A Cooperative Advanced Driver Assistance System to Mitigate Vehicular Traffic Shock Waves

in IEEE INFOCOM 2014 - IEEE Conference on Computer Communications (2014)

We address the problem of shock wave formation in uncoordinated highway traffic. First, we identify the combination of heavy traffic and small traffic perturbations or unexpected driver actions as the ... [more ▼]

We address the problem of shock wave formation in uncoordinated highway traffic. First, we identify the combination of heavy traffic and small traffic perturbations or unexpected driver actions as the main causes of highway traffic jams. Then we introduce a novel distributed communication protocol that enables us to eliminate upstream shock wave formation even with low system penetration rates. Based on traffic information ahead, we propose a Cooperative Advanced Driver Assistance System (CADAS) that recommends non-intuitive velocity reductions in order to redistribute traffic more uniformly thereby eliminating traffic peaks. Simulation results show that CADAS significantly increases the average velocity and therewith reduces the overall travel time and avoids unnecessary slowdowns. [less ▲]

Improving Highway Traffic through Partial Velocity Synchronization

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 ▲]

Performance Bound for Routing in Urban Scenarios

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 ▲]

EDFS A Novel Flooding Protocol for Multi-Hop Wireless Networks

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

CORNER: A Step Towards Realistic Simulations for VANET

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

Performance Improvement in Wireless Networks using Cross-layer ARQ

in Computer Networks (2007), 51(15), 4396-4411

This paper presents a novel cross-layer approach (LLE-TCP) designed for performance enhancement of TCP over a large variety of wireless networks. LLE-TCP avoids TCP ACK packet transmission over the ... [more ▼]

This paper presents a novel cross-layer approach (LLE-TCP) designed for performance enhancement of TCP over a large variety of wireless networks. LLE-TCP avoids TCP ACK packet transmission over the wireless channel. As a result, the saved time can be utilized by the nodes for data packet delivery. The proposed scheme enhances the protocol stacks of the wireless sender (or a base station) and the receiver with cross-layer ARQ agents which support ACK suppression. ARQ agent suppresses the outgoing ACKs at the receiver side and generates them locally at the sender or base station. The performance evaluation of the proposed approach is performed via simulations as well as IEEE 802.11 testbed experiments for single-hop and infrastructure network scenarios. LLE-TCP demonstrates the performance improvement in the range of 20–100% depending on the transmitted TCP/IP datagram size. Among the factors contributing to performance enhancement are: medium busy time reduction, reduced sensibility to link errors, reduced round trip time (RTT), and improved congestion control. A good level of throughput fairness as well as a fair coexistence with state-of-the-art TCP modifications ensures proper functionality of the proposed approach, while performance advantages extended even on non-LLE-TCP users favor an incremental deployment of the technique in existing networks. [less ▲]