Fibre-Optic Drones Versus Electronic Warfare

One of the most striking developments of the war in Ukraine is also one of the oldest in concept: attack drones tethered to their operator by a fibre-optic cable unspooling in flight from a reel, with lengths that have grown from a few kilometres to around twenty. The reason for their appearance is simple: radio stopped being reliable.

The problem: a front saturated with jamming

A conventional FPV drone depends on two radio links, control and video, and in many cases also on a satellite signal for navigation. All three can be attacked. Electronic warfare systems deployed en masse by both sides emit noise on those bands to break the link or spoof the satellite navigation signal, with the result that a very high proportion of launched drones never reach their target. RUSI analyses published between 2023 and 2025 estimated monthly losses of small drones in the tens of thousands, with jamming as the main cause.

Layered on top of continuous jamming is the fear of an electromagnetic pulse, whether nuclear in origin or from high-power microwave weapons designed to disable the electronics of entire swarms. The cable does not protect against a pulse that hits the aircraft directly — the onboard electronics remain exposed — but it does protect against anything that attacks the communications channel.

What fibre solves

A fibre-optic cable does not radiate, cannot be jammed by radio noise, and does not reveal the operator's position through emissions. That changes three things at once. First, the video and control link becomes immune to jamming, allowing operation where no radio drone works. Second, the operator does not appear on direction-finding systems, which on the Ukrainian front have become the main threat to drone crews. Third, fibre offers excellent bandwidth and latency, with a clean picture even at low altitude and inside buildings or tunnels, where radio signals are lost.

The trade-off is just as concrete. The cable snags on trees, power lines and rubble; it restricts manoeuvring and largely rules out flying in tight circles; it adds reel weight that cuts payload and endurance; range is physically limited by the length carried; and the wire is left visible on the ground, allowing it to be traced back to the launch point. Operators themselves describe the system as a tool for specific missions, not a general substitute for the radio drone.

Other responses to jamming

Fibre is only one route. In parallel, narrow-beam antennas and frequency hopping have spread, making jamming harder without giving up radio; relay links using a second drone as an airborne repeater; and autonomous terminal guidance, in which the aircraft memorises the target's image over the final few hundred metres and completes the approach even if it loses the link. This last option is the one that raises most concern from a human-control standpoint, because it shifts part of the decision to the machine.

As for protecting the electronics themselves against pulses and jamming, the measures are classic and well known: shielding, filtering on power and antenna inputs, and redundancy. They are expensive and heavy, which explains their absence from cheap, disposable hardware.

A principle older than the current war

Guiding a weapon by cable is nothing new: wire-guided anti-tank missiles, from the Soviet Malyutka to the American TOW and the European MILAN, have been doing so since the 1960s, and wire-guided torpedoes predate them. What is new is the combination with high-definition video, lightweight reels carrying kilometres of fibre, and very low-cost platforms. The underlying logic holds: when the electromagnetic spectrum is contested, a physical transmission medium regains its full value.

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