Hi  @aaron_9511 

Here are some possible causes:

1. Signal Attenuation Due to Building Materials:

   • Modern buildings often use materials like concrete, steel, metal frames, and thick glass, which significantly weaken wireless signals (especially 2.4GHz/5GHz Wi-Fi).
   • For example, concrete walls and metal structures can reduce signal strength by over 20dB, causing a sharp drop in performance.

2. Signal Reflection and Multipath Interference:

   • Inside the building, multiple reflective surfaces (e.g., walls, metal furniture) can cause signals to arrive via different paths, leading to phase cancellation (multipath interference) and further degrading signal quality.

3. Frequency Band Interference:

   • The building may have other wireless devices (e.g., Wi-Fi networks, Bluetooth, microwaves) that interfere with the outdoor AP’s signal.

4. Distance and Free-Space Path Loss:

   • Although 20 meters seems closer, the signal must penetrate building obstacles, resulting in higher attenuation than in open-air conditions at 100 meters.

Please refer to the following to optimize the wifi signal of the EAP:

How to optimize wireless performance of EAP products