From public charging stations at malls and highway travel stops to fleet charging depots at truck terminals and logistics parks, electric vehicle (EV) charging infrastructure is being deployed across a diverse range of environments. In all of these applications, wireless connectivity plays a fundamental role—not only by enabling remote diagnostics and transaction time-stamping but also by allowing autonomous vehicles (AVs) to download high-definition (HD) maps.
Currently, charger reliability remains a major industry pain point. A University of California study on public chargers in the San Francisco Bay Area found that only 72.5% were functional. A wireless network connection enables operators to remotely monitor, troubleshoot, and even repair equipment (such as via a remote reboot or patch download), thereby preventing lost business due to downtime. Furthermore, reliable connectivity ensures that chargers funded by the U.S. National Electric Vehicle Infrastructure (NEVI) Formula Program can meet the strict 97% uptime requirement.
Below is a detailed breakdown of how GNSS (Global Navigation Satellite System), Cellular (4G/5G), and Wi-Fi enable these applications, along with key considerations when selecting the right antenna for each technology.
1. GNSS: High-Precision Timing and Positioning
Even though EV charging stations are bolted to concrete bases and remain stationary, they rely heavily on GNSS for precise timing applications, such as generating secure time stamps for payment transactions.
Antenna Selection and Deployment Key Points
Patch Antennas: These are the ideal choice. Because charging stations are permanently mounted, it is easy to ensure the antenna has a clear, unobstructed view of the sky. Patch antennas support circular polarization, which perfectly matches the circularly polarized signals transmitted by satellites. Their high gain and stable phase center significantly maximize the performance and reliability of timing applications.
High-Precision Positioning (DGNSS/RTK): In specific scenarios—such as public transit buses that utilize overhead pantographs for charging—Differential GNSS (DGNSS) and Real-Time Kinematic (RTK) positioning technologies can achieve accuracy under 1 centimeter. This centimeter-level precision enables the vehicle's Advanced Driver-Assistance System (ADAS) to flawlessly guide and dock the bus with the pantograph, eliminating the physical damage caused when drivers misjudge maneuvers.
Environmental Protection and Interference Mitigation
Weather Resistance: Because charging station antennas face long-term exposure to the elements, they must feature an IP67-rated and UV-resistant enclosure.
Surge Protection: Lightning presents a significant risk for chargers lacking a protective canopy. Operators should look for models that comply with IEC 61000-4-5/Class 4 surge protection standards
Anti-Bird Perching: Perching birds can block satellite signals. To thwart this, choose an enclosure design or installation location that makes perching uncomfortable or inconvenient for birds.
2. Cellular (4G/5G): Region-Agnostic Broadband Connectivity
4G and 5G cellular networks offer a convenient way to provide charging stations with high-speed broadband connectivity, eliminating the need to run traditional Ethernet cables. In many remote locations, such as rural highway rest stops, cellular is often the only telecommunications network available. This connectivity is a critical backbone for U.S. government initiatives aiming to build public EV charging stations along interstates to mitigate the range anxiety that keeps consumers sticking to internal combustion engine (ICE) models.
Antenna Selection and Deployment Key Points
Band Compatibility: Unless a charger comes bundled with a specific wireless plan out of the box, it is impossible to predict which mobile operator will provide service once it is installed. Therefore, the antenna's band requirements must be determined by the specific frequencies supported by the charger’s internal cellular module.
Signal Coexistence and Mitigation: The cellular system must coexist peacefully with the charger’s own GNSS system. The GNSS antenna must feature exceptional out-of-band rejection capabilities. For instance, KEESUN antenna provides greater than 80 dB of rejection at commonly used LTE frequencies between 700 MHz and 1 GHz, and greater than 60 dB of rejection between 1820 MHz and 3500 MHz. This ensures that GNSS timing performance is not compromised, even when installed directly adjacent to an LTE transmitter and antenna.
3. Wi-Fi: High-Bandwidth and Fee-Free Complementary Connectivity
If a logistics park or travel stop already features extensive outdoor Wi-Fi coverage, Wi-Fi can serve as either the primary network or a redundant/fallback network to cellular. Additionally, Wi-Fi serves as an ideal bridge for vehicle-to-charger communications.
Core Application Scenarios
Massive Data Downloads (e.g., HD Maps): Fully autonomous EVs require incredibly detailed, high-resolution maps to ensure safety, and these map files are enormous. Utilizing the vehicle's charging window to download the next leg's map data over Wi-Fi perfectly avoids expensive cellular data fees.
Telematics Data Collection: Whether a vehicle is fully autonomous or has a human driver behind the wheel, pulling vehicle health and diagnostics data while it is parked at the charger helps fleet managers identify emerging problems before they escalate into costly repairs and extensive downtime. Compared to transmitting this data over cellular while on the road, utilizing Wi-Fi at the charger eliminates mobile carrier fees entirely.
