Using Amateur Bands for other purposes

Foundations of Amateur Radio

Recently I came across a series of strident posts about the injustice associated with a non-amateur service using the 70cm band. Complete with links to discussions, spectrum plots, angst and even incoherent outrage, all related to the notion that whomever "allowed" this user to transmit on this band was clearly incompetent.

Except, that this is probably not the case, or the full story.

So, what's going on and why are people incensed?

This all started at least six years ago. Since then AST SpaceMobile has deployed seven low Earth orbit satellites and used the 70cm band to communicate with them. Although in the trial phase, there's plans for an additional 243 satellites, and there's at least one other company playing in the same space, Atmos Space Cargo.

The outcry from amateurs is around the commercial use of "their" 70cm amateur band. It's an emotional statement, but what is the reality?

Before I dig in, let's set some terms. Radio frequencies are globally coordinated because electromagnetism doesn't care about sovereign borders. This coordination is conducted at the United Nations by a body called the ITU, the International Telecommunications Union. Within that body, amateur radio gets a seat at the table from an organisation called the IARU, the International Amateur Radio Union.

For the purposes of the ITU, the world is divided into three, Region 1, or essentially Europe, Russia and Africa, Region 2, the Americas and Greenland, and Region 3, the rest of the world. There's more to it, for example, Antarctica is split across all three, but for the moment, that really doesn't matter.

Of interest is that the band plan, the agreements that outline which frequencies are set aside for what service, might be defined differently across each of those three regions.

To add complexity, each country can be granted exceptions. I don't know the exact mechanics of how this is achieved, but I can guarantee that there's lots of haggling and foot stomping, diplomatically of course. If you're curious how I come to that observation, just look at the absurd list of exceptions associated with each band plan allocation.

Further complexity is added by the fact that not all allocations occupy the same frequency range. For example, in Region 1, the 2m band for Amateurs exists between 144 and 146 MHz, in Region 2 and 3 it's between 144 and 148 MHz.

Within an allocation there is the concept of shared and exclusive priorities. These determine who "wins" if two stations with a different service are transmitting on the same frequency. Essentially, a secondary user may not interfere with a primary user and a tertiary user may not interfere with either a secondary or a primary user and so on. A primary user can pretty much do what they want, as long as they stay within the allocation and don't interfere with other primary users. As a result, the order in which services are listed, matters. An exclusive allocation doesn't have to be shared at all.

Between regions these service priorities might not be the same. For example, in Region 1 between 430 and 432 MHz is allocated to Amateurs and Radio Location, but in Region 2 and 3 it's between Radio Location and Amateurs. So an amateur using that frequency whilst in Region 1 would be a primary user, but in Region 2 or 3 they wouldn't.

As an added wrinkle, for example in Australia, that slice is "primarily for the purposes of defence and national security", even though Radio Location is the primary service and Amateurs the secondary one. As a bonus, amateurs in Australia have access to 420.8 to 421.2 MHz as a secondary service, even though the ITU designates this as Fixed, then Mobile, except Aeronautical Mobile, and then Radio Location. Although amateurs are a secondary service, they come after the Department of Defence who are the primary users for those frequencies in Australia. Between 420 and 430 MHz, and from 440 to 450 MHz in several countries, Australia included, the Amateur Service is explicitly designated as a secondary service even though the band plan doesn't actually show this.

If you're confused, you're in good company, since this tapestry of regulation isn't as straightforward as the "70cm band is an amateur band", in fact, I'd go so far as to say that it's not an amateur band at all, except perhaps in Region 1 between 430 and 440 MHz where Amateur is designated as the non-exclusive primary service.

Back to the blow up.

AST was at one time authorised to use 430 to 440 MHz for trial purposes by a regulator in Region 2, the FCC, the United States Federal Communications Commission. I suspect that at the time, the Blue Walker 1 nano satellite was experimental and the approval made sense.

You can argue that whomever initially allowed this made a mistake, but, reality is whatever the regulator says it is, unless someone at the ITU objects.

It appears that the FCC has since been attempting