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  • 201. Baliosian, J.
    et al.
    Stadler, Rolf
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Decentralized configuration of neighboring cells for radio access networks2007Ingår i: 2007 IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks, WOWMOM, IEEE , 2007, s. 4351740-Konferensbidrag (Refereegranskat)
    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.

  • 202. Bang, I.
    et al.
    Kim, Su Min
    KTH, Skolan för elektro- och systemteknik (EES), Signalbehandling.
    Sung, D. K.
    Opportunistic user selection with adaptive jamming for secure communication in heterogeneous networks2015Ingår i: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, IEEE conference proceedings, 2015, s. 42-46Konferensbidrag (Refereegranskat)
    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.

  • 203. Bao, J.
    et al.
    Ma, Z.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap.
    Tsiftsis, T. A.
    Zhu, Z.
    Performance analysis of uplink sparse code multiple access with iterative multiuser receiver2017Ingår i: IEEE International Conference on Communications, Institute of Electrical and Electronics Engineers Inc. , 2017Konferensbidrag (Refereegranskat)
    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.

  • 204.
    Barac, Filip
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    Gidlund, Mikael
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    Zhang, Tingting
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    LPED: Channel Diagnostics in WSN Through Channel Coding and Symbol Error Statistics2014Ingår i: IEEE ISSNIP 2014 - 2014 IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing, Conference Proceedings, Singapore: IEEE Sensors Council, 2014, s. 1-6Konferensbidrag (Refereegranskat)
    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.

  • 205.
    Barac, Filip
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    Gidlund, Mikael
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem. ABB Corp Res, S-72178 Vasteras, Sweden.
    Zhang, Tingting
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    Scrutinizing Bit- and Symbol-Errors of IEEE 802.15.4 Communication in Industrial Environments2014Ingår i: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 63, nr 7, s. 1783-1794Artikel i tidskrift (Refereegranskat)
    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.

  • 206.
    Barac, Filip
    et al.
    Ericsson AB.
    Gidlund, Mikael
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    Zhang, Tingting
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem.
    Sisinni, Emiliano
    University of Brescia.
    Error Manifestation in Industrial WSN Communication and Guidelines for Countermeasures2017Ingår i: Wireless Sensor Systems for Extreme Environments: Space, Underwater, Underground and Industrial / [ed] H. F. Rashvand and A. Abedi, John Wiley & Sons, 2017Kapitel i bok, del av antologi (Refereegranskat)
  • 207.
    Barac, Filip
    et al.
    Mid Sweden University.
    Yu, Kan
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Gidlund, Mikael
    ABB, Corporate Research.
    Åkerberg, Johan
    ABB, Corporate Research.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Towards Reliable and Lightweight Communication in Industrial Wireless Sensor Networks2012Konferensbidrag (Refereegranskat)
    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.

  • 208. 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
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Xing, L
    You, J
    Subjective and Objective Visual Quality Assessment in the Context of stereoscopic 3DTV2013Ingår i: 3DTV System with Depth-Image-Based Rendering / [ed] Yu, L., Tanimoto, M., and Zhu, C., Springer, 2013, s. 413-437Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 209.
    Barkowsky, M
    et al.
    University of Nantes, France.
    Masala, E
    Politecnico di Torino, Italy.
    Van Wallendael, G
    Ghent University - iMinds, Belgium.
    Brunnström, Kjell
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informations- och kommunikationssystem. 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.2015Ingår i: IEICE transactions on communications, ISSN 0916-8516, E-ISSN 1745-1345, Vol. E98-B, nr 1, s. 2-11Artikel i tidskrift (Refereegranskat)
    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.

  • 210. Baroffio, L.
    et al.
    Canclini, A.
    Cesana, M.
    Redondi, A.
    Tagliasacchi, M.
    Dán, György
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Eriksson, Emil
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Fodor, Viktoria
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Ascenso, J.
    Monteiro, P.
    Demo: Enabling image analysis tasks in visual sensor networks2014Ingår i: Proceedings of the 8th ACM/IEEE International Conference on Distributed Smart Cameras, ICDSC 2014, Association for Computing Machinery (ACM), 2014, s. a46-Konferensbidrag (Refereegranskat)
    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.

  • 211.
    Barrera Diaz, Carlos Alberto
    et al.
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    Oscarsson, Jan
    Högskolan i Skövde, Institutionen för ingenjörsvetenskap. Högskolan i Skövde, Forskningscentrum för Virtuella system.
    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 Plant2017Ingår i: 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, , s. 12Konferensbidrag (Refereegranskat)
    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.

  • 212.
    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 Station2009Ingår i: 2009 4th International Symposium on Wireless and Pervasive Computing, ISWPC 2009, IEEE, 2009, artikel-id 4800602Konferensbidrag (Refereegranskat)
    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.

  • 213.
    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 station2009Ingår i: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, artikel-id 821846Artikel i tidskrift (Refereegranskat)
    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.

  • 214.
    Bastani, Saeed
    et al.
    The University of Sydney.
    Landfeldt, Björn
    Lund University.
    Rohner, Christian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Gunningberg, Per
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    A social node model for realising information dissemination strategies in delay tolerant networks2012Ingår i: Proceedings of the 15th ACM international conference on Modeling, analysis and simulation of wireless and mobile systems, New york: ACM Press, 2012, s. 79-88Konferensbidrag (Refereegranskat)
    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. 

  • 215. 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, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Ries, S.
    Salamatian, K.
    Schneider, F.
    Shikfa, A.
    Shue, C.
    Strufe, T.
    Uhlig, S.
    Uzun, E.
    Xie, G.
    Welcome message from the PADE chairs2013Ingår i: Welcome message from the PADE chairs  (Editorial), IEEE Computer Society, 2013, s. lxi-lxiiKonferensbidrag (Övrigt vetenskapligt)
  • 216.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Harper, B.
    Maguire Jr., Gerald Q.
    KTH, Tidigare Institutioner, Teleinformatik.
    Judge, J.
    Location Aware Mobile Computing1997Ingår i: Proceedings of ICT '97, IEEE , 1997, s. 1319-1324Konferensbidrag (Refereegranskat)
  • 217.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Maguire Jr., Gerald Q.
    KTH, Tidigare Institutioner, Teleinformatik.
    Smith, Mark T.
    Location Augmented Mobile Computing and Communication Systems1997Ingår i: Proc. Third Asia-Pacific Conference on Communications (APCC’97), 1997, s. 827-831Konferensbidrag (Refereegranskat)
  • 218.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Maguire Jr., Gerald Q.
    KTH, Tidigare Institutioner, Teleinformatik.
    Smith, Mark T.
    Location Based Personal Mobile Computing and Communication1998Ingår i: Proceedings of 9th IEEE Workshop on Local and Metropolitan Area Networks, IEEE , 1998, s. 23-24Konferensbidrag (Refereegranskat)
  • 219.
    Beadle, H.W.P.
    et al.
    Wollongong University.
    Maguire Jr., Gerald Q.
    KTH, Tidigare Institutioner, Teleinformatik.
    Smith, Mark T.
    Using location and environment awareness in mobile communications1997Ingår i: Proceedings of the International Conference on Information, Communications and Signal Processing, ICICS, IEEE , 1997, s. 1781-1785Konferensbidrag (Refereegranskat)
    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.

  • 220.
    Becker, Kalle
    KTH, Tidigare Institutioner, Teleinformatik.
    Calling your mailbox1998Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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.

  • 221. Beckman, C.
    et al.
    Borg, J.
    Johansson, J.
    Tecsor, Irina
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Design Considerations for the EISCAT_3D Phased Array Antenna2014Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, IEEE , 2014, s. 1700-1704Konferensbidrag (Refereegranskat)
    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.

  • 222.
    Beermann, Mikael
    KTH, Tidigare Institutioner, Teleinformatik.
    Implementation of the Mobile Floating Agent Technique1996Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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.

  • 223.
    Beermann, Mikael
    KTH, Tidigare Institutioner, Teleinformatik.
    Implementation of the Mobile Floating Agent Technique1996Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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.

  • 224. Behrooz, Alireza
    et al.
    Devlic, Alisa
    A Context-Aware Privacy Policy Language for Controlling Access to Context Information of Mobile Users2012Ingår i: 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, s. 25-39Konferensbidrag (Refereegranskat)
    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.

  • 225.
    Bektesevic, Edin
    KTH, Tidigare Institutioner, Teleinformatik.
    Embedded Linux for Purposes of Internet Appliances: (a.k.a. ‘The Wanderer Project’)1999Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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.

  • 226.
    Bellagamba, Elisa
    et al.
    Ericsson Research.
    Andersson, Loa
    Ericsson AB.
    Sköldström, Pontus
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, 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 Ping2013Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 227. Bellagamba, Elisa
    et al.
    Kempf, James
    Sköldström, Pontus
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikation: Infrastruktur och tjänster (Stängd 20120101), Telekommunikationssystem, TSLab (stängd 2012-01-01).
    Link Failure Detection and Traffic Redirection in an Openflow Network2010Patent (Övrig (populärvetenskap, debatt, mm))
    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.

  • 228.
    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 WLANs2012Ingår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 16, nr 10, s. 1588-1591Artikel i tidskrift (Refereegranskat)
    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.

  • 229.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain.
    Belyaev, Evgeny
    Tampere University of Technology, Finland.
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Performance evaluation of IEEE 802.11p-enabled vehicular video surveillance system2014Ingår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 18, nr 4, s. 708-711Artikel i tidskrift (Refereegranskat)
    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.

  • 230.
    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 transmission2013Ingår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 57, nr 14, s. 2675-2688Artikel i tidskrift (Refereegranskat)
    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.

  • 231.
    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 WLANs2014Ingår i: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 39, s. 1-2Artikel i tidskrift (Refereegranskat)
  • 232.
    Bellalta, Boris
    et al.
    Universitat Pompeu Fabra, Barcelona, Spain.
    Vinel, AlexeyDepartment of Communications Engineering, Tampere University of Technology, Finland.Jonsson, MagnusHögskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (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. Proceedings2012Proceedings (redaktörskap) (Refereegranskat)
    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.

  • 233.
    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 systems2010Ingår i: 2010 International Congress on Ultra Modern Telecommunications and Control Systems and Workshops, ICUMT 2010, 2010, s. 1212-1217Konferensbidrag (Refereegranskat)
  • 234.
    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
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Throughput Analysis in CSMA/CA Networks Using Continuous Time Markov Networks: A Tutorial2014Ingår i: Wireless Networking for Moving Objects / [ed] Ivan Ganchev, Marília Curado, Andreas Kassler, Cham: Springer, 2014, s. 115-133Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 235.
    Beltramelli, Luca
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Österberg, Patrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Jennehag, Ulf
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Gidlund, Mikael
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för informationssystem och -teknologi.
    Hybrid MAC Mechanism for Energy Efficient Communication in IEEE 802.11ah2017Ingår i: Proceedings of the 2017 IEEE International Conference on Industrial Technology (ICIT), IEEE, 2017, s. 1295-1300, artikel-id 7915550Konferensbidrag (Refereegranskat)
    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%.

  • 236. 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 Combs2012Ingår i: IEEE Photonics Journal, Vol. 4, nr 5, s. 2027-2036Artikel i tidskrift (Refereegranskat)
  • 237. 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 Expansion2012Ingår i: Optical Fiber Communication Conference, 2012Konferensbidrag (Refereegranskat)
  • 238.
    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
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (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 Applications2013Ingår i: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 14, nr 3, s. 1035-1042, artikel-id 649464Artikel i tidskrift (Refereegranskat)
    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.

  • 239.
    Belyaev, Evgeny
    et al.
    Technical University of Denmark, Lyngby, Denmark.
    Moreschini, Sergio
    Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Uncoordinated multi-user video streaming in VANETs using Skype2017Ingår i: 2017 IEEE 22nd International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), 2017Konferensbidrag (Refereegranskat)
    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

  • 240.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Poster: Target Packet Loss Selection for Inter-Packet Loss Protection for Video Streaming Over VANETs2014Ingår i: 2014 IEEE Vehicular Networking Conference (VNC) / [ed] Falko Dressler, Onur Altintas, Suman Banerjee, Björn Scheuermann & David Eckhoff, Piscataway, N.J.: IEEE Press, 2014, s. 197-198Konferensbidrag (Refereegranskat)
    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.

  • 241.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tampere, Finland .
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (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 System2013Ingår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 17, nr 3, s. 612-615, artikel-id 6423758Artikel i tidskrift (Refereegranskat)
    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.

  • 242.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tempere, Finland.
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Sjöberg, Katrin
    Volvo GTT, Göteborg, Sweden.
    Live video streaming in IEEE 802.11p vehicular networks: Demonstration of an automotive surveillance application2014Ingår i: Computer Communications Workshops (INFOCOM WKSHPS), 2014 IEEE Conference on, Piscataway, United States: IEEE Press, 2014, s. 131-132Konferensbidrag (Refereegranskat)
    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.

  • 243.
    Belyaev, Evgeny
    et al.
    Tampere University of Technology, Tampere, Finland.
    Vinel, Alexey
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Surak, Adam
    Tampere University of Technology, Tampere, Finland.
    Gabbouj, Moncef
    Tampere University of Technology, Tampere, Finland.
    Jonsson, Magnus
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Egiazarian, Karen
    Tampere University of Technology, Tampere, Finland.
    Robust vehicle-to-infrastructure video transmission for road surveillance applications2015Ingår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 64, nr 7, s. 2991-3003Artikel i tidskrift (Refereegranskat)
    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

  • 244.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    A low complexity antenna diversity receiver for OFDM based systems2001Ingår i: IEEE International Conference on Communications, 2001, s. 1147-1151Konferensbidrag (Refereegranskat)
    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

  • 245.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Bounds on the Distribution of a Sum of Independent Lognormal Random Variables2001Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 49, nr 6, s. 975-978Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The distribution function of a sum of lognormal random variables (RVs) appears in several communication problems. Approximations are usually used for such distribution as no closed form nor bounds exist. Bounds can be very useful in assessing the performance of any given system. In this letter, we derive upper and lower bounds on the distribution function of a sum of independent lognormal RVs. These bounds are given in a closed form and can be used in studying the performance of cellular radio and broadcasting systems.

  • 246.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Channel estimation for HIPERLAN/2 with transmitter diversity2002Konferensbidrag (Refereegranskat)
  • 247.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Channel estimation for HIPERLAN/2 with transmitter diversity2002Ingår i: 2002 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-5, CONFERENCE PROCEEDINGS, 2002, s. 26-30Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we propose a channel estimation technique for OFDM based systems, such as HIPERLAN/2 and IEEE 802.11a, with transmitter diversity. The proposed technique estimates all channel frequency responses, corresponding to each transmitter and receiver antenna pair, required for space-time processing In this OFDM based system. This technique is able to extract the channel state Information for two transmitter antennas using the same preamble as defined in the standard of HIPERLAN/2. The feasibility of this channel estimation method Is made possible by exploiting the structure of the OFDM modulation scheme. The results showed that the accuracy provided by this proposed method is comparable to that obtained when a single transmitter antenna is used.

  • 248.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Channel estimation for OFDM based systems with transmitter diversity2002Ingår i: 2002 IEEE International Conference on Systems, Man and Cybernetics,, 2002, s. 397-402Konferensbidrag (Refereegranskat)
  • 249.
    Ben Slimane, Slimane
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Peak-to-average power ratio reduction of OFDM signals using broadband pulse shaping2002Ingår i: IEEE 56TH VEHICULAR TECHNOLOGY CONFERENCE, VTC FALL 2002, VOLS 1-4, PROCEEDINGS, 2002, s. 889-893Konferensbidrag (Refereegranskat)
    Abstract [en]

    Orthogonal Frequency Division Multiplexing (OFDM) techniques allow the transmission of high data rates over broadband radio channels subject to multipath fading without the need for powerful channel equalization. However, they are very sensitive to nonlinear effects due to the high Peak-to-Average Power Ratio (PAPR) owned by the transmitted signal. This paper proposes an efficient technique for reducing the PAPR of OFDM signals. The proposed technique is very effective and flexible. The method avoids the use of extra Inverse Fast Fourier Transformations (IFFTs) as was done in some previously published techniques but instead is based on a proper selection of the time waveforms of the different sub-carriers of the OFDM modulation scheme. Thus, its implementation complexity is much low in comparison to the previous published methods. A closed form relation between the maximum PAPR and the used pulse shaping waveform is derived. The obtained results show that with broadband pulse shaping, the PAPR of OFDM modulated signals can be made very close to that of single carrier signals. The improved statistics of the PAPR in the transmitted signal is demonstrated through numerical results for some sets of time waveforms. The significant improvement in PAPR given by the present technique permits to reduce the complexity and cost of the transmitter significantly. In that, pulse shaping can be used not only to shape the spectrum of the transmitted signal but also to reduce its PAPR.

  • 250.
    Ben Slimane, Slimane
    et al.
    KTH, Tidigare Institutioner, Signaler, sensorer och system.
    Janssen, G.J.M.
    Delft University.
    Power optimization of M-PSK cochannel signals for a narrowband multiuser detector2001Ingår i: IEEE Pacific RIM Conference on Communications, Computers, and Signal Processing - Proceedings, 2001, s. 247-250Konferensbidrag (Refereegranskat)
    Abstract [en]

    An analytical method is presented to determine the optimum received power values for multiple cochannel multilevel phase-shift-keying (M-PSK) modulated signals. The aim is to achieve equal symbol error probability (SEP) for each of the signals when applying a narrowband multiuser detector based on successive cancellations. Power relations based on two approximations are derived and used to compute the average SEP for the different cochannel signals. The derived power relations are also compared against optimum power relations obtained through computer simulations

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