A city-scale 5G automative testbed for open experimentation
Vehicular networks are seen as one of the key enablers for the always-connected paradigm, providing useful communications among vehicles and between vehicles and the infrastructure. As a natural consequence, the design and implementation of Intelligent Transportation Services (ITS) applications has been a hot topic, and a proper evaluation of these applications must consider a realistic environment. This article presents the IT-Av automotive testbed, a city-scale multi-communication vehicular environment with virtualization capabilities, along with some of the services and applications already evaluated through external partners. This platform has been used as the automotive test site of Horizon 2020 project 5GinFIRE.
When considering vehicular networks, simulation tools are probably the most used environment for the evaluation of new proposals. This is valid not only for the network layer (routing protocols, channel access management, etc.), but also when addressing new applications and services. Acknowledging that network simulators are getting more and more accurate when representing a real scenario, they are far from acceptable when in driving assistance and safety situations. In these cases, the evaluation environment should be as close as possible to the real scenario.
An automotive testbed, deployed in the campus of the University of Aveiro, Portugal, and managed by Instituto de Telecomunicações – Aveiro, has been widely used for the evaluation of new services and applications for the vehicular vertical. In its current state, the vehicular testbed consists of On-Board Units (OBUs), deployed in vehicles, and Roadside Units (RSUs). The OBUs (and therefore the vehicles) are able to connect to each other via standard IEEE 802.11p/WAVE links, and are able to connect to the RSUs through IEEE 802.11p/WAVE, IEEE 802.11n/WiFi and/or cellular links, in a multihomed communication.
The simultaneous connectivity between the OBU and the RSUs, through the available interfaces, is also possible, enabling the choice of the services to be transmitted through each technology. RSUs are connected through Ethernet to a central entity, responsible for coordinating the vehicles’ handovers, and provide Internet connectivity through every RSU connection. The cellular network is granted through a small cell C-RAN using Band 7 (2.6GHz) powered by an OpenAirInterface (OAI) Evolved Packet Core (EPC). The figure illustrates the IT-Av automotive architecture in its current status.
Each OBU is equipped with an additional IEEE 802.11n/WiFi interface, to disseminate a WiFi connection to end-users, usually vehicle occupants, to have connectivity to the Internet. In order to grant transparent handovers to the end-user, a mobility solution based on N-PMIPv6 is applied. Moreover, each vehicle has access to its information such as velocity, GPS and heading, and is also equipped with in-Car Node Processors that can be used to increase the computational power of the OBUs.
The IT-Av automotive testbed has been in constant upgrade. As a result of the participation in the 5GinFIRE project, the testbed is now enabling resource sharing, making use of softwarized networks, replacing hardware network functions through software functions by the means of Network Function Virtualization (NFV) technologies. This way, network functions, as well as many other applications, are available in the Cloud, enabling flexibility, programmability and extensibility to the network.
IT-Av automotive testbed architecture
The IT-Av automotive testbed has been thoroughly explored, not only in the scope of research projects, as is the case of 5GinFIRE, but also for in-house research activities. The scope of the experiments exploring the IT-Av automotive testbed has been considerably wide, ranging from automotive safety up to multimedia, highlighting its importance and applicability.
Going into detail in some of the previous experiments, SURROGATES (https://5ginfire.eu/
surrogate/) explored the virtualization of instances of OBUs at the edge of the vehicular network to foster 5G vehicular services, by extending their capabilities and offloading processing tasks from the same unit to its virtualized representative in
the cloud. Focused on the safety topic, the VRU-Safe experiment (https://5ginfire.eu/vru-safe/) explored prediction mechanisms to avoid vehicular accidents using a hybrid architecture combining Edge and Cloud Computing to identify and predict potential imminent road hazards involving Vulnerable Road Users and vehicles.
Focusing on multimedia, the CAVICO experiment (https://5ginfire.eu/cavico/) explores the use of Cloud virtualization to push the boundaries of the QoE-aware adaptive streaming by virtualizing context-aware mechanisms that can use no-reference, context-based QoE metric subsets, to allow a single system to cope with many use case scenarios, e.g. to remotely operate automotive cars. To that end, a video transcoder module, virtualized in the Cloud, is dedicated to optimising video streaming in the function of quality parameters read from network radio interfaces and video streams in the vehicular network. Regarding public safety, the 5G-CAGE experiment (https://5ginfire.eu/5g-cage/) explored a virtualized city safety solution to monitor and analyse video streams collected from heterogeneous and distributed sources. The analysis is performed in the Cloud, using machine learning techniques on top of video streams gathered from diverse video sources, supplying advanced features for detection of city safety elements, such as license car plates.
A new version
In an update operation, the Instituto de Telecomunicações along with its technological partners, namely Altice Labs, University of Aveiro and the Municipality of Aveiro, are extending and upgrading the automotive testbed. Funded by an EU project under the Urban Innovative Actions programme, the Aveiro STEAM City (https://uia-initiative.eu/en/uia-cities/aveiro) is building a city-scale 5G network in the city of Aveiro. This infrastructure, that will support the expansion of the current automotive testbed, will count with 25 reconfigurable radio units, ready to operate under the 5G standards, connected through optical fibre up to the 5G core, located in IT premises.
To complement the 5G cellular network, the infrastructure will also include a renovated version of the vehicular network mentioned before. In detail, each OBU will be equipped with Cellular-Vehicle to Everything (C-V2X) technology. With this technology, OBUs will be able to communicate with each other through the PC5 interface, being capable of achieving higher throughputs when compared to IEEE 802.11p/WAVE technology. This new testbed will also enable the software virtualization in the edge of the vehicular network (i.e. in the OBUs), extending the actual virtualization features solely in the Cloud.
The IT-Av automotive testbed offers a complete playground for the development and assessment of new ITS applications and network mechanisms. Due to its integrated multi-communication solution and edge virtualization capabilities, the range of services to be explored are countless: road safety (e.g., collision detection, lane change warning, and cooperative merging), smart and green transportation (e.g., traffic signal control, intelligent traffic scheduling, and fleet management), location-dependent services (e.g., point of interest and route optimization), in-vehicle Internet access, and many more.
Further information is available on the 5GinFIRE website at http://5ginfire.