Publications
1.
Kühlmorgen, S.; Lu, H.; Festag, A.; Kenney, J.; Gemsheim, S.; Fettweis, G.
Evaluation of Congestion-Enabled Forwarding With Mixed Data Traffic in Vehicular Communications Journal Article
In: IEEE Transactions on Intelligent Transportation Systems, vol. 21, no. 1, pp. 233-247, 2019.
Abstract | Links | BibTeX | Tags: ad hoc networking, Cooperative ITS, Intelligent Transport Systems, V2X communication
@article{Kuehlmorgen:IEEETransITS:2020,
title = {Evaluation of Congestion-Enabled Forwarding With Mixed Data Traffic in Vehicular Communications},
author = {S. Kühlmorgen and H. Lu and A. Festag and J. Kenney and S. Gemsheim and G. Fettweis},
url = {https://ieeexplore.ieee.org/document/8617699},
doi = {10.1109/TITS.2018.2890619},
year = {2019},
date = {2019-01-17},
urldate = {2019-01-17},
journal = {IEEE Transactions on Intelligent Transportation Systems},
volume = {21},
number = {1},
pages = {233-247},
abstract = {ITS-G5 is a communication system for vehicle-to-everything communication for road safety and traffic efficiency applications. On the lower layers, it is based on IEEE 802.11 standard and uses a simple ad hoc mode with a random medium access control scheme. Ad hoc networking is realized by a geographical routing scheme that provides single- and multi-hop communication over ITS-G5 links for periodic and event-driven broadcast messages. Specifically, contention-based forwarding (CBF) allows for efficient and reliable multi-hop packet transport by overhearing and timer-based transmission control. To cope with the channel congestion, decentralized congestion control (DCC) adjusts the message rate and ensures that the network load keeps below a predefined threshold of the bandwidth. To enforce a node's message rate, a `` Gatekeeper'' above the MAC and beneath CBF is added. Under high network load, this Gatekeeper introduces an additional queuing delay seen by CBF, which can cause its overhearing function to fail. This contribution studies multi-hop forwarding in the context of DCC with the Gatekeeper and LIMERIC as a rate adaptation algorithm. We propose a congestion-enabled forwarding scheme that, in comparison to existing approaches considering DCC and forwarding separately, restores the efficient operation of CBF, and improves the communication performance in terms of reliability and latency for mixed data traffic composed of single- and multi-hop packets with different priorities. The simulations show the performance improvements in a freeway scenario. An analysis assesses the boundary conditions for CBF and the Gatekeeper. Moreover, the analysis corroborates the simulation.},
keywords = {ad hoc networking, Cooperative ITS, Intelligent Transport Systems, V2X communication},
pubstate = {published},
tppubtype = {article}
}
ITS-G5 is a communication system for vehicle-to-everything communication for road safety and traffic efficiency applications. On the lower layers, it is based on IEEE 802.11 standard and uses a simple ad hoc mode with a random medium access control scheme. Ad hoc networking is realized by a geographical routing scheme that provides single- and multi-hop communication over ITS-G5 links for periodic and event-driven broadcast messages. Specifically, contention-based forwarding (CBF) allows for efficient and reliable multi-hop packet transport by overhearing and timer-based transmission control. To cope with the channel congestion, decentralized congestion control (DCC) adjusts the message rate and ensures that the network load keeps below a predefined threshold of the bandwidth. To enforce a node's message rate, a `` Gatekeeper'' above the MAC and beneath CBF is added. Under high network load, this Gatekeeper introduces an additional queuing delay seen by CBF, which can cause its overhearing function to fail. This contribution studies multi-hop forwarding in the context of DCC with the Gatekeeper and LIMERIC as a rate adaptation algorithm. We propose a congestion-enabled forwarding scheme that, in comparison to existing approaches considering DCC and forwarding separately, restores the efficient operation of CBF, and improves the communication performance in terms of reliability and latency for mixed data traffic composed of single- and multi-hop packets with different priorities. The simulations show the performance improvements in a freeway scenario. An analysis assesses the boundary conditions for CBF and the Gatekeeper. Moreover, the analysis corroborates the simulation.
2.
Kühlmorgen, S.; Festag, A.; Fettweis, G.
Impact of Decentralized Congestion Control on Contention-based Forwarding in VANETs Proceedings Article
In: IEEE International Symposium on A World of Wireless, Mobile and Multimedia Networks (WoWMoM), Coimbra, Portugal, 2016.
Abstract | Links | BibTeX | Tags: ad hoc networking, V2X communication
@inproceedings{Kuehlmorgen:WoWMoM:2016,
title = {Impact of Decentralized Congestion Control on Contention-based Forwarding in VANETs},
author = {S. Kühlmorgen and A. Festag and G. Fettweis},
url = {https://ieeexplore.ieee.org/document/7523572},
doi = {10.1109/WoWMoM.2016.7523572},
year = {2016},
date = {2016-06-21},
urldate = {2016-07-28},
booktitle = {IEEE International Symposium on A World of Wireless, Mobile and Multimedia Networks (WoWMoM)},
address = {Coimbra, Portugal},
abstract = {Vehicular ad hoc networks based on IEEE 802.11 OCB suffer from channel congestion, which will be critical for safety applications when the channel becomes saturated. Therefore, decentralized congestion control (DCC) is needed that keeps the channel load under a pre-defined threshold. In the European system for vehicular communication, a DCC-gatekeeper has been inserted into the protocol stack that reduces the data traffic generated or forwarded by the vehicle. This DCC-gatekeeper affects the functionality of the contention-based forwarding (CBF) and degrades its performance. In this paper we evaluate the performance of CBF under congestion-free and saturated channel conditions for several protocol variants: DCF, EDCA and DCC-gatekeeper. The results show that the standard DCC-gatekeeper hampers the functionality of CBF even for small node densities. We enhance the DCC-gatekeeper-based approach to overcome this issue and evaluate the protocol variants in terms of reliability, latency and channel load in a freeway scenario with realistic trace-based mobility.},
keywords = {ad hoc networking, V2X communication},
pubstate = {published},
tppubtype = {inproceedings}
}
Vehicular ad hoc networks based on IEEE 802.11 OCB suffer from channel congestion, which will be critical for safety applications when the channel becomes saturated. Therefore, decentralized congestion control (DCC) is needed that keeps the channel load under a pre-defined threshold. In the European system for vehicular communication, a DCC-gatekeeper has been inserted into the protocol stack that reduces the data traffic generated or forwarded by the vehicle. This DCC-gatekeeper affects the functionality of the contention-based forwarding (CBF) and degrades its performance. In this paper we evaluate the performance of CBF under congestion-free and saturated channel conditions for several protocol variants: DCF, EDCA and DCC-gatekeeper. The results show that the standard DCC-gatekeeper hampers the functionality of CBF even for small node densities. We enhance the DCC-gatekeeper-based approach to overcome this issue and evaluate the protocol variants in terms of reliability, latency and channel load in a freeway scenario with realistic trace-based mobility.
3.
Llatser, I.; Kühlmorgen, S.; Festag, A.; Fettweis, G.
Greedy Algorithms for Information Dissemination within Groups of Autonomuous Vehicles Proceedings Article
In: IEEE Intelligent Vehicles Symposium (IV), Seoul, Korea, 2015.
Abstract | Links | BibTeX | Tags: ad hoc networking, V2X communication, vehicle automation
@inproceedings{Kuehlmorgen:IV:2015,
title = {Greedy Algorithms for Information Dissemination within Groups of Autonomuous Vehicles},
author = {I. Llatser and S. Kühlmorgen and A. Festag and G. Fettweis},
url = {https://ieeexplore.ieee.org/document/7225899},
doi = {10.1109/IVS.2015.7225899},
year = {2015},
date = {2015-06-28},
urldate = {2015-08-27},
booktitle = {IEEE Intelligent Vehicles Symposium (IV)},
address = {Seoul, Korea},
abstract = {Cooperation and information exchange will allow autonomous vehicles to increase their sensing range and maneuver coordinately, thereby greatly enhancing their safety and efficiency. The combination of autonomous driving and vehicular communications will enable Cooperative Autonomous Driving Systems (C-ADS) with stringent requirements. We present two new multi-hop forwarding algorithms specially suited to the dissemination of information in C-ADS: (i) Greedy Broadcast Forwarding, aimed to the distribution of packets within a geographical area, and (ii) Greedy Multicast Forwarding, which delivers packets only to the members of a vehicle group. A performance comparison of the proposed schemes with the broadcast forwarding algorithms defined in the ETSI GeoNetworking standard shows that Greedy Broadcast Forwarding achieves the highest reliability, while Greedy Multicast Forwarding yields the lowest traffic overhead in the considered scenario. These results indicate that the proposed forwarding algorithms are promising candidates to enable multi-hop communications in future C-ADS.},
keywords = {ad hoc networking, V2X communication, vehicle automation},
pubstate = {published},
tppubtype = {inproceedings}
}
Cooperation and information exchange will allow autonomous vehicles to increase their sensing range and maneuver coordinately, thereby greatly enhancing their safety and efficiency. The combination of autonomous driving and vehicular communications will enable Cooperative Autonomous Driving Systems (C-ADS) with stringent requirements. We present two new multi-hop forwarding algorithms specially suited to the dissemination of information in C-ADS: (i) Greedy Broadcast Forwarding, aimed to the distribution of packets within a geographical area, and (ii) Greedy Multicast Forwarding, which delivers packets only to the members of a vehicle group. A performance comparison of the proposed schemes with the broadcast forwarding algorithms defined in the ETSI GeoNetworking standard shows that Greedy Broadcast Forwarding achieves the highest reliability, while Greedy Multicast Forwarding yields the lowest traffic overhead in the considered scenario. These results indicate that the proposed forwarding algorithms are promising candidates to enable multi-hop communications in future C-ADS.
4.
Kühlmorgen, S.; Llatser, I.; Festag, A.; Fettweis, G.
Performance Evaluation of ETSI GeoNetworking for Vehicular Ad hoc Networks Proceedings Article
In: IEEE Vehicular Technology Conference (VTC-Spring), Glasgow, UK, 2015.
Abstract | Links | BibTeX | Tags: ad hoc networking, V2X communication
@inproceedings{Kuehlmorgen:VTCSpring:2015,
title = {Performance Evaluation of ETSI GeoNetworking for Vehicular Ad hoc Networks},
author = {S. Kühlmorgen and I. Llatser and A. Festag and G. Fettweis},
url = {https://ieeexplore.ieee.org/document/7146003},
doi = {10.1109/VTCSpring.2015.7146003},
year = {2015},
date = {2015-05-11},
urldate = {2015-07-02},
booktitle = {IEEE Vehicular Technology Conference (VTC-Spring)},
address = {Glasgow, UK},
abstract = {The GeoNetworking protocol provides single-hop and multi-hop communication in vehicular ad hoc networks based on IEEE 802.11p/ITS-G5. It has been standardized by the ETSI Technical Committee ITS as part of its Release 1 set of specifications and is expected to be deployed in the next years. This paper presents a performance evaluation of the GeoNetworking protocol in its recently published version. Our study assesses the performance of the broadcast forwarding algorithms for multi-hop packet transport that are used to disseminate information in geographical areas for road safety and traffic efficiency applications. From the algorithms specification in the standard, we derive six variants with different combinations of protocol mechanisms with increasing complexity and assess their performance in terms of reliability, latency, and overhead. The algorithms are evaluated in a reference freeway scenario with bidirectional road traffic and a realistic trace-based mobility model with varying vehicle density. The obtained results indicate that the combination of contention-based and greedy forwarding shows the best overall performance; further functional improvements have a limited performance gain in the studied scenario.},
keywords = {ad hoc networking, V2X communication},
pubstate = {published},
tppubtype = {inproceedings}
}
The GeoNetworking protocol provides single-hop and multi-hop communication in vehicular ad hoc networks based on IEEE 802.11p/ITS-G5. It has been standardized by the ETSI Technical Committee ITS as part of its Release 1 set of specifications and is expected to be deployed in the next years. This paper presents a performance evaluation of the GeoNetworking protocol in its recently published version. Our study assesses the performance of the broadcast forwarding algorithms for multi-hop packet transport that are used to disseminate information in geographical areas for road safety and traffic efficiency applications. From the algorithms specification in the standard, we derive six variants with different combinations of protocol mechanisms with increasing complexity and assess their performance in terms of reliability, latency, and overhead. The algorithms are evaluated in a reference freeway scenario with bidirectional road traffic and a realistic trace-based mobility model with varying vehicle density. The obtained results indicate that the combination of contention-based and greedy forwarding shows the best overall performance; further functional improvements have a limited performance gain in the studied scenario.
5.
Festag, A.; Hartenstein, H.; Mittag, J.
Technologies - Communication: Wireless LAN-Based Vehicular Communication Book Section
In: Crolla, D.; Foster, D. E.; Kobayashi, T.; Vaughan, N. (Ed.): Encyclopedia of Automotive Engineering, pp. 3327-3340, John Wiley & Sons Ltd, Chichester, 2015, ISBN: ISBN: 978-0-470-97402-5.
Abstract | Links | BibTeX | Tags: ad hoc networking, V2X communication
@incollection{Festag:EncyclopediaAutoEngineering:2015,
title = {Technologies - Communication: Wireless LAN-Based Vehicular Communication},
author = {A. Festag and H. Hartenstein and J. Mittag},
editor = {D. Crolla and D. E. Foster and T. Kobayashi and N. Vaughan},
url = {https://www.wiley.com/en-gb/Encyclopedia+of+Automotive+Engineering-p-9780470974025},
doi = {10.1002/9781118354179.auto170},
isbn = {ISBN: 978-0-470-97402-5},
year = {2015},
date = {2015-02-01},
urldate = {2015-02-01},
booktitle = {Encyclopedia of Automotive Engineering},
pages = {3327-3340},
publisher = {John Wiley & Sons Ltd},
address = {Chichester},
abstract = {Wireless local area networking (WLAN)-based communication enables vehicles to exchange information that is beyond the vehicle's and the driver's direct perception. It has the potential to support various applications for road safety and traffic efficiency, such as road hazard warning and collision avoidance. As opposed to cellular mobile networks, WLAN-based vehicular communication does not require a central control or an operator; instead it uses a decentralized and self-organizing approach. This article introduces key requirements and basic characteristics of WLAN-based vehicular communication and outlines the system architecture. Furthermore, it gives an overview of the most important technology components for WLAN-based vehicular communication, covering radio and communication protocols, security and privacy, radio resource management, and congestion control. The article concludes with an overview about standardization and an outlook on the system deployment.},
keywords = {ad hoc networking, V2X communication},
pubstate = {published},
tppubtype = {incollection}
}
Wireless local area networking (WLAN)-based communication enables vehicles to exchange information that is beyond the vehicle's and the driver's direct perception. It has the potential to support various applications for road safety and traffic efficiency, such as road hazard warning and collision avoidance. As opposed to cellular mobile networks, WLAN-based vehicular communication does not require a central control or an operator; instead it uses a decentralized and self-organizing approach. This article introduces key requirements and basic characteristics of WLAN-based vehicular communication and outlines the system architecture. Furthermore, it gives an overview of the most important technology components for WLAN-based vehicular communication, covering radio and communication protocols, security and privacy, radio resource management, and congestion control. The article concludes with an overview about standardization and an outlook on the system deployment.