Datalink

A datalink is the communications channel that binds an unmanned aircraft to its ground control station. It carries command and control traffic in one direction and telemetry, sensor video, and status in the other. Links range from short-range consumer radio protocols on FPV quadcopters, through directional line-of-sight microwave systems on tactical drones, to satellite links on long-endurance aircraft. Range, bandwidth, latency, and resistance to interference are the four properties that define a link's quality, and improving one usually costs another.

The link is the aircraft's longest lever and its greatest vulnerability. A drone with a jammed link is at best flying a pre-programmed fallback and at worst falling out of the sky, which is why electronic attack against command links is the most common counter-drone technique in current conflicts. Defensive measures include frequency hopping, directional antennas, mesh relays that extend range by bouncing the signal through other aircraft, and autonomous behaviors that reduce dependence on continuous control.

Link architecture also carries legal and ethical weight. A human-supervised strike through a datalink is the mechanism by which most armed forces keep a person in the decision loop for weapons release, so the reliability and latency of the link shape how autonomy is actually used in practice.