFV Service Chains at the True Speed of the Underlying Hardware2018Conference paper (Refereed)
    Abstract [en]

    In this paper we present Metron, a Network Functions Virtualization (NFV) platform that achieves high resource utilization by jointly exploiting the underlying network and commodity servers’ resources. This synergy allows Metron to: (i) offload part of the packet processing logic to the network, (ii) use smart tagging to setup and exploit the affinity of traffic classes, and (iii) use tag-based hardware dispatching to carry out the remaining packet processing at the speed of the servers’ fastest cache(s), with zero inter-core communication. Metron also introduces a novel resource allocation scheme that minimizes the resource allocation overhead for large-scale NFV deployments. With commodity hardware assistance, Metron deeply inspects traffic at 40 Gbps and realizes stateful network functions at the speed of a 100 GbE network card on a single server. Metron has 2.75-6.5x better efficiency than OpenBox, a state of the art NFV system, while ensuring key requirements such as elasticity, fine-grained load balancing, and flexible traffic steering.

  • 35.
    Khosravi, Sara
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Shokri-Ghadikolaei, Hossein
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems Engineering.
    Petrova, Marina
    Efficient Beamforming for Mobile mmWave Networks2019Conference paper (Refereed)
    Abstract [en]

    We design a lightweight beam-searching algorithmfor mobile millimeter-wave systems. We construct and maintaina set of path skeletons, i.e., potential paths between a user and theserving base station to substantially expedite the beam-searchingprocess. To exploit the spatial correlations of the channels, wepropose an efficient algorithm that measures the similarity ofthe skeletons and re-executes the beam-searching procedure onlywhen the old one becomes obsolete. We identify and optimizeseveral tradeoffs between: i) the beam-searching overhead andthe instantaneous rate of the users, and ii) the number of usersand the update overhead of the path skeletons. Simulation resultsin an outdoor environment with real building map data show thatthe proposed method can significantly improve the performanceof beam-searching in terms of latency, energy consumption andachievable throughout.

  • 36.
    Kim, Donggu
    et al.
    Korea Adv Inst Sci & Technol, Sch Elect Engn, Daejeon 34141, South Korea..
    Yang, Yanpeng
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Sung, Ki Won
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Kang, Joonhyuk
    Korea Adv Inst Sci & Technol, Sch Elect Engn, Daejeon 34141, South Korea..
    Cooperation Strategies for Partly Wireless C-RAN2018In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, no 6, p. 1248-1251Article in journal (Refereed)
    Abstract [en]

    This letter presents a variant of cloud radio access network (C-RAN) architecture, which we term partly wireless C-RAN (PW-CRAN). It is characterized by extra radio nodes connected through the existing remote radio heads. Because of the newly connected nodes and the consequent additional delay, the operation of PW-CRAN requires different approaches compared with that of the typical C-RAN. Specifically, the effect of delayed channel state information on the suitability of network cooperation should be identified. To tackle this problem, we introduce two representative cooperation strategies and evaluate the performance with regard to the delay via simulations. Numerical results suggest that it is better to exclude the extra nodes from cooperation if they incur excess delay. Furthermore, whether the delay is deemed excessive depends on the interference environment. Hence, we provide quantified guidelines on the cooperation strategy of PW-CRAN.

  • 37.
    Kwon, Younggap
    et al.
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 120749, South Korea.;Agcy Def Dev, Daejeon 305600, South Korea..
    Park, Hyunsung
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 120749, South Korea..
    Oh, Jintaek
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 120749, South Korea..
    Miao, Guowang
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Hwang, Taewon
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 120749, South Korea..
    Energy-Efficient Routing and Link Adaptation for 2D Wireless Relay Networks in the Wideband Regime2018In: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 17, no 11, p. 7325-7339Article in journal (Refereed)
    Abstract [en]

    We discuss the globally optimal energy-efficient design of a 2D relay network. Different from the existing routing protocols on energy saving, which finds the minimal energy route for a given data rate, the proposed algorithm jointly optimizes routing and data rate to maximize energy efficiency (EE) defined as the achievable data rate per power consumption. We propose a low-complexity algorithm to circumvent the huge complexity of the exhaustive search for the network EE maximization and prove its global optimality. Moreover, the proposed algorithm is implemented in a distributed fashion because each relay needs to send its routing information only to the relays in its adjacent tiers, which significantly reduces the signaling overhead of the centralized implementation. Our analysis on the worst-case complexity in a fading channel shows that the complexity of the proposed algorithm increases linearly while that of the exhaustive search increases exponentially as the tier index increases. Simulation results confirm that the proposed algorithm outperforms the existing routing protocols on energy saving and achieves the globally optimal network EE at a significantly lower complexity than the exhaustive search.

  • 38.
    Laya, Andrés
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Lundberg, Stefan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Ergonomics.
    Network-centric business models for health, social care and wellbeing solutions in the internet of things2018In: Scandinavian Journal of Management, ISSN 0956-5221, E-ISSN 1873-3387, Vol. 34, no 2, p. 103-116Article in journal (Refereed)
    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-level and also at a network-level. The network-level analysis is 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 without 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.

  • 39.
    Liu, Fei
    et al.
    Rhein Westfal TH Aachen, Inst Networked Syst, D-52072 Aachen, Germany..
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Dynamic Power Allocation for Downlink Multi-Carrier NOMA Systems2018In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, no 9, p. 1930-1933Article in journal (Refereed)
    Abstract [en]

    In this letter, the performance of optimal dynamic power allocation (PA) is analyzed for downlink multi-carrier non-orthogonal multiple access (MC-NOMA) systems. We study the PA optimization problem with a pair of users and weighted-sum-rate utility. A novel low-complexity algorithm is designed to solve the problem with a closed-form PA expression. The analytical data rate performance is derived and verified by simulation results. The numerical results indicate that a large difference in user channel states improves performance by enhancing the user diversity gain in NOMA systems. Moreover, the channel diversity gain can be achieved by multi-carrier transmission and increases with the number of subcarriers. Finally, the number of subcarriers for dynamic PA in MC-NOMA systems is discussed for practical applications.

  • 40.
    Liu, Fei
    et al.
    Rhein Westfal TH Aachen, Inst Networked Syst, D-52072 Aachen, Germany..
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Performance of Proportional Fair Scheduling for Downlink PD-NOMA Networks2018In: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 17, no 10, p. 7027-7039Article in journal (Refereed)
    Abstract [en]

    In this paper, we present an analytical model for performance analysis of dynamic proportional fair scheduling (PFS) in downlink power-domain non-orthogonal multiple access (PD-NOMA) networks. In order to develop a tractable model of analytical performance, we relax the condition in the PFS optimization problem and assume an ideal NOMA system with an arbitrary number of multiplexed users per frame. We derive a closed-form solution of the optimal power allocation for the relaxed problem and design a low-complexity algorithm for joint power allocation and user set selection. With this optimal solution, the transmission performance in the ideal NOMA system is proved to be an upper bound. Based on our derivation, we develop an analytical model of the upper bound throughput performance. The analytical performance is used to estimate user data rates and overall throughput in practical NOMA systems. We conduct system-level simulations to evaluate the accuracy of our data rate estimation. The simulation results verify our analysis of the upper bound performance of PFS in NOMA systems and confirm that using its analytical results for data rate estimation guarantees high accuracy. The impact of partial and imperfect channel state information on the estimation performance is investigated as well.

  • 41.
    Ly, Steven
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Dynamic Pricing Communication2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Parking is an old concept, which fundamentally involves leaving a vehicle at a place. Parking has been considered as a subsidiary activity to owning a car. However, these days owning a car has become the norm, which leads to a greater demand for parking. Unregulated parking demand often leads to increased traffic congestion, when there are not enough parking spaces to keep up with the demand. Congestion itself has a negative impact on the environment and causes safety issues. A common solution to reduce congestion have been by influencing the demand for parking spaces through parking prices. During recent years, the existing pricing strategies have not been able to keep up with the daily changes in demand. Therefore, stakeholders in the parking industry have started to shift towards working for dynamic pricing.

    Dynamic pricing utilizes a pricing strategy that sets the price according to the current demand and occupancy. However, the parking industry is missing a key feature to fully enable dynamic pricing. There is no communication standard in the parking industry. Thus, there is no efficient communication mean for the stakeholders to share their parking-related information (such as location, occupancy, and tariff data). This thesis has developed and proposes a protocol for sharing such parking-related information. The aim is that the protocol will be used as a communication standard in the parking industry. Due to limited time, the most focus was put on completing the protocol for tariff data. However, the developed protocol can be considered as a partial solution towards dynamic pricing. Because the protocol can still be used to properly share tariff data.

    Based on the evaluation, the protocol could express a variety of tariffs. The tariffs that are expressible have use cases such as early bird, residential, or on-street parking. To make integration easier, for the parking industry, the protocol includes tools to aid integrations of the protocol. A future work will be to complete the support of location and occupancy related data. Additionally, it has been discussed that the protocol will onwards be developed as open-source.

  • 42.
    Masoudi, Meysam
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Green Mobile Networks for 5G and Beyond2019In: IEEE Access, E-ISSN 2169-3536Article in journal (Refereed)
    Abstract [en]

    The heated 5G network deployment race has already begun with the rapid progress in standardization efforts, backed by the current market availability of 5G-enabled network equipment, ongoing 5G spectrum auctions, early launching of non-standalone 5G network services in a few countries, among others. In this article, we study current and future wireless networks from the viewpoint of energy efficiency (EE) and sustainability to meet the planned network and service evolution towards, along, and beyond 5G, as also inspired by the findings of the EU Celtic-Plus SooGREEN Project. We highlight the opportunities seized by the project efforts to enable and enrich this green nature of the network as compared to existing technologies. In specific, we present innovative means proposed in SooGREEN to monitor and evaluate EE in 5G networks and beyond. Further solutions are presented to reduce energy consumption and carbon footprint in the different network segments. The latter spans proposed virtualized/cloud architectures, efficient polar coding for fronthauling, mobile network powering via renewable energy and smart grid integration, passive cooling, smart sleeping modes in indoor systems, among others. Finally, we shed light on the open opportunities yet to be investigated and leveraged in future developments.

  • 43.
    Masoudi, Meysam
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Azari, Amin
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Yavuz, E. A.
    Ericsson AB, Stockholm, Sweden.
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Grant-Free Radio Access IoT Networks: Scalability Analysis in Coexistence Scenarios2018In: IEEE International Conference on Communications, Institute of Electrical and Electronics Engineers Inc. , 2018Conference paper (Refereed)
    Abstract [en]

    IoT networks with grant-free radio access, like SigFox and LoRa, offer low-cost durable communications over unlicensed band. These networks are becoming more and more popular due to the ever-increasing need for ultra durable, in terms of battery lifetime, IoT networks. Most studies evaluate the system performance assuming single radio access technology deployment. In this paper, we study the impact of coexisting competing radio access technologies on the system performance. Considering K technologies, defined by time and frequency activity factors, bandwidth, and power, which share a set of radio resources, we derive closed-form expressions for the successful transmission probability, expected battery lifetime, and experienced delay as a function of distance to the serving access point. Our analytical model, which is validated by simulation results, provides a tool to evaluate the coexistence scenarios and analyze how introduction of a new coexisting technology may degrade the system performance in terms of success probability and battery lifetime. We further investigate solutions in which this destructive effect could be compensated, e.g., by densifying the network to a certain extent and utilizing joint reception.

  • 44.
    Masoudi, Meysam
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Azari, Amin
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Yavuz, Emre Altug
    Ericsson AB, Stockholm, Sweden.
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Grant-free Radio Access IoT Networks:Scalability Analysis in Coexistence Scenarios2018Conference paper (Refereed)
    Abstract [en]

    IoT networks with grant-free radio access, likeSigFox and LoRa, offer low-cost durable communications overunlicensed band. These networks are becoming more and morepopular due to the ever-increasing need for ultra durable, interms of battery lifetime, IoT networks. Most studies evaluatethe system performance assuming single radio access technologydeployment. In this paper, we study the impact of coexistingcompeting radio access technologies on the system performance.Considering K technologies, defined by time and frequencyactivity factors, bandwidth, and power, which share a set of radioresources, we derive closed-form expressions for the successfultransmission probability, expected battery lifetime, and experienceddelay as a function of distance to the serving access point.Our analytical model, which is validated by simulation results,provides a tool to evaluate the coexistence scenarios and analyzehow introduction of a new coexisting technology may degrade thesystem performance in terms of success probability and batterylifetime. We further investigate solutions in which this destructiveeffect could be compensated, e.g., by densifying the network toa certain extent and utilizing joint reception.

  • 45.
    Munari, Andrea
    et al.
    Rhein Westfal TH Aachen, Inst Networked Syst, D-52072 Aachen, Germany..
    Simic, Ljiljana
    Rhein Westfal TH Aachen, Inst Networked Syst, D-52072 Aachen, Germany..
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Stochastic Geometry Interference Analysis of Radar Network Performance2018In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 22, no 11, p. 2362-2365Article in journal (Refereed)
    Abstract [en]

    This letter characterizes the effect of mutual interference in a planar network of pulsed-radar devices. Using stochastic geometry tools and the strongest interferer approximation, we derive simple closed-form expressions that pinpoint the role played by key system parameters on radar detection range and false alarm rate. The fundamental tradeoffs of the system between radar performance, network density, and antenna directivity are captured for different path-loss exponents in the no-fading and Rayleigh-fading cases. The discussion highlights practical design hints for tuning the radar parameters. The accuracy of the model is verified through network simulations.

  • 46.
    Mårtensson, Charlie
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Kaisoum, Adam
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Evaluating HORNET2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Anonymity services are an increasingly important platform for anonymity and integrity in today’s society. HORNET anonymity service is a system that enables high-speed anonymous channels by exploiting next-generation network architectures. The purpose of this thesis was to contribute more work on HORNET to the scientific community and to increase the understanding of its performance and scalability. The goal was to identify the system aspects that primarily limit HORNET's scalability and performance. To achieve the goal, a profiling program was used in a quantitative study to estimate the execution time of the different HORNET phases. The results show that HORNET's setup phase primarily limits the scalability of the system, but that it does not affect its performance. The results also show that HORNET's data phase is efficient and scale well.

  • 47.
    Patra, Avishek
    et al.
    Rhein Westfal TH Aachen, Inst Networked Syst, Aachen, Germany..
    Simic, Ljiljana
    Rhein Westfal TH Aachen, Inst Networked Syst, Aachen, Germany..
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    mmRTI: Radio Tomographic Imaging using Highly-Directional Millimeter-Wave Devices for Accurate and Robust Indoor Localization2017In: 2017 IEEE 28TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC), IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    As a device-free approach, radio tomographic imaging (RTI) is ideally suited for low-cost indoor localization in context-aware Internet-of-Things applications. However, the fundamental RTI algorithm relies on shadowing of the line of sight (LOS) links and therefore, conventional RTI implementations using 2.4 GHz sensing networks (microRTI) fail to accurately localize users in multipath-rich indoor environments. The localization accuracy is further degraded by external human movement that affects the signal propagation. In this paper, we propose mmRTI, a novel RTI approach based on a highly-directional, millimeter-wave sensing network, that aims to improve indoor localization by utilizing the LOS-dominant nature of millimeter-wave signal propagation. We experimentally evaluate mmRTI, operating at 60 GHz, with and without human movement around the sensing network, in two indoor environments, and compare its performance against the conventional microRTI approach. We observe that mmRTI achieves a 90%-ile localization error of 0.07 m-0.25 m, an improvement of 2.41 m-2.60m compared to microRTI, while remaining unaffected by external human movement, which degrades the microRTI localization accuracy by up to 1.2 m.

  • 48.
    Ren, Ping
    et al.
    Rhein Westfal TH Aachen, Inst Networked Syst, D-52072 Aachen, Germany..
    Munari, Andrea
    Rhein Westfal TH Aachen, Inst Networked Syst, D-52072 Aachen, Germany..
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Performance Tradeoffs of Joint Radar-Communication Networks2019In: IEEE Wireless Communications Letters, ISSN 2162-2337, E-ISSN 2162-2345, Vol. 8, no 1, p. 165-168Article in journal (Refereed)
    Abstract [en]

    This letter considers a network where nodes share a wireless channel to work in turn as pulse radars for target detection and as transmitters for data exchange. Radar detection range and network throughput are studied using stochastic geometry tools. We derive closed-form expressions that identify the key tradeoffs between radar and communication operations. Results reveal interesting design hints, and stress a marked sensitivity of radar detection to communication interference.

  • 49.
    Shokri-Ghadikolaei, Hossein
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Yang, Yanpeng
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Petrova, Marina
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Sung, Ki Won
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Fischione, Carlo
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Fast and Reliable Initial Cell-search for mmWave Networks2018Conference paper (Refereed)
    Abstract [en]

    In millimeter-wave wireless networks, the use of narrow beams, required to compensate for the severe path-loss, complicates the cell-discovery and initial access. In this paper, we investigate the feasibility of random beam forming and enhanced exhaustive search for cell-discovery by analyzing the latency and detection failure probability in the control-plane and the user throughput in the data-plane. We show that, under realistic propagation model and antenna patterns, both approaches are suitable for 3GPP New Radio cellular networks. The performance gain, compared to the heavily used exhaustive and iterative search schemes, is more prominent in dense networks and large antenna regimes and can be further improved by optimizing the beam forming code-books.

  • 50.
    Tanoh, Henry-Gertrude
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Implementation of Post-Build Configuration for Gateway Electronic Control Unit: Gateway ECU to enable third-party update2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The development of embedded software in the automotive industry has reached a level of complexity, which is unmaintainable by traditional approaches. The AUTomotive Open System Architecture (AUTOSAR) was created to standardize the automotive software. In this architecture, the development of software is spread, in general, between three different entities: Original Equipment Manufacturers (OEMs), e.g. Volvo; Tier-1 Suppliers, such as Vector; and Tier-2 Suppliers, for example, Renesas Microelectronics. Another methodology that has emerged is to develop Electronic Control Units (ECUs) domain wise: infotainment, chassis & safety, powertrain, and body and security. To allow inter-domain communication, the state of art for fast and reliable communication is to use a gateway ECU.

    The gateway ECU is a crucial component in the electrical/electronic (E/E) architecture of a vehicle. In AUTOSAR, a third party, different from the car manufacturer, typically implements the gateway ECU. A major feature for a gateway ECU is to provide highly flexible configuration. This flexibility allows the car manufacturer (OEM) to fit the gateway ECU to different requirements and product derivations.

    This thesis investigates the implementation of post-build configuration for a gateway ECU. First, the thesis provides the reader with some background on AUTOSAR and the current E/E architecture of the gateway ECU. The protocols used by the gateway are explained. The design of a potential solution and its implementation are discussed. The implementation is evaluated through regression tests of the routing functionality. Processing time, memory use, and scaling of the solution are also taken into account.

    The results of the design and the implementation if judged adequate could be used as a springboard to allow post-build in an existing gateway ECU architecture. The results could consolidate the path towards full conformance to AUTOSAR.

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