Off Grid Digital COMMS Discussion

For quite sometime I have had a deep a personal desire to find a usable communication method to Send and Receive SMS/Data messages without relying solely on the current Paid/Regulated service providers. I believe this is extremely useful in the event of a serious regional emergency that possibly disrupts the current cellular infrastructure.

Today during another forum discussion the topic of "Off Grid Digital Communications came up in relation to ISP's potentially blocking network traffic of websites, organizations or persons deemed to be participating in any form of speech deemed to be inappropriate. Ironically after careful consideration, it seems that this latter scenario may actually be more likely than disruption via natural disaster. I'm reminded that 1.4 billion people in China have their communications effectively controlled by probably less than 10,000 government bureaucrats. While we here in the U.S. are not subject to such restrictions overt, it seems that small groups of individuals working within organizations can have significant unchecked influence in determining who's communications should be restricted or blocked.

My limited research has uncovered that I'm not the only one who is seeking such a technology and there seem to be some experimental and commercial headway in finding viable solutions to the problem along with quite a few DIY and Opensource attempts. Unfortunately many of these open source projects incorporate technical skills that I do not yet have. So, one goal of this post is attract the attention of those with technical expertise to help explain some of these more complex topics and/or even help create a solution.

I would like this discussion to be limited solely to technology and feasibility of possible solutions.

What Features/Capabilities would this hypothetical communication have?

Here is my stretch list, knowing in advance that it's probably not possible for a device to have all of these features. At least it's can be a point of discussion.

1. Low Cost readily available components. Target less than $50 per device.
2. Low power similar to current handheld HT's or Cell Phones
3. Small Size, similar to cell phone/Pager
4. Data only. Most likely SMS/Text but could include GPS location data.
5. Open Source software/hardware
6. Reasonably long range 5km but 25km would probably be ideal.
7. Easy to use, must be totally usable by untrained persons, Wife, Little Kids, elderly parents, ect.
8. Can be operated totally legally with respect to FCC Rules. Perhaps falling under FRS/GPRS or MURS licensing if that were even possible.
9. Secure/Encrypted transmission.

I'm going to post the products or projects that I've already found in a follow up post and leave some space on in this post for any real highlights that come about from the discussion.

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Existing Off the shelf products that I've discovered which meet some of my device goals. If anyone knows of any others, please post them here. While they may not do everything I want, they still could provide insight into how to solve the problems.


GoTenna
This is a wireless radio device that uses the MURS frequencies. They are small enough to fit in your pocket, they batteries last at least 24hrs, they have built in GPS and allow the user to send and receive SMS messages using a Bluetooth connection to your phone. They have a range of about 1-2 miles by themselves. However they also operate in a passive mesh mode. So if you were in an area with say dozens or perhaps hundreds of persons all equipped with GoTenna's you could potentially transmit messages much further. I have read about people who have hacked these devices to add larger antennas, attached them to solar panels and mounted them on tall buildings or towers to create a larger functioning network range with fewer mesh users in the area. I also read about someone who attached a hacked device to a kite and created a temporary repeater at an elevation of about 500ft this increasing the usable range quite a bit.

Here is how it matches up to the goals.

1. Cost - $180/Pair plus $10/Month for live Topo map overlays for the phone app, but this is not required.
2. Power - 24hr battery life but can be recharged with standard MicroUSB cable.
3. Size - Very small, slightly larger than a car keyfob
4. Data - Send and Receive SMS Messages, Emergency Messages and GPS Data
5. Open Source - NO
6. Range - 1 watt of transmission power, 1-2km direct communication but can be extended in a mesh network.
7. Ease of Use - Extremely Easy - App is pretty self explanatory.
8. License - No User License Required - MURS Frequencies
9. Secure - Yes communications are encrypted

Pros/Cons
For the most part this device does just about everything I was looking for however the range is pretty limited. Without a large number of users in the area there is really no way to extend range either, which limits it's usability to backup communications in say a crowded place like a concert or demonstration.

Additional Links:
Amazon Link
Wikipedia Link
GoTenna Review Video


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PowerTALKIE
I saw a discussion of this product on the Radio Reference forums last year and it seemed intriguing. It looks like a familiar Ham HT but it's not actually how they work. Basically this is a HT that transmits Data on GMRS frequencies which is FCC Part 95 legal. Their range would be similar to a standard GMRS Handheld, but what I don't know is if you can transmit data through Repeaters. If so you could substantially increase their functional range. If anyone has any experience with these, I would be interested in knowing more.

Here is how it matches up to the goals.

1. Cost - $55/Pair
2. Power - Supposedly has a 6000mAh battery, claims 6 days of continuous use! It can be recharged with standard MicroUSB cable.
3. Size - Handheld HT Radio size
4. Data - Send and Receive SMS Messages, Emergency Messages and GPS Data using Bluetooth Mobile Phone APP.
5. Open Source - NO
6. Range - 2 watt of transmission power, 1-2km direct communication (May be able to access GMRS Repeaters, and range could be extended with better antenna)
7. Ease of Use - Seems like the app is pretty easy to use
8. License - GMRS Family License is Required
9. Secure - Unknown

Pros/Cons
This is a ChiCom product. Discussion on RadioReference.com notes that the removable antenna actually violates FCC rules for devices transmitting data. So it's possible these devices could loose certification at sometime in the future. However their low cost seems to be a big plus and it may be worthwhile for me to pickup a pair of these and test them out.

Additional Links:
Amazon Link
Radio Reference Discussion
PowerTALKIE Review Video

Satellite Messaging devices exist and operate on the Iridium satellite network. The devices themselves are all fairly expensive ranging from $250-$500 and they all require a monthly service fee, not to mention they still are controlled by a for-profit entity. However their biggest advantage is the fact that you really have worldwide coverage provided you are in direct line of site to a satellite. Pretty much means that you need to be outside to communicate.

Here is a quick list of a few that I had discovered.
Spot-X $299 + Monthly fee $12/Month is the least expensive option but more than adequate for emergency Communications.
Garmin In-Reach $350 + Monthly fee $12/Month
Garmin GPSMAP 66i Same as the Mini but includes GPS Topo map support.
Zoleo $199 + $20/Month - Similar to Garmin In-Reach Mini

These are tempting to consider. I'm sure if I found myself in a serious emergency I would wish that I had one. However if I wanted to outfit my entire family with Spot-X's for example, I would be spending $1300 out of pocket plus $48/Month for the service. That's just way too much to spend at this time.

I'll add any others that I find.

Will ham packet radio serve your needs? It was quite popular with the DXers in the pre-internet days. There was a 2 meter packet network up and down the east coast that I would connect to whenever I was on the radio chasing DX.

LoRa and LoRaWAN

This is a copy of my previous post in the Parler thread.

I discovered LoRa and LoRaWan sometime last year, but the Arduino programming was a bit over my head to really pursue. I was intrigued that a small battery powered device could transmit at such long distances. This is a typical LoRa module https://www.amazon.com/dp/B07916Q3T6/


Here is a good video demonstrating building small, and very cheap, LoRaWan devices to create a personal mesh network capable of sending direct SMS messages without relying on any ISP.

https://youtu.be/TY6m6fS8bxU

Here is a link where I guy builds LoRa devices for direct communication without a mesh network.

https://youtu.be/b_RPwtxtNdc


Recently I’ve decided that it’s worth investigating further and I decided to start teaching myself Arduino basics to build some of these devices for testing. I got a simple Arduino starter kit and an accompanying book.



This is still a bit over my head and I've got a lot to learn about LoRa and Arduino but from what I can tell so far LoRa devices work very much like the GoTenna system. However they potentially have Much Further Range. I think the world record is something like 700+ Km! They also operate in much much lower power. So devices can work for weeks or even months on a single charge. The main difference is that they trade speed of transmission for range.

Here is how I think it stacks up to the goals.

1. Cost - $20-30/ for DIY parts
2. Power - Devices reportedly can operate for weeks or months on a single charge
3. Size - Very Small, smaller than GoTenna
4. Data - Send and Receive SMS Messages, Emergency Messages using bluetooth phone connection (this is still very experimental)
5. Open Source - Yes
6. Range - 100mw power, but the system is designed to transmit very long range. Mesh network capabilities would extend range much further.
7. Ease of Use - No, Not ready for prime time yet...
8. License - None required, operates on assigned 900mhz frequencies in the us.
9. Secure - Yes

Shazam said:

Will ham packet radio serve your needs? It was quite popular with the DXers in the pre-internet days. There was a 2 meter packet network up and down the east coast that I would connect to whenever I was on the radio chasing DX.

Click to expand...

I'm familiar with packet radio and i've used FlDigi through my base station. In my specific use case it's totally impractical as a mobile device that can be used in place of a cell phone to send SMS messages in an emergency situation. However I still think that packet radio options do belong in this discussion.

Here is a link to an open source project called AirChat which uses FlDigi to send sms messages including encrypted messages which are illegal on ham bands in the U.S.

https://github.com/lulzlabs/AirChat/blob/master/README.md

ToolAA said:

I'm familiar with packet radio and i've used FlDigi through my base station. In my specific use case it's totally impractical as a mobile device that can be used in place of a cell phone to send SMS messages in an emergency situation. However I still think that packet radio options do belong in this discussion.

Here is a link to an open source project called AirChat which uses FlDigi to send sms messages including encrypted messages which are illegal on ham bands in the U.S.

https://github.com/lulzlabs/AirChat/blob/master/README.md

Click to expand...

Look at amateur radio mesh networks, think of it as 801.n wifi but on steroids. There is already a network to play with here in Maryland.

ToolAA said:

I'm familiar with packet radio and i've used FlDigi through my base station. In my specific use case it's totally impractical as a mobile device that can be used in place of a cell phone to send SMS messages in an emergency situation. However I still think that packet radio options do belong in this discussion.

Here is a link to an open source project called AirChat which uses FlDigi to send sms messages including encrypted messages which are illegal on ham bands in the U.S.

https://github.com/lulzlabs/AirChat/blob/master/README.md

Click to expand...

If all you want to do is SMS, APRS already supports that, and has since inception.

I’ll be following this closely. Just picked up an FT3DR with moseying APRS thoughts in mind when I’m away from the vehicle with the beefier rig.

dblas said:

If all you want to do is SMS, APRS already supports that, and has since inception.

Click to expand...

There are two reasons why APRS isn’t the best choice for the desired application. It still relies on the internet to relay messages and it requires an Amateur License.

I’ve used APRS to send messages to a mobile phone but that feature is not natively supported either. The messages are technically sent to an internet connected gateway SMSGTE. That specific gateway is possibly the most vulnerable link in the emergency Communication chain.

There are still good reasons to discuss APRS here. For example would it be possible to create your own gateway if necessary?

I'm going to come back and read some of the stuff up above about GoTenna.

I'm going to research it as a possibility for my inner circle of friends and family.

Setting aside the Leftist Digital Night of the Long Knives (LDNOLK), those of us that have lived through some of the other things that have affected communications might also be interested in it.

GREAT THREAD. CRITICAL TOPIC.

I just encourage you to consider that at some point, transmission invites attention. Not right away certainly.

Also, jamming is real and will be high on their list if WE derive much utility from any of the above.

Alea Jacta Est said:

GEEAT THREAD. CRITICAL TOPIC.

I just encourage you to consider that at some point, transmission invites attention. Not right away certainly.

Also, jamming is real and will be high on their list if WE derive much utility from any of the above.

Click to expand...

Reading I've done in one place elsewhere says that with these mesh networks, the power is so low that if they cast a big enough jamming signal to cover a broad geographic area, it screws with official stuff too.

Still need to read more about that.

Also, if it gets to that point where they are seeking out to jam citizens' individual communications, we have a bigger civil liberty issue than anyone could have ever imagined. I've already seen the ACLU have an "oh shit moment" on the DNOTLK this week.

Yes sir. The complexity of the threat and potential for problems within our many alternative solution sets is yuge.

I’m tickled that folks are thinking this way. And more tickled they’re taking constructive action.

Somebody posted in jest about carrier pigeons... IMO, that shouldn’t be funny but actionable.

subscribed, thanks all, I have several family households that I would prefer to be in touch with, needs to be easy as most do not like to delve into tech. Special Shout Out to Tool!

FWIW: On grid communications can be made fairly secure with GPG/PGP ( https://gnupg.org/ ). The 4096 bit key is pretty secure and will keep most folks out of your business. Using encrypted messaging on the Internet may raise eyebrows though.

Encryption is the norm in many college/educational email accounts ( .edu ). Less chance of being singled out on encryption here. You can get an account at many colleges by just requesting an application to the school, although you may have to pay a fee.

Norton said:

I'm going to come back and read some of the stuff up above about GoTenna.

I'm going to research it as a possibility for my inner circle of friends and family.

Setting aside the Leftist Digital Night of the Long Knives (LDNOLK), those of us that have lived through some of the other things that have affected communications might also be interested in it.

Click to expand...

I have a few GoTenna’s to augment my off grid comms approach that also includes Iridium (Garmin InReach), and analog radios (VHF).

GoTenna is a cool product, but the main issue is the vendor seems to almost have abandoned their consumer product and is only developing their GoTenna Pro product designed for operators. The other issue is there is no dedicated relay product available, so range is pretty limited in the 900 ISM band they use without a strong mesh. On the plus side they are cheap. If you are surrounded by a bunch of like minded neighbors, you could stand up a network for marginal expense.

ToolAA said:

There are two reasons why APRS isn’t the best choice for the desired application. It still relies on the internet to relay messages and it requires an Amateur License.

I’ve used APRS to send messages to a mobile phone but that feature is not natively supported either. The messages are technically sent to an internet connected gateway SMSGTE. That specific gateway is possibly the most vulnerable link in the emergency Communication chain.

There are still good reasons to discuss APRS here. For example would it be possible to create your own gateway if necessary?

Click to expand...

I am referring to radio to radio, and NO, you do not need to a license to run APRS on other services. Since SMS/data type services are permitted on MURS and GMRS, so to is APRS and the messager part of the service. The best part is an actual repeater (Two radios, two frequencies) isn't needed, as a simple digipeater in an ammo can will suffice, set up a radio running APRS and program as a digi at everyone's house, put up a decent, unobtrusive antenna and have an APRS network, sans internet.

swamplynx said:

I have a few GoTenna’s to augment my off grid comms approach that also includes Iridium (Garmin InReach), and analog radios (VHF).

GoTenna is a cool product, but the main issue is the vendor seems to almost have abandoned their consumer product and is only developing their GoTenna Pro product designed for operators. The other issue is there is no dedicated relay product available, so range is pretty limited in the 900 ISM band they use without a strong mesh. On the plus side they are cheap. If you are surrounded by a bunch of like minded neighbors, you could stand up a network for marginal expense.

Click to expand...

Any idea what the effective range is of a single transmission with no hops? I only need a few blocks, say maybe .5-.75 miles.