Vehicle-to-Everything (V2X) technology refers to an intelligent transportation system where all road entities including vehicles, pedestrians, cycles, motorcycles, and infrastructure units are interconnected with each other. It has many subsets like V2V (Vehicle-to-Vehicle), V2I (Vehicle-to-Infrastructure), V2N (Vehicle-to-Network), and V2P (Vehicle-to-Pedestrian) communications.

Cars and vehicles, in general, were just dumb modes of transport not too long ago. They relied entirely on the driver to make all decisions like judging traffic or watching out for pedestrians. As a result, the possibility of human error was quite high. Moreover, inclement weather often led to erroneous decisions. As technology advanced and connectivity boomed, our vehicles also became smarter. Vehicles today have hundreds of sensors that give the driver useful information about traffic conditions, navigation assistance, or obstacle detection. It was only a matter of time before vehicles could communicate with each other.

All the above-mentioned subsets have different uses. One thing common is that all of them require a high-bandwidth, low-latency, and highly reliable network for secure communication.

Architecture of V2X

A basic V2X system will at least have the following three components:

• On-Board Unit (OBU): This unit is fitted in vehicles and it contains all the sensors and hardware that is needed for communication with other vehicles, persons, or infrastructure. For instance, it includes a transmitter and receiver and also a microcontroller/microprocessor unit to encode/decode all communication.
• Roadside Unit (RSU): This unit is installed on the side of the road. For instance, it could be located near a traffic light. It provides vehicles information about traffic conditions or nearby pedestrians.
• Central/Cloud Server: This server controls all roadside units and also has a record of all communication between vehicles and RSUs. Furthermore, in many cities, such central systems already exist to control traffic lights.

Another component of V2X technology could be the app that pedestrians use in V2P communication.

Why do we need V2X?

Vehicle-to-Vehicle (V2V) Communication

1.35 million people are killed in road accidents worldwide every year. Barring the accidents that take place due to mechanical faults, a majority of the accidents take place due to erroneous decisions on the drivers’ part. Imagine a scenario in which the sensors on-board the car can communicate with vehicles nearby. If the car ahead sees an obstacle and has to brake suddenly, the car behind can be notified of this and give the driver enough time to slow down. Vehicles can also communicate with each other to warn of road hazards.

A network of connected cars can help in optimizing routes thereby reducing travel time. This would save fuel as well as make road travel more convenient. There would be a reduction in road traffic. There are a lot of cases where ambulances have difficulty in reaching hospitals on time. With V2V technology, not only can the ambulance plan the shortest route beforehand but also the vehicles on the way can be notified of the ambulance and thereby make way for its quick passage. These are just some of the use cases of this technology.

Vehicle-to-Pedestrian (V2P) Communication

This is an exciting facet of V2X technology. A lot of research and simulations have been conducted already and the results are promising.

Most of us use our smartphones while walking down the street to buy groceries or grab a quick bite. We may be listening to music or texting someone. As a result, we may fail to notice oncoming vehicles while crossing the road. Before you proceed further, look at the number of fatalities due to Road Traffic Accidents mentioned above. Close to 20% of these fatalities include pedestrians or bicyclists.

Systems can be developed by combining V2P with V2I (Vehicle-to-Infrastructure) technology, where pedestrians or bicyclists are connected to traffic lights or a system at a crossing. Oncoming vehicles can be forewarned of pedestrians ahead and can make the necessary changes in speed well in advance. In case of blind spots in vehicles or when the vehicle is making a turn, the pedestrian can be notified of the same. In the case of distracted pedestrians, alerts to the phone can prevent them from coming directly in front of an approaching vehicle.

V2X is a technology that can be implemented using WLAN networks or using Cellular systems.

IEEE 802.11p – Dedicated Short-Range Communication (DSRC)

IEEE 802.11p is based on the IEEE Wireless Access in Vehicular Environments (IEEE WAVE) standard. It works in the 5.9 GHz unlicensed band for short-range communications. The protocol is specifically designed to work in fast-moving objects and enables reliable communication channels.

V2X originally used this standard as it was highly efficient even in Non-Line-of-Sight (NLOS) conditions. The subsets of V2X like V2V and V2I are based on this protocol. The United States’ Dedicated Short-Range Communication (DSRC) and the European Cooperative Intelligent Transport Systems’ (C-ITS) ITS-G5 initiative led to the first wave of V2X enabled vehicles.

IEEE 802.11p was characterized by the short-range (<1 km), low-latency (~2ms), and its high reliability. It is also designed to provide optimal performance in adverse weather conditions. However, a major drawback of this technology is that V2P communications cannot be implemented using this system. Also, it lacks scalability, Quality of Service (QoS), and offers intermittent connectivity in case of V2I communication.

Cellular-V2X (C-V2X)

We looked at the emergence of Cellular networks for IoT devices in a previous post. Similarly, Cellular networks are being hailed as the future of V2X technology. Instead of WLAN connections, vehicles will use the cell tower for communication. Direct communication between vehicles is also possible, through separate channels in the 5.9 GHz frequency band.

The 3rd Generation Partnership Project (3GPP) defined C-V2X in its release 14. Moreover, the 5G Automotive Association (5GAA) (comprising of tech giants like Qualcomm, Intel, Audi AG, etc.) has heavily invested in Cellular-V2X. 5GAA believes that C-V2X holds the key in the future of mobility and transport. Companies like Qualcomm have already come out with C-V2X chipsets.

The major advantage of C-V2X over 802.11p the extremely long range. Moreover, the Non-Line-of-Sight (NLOS) communication is far more reliable in the case of cellular networks. For instance, in Vehicle-to-Network (V2N) communications, the vehicle can easily connect with the central/cloud server for real-time traffic updates.

C-V2X also has flexibility. It has two basic modes of operation.

• Direct Communication includes V2V, V2I, and V2P without the involvement of a network. The devices are directly connected in the 5.9 GHz ITS (Intelligent Transport System) spectrum.
• Cellular Communication includes the cellular network infrastructure. Conventional mobile networks shall enable the vehicle to receive traffic information and alerts.

802.11p (DSRC) vs C-V2X – Which is better?

The United States has been a fertile ground for DSRC (802.11p). Many automakers like Toyota and General Motors have endorsed this standard. As a result, these companies have already rolled out vehicles with this technology in place.

Europe had earlier favored the 802.11p standard due to its availability for large-scale deployment. However, taking the emergence of C-V2X (5G networks specifically), they have shifted focus to C-V2X. Due to this strategic shift, the United States is also looking at the alternatives.

The major advantage of 802.11p is the fact that it is already in existence. All the infrastructure needed for large-scale deployment is already available. However, if we look at data from Gartner and other leading research companies, the number of 5G connections is expected to reach 65% of the world’s population by 2025. C-V2X is future-proof. Investing in 802.11p could lead to losses in the future when the technology might have to be replaced.

The following table shows a brief comparison between the two technologies:

What lies ahead for V2X?

China and a few other countries have pledged support for C-V2X. On the other hand, the United States is pushing for DSRC. Europe has adopted a slightly ambiguous approach. While they have endorsed DSRC, they recognize C-V2X as the future-proof technology. To this effect, European countries are trying to create technology that can be modified in the future to make use of cellular networks. As a result, OEMs are adopting a flexible approach by promoting different technologies in different markets.

SNS Telecom & IT predicts that by the end of 2022, V2X will account for a market worth $1.2 Billion, with an installed base of nearly 6 Million V2X-equipped vehicles worldwide.

Of these 6 million vehicles, about 70% are expected to have cellular technology. IEEE 802.11p is the incumbent technology. However, C-V2X is expected to replace it during this decade.

While the debate of DSRC versus C-V2X rages on, different carmakers will adopt different technologies. Whichever technology ultimately wins, connected cars will soon become a reality.

Fuel amounting to billions of dollars can be saved each year. As a result, the planet will become greener. Road Traffic Accidents (RTA) will go down drastically. The number of people losing their lives in such accidents will decrease. Traveling in adverse weather conditions will be much safer. This is what the future looks like if V2X technology becomes the standard.