I would be concerned about unintentionally running afoul of FCC regulations since encryption is not allowed on US amateur frequencies, that means using something like SSH or loading an SSL webpage with this modem would be a violation. I would also be very concerned with the OS background processes that may use encryption by default.
At international level, encryption in ham bands is forbidden (at least).
The legal definition prohibiting encryption is in §97.113(4) and says that "messages encoded for the purpose of obscuring their meaning" are prohibited. This is generally accepted to be a blanket prohibition of "encryption" in the sense that SSH, SSL, TLS, VPN type traffic would be prohibited.
However, there are some interesting and positive nuances because the rule specifically doesn't ban "crypto". For instance, it is my belief that cryptography for the purpose of authentication or message signing/integrity checking is completely permissable. That is to say that you can even technologically allow things like TLS and HTTPS so long as you force a NULL cipher; so you get message integrity but no encryption so some observer could see all the traffic but not be able to interfere.
Now that we live in a world where my writing this message to you (and, in fact, to the world, publicly under my name) goes over an encrypted channel and it would be unthinkable if it didn't, and where my texts to my friends about where to get dinner happen over an end-to-end secure messenger, and where most competent cryptography is developed in public, it's not clear the rules make sense any more. But that's where they come from.
BTW, one ham has argued that encryption for the purpose of using a standard protocol like WPA/802.1x (or, probably, SSH or SSL) that is otherwise compliant with the intent of the amateur service is legal, because the purpose of the encryption is not obscuring their meaning, the obscured meaning just a side effect of other goals: http://www.n5dux.com/ham/files/pdf/Data%20Encryption%20is%20...
Encryption is illegal as you stated. However "Unique encodings of an analog or digital nature" are completely legal. You don't even need to tell the protocol.
We had this issue with D.star where it was an amateur radio digital protocol in which they didn't tell how to encode or decode. Brought up at an FCC hearing and deemed completely legal.
So call all encryption a "Unique encoding" and you're legally in the clear.
This can't be right. IIRC you have to publish in a public place how your code works, and I believe the D-STAR specs are public; its just that any implementation is blocked because of copyright or whatever dumb crap.
Authentication without encryption isn't very useful, unless you sign every message.
specifically §97.309 (4) (b)
It looks like 433 MHz is unlicensed in Europe so IoT devices can use it at low power. In the US 900 MHz is used instead.
Can I speak a language only known by me and one other person over HAM radio?
If you happen to speak a language that's not commonly known in the area then that would likely be fine.
In short, if the traffic is encrypted, how would we know that, say, Verizon isn't off-loading traffic to amateur bands?
I want to see it adapted for the lower frequency ISM bands. I just got into ham and SDR this last year and I'm looking forward to making a super long distance super low speed link to my buddies on the other coast as a backup comm channel in case the primaries go down.
Many things have been prototyped in terms of communication modes. Just a few examples WSTJ, FT8, PSK31, MSK are all developed by hams for hams.
And there is along and continuing tradition of building your own radio.
Provided you stay within the limits of your license you are welcome to experiment all you like.
Additionally, if you want to exceed the normal limits of your license then you can apply for an experimental license.
Is there also a ban on encryption in the countries where it exists, or is that an FCC-only thing?
I'm interested in this stuff because I just started playing with these: https://cdn.sparkfun.com/assets/a/a/0/b/5/DS_SX1276-7-8-9_W_...
They do spread spectrum on ISM bands with extremely low data rates for insane sensitivity. I want to see what kind of stable distance you can get with lower frequencies and possibly even lower bitrates.
What do you mean? This is running on 433MHz, which is within the 70cm amateur band (420-450mhz)
I haven’t researched the global commonalities, but I’d wager there’s more consistency in HF than the higher frequencies (VHF, UHF).
Interesting, can you provide any more information? How could you do radio that far? Googling shows it is at least 2,092 miles. What kind of radio can go that far?
Also, I'll add a link to http://wsprnet.org/drupal/wsprnet/map . Essentially this shows the transmitter and receiver locations for low power beacons, which might give you a sense of what HF propogation looks like. It will vary according to the time of day and solar conditions.
And I wouldn't. Not trying to be an arse here... but more importantly, who cares? Someone has to discover whats happening and actually care that a rule is being violated. There really are not many hams that have the skill to figure out what is happening when they hear this on their precious 70cm band and THEN realize encryption is happening on top of the network layer. Sure, they exist, but they are also generally busy doing real things that matter rather than volunteering for the Amateur Auxiliary.
Queue: the relentless flood of pitch forks that "CRYPTION IS AGAINST THE RULE OF LAW ON MY HAM BANDS".
But to answer your question "who cares?", hams care, and I'd be surprised if people sending encrypted transmissions are not soon discovered - and if you knowingly violate the regulations, you run the risk of losing your ham license. If you're not licensed, (or even if you are for egregious or repeat violators), there are various enforcement actions the FCC can take including significant fines, equipment confiscation, and other criminal penalties.
In my experience, there absolutely are plenty of hams out there who will triangulate you and report you for violations. You'd probably get away with a warning at first, to be fair, but many hams (at least around these parts) are old retired dudes with nothing better to do.
If you think I'm wrong, just walk around any ham fest and ask for help setting up your Winlink node ;-).
That being said these bands are out there for the public to use, the government has set aside a pretty decent portion of the available usable frequencies for use of the public. In my opinion is just in poor taste to not follow the rules here.
In these days when you can get a Baofeng HT for $25, there are already all sorts of unlicensed people stomping all over others just to be jerks.
The NPR protocol is designed to transfer IP data over radio links, in a bidirectional way (single frequency).
This protocol is in the middle between old packet radio (AX.25) and HSMM-Hamnet with Wifi equipment.
This protocol is designed by a HAM for HAMs. The project is 100% open source : specification, software, PCB.
This solution is complementary to HSMM-Hamnet (which uses Wifi equipments), on lower frequencies 70cm). Radio links on 70cm band is much more robust to obstacles.
The data-rate available is also much smaller, but yet useable. We can achieve several hundreds of kbps. The protocol is designed for “point to multipoint” topology, with 1 central relay (called Master) and several clients around.
We need the ARRL to stop wasting their time on a watered down HOA bill that they've been working on for like a decade, and start talking to the FCC about modernizing regulations for the 21st century. Two things that come to mind are that the spread spectrum/transmit bandwith restrictions are outdated, and encryption requirements need to be formally relaxed so that common digital communication like SSH or HTTPS can be supported to an extent -- I'm not saying I want the ham bands filled with encrypted traffic, but I'm fine with the small community of packet radio enthusiasts being able to remote into a computer from afar.
These ISM modules will work on low power for close range links, but you can't just slap an amplifier and call it a day. There are regulatory issues with the tech they use (spread spectrum, wide bandwidth, encryption, etc).
I would have thought that HAM operators need to fight to keep the regulations that they have, and that trying to make big changes would lead to worse outcomes?
I had an idea for something like this a few years back, would love to experiment!
Any idea where this falls in terms of broadcast regulations? From what I can recall in the US, data must be in the clear and not encrypted on ham frequencies, although I am not a licensed ham so can't say for sure.
Additionally, no commerce is allowed, so connecting this to the actual internet would be fraught with risk.
Communications in which the operator has a pecuniary interest are prohibited. But, personal communication with a business is allowed. Ordering a pizza via phone patch is allowed but soliciting orders for your pizza shop is not.
There are other issues that would make connecting to the internet problematic that are prohibited by §97.113. Things like cryptography, obscene or indecent words or language; false or deceptive messages ...
1. https://www.law.cornell.edu/cfr/text/47/97.113 §97.113(A)(3)
Edit: I found this article on authentication that supposedly is fine, but I'm not licensed so I don't know how valid it is. https://rietta.com/blog/2009/08/17/authentication-without-en...
You are not allowed to encrypt data on ham bands (this seems to happen Worldwide, it is also true here in Brazil), but there is no restriction on use of cryptographic primitives for authentication. But some countries (France, AFAIK) also require the protocol specs to be openly available, what should not be a problem in this field.
Digital signatures are Ok as long as the content of the message is not hidden (i.e. all listeners can receive and decode the information) and the transmission is identified (as usual in ham).
In the general case, there is nothing illegal about sending a PGP-signed email over Winlink, for example. But the message itself must be in the clear. It's just about the fear of foreign spies obfuscating their messages and Red Scare fearmongering.
Of course, in a world with Tor and $30 TracFones with unlimited data, this concern is totally ridiculous. But it is what it is, for now.
I kid, I understand the reasoning but I wish there was some longer-range frequency band with similar restrictions to 2.4GHz
There's a lot to overcome (having everything be completely decentralized), but a person can dream...
Perhaps in the next 50 years people will have their own personal satellites in orbit and we will achieve your goal.
So it's getting cheaper for sure! While that's certainly not the cheapest, it's now within reach of small startups/passionate makers which is exciting!
I love that comment sections are inevitably choked up with people say can't or won't since it's easy to say no.
That said I do hate my ISP (and most others) with a burning passion so...
It has both a Lora mode and raw radio mode, I've been utilizing the raw radio mode.
I'm going to use Java, the tricky parts will be to build the frequency hopping (for me 410-525MHz) + power lowering (-1-+14/+20dBm) parts so that densely populated areas can function properly.
I'm curious on your choice of optimization algorithm to balance cell size/interference with relay congestion.
This is HN, can we be above personal attacks please? You don't know me.
What is the range of HSMM/Hamnet ?
Can you have a "Hamnet BBS" and if so, do you need a separate radio for each "line" ? Or can the BBS have a single radio that shares incoming connections on different sub-frequencies of (whatever band you're using) ?
Page 14, the guide explains the connection to the modem is possible with Telnet with no password...
That's a common issue in IoT and embedded systems, it seems, so I'm wondering if there is a reason why hardware developers just fail at security ?
So yea on authenticity and access control, nay on transmitting ciphertext.
My only comments from reading the protocol spec -- and I need to emphasize, this is one British ham's opinion and is worth precisely what you paid for it, i.e. nowt :)
- Data whitening is a great addition. Too few ham protocols use this, and as a result it's a pain to find suitable transceivers (other than ham-spec ones) for them on the used market.
- Forward error correction scheme looks a bit weak. Nice compared to most ham protocols though (which sometimes just have a CRC).
The main thing is, if you get a burst error which straddles two blocks, you lose block N's CRC and block N+1's first few data bytes -- which would be uncorrectable.
- It'd be nice to see some narrowband modes, maybe 8Kbps in a 12k5 narrow channel or 16Kbps in a 25kHz channel. With 45kHz deviation 360kbps 4GMSK (Mode 22), you're looking at 270kHz bandwidth. That's pretty darn wide! So wide, in fact, it wouldn't be reasonably usable in the UK if you wanted to adhere to the RSGB Bandplan.
I think it should be possible to get some pretty big improvements in error correction by using a better error-correction code (POCSAG's (31,21)BCH code would be a good starting point) and employing bitwise interleaving.
The idea is -- you'd add the error correction first, then interleave the bits. This means that when you deinterleave things at the other end, any burst errors will become single-bit errors in multiple codewords. Single-bit errors are much easier to fix than bursts!
8:1 interleaving with POCSAG's error-correction scheme would give a 21-byte packet size inside a 32-byte transmitted block (giving ~67% efficiency or ~33% overhead). It'd be able to correct up to a 16-bit error burst thanks to (31,21)BCH's ability to correct 2 erroneous bits. This is, actually the same method used by the FLEX-TD paging protocol (documented in ARIB standard RCR STD-43) :)
73's, de M0OFX :)
EDIT: Forgot to show my working, oops! The GFSK occupied bandwidth formula I used was from here: https://www.silabs.com/community/wireless/proprietary/knowle... (bear in mind GMSK is GFSK with the requirement that the modulation be phase-synchronous, i.e. data changes only occur when the IF/RF is at zero phase)
I just calculated the OBW of Mode 24 (4GMSK 500ksym/sec). 750kHz! That'd be 30 of the 25kHz Digital Comms channels... yikes. I'd expect complaints from local hams about the QRM.