
Amateur Radio Universal Text Messaging/Contact Initiative - Cieplak
http://www.aprs.org/aprs-messaging.html
======
chrissnell
APRS messaging is awesome. In many cases, you can leverage iGates and the
Internet-based APRS-IS backbone to move your messages from RF (radio) to
Internet and then back on to RF at a remote location.

I've built an APRS library for Go as part of a high-altitude balloon project
that I've been working on. It can encode and decode APRS messages, ACK
received messages, and send/receive APRS packets over AX.25/KISS (over serial
or TCP/IP). The library is currently bundled with the balloon code but I plan
on breaking it out into its own project soon.

Code here:

APRS library:
[https://github.com/chrissnell/GoBalloon/tree/master/aprs](https://github.com/chrissnell/GoBalloon/tree/master/aprs)

AX.25 encoding/decoding:
[https://github.com/chrissnell/GoBalloon/tree/master/ax25](https://github.com/chrissnell/GoBalloon/tree/master/ax25)

APRS-IS library (thanks to @dustin):
[https://github.com/chrissnell/GoBalloon/tree/master/aprsis](https://github.com/chrissnell/GoBalloon/tree/master/aprsis)

------
VLM
Spam problems?

This will sound heretical but I simply don't want push mode text. What it
fixes will be smaller than what it screws up.

A quarter century ago I was heavily into ham radio packet BBS systems (and
also node hopping or node dxing or whatever its called) and before internet
spam was a problem we had pbbs spam. I remember the first cantor and siegel
usenet spam in 93 or so... Anyway packet bbs spam was "its free to send the
entire planet a forsale offer to sell my worn out beaten up dented HT for $5
less than a new one (plus $10 shipping). So why not. In fact why not send my
sale notice every freaking 6 hours. For weeks." Or the ever popular "Rusty
abused slightly bent rohn 25 tower section in the middle of nowhere, you ship
it, $5 less than a new one" or "Willing to trade broken 1975 crystalized FM 2M
mobile rig (worth about $10) for brand new icom IC781 (worth at the time about
$8K), serious offers only pse 73".

I actually read every PBBS post that went thru the forwarding network until
1991 or so when some categorization scheme was introduced and I could start
ignoring forsale posts. Also traffic levels rose over the years.

Another awesome one was back in the early ka9q nos era you'd have people
spamming literally the entire planet because they couldn't bother reading the
manual to figure out how to calculate an IP netmask, or for the entire era
couldn't be bothered to glance at their radio's programming manual so why not
just bug 100K people instead.

Anyway, yeah, spam, I'm not imagining things would improve on the spam front,
nor is there apparently any technological ideas to fix it.

If you implement a tech thats free to push to a lot of people more or less
anonymously, you're going to end up with a steaming pool of spam and no users
soon enough.

Finally a huge PBBS problem from a quarter century ago was the proverbial
frequency cops would turn into a total PITA with respect to censorship. Its
not enough that they felt the need to interpret the regs their way, but god
help the souls of anyone else in the world who doesn't interpret the regs the
same way. The little old lady busybodies of ham radio. Anyway their attempts
to "fix" the spam problems tended to only make things worse. In fact they made
things dramatically worse in some areas. Which from their own troll-ish
viewpoint was likely a big win. So how is this push tech going to work around
both direct and meta-level trolls, which were a huge problem 25 years ago.

~~~
warble
Your concerns are well founded, but for point to point, especially combined
with any identity fingerprinting (public keys, etc..) would have none of these
problems.

If your network is going to broadcast though to many recipients, shaming is
about the only way to reduce this. Making sure the sender is who they say they
are is very important as well (like it is with email), but I wouldn't suggest
it would be successful in making it go away.

Once you start identifying senders explicitly, then circles of nodes can be
established that can limit entrance and or ostracise people who are annoying.
You have to attach cost to messaging in order to senders to value their
message, and other than charging a real amount of money which is probably not
a good idea, cultural and social costs are very important in establishing
trust and getting people to think more when they send.

Fortunately humans have been doing this for 1000's of years, so if you put all
the pieces there, it should work fairly naturally.

~~~
VLM
Despite all the tools being available, none of those social pressure effects
came into play 25 years ago.

Even worse, the few people who ran pbbs'es who felt like gatekeepering and
filtering generally made things worse rather than better. The usual social
effect of only giving power to the extremists with the strongest feelings.

There wasn't much if any problems 25 yrs ago on pbbs systems that would be
fixed by cryptographic identity proofs. In fact I can't remember a problem
like that ever having happened.

The very problem with the 1000s of years thing is the "tribe" 8000 years ago
was like 10-100 people, but the "tribe" on the worldwide pbbs network got to
tens of thousands and collapsed as it expanded. So the "solution" to "fix"
multiple small stable current day subnetworks is to merge and interop them
together until there's one big tribe that naturally will collapse just like
pbbs behavior, or for that matter landline modem bbs behavior or usenet or
many other examples.

The fundamental problem of using computers as socialization tools is their
tech scales with tribe size a lot better than interpersonal relationships. And
it doesn't seem to vary much with culture unlike virtually everything else. It
may be a truth there is no way to have a stable "tribe" of 100K users, no
matter what technology may permit.

~~~
warble
Point taken about tribe size.

Remembering the BBS days, the only troubles we experienced were on the bigger
systems where it became impractical to vet users consistently. Newsgroups that
were closed membership worked much better than open ones.

Cryptographic identity makes this easier to handle, but it's not the only way.
For example, on a system the size of Facebook, the only one spamming me is
Facebook. This is because of the social nature of my group. I know everyone
(more or less) and can kick them if need be.

The spammers have to pay to play, which unfortunately isn't keeping it down to
0 on Facebook, but probably less than it would be normally.

------
fidotron
One of the coolest things about APRS is the ISS has a beacon on it, so you can
bounce messages to and from space using not much more than a handheld and a
yagi.

The more extreme space bouncing is "moonbounce" where the moon is used as a
communications satellite, but that's not APRS, and certainly not doable with
small equipment.

------
superuser2
This is cool, but since all forms of encryption are prohibited on amateur
radio frequencies, not the most practical.

~~~
tlrobinson
(FYI, I believe encryption is forbidden, but digital signatures are ok)

~~~
a-priori
The rules vary by country. In the US, the FCC has prohibited amateur stations
from using encryption intended to 'obscure the meaning' of a transmission.
It's a grey area whether you're permitted to encrypt something for other
purposes. This permits digital signatures, since they do not obscure anything.

In Canada, the Radiocommunication Regulations only _permit_ amateur stations
to 'use a code or cipher that is not secret'. That prohibits any form of
encryption unless you publish all keys involved in the transmission. By my
reading of it, it also seems to prohibit creating a digital signature, since
such a signature could be considered a code that is based on a key that is not
public (otherwise anyone could forge your signature). I'm not sure if there's
any official rulings on this.

------
Cieplak
Also, [https://www.tapr.org/pdf/DCC2009-RadioTextMessaging-
WB4APR.p...](https://www.tapr.org/pdf/DCC2009-RadioTextMessaging-WB4APR.pdf)

------
nkeets
If you are an iPhone user, there is a great app called PocketPacket:
[http://itunes.apple.com/us/app/pocketpacket/id336500866?mt=8](http://itunes.apple.com/us/app/pocketpacket/id336500866?mt=8)

------
madengr
Funny that people think Twitter is hot stuff, when APRS was instant, group-
wise messaging, wirelessly, for many year prior.

~~~
01Michael10
What is the percentage of the population who can access APRS at this moment?
1%? Anyone who has a smartphone or a PC can access Twitter which is almost
like 99% of people (in US) these days. Twitter can reach everyone on the
Internet worldwide and APRS not so much...

APRS is a system that has good uses but the Internet is revolutionary.

~~~
XorNot
If we had smartphones with HF radio capability (or someone figured out how to
reprogram the baseband to support it) then we'd be talking.

EDIT: Though I suspect this isn't really practical. Are there any amateur
bands near the GSM/CDMA bands?

~~~
dunmalg
GSM-450 is pretty much right there at the top end of the 70cm, and GSM-950 is
right in the middle of 33cm, but here in the US at least the FCC is pretty
nuts about insisting that stuff sold here is locked out of other devices'
yards. They'd flip out if you tried to import an HT that could hit GSM freqs.

~~~
tlrobinson
> They'd flip out if you tried to import an HT that could hit GSM freqs.

How did Chris Paget's IMSI catcher demo at Defcon a few years ago work then?
[http://blog.marinetelecom.net/2010/08/01/ham-radio-
operator-...](http://blog.marinetelecom.net/2010/08/01/ham-radio-operator-
chris-paget-kj6gcg-spoofs-as-900mhz-gsm-tower-and-15-phones-in-defcon-hacker-
convention-log-onto-his-network/)

~~~
dunmalg
>How did Chris Paget's IMSI catcher demo at Defcon a few years ago work then?

Oh, it's actually not too difficult to modify transceivers to work outside
their regional prescribed bands. There are usually internal jumpers or, more
recently, firmware modifications to expand their tuning ranges to include
bands normally only allowed in other regions. Some of the software defined
radios are surprisingly malleable. I was actually mostly just thinking about
the possibility of getting a GSM phone to hit an amateur band freq or vice-
versa without a lot of hacking.

------
drdaeman
That's xkcd#927, as I get it?

~~~
abruzzi
Not exactly. This isn't about creating a single protocol to replace the
existing protocol, but instead recognizing that there are many existing
protocols in use today, none of which seems likely to supplant all the others,
and instead looking at ways to tie the systems together so I could send a
message from my APRS radio to someone else using D-STAR. The bridges would
happen behind the internet gateways to the systems so the RF side doesn't
change, and no one needs to upgrade hardware.

