The short version

• Orbital slots and spectrum are not owned. They are recorded, and the record is held by the ITU Radiocommunication Bureau.
• A filing has to be brought into use within seven years, and for both GSO and NGSO that means a satellite maintained on the notified assignment for 90 continuous days.
• Since WRC-19, NGSO constellations also face milestones of 10, 50 and 100 percent deployment at two, five and seven years after that.
• Missing a milestone does not cancel the filing. It shrinks it, which is the ITU’s answer to paper constellations.

Every satellite communications business rests on two assets it does not own. A position in the sky and a slice of spectrum. Neither is property. Both are entries in an international register maintained by the ITU Radiocommunication Bureau in Geneva, and the entries are made by national administrations, not by companies.

That structure explains a lot of behaviour that otherwise looks strange, including why an operator with no obvious connection to a small state files through it.

The filing chain

The process runs through the Radio Regulations, principally Article 9 for coordination and Article 11 for notification.

Advance Publication Information

Historically the first step, in which an administration told the Bureau what it intended to operate and the Bureau published it. Since WRC-19 the API stage was largely folded into the coordination request for most fixed satellite, broadcasting satellite and mobile satellite filings, so in practice most commercial systems now start at coordination.

Coordination request

Filed under RR No. 9.30. The Bureau publishes the request, identifies which administrations may be affected, and the notifying administration then has to coordinate bilaterally with each of them. This is where most of the time and most of the negotiation goes. There is no arbitrator. If two administrations cannot agree, the filing sits.

Notification and recording

The assignment is notified to the Bureau, examined for conformity with the Table of Frequency Allocations and the applicable coordination, and if the finding is favourable, recorded in the Master International Frequency Register. Recording is what confers the right to international recognition and protection from harmful interference.

Bringing into use

The assignment must be brought into use within seven years of receipt of the complete coordination request. Miss it and the filing is cancelled.

For a geostationary network, bringing into use means a space station with the capability to transmit or receive on the notified frequency, maintained at the notified orbital position, for a continuous 90 day period. For a non-geostationary system, it means deploying a satellite in one of the notified orbital planes and maintaining it for 90 continuous days.

The problem with 90 days and one satellite

Read the NGSO rule again. One satellite, 90 days, and a filing for a constellation of ten thousand is brought into use.

That was the position before 2019, and it produced exactly the behaviour you would expect. Filings for enormous constellations were made and held with minimal deployment, blocking coordination for anyone who came later. The industry term is paper satellites.

WRC-19 fixed it with Resolution 35, which added a milestone based deployment schedule measured from the end of the seven year bringing into use period.

Administrations must report deployment to the Bureau no later than 90 days after each milestone period expires.

The sanction is elegant. It is not cancellation. It is automatic reduction of the recorded satellite count. Fall short of the 10 percent milestone and the filing is capped at ten times the number actually deployed. Fall short of the 50 percent milestone and it is capped at twice the number deployed. Fall short at 100 percent and it is capped at exactly what is flying.

An operator that files for 10,000 and deploys 400 by milestone one keeps a filing for 4,000, not 10,000. The paper constellation shrinks to the size of the real one.

Why the flag state question arises

Filings are made by administrations. A company does not file. It asks a national administration to file on its behalf, and that administration then bears the coordination workload and any international consequences.

Administrations differ in how quickly they file, what they charge, how they prioritise between competing domestic applicants, and how vigorously they coordinate. Those differences are real and they are a legitimate factor in structuring, in the same way that vessel registration is in shipping.

They also feed the criticism that the system rewards administrative arbitrage rather than technical merit. That criticism has not produced a change in the rules, because the rules are made by the same administrations.

WRC-23 and what is coming at WRC-27

WRC-23 ran in Dubai from 20 November to 15 December 2023, with roughly 3,900 delegates from 163 Member States. Three outcomes matter for NGSO operators.

New orbital tolerances were introduced. For systems with eccentricity below 0.5 and apogee under 15,000 km, apogee, perigee and inclination tolerances are 70 km during deployment, tightening to 30 km afterwards.

A regulatory framework for Ka-band satellite to satellite links was approved, which lets LEO constellations relay through GSO and MEO systems.

On sustainability, the Radiocommunication Assembly adopted Resolution ITU-R 74 on sustainable use of spectrum and orbital resources, and the ITU began requesting post-mission disposal information from NGSO operators.

The flashpoint was equivalent power flux density. NGSO operators wanted a WRC-27 agenda item to revisit the EPFD limits that protect GSO networks, which date from a period when the NGSO population was tiny. GSO operators and several administrations opposed. EPFD revision was kept off the WRC-27 agenda, with technical studies continuing for a report without regulatory action.

For WRC-27, the items to watch are:

• AI 1.5, measures to limit unauthorised operation of NGSO earth stations and to allow a country to be excluded from an NGSO system’s service area. Both are technically contested.
• AI 1.16, NGSO interference into radio astronomy, including possible recognition of radio quiet zones for ALMA in Chile and the SKA in South Africa. This is now the main dark and quiet skies battleground inside the ITU.
• AI 1.12 to 1.14, new mobile satellite allocations including direct to device.

The gap the ITU does not fill

It is worth being clear about what this system does and does not do. The ITU allocates and records spectrum and orbital positions. It does not license satellites, it does not regulate debris, it does not adjudicate collisions and it has no enforcement arm.

An operator with a perfect ITU filing and no national authorisation cannot launch. An operator with both can still create a hazard nobody has authority to stop. That gap is the subject of our piece on space traffic management.