C-ITS can only be received over a few hundred meters up to a few kilometers, so receiver placement makes a big difference.

• The higher, the better. With the 3D-printed enclosure, the receiver board can be mounted outdoors.
• Outdoors beats indoors. Windows — especially tinted / coated ones — reflect the 5.9 GHz signal. If you must stay indoors, place the node directly at a plain window facing the road.
• A free line of sight towards roads, intersections, or tram lines gives the best results.

• A 5 GHz WLAN access point nearby can degrade reception — separate the devices or disable the 5 GHz band (the ESP32 itself only uses its radio for C-ITS; the official node has no WiFi anyway).

• The integrated PCB antenna of the ESP32-C5-WROOM module already performs very well.
• If you use an external antenna (u.FL variant), vertical polarization performs clearly better than horizontal — see the measurements on External Antennas.

• A typical operating temperature is about 55°C; in direct summer sunlight more than 83°C has been observed.
• Reduce the LED brightness in the self-service portal (0 = off, 255 = maximum) — the status LEDs at full power add noticeable heat.
• Prefer a shaded mounting spot for outdoor installations.

• Use surge protection when the LAN cable of an outdoor node runs to a switch indoors — one inline surge protector per outdoor run, properly grounded.
• Print the enclosure in ASA so it is UV-resistant and waterproof, and use the supplied bottom seal and rubber plug for the LAN cable (Getting Started).