SuperPacket

New web page - A Brief Survey of Technological Innovation in Amateur Radio

This is a paper I wrote for the ARRL and TAPR Digital Communications Conference 2022.

A Brief Survey of Technological Innovation in Amateur Radio

By Steve Stroh N8GNJ¹
ARRL and TAPR 2022 Digital Communications Conference Charlotte, North Carolina, USA 2022-09-16 thru 18

Abstract

In recent decades, the perception of Amateur Radio within the general public has shifted from Amateur Radio being useful, innovative, and an interesting technical activity, to Amateur Radio being perceived as an anachronism and largely irrelevant (except in the direst of communications emergencies). Summarized: “Ham Radio – that’s still around?”

Amateur Radio’s service to the public for emergency communications is being supplanted by improved commercial and government communications capabilities such as improved Iridium² satellite phones, the FirstNET³ public safety cellular system, and most recently, the nomadic capability of the Starlink⁴ broadband satellite system.

Amateur Radio has continuously developed unique technological innovations in radio technology, and that has not only continued in the modern era but has accelerated. However, that ongoing, unique contribution to technological society is, increasingly, unrecognized. That is unfortunate. If regulators, lawmakers, industry, the general public... and the Amateur Radio community itself understood the unique contributions to technological innovations in radio technology that Amateur Radio continues to develop, perhaps such recognition might improve Amateur Radio’s perception that it remains a valuable part of society, worthy of continued access to portions of the electromagnetic spectrum.

Keywords

Amateur, Radio, Operator, Ham, Wireless, Technology, Innovation, Spectrum, Digital, VHF, UHF, SHF, Microwave, Communications, ARDC, Techies, Makers, Hackers, Zero Retries Newsletter, Experimentation, Research and Development, FlexRadio, Steve Stroh N8GNJ

Background

For decades, I have been an admirer of technological innovation in Amateur Radio. Not just new technologies like Packet Radio emerging in the 1980s, but new techniques for old problems such as digital techniques enabling reliable communications via unreliable mediums such as the High Frequency (HF)⁵ (aka Shortwave) portions of the electromagnetic spectrum.

Amateur Radio’s unique culture, the varying characteristics of various portions of spectrum allocated to (or shared with) Amateur Radio operations, and the many highly capable and skilled Amateur Radio Operators, have resulted in a fertile, and welcoming “experimental zone” for technological innovation in radio technologies. Until recent decades, that culture of technological innovation was widely recognized, and encouraged. In the last few decades, the recognition of

1 Email – [email protected]
2 https://www.iridium.com/network/
3 https://firstnet.gov/network
4 https://www.starlink.com/rv
5 https://en.wikipedia.org/wiki/High_frequency

A Brief Survey of Technological Innovation in Amateur Radio

Amateur Radio’s utility and contributions to technological innovation have been deprecated to near irrelevence... at least in popular perception... by ubiquitous Internet access, mobile phones, caricatures of Amateur Radio as “Grandpa sitting in the basement tapping on a Morse Code key”, and most notably, the removal of old barriers to individuals communicating across international borders.

A primary reason that this is a concern for society is that it has become irrevocably dependent on radio technology as the primary method of communications for mobile devices, most notably cellular technology, wireless local area networks (Wi-Fi), and most recently, direct-to-user satellite communications. For many people, their mobile phone is their only method of communications and media consumption. Much of that technology has been developed and manufactured in China. Dependence on China for such a critical infrastructure function is proving to be fraught with peril. To counter that peril, the US and other Western nations must quickly develop additional expertise, and personnel, “in nation” to better develop and support this now-critical wireless infrastructure. Amateur Radio can be a “training ground” for developing familiarity and expertise with radio technology, leading to careers in developing and supporting radio technology... but only if Amateur Radio is recognized as a useful and interesting.

The rise of technology specialists, especially those trained in Information Technology (IT), the “Maker culture”⁶, and the “Hacking Culture”⁷ have breathed new life into Amateur Radio. “Techies” have discovered Amateur Radio as an enabling technology for supporting experimentation with Information Technologies (such as building hobbyist / not-for-profit wide- area microwave networks). Makers have discovered that there are incredibly interesting things that they can add to their personal knowledge base and practical projects based on capabilities Amateur Radio has long taken for granted, such as long-range communications via VHF / UHF repeaters. Hackers have discovered Amateur Radio as a fertile “playground” for their experiments and expansion of knowledge about radio technology, such as Software Defined Receivers... and Transmitters (with an Amateur Radio license).

I started the Zero Retries Newsletter⁸ in July, 2021 out of frustration that the totality of technological innovation in Amateur Radio wasn’t being recognized by the Amateur Radio community, its regulators, and especially the public at large. Specifically, I was worried about the growing public perception that Amateur Radio is irrelevant, or worse, an anachronism. Such a perception, if it is to continue for much longer, may prove catastrophic to Amateur Radio, most notably in the loss of Amateur Radio access to various portions of spectrum. To date I’ve published more than fifty weekly issues of Zero Retries, and each issue highlights some aspect of technological innovation in Amateur Radio.

Literally, Amateur Radio is a license to experiment with radio technology and a welcoming “innovation zone” to develop new and exciting technological innovations in radio technology. I hope to make that point with the vignettes in this paper.

 

6 https://en.wikipedia.org/wiki/Maker_culture
7 https://en.wikipedia.org/wiki/Hacker_culture
8 https://zeroretries.substack.com (will eventually migrate to https://zeroretries.org)

...

Read the rest of the paper at:

https://www.superpacket.org/n8gnj_dcc_2022_final_for_web.pdf

 

July 2021 QST Had Some Interesting Technical Content

Image courtesy of ARRL

I was pleasantly surprised by the July, 2021 issue (Volume 105, Issue 7) of ARRL's magazine QST. It was a welcome change to see some content with some technical relevance (circa 2021), such as:

• Page 9 - Second Century - EmComm: It's In Our Purpose by ARRL CEO David Minster NA2AA. I don't agree with him about the relevance of Amateur Radio for Emergency Communications in the 2020s and beyond (basically, we're not). However, it's interesting to see the ARRL's perspective on the tenets of US Amateur Radio in the CEO's own words.
• Page 21, 26, 27 - FlexRadio full page ads. I'm a fan of FlexRadio because they're the only "all in on Software Defined Radio technology" manufacturer in the Amateur Radio industry (in the same way that Tesla is all in on battery electric vehicles). I particularly like FlexRadio's approach to linking their various units - Ethernet.
• Page 38-42 - Review - Icom IC-R30 Portable Communications Receiver Mark Wilson K1RO. K1RO did a nice review, and I learned several things about the IC-R30, such as:
  • The IC-R30 has a Li-Ion battery pack which can be charged the USB connector,
  • The IC-R30 antenna connector is SMA (easily adapted to external antennas),
  • The IC-R30 can be programmed (like a scanner or portable transceiver), either with a .csv file, or Icom's IOS or Android app,
  • The IC-R30 has an onboard GPS receiver
  • The IC-R30 has a microSD card that can store frequency memories and received audio files,
  • The IC-R30 can be controlled via the IOS or Android App via Bluetooth
  • The IC-R30's audio output can be routed to a Bluetooth audio device
  • The IC-R30's list price is $600.
• Page 47-49 - Review - Garmin inReach Mini Satellite Communications Device by Bruce Prior N7RR (yay - a fellow Pacific Northwester). Some of the things I learened about the InReach from this review:
  • It's tiny - 3.9" x 2.04" x 1.03" and 3.5 ounces!
  • It uses the Iridium Low Earth Orbit satellite system (thus works anywhere you have a view of the sky),
  • Has a built-in GPS, and position data is included in any messages sent from the InReach
  • The InReach can be used standalone or paired with a smartphone via Bluetooth,
  • Canned messages can be pre-defined for easy recall and transmission,
  • The price of the InReach is $350, plus varying expense for subscription packages (required, not optional).
  • No, there's no Amateur Radio overlap with this device, other than N7RR includes it with his lightweight Amateur Radio equipment that he takes on hikes.
• Page 54-55 -  Microwavelengths - Understanding Feed Horns for Parabolic Dishes by Paul Wade W1GHZ. He explains the physics of parabolic dishes in an approachable way.
• Page 56 - Eclectic Technology - The Rise of LoRa by Steve Ford WB8IMY. He gives a decent summary of LoRa technology. W8IMY observes "... you're unlikely to be passing voice video data through a LoRa network." At a maximum data rate of 22 - 50 kbps, that's correct, but that's a (potentially) significant improvement over typical packet radio data rates. It's an interesting crossover between license-exempt operation and Amateur Radio operation that's possible with LoRa. In my memory, this is the very first mention of LoRa technology in QST.
• Page 60-61 - AREDN at the US Marine Corps Marathon by Mark Braunstein WA4KFZ. This was the real shocker of QST content. This was a good overview of the tactical (as opposed to infrastructure) use of AREDN systems to support the popular, and large US Marine Corps Marathon in the Washington DC area. Again, in my memory, this is the very first mention of AREDN in QST. 
• Page 103 - A full-page Icom advertisement, but Amateur Radio isn't mentioned. The four Icom radios mentioned are (portable) IC-SAT100 Satellite radio (operates on the Iridium Low Earth Orbit [LEO] satellite network), the IP501H Portable LTE radio, the IP501M Mobile LTE Radio, and the VE-PG4 RoIP (Radio over Internet Protocol) Gateway.

All in all, this issue is definitely a keeper!

Unfortunately, if you're not an ARRL member (most US Amateur Radio Operators aren't members) you'll likely never see these articles unless a friend who is an ARRL member chooses to share them with you (or passes along the entire issue). If you're not an ARRL member, and able to view QST, there's always the entire run of 73 Magazine that's completely accessible online to everyone.

Thanks for reading!
Steve Stroh N8GNJ
Bellingham, Washington, USA
Portions Copyright © 2021 by Steven K. Stroh

 

 

Blast from the Past - Linux Routers and Amateur Radio Spread Spectrum

In doing some research for another article here on SuperPacket, I ran across a prescient statement I made to Linux Gazette (later, Linux Journal?) that routers and gateways used in Amateur radio would be based on Linux. My statement must have made an impression because Linux Gazette posted it on their website.

Subject: TAPR SS Position Statement
Date: Thu, 26 Sep 1996 12:18:44 -0700 (PDT)
From: Steve Stroh
To: Phil Hughes WB6SWR

I suspect that the "Intranet" described below will be built on Linux-based IP routers, possibly a simple implementation that can be booted from floppy or Flash Card.

It's going to be very, very interesting.

Steve N8GNJ, <old email address redacted>
Amateur Radio TCP/IP <old email address redacted>
| Amateur Spread Spectrum is the wave of the present!

...

Fast forward sixteen years... When the Raspberry Pi computers came along in 2012, I knew that they were going to be very popular in Amateur Radio. Finally we had a powerful (enough) inexpensive embeddable computer that ran a powerful operating system that could be "headless" and scriptable and stable. Before then we had embeddable computers that were expensive, Linux was fussy and non-standard on embedded devices, and most Amateur Radio software was running on Windows.

Below is the meat of that email to Linux Gazette.

...

TAPR's Statement on Spread Spectrum Technology Development

http://www.tapr.org/

TAPR was founded in 1982 as a membership supported non-profit amateur radio research and development organization with specific interests in the areas of packet and digital communications. In the tradition of TAPR, the Board of Directors at their Fall 1995 meeting voted that the organization would begin to actively pursue the research and development of amateur radio spread spectrum digital communications. At the Spring 1996 board of directors meeting, the following statement of purpose was passed:

"TAPR believes that the technical facts support our conviction that conventional and spread spectrum systems can coexist without detriment to conventional systems on all frequencies from MF to EHF. To this end, TAPR will begin to research spread spectrum systems that will develop technology for future deployment."
As stated above, the TAPR board feels strongly about TAPR's focus on spread spectrum technology and especially how it relates to the potential coexistence on frequencies that will have increased number of users occupying them. The amateur radio bands, like other spectrum will become more heavily utilized in the future. It is in the interest of amateur radio to develop systems that are interference-resistant while not interfering with other primary or secondary users on those frequencies.
TAPR understands the concerns many have with the new technology, and believes that efforts in both education and research is necessary in order to allay the fears about interference and to demonstrate the benefits of the technology.

TAPR believes that todays' communications technology is moving toward all digital transmitters and receivers. These advances in technology, combined with the swift evolution of cell based transmission and switching protocols, are opening up a new set of possibilities for unique new services utilizing intelligent networks. These will contain smart transmitters, receivers, and switches. Today's Internet is perhaps the best example of a self-regulating structure that embodies these new technological approaches to communications in the networking domain. However, to date, many of these innovations have not moved into the wireless networking arena. TAPR will work on moving these innovations into the amateur radio community.

TAPR feels that the VHF/UHF/SHF radio networks of the future will involve a mixture of links and switches of different ownership, which terminate at the end-user via relatively short-distance links. What will then be required is a built-in, distributed, self-governing set of protocols to cause the network's behavior to make more efficient use of a limited, common shared resource, the radio spectrum. Creating such a self-regulating structure for the optimal sharing of spectrum will require much effort.

One of the major problems which stands in the way of these new approaches today is the current FCC regulatory environment and the manner in which spectrum is managed and allocated under its rules.

Historically, the current regulatory approach to radio has been based upon the technology that was in use at the time that the Communications Act of 1934 was framed, basically what we would call today, 'dumb' transmitters speaking to 'dumb' receivers. The technology of that time required reserved bandwidths to be set aside for each licensed service so that spectrum would be available when needed. Given this regulatory approach, many new applications cannot be accommodated since there is no available unallocated spectrum to 'park' new services. However, given the new set of tools available to the entrepreneur with the advent of digital technology, what once were 'dumb' transmitters and receivers can now be smart devices which are capable of exercising greater judgment in the effective use and sharing of spectrum. The more flexible the tools that we incorporate in these devices, the greater the number of uses that can be accommodated in a fixed, shared spectrum.

Therefore, TAPR will focus its spread spectrum effort in the following areas:

TAPR will work to promote rules and technologies to make the most efficient use of the spectrum through power control, forward error correction, and other means to minimize interference among spread spectrum users and existing communications systems.
TAPR will work on issues and efforts with other national organizations to change the regulatory environment and rules in order to promote the experimentation, development, and later deployment of spread spectrum technology.
TAPR will work to develop information on the topic to help educate members and the amateur community as a whole about spread spectrum technology, and to disseminate this information via printed publications, the World Wide Web, presentations at conferences and meetings, and other means.
TAPR will work to foster experimentation, development, and design of spread spectrum systems, and to facilitate the exchange of information between the researchers and other interested parties.
TAPR will work to develop a national intra-network to foster the deployment of future high-speed spread spectrum systems into regional and local communities, including the development of suitable protocols and guidelines for deployment of these systems.
TAPR will work with commercial companies who manufacture spread spectrum devices which operate in spectrum shared by the amateur radio service (ARS), in order to make them more aware of the nature of ARS operations on those bands with the goal to work towards the deployment of devices which will minimize interference between all spectrum sharing partners.
TAPR will work with commercial companies who manufacture spread spectrum devices in order to identify equipments that can be either used or modified for use for Part 97 operation.
Adopted by the TAPR Board on September 20th, 1996 at Seatac, Washington Board Meeting.

Spread Spectrum Statement Committee:
Greg Jones, WD5IVD
Dewayne Hendricks, WA8DZP
Barry McLarnon, VE3JF
Steve Bible, N7HPR

...

TAPR joined an existing Special Temporary Authority (STA) investigation to operate Spread Spectrum in Amateur Radio spectrum. If memory serves there was a second STA established solely by TAPR. Both STAs concluded with a report to the FCC that Spread Spectrum operations were usable in Amateur Radio spectrum. Years later, the FCC finally made some rule changes regarding Spread Spectrum in Amateur Radio spectrum. The FCC's new rules were overly cautious regarding Spread Spectrum operations by Amateur Radio operators with onerous restrictions on power levels that the American Radio Relay League insisted on to protect legacy modes. In 2021 Spread Spectrum operation in Amateur Radio is "common", but only in the bands that Amateur Radio shares with / adjacent to Part 15.247 devices, namely in the 902-928 MHz, 2.4 GHz, and 5 GHz bands.

I participated in one or both of the STAs. In my report to the FCC, I concluded that Frequency Hopping Spread Spectrum (FHSS), even at high power levels, was completely compatible with Amateur Radio operations in Amateur Radio VHF and UHF bands, due to the minimal "dwell time" on any one portion of an Amateur Radio band. In 2021... due to the very minimal use of repeaters for voice communications, my conviction of the usability of FHSS in Amateur Radio is even stronger.

Amateur Radio dreamed bigger back then. I hope that with some new capabilities, Amateur Radio can dream big again.

Thanks for reading!
Steve Stroh N8GNJ
Bellingham, Washington, USA
2021-05-07

Updated Interesting and Advanced Projects / Products in Amateur Radio page

I made a number of additions to my web page Interesting and Advanced Projects / Products in Amateur Radio.

There is no change log or diff available - it's intended as a cumulative list of Interesting and Advanced Projects / Products in Amateur Radio.

Thanks for reading!

Steve Stroh N8GNJ
Bellingham, Washington, USA
2021-04-20
Copyright © 2021 by Steven K. Stroh

More on Using AREDN

(This was originally published on N8GNJ.org, and copied here; SuperPacket is now my "big picture of Amateur Radio" blog for articles like this - see About SuperPacket.)

Amateur Radio Emergency Digital Network (AREDN) is a firmware image for selected Wi-Fi access points and Wireless Internet Service Provider (WISP) units. AREDN's firmware adds various services such as Domain Name Service (DNS) and Dynamic Configuration Host Protocol (DHCP) and most notably, hands-off mesh networking (sometimes called peer to peer networking). As part of the AREDN firmware, it enables the Wi-Fi radio to use a portion of the 2.4 GHz band that is only legal for use by (licensed) Amateur Radio operators. You don't have to be an Amateur Radio operator to use the firmware, but you do have to be an Amateur Radio operator to make use of the additional channels.

AREDN is useful enough that I think every ham that has a Go Kit with a computer, should have a few AREDN nodes in their go kit. My rationale for making that statement is one of the issues that Amateur Radio operators have in responding to emergencies with their go kits (again, with a computer) is that there is no good, and certainly no easy way to have their computer communicate with other Amateur Radio operators. I've observed many, many times when computer-to-computer communication devolves to putting a file on a USB memory device that's then "sneakerneted" to another computer. AREDN units are a fix for that. AREDN is mostly "plug and play" to use, but some preparation is required.

The easiest way to understand and experiment with the potential of AREDN is the GL-iNet GL-AR150 shown above. It's around $25 on Amazon - buy two for your experimentation. The model in the photos above has an internal antenna. The GL-iNet GL-AR150-ext features an external antenna port and a small antenna. The big brother of the GL-150 is the GL-750, which is a bit more expensive, but has the benefit of a 5 Ghz radio in addition to the 2.4 GHz radio.

The best way, I think, to think of AREDN nodes for this use case is that they're the rough equivalent of an Ethernet switch and Ethernet cables connecting multiple computers together to share resources, such as a local web server, file sharing, or any other service we take for granted via the Internet - as long as it can be hosted locally. Think email via POP/SMTP, but not Gmail.

After it's flashed with the AREDN firmware, there is some minimal configuration required, including entering your callsign and setting up a password. I recommend installing the tunnel software (allows you to create a Virtual Private Network - VPN to other AREDN nodes via an Internet connection). The tunnel software doesn't take up much room and it's much, much easier to do it when you have a good Internet connection rather than adding it later on a marginal or no Internet connection. Unlike the initial firmware installation, the tunnel software must be done "live" - you can't download it for later installation.

(Apologies that I'm describing all of this with words rather than photos - a future version of this will include photos.)

Then it's as simple as providing the AR150 power via USB (it doesn't need much - a computer's USB port is adequate) and plug the AR150's LAN Ethernet port into the computer's Ethernet port. Assuming you select the default radio settings, any other AREDN node within range (with the same radio settings) will automatically connect into a mesh network.

The real power of AREDN is the services beyond the AREDN nodes. In my example above of multiple Amateur Radio operators in a shelter, one computer can be configured as a web server, advertise that server on that particular AREDN node, and then anyone else in the AREDN mesh can click on that advertised service and see the web page.

The use case I'm describing here hasn't been discussed much (that I've seen).

I have a mild criticism of AREDN that they posit its role as outdoor infrastructure, and in my opinion, that's somewhat impractical. 2.4 GHz is hard enough to make work, even with the "quiet" portion of spectrum that AREDN is using. The better model for Amateur Radio high-speed microwave infrastructure, in my opinion, is HamWAN. Alternatively to HamWAN's way of doing things, you can buy off-the-shelf Wireless Internet Service Provider (WISP) equipment designed for this purpose (thus, it's expensive). Vendors of WISP equipment include Cambium Networks, Ubiquiti Networks, and MikroTik. While this is equipment intended for WISPs, because it uses license-exempt spectrum (generally 5 GHz), it can be purchased and used by anyone. One good vendor of such equipment is Streakwave Wireless. It's a bit of work to get them to work with an individual, but they're willing to do so.

I'm now able to access two AREDN Virtual Private Network tunnels, one for my fellow Amateur Radio operators in Whatcom County, and another for my buddies in the Seattle area. One issue to be careful about is routing loops so I'm careful to keep the two networks segmented for now, as I want to experiment on both of them. I have two sets of AREDN nodes in my shop, and they don't interoperate with each other because of of unique radio configurations for each group.

My friend Bill Vodall W7NWP made a good set of notes on configuring the AR150s.

Next steps in experimenting with AREDN:

• Configure a Raspberry Pi as a web server and advertise that service via AREDN
• Configure my new TP-Link 2.4 GHz radio to try to connect with the nearby AREDN node,
• Learn more about advertising services, such as VOIP, email, etc. via AREDN
• Order more AR150s, get them configured into a Go Box configuration with their own battery packs, weatherproof boxes, and better antennas for better range.

Update 2 - 2021-02-23 - Displaying a web page on an AREDN Node, from the AREDN node

The one thing I wished was possible on the AREDN nodes was to display some custom text like a small web page. It would be ideal if this was automated, like a checkbox to display custom text. When I plainted this desire to my long-suffering techie buddy Bill Vodall W7NWP, he was completely puzzled - "Steve... it has a web server already running. You're looking at the status page in a web browser, aren't you?". That was my D'oh moment. So then Bill and I went on an hours-long quest to figure out how to access it. Turns out you can ssh and scp into your AREDN node - IF you know what you're doing.

Part 1 - Make a simple web page

You can't effectively make changes to a file from / on the AREDN node. Well, technically, you can, but you the only editor available on an AREDN node is the vi(le) editor. Life's too short.

So, compose a web page that you want to be resident on your AREDN node on your "big" computer. It needs to be "something".html. Keep it simple. Compose in an HTML editor or a text editor, and keep it to text only (no images). Save it as a simple text file. If you're rusty on your HTML, as I was, here's an HTML intro. 

Save it as n8gnj-test1.html (whatever name makes sense to you). Make sure you can find this file when you're in the command line using SSH. 

Be sure to view your file in a web browser:

http:///path/filename 

Part 2 - SSH

ssh -p 2222 [email protected]

ssh is Secure SHell. -p specifies the port which on an AREDN node is 2222 for ssh and scp. root is the username on the AREDN node, and n8gnj-1 is the system name (technically, it's N8GNJ-1 but the system doesn't seem to mind, and it's easier not to shift to all caps.

Also, the system doesn't seem to care about using n8gnj-1 vs using n8gnj-1.local.mesh, so I used the former.

and you're prompted for the node's password, and you're in!

But that was only part of the battle, but at least I could look at the file system from the inside.

Part 2 - SCP

The beauty of UNIX / Linux is that the tools like SCP have been honed over decades. They work... you just have to know how to use them. The available documentation, especially on a system, like man scp are terse at best. So it took Bill and I hours to get this right. Well, to be fair to Bill, it took him tens of minutes to get it right (based on my feedback) and it took me hours of fiddling around.

scp -P 2222 n8gnj-test1.html [email protected]:/www/n8gnj-test1.html

scp is Secure CoPy. -P (note that for scp, it must be an uppercase P) specifies the port which on an AREDN node is 2222 for ssh and scp. root is the username on the AREDN node, and n8gnj-1 is the host name.

n8gnj-test1 is the file that I created on the "big" computer.

The fiddly bit was the :/www/n8gnj-test1.html. :/www/ specifies that the scp command copies the n8gnj-test1.html file into the /www directory of the AREDN node. (You have to know a valid directory in advance of this command, thus it's useful to know how to use ssh). something2.html is the name of that file when it's copied onto the AREDN node (in the /www directory).

and you're prompted for the node's password, and if everything is correct, scp terminates. Then go back to ssh, and look at the /www directory, and there should be a something2.html file there.

At this point, you've moved a file into the file system of the AREDN node. Then, you get to get to do configuration magic to display it from the main AREDN node status page.

Part 3 - Configuration of a link to display

(Apologies that this next part is terse - I want to capture it before I forget these fiddly bits.)

Go to Setup, Advertise a Service.

• Name Box: (what name you want to appear under the Services column next to your node in the Mesh Status page) I put N8GNJ Simple Web.
• Click the Link checkbox (it will appear as a clickable link)
• First box - HTTP (pulldown, I think)
• Second Box - select your node from the pulldown. In my case it's N8GNJ-1.
• Third box (after the :) 80 (port number, apparently; Port 80 is universal for HTTP).
• Fourth box is the name of the file in /www. In my case it's n8gnj-test1.html. (Apparently the /www is prepended and no need to have it in the string - just the filename.)
• Click the Add button. It'll take a few seconds for it to update.
• Click the Save Changes button (above). It'll take a few seconds to save this new configuration.

Normally, this capability is used to advertise a service on another system; there are dozens of examples. Mine was going to be a web server running on a Raspberry Pi, but what I wanted to display is pretty simple, and it seemed like this should be possible, but there were only the vaguest of hints that this was possible, and how to actually do it, on the AREDN pages and forums.

Part 4 - Display the Web page

Now, in the mesh status page, next to my node N8GNJ-1, there is an advertised service - N8GNJ Simple Web that is clickable. When clicked, it displays the very simple HTML text that I put in there. What's really unique about this is that it's a web page that's stored on the AREDN node, and it's being served by the AREDN node.

Thanks again Bill!

Update 1 - 2021-02-22 - AR-750 can offer Wi-Fi on 5 GHz in addition to AREDN on 2.4 GHz

In a running conversation I'm having with another Amateur Radio operator, it occurred to me that the GL-iNet GL-AR750 has a unique capability vs other ARDEN nodes because it has a 2.4 GHz radio and a 5 GHz radio. When you flash an AR750 to AREDN firmware, the 2.4 GHz radio is reprogrammed into AREDN's configuration for meshing with other AREDN nodes. But the 5 GHz radio isn't reprogrammed - it remains compatible with Wi-Fi. That capability enables this (theoretical) scenario:

• The big one happens - earthquake, power failure, ice storm, etc. Cellular service is out. This isn't THAT theoretical; I was without cell service for a week in Woodinville WA in the aftermath of a severe winter storm that toppled MANY trees onto the power lines. Power was out for that week, and the small cell sites that service most of Woodinville didn't have standby generators, only batteries, and those were depleted after 12 hours or so.
• People need to communicate their status - email is the most practical.
• A "package" of an AREDN AR-750 with a high capacity battery pack, is put into a tree or other high, central point.
• The AR-750's 2.4 GHz radio meshes with others.
• The AR-750's 5 GHz radio is avilable for access by "civilians". (Yes, this is legal because a ham is in charge of the network - a "control operator".)
• Civilians are able to use their phones to connect to the 5 GHz Wi-Fi Access Point on the AR-750.
• Civilians then open the web browser on their phones and are greeted with a "splash page". That capability requires some development.
• Civilian fills out a form on the web page and then that's upload to a control operator on a laptop somewhere in the mesh.
• Civilian gates out the email into the Winlink system and Winlink handles delivery of the email.