Radio technology fundamentals of V2V and V2X communication systems for autonomous vehicles

The revolution of autonomous transportation is not based solely on artificial intelligence, sensors, and processing algorithms. Equally crucial is communication between vehicles and their environment, known as V2V (Vehicle-to-Vehicle) and V2X (Vehicle-to-Everything) systems and their radio technology foundations. These technologies allow vehicles to exchange real-time data with each other, the infrastructure, pedestrians, and cloud-based control centers.

In this article, we present a detailed overview of how V2V and V2X systems work, their radio technology principles, frequency bands, protocols, challenges, and future development directions.

Why do we need V2V and V2X communication?

While autonomous vehicles use sensors such as radar, lidar, and cameras to perceive their immediate environment, many traffic situations exist where these sensors are not sufficient, for example:

• vehicles approaching from blind spots

• distant obstacles

• sensor limitations under adverse weather conditions

• traffic light status

• accident and congestion information

V2V and V2X systems help fill these blind spots by exchanging real-time data, significantly improving:

• traffic safety

• traffic efficiency

• environmental protection (through congestion reduction)

• reliability of autonomous decision-making

Components of the V2X system

V2X is a collective term encompassing multiple subsystems:

• V2V (Vehicle-to-Vehicle): communication between vehicles

• V2I (Vehicle-to-Infrastructure): communication with traffic infrastructure

• V2P (Vehicle-to-Pedestrian): communication with pedestrians and cyclists

• V2N (Vehicle-to-Network): communication via cloud-based networks

• V2D (Vehicle-to-Device): integration with onboard smart devices

The full V2X system acts as the nervous system of autonomous transportation.

Applied radio technology standards

Two major technology lines have developed globally for V2X implementation:

DSRC (dedicated short range communications)

• based on IEEE 802.11p standard

• direct vehicle-to-vehicle and vehicle-to-infrastructure links

• low latency

• frequency band: 5.850–5.925 GHz (USA), 5.875–5.905 GHz (EU)

• typical range: 300–500 meters

• data rate: 3–27 Mbps

Advantages:

• mature, reliable technology

• works independently of internet connection

• direct vehicle-to-vehicle communication

Disadvantages:

• limited bandwidth

• interference with other 5.9 GHz systems

• slower global adoption

C-V2X (cellular vehicle-to-everything)

• standardized from 3GPP Release 14

• based on LTE and 5G networks

• two modes: direct (PC5) and network (Uu)

Frequencies:

• 5.9 GHz (direct mode)

• cellular operator bands (network mode)

Advantages:

• higher bandwidth

• future-proof integration with 5G

• nationwide coverage through cellular networks

• better scalability

Disadvantages:

• network dependency for some applications

• higher initial costs

Technology comparison table

Radio technology challenges in V2V/V2X systems

The radio implementation of V2X systems faces several complex challenges:

Doppler effect

• high relative speeds cause frequency shifts

• particularly problematic for narrowband systems

Multipath propagation

• urban environments cause severe signal interference

• MIMO (multiple input multiple output) technologies are used to compensate

Interference management

• interference from other vehicles, infrastructure, or unintentional sources

• adaptive spectrum management is required

Spectrum allocation

• competition for the 5.9 GHz band (WIFI6, radar, etc.)

• ongoing negotiations among regulators worldwide

Data security and encryption

• public key infrastructure (PKI) systems

• real-time authentication

• adherence to data protection standards

Typical V2V and V2X applications

• collision avoidance in blind spots

• emergency braking warnings

• blind spot information sharing

• intersection traffic management

• dynamic speed regulation

• traffic light status communication

• weather and road condition sharing

• autonomous convoys (e.g., truck platooning)

The strong connection between 5G and V2X

5G mobile networks strongly support V2X development:

• ultra-low latency (URLLC)

• wideband sensor data transmission (massive MTC)

• dedicated network slices (network slicing)

• edge computing to further reduce latency

With widespread deployment of 5G standalone networks, V2X functions can reach full potential.

Future development directions

• 6G integration: terahertz communication, holographic radio

• cooperative autonomous driving: collaborative vehicle decision-making

• AI-based spectrum management

• quantum-proof data security

• ionospheric modeling for long-range V2X communication

Standardization and international organizations

• ETSI ITS-G5 (Europe)

• SAE J2735 (USA)

• 3GPP V2X Release 16-18 (global)

• IEEE 1609 (global V2X protocol stack)

Global interoperability is key for mass deployment of autonomous vehicles.

Frequently asked questions (FAQ)

Which technology will dominate?
Current trends favor C-V2X, especially with 5G and 6G integration.

What is the typical operating range?
Generally from 300 meters up to 1–2 kilometers depending on environment and application.

How secure are these systems?
PKI-based encryption provides strong security, but cybersecurity requires constant monitoring.

When will this become everyday reality?
The 2025–2030 period is likely for the mass rollout of V2X applications.