Lara Codeca

Luxembourg SUMO Traffic (LuST) Scenario: 24 hours of mobility for vehicular networking research

Different research communities varying from telecommunication to traffic engineering are working on problems related to vehicular traffic congestion, intelligent transportation systems, and mobility patterns using information collected from a variety of sensors. To test the solutions, the first step is to use a vehicular traffic simulator with an appropriate scenario in order to reproduce realistic mobility patterns. Many mobility simulators are available, and the choice is usually done based on the size and type of simulation required, but a common problem is to find a realistic traffic scenario. In order to evaluate and compare new communication protocols for vehicular networks, it is necessary to use a wireless network simulator in combination with a vehicular traffic simulator. This additional step introduces further requirements for the scenario. The aim of this work is to provide a scenario able to meet all the common requirements in terms of size, realism and duration, in order to have a common basis for the evaluations. In the interest of building a realistic scenario, we decided to start from a real city with a standard topology common in mid-size European cities, and real information concerning traffic demands and mobility patterns. In this paper we show the process used to build the Luxembourg SUMO Traffic (LuST) Scenario, and present a summary of its characteristics together with an overview of its possible use cases.

MoViT: the mobile network virtualized testbed

MoViT is a distributed software suite for the emulation of mobile wireless networks. MoViT provides researchers and developers with a virtualized environment for developing and testing mobile applications and protocols for any hardware and software platform that can be virtualized. The distributed nature of MoViT allows for the emulation of mobile networks of arbitrary size. Additionally, the network connectivity is shaped transparently such that the connectivity observed by each virtual node resembles that of a physical mobile network. In this paper we present the MoViT architecture, the models used to emulate the wireless channel, the details of our initial implementation and, finally, the results of our evaluation regarding the scalability, realism, and versatility of MoViT.

Luxembourg SUMO Traffic (LuST) Scenario: Traffic Demand Evaluation

Both the industrial and the scientific communities are working on problems related to vehicular traffic congestion, intelligent transportation systems, and mobility patterns using information collected from a variety of sources. Usually, a vehicular traffic simulator, with an appropriate scenario for the problem at hand, is used to reproduce realistic mobility patterns. Many mobility simulators are available, and the choice is made based on the type of simulation required, but a common problem is finding a realistic traffic scenario. The aim of this work is to provide and evaluate a scenario able to meet all the basic requirements in terms of size, realism, and duration, in order to have a common basis for evaluations. In the interest of building a realistic scenario, we used information from a real city with a typical topology common in mid-size European cities, and realistic traffic demand and mobility patterns. In this paper, we show the process used to build the Luxembourg SUMO Traffic (LuST) Scenario, and present a summary of its characteristics together with our evaluation and validation of the traffic demand and mobility patterns.

Traffic Routing in Urban Environments: The Impact of Partial Information

There are many studies concerning the problem of traffic congestion in cities. One of the best accepted solutions to relieving congestion involves optimization of resources already available, by means of balancing traffic flows to minimize travel delays. To achieve this optimization, it is necessary to collect and process Floating Car Data (FCD) from vehicles. In this paper we evaluate the repercussions of partial information on the overall traffic view, and consequently on the outcome of the optimization. Our study focuses on the role of the user participation rate and the availability of Road Side Units to collect the FCD. By means of simulation we quantify the impact of partially-available information on the computation of route optimization, and how it impedes traffic flows. Our results show that even minor uncertainties can significantly impact routing strategies and lead to deterioration in the overall traffic situation.

On the evaluation of make-before-break handovers in urban WiFi networks for moving vehicles

Due to the increasing deployment of city-wide IEEE 802.11 networks for nomadic Internet access, there is a great potential for users wanting to access the network while being on the move. However, due to the limited coverage range of single access points in these networks, handovers between them need to be carefully managed. This issue becomes critical if we consider vehicular users, where the high speed and mobility pattern greatly affect the connectivity performance. In this paper, we evaluate the performance of different handover approaches in a real commercial deployment under vehicular mobility constraints. In particular, we consider using a second wireless interface in order to achieve make-before-break handovers. Additionally, we identify some open issues that constrain IEEE 802.11 commercial deployments in providing completely seamless connectivity for moving vehicles.