Adaptive Transmission Power with Vehicle Density for Congestion Control

The Intelligent Transport Systems (ITS) employs the Vehicular Ad-hoc Networks (VANET) technology to prevent and reduce accidents on highways. VANET uses wireless communication technology that includes protocols and applications that provides safety and non-safety features for a safe and comfortable driving experience. A major problem with VANET is that the network channel utilized for the transmission of network packets for awareness becomes congested due to vehicles competing to use the channel leading to packet loss, high transmission delay and unfair resource usage. These problems would eventually lead to the periodic exchange of Basic Safety Messages not being delivered on time, thereby making VANET unreliable. Researchers have focused on numerous approaches for controlling congestion on the network channel such as adapting the rate of transmission of packets i.e. the number of packets that can be sent per second or adjusting the transmission power which is the distance a packet can travel. An approach is proposed in this thesis to adapt the transmission power, based on the vehicle density state of the network, with the aim of reducing congestion on the network channel and improving the performance of VANET. Results indicate that this can lead to improved performance in terms of reduced packet loss and inter-packet delay

Decentralized Congestion Control Algorithm for Vehicle to Vehicle Networks Using Oscillating Transmission Power

Wireless access in vehicular environments (WAVE) is a vehicle to vehicle (V2V) communications technology which could help prevent up to 82% of non-impaired accidents, according to the US DOT. A 2013 study by the World Health Organization estimated 2,227 road fatalities in 2009 alone. Currently the channel that is responsible for a vehicle’s awareness of others suffers from congestion at moderate loads. In this paper we propose a novel method for adjusting the transmission power in a pattern which alternates between high and low powered transmissions. We modify one commonly used decentralized congestion control (DCC) algorithm, LIMERIC, and compare the power adaptation model against two controls. WAVE supports a 300 meter transmission radius, however, less than 200 vehicles can communicate at the target rate of 10 transmissions per second. We demonstrate that our algorithm reduces the number of packets received by distant vehicles, while maintaining a higher packet rate to the closer vehicles, for which a higher rate is more important

Advances in Vehicular Ad-hoc Networks (VANETs): challenges and road-map for future development

Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks (VANETs) over the past few years. A vehicular network consists of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system (ITS). Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS

5G-Enabled Autonomous Platooning on Robotic Vehicle Testbed

Humanity is progressively moving towards a more intuitive and technological future. The area of Intelligent and Cooperative Transport Systems has revealed itself as one of the areas in great evolution, through technologies of autonomous driving and intravehicle communication. With the main goal of providing accident-free environments as well as optimizing the movement of vehicles on roads all over the world, Vehicle to Everything (V2X) communication is very important when it comes to all kinds of vehicular applications. The CMU|PT FLOYD project focuses on this area, with the aim of developing new systems for possible future implementation. In this report, a vehicular application using a 5G-capable module to perform Vehicle to Infrastructure (V2I) communications was evaluated. This vehicular application is based on an emergency braking scenario, whereby detecting an approaching vehicle in a place where an accident occurred, a message is sent over the network that is picked up by the main vehicle, triggering braking. It should be noted that this sending will be made through the module with 5G capacity, thus being an innovative application. Complementary to this scenario is the tracking of a vehicle by another vehicle, thus making a more complex emergency braking application with a cooperative platoon. This platoon will be maintained through sensors present in the following vehicle, such as LiDAR and ZED camera. With this, image processing and a sensor fusion was done in order to keep the follower at a safe distance but with the ability to follow the leader. In order to validate and test this entire solution, robotic testbeds were used as a low-cost solution, allowing a concrete evaluation, with enlightening physical results of the entire application performed.A humanidade, está a caminhar, progressivamente, para um futuro mais intuitivo e tecnológico. A área dos Sistemas Inteligentes e Cooperativos de Transporte tem-se revelado como uma das áreas em grande evolução, através de tecnologias de condução autónoma e comunicação intra-veicular. Com o objetivo principal de proporcionar ambientes sem acidentes, assim como otimizar o movimento de veículos nas estradas de todo o mundo, a comunicação V2X é muito importante no que toca a todo o tipo de aplicações veiculares. O projeto CMU|PT FLOYD centra-se nesta mesma área, com o intuito de desenvolver novos sistemas de possível implementação futura. Neste relatório, é avaliada assim uma aplicação veicular utilizando um módulo com capacidade 5G para realizar comunicações V2I. Essa aplicação veicular baseiase num cenário de travagem de emergência, em que ao detetar uma aproximação de um veículo num local onde ocorreu um acidente, é enviada uma mensagem pela rede que é captada pelo veículo principal, despoletando a travagem. De destacar que este envio será feito através do módulo com capacidade 5G, sendo desta forma uma aplicação inovadora. Complementado a este cenário está a realização do seguimento de um veículo por parte de um outro veículo, tornando assim uma aplicação mais complexa de travagem de emergência com um pelotão cooperativo. Este pelotão será mantido através de sensores presentes no veículo seguidor como o LiDAR e a ZED camera. Com isto, foi utilizado processamento de imagem e foi feita a fusão de sensores de forma a manter o seguidor a uma distância de segurança mas com capacidade de seguir o líder. Com o objetivo de validar e testar toda esta solução, foram utilizadas plataformas robóticas como solução de baixo custo, permitindo assim ter uma avaliação concreta, com resultados físicos esclarecedores de toda a aplicação realizada