Publications

@inproceedings{Hegde:SUMO:2021,

title = {Modeling Cellular Network Infrastructure in SUMO},

author = {A. Hegde and R. Stahl and S. Lobo and A. Festag},

url = {https://www.eclipse.org/sumo/2021/},

doi = {10.52825/scp.v2i.97},

year  = {2021},

date = {2021-09-01},

urldate = {2021-09-01},

booktitle = {SUMO User Conference},

address = {Virtual},

abstract = {Communication networks are becoming an increasingly important part of the mobility system. They allow traffic participants to be connected and to exchange information related to traffic and roads. The information exchange impacts the behavior of traffic participants, such as the selection of travel routes or their mobility dynamics. Considering infrastructure-based networks, the information exchange depends on the availability of the network infrastructure and the quality of the communication links. Specifically in urban areas, today's 4G and 5G networks deploy small cells of high capacity, which do not provide ubiquitous cellular coverage due to their small range, signal blocking, etc. Therefore, the accurate modeling of the network infrastructure and its integration in simulation scenarios in microscopic traffic simulation software is gaining relevance. Unlike traffic infrastructure, such as traffic lights, the simulation of a cellular network infrastructure is not natively supported in SUMO. Instead, the protocols, functions and entities of the communication system with the physical wireless transmission are modeled in a dedicated and specialized network simulator that is coupled with SUMO. The disadvantage of this approach is that the simulated SUMO entities, typically vehicles, are not aware which portions of the roads are covered by wireless cells and what quality the wireless communication links have.},

keywords = {Cooperative ITS, Intelligent Transport Systems, modeling, simulation, V2X communication},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Hegde:MSWIM:2020,

title = {Artery-C: An OMNeT++ Based Discrete Event Simulation Framework for Cellular V2X (Short version)},

author = {A. Hegde and A. Festag},

url = {https://dl.acm.org/doi/10.1145/3416010.3423240},

doi = {10.1145/3416010.3423240},

year  = {2020},

date = {2020-11-16},

urldate = {2020-11-16},

booktitle = {ACM 23rd Annual International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM)},

pages = {47–51},

address = {Alicante, Spain},

abstract = {Introduced with LTE Release 14, Cellular V2X enables device-to-device communication to support road safety and traffic efficiency applications. We present Artery-C, a simulation framework for the performance evaluation of Cellular V2X protocols and V2X applications. Our simulator relies on the simulation framework SimuLTE and substantially extends it by implementing control and user planes, a dedicated sidelink interface with specific focus on dynamic mode switching and some advanced features of 5G mobile networks, such as variable numerologies. Artery-C integrates seamlessly into the simulation framework Artery, which enables the simulation of standardized V2X messages at the facilities layer as well as the coupling to the mobility simulator SUMO. In order to demonstrate the capabilities of Artery-C, we evaluate V2X-based platooning as a representative use case and present results for mode 3, mode 4 and mode switching in a highway scenario.},

keywords = {Cooperative ITS, Intelligent Transport Systems, simulation, V2X communication},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{Hegde:IFAC:2019,

title = {Mode Switching Strategies in Cellular-V2X},

author = {A. Hegde and A. Festag},

url = {https://www.sciencedirect.com/science/article/pii/S2405896319303829},

doi = {10.1016/j.ifacol.2019.08.052},

year  = {2019},

date = {2019-07-03},

urldate = {2019-07-03},

booktitle = {10th IFAC Symposium on Intelligent Autonomous Vehicles},

address = {Gdansk, Poland},

abstract = {Cellular-V2X facilitates a direct communication among vehicles and with the roadside traffic infrastructure. It addresses use cases for safety and traffic efficiency, where data are disseminated in a vehicle's vicinity with short-latency constraints. Cellular-V2X provides two modes: when the vehicle is located in the coverage of the cellular network, the corresponding base station manages the transmission resources for the direct message exchange. In the out-of-coverage mode, the vehicle does not require cellular coverage and allocates its resources autonomously. Though the in-coverage mode is the preferred mode of operation, it is not always available. Due to the vehicle mobility and other reasons, a vehicle may need to dynamically switch between the two modes. Mode switching affects the communication quality since the vehicle cannot send and receive messages during the execution of the switching procedure. We propose three decision strategies for mode switching: forced, signal strength-based and load-based mode switching. We describe the mode switching decision by a cost function and derive individual functions for each of the proposed strategies. Decomposing the overall mode switching procedure into subsequent phases, we understand the different types of latencies incurred at every stage of mode switching.},

keywords = {Cooperative ITS, Intelligent Transport Systems, simulation, V2X communication},

pubstate = {published},

tppubtype = {inproceedings}

}

@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}

}

@inproceedings{Llatser:IV:2017,

title = {Simulation of Cooperative Automated Driving by Bidirectional Coupling of Vehicle and Network Simulators},

author = {I. Llatser and G. Jornod and A. Festag and D. Mansolino and I. Navarro and A. Martinoli},

url = {https://ieeexplore.ieee.org/document/7995979},

doi = {10.1109/IVS.2017.7995979},

year  = {2017},

date = {2017-06-11},

urldate = {2017-07-31},

booktitle = {IEEE Intelligent Vehicles Symposium (IV)},

address = {Redondo Beach, CA, USA},

abstract = {The convergence of sensor-based vehicle automation and Inter-Vehicle Communication (IVC) will be a key to achieve the full automation of vehicles. In this paper we present a new method for the design and performance evaluation of Cooperative Automated Driving (CAD) systems, based on a bidirectional coupling of vehicle and network simulators (Webots and ns-3). The coupling exploits the comprehensive capabilities of the simulators at a reasonable computational complexity and allows simulating CAD systems with high accuracy. We demonstrate the capabilities of the simulation tool by a case study of convoy driving with automated vehicles using a fully distributed control algorithm and IVC. The study compares CAD-specific metrics (safety distance, headway, speed) for an ideal and a realistic communication channel. The simulation results underline the need of accurate modeling and give valuable insights for the design of CAD systems.},

keywords = {simulation, V2X communication},

pubstate = {published},

tppubtype = {inproceedings}

}

@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}

}