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Sjöberg, Katrin
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Publications (10 of 22) Show all publications
Abbas, T., Sjöberg, K., Kåredal, J. & Tufvesson, F. (2015). A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations. International Journal of Antennas and Propagation, Article ID 190607.
Open this publication in new window or tab >>A Measurement Based Shadow Fading Model for Vehicle-to-Vehicle Network Simulations
2015 (English)In: International Journal of Antennas and Propagation, ISSN 1687-5869, E-ISSN 1687-5877, article id 190607Article in journal (Refereed) Published
Abstract [en]

The vehicle-to-vehicle (V2V) propagation channel has significant implications on the design and performance of novel communication protocols for vehicular ad hoc networks (VANETs). Extensive research efforts have been made to develop V2V channel models to be implemented in advanced VANET system simulators for performance evaluation. The impact of shadowing caused by other vehicles has, however, largely been neglected in most of the models, as well as in the system simulations. In this paper we present a shadow fading model targeting system simulations based on real measurements performed in urban and highway scenarios. The measurement data is separated into three categories, line-of-sight (LOS), obstructed line-of-sight (OLOS) by vehicles, and non-line-of-sight due to buildings, with the help of video information recorded during the measurements. It is observed that vehicles obstructing the LOS induce an additional average attenuation of about 10 dB in the received signal power. An approach to incorporate the LOS/OLOS model into existing VANET simulators is also provided. Finally, system level VANET simulation results are presented, showing the difference between the LOS/OLOS model and a channel model based on Nakagami-m fading.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2015
National Category
Telecommunications Vehicle Engineering Signal Processing Embedded Systems
Identifiers
urn:nbn:se:hh:diva-35443 (URN)10.1155/2015/190607 (DOI)000357217500001 ()2-s2.0-84934301469 (Scopus ID)
Available from: 2017-11-22 Created: 2017-11-22 Last updated: 2017-11-22Bibliographically approved
Belyaev, E., Vinel, A., Jonsson, M. & Sjöberg, K. (2014). Live video streaming in IEEE 802.11p vehicular networks: Demonstration of an automotive surveillance application. In: Computer Communications Workshops (INFOCOM WKSHPS), 2014 IEEE Conference on: . Paper presented at 2014 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), April 27 2014-May 2 2014, Toronto, Canada (pp. 131-132). Piscataway, United States: IEEE Press
Open this publication in new window or tab >>Live video streaming in IEEE 802.11p vehicular networks: Demonstration of an automotive surveillance application
2014 (English)In: Computer Communications Workshops (INFOCOM WKSHPS), 2014 IEEE Conference on, Piscataway, United States: IEEE Press, 2014, p. 131-132Conference paper, Published 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.

Place, publisher, year, edition, pages
Piscataway, United States: IEEE Press, 2014
Series
IEEE Conference on Computer Communications Workshops, ISSN 2159-4228
National Category
Communication Systems Telecommunications
Identifiers
urn:nbn:se:hh:diva-27384 (URN)10.1109/INFCOMW.2014.6849190 (DOI)000343582700032 ()2-s2.0-84904488841 (Scopus ID)978-1-4799-3088-3 (ISBN)
Conference
2014 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS), April 27 2014-May 2 2014, Toronto, Canada
Available from: 2015-01-04 Created: 2015-01-04 Last updated: 2018-03-22Bibliographically approved
Lidström, K., Sjöberg, K., Holmberg, U., Andersson, J., Bergh, F., Bjäde, M. & Mak, S. (2012). A modular CACC system integration and design. IEEE transactions on intelligent transportation systems (Print), 13(3), 1050-1061
Open this publication in new window or tab >>A modular CACC system integration and design
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2012 (English)In: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 13, no 3, p. 1050-1061Article in journal (Refereed) Published
Abstract [en]

This paper describes the Halmstad University entry in the Grand Cooperative Driving Challenge, which is a competition in vehicle platooning. Cooperative platooning has the potential to improve traffic flow by mitigating shock wave effects, which otherwise may occur in dense traffic. A longitudinal controller that uses information exchanged via wireless communication with other cooperative vehicles to achieve string-stable platooning is developed. The controller is integrated into a production vehicle, together with a positioning system, communication system, and human–machine interface (HMI). A highly modular system architecture enabled rapid development and testing of the various subsystems. In the competition, which took place in May 2011 on a closed-off highway in The Netherlands, the Halmstad University team finished second among nine competing teams.

Place, publisher, year, edition, pages
Piscataway: IEEE Press, 2012
Keywords
Cooperative adaptive cruise control, grand cooperative driving challenge, platooning
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:hh:diva-19506 (URN)10.1109/TITS.2012.2204877 (DOI)000312805000007 ()2-s2.0-84863773935 (Scopus ID)
Available from: 2012-09-07 Created: 2012-09-07 Last updated: 2018-03-22Bibliographically approved
Mecklenbräuker, C., Bernadó, L., Klemp, O., Kwoczek, A., Paier, A., Schack, M., . . . Zemen, T. (2012). Vehicle-to-Vehicle Communications. In: Roberto Verdone & Alberto Zanella (Ed.), Pervasive Mobile and Ambient Wireless Communications: Cost Action 2100 (pp. 577-608). London: Springer London
Open this publication in new window or tab >>Vehicle-to-Vehicle Communications
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2012 (English)In: Pervasive Mobile and Ambient Wireless Communications: Cost Action 2100 / [ed] Roberto Verdone & Alberto Zanella, London: Springer London, 2012, p. 577-608Chapter in book (Other academic)
Abstract [en]

This chapter discusses major results and conclusions from Special Interest Group C bringing together various aspects of mobile to mobile communication from all working groups. Vehicle-to-vehicle communication scenarios are emphasized. Traffic telematics applications are currently under intense research and development for making transportation safer, more efficient, and cleaner. Communication systems which provide “always on” connectivity at data rates between 1 and 10 Mb/s to highly mobile surface traffic (cars and trains) are urgently required for developing traffic telematics applications and services. Currently much attention is given to advanced active safety, but the application area also ranges to improved navigation mechanisms and infotainment services. mobile to mobile communications need to be reliable and trusted: Drivers in cars which are equipped with vehicle to vehicle communications need to rely on the accuracy and timeliness of the exchanged data. Automotive manufacturers, road authorities, broadcast companies, and telecom providers are the key players in the value chain for such future systems. These communication systems provide an extended information horizon to warn the driver or the vehicular systems of potentially dangerous situations in an early phase.

Place, publisher, year, edition, pages
London: Springer London, 2012
Series
Signals and Communication Technology, ISSN 1860-4862
Keywords
vehicular communications
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hh:diva-19702 (URN)10.1007/978-1-4471-2315-6_14 (DOI)978-1-4471-2315-6 (ISBN)978-1-4471-2314-9 (ISBN)
Available from: 2012-09-21 Created: 2012-09-21 Last updated: 2018-03-22Bibliographically approved
Sjöberg, K., Uhlemann, E. & Ström, E. G. (2011). Delay and interference comparison of CSMA and self-organizing TDMA when used in VANETs. In: IEEE (Ed.), IWCMC 2011: the 7th International Wireless Communications & Mobile Computing Conference, Istanbul, Turkey, July 4-8, 2011. Paper presented at 7th International Wireless Communications and Mobile Computing Conference (IWCMC) Istanbul, 4-8 July, 2011 (pp. 1488-1793). New York, NY: IEEE Press
Open this publication in new window or tab >>Delay and interference comparison of CSMA and self-organizing TDMA when used in VANETs
2011 (English)In: IWCMC 2011: the 7th International Wireless Communications & Mobile Computing Conference, Istanbul, Turkey, July 4-8, 2011 / [ed] IEEE, New York, NY: IEEE Press, 2011, p. 1488-1793Conference paper, Oral presentation only (Refereed)
Abstract [en]

IEEE 802.11p is the proposed wireless technology for communication between vehicles in a vehicular ad hoc network (VANET) aiming to increase road traffic safety. In a VANET, the network topology is constantly changing, which requires distributed self-organizing medium access control (MAC) algorithms, but more importantly the number of participating nodes cannot be restricted. This means that MAC algorithms with good scalability are needed, which can fulfill the concurrent requirements on delay and reliability from road traffic safety applications. The MAC method of IEEE 802.11p is a carrier sense multiple access (CSMA) scheme, which scales badly in terms of providing timely channel access for a high number of participating nodes. We therefore propose using another MAC method: selforganizing time division multiple access (STDMA) with which all nodes achieve timely channel access regardless of the number of participating nodes. We evaluate the performance of the two MAC methods in terms of the MAC-to-MAC delay, a measure which captures both the reliability and the delay of the delivered data traffic for a varying number of vehicles. The numerical results reveal that STDMA can support almost error-free transmission with a 100 ms deadline to all receivers within 100 m, while CSMA suffers from packet errors. Moreover, for all considered cases, STDMA offers better reliability than CSMA.

Place, publisher, year, edition, pages
New York, NY: IEEE Press, 2011
Keywords
MAC, VANET, CSMA, STDMA, IEEE 802.11p, V2V
National Category
Telecommunications
Identifiers
urn:nbn:se:hh:diva-16109 (URN)10.1109/IWCMC.2011.5982758 (DOI)000300570200243 ()2-s2.0-80052488880 (Scopus ID)978-1-4244-9539-9 (ISBN)978-1-4244-9537-5 (ISBN)
Conference
7th International Wireless Communications and Mobile Computing Conference (IWCMC) Istanbul, 4-8 July, 2011
Note

©2011 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

Available from: 2012-10-04 Created: 2011-09-04 Last updated: 2018-03-22Bibliographically approved
Sjöberg, K., Uhlemann, E. & Ström, E. G. (2011). How severe is the hidden terminal problem in VANETs when using CSMA and STDMA?. In: IEEE (Ed.), IEEE Vehicular Technology Conference (VTC Fall). Paper presented at IEEE Vehicular Technology Conference, 5-8 Sept., San Francisco, CA, USA, 2011 (pp. 1-5). Piscataway, N.J.: IEEE conference proceedings
Open this publication in new window or tab >>How severe is the hidden terminal problem in VANETs when using CSMA and STDMA?
2011 (English)In: IEEE Vehicular Technology Conference (VTC Fall) / [ed] IEEE, Piscataway, N.J.: IEEE conference proceedings, 2011, p. 1-5Conference paper, Published paper (Refereed)
Abstract [en]

The hidden terminal problem is often said to be the major limiting performance factor in vehicular ad hoc networks. In this article we propose a definition of the hidden terminal problem suitable for broadcast transmissions and proceed with a case study to find how the packet reception probability is affected by the presence of hidden terminals. Two different medium access control methods; carrier sense multiple access (CSMA) from IEEE 802.11p and self-organizing time division multiple access (STDMA), are subject of investigation through computer simulations of a highway scenario with a Nakagami fading channel model. The results reveal that the presence of hidden terminals does not significantly affect the performance of the two MAC protocols. STDMA shows a higher packet reception probability for all settings due to the synchronized packet transmissions.

Place, publisher, year, edition, pages
Piscataway, N.J.: IEEE conference proceedings, 2011
Series
Vehicular Technology Conference, ISSN 1090-3038 ; 2011
Keywords
hidden terminal, VANET, vehicular communications, STDMA, CSMA
National Category
Communication Systems
Identifiers
urn:nbn:se:hh:diva-16701 (URN)10.1109/VETECF.2011.6093256 (DOI)000298891500444 ()2-s2.0-83755180831 (Scopus ID)978-1-4244-8328-0 (ISBN)
Conference
IEEE Vehicular Technology Conference, 5-8 Sept., San Francisco, CA, USA, 2011
Note

©2011 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

Available from: 2012-01-10 Created: 2011-12-13 Last updated: 2018-03-22Bibliographically approved
Sjöberg, K., Karedal, J., Moe, M., Kristiansen, Ø., Søråsen, R., Uhlemann, E., . . . Ström, E. (2010). Measuring and using the RSSI of IEEE 802.11p. In: : . Paper presented at 17th World Congress on Intelligent Transport Systems (ITS), Busan, Korea, October 25-29, 2010.
Open this publication in new window or tab >>Measuring and using the RSSI of IEEE 802.11p
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2010 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The scalability of intelligent transport systems (ITS) applications is difficult to test in a field operational test (FOT) due to the high number of ITS equipped vehicles required. Therefore, computer simulations for evaluating different wireless communication technologies for ITS different applications can serve as a complement. In this paper we present results from lab measurements conducted on the CVIS hardware platform equipped with the upcoming standard IEEE 802.11p. We have measured the packet error rate versus the signal-to-noise ratio (SNR) for different packet lengths. This lab measurement is the first step towards an outdoor measurement campaign which also considers interference. The outdoor measurements will then be fed into a computer simulator together with a realistic channel model for evaluating the scalability of VANETs in a highway scenario.

Keywords
IEEE 802.11p, VANET, RSSI
National Category
Telecommunications
Identifiers
urn:nbn:se:hh:diva-14185 (URN)2-s2.0-84953931908 (Scopus ID)
Conference
17th World Congress on Intelligent Transport Systems (ITS), Busan, Korea, October 25-29, 2010
Available from: 2011-01-25 Created: 2011-01-24 Last updated: 2018-09-05Bibliographically approved
Sjöberg-Bilstrup, K., Uhlemann, E. & Ström, E. G. (2010). Scalability issues of the MAC methods STDMA and CSMA of IEEE 802.11p when used in VANETs. In: 2010 IEEE International Conference on Communications Workshops (ICC). Paper presented at IEEE International Conference on Communications Workshops, Cape Town, South Africa, May 2010 (pp. 1-5). Cape Town, South Africa: IEEE Computer Society
Open this publication in new window or tab >>Scalability issues of the MAC methods STDMA and CSMA of IEEE 802.11p when used in VANETs
2010 (English)In: 2010 IEEE International Conference on Communications Workshops (ICC), Cape Town, South Africa: IEEE Computer Society, 2010, p. 1-5Conference paper, Published paper (Refereed)
Abstract [en]

 

Position messages will be the foundation for many emerging traffic safety applications based on wireless communications. These messages contain information about the vehicle’s position, speed, direction, etc. and are broadcasted periodically by each vehicle. The upcoming IEEE 802.11p standard, intended for vehicle unpredictable behavior of its medium access control (MAC) scheme, which imply that traffic safety applications cannot be supported satisfactorily when the network load increases. We study the MAC mechanism within IEEE 802.11p being a carrier sense multiple access (CSMA) algorithm and compare it with a self-organizing time division multiple access (STDMA) scheme when used for broadcasting periodic position messages in a realistic highway scenario. We investigate their scalability in terms of the number of vehicles that the VANET can support using metrics such as channel access delay, probability of concurrent transmissions and interference distance. The results show that STDMA outperforms CSMA of 802.11p even when the network is not saturated.

 

Place, publisher, year, edition, pages
Cape Town, South Africa: IEEE Computer Society, 2010
Keywords
VANET, MAC, 802.11p, STDMA, CSMA, scalability
National Category
Telecommunications
Identifiers
urn:nbn:se:hh:diva-5250 (URN)10.1109/ICCW.2010.5503941 (DOI)2-s2.0-77954928450 (Scopus ID)978-1-4244-6824-9 (ISBN)
Conference
IEEE International Conference on Communications Workshops, Cape Town, South Africa, May 2010
Note

Copyright © 2010 IEEE. Reprinted from the ICC 2010 proceedings. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Halmstads's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.

Available from: 2010-08-29 Created: 2010-08-01 Last updated: 2018-03-23Bibliographically approved
Bilstrup, K., Uhlemann, E., Ström, E. G. & Bilstrup, U. (2009). On the ability of the 802.11p MAC method and STDMA to support real-time vehicle-to-vehicle communications. EURASIP Journal on Wireless Communications and Networking, 2009(902414), 1-14
Open this publication in new window or tab >>On the ability of the 802.11p MAC method and STDMA to support real-time vehicle-to-vehicle communications
2009 (English)In: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, Vol. 2009, no 902414, p. 1-14Article in journal (Refereed) Published
Abstract [en]

Traffic safety applications using vehicle-to-vehicle (V2V) communication is an emerging and promising area within the intelligent transportation systems (ITS) sphere. Many of these new applications require real-time communication with high reliability, meaning that packets must be successfully delivered before a certain deadline. Applications with early deadlines are expected to require direct V2V communications, and the only standard currently supporting this is the upcoming IEEE 802.11p, included in the wireless access in vehicular environment (WAVE) stack. To meet a real-time deadline, timely and predictable access to the channel is paramount. However, the medium access method used in 802.11p, carrier sense multiple access with collision avoidance (CSMA/CA), does not guarantee channel access before a finite deadline. In this paper, we analyze the communication requirements introduced by traffic safety applications, namely, low delay, reliable, real-time communications.We show by simulation of a simple, but realistic, highway scenario, that vehicles using CSMA/CA can experience unacceptable channel access delays and, therefore, 802.11p does not support real-time communications. In addition, we present a potential remedy for this problem, namely, the use of self-organizing time division multiple access (STDMA). The real-time properties of STDMA are investigated by means of the same highway simulation scenario, with promising results.

Place, publisher, year, edition, pages
New York: Hindawi Publishing Corporation, 2009
Keywords
Vehicle-to-vehicle communications, MAC, Real-time, Traffic safety, STDMA, IEEE 802.11p, Performance evaluation, Simulation
National Category
Telecommunications
Identifiers
urn:nbn:se:hh:diva-2460 (URN)10.1155/2009/902414 (DOI)000264966100001 ()2-s2.0-63749083930 (Scopus ID)2082/2862 (Local ID)2082/2862 (Archive number)2082/2862 (OAI)
Available from: 2009-04-16 Created: 2009-04-16 Last updated: 2018-03-23Bibliographically approved
Bilstrup, K., Uhlemann, E., Ström, E. G. & Bilstrup, U. (2009). On the ability of the IEEE 802.11p and STDMA to provide predictable channel access. In: Proceedings of the 16th World Congress on Intelligent Transport Systems (ITS). Paper presented at 16th World Congress on Intelligent Transport Systems (ITS), 21-25 september, Stockholm, Sweden, 2009 (pp. 10).
Open this publication in new window or tab >>On the ability of the IEEE 802.11p and STDMA to provide predictable channel access
2009 (English)In: Proceedings of the 16th World Congress on Intelligent Transport Systems (ITS), 2009, p. 10-Conference paper, Published paper (Refereed)
Abstract [en]

Emerging traffic safety applications requiring low delay communications will need vehicle ad-hoc networks. The only communication standard currently supporting this is IEEE 802.11p. However, 802.11p uses the medium access method CSMA/CA, which has a major drawback: unbounded worst case channel access delay. We therefore propose an algorithm already in commercial use in the shipping industry: STDMA. With STDMA, nodes always get predictable channel access regardless of the number of competing nodes and the maximum delay is deterministic. In this paper we elaborated with different parameter settings for the two protocols with the aim of improving performance without altering the standards.

 

Keywords
IEEE 802.11p, vehicla ad hoc, V2V, MAC, VANET, predictable channel access, vehicular communications, STDMA
National Category
Telecommunications
Identifiers
urn:nbn:se:hh:diva-4034 (URN)
Conference
16th World Congress on Intelligent Transport Systems (ITS), 21-25 september, Stockholm, Sweden, 2009
Available from: 2010-03-09 Created: 2010-03-05 Last updated: 2018-03-23Bibliographically approved
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