Fibers.

This is coolbert:

UAV Russian impervious to jamming.

Fiber optic link!

"Russians have started using drones with fiber optic cables"

From Army Recognition ^ | 3/8/24 | the tip from Freeper.

According to a Telegram channel (@serhii_flash), the Russian military has begun deploying FPV (First Person View) drones equipped with coils of fiber optic cables, marking a significant advancement in drone communication technologies. The Ukrainian military has encountered one of these unusual drones, which had a 10-kilometer [about six miles] length of fiber optic cable unspooled during flight. 

Drone relying on on a fiber optic wire connecting the operator to the drone. Radio-frequency [RF] command link eschewed! Too susceptible to RF jamming that solution fiber optics.

coolbert.