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  • 201.
    Balador, Ali
    et al.
    SICS Swedish ICT Västerås AB, Västerås, Sweden. & Polytechnic University of Valencia, Valencia, Spain.
    Böhm, Annette
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Calafate, Carlos T.
    Polytechnic University of Valencia, Valencia, Spain.
    Cano, Juan-Carlos
    Polytechnic University of Valencia, Valencia, Spain.
    A Reliable Token-Based MAC Protocol for V2V Communication in Urban VANET2016In: 2016 IEEE 27TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC), Piscataway: IEEE , 2016, p. 1586-1591Conference paper (Refereed)
    Abstract [en]

    Safety applications developed for vehicular environments require every vehicle to periodically broadcast its status information (beacon) to all other vehicles, thereby avoiding the risk of car accidents in the road. Due to the high requirements on timing and reliability posed by traffic safety applications, the current IEEE 802.11p standard, which uses a random access Medium Access Control (MAC) protocol, faces difficulties to support timely and reliable data dissemination in vehicular environments where no acknowledgement or RTS/CTS (Request-to-Send/Clear-to-Send) mechanisms are adopted. In this paper, we propose the Dynamic Token-Based MAC (DTB-MAC) protocol. It implements a token passing approach on top of a random access MAC protocol to prevent channel contention as much as possible, thereby improving the reliability of safety message transmissions. Our proposed protocol selects one of the neighbouring nodes as the next transmitter; this selection accounts for the need to avoid beacon lifetime expiration. Therefore, it automatically offers retransmission opportunities to allow vehicles to successfully transmit their beacons before the next beacon is generated whenever time and bandwidth are available. Based on simulation experiments, we show that the DTB-MAC protocol can achieve better performance than IEEE 802.11p in terms of channel utilization and beacon delivery ratio for urban scenarios.

  • 202.
    Balador, Ali
    et al.
    Halmstad University, School of Information Technology. Universitat Politecnica de València, València, Spain.
    Böhm, Annette
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Uhlemann, Elisabeth
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Mälardalen University, Västerås, Sweden.
    Calafate, Carlos T.
    Universitat Politecnica de València, València, Spain.
    Cano, Juan-Carlos
    Universitat Politecnica de València, València, Spain.
    A Reliable Token-Based MAC Protocol for Delay Sensitive Platooning Applications2015In: 2015 IEEE 82nd Vehicular Technology Conference (VTC2015-Fall), [S.l.]: IEEE, 2015, article id 7390813Conference paper (Refereed)
    Abstract [en]

    Platooning is both a challenging and rewarding application. Challenging since strict timing and reliability requirements are imposed by the distributed control system required to operate the platoon. Rewarding since considerable fuel reductions are possible. As platooning takes place in a vehicular ad hoc network, the use of IEEE 802.11p is close to mandatory. However, the 802.11p medium access method suffers from packet collisions and random delays. Most ongoing research suggests using TDMA on top of 802.11p as a potential remedy. However, TDMA requires synchronization and is not very flexible if the beacon frequency needs to be updated, the number of platoon members changes, or if retransmissions for increased reliability are required. We therefore suggest a token-passing medium access method where the next token holder is selected based on beacon data age. This has the advantage of allowing beacons to be re-broadcasted in each beacon interval whenever time and bandwidth are available. We show that our token-based method is able to reduce the data age and considerably increase reliability compared to pure 802.11p. © 2015 IEEE.

  • 203.
    Balador, Ali
    et al.
    Polytechnic University of Valencia, Valencia, Spain.
    Böhm, Annette
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Uhlemann, Elisabeth
    Mälardalen University, Västerås, Sweden.
    Calafate, Carlos T.
    Polytechnic University of Valencia, Valencia, Spain.
    Ji, Yusheng
    National Institute of Informatics, Tokyo, Japan.
    Cano, Juan-Carlos
    Polytechnic University of Valencia, Valencia, Spain.
    Manzoni, Pietro
    Polytechnic University of Valencia, Valencia, Spain.
    An Efficient MAC Protocol for vehicle platooning in automated highway systems2015Conference paper (Refereed)
    Abstract [en]

    Lately, all the top truck manufacturers are investing considerable resources in the research and development of platooning systems which would allow vehicles to save fuel and improve safety by travelling in a close-following manner. The platooning system requires frequent and reliable vehicle-to-vehicle communications. As platooning takes place in a vehicular ad hoc network, the use of IEEE 802.11p is close to mandatory. However, the 802.11p medium access method suffers from packet collisions and random delays. Most ongoing research suggests using TDMA on top of 802.11p as a potential remedy. However, TDMA requires synchronization and is not very flexible if the beacon frequency needs to be updated, the number of platoon members changes, or if re-transmissions for increased reliability are required. We therefore suggest a token-passing medium access method where the next token holder is selected based on beacon data age. This has the advantage of allowing beacons to be re-broadcasted in each beacon interval whenever time and bandwidth are available. We show that our token-based method is able to reduce the data age and considerably increase reliability considerably compared to pure 802.11p.

  • 204.
    Balasubramaniam, Sasitharan
    et al.
    Tampere University of Technology, Tampere, Finland .
    Lyamin, Nikita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Kleyko, Denis
    Luleå University of Technology, Luleå, Sweden.
    Skurnik, Mikael
    University of Helsinki, Helsinki, Finland .
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Koucheryavy, Yevgeni
    Tampere University of Technology, Tampere, Finland .
    Exploiting bacterial properties for multi-hop nanonetworks2014In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 52, no 7, p. 184-191Article in journal (Refereed)
    Abstract [en]

    Molecular communication is a relatively new communication paradigm for nanomachines where the communication is realized by utilizing existing biological components found in nature. In recent years researchers have proposed using bacteria to realize molecular communication because the bacteria have the ability to swim and migrate between locations, carry DNA contents (i.e. plasmids) that could be utilized for information storage, and interact and transfer plasmids to other bacteria (one of these processes is known as bacterial conjugation). However, current proposals for bacterial nanonetworks have not considered the internal structures of the nanomachines that can facilitate the use of bacteria as an information carrier. This article presents the types and functionalities of nanomachines that can be utilized in bacterial nanonetworks. A particular focus is placed on the bacterial conjugation and its support for multihop communication between nanomachines. Simulations of the communication process have also been evaluated, to analyze the quantity of bits received as well as the delay performances. Wet lab experiments have also been conducted to validate the bacterial conjugation process. The article also discusses potential applications of bacterial nanonetworks for cancer monitoring and therapy. © 2014 IEEE.

  • 205. Baldini, Gianmarco
    et al.
    Kounelis, Ioannis
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. European Commiss, Joint Res Ctr, Inst Protect & Secur Citizen, Ispra, VA, Italy..
    Loeschner, Jan
    Tallacchini, Mariachiara
    European Citizens and Their Trust in Social Networks2014In: Learning and Collaboration Technologies. Technology-Rich Environments for Learning and Collaboration: First International Conference, LCT 2014, Held as Part of HCI International 2014, Heraklion, Crete, Greece, June 22-27, 2014, Proceedings, Part II, Springer International Publishing , 2014Conference paper (Refereed)
    Abstract [en]

    In information and communication technology (ICT) trust has been considered as a crucial component of digital interactions. Trust has been dissected in a variety of potential meanings and dimensions and through the merging of trust in humans and trust in machines. In this paper, we investigate the role and the aggregation of trust in social networks and blogs and how it relates to knowledge production, and its connections to concepts such as reputation and sustainability in the European context. Moreover, we discuss knowledge production in information and communication technology and its relationship to user trust. We develop a view on the co-production of knowledge and trust and propose a policy management framework to support the users in their trusted use of social networks and blogs. This is presented based on an e-health use case analysis considering web based reputation and developing a new reputation scheme.

  • 206. Baliosian, J.
    et al.
    Stadler, Rolf
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Decentralized configuration of neighboring cells for radio access networks2007In: 2007 IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks, WOWMOM, IEEE , 2007, p. 4351740-Conference paper (Refereed)
    Abstract [en]

    In order to execute a handover processes in a Radio Access Network, each cell has a configured list of neighbors to which such handovers are made. Rapid re-configuration of the neigh-borhood list in response to network failures and other events is currently not possible. To address this problem, this paper suggests an autonomic approach for dynamically configuring neighboring cell lists and introduces a decentralized, three-layered framework. As a key element of this framework, a novel probabilistic protocol that detects and continuously tracks the coverage overlaps among cells is presented and evaluated. The protocol, called DOC, maintains a distributed graph of over-lapping cells. Due to using Bloom fillers and aggregation techniques, it exhibits a low traffic and computational overhead. A first series of simulation studies suggests that DOC is scalable with respect to network size and the number of terminals.

  • 207. Bang, I.
    et al.
    Kim, Su Min
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Sung, D. K.
    Opportunistic user selection with adaptive jamming for secure communication in heterogeneous networks2015In: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, IEEE conference proceedings, 2015, p. 42-46Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose an opportunistic user selection criterion to obtain a multiuser diversity gain for secure communication. At the same time, we also propose a strategy for utilizing a small base station in heterogeneous networks as a helper or a jammer adaptively. Our approach is to maximize the secrecy achievable rate based on an analytically derived lower bound instead of the original objective function due to its complexity. Based on a simple proposed user selection criterion considering both macro and small base stations, we propose two jamming strategies according to knowledge of eavesdropper's channel: adaptive jamming and probabilistic jamming strategies. Through simulations in two scenarios, it is shown that our proposed user selection and jamming schemes provide a good performance gain in terms of secrecy achievable rate.

  • 208. Bao, J.
    et al.
    Ma, Z.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Information Science and Engineering. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Tsiftsis, T. A.
    Zhu, Z.
    Performance analysis of uplink sparse code multiple access with iterative multiuser receiver2017In: 2017 IEEE International Conference on Communications, ICC 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, article id 7996537Conference paper (Refereed)
    Abstract [en]

    This paper investigates the asymptotic performance of bit-interleaved coded modulation (BICM) with iterative multiuser detection and decoding in uplink sparse code multiple access (SCMA) systems. The extrinsic information transfer (EXIT) characteristics analysis of the joint multiuser detector for SCMA is provided, and shows that the average detection reliability for multiple users converges to the single-user case, if ideal feedback from the decoder is available to the detector. We develop a tight analytical bound on the convolutionally encoded bit-error rate (BER) for independent Rayleigh fadings, based on the single-user bound with arbitrary multidimensional constellations. Moreover, we analyze the achievable coding and diversity gains of the SCMA-BICM system with iterative receiver. Simulations are carried out to verify the effectiveness of the analysis.

  • 209.
    Barac, Filip
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    Gidlund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    Zhang, Tingting
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    LPED: Channel Diagnostics in WSN Through Channel Coding and Symbol Error Statistics2014In: IEEE ISSNIP 2014 - 2014 IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing, Conference Proceedings, Singapore: IEEE Sensors Council, 2014, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Three major obstacles to wireless communication are electromagnetic interference, multipath fading and signal attenuation. The former stems mainly from collocated wireless systems operating in the same frequency band, while the latter two originate from physical properties of the environment. Identifying the source of packet corruption and loss is crucial, since the adequate countermeasures for different types of threats are essentially different. This problem is especially pronounced in industrial monitoring and control applications, where IEEE 802.15.4 communication is expected to deliver data within tight deadlines, with minimal packet loss. This work presents the Lightweight Packet Error Discriminator (LPED) that distinguishes between errors caused by multipath fading and attenuation, and those inflicted by IEEE 802.11 interference. LPED uses Forward Error Correction to determine the symbol error positions inside erroneously received packets and calculates the error density, which is then fed to a discriminator for error source classification. The statistical constituents of LPED are obtained from an extensive measurement campaign in two different types of industrial environments. The classifier incurs no overhead and in ≥90% of cases a single packet is sufficient for a correct channel diagnosis. Experiments show that LPED accelerates link diagnostics by at least 190%, compared to the relevant state-of-the-art approaches.

  • 210.
    Barac, Filip
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    Gidlund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems. ABB Corp Res, S-72178 Vasteras, Sweden.
    Zhang, Tingting
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    Scrutinizing Bit- and Symbol-Errors of IEEE 802.15.4 Communication in Industrial Environments2014In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 63, no 7, p. 1783-1794Article in journal (Refereed)
    Abstract [en]

    The knowledge of error nature in wireless channels is an essential constituent of efficient communication protocol design. To this end, this paper is the first comprehensive bit- and symbol-level analysis of IEEE 802.15.4 transmission errors in industrial environments. The intention with this paper is to extract the error properties relevant for future improvements of wireless communication reliability and coexistence of radio systems in these harsh conditions. An extensive set of bit-error traces was collected in a variety of scenarios and industrial environments, showing that error behavior is highly dependent on the cause of packet corruption. It is shown that errors inflicted by multipath fading and attenuation exhibit different properties than those imposed by IEEE 802.11 interference. The statistical behavior of these two patterns is concurrently investigated in terms of differences in bit-error distribution, error burst length, channel memory length, and the scale of packet corruption. With these conclusions at hand, abiding to the computational constraints of embedded sensors and the statistical properties of bit-errors, a Reed-Solomon $(15,k)$ block code is chosen to investigate the implications of bit-error nature on practical aspects of channel coding and interleaving. This paper is concluded by a number of findings of high practical relevance, concerning the optimal type, depth, and meaningfulness of interleaving.

  • 211.
    Barac, Filip
    et al.
    Ericsson AB.
    Gidlund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    Zhang, Tingting
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems.
    Sisinni, Emiliano
    University of Brescia.
    Error Manifestation in Industrial WSN Communication and Guidelines for Countermeasures2017In: Wireless Sensor Systems for Extreme Environments: Space, Underwater, Underground and Industrial / [ed] H. F. Rashvand and A. Abedi, John Wiley & Sons, 2017Chapter in book (Refereed)
  • 212.
    Barac, Filip
    et al.
    Mid Sweden University.
    Yu, Kan
    Mälardalen University, School of Innovation, Design and Engineering.
    Gidlund, Mikael
    ABB, Corporate Research.
    Åkerberg, Johan
    ABB, Corporate Research.
    Björkman, Mats
    Mälardalen University, School of Innovation, Design and Engineering.
    Towards Reliable and Lightweight Communication in Industrial Wireless Sensor Networks2012Conference paper (Refereed)
    Abstract [en]

    In this paper we address the issues of timeliness and transmission reliability of existing industrial communication standards. We combine a Forward Error Correction coding schemeon the Medium Access Control layer with a lightweight routing protocol to form an IEEE 802.15.4-conformable solution, whichcan be implemented into already existing hardware without violating the standard. After laying the theoretical foundations,we conduct a performance evaluation of the proposed solution.The results show a substantial gain in reliability and reducedlatency, compared to the uncoded transmissions, as well ascommon Wireless Sensor Network routing protocols.

  • 213. Barkowsky, M
    et al.
    Brunnström, Kjell
    Acreo ICT Swedish AB.
    Ebrahimi, T
    Karam, L
    Lebreton, P
    Le Callet, P
    Perkis, A
    Raake, A
    Subedar, M
    Wang, Kun
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
    Xing, L
    You, J
    Subjective and Objective Visual Quality Assessment in the Context of stereoscopic 3DTV2013In: 3DTV System with Depth-Image-Based Rendering / [ed] Yu, L., Tanimoto, M., and Zhu, C., Springer, 2013, p. 413-437Chapter in book (Refereed)
    Abstract [en]

    Subjective and objective visual quality assessment in the context of stereoscopic three-dimensional TV (3D-TV) is still in the nascent stage and needs to consider the effect of the added depth dimension. As a matter of fact, quality assessment of 3D-TV cannot be considered as a trivial extension of two-dimensional (2D) cases. Furthermore, it may also introduce negative effects not experienced in 2D, e.g., discomfort or nausea. Based on efforts initiated within the cost action ICT 1003 QUALINET, this chapter discusses current challenges in relation to subjective and objective visual quality assessment for stereo-based 3D-TV. Two case studies are presented to illustrate the current state of the art and some of the remaining challenges. © Springer Science+Business Media New York 2013. All rights are reserved.

  • 214.
    Barkowsky, M
    et al.
    University of Nantes, France.
    Masala, E
    Politecnico di Torino, Italy.
    Van Wallendael, G
    Ghent University - iMinds, Belgium.
    Brunnström, Kjell
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information and Communication systems. Acreo Swedish ICT AB, Sweden .
    Staelens, N
    Ghent University - iMinds, Belgium.
    Le Callet, P
    University of Nantes, France.
    Objective Video Quality Assessment - Towards large scale video database enhanced model development.2015In: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E98-B, no 1, p. 2-11Article in journal (Refereed)
    Abstract [en]

    The current development of video quality assessment algorithms suffers from the lack of available video sequences for training, verification and validation to determine and enhance the algorithm's application scope. The Joint Effort Group of the Video Quality Experts Group (VQEG-JEG) is currently driving efforts towards the creation of large scale, reproducible, and easy to use databases. These databases will contain bitstreams of recent video encoders (H.264, H.265), packet loss impairment patterns and impaired bitstreams, pre-parsed bitstream information into files in XML syntax, and well-known objective video quality measurement outputs. The database is continuously updated and enlarged using reproducible processing chains. Currently, more than 70,000 sequences are available for statistical analysis of video quality measurement algorithms. New research questions are posed as the database is designed to verify and validate models on a very large scale, testing and validating various scopes of applications, while subjective assessment has to be limited to a comparably small subset of the database. Special focus is given on the principles guiding the database development, and some results are given to illustrate the practical usefulness of such a database with respect to the detailed new research questions.

  • 215. Baroffio, L.
    et al.
    Canclini, A.
    Cesana, M.
    Redondi, A.
    Tagliasacchi, M.
    Dán, György
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Eriksson, Emil
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Fodor, Viktoria
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Ascenso, J.
    Monteiro, P.
    Demo: Enabling image analysis tasks in visual sensor networks2014In: Proceedings of the 8th ACM/IEEE International Conference on Distributed Smart Cameras, ICDSC 2014, Association for Computing Machinery (ACM), 2014, p. a46-Conference paper (Refereed)
    Abstract [en]

    This demo showcases some of the results obtained by the GreenEyes project, whose main objective is to enable visual analysis on resource-constrained multimedia sensor networks. The demo features a multi-hop visual sensor network operated by BeagleBones Linux computers with IEEE 802.15.4 communication capabilities, and capable of recognizing and tracking objects according to two different visual paradigms. In the traditional compress-then-analyze (CTA) paradigm, JPEG compressed images are transmitted through the network from a camera node to a central controller, where the analysis takes place. In the alternative analyze-then-compress (ATC) paradigm, the camera node extracts and compresses local binary visual features from the acquired images (either locally or in a distributed fashion) and transmits them to the central controller, where they are used to perform object recognition/tracking. We show that, in a bandwidth constrained scenario, the latter paradigm allows to reach better results in terms of application frame rates, still ensuring excellent analysis performance.

  • 216.
    Barrera Diaz, Carlos Alberto
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Oscarsson, Jan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Lidberg, Simon
    Volvo Car Corporation, Skövde, Sweden.
    Sellgren, Tommy
    Volvo Car Corporation, Skövde, Sweden.
    A Study of Discrete Event Simulation Project Data and Provenance Information Management in an Automotive Manufacturing Plant2017In: Proceedings of the 2017 Winter Simulation Conference / [ed] W. K. V. Chan, A. D’Ambrogio, G. Zacharewicz, N. Mustafee, G. Wainer, and E. Page, IEEE, 2017, , p. 12Conference paper (Refereed)
    Abstract [en]

    Discrete Event Simulation (DES) project data management is a complex and important engineering activity which impacts on an organization’s efficiency. This efficiency could be decreased by the lack of provenance information or the unreliability of existing information regarding previous simulation projects, all of which complicates the reusability of the existing data. This study presents an analysis of the management of simulation projects and their provenance data, according to the different types of scenarios usually found at a manufacturing plant. A survey based on simulation projects at an automotive manufacturing plant was conducted, in order to categorize the information regarding the studied projects, map the available provenance data and standardize its management. This study also introduces an approach that demonstrates how a structured framework based on the specific data involved in the different types of scenarios could allow an improvement of the management of DES projects.

  • 217.
    Bassoo, Vandana
    et al.
    Victoria University, Australia.
    Tom, K
    Victoria University, Australia.
    Mustafa, A. K.
    Victoria University, Australia.
    Cijvat, Ellie
    Lunds Universitet.
    Sjöland, Henrik
    Lunds Universitet.
    Faulkner, Mike
    Victoria University, Australia.
    Potential Architecture for Future Generation "Green" Wireless Base Station2009In: 2009 4th International Symposium on Wireless and Pervasive Computing, ISWPC 2009, IEEE, 2009, article id 4800602Conference paper (Refereed)
    Abstract [en]

    Current radio frequency power amplifiers (PAs) in 3G base stations have very high power consumption leading to a hefty cost and negative environmental impact. In this paper, we propose a potential architecture design for future wireless base station. Issues associated with components of the architecture are investigated. A comparison of PA with pulse width modulation drive and PA with envelope elimination and restoration (EER) drive is offered. EER-driven PA promises high efficiency over a wide dynamic range but has bandwidth expansion problems. A novel approach which reduces bandwidth expansion on the envelope by 54% is proposed. A modulator is used to convert amplitude and phase information into the edges of a pulse train. The modulator also eradicates some analog components present in traditional base station design.

  • 218.
    Bassoo, Vandana
    et al.
    Victoria University, Australia.
    Tom, Kevin
    Victoria University, Australia.
    Mustafa, A. K.
    Victoria University, Australia.
    Cijvat, Ellie
    Lund University.
    Sjöland, Henrik
    Lund University.
    Faulkner, Mike
    Victoria University; Australia.
    A potential transmitter architecture for future generation green wireless base station2009In: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, article id 821846Article in journal (Refereed)
    Abstract [en]

    Current radio frequency power amplifiers in 3G base stations have very high power consumption leading to a hefty cost and negative environmental impact. In this paper, we propose a potential architecture design for future wireless base station. Issues associated with components of the architecture are investigated. The all-digital transmitter architecture uses a combination of envelope elimination and restoration (EER) and pulse width modulation (PWM)/pulse position modulation (PPM) modulation. The performance of this architecture is predicted from the measured output power and efficiency curves of a GaN amplifier. 57% efficiency is obtained for an OFDM signal limited to 8 dB peak to average power ratio. The PWM/PPM drive signal is generated using the improved Cartesian sigma delta techniques. It is shown that an RF oversampling by a factor of four meets the WLAN spectral mask, and WCDMA specification is met by an RF oversampling of sixteen.

  • 219.
    Bastani, Saeed
    et al.
    The University of Sydney.
    Landfeldt, Björn
    Lund University.
    Rohner, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Gunningberg, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    A social node model for realising information dissemination strategies in delay tolerant networks2012In: Proceedings of the 15th ACM international conference on Modeling, analysis and simulation of wireless and mobile systems, New york: ACM Press, 2012, p. 79-88Conference paper (Refereed)
    Abstract [en]

    In Delay Tolerant Networks (DTNs) as an emerging content dissemination platform, mobile nodes opportunistically exchange content as they meet, with the intent of disseminating content among nodes that share common interests. During a meeting, nodes can exchange both content of direct interest to themselves as well as content that is of interest to a larger set of nodes that may be encountered in the future. The utility of DTN is governed by the content exchange opportunity (the amount of content that can be exchanged during a meeting) as well as the selection of content to be exchanged in order to maximise the interest nodes will have in information they are exposed to. Considering that there is a cost associated with the content exchange (e.g. battery usage, buffer occupancy or consumed transmission opportunity) the aim for nodes participating in content dissemination should be to maximise their payoff. In this paper, we contribute a generic framework for describing the characteristics of content exchange among participating nodes in a network. We incorporate a distributed information popularity measurement and the pairwise interaction of nodes modelled as a bargaining problem. The outcome of this process is the fair split up of dwelling time as a network resource and the selection of which content objects to exchange in order to maximise the nodes’ payoff. The framework is generally intended to be used as a capstone for investigation of content dissemination properties and various content exchange strategies in a DTN, a topic addressed in this paper and experiments conducted to validate the function and correctness of the proposed framework. 

  • 220. Bauer, K.
    et al.
    Boreli, R.
    Carlsson, N.
    Chen, Z.
    Francillon, A.
    Freudiger, J.
    Friedman, A.
    Gambs, S.
    Haddadi, H.
    Hecker, A.
    Hui, P.
    Kaafar, M. -A
    Köpf, B.
    Mahanti, A.
    Önen, M.
    Papadimitratos, Panagiotis
    KTH, School of Electrical Engineering (EES), Communication Networks.
    Ries, S.
    Salamatian, K.
    Schneider, F.
    Shikfa, A.
    Shue, C.
    Strufe, T.
    Uhlig, S.
    Uzun, E.
    Xie, G.
    Welcome message from the PADE chairs2013In: Welcome message from the PADE chairs  (Editorial), IEEE Computer Society, 2013, p. lxi-lxiiConference paper (Other academic)
  • 221.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Harper, B.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Judge, J.
    Location Aware Mobile Computing1997In: Proceedings of ICT '97, IEEE , 1997, p. 1319-1324Conference paper (Refereed)
  • 222.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Smith, Mark T.
    Location Augmented Mobile Computing and Communication Systems1997In: Proc. Third Asia-Pacific Conference on Communications (APCC’97), 1997, p. 827-831Conference paper (Refereed)
  • 223.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Smith, Mark T.
    Location Based Personal Mobile Computing and Communication1998In: Proceedings of 9th IEEE Workshop on Local and Metropolitan Area Networks, IEEE , 1998, p. 23-24Conference paper (Refereed)
  • 224.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Smith, Mark T.
    Using location and environment awareness in mobile communications1997In: Proceedings of the International Conference on Information, Communications and Signal Processing, ICICS, IEEE , 1997, p. 1781-1785Conference paper (Refereed)
    Abstract [en]

    We are investigating the use of badge based wearable computers to create highly mobile location and environment aware systems. When coupled to intelligent servers the badges provide an unparalleled platform for human centred information environments. This paper describes the architecture of the badge, its distributed computing environment, and presents initial results of application development trials conducted by a class of telecommunications students at KTH.

  • 225.
    Becker, Kalle
    KTH, Superseded Departments, Teleinformatics.
    Calling your mailbox1998Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This paper presents how the company for whom this work was preformed should act to add an email reading feature to their platform. It also includes an evaluation of the usability of such a system (called Popeye).

    A field trial with Popeye was carried out, and also analyzed to understand both how users want to use this kind of service and also to evaluate speech technology in such applications.

    This paper also briefly describes the platform and why it is a good idea to use Microsoft Transaction Server (MTS) together with COM when building large systems in a Windows NT environment.

    Two different approaches to creation of this feature are discussed and the design of a COM interface was done. This interface will let voice mail vendors connect with the system and this will minimize the hardware that the telecom operators will have to buy and maintain.

    The solution I prefer is the one that means that the company has to build a complete new product. This solution will be harder to implement but I think that it will give the company the most benefits in the end. My conclusions can be read in chapter 5.

  • 226. Beckman, C.
    et al.
    Borg, J.
    Johansson, J.
    Tecsor, Irina
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Design Considerations for the EISCAT_3D Phased Array Antenna2014In: 8th European Conference on Antennas and Propagation, EuCAP 2014, IEEE , 2014, p. 1700-1704Conference paper (Refereed)
    Abstract [en]

    This paper presents a background and an overview of the initial design considerations for phased array antenna being designed for the New Generation multi-static, incoherent-scatter radar station - EISCAT-3D - in Northern Scandinavia. Its anticipated electrical, mechanical and environmental design requirements are given both by the physics as well as by the extreme climate in the subarctic region of northern Scandinavia.

  • 227.
    Beermann, Mikael
    KTH, Superseded Departments, Teleinformatics.
    Implementation of the Mobile Floating Agent Technique1996Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The computer has undergone an explosive development since they first arrived. Today nearly everybody uses computers more or less frequently. The trend is now that everyone has a little computer connected to others in a network. The computing power has become more decentralized, and therefore the need for communication has increased. Another thing that has changed the pattern is that the computers has become so small that it is no longer any problem to move them as long as one does not care about the network support, but of course one would like to have both the mobility and the network support.

    In my master thesis project I have implemented and evaluated parts of a new approach for dealing with the problems with mobility. This approach is called the mobile floating agent technique, and was developed by George Y. Liu at Ericsson Radio Systems AB, Kista. The main idea behind this is to have floating agents in the network, i.e. software entities that are virtually floating around in the network, arranging files and resources for the mobile user so that he can connect to a server in his neighbourhood, instead of connecting to his own server far away.

    I have implemented a simple file system testbed that uses the floating agent technique for caching purposes. There are two reasons for doing this implementation. The reason is for evaluation of the caching features, and the second reason is to have a platform to implement more advanced agent functions on.

    The design of the system has been done in an object oriented style, and the implementation has been done in C++.The system consists of two parts. One part is the client software, which has been implemented in another project, but modified by me, and runs on aPC with the Windows95 OS. The other part is the network part of the system, i.e. the part of the system that is not running in the client, is made for running on an UNIX station. The network part of the system consists of two parts itself. There are mobile floating agent managers, that manages the whole system, and agents, that serves the mobile clients, and communicates with both the client software and the mobile floating agent managers.

    In the evaluation part of the project I have compared the delay acquired when accessing a file in a remote network with and without an agent. I finally came to the conclusion that the gain won with the use of caches in the agents is maybe not as large that one should use caching as the primary object of the agents.

  • 228.
    Beermann, Mikael
    KTH, Superseded Departments, Teleinformatics.
    Implementation of the Mobile Floating Agent Technique1996Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The computer has undergone an explosive development since they first arrived. Today nearly everybody uses computers more or less frequently. The trend is now that everyone has a little computer connected to others in a network. The computing power has become more decentralized, and therefore the need for communication has increased. Another thing that has changed the pattern is that the computers has become so small that it is no longer any problem to move them as long as one does not care about the network support, but of course one would like to have both the mobility and the network support.

    In my master thesis project I have implemented and evaluated parts of a new approach for dealing with the problems with mobility. This approach is called the mobile floating agent technique, and was developed by George Y. Liu at Ericsson Radio Systems AB, Kista. The main idea behind this is to have floating agents in the network, i.e. software entities that are virtually floating around in the network, arranging files and resources for the mobile user so that he can connect to a server in his neighbourhood, instead of connecting to his own server far away.  I have implemented a simple file system testbed that uses the floating agent technique for caching purposes. There are two reasons for doing this implementation. The reason is for evaluation of the caching features, and the second reason is to have a platform to implement more advanced agent functions on.

    The design of the system has been done in an object oriented style, and the implementation has been done in C++.The system consists of two parts. One part is the client software, which has been implemented in another project, but modified by me, and runs on aPC with the Windows95 OS. The other part is the network part of the system, i.e. the part of the system that is not running in the client, is made for running on an UNIX station. The network part of the system consists of two parts itself. There are mobile floating agent managers, that manages the whole system, and agents, that serves the mobile clients, and communicates with both the client software and the mobile floating agent managers.

    In the evaluation part of the project I have compared the delay acquired when accessing a file in a remote network with and without an agent. I finally came to the conclusion that the gain won with the use of caches in the agents is maybe not as large that one should use caching as the primary object of the agents.

  • 229. Behrooz, Alireza
    et al.
    Devlic, Alisa
    A Context-Aware Privacy Policy Language for Controlling Access to Context Information of Mobile Users2012In: Security and Privacy in Mobile Information and Communication Systems: Third International ICST Conference, MobiSec 2011, Aalborg, Denmark, May 17-19, 2011, Revised Selected Papers, Springer Berlin Heidelberg, 2012, p. 25-39Conference paper (Refereed)
    Abstract [en]

    This paper introduces a Context-aware Privacy Policy Language (CPPL) that enables mobile users to control who can access their context information, at what detail, and in which situation by specifying their context-aware privacy rules. Context-aware privacy rules map a set of privacy rules to one or more user's situations, in which these rules are valid. Each time a user's situation changes, a list of valid rules is updated, leaving only a subset of the specified rules to be evaluated by a privacy framework upon arrival of a context query. In the existing context-dependent privacy policy languages a user's context is used as an additional condition parameter in a privacy rule, thus all the specified privacy rules have to be evaluated when a request to access a user's context arrives. Keeping the number of rules that need to be evaluated small is important because evaluation of a large number of privacy rules can potentially increase the response time to a context query. CPPL also enables rules to be defined based on a user's social relationship with a context requestor, which reduces the number of rules that need to be defined by a user and that consequently need to be evaluated by a privacy mechanism. This paper shows that when compared to the existing context-dependent privacy policy languages, this number of rules (that are encoded using CPPL) decreases with an increasing number of user-defined situations and requestors that are represented by a small number of social relationship groups.

  • 230.
    Bektesevic, Edin
    KTH, Superseded Departments, Teleinformatics.
    Embedded Linux for Purposes of Internet Appliances: (a.k.a. ‘The Wanderer Project’)1999Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As the Internet continues to grow, now new Internet appliances are being marketed. At the same time, Linux is gradually becoming a competitive choice for desktop, server and embedded applications. How do these two facts relate to each other? What should be the position of Linux in Internet appliances, and how interesting is Linux? Where are the Internet appliances really positioned in terms of their needs for an operating system? How is Linux implemented in embedded applications?

    These are just some of the questions posed during this MSc. Project that this report aims to answer. In addition, we will examine how Linux is used in embedded applications and what it provides in terms of achieving their goals. Also, we will take a look at the compression methods that can be used for system size reduction and analyze their costs.

    The report will show that Linux is a competitive alternative for devices like WebPAD, that it leaves space for further time and cost efficient improvements, and that Internet appliances can get most of the benefits of Linux during its further evolution relatively cheaply.

  • 231.
    Bellagamba, Elisa
    et al.
    Ericsson Research.
    Andersson, Loa
    Ericsson AB.
    Sköldström, Pontus
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Network Systems Laboratory (NS Lab).
    Ward, Dave
    Drake, John
    Configuration of Pro-Active Operations, Administration, and Maintenance (OAM) Functions for MPLS-based Transport Networks using LSP Ping2013Other (Other (popular science, discussion, etc.))
  • 232. Bellagamba, Elisa
    et al.
    Kempf, James
    Sköldström, Pontus
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Telecommunication Systems Laboratory, TSLab (closed 2012-01-01).
    Link Failure Detection and Traffic Redirection in an Openflow Network2010Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Failure detection and traffic redirection are implemented in an OpenFlow switch. Link failure detection packets, such as Bidirectional Forwarding Detection (BFD) packets, are periodically sent out on links to peer OpenFlow switches, such as via the Multi-protocol Label Switching (MPLS) Transport Profile (MPLS-TP). Link failure detection packets are received from the peer OpenFlow switches on the links, and monitored. A link failure is detected if no incoming link failure detection packets are received on a link for a predetermined interval. In the event of a link failure, traffic is redirected from the failed link to a backup link by altering entries on a flow table of the OpenFlow switch.

  • 233.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain.
    Barcelo, Jaume
    Universidad Carlos III, Madrid, Spain.
    Staehle, Dirk
    University of Wurzburg, Wurzburg, Germany.
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Oliver, Miquel
    Universitat Pompeu Fabra, Barcelona, Spain.
    On the performance of packet aggregation in IEEE 802.11ac MU-MIMO WLANs2012In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 16, no 10, p. 1588-1591Article in journal (Refereed)
    Abstract [en]

    Multi-user spatial multiplexing combined with packet aggregation can significantly increase the performance of Wireless Local Area Networks (WLANs). In this letter, we present and evaluate a simple technique to perform packet aggregation in IEEE 802.11ac MU-MIMO (Multi-user Multiple Input Multiple Output) WLANs. Results show that in non-saturation conditions both the number of active stations (STAs) and the queue size have a significant impact on the system performance. If the number of STAs is excessively high, the heterogeneity of destinations in the packets contained in the queue makes it difficult to take full advantage of packet aggregation. This effect can be alleviated by increasing the queue size, which increases the chances of scheduling a large number of packets at each transmission, hence improving the system throughput at the cost of a higher delay. © 1997-2012 IEEE.

  • 234.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain.
    Belyaev, Evgeny
    Tampere University of Technology, Finland.
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Performance evaluation of IEEE 802.11p-enabled vehicular video surveillance system2014In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 18, no 4, p. 708-711Article in journal (Refereed)
    Abstract [en]

    Prospective IEEE 802.11p-based vehicular surveillance system, where video from the vehicle on-board camera is transmitted to the management center, is considered. Multi-hop transmission from the vehicle to the nearest roadside unit and then-via other roadside units-to the gateway is addressed. In this letter we assess the feasibility of such system by analyzing the video end-to-end distortion for a target vehicle, located several hops away from the gateway, when it is alone or there are also other vehicles transmitting video. We demonstrate the importance of dynamic adaptation of the video bit rate of each vehicle depending on the number and positions of the participating vehicles. © 2014 IEEE.

  • 235.
    Bellalta, Boris
    et al.
    Department of Information Technologies and Communications, Universitat Pompeu Fabra, Barcelona, Spain.
    Faridi, Azadeh
    Department of Information Technologies and Communications, Universitat Pompeu Fabra, Barcelona, Spain.
    Staehle, Dirk
    Department of Computer Science, University of Würzburg, Würzburg, Germany.
    Barcelo, Jaume
    Department of Information Technologies and Communications, Universitat Pompeu Fabra, Barcelona, Spain.
    Vinel, Alexey
    Department of Electronics and Communication Engineering, Tampere University of Technology, Tampere, Finland.
    Oliver, Miquel
    Department of Information Technologies and Communications, Universitat Pompeu Fabra, Barcelona, Spain.
    Performance analysis of CSMA/CA protocols with multi-packet transmission2013In: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 57, no 14, p. 2675-2688Article in journal (Refereed)
    Abstract [en]

    Wireless objects equipped with multiple antennas are able to simultaneously transmit multiple packets by exploiting the channel's spatial dimensions. In this paper, we study the benefits of such Multiple Packet Transmission (MPT) approach, when it is used in combination with a Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol for fully interconnected networks, addressing the interactions between the two mechanisms and showing the performance gains that can be achieved. To this end, a very simple Media Access Control (MAC) protocol that captures the fundamental properties and tradeoffs of a CSMA/CA channel access protocol supporting MPT is introduced. Using this protocol as a reference, a new analytical model is presented for the case of non-saturated traffic sources with finite buffer space. Simulation results show that the analytical model is able to accurately characterize the steady-state behavior of the reference protocol for different number of antennas and different traffic loads, providing a useful tool for understanding the performance gains achieved by MAC protocols supporting MPT. © 2013 Elsevier B.V. All rights reserved.

  • 236.
    Bellalta, Boris
    et al.
    Pompeu Fabra University, Barcelona, Spain.
    Vinel, Alexey
    Chatzimisios, Periklis
    Alexander Technological Educational Institute of Thessaloniki, Thessaloniki, Greece.
    Bruno, Raffaele
    Istituto di Informatica e Telematica (IIT) / Consiglio Nazionale delle Ricerche (CNR), Pisa, Italy.
    Wang, Chonggang
    InterDigital Communications, King of Prussia, PA, USA.
    Research advances and standardization activities in WLANs2014In: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 39, p. 1-2Article in journal (Refereed)
  • 237.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain.
    Vinel, AlexeyDepartment of Communications Engineering, Tampere University of Technology, Finland.Jonsson, MagnusHalmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).Barcelo, JaumeUniversitat Pompeu Fabra, Barcelona, Spain.Maslennikov, RomanUniversity of Nizhny Novgorod, Russia.Chatzimisios, PeriklisAlexander Technological Educational Institute of Thessaloniki Sindos, Greece.Malone, DavidNational University of Ireland, Maynooth, Ireland.
    Multiple Access Communications: 5th International Workshop, MACOM 2012, Maynooth, Ireland, November 19-20, 2012. Proceedings2012Conference proceedings (editor) (Refereed)
    Abstract [en]

    The proceedings contain 18 papers. The topics discussed include: network coding as a WiMAX link reliability mechanism; initialization procedure of wireless network coding with hierarchical decode and forward strategy in random connectivity networks; a coded DHA FH OFDMA system with a noncoherent ML detector under multitone jamming; analysis of inter-RSU beaconing interference in VANETs; survey of energy efficient tracking and localization techniques in buildings using optical and wireless communication media; network coding as a WiMAX link reliability mechanism: an experimental demonstration; spectrum sensing with USRP-E110; power control for wireless networks with a limited number of channels; a measurement study for predicting throughput from LQI and RSSI; reality considerations when designing a TDMA-FDMA based link-layer for real-time WSN; and wireless groupcast routing with palette of transmission methods.

  • 238.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain .
    Vinel, Alexey
    Department of Communications Engineering, Tampere University of Technology, Tampere, Finland.
    Oliver, Miquel
    Universitat Pompeu Fabra, Barcelona, Spain .
    An upper-bound queueing model for Multi-rate Downlink SDMA systems2010In: 2010 International Congress on Ultra Modern Telecommunications and Control Systems and Workshops, ICUMT 2010, 2010, p. 1212-1217Conference paper (Refereed)
  • 239.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain.
    Zocca, Alessandro
    Eindhoven University of Technology, Eindhoven, The Netherlands.
    Cano, Cristina
    Hamilton Institute, Maynooth, Ireland.
    Checco, Alessandro
    Hamilton Institute, Maynooth, Ireland.
    Barcelo, Jaume
    Universitat Pompeu Fabra, Barcelona, Spain.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Throughput Analysis in CSMA/CA Networks Using Continuous Time Markov Networks: A Tutorial2014In: Wireless Networking for Moving Objects / [ed] Ivan Ganchev, Marília Curado, Andreas Kassler, Cham: Springer, 2014, p. 115-133Chapter in book (Refereed)
    Abstract [en]

    This book chapter introduces the use of Continuous Time Markov Networks (CTMN) to analytically capture the operation of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) networks. It is of tutorial nature, and it aims to be an introduction on this topic, providing a clear and easy-to-follow description. To illustrate how CTMN can be used, we introduce a set of representative and cutting-edge scenarios, such as Vehicular Ad-hoc Networks (VANETs), Power Line Communication networks and multiple overlapping Wireless Local Area Networks (WLANs). For each scenario, we describe the specific CTMN, obtain its stationary distribution and compute the throughput achieved by each node in the network. Taking the per-node throughput as reference, we discuss how the complex interactions between nodes using CSMA/CA have an impact on system performance.

  • 240.
    Beltramelli, Luca
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Österberg, Patrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Modelling of EnergyConsumption in IEEE 802.11.ah Networks for M2M Traffic2016In: Proceedings of SNCNW 2016: The 12th Swedish National Computer Networking Workshop, 2016, p. 38-41Conference paper (Refereed)
    Abstract [en]

    IEEE 802.11ah is a sub-1 GHz standard designed to meet the requirements of future machine-to-machine (M2M) communications. The standard should be able to support use cases for the M2M communications with thousands of stations capable of generating both periodic and aperiodic traffic for a single access point. In some cases, like environmental and agricultural monitoring. the nodes are typically powered by battery or through energy harvesting. For this application it is important for the communication to be energy efficient. IEEE 802.11ah introduces new energy saving mechanisms and a novel channel access mechanism to achieve this objective even for networks with a large nodes number. This work proposes a mathematical model to compute the energy consumption of an IEEE 802.11ah network.

  • 241.
    Beltramelli, Luca
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Österberg, Patrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Jennehag, Ulf
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Gidlund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Hybrid MAC Mechanism for Energy Efficient Communication in IEEE 802.11ah2017In: Proceedings of the 2017 IEEE International Conference on Industrial Technology (ICIT), IEEE, 2017, p. 1295-1300, article id 7915550Conference paper (Refereed)
    Abstract [en]

    Many applications for machine-to-machine (M2M) communications are characterized by large numbers of devices with sporadic transmissions and subjected to low energy budgets. This work addresses the importance of energy consumption by proposing a new Medium Access Control (MAC) mechanism for improving the energy efficiency of IEEE 802.11ah, a standard targeting M2M communication. We propose to use the features of IEEE 802.11ah MAC to realize a hybrid contention-reservation mechanism for the transmission of uplink traffic. In the proposed mechanism, any device with a buffered packet will first notify the Access Point (AP) during a contention phase before being given a reserved timeslot for the data transmission. We develop a mathematical model to analyse the energy consumption ofthe proposed mechanism and of IEEE 802.11ah. The results show that for a monitoring scenario, the proposed contention reservation mechanism reduces the energy consumption for a successful uplink data transmission by up to 55%.

  • 242. Beltran, M
    et al.
    Deng, L
    Pang, Xiaodan
    RISE ACREO AB.
    Zhang, X
    Arlunno, V
    Zhao, Y
    Yu, X
    Llorente, R
    Liu, D
    Tafur Monroy, I
    Single- and Multiband OFDM Photonic Wireless Links in the 75-110 GHz Band EmployingOptical Combs2012In: IEEE Photonics Journal, Vol. 4, no 5, p. 2027-2036Article in journal (Refereed)
  • 243. Beltrán, Marta
    et al.
    Deng, Lei
    Pang, Xiaodan
    RISE ACREO AB.
    Zhang, Xu
    Arlunno, Valeria
    Zhao, Ying
    Yu, Xianbin
    Llorente, Roberto
    Liu, Deming
    Tafur Monroy, Idelfonso
    38.2-Gb/s Optical-Wireless Transmission in 75-110 GHz Based on Electrical OFDM with Optical Comb Expansion2012In: Optical Fiber Communication Conference, 2012Conference paper (Refereed)
  • 244.
    Belyaev, Evgeny
    et al.
    Department of Signal Processing, Tampere University of Technology, Tampere, Finland.
    Molchanov, Pavlo
    Department of Signal Processing, Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Department of Electronics and Communication Engineering, Tampere University of Technology, Tampere, Finland.
    Koucheryavy, Yevgeni
    Department of Electronics and Communication Engineering, Tampere University of Technology, Tampere, Finland.
    The Use of Automotive Radars in Video-Based Overtaking Assistance Applications2013In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 14, no 3, p. 1035-1042, article id 649464Article in journal (Refereed)
    Abstract [en]

    Overtaking on rural roads may cause severe accidents when oncoming traffic is detected by a driver too late, or its speed is underestimated. Recently proposed cooperative overtaking assistance systems are based on real-time video transmission, where a video stream captured with a camera installed at the windshield of a vehicle is compressed, broadcast through the wireless channel, and displayed to the drivers of vehicles driving behind. In such a system, it is of ultimate importance to deliver video information about the opposite lane with low end-to-end latency and good visual quality. In this paper, we propose reallocating the wireless channel resources in favor of the part of the captured video frame containing the image of the oncoming vehicle. To achieve this goal, we apply automotive radar for oncoming vehicle detection, and we use the image of this vehicle as a region-of-interest (ROI) for the video rate control. We present the theoretical framework, which describes the basics of such an approach and can serve as a useful guideline for the future practical implementation of the overtaking assistance systems. The benefits of our proposal are demonstrated in relation to the practical scenario of H.264/Advance Video Coding (AVC), IEEE 802.11p/Wireless Access for Vehicular Environments (WAVE) intervehicle communication standards, and currently used automotive radars.

  • 245.
    Belyaev, Evgeny
    et al.
    Technical University of Denmark, Lyngby, Denmark.
    Moreschini, Sergio
    Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Uncoordinated multi-user video streaming in VANETs using Skype2017In: 2017 IEEE 22nd International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), 2017Conference paper (Refereed)
    Abstract [en]

    Real-time video delivery in Vehicle-to-Infrastructure (V2I) scenario enables a variety of multimedia vehicular services. We conduct experiments with Dedicated Short Range Communications (DSRC) transceivers located in the mutual proximity and exchanging Skype video calls traffic. We demonstrate that the lack of coordination between the users both at the application as well as Medium Access Control (MAC) layers results in problems with quality of service provisioning even for the setup without vehicular mobility. © Copyright 2017 IEEE

  • 246.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Poster: Target Packet Loss Selection for Inter-Packet Loss Protection for Video Streaming Over VANETs2014In: 2014 IEEE Vehicular Networking Conference (VNC) / [ed] Falko Dressler, Onur Altintas, Suman Banerjee, Björn Scheuermann & David Eckhoff, Piscataway, N.J.: IEEE Press, 2014, p. 197-198Conference paper (Refereed)
    Abstract [en]

    This work is dedicated to a live video streaming in vehicular networks where the application-based inter-packet forward error correction is used for the packet loss protection. A practical way to apply such a protection at the video encoder side for the unknown channel loss rate is proposed. Experimental results which demonstrate the performance for the proposed approach for a scalable extension of the H.264/AVC standard (H.264/SVC) and for the non-standardized video codec based on three-dimensional discrete wavelet transform (3-D DWT) are provided.

  • 247.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tampere, Finland .
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Tampere University of Technology, Tampere, Finland.
    Egiazarian, Karen
    Tampere University of Technology, Tampere, Finland.
    Koucheryavy, Yevgeni
    Tampere University of Technology, Tampere, Finland.
    Power Control in See-Through Overtaking Assistance System2013In: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 17, no 3, p. 612-615, article id 6423758Article in journal (Refereed)
    Abstract [en]

    In recently proposed cooperative overtaking assistance systems a video stream captured by a windshield-mounted camera in a vehicle is compressed and broadcast to the vehicle driving behind it, where it is displayed to the driver. It has been shown that this system can provide robust operation if video codec channel adaptation is undertaken by exploiting information from the cooperative awareness messages about any forthcoming increases in the multiple access channel load. In this letter we demonstrate the gains achievable in system performance when the video transmitter power control is also used. © 1997-2012 IEEE.

  • 248.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tempere, Finland.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Sjöberg, Katrin
    Volvo GTT, Göteborg, Sweden.
    Live video streaming in IEEE 802.11p vehicular networks: Demonstration of an automotive surveillance application2014In: Computer Communications Workshops (INFOCOM WKSHPS), 2014 IEEE Conference on, Piscataway, United States: IEEE Press, 2014, p. 131-132Conference paper (Refereed)
    Abstract [en]

    Prospective IEEE 802.11p-enabled automotive video applications are identified. Preliminary experimental results of inter-vehicular live video streaming for surveillance applications are presented. A test-bed for the demonstration of the achievable visual quality under different channel conditions is described.

  • 249.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Surak, Adam
    Tampere University of Technology, Tampere, Finland.
    Gabbouj, Moncef
    Tampere University of Technology, Tampere, Finland.
    Jonsson, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Egiazarian, Karen
    Tampere University of Technology, Tampere, Finland.
    Robust vehicle-to-infrastructure video transmission for road surveillance applications2015In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 64, no 7, p. 2991-3003Article in journal (Refereed)
    Abstract [en]

    IEEE 802.11p vehicle-to-vehicle and vehicle-to-infrastructure communication technology is currently an emerging research topic in both industry and academia. Respective spectrum allocation of 10 MHz channels in the 5.9 GHz band for USA and Europe allows considering inter-vehicle transmission of a live video information as a basis, which enables a new class of safety and infotainment automotive applications such as road video surveillance. This paper is first of its kind where such a video transmission system is developed and experimentally validated. We propose a low-complexity unequal packet loss protection and rate control algorithms for a scalable video coding based on the three-dimensional discrete wavelet transform. We show that in comparison with a scalable extension of the H.264/AVC standard the new codec is less sensitive to packet losses, has less computational complexity and provides comparable performance in case of unequal packet loss protection. It is specially designed to cope with severe channel fading typical for dynamic vehicular environments and has a low complexity, making it a feasible solution for real-time automotive surveillance applications. Extensive measurements obtained in realistic city traffic scenarios demonstrate that good visual quality and continuous playback is possible when the moving vehicle is in the radius of 600 meters from the roadside unit. ©2014 IEEE

  • 250.
    Ben Slimane, Slimane
    KTH, Superseded Departments, Signals, Sensors and Systems.
    A low complexity antenna diversity receiver for OFDM based systems2001In: IEEE International Conference on Communications, 2001, p. 1147-1151Conference paper (Refereed)
    Abstract [en]

    A low complexity antenna diversity architecture with a new combining technique suitable for orthogonal frequency division (OFDM) based systems is introduced in this paper. For a two branch antenna diversity, this structure requires only one FFT at the receiver and allows optimum maximum ratio combining. For systems with a higher number of antennas, the number of required FFTs when using such technique is reduced by half as compared to the conventional case where a different FFT is used for each receive antenna. As a result a considerable reduction in processing complexity is obtained especially for systems with high number of subcarriers. This method can also be seen as a way of increasing the number of antennas in OFDM transceivers without any major complexity increase. Thus, a considerable increase in diversity gain can be achieved

2345678 201 - 250 of 3328
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