V2X – Communication of a vehicle with its surroundings

General principles

V2X communication – Vehicles-to-everything, i.e. communication of a vehicle with its surroundings – offers the possibility of sharing information between any vehicle and its surroundings be it other vehicles or traffic infrastructure. This communication is based on the European standard ITS – G5 (sometimes C2X – Car to Car). Our company is one of the biggest manufacturers of units with this technology and thanks to the recently realized projects we also belong to the biggest manufacturers in the public transportation field in Europe. We developed both HW and SW of the units ensuring high solution flexibility based on the needs of individual customers.

We offer both basic V2X communication elements that are based on  units UCU 5.0. These are:

• OBU units – On-board unit – vehicle units (various types)
• RSU unis – Road-side unit – unis for traffic infrastructure, sometimes also called stationary units

So far we have supplied 1500 OBU vehicle units and 150 RSU. We have prepared solutions for the following areas of intelligent transportation systems:

• Public transportation – thanks to the close integration with our on-board computer EPIS 4.0x it is possible to transfer traffic data and warnings to the on-board computer ant to use information from the on-board computer to create warning messages sent via V2X. The possibility of vehicle preference at intersections is a great advantage of V2X.
• Individual personal transportation – thanks to tablet connection we can display relevant warning to drivers
• Emergency services – our units (OBU in cooperation with RSU and intersection controller unis) provide ES vehicle preference at intersections. Simultaneously, ES vehicles inform vehicles in the surrounding area about their presence which can contribute their easier passage through a city in the future.
• Roadway and highway management – when integrated with the Back Office system, RSU units can send warning messages, maintenance vehicles can use OBU to inform about their presence and to recommend suitable behavior to other traffic participants.
• Municipal road management – our RSU unis in cooperation with traffic lights controller units can provide ES and public transportation vehicle preference. When cooperating with controller units from the Cross company our RSU broadcast both intersection maps and up to date signal plans.

Our customers are transportation companies (DPMB a.s., DPO a.s.), ES – Fire brigade in Brno, roadway and highway managers – ŘSD (Management of Roadways and Highways)  and Brno Roadways – and municipal authorities.

Properties of our solution

• As already stated our solution is based on our own hardware and software. We also developed our own communication stack that fully meets international standards defined by the ETSI organization – we successfully participated in Plugtest in France. The basic properties of our solution:

• High quality radio technology, providing wide reach of our units – 300 meters in a city and 1500 meters outside of a city,
• Support of all types of messages V2X – CAM, DENM, IVI, MAP, SPAT, SRM, SSM, including reception, processing and generation of these messages,
• Support of forwarding these messages
• Support of securingV2X communication,
• Using maps to create messages and to locate vehicles on a map,
• Effort to achieve maximum decentralization of the system – every vehicle and RSU are independent units that use local information sources to make decisions – on-board computers, intersection controller units, inner sensors.

Thanks to our development we know the weaknesses and the strengths of  V2X and we use this knowledge to adapt our proposal.

OBU units

OBU units – our unit UCU 5.0V – offered in many versions adapted to specific usage types. Our units can be installed in passenger cars, trucks, buses, trolleybuses, trams and warning trailers – our units have all needed approvals and certifications.

UCU units are equipped with a V2X communication module and an LTE module (up to two independent modems), GNSS (GPS, Galileo, Glonass), Wi-Fi access point / client, an inertial measurement unit (Accelerometer, Gyroscope) and a number of communication busbars (2x Ethernet out of which 1x 1 Gbit/s, RS-485, RS-232, CAN) + one-bit inputs / outputs.

Tablets displaying relevant messages and warnings received via V2X are prepared for interaction with drivers. We also prepared integration with on-board computers which enables them to display warnings.

Maps are used by OBU to crate correct warning messages. OBU units are also able to localize these maps and thus information about the speed limit, roadway type, etc is also available.

Scripts and behaviors that are prepared in our OBU units and that are generated by the units autonomously include:

• Warning against slow and stationary vehicles on a highway  – Slow and Stationary vehicle warning
• Warning against abruptly braking vehicles – Emergency braking warning
• Warning against roadworks – Roadworks warning
• Warning against a public transportation vehicle at a stop
• Warning against impending tram collisions
• Warning against coming ES vehicles
• Information about the state of public transportation vehicles
• Public transportation vehicle preference at intersections
• Vehicle preference (priority) at intersections
• Waring against rails and road intersecting

RSU units

RSU units – our units UCU 5.0I – offered as independent RSU or as units cooperating with intersection controller units. The units can be installed in distributors or independently on columns, typically of traffic lights.

The unit are supplied including high-performance antennas providing sufficient reach and good V2X reception. They also include an LTE modem, GNSS (exact time and unit setting based on its position) and a sufficient amount of communication busbars.

Our RSU units are designed for non-stop operation and they are built to withstand tough outdoor conditions.

Prepared scripts for RSU:

• Broadcasting of a signal plan and an intersection map for RSU connected to an intersection controller unit made by the Cross company
• Public transportation preference at intersections – in cooperation with intersection controller units
• ES vehicle preference at intersections – in cooperation with intersection controller units
• Vehicle counting – PVD – Probe Vehicle Data
• Broadcasting of any DENM and IVI warning messages that are to be displayed to drivers – messages can be activated externally by Back office (BOS) servers, or permanently saved in the unit.

RSU can also use maps e.g. for calculating the actual distance of a vehicle from an intersection.