Vehicle-to-everything, or V2X solutions connect road users with each other and the infrastructure. International standards ensure that cars, motorcycles, bicycles and roadside equipment from different manufacturers send messages to each other in a language they all understand.
V2X has a range of more than half a mile and does not require a direct line of sight, expanding the space where we perceive other objects in traffic.
Connectivity in the automotive industry
Vehicles generate messages with a V2X software stack. It can run on a dedicated V2X OBU, a retrofitted on-board unit, but car manufacturers usually install it on their own electronic equipment.
V2X is like a heartbeat, vehicles typically send ten messages per second. These messages contain important parameters such as the accurate geographical location, the actual speed, velocity and direction of the vehicle, and the status of brakes and hazard warning lights.
Vehicles receiving V2X messages run applications based on this vast amount of information to display alerts of potential dangers. Messages can be read by all V2X-enabled vehicles, but only the relevant ones are used. In most cases, messages from a car on the other side of the highway are not useful from a safety point of view. Unless the data tells us that the vehicle is going off the road, possibly crossing our path.
Applications are divided into several categories according to their level of complexity.
- Day 1 applications includes basic awareness solutions, all of which are technically feasible today. These apps provide alerts about traffic jams, accidents, objects on the road, construction zones and poor weather or road conditions.
- Some of the more advanced Day 2 applications are still under development or finalization. One of the best-known Day 2 apps is platooning, which coordinates autonomous and cooperative driving of high-speed caravans of trucks to move efficiently.
Road safety applications use a dedicated radio frequency on the 5.9 GHz band, because life-saving V2X solutions require direct connection with low latency. Other information that is less sensitive to response time, such as weather and traffic conditions, can be shared over 4G or 5G connections.
The V2X RSU or roadside unit is an important part of the V2X ecosystem. It has its own processing power, sends and receives messages. An RSU also acts like a hub for roadside sensors: smart cameras, radars and lidars. These sensors are usually installed by the road infrastructure owner to look at the traffic – from a different angle than cars. RSUs play an important role in recognizing the unconnected traffic participants, particularly the vulnerable road users.
RSUs has the ability to forward traffic data to the Commsignia Central Data and Device Manager software to enable traffic managers visualizing road events on a map. Central can also be used for device maintenance and V2X message creation.
Several elements of traditional road infrastructure can be linked to the RSUs. For example, traffic light controllers can provide signal phase and timing information via V2X for trucks and normal passenger cars. Moreover, first responders, buses and urban maintenance fleets can even request priority at V2X-enabled intersections. In Denver, Colorado, snowplow trucks cross intersections by requesting a green light, causing less disruption to traffic.
V2X solutions are essential for self-driving vehicles, because messages contain more accurate information than the vehicle’s sensors can detect. In Las Vegas, self-driving taxis are receiving traffic light information from Commsignia RSUs to improve decision making and move through intersections faster.
Security in V2X solutions
The whole V2X system is built up in a way to prevent tracking and protect the users’ privacy. The messages don’t contain personally identifiable information.
The messaging is secure, authenticated by digital signatures. No one wants to see information in a car coming from unknown sources, just as we don’t want to receive spam, scam and phishing emails in our inbox.
Cars have certificates to prove their authenticity. They have thousands of certificates that frequently change to prevent tracking. The whole certification system has been built up in a way that no one entity, no one authority sees the whole picture. Those who roll out the certificates don’t know which car will get those certificates.