Vehicles In Network Simulation Research Articles

A Blockchain Assisted Vehicular Pseudonym Issuance and Management System for Conditional Privacy Enhancement

A feasible approach commonly discussed in the literature for mitigating location privacy threats in vehicular ad hoc networks (VANETs) is the use of pseudonyms instead of real vehicle identifications. However, for relevant authorities to be able to identify misbehaving vehicles through their pseudonyms, it is essential that the privacy protection mechanisms only allow for conditional anonymity and not complete anonymity. In this paper, we propose the use of a permissioned consortium blockchain system with smart contract feature to facilitate secure and conditional privacy-preserving vehicular pseudonym issuance and management in a multi-jurisdictional road network. The use of a permissioned consortium blockchain helps mitigate security risks associated with the complexities in interorganizational data handling, such as in the areas of access control, data integrity, confidentiality, and availability. The proposed system architecture takes advantage of the predicted wide availability of Roadside Units (RSUs), and the highly viable, flexible and mature Public Key Infrastructure (PKI) technology for usage in vehicular pseudonymous communications. We successfully carried out a small-scale simulation of the proposed architecture using the Vehicles in Network Simulation (Veins) platform for integrated traffic and network simulation services (SUMO as the traffic simulator and OMNeT++ as the network simulator), and the Hyperledger Fabric platform as the permissioned consortium blockchain system. Simulation and performance analysis results reveal the feasibility of practical deployment of the scheme, and show that the scheme addresses the identified shortfalls of existing works, including the ability to achieve a better balance between connectivity and storage requirements.

Cooperative Overtaking Assistance System Based on V2V Communications and RTDB

Abstract Overtaking maneuvers in roads cause a large number of accidents. To prevent collisions, numerous cooperative overtaking assistance systems, based on Vehicular Ad hoc Networks (VANET), have been proposed. However, these systems may meet problems in case of data congestion or data loss. To improve overtaking safety, this paper studies the use of Vehicle-To-Vehicle (V2V) communications and Real-Time DataBases (RTDB). More precisely, we suggest a new integrated system, called Cooperative Overtaking Assistance Persistent System (COAPS), to better avoid potential collisions during overtaking maneuvers. Each vehicle stores its information in a local RTDB, along with the adjacent vehicles’ information. While detecting an overtaking intention, the vehicle COAPS queries its database and selects the preceding vehicle(s) and the oncoming one(s) from the other direction to make decision about the overtaking. It controls the overtaking in case of positive decision or reduces the vehicle speed to avoid a collision ahead, in the other case. Simulations of different driving scenarios, under the Vehicles In Network Simulation (VEINS) framework, show that COAPS provides a high level of overtaking safety due to the V2V communications, the RTDB and the notion of Quality of Data used to reduce the number of data freshness transactions.

V2V‐based method for the detection of road traffic congestion

The traffic congestion detection based on the internet of vehicles is gaining enormous research interest. A vehicle-to-vehicle (V2V)-based method for the detection of road traffic congestion is proposed. Firstly, a fuzzy controller was constructed based on the vehicle speed, traffic density, and traffic congestion rating system, and the level of local traffic congestion was evaluated. Then, the level of local traffic congestion of neighbouring vehicles was queried based on V2V communication, and the level of regional traffic congestion was obtained based on a large sub-sample hypothesis test. Finally, a simulation test platform was built based on vehicles in network simulation, and the back-off time slots and received packets of vehicle nodes were calculated. The accuracy of the proposed method for detecting road traffic congestion was compared to the cooperative traffic congestion detection (CoTEC) method and the geomagnetic coil method. The results show that the detection accuracy of the proposed method increased by 5.5 and 7.5%, respectively, compared to the geomagnetic coil method and CoTEC method. The V2V communication network overhead of the proposed traffic congestion detection method is reduced by 90.8% compared to the adopted CoTEC method. The communication overhead of the vehicle node using the proposed method is significantly decreased when there is no traffic congestion.

Sophisticated Spectrum Sharing Analysis: The Case of the 5.9 GHz Band

Efficient spectrum sharing is becoming more critical as the demand for wireless services increases across many industries and available bandwidth remains scarce. To respond to this need, regulators must understand inter-system interactions in specific spectrum sharing scenarios in order to make informed policy judgments. These decisions are best made through risk-informed interference analysis, rather than worst-case advocacy, as noted by De Vries (2017) and many other scholars. Nowhere is this analytic need more apparent and urgent than the 5.9 GHz frequency band. 5.9 GHz is adjacent to existing Wi-Fi spectrum and a prime candidate to enable highly-demanded wireless broadband services, but it is today allocated exclusively to Dedicated Short Range Communications (DSRC), a technology in development for vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) safety and commercial communications. A sophisticated and realistic technical understanding of coexistence between Wi-Fi and DSRC is therefore central to this archetypal spectrum sharing case study – an understanding that, to date, has been lacking, leading to a nearly five-year policy stasis since the FCC initially proposed sharing for this band in 2013. This paper uses radio frequency (RF) engineering and computer science techniques to provide the necessary technical foundation for spectrum sharing policy in 5.9 GHz. Specifically, we use lab-based RF measurements as the foundation for simulation of real-world system interaction between Wi-Fi and DSRC, with a particular focus on how the presence of adjacent channel Wi-Fi impacts the performance of the crash-avoidance safety application of DSRC according to the leading strategy for sharing 5.9 GHz, known as the re-channelization plan, which is described further in this paper. Lab-based RF measurements provide actual DSRC performance impacts at different inter-system configurations, which are then anchored to a network and road traffic simulation that captures the behavior of Wi-Fi and DSRC in an actual cityscape with observed vehicular volume and movement patterns. DSRC system architects define its key performance indicator as packet error rate (PER). In this paper we build on PER and define a risk-informed metric called safety alert failure rate (SAFR) which focuses on the failure rate for packets that have an impact on safety outcomes in real world traffic scenarios, consistent with risk-informed spectrum policy analysis. We use an open-source vehicular traffic simulator known as Veins (Vehicles in Network Simulation) to observe the DSRC SAFR for over 20,000 vehicles traveling during rush hour in Bologna, Italy, with the presence of Wi-Fi interference. This approach is data-intensive and enables calculation of SAFR in scenarios where vehicular traffic makes collisions probable – which is the inter-system interaction of greatest concern for spectrum policymakers. In so doing, we provide a path forward for policy in this important frequency band. We observe that DSRC SAFR is not impacted by the presence of Wi-Fi traffic in the adjacent channel. We also observe that the SAFR is above the levels deemed by DSRC architects to be harmful to system performance in the majority of locations simulated; however, since this result is not due to Wi-Fi interference, we conclude that it is most likely attributed to DSRC system instability in high vehicular traffic scenarios. We perform a number of checks to demonstrate the robustness of these conclusions. Our results therefore suggest that regulators can successfully enable Wi-Fi use of the 5.9 GHz band without impacting DSRC safety efficacy. This finding provides the necessary technical foundation for policy in an important frequency band, and provides a valuable case study for rigorous analysis in spectrum sharing scenarios more generally.

Vehicular ad-hoc network simulations of overtaking maneuvers on two-lane rural highways

The objective of this paper is to evaluate the effectiveness of a dedicated short-range communication (DSRC)-based wireless vehicle-to-vehicle (V2V) communication system, called the overtaking assistant, devised for improving safety during overtaking (also referred to as passing) maneuvers on two-lane rural highways. Specifically, the paper examines the influence of vehicular kinematics (vehicle speeds, accelerations and distances), driver behavior (drivers’ perception/reaction time and overtaking rate), and DSRC characteristics (power settings, communication range, packet errors, sensor errors, and estimation inaccuracy) on the effectiveness of DSRC systems in predicting unsafe overtaking maneuvers. To this end, the paper utilizes a microscopic traffic simulator called VEhicles In Network Simulation (VEINS) that supports the simulation of wireless communication protocols in Vehicular Ad-hoc NEtworks (VANETs). 18,000 overtaking maneuvers – with roughly 10,000 collision maneuvers – were simulated to consider heterogeneity in vehicular kinematics, driver behavior, and DSRC performance. The overtaking assistant predicts whether a collision will occur and warns the driver before the maneuver begins. A descriptive analysis followed by a multivariate analysis (using binary discrete outcome models) of the simulated data reveals that the majority of collisions that could not be detected were due to the vehicles being out of communication range for the communication power settings used in the simulation. Packet errors, or failed communications, at a rate of up to 50% did not have a significant influence on the ability to detect collisions. These results suggest that the most important step in paving the way toward advanced driver assistance systems for rural highway overtaking maneuvers is to broaden the communication range of DSRC devices.

Heterogeneous Configuration: A Better Approach to Analyze VANET

A Vehicular Ad-hoc Network (VANET) is an area of wireless technologies that has the property of high node mobility and dynamic topology. In this paper we focus on technology which has major role in avoiding accidents using homogeneous and heterogeneous configurations in different VANET scenarios. For this purpose OMNET++ and VEINS (Vehicles in Network Simulation) is used as the developing platform. Simulation shows that heterogeneous configuration achieve better performance than homogeneous configuration when compared in four different node densities i.e. 20, 30, 40 and 50 nodes in terms of back off time, sent packet, lost packet and busy time.

Improving VANET Performance with Heuristic and Adaptive Fuzzy Logic Scheme

Rapid topology change in vehicular ad hoc network (VANET) is common due to the inherent high mobility nodes and unpredictable environments in VANET. In order to ensure efficient packet transmission, nodes in VANET should react adaptively to topology change in VANET. In this paper, we present a new heuristic and adaptive fuzzy logic scheme (HaFL), which adapts the contention window size and transmission power according to network and traffic conditions. The current existing schemes in VANET utilize only a single parameter to optimize the contention window and transmission power without consideration on the effects of interference as one of the main factors in VANET transmission degradation. In VANET, packet loss can occur at different stages of transmission due to interference or due to elapsed time. In the proposed HaFL, fuzzy logic is used to adaptively optimize the contention window size based on three parameters namely collision rate, SINR and queue overflow which represent packet drop at different stages of transmission. Transmission power which is usually a static parameter is also optimized with consideration on the effects of VANET interference in the proposed HaFL. The performance of the proposed HaFL is evaluated in Vehicles in Network Simulation with road traffic simulator, Simulation of Urban mobility. Simulation results show that the proposed HaFL demonstrates adaptability with improved throughput, low end-to-end delay and higher packet success rate in comparison with the default IEEE802.11p and existing schemes.

Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis

Recently, many efforts have been made to develop more efficient Inter-Vehicle Communication (IVC) protocols for on-demand route planning according to observed traffic congestion or incidents, as well as for safety applications. Because practical experiments are often not feasible, simulation of network protocol behavior in Vehicular Ad Hoc Network (VANET) scenarios is strongly demanded for evaluating the applicability of developed network protocols. In this work, we discuss the need for bidirectional coupling of network simulation and road traffic microsimulation for evaluating IVC protocols. As the selection of a mobility model influences the outcome of simulations to a great extent, the use of a representative model is necessary for producing meaningful evaluation results. Based on these observations, we developed the hybrid simulation framework Veins (Vehicles in Network Simulation), composed of the network simulator OMNeT++ and the road traffic simulator SUMO. In a proof-of-concept study, we demonstrate its advantages and the need for bidirectionally coupled simulation based on the evaluation of two protocols for incident warning over VANETs. With our developed methodology, we can advance the state-of-the-art in performance evaluation of IVC and provide means to evaluate developed protocols more accurately.

Improving the Accuracy of IVC Simulation Using Crowd-sourced Geodata

We discuss the use of crowd-sourced geodata in simulative evaluations of Inter-Vehicle Communication (IVC) protocol designs. Typically, network simulation tools, which have been improved over decades of network research, are used for evaluating communication systems. In the area of IVC, however, additional challenges have to be met. Most important, the mobility of vehicles in network simulation needs to be represented accurately, e.g., using road traffic microsimulation techniques. These can be integrated with network simulation tools in order to provide a holistic view on the overall system performance. Obviously, the quality of these approaches inherently depends on the quality of provided map data. The OpenStreetMap project provides a community-maintained repository under an open license model. The available crowd-sourced geodata not only consists of road topology data but also includes fine-grained details such as traffic lights, speed limits, and even information about buildings, which represent obstacles for wireless communication. Using our Veins simulation framework, we show that this data increases the accuracy of IVC simulation.