What are the three main characteristics that make wireless connections unreliable compared to wired links?

Path loss (signal weakens with distance), interference (other devices on the same frequency), and multipath propagation (reflections cause signal distortion).

1. Path loss (Pfadverlust):

• Signal strength decreases along the transmission path
• Fades gradually with distance
• Gets absorbed when passing through matter (walls, trees, rain)

2. Interference:

• Other radio sources on the same frequency band cause collisions
• Examples: other WLANs, Bluetooth devices, even microwave ovens (2.4 GHz!)
• Electromagnetic noise from motors and other electronics

3. Multipath propagation (Mehrwegeausbreitung):

• The signal bounces off buildings, the ground, and other surfaces
• Multiple copies of the signal arrive at the receiver at slightly different times
• These copies can constructively or destructively interfere with each other

These three factors together make wireless communication fundamentally more challenging than wired — even a simple point-to-point wireless link is harder than a cable.

Go deeper:

• Multipath propagation (Electronics Notes) — how the receiver sums the reflected copies, why it causes inter-symbol interference, and how MIMO turns it into an advantage.
• Multipath propagation (Wikipedia) — how reflected copies combine constructively/destructively to fade the signal.
• Path loss (Wikipedia) — the models for how signal power drops with distance and obstacles.