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See detailA Study on Highway Traffic Flow Optimization using Partial Velocity Synchronization
Forster, Markus UL; Frank, Raphaël UL; Engel, Thomas UL

in Proceedings of the 1st GI/ITG KuVS Fachgespräch Inter-Vehicle Communication (FG-IVC 2013) Technical Report CCS-2013-01 (2013)

In this paper we present a study of highway traffic flow optimization using Partial Velocity Synchronization (PVS). PVS is a Cellular Automaton (CA) model that is extended by a communication layer ... [more ▼]

In this paper we present a study of highway traffic flow optimization using Partial Velocity Synchronization (PVS). PVS is a Cellular Automaton (CA) model that is extended by a communication layer providing the ability to exchange relevant information between vehicles. We show that it is possible to enhance traffic flow on highways significantly with a small number of velocity recommendations computed from the traffic conditions ahead. Furthermore we show that only a limited number of hops in an information chain is necessary to reschedule the vehicles on a given highway segment to avoid the formation of shockwaves. Our results show that traffic flow will be increased while travel time and emissions will be reduced dramatically. [less ▲]

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See detailLuxTraffic: A Collaborative Traffic Sensing System
Kovacheva, Aleksandrina; Frank, Raphaël UL; Engel, Thomas UL

in Proceedings of the 19th IEEE Workshop on Local & Metropolitan Area Networks (LANMAN'13) (2013)

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See detailEnergy-Efficient Rate-Adaptive Passive Traffic Sensing using Smartphones
Frank, Raphaël UL; Melakessou, Foued UL; Castignani, German UL

in Proceedings of the 12th Annual Mediterranean Ad Hoc Networking Workshop (MedHocNet 2013) (2013)

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See detailTowards Collaborative Traffic Sensing using Mobile Phones
Frank, Raphaël UL; Mouton, Maximilien UL; Engel, Thomas UL

in Proceedings of the IEEE Vehicular Networking Conference 2012 (2012)

Participatory mobile sensing applications are becoming increasingly popular. The growing population of privately-held mobile smartphones enables a plethora of new services. One of the most promising ... [more ▼]

Participatory mobile sensing applications are becoming increasingly popular. The growing population of privately-held mobile smartphones enables a plethora of new services. One of the most promising application areas is collaborative traffic sensing. Here, smartphones are used as mobile sensors to collect and share relevant location information in order to reconstruct a global picture of the traffic situation in a monitored area. There are several challenges that need to be addressed in order to provide an efficient and ubiquitous service. In this talk we present how low-cost mobile smartphones can be used for such services without compromising the everyday usage of the device. We first test several sensing policies and evaluate how they affect location accuracy and battery life. We then perform a penetration rate study to identify the proportion of participants required to provide good service by varying several parameters. The outcome shows that if configured correctly, smartphones can be used as accurate mobile traffic sensors providing important information even at low penetration rates. [less ▲]

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See detailImproving Highway Traffic through Partial Velocity Synchronization
Forster, Markus UL; Frank, Raphaël UL; Gerla, Mario et al

in Proceedings of the IEEE Global Communications Conference 2012 (2012)

In this paper we address the problem of uncoor- dinated highway traffic. We first identify the main causes of the capacity drop, namely high traffic demand and inadequate driver reaction. In the past ... [more ▼]

In this paper we address the problem of uncoor- dinated highway traffic. We first identify the main causes of the capacity drop, namely high traffic demand and inadequate driver reaction. In the past, traffic and user behavior have been accurately described by cellular automata (CA) models. In this paper we extend the CA model to deal with highway traffic fluctuations and jams. Specifically, the model incorporates the communication layer between vehicles. The model thus enables us to study the impact of inter-vehicular communications and in particular the delivery of critical and timely upstream traffic information on driver reaction. Based on the newly-available traffic metrics, we propose an Advanced Driver Assistance System (ADAS) that suggests non-intuitive speed reduction in order to avoid the formation of so-called phantom jams. The results show that using such a system considerably increases the overall traffic flow, reduces travel time and avoids unnecessary slow-downs. [less ▲]

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See detailA Survey on the Performance of Commercial Mobile Access Networks
Frank, Raphaël UL; Forster, Markus UL; Mario, Gerla et al

Report (2012)

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See detailCORNER: A Radio Propagation Model for VANETs in Urban Scenarios
Giordano, Eugenio; Frank, Raphaël UL; Pau, Giovanni et al

in Proceedings of the IEEE (2011), 99(7), 1280-1294

Advances in portable technologies and emergence of new applications stimulate interest in urban vehicular communications for commercial, military, and homeland defense applications. Simulation is an ... [more ▼]

Advances in portable technologies and emergence of new applications stimulate interest in urban vehicular communications for commercial, military, and homeland defense applications. Simulation is an essential tool to study the behavior and evaluate the performance of protocols and applications in large-scale urban vehicular ad hoc networks (VANET). In this paper, we propose CORNER, a low computational cost yet accurate urban propagation model for mobile networks. CORNER estimates the presence of buildings and obstacles along the signal path using information extrapolated from urban digital maps. A reverse geocoding algorithm is used to classify the propagation situation of any two nodes that need to communicate starting from their geographical coordinates. We classify the relative position of the sender and the receiver as in line of sight (LOS) or nonline of sight (NLOS). Based on this classification, we apply different formulas to compute the path loss (PL) metric. CORNER has been validated through extensive on-the-road experiments, the results show high accuracy in predicting the network connectivity. In addition, on-the-road experiments suggest the need to refine the fading model to differentiate between LOS, and NLOS situations. Finally, we show the impact of CORNER on simulation results for widely used applications. [less ▲]

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See detailPerformance Bound for Routing in Urban Scenarios
Frank, Raphaël UL; Giordano, Eugenio; Gerla, Mario et al

in Proceedings of the 7th Asian Internet Engineering Conference (AINTEC 2011) (2011)

In this paper we present a novel evaluation methodology for the comparison of ad hoc routing protocols in urban scenarios applied to inter-vehicular communications. We introduce a new route evaluation ... [more ▼]

In this paper we present a novel evaluation methodology for the comparison of ad hoc routing protocols in urban scenarios applied to inter-vehicular communications. We introduce a new route evaluation metric that identifies the goodness of a given route. Through analysis of subsequent mobility snapshots of the network topology, we compute an optimal route between two communicating vehicles. We compare the properties of the obtained route to the most representative routing approaches namely reactive and proactive routing. Based on this evaluation we provide a detailed discussion on the pros and cons of the different schemes when applied to urban scenarios. [less ▲]

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See detailEfficient Data Dissemination Techniques For Multi-Hop Wireless Networks Applied to Vehicular Communications
Frank, Raphaël UL

Doctoral thesis (2010)

Multi-Hop Wireless Networks (MHWN) are composed of devices called nodes, which communicate in an ad hoc fashion. Such networks allow the relaying of transmissions over multiple wireless hops to provide an ... [more ▼]

Multi-Hop Wireless Networks (MHWN) are composed of devices called nodes, which communicate in an ad hoc fashion. Such networks allow the relaying of transmissions over multiple wireless hops to provide an extended service area. There are two main classes of MHWN. The first includes all networks that have a static network topology, e.g. Wireless Mesh Networks and Wireless Sensor Networks. The second specifies networks with a dynamic or mobile topology, e.g. Vehicular Networks. For both types, collaborative applications are of great importance. In such a scenario, information needs to be made available to multiple, or sometimes all nodes in the network. The trivial method, pure network flooding, is to retransmit the information at every hop exactly once. In previous studies it has been shown that such an approach considerably lowers the overall performance of the network by saturating the shared communication channel. In this thesis, we present two different approaches that perform efficient data dissemination among collaborative nodes in MHWNs. The primarily objective is to reduce the number of redundant retransmissions by selecting only a subset of nodes to be responsible for relaying the information without compromising global delivery. We propose one approach for each of the two classes using different methodologies. For static network topologies, we present a novel heuristic based on the Minimum Connected Dominating Set problem. This approach allows the election of a near-optimal set of relays that are able to reach every other node in the network, thus minimizing the number of retransmissions. We theoretically and experimentally validate our approach and compare it to other state-of-the-art dissemination techniques. For dynamic network topologies, we focus primarily on Vehicular Networks. We present a new routing protocol that makes use of an efficient dissemination technique to find robust communication paths between two vehicles. Strategic vehicles are elected as relays based on their position and on information about the local neighborhood. The protocol is evaluated using a novel simulation framework that takes into account specific characteristics of vehicular networks in urban environments, e.g. mobility of the vehicles and signal propagation. The performance evaluation shows that our protocol introduces only a low control overhead and provides robust communication paths that achieve high delivery ratios. [less ▲]

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See detailEDFS A Novel Flooding Protocol for Multi-Hop Wireless Networks
Frank, Raphaël UL; Scherer, Thomas UL; Gerla, Mario

in Proceedings of the Seventh International Conference on Wireless On-demand Network Systems and Services (WONS'10) (2010)

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See detailTrafRoute: A Different Approach to Routing in Vehicular Networks
Frank, Raphaël UL; Giordano, Eugenio; Cataldi, Pasquale et al

in Proceedings of the IEEE 6th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob) (2010)

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See detailCORNER: a Realistic Urban Propagation Model for VANET.
Giordano, Eugenio; Frank, Raphaël UL; Pau, Giovanni et al

in Proceedings of the Seventh International Conference on Wireless On-demand Network Systems and Services (WONS'10) (2010)

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See detailCORNER: A Step Towards Realistic Simulations for VANET
Giordano, Eugenio; Frank, Raphaël UL; Pau, Giovanni et al

in Proceedings of the seventh ACM international workshop on VehiculAr InterNETworking (2010)

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See detailInteroperable Networking Applications for Emergency Services
Frank, Raphaël UL; Hourte, Benjamin; Jungels, Dan et al

in International Journal of Multimedia and Ubiquitous Engineering (2009), 4(1), 1122

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See detailTwo Ray or not Two Ray this is the price to pay
Giordano, Eugenio; Frank, Raphaël UL; Ghosh, Abhishek et al

in Proceedings of the IEEE 6th International Conference on Mobile Adhoc and Sensor Systems (MASS '09) (2009)

Detailed reference viewed: 69 (0 UL)
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See detailEmergency Group Calls over Interoperable Networks
Frank, Raphaël UL; Scherer, Thomas UL; Engel, Thomas UL

in Proceedings of the 11th IEEE International Conference on Computational Science and Engineering (2008)

Detailed reference viewed: 66 (0 UL)
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See detailTree Based Flooding Protocol for Multi-Hop Wireless Networks
Frank, Raphaël UL; Scherer, Thomas UL; Engel, Thomas UL

in Proceedings of the 3rd International Conference on Broadband Communications, Information Technology & Biomedical Applications (2008)

Detailed reference viewed: 86 (1 UL)
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See detailA Governmental Vision on Public Safety Group Calls and Object Tracing
Frank, Raphaël UL; Scherer, Thomas UL; Simon, Carlo et al

in Proceedings of the 14th Annual Conference on Disaster Recovery And Relief, Current & Future Approaches (2007)

Detailed reference viewed: 55 (5 UL)