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The 2027 World Radiocommunication Conference will decide items that touch non-geostationary systems directly: sharing between NGSO and GSO networks in the Ka-band, spectrum identification for direct-to-device and non-terrestrial networks, and protections for Earth exploration services. The decisions are made in November 2027. The radios being designed now will fly under them.

For hardware teams the questions are concrete. The FCC retired its equivalent power flux density limits in April 2026 in favor of throughput-based protection criteria, but the ITU limits still apply everywhere else, so an antenna has to satisfy both: sidelobe control, power management, and beam steering that is designed in, not tuned later. Band plans that move by a few hundred megahertz change filter designs and frequency agility requirements. A D2D payload built for one L-band or S-band assumption may need another.

The regulatory team should be handing the engineering team a list of the agenda items that could move their design, with a decision date and a design freeze date next to each. If the design freeze comes before the decision, the team needs to know that now.

In May 2025 the FCC opened a proceeding to make more than 20,000 MHz available for satellite communications across four bands: 12.7-13.25 GHz, 42.0-42.5 GHz, 51.4-52.4 GHz, and four segments of the W-band between 92 and 114.25 GHz. That is more spectrum than satellite broadband can use today, and it is not all the same kind of spectrum.

The 12.7 GHz band sits next to the Ku-band downlinks every NGSO system already uses; removing footnotes NG52 and NG57 would make it the easiest capacity to add, subject to the terrestrial studies that were already under way. The 42 GHz band is unoccupied and pairs naturally with V-band downlinks at 37.5-42 GHz, and 51.4-52.4 GHz gives V-band systems an uplink pair. The W-band segments are a different proposition: path loss is 15 dB higher than at Ka-band before rain is counted, and the passive services between the segments set emission limits that shape the antenna.

For an operator, the useful exercise is to run the frequency plan through each band with the capacity and rain-fade numbers, decide which bands the business case can close on, and say so in the docket with the exhibits attached. The comments that shaped the last sharing rule were the ones with calculations attached.

The FCC's post-mission disposal rule is one sentence: satellites ending their mission in or passing through low Earth orbit below 2,000 km must deorbit within five years. Operators tend to hand it to the regulatory team. It belongs with the propulsion and structures leads.

At 550 km a mid-size spacecraft with a modest area-to-mass ratio decays naturally in about five years at mean solar activity, and in far longer at solar minimum. Above 600 km, passive decay does not meet the rule for most designs. That means propellant reserved for a disposal burn, a drag device that has to deploy after years in vacuum, or an orbit choice made early enough to avoid the problem.

The engineering consequences follow: end-of-life reliability of the propulsion system, passivation, a ballistic coefficient the operator can predict, and a disposal plan that satisfies both the licensing engineer and the insurer. The deorbit estimator on the Tools page gives the first numbers.

Every satellite needs a command uplink and a telemetry downlink, and most small operators put them in the S-band space operation allocations at 2025-2110 MHz and 2200-2290 MHz, the same bands the space and meteorological agencies have used for decades. A November 2023 ITU News piece by Jean Pla of CNES explains why coordination in these bands has become slower and what a filing should contain to move through it. The points below expand on that piece for a US operator.

Coordination is the Article 9 process by which administrations exchange the parameters of new and existing frequency assignments, study the interference between them, and agree on conditions before an assignment is notified and recorded under Article 11. It is mandatory for geostationary networks, for the fixed-satellite and broadcasting-satellite services, and wherever a footnote to the Table of Frequency Allocations requires it. For non-geostationary systems in the other services, including space operation and Earth exploration, the requirement is advance publication: the API is circulated in the BR IFIC, other administrations comment under Nos. 9.3 and 9.4, and the notifying administration has to resolve those comments. Non-mandatory is not the same as easy.

The problem Pla describes is generic filings. A growing share of S-band APIs book the entire 2025-2110 MHz and 2200-2290 MHz bands, declare the whole surface of the Earth as the service area, and list only typical earth stations rather than real ones. The Radiocommunication Bureau cannot reject a filing that complies with the Regulations, so the other administrations either answer with equally generic comments or ask for the missing detail, and the process lengthens for everyone. WRC-23 took the issue up under agenda item 9.2, and the CPM Report for that conference told administrations what a usable S-band API looks like.

The practical answer is specificity. File the center frequencies and bandwidths the spacecraft will use, not the band edges. Name the ground stations, or the commercial ground network, with coordinates. State the EIRP and the emission mask. Follow the Space Frequency Coordination Group recommendations on S-band channelization and bandwidth, and the protection provisions of ITU-R SA.1154 for the 2 GHz bands. Cite ITU-R SA.364 for the research and small-satellite frequencies. A filing built this way draws fewer comments and answers the ones it draws.

The higher bands behave differently. In the X-band, where 8025-8400 MHz carries Earth exploration downlinks at high data rates, coexistence between co-frequency networks usually requires calculations against the power flux density limits toward the ground rather than an exchange of letters. In the Ka-band, 25.5-27 GHz is where the highest-rate Earth observation downlinks are heading, and the coordination workload will follow them there.

For a US-licensed system there is a second layer. The FCC forwards the ITU filings, but the S-band space operation bands are federal in the United States, so commercial command and telemetry there is authorized case by case through FCC waivers with NTIA coordination. That review asks the same questions the ITU process does: which frequencies, which stations, how much power, and what protection for the incumbents. A filing that answers them once answers them for both.

Source: Jean Pla, "Frequency coordination for satellite radio services in S, X and Ka bands," ITU News Magazine, November 7, 2023.