Publications
Hegde, A.; Festag, A.
Mode Switching Performance in Cellular-V2X Proceedings Article
In: IEEE Vehicular Networking Conference (VNC), virtual, 2020.
Abstract | Links | BibTeX | Tags: Cooperative ITS, Intelligent Transport Systems, performance, V2X communication
@inproceedings{Hegde:VNC:2020,
title = {Mode Switching Performance in Cellular-V2X},
author = {A. Hegde and A. Festag},
url = {https://ieeexplore.ieee.org/document/9318394},
doi = {10.1109/VNC51378.2020.9318394},
year = {2020},
date = {2020-12-16},
urldate = {2020-12-16},
booktitle = {IEEE Vehicular Networking Conference (VNC)},
address = {virtual},
abstract = {Cellular-V2X aims at supporting road safety and traffic management applications and introduces sidelink (PC5) as a new interface. These applications primarily rely on periodic broadcast of small-sized periodic messages and event-triggered notification messages. A key requirement of the applications is to facilitate uninterrupted exchange of messages among the vehicles irrespective of whether the vehicles are inside a base station coverage or not. In Cellular-V2X standardization, two resource allocation modes have been specified: when a vehicle is located inside the coverage of the cellular network, the corresponding base station manages the transmission resources for the direct message exchange. When a vehicle is outside of cellular coverage, it allocates its resources autonomously. The modes are also referred to as ``managed'' and ``unmanaged'' mode, or mode 3 and mode 4, respectively. In situations with imperfect cellular coverage by base stations, a vehicle needs to perform mode switching. The present work aims to understand the different phases of the mode switching procedure and to study the latency involved in each phase for both switching scenarios, mode 3 to 4 and vice versa. Considering a realistic road traffic scenario with a highway tunnel, we assess the impact of mode switch latency on the data transmission for a selected mode switch strategy.},
keywords = {Cooperative ITS, Intelligent Transport Systems, performance, V2X communication},
pubstate = {published},
tppubtype = {inproceedings}
}
Kühlmorgen, S.; Schmarger, P.; Festag, A.; Fettweis, G.
Simulation-based Evaluation of ETSI ITS-G5 and Cellular-VCS in a Real-World Traffic Scenario Proceedings Article
In: IEEE Vehicular Technology Conference (VTC-Fall), Chicago, IL, US, 2018.
Abstract | Links | BibTeX | Tags: Cooperative ITS, Intelligent Transport Systems, performance, simulation, V2X communication
@inproceedings{Kuelmorgen:VTCFall:2018,
title = {Simulation-based Evaluation of ETSI ITS-G5 and Cellular-VCS in a Real-World Traffic Scenario},
author = {S. Kühlmorgen and P. Schmarger and A. Festag and G. Fettweis},
url = {https://ieeexplore.ieee.org/document/8691011},
doi = {10.1109/VTCFall.2018.8691011},
year = {2018},
date = {2018-08-27},
booktitle = {IEEE Vehicular Technology Conference (VTC-Fall)},
address = {Chicago, IL, US},
abstract = {In recent years, two candidates for vehicular communications have evolved for the support of road safety and traffic efficiency applications. On the one hand, ad-hoc networks exist based on the ITS-G5/802.11p protocol stack, and on the other hand, there are cellular network infrastructures based on an extended LTE stack, which we refer to as Cellular-based Vehicular Communication Systems (Cellular-VCS). The most important extension of the classical LTE stack is a direct link among vehicles which is also called Device-to-Device (D2D) communication. Both approaches meet the requirements on vehicular communications but show technology-inherent mechanisms that result in different performances. ITS-G5 features a small latency at a small network load whereas Cellular-VCS promises a highly reliable packet transmission. One of the main difference of both approaches lies in the channel access which is random-based for ITS-G5 and centrally scheduled for Cellular-VCS. This contribution studies the performance of the two named technologies in a real-world road traffic scenario through comprehensive simulations. The simulation scenario makes use of real road traffic density measurements for modeling the mobility of the vehicles. Mixed network data traffic of periodically and event-based messages is generated through particular generation rules. The results prove that both technologies work stable at moderate road traffic conditions but have significant differences in the quantified communication parameters.},
keywords = {Cooperative ITS, Intelligent Transport Systems, performance, simulation, V2X communication},
pubstate = {published},
tppubtype = {inproceedings}
}
Kühlmorgen, S.; Festag, A.; Fettweis, G.
Evaluation of Multi-hop Packet Prioritization for Decentralized Congestion Control in VANETs Proceedings Article
In: IEEE Wireless Communications and Networking Conference (WCNC), San Francisco, CA, USA, 2017.
Abstract | Links | BibTeX | Tags: Cooperative ITS, Intelligent Transport Systems, performance, simulation, V2X communication
@inproceedings{Kuehlmorgen:WCNC:2017,
title = {Evaluation of Multi-hop Packet Prioritization for Decentralized Congestion Control in VANETs},
author = {S. Kühlmorgen and A. Festag and G. Fettweis},
url = {https://ieeexplore.ieee.org/document/7925899},
doi = {10.1109/WCNC.2017.7925899},
year = {2017},
date = {2017-03-19},
urldate = {2017-05-11},
booktitle = {IEEE Wireless Communications and Networking Conference (WCNC)},
address = {San Francisco, CA, USA},
abstract = {Decentralized congestion control (DCC) in ITS-G5 based vehicular ad hoc networks ensures that the requirements of safety and traffic efficiency applications are met even under high vehicle density and channel load conditions. In European standardization, a "gatekeeper" on top of the ITS-G5 MAC sub-layer is being considered that controls a node's packet rate as a function of the channel load. This paper studies the performance of the gatekeeper with packet prioritization and an adaptive linear control algorithm. The simulation results indicate that the gatekeeper with priority queuing (PQ) can effectively handle different packet priorities for multi-hop packets. Our gatekeeper-specific enhancements of the forwarding algorithm yield performance improvements in terms of reliability and latency compared to the plain DCC approach. Finally, we discuss the issue of packet starvation caused by the gatekeeper's PQ scheme that affects the performance of lower-priority packets.},
keywords = {Cooperative ITS, Intelligent Transport Systems, performance, simulation, V2X communication},
pubstate = {published},
tppubtype = {inproceedings}
}