Starlink, shot by both sides in Ukrainian fracas, lives to fight on

Jam today, jam tomorrow?

Opinion On October 7, Ukrainian soldiers fighting on the front line reported outages on the Starlink satellite internet service. The outages were most notable in the southern Kherson region, where the most intense fighting was taking place.

Starlink is used for force command and communication, as well as relaying drone video for targeting decisions: the loss was described to the Financial Times as having a “catastrophic” impact on the rapid advances Ukrainian forces made at the time.

A few hours later, the service was restored. Since then, in the absence of an official narrative or credible evidence, intense speculation about the outage has split into the three main theories: Russian jamming, an unintentional Starlink issue, or deliberate disruption on the orders of Elon Musk.

If anything deserves to be jammed here, it’s Elon Musk’s mouth. His pronouncements are frequently contradictory, inflammatory, hasty and provocative. What they are not, absent verification, are authoritative. Of all the explanations, this is the most political. Let’s look first at the technical possibilities.

One plausible explanation is that Starlink wasn’t tracking the rapid advances of the Ukrainian counteroffensive, which moved into an area blocked by the service on the grounds of being Russian-occupied territory. Starlink certainly has and uses geo-location based area blocking to comply with national regulatory demands and service management. Yet Starlink knows the identity and location of each user terminal, and where the traffic goes: it most likely has one of the best dynamic pictures of the front line of any agency outside the Ukrainian military.

Jamming is at once the best understood and hardest to call possibility. The speed at which these latest outages were cleared is suggestive to some that it wasn’t jamming, as that couldn’t be mitigated so fast, but earlier in the conflict Starlink created some very rapid anti-jamming techniques. Electronic warfare in an active conflict evolves very quickly as each side reacts to the successes of the other: with Starlink, there’s lots for both sides to learn.

Put crudely, signal jamming works by putting enough of the wrong sort of radio energy into the receiver of your opponent to mask the signal they want to hear. Their job is to get more of their energy through: it’s a game of electromagnetic power.

The closer you can get to the enemy, the better – radio signals change strength according to the square of the distance they cover. With Starlink, the satellites at their closest are some 500km away (310 miles) from the user terminal. If the jammer can get within 5km (3.1 miles), or a hundred times nearer, they have an automatic ten thousand times power advantage. A small airborne pod, in a simple case, can drown out satellites much beefier than those Starlink employs.

The case isn’t simple. Starlink uses beamforming, a technique for creating electronically steerable beams of radio energy that can lock on to one or more satellites, shielding the channels to some extent from interference from different directions. In theory, this can be very effective, and Starlink has very good beamforming, but it is primarily a commercial system design down to a price and with performance a higher priority than jamming resistance. In particular, beams have sidelobes, directions in which they can leak and absorb off-beam energy, and this aspect of the system isn’t easy to characterise.

Plus, Starlink has three possible jamming vectors: the uplink, the downlink, and the GPS it uses to orient itself in space and time. Since the conflict started, Starlink could have, and almost certainly has, produced modulation schemes for hostile environments that trade off raw bandwidth for robustness: a narrower bandwidth rejects more noise, as do coding schemas that use statistical analysis to leverage redundancy.

Another anti-jamming option available to Starlink is to reprogram the network so that user terminals close to the front line can choose not to point to the closest satellites, which will be vertically above them and thus also closest to the opposition, but at those away from the front line, further away from where the jammers might be. If you point your beam away from an interference source, the less chance you have of picking them up. The disadvantages are that the satellites you talk to are a lot further away, thus you and they are weaker to each other, and their receiving beams are pointing much more towards potential jammers. Geometry can be an advantage, but not simply so.

Satellite broadband concept

Musk says Starlink will keep providing free service to Ukraine


This isn’t the first time commercial equipment has found itself in electronic conflict. In World War II, the British used hospital equipment and mothballed TV transmitters to block German bomber navigation aids, and Bosnia saw microwave ovens used to distract radar-seeking missiles. Starlink is, however, by far the most complex and tactically important.

Finally, jamming isn’t a switch, it’s degradation. It doesn’t have to be enemy action: physics doesn’t differentiate between friends, competition, or murderous invaders. Starlink itself says it is very vulnerable to interference from proposed expansion of 5G so any claims that it’s impossible to jam the service, or conversely that jamming will be hard to counter once it works, will need hard evidence to be credible. Hard evidence from active electronic conflicts between nationstates is too precious to spread around.

The final, most important, aspect of Starlink in Ukraine isn't technical, it's political. The immediate politics is that Starlink and its parent SpaceX are of great value to Ukraine, the US DoD and intelligence services, and their allies. Conversely, Starlink and SpaceX depend on the pleasure of American regulators like the FAA and FCC, who are in symbiosis with the US government's other agencies. It's not a consortium that invites freelance tampering per the Colonel Musk scuttlebut. This is the most important war for many decades, and Starlink is enmeshed at the highest level as one of the smallest players.  There are tensions aplenty – see the mid-October spat about who pays for what, where Musk said he was being short-changed by the Pentagon, then appeared shrugged it off the next day.

The longer term implications are even more intriguing. Starlink’s importance in the hottest of armed conflicts shows how far a modern commercial system can go, and how quickly. As new services line up that will look more and more like normal cell phone networks with normal handsets, the ability of authoritarian states like Iran, Russia and China to cut off insurrectional network access at will is increasingly at risk. As Russia is finding, that may not be so easily blocked. ®

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