What is V2X Communication | V2X Enhancement, Release 18 V2X | Explained


When vehicles communicate with other vehicles to the infrastructure, to the pedestrians, or the mobile network, we call it Vehicle to Everything (V2X).

Imagine a typical urban environment with several road users, vehicles, road infrastructures, buildings, and cellular networks. All vehicles in this scenario may or may not have the capability or the modems to communicate wirelessly.

Having V2X module installed vehicles will communicate with each other, however, the wireless link directly or via cellular network to inform each other about their location, speed, heading direction, and any relevant warnings for collision mitigation.

V2X communication is a complete road safety and traffic efficiency solution that allows vehicles to communicate with their surrounding objects.

When we say vehicle we mean any motorized vehicle including cars, buses, trucks, ambulances, and motorbikes. Similarly, when we say pedestrian in general terms we refer to vulnerable road users that include pedestrians, cyclists, scooters riders, etc.

With the infrastructure, we mean smart traffic lights, road signs, and V2X roadside units and mobile networks can be 4G, 5G, or beyond that any of these cellular networks.

In the connectivity landscape, short-range communication vehicles and other road users often use direct communication with each other in an Ad-hoc manner, whereas for the long-range communication or Internet of Things (IoT) applications they rely on 4G and 5g cellular networks.


Ad-hock (Sidelink or PC5)

-Short-range (<1km)

-Direct communication

-Cellular based V2X (C-V2X PC5)

-Wi-Fi based V2X


Long-range V2X communication (Cellular Network (Uu))

-Long-range (>1km)

-Mobile Edge Support

-Guaranteed QoS

-Trust and Authentication


V2X communication of our cellular network uses a user interface which is commonly used in our mobile phones cellular networks bring additional benefits for redirects communication that includes mobilized computing support, Quality of Service (QoS) can also be corrected using the mobile networks.

Internet of Things (IoT) applications can also be supported to connect vehicles to smart homes and automated parking systems.


3GPP Release (Rel 18)

3GPP release 18 has enhancements for V2X technology and V2X stands for Vehicle to Everything, this is a communication between a vehicle and any entity that may affect or may not be affected by the vehicle.

This is a vehicle communication system that incorporates other types of communication like vehicle to infrastructure, vehicle to network, vehicle to vehicle, vehicle to pedestrian, vehicle to the device, and others, etc.

So, in the 3GPP release, there enhancements of this like various areas for the Rel 18 work is to enable such applications which require higher throughput and reliability.

-New Radio LTE (NR -  LTE) V2X Co-channel existence

-SL (Sidelink) positioning

-User Equipment (UE) scheduling another UE over Sidelink (SL)

-Carrier aggregation (multi-carrier)

-UE to UE relay


UE Scheduling Another UE over Sidelink

Use cases;

-RSU managing communications at an intersection

-Designated UE, e.g group leader

-The receiver UE scheduling transactions.

Scheduling over Sidelink compared to Mode 1 enables benefits even in out-of-coverage area scenarios and for UEs that do not have a Uu interface.

-It improves system reliability by reducing collisions caused by half-duplex and hidden nodes.

-Reduces power consumption of UEs (User Equipment) that no longer perform sensing.



-Leader selection and reselection

-Group management

-Scheduling mechanism


Sidelink CA (carrier Aggregation) for V2X

SL CA is supported for LTE V2X but is currently missing in NR V2X.

-This will allow improved performance in regions where the V2X spectrum is fragmented e.g. the EU and where there may be different channels for NR in the ITS spectrum.

-For advanced V2X services, more carriers are needed for higher data rate services, such as raw sensor data sharing.



-Enable CA for V2X services on contiguous and non-contiguous carriers that may span multiple bands

-Pre-(configured) mapping from application to the carrier

-Capability exchange for unicast connections


Sidelink UE-to-UE relay evolution

Extending UE-to-UE relay for advanced V2X use cases

-NLOS (Non-Line of Side) vehicles may experience a blockage.

-Road-Side Unit) at an interconnection can provide relaying to enhance reliability for cars NLOS to reach others.

-RSU may use network coding to improve resource utilization in high-reliability eV2X (Enhanced Vehicle to Vehicle) scenarios.



-Enhance Release 17 (Rel 17) UE-to-UE relay to support relaying for connection-less traffic.

-Network coding retransmission support by relay UE.



UE = User Equipment

Rel =Release

SL = Sidelink

V2X = Vehicle to Vehicle

LTE = Long Term Evolution

NR = New Radio

CA = carrier Aggregation

RSU = Road Side Unit

GPP = Generation Partnership Project.

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