[solardev]

I just got my GPRS radio license and this was a really strange phenomenon to encounter. Apparently the FCC doesn't allow actual encrypted comms in this part of the spectrum, so the "privacy" codes, like you said, are really more just convenience codes, more noise cancelation than anything for privacy or security.

It was weird trying to explain this to my family, too. Basically just had to tell them "Nothing you say is private, and you should all say my call sign at the end of each transmission." We all felt like dorks, but it was super convenient in a place with no cell service.

[imroot]

Get an itinerant frequency -- $300, requires no coordination, and you can encrypt your comms.

One of the (ham) radio clubs that I'm a member of does this as a benefit for the group, and it's something that's nice to have: I can give my wife a radio and not worry about what she may or may not say if we have to take two separate cars when we road trip.

I've been meaning to do the process myself, but, I haven't had the time (and honestly, I'd want someone else to do the paperwork for me so I'm more likely to pay someone else to do it) recently, but, this might be the thing that prompts me to go and do it.

73 de K4IMW/WQZQ315

[vueko]

Interesting! I was under the impression that the FCC was actually somewhat strict about part 90.35 eligibility, in that you have to provide fairly detailed specifics of your business use case or how you fall under the various educational/nonprofit exemptions, and that if you told them you wanted it for personal use or supplied a thinly veiled excuse they'd tell you to get lost. Maybe that understanding is outdated. I can imagine a HAM club having an easier time justifying that than you would as a random individual.

[ac29]

You dont have to provide detailed specifics of your business use case, usually just a sentence is fine.

But 90.35 does not allow for individuals to be licensed for personal communications. My guess is that if a ham club is offering this to members, it is doing so as an educational institution, or a public safety organization. If the license is granted that way, using it for personal communications would be impermissible.

[philsnow]

I doubt that there are requirements on the number of members of a ham club, you could probably have a 1- or 2-member "club" for the adults in your household, right?

[ac29]

You can read the text of 90.35 here: https://www.law.cornell.edu/cfr/text/47/90.35

Could you get the FCC to grant you a license you if you say you have a 2 person organization in your house? Maybe, I'd even say its likely if you spent a few minutes to get an EIN before getting your FRN.

Does that make it legal to use a commercial license for personal use? No.

[kotaKat]

Is there an actual EASY guide to dealing with itinerant licensing? The FCC paperwork is beyond confusing to try to get a single itinerant freq.

[ac29]

I do these all the time for work, you can email me if you have a question. It takes about 15 minutes if you are familiar with the process.

Individuals using radios for personal use are not eligible for the types of licenses I am familiar with, though.

[wferrell]

Cool!

What sort of radio do you use?

My friend and I tried to do -- the two of us in different cars driving down the same stretch of highway this with GPRS radios and very quickly we were not able to pick up the other's broadcast. We assumed it was that we didn't have big enough antennas and were not using a repeater.

Note - others were driving we were each a passenger in our respective cars.

[solardev]

Did you have car mounted external antennas? I'm totally new to the hobby so I might be wrong here, but I believe the handheld units are kinda trapped in a Faraday cage if you use them inside the car. If you have the 20W+ mobile (not handheld) kind and mount it to an external antenna though, there should be enough range even just with GMRS as long as you're not on the other side of the mountain or something?

Edit: Sorry, it's GMRS, not GPRS (facepalm)

[wferrell]

We were not using car mounted antennas. We will try this next time!

[ac29]

> Get an itinerant frequency -- $300

FCC fees are actually only $205. I do these all the time for work.

Also, you can get multiple frequencies on the same license, and you should if you are getting itinerants because there are so few and they are heavily shared.

The application takes around 15 mins if you're familiar with it and can be done completely online. If you've never done it before, it might take you an hour or more to figure out.

All that being said, the itinerants I am familiar with are in part 90 and that is only for commercial use. Its not clear to me that an individual would be eligible for this type of license for personal communications.

[eternityforest]

What about Meshtastic and CB? CB is kind of awful but it's cheap, and Meshtastic is text only but has amazing range.

I still can't believe any of this is even an issue though.

There's no technical reason we couldn't have cheap all digital bubble pack radios with miles of range and mesh support, running deep learning codecs on an ASIC or something....

Every time I'm on a project that needs radios it's an expensive hassle that seems like it should have been solved by now.

[solardev]

CB doesn't seem to solve anything that FRS (walkie talkies) or GMRS (nicer walkie talkies with call signs) doesn't already do better. Meshtastic is interesting but not for the use case of general use between family members (no way I want to build and support DIY hardware like that just to use as walkie talkies... GMRS radios are complicated enough already for the average non techie user).

It's so bizarre coming into the radio world from the tech/web/network protocols world. On one hand everything is so nicely defined and regulated and licensed and shared. On the other hand all the UX seems 20 years in the past.

I'm excited about things like DMR and handheld to handheld texting, but that's a harder license to get and there's only one expensive handheld that actually supports the texting, I think...

[eternityforest]

There's starting to be off the shelf Meshtastic hardware, otherwise I'd agree.

Actually using custom hardware or soft is not something I consider a reasonable choice, basically ever, unless there's no off the shelf alternative, or I'm specifically being paid to create said off the shelf alternative.

CB has a bit better range but otherwise I'd mostly agree.

In practice FRS is the only thing I ever actually use besides checking in at the weekly net with a Baofeng, it's just the standard everywhere, even for small scale commerical stuff, and it's what everyone I know already has.

[solardev]

Is there no license available for private (doesn't have to be encrypted per se, just don't want to spam the whole channel) comms for general individual/family use?

I'm not discussing anything secret, just making breakfast plans etc, but having to try to find a quiet channel every time is such a pain...

[Aloha]

I'm using EFJ 5100's and have a full KVL, and software that can make Christmas Tree radios.

P25 Encryption is pretty good, in terms of quality.

[vueko]

While definitely better than the non-encryption of CTCSS etc, P25 encryption has some relatively concerning implementation problems. It's possible none of these actually matter for your usecase as many are related to UX around configuring and using encryption in an institutional setting, but the unauthenticated traffic injection, induced transmission and jamming issues are, well, not great no matter how you look at it.

https://www.mattblaze.org/blog/p25

https://www.mattblaze.org/papers/p25sec.pdf

I will grant that the open-source kfdtool keyloader boxes are neat.

I have been meaning to see if I can repro the induced transmission via retransmission requests thing when the data packet stuff is fully disabled via CPS, but a friend permanently borrowed my hackrf so that project is on hold for now. I'm not optimistic, though, due to the comments in the paper about where in the stack the retransmission request is processed.

[Aloha]

A lot of these issues if not all are specific P1 P25, which if you're on conventional you're using. I find it interesting they treat P1 as if it's different from normal FM, it is not, its C4FM - so all the normal capture effect stuff works fine.

In the end, the goal of P25 was to make it almost, but not completely possible to listen in - I'd also note the way they did their testing is not how these radios are typically deployed, which is not direct subscriber to subscriber on simplex, its either via a conventional repeated system or via a trunked system.

I do agree that frequent key changes are bad - but for entirely different reason, they're an operation nightmare. Most agencies who deploy it either use very long lived keys deployed by KVL, or deploy a UKEK and then change keys via OTAR on some cycle, which is not infrequently, never.

My belief is the theoretical risks on P25 are not well proven in reality, you're more likely to have some interference issue over say, intentional jamming.

Either way a radio for ~75 bucks plus supporting hardware that will do AES256 isnt bad - and DES-OFB/DES-XL is good enough to keep the casual listener out, which is more or less the point of the crypto here. Also I know they make a big deal about unit ID's, but they carry no meaningful info, its just a hex ID.