====== Reception & Placement ======

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

===== Mounting position =====

  * **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.

===== Interference =====

  * 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).

===== Antennas & polarization =====

  * 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 [[en:hardware:antennas|External Antennas]].

===== Temperature =====

  * 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.

===== Outdoor installations =====

  * Use [[en:hardware:surge_protection|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 [[en:hardware:enclosure|enclosure]] in ASA so it is UV-resistant and waterproof, and use the supplied bottom seal and rubber plug for the LAN cable ([[en:getting_started|Getting Started]]).