C-V2X (Cellular Vehicle-to-Everything):

C-V2X is the latest implementation technology that is gaining traction in V2X deployments. It leverages existing cellular networks (LTE and 5G) for data traffic, making use of 3GPP cellular communication standards extended for V2X applications. C-V2X operates mainly on the 5.9 GHz band, although lower frequencies (around 3.4 GHz) are also explored for better range. C-V2X supports both short-range and long-range communication, utilizing specific control channels within the LTE network dedicated to V2X communication, to ensure lower latency for safety-critical applications. This is achieved through the PC5 interface (Proximity-based Communication) which facilitates direct communication between vehicles and RSUs without necessarily relying on the cellular core network. Due to multi-channel usage, simultaneous communication is allowed (cars do not need to transmit one at a time), but this may cause packet collision problems, requiring larger bandwidth to reduce package loss. While LTE C-V2X makes use of already existent infrastructure, for 5G, a dedicated infrastructure needs to be developed, requiring adaptation of existing cellular standards for V2X communication. Higher latency may be experienced when compared to DSRC due to reliance on cellular network traffic.

ANTENNAS

Cellular V2X (C-V2X) RSUs – Cellular Antennas:

• Directional antennas are commonly used for C-V2X communication as they offer high gain and focus the signal in specific sectors. This allows RSUs to efficiently communicate with vehicles within their designated coverage area. They typically operate in the cellular frequency bands used for LTE-V2X (around 600 MHz to 3.5 GHz) and potentially 5G NR-V2X frequencies (in the mmWave range) in the future.
• Omni-Directional antennas are used in some cases, particularly for smaller coverage areas or when 360-degree communication is desired. However, compared to directional antennas, they offer lower gain and might require higher transmitter power to achieve the same coverage range.

DSRC RSUs Antennas – Wi-Fi Antennas:

• Directional Patch Antennas: These flat, directional antennas are commonly used for DSRC communication due to their efficiency in the 5.9 GHz spectrum band allocated for DSRC. They offer moderate gain and can be oriented to focus communication towards specific areas like lanes of traffic.
• Omni-Directional Dipole Antennas: For short-range, omnidirectional DSRC communication, dipole antennas can be used. These simple antennas offer lower gain but radiate signals in all directions, potentially suitable for smaller intersections. These are suitable for small intersections for example.

Common Antenna Connectors for V2X applications

Cellular V2X (C-V2X):

• N-Type connectors: Threaded connectors for outdoor applications, weatherproof, handle higher power levels (suitable for various LTE bands).
• SMA connectors: Smaller screw-on connectors for test purposes or lower power RSUs.
• 4.3-10 connectors: Designed for 5G NR applications, might become more prevalent for C-V2X.

DSRC:

• RP-SMA connectors: Commonly used for DSRC applications, weatherproof, suitable for the 5.9 GHz band.
• MMCX connectors: Miniature coax connectors for DSRC antennas with smaller footprints, but may not be ideal for outdoor applications due to lower power handling.

Reliable communication is fundamental to the success of both DSRC and Cellular V2X technologies, facilitating crucial data exchange between vehicles, infrastructure, and pedestrians. By using the correct antenna and deploying it correctly you can significantly enhance the performance of V2X systems, ultimately driving forward the future of connected and safer transportation. As V2X technology continues to evolve, the role of advanced antennas will remain central to achieving its full potential.