[Aloha]

There is nothing in Part 90 that prevents a multi-band device, Motorola, Harris and Kenwood both sell multiband P25 devices (V/U, U/800, V/LTE, et al). Motorola, Harris and Kenwood (tait as well) also support multiple trunking/signaling systems on the same device as well.

What you're running into is agencies not wanting to interop - GMRS is a special case, because its a licensed by rule service (Part 95), but everything else, everything public safety and commercial can all be loaded in one radio, legally and technically (GMRS will technically work, its just not strictly legal - but the rules for Part 95 are widely flouted) - it takes agencies buying multiband radios (they're expensive) - and agencies willing to cooperate to share system keys (and encryption keys) which they loathe to do, because it means giving up control.

Interoperability is a huge issue with public safety, and it wont be fixed by broadband, it will only be fixed when a bunch of people die directly because of it, and then the public demand something be done - these agencies have no incentive to cooperate (quite the opposite, they might get less funding if they did).

[rsync]

Yes, there are multi-frequency devices, but they are all in the same "range" or "band" or "grouping" of frequencies (whatever it is we're calling that).

I'm talking about a combination hi-band, lo-band, GMRS, P25, paging, etc. radio. I should be able to tune National Weather Service on it if I want to.

When I talk about this, ham guys get all huffy about FCC this and that and what kind of anarchy do I want to live in. Whatever.

What I am telling you is that, on the ground, it's a shitshow (with regard to physical radios) and it's frustrating to know that it's a political problem, not a technical one.

[Aloha]

You can order a radio with High VHF, UHF, 700/800, 900, LTE or with any of the two above, Harris has the (it does something we affectionately call DC-Daylight - aka, the entire EM spectrum), SG-XG100 I think does basically everything, 30MHz to 1000MHz.

Low Band is a special case, because of the sheer antenna size, which is huge, and unwieldily low band handhelds are also near useless.

Ignore the ham guys, they dont know much about part 90 (other than they are correct that the Baofeng Radios are probably not type accepted.).

[schoolornot]

It doesn’t help that the protocols are all proprietary and/or encumbered with patents. An open source version of Brandmeister would go a long, long, way.

[Aloha]

None of the protocols are encumbered, P25 and DMR are both open standards - the audio codecs they use however, are not.

Brandmeister wouldn't fix anything in the public safety space as nothing in public safety is DMR.