This was an old draft from 2007, and in cleaning up this blog I almost deleted it. But it's actually relevant from a recent discussion, so I decided to dust it off and finish it.
The genesis of this article is a presentation by Scott Currie NS7C - Winlink, Digital Voice and Tech Based Comms - When Infrastructure Fails at the (online) Communications Academy 2021, which I reference in a previous article.
In the past, there was ample discussion about the merits of using Internet connectivity as part of Amateur Radio systems. In places, that discussion is still ongoing. I think that discussion is now moot. Internet connectivity is a requirement of modern life, and Amateur Radio is very much a facet of modern life, thus using Internet as part of Amateur Radio systems is usually a given.
One of the most prominent uses of Internet connectivity in the US is interconnecting Digital Mobile Radio (DMR) repeaters. Another such use is "personal hotspots" instead of connecting directly to a repeater via radio. There are many, many other uses of Internet connectivity in Amateur Radio.
While I think that Internet connectivity in Amateur Radio systems is a given, I also think it's a valid discussion about how dependent Amateur Radio systems should be on Internet connectivity. Specifically, thought should be given to the possibility of failure of Internet connectivity. One reason that not much thought is given to the possibility of failure of Internet connectivity is that Internet connectivity is a complex topic. Amateur Radio is all about the radio (not Internet access), and most people, including most Amateur Radio operators assume that Internet access is an omnipresent utility akin to commercial power. We as Amateur Radio operators give ample thought to the possibility of power failure, which backup battery systems and generators. We even do the annual Field Day exercise / contest which is built around the assumption that commercial power has failed and you must be able to communicate using alternate means of power. But we usually don't give the same level of thought to the possibility (eventuality, actually) of Internet access failure, which can cripple Amateur Radio systems that haven't planned for loss of Internet access.
Before I start discussing Internet robustness / reliability, permit me a small rant. It drives me nuts when I hear someone worry about planning for "The Internet Being Down". Whenever someone says that, it's obvious that they have no conception about what the Internet actually is. The Internet, literally, is a network of networks. While one network (such as your cable system) might go down, or especially individual access methods might go down, the Internet as a whole remains functional. What you have to plan for is any individual method of Internet access going down.
The first decision point about the robustness / reliability of Internet access is should you care? How important is the service or system? For example, using a personal hotspot for chatting with your buddies where you used to live isn't an important service or system (except to you personally). Thus, if you lose Internet connectivity to your personal hotspot, it's no big deal, and thus the reliability of the Internet connection used for the personal hotspot also doesn't really matter.
But if the service or system you're providing is important, then you need to think about and plan for potential failure of the Internet access your system depends on. There are three things you can do:
- Use a form of Internet access that is (reasonably) robust, or
- Have backup or redundant methods of Internet access, or
- Ensure that the Amateur Radio system can continue to operate without Internet access
Or you can do all three (but that's hard, and expensive).
Reasonably Robust Internet Access
One form of reasonably robust Internet access is to use commercial or government Internet access that's engineered to be reliable, such as Internet at an Emergency Operations Center (EOC). Typically connectivity at such facilities that couldn't / shouldn't go down uses multiple methods of Internet access like microwave plus fiber from multiple providers, with the idea that any one failure doesn't result in a complete loss of connectivity.
Another form of reasonably robust Internet Access is satellite. Satellite Internet Access such as Viasat and HughesNet that use geosynchronous satellites have gotten a (justifiably) bad reputation during the demands of COVID-19 working / schooling from home in 2020 and 2021. Those issues are real, mostly for realtime communications such as video conferences. But if your primary usage is non-realtime, such as sending email, providing Internet connectivity for, example, a Winlink gateway, geosynchronous satellite Internet access should work fine.
A better, newer form of satellite Internet access is Starlink. In contrast to geosynchronous orbit, Starlink uses many more satellites in low earth orbit, which solves the latency issues. The Starlink "ground terminal" (named Dishy McFlatface) uses a motor to orient itself to the optimum angle to track Starlink satellites at that location, and then phased array antenna technology to track the individual satellite. Starlink broadband speeds often exceed 100 Mbps downlink / 10 Mbps uplink, at latency good enough for seamless videoconferencing. At the time this article is written, Starlink is in "beta testing" but commercial service is scheduled for "late 2021" for anyone who wants Starlink service (in rural areas of the US, and eventually the entire Northern Hemisphere).
Geosynchronous satellites have a slight advantage over Starlink in that the earth station used for geosynchronous satellites can be some distance away from the user, so likely not affected by any local or regional disasters impacting the user terminal. In 2021, Starlink uses a "bent pipe" architecture where the earth station and the user terminal have to be within the same (smaller) footprint of the satellite the user terminal is connected to. Thus, Internet connectivity via Starlink could potentially be impacted by a regional disaster.
Another form of reasonably robust Internet access is microwave links. Amateur Radio uses three different "flavors" of microwave links:
- HamWAN - Engineered, static links and networks using modified Wireless Internet Service Provider (WISP) equipment to use Amateur Radio spectrum at 5.9 GHz and no encryption
- AREDN - Ad-hoc, dynamic links and networks using using modified Wireless Internet Service Provider (WISP) equipment to use Amateur Radio spectrum at 2.4 GHz and 5.9 GHz and no encryption
- "Part 15" devices - Engineered or ad-hoc, static or dynamic links and networks operating in license-exempt (Industrial, Scientific, and Medical - ISM) portions of spectrum and thus acceptable to use encryption. There are low-end devices that are essentially modified Wi-Fi access points, and high-end devices that don't use Wi-Fi protocols and are intended for use by Wireless Internet Service Providers (WISPs) and thus require some expertise to install and manage.
Backup or Redundant forms of Internet Access
Robust Internet access can be achieved by using commercial Internet (such as a cable modem) and a secondary form of Internet access (such as microwave or satellite, discussed above) and failing over to microwave or satellite when the primary Internet access fails.
Ensure that the Amateur Radio system can continue to operate without Internet access
I think this is the best approach; in my opinion Amateur Radio should be capable of providing robust communications without requiring Internet access within the zone of a disaster. This is called "The edge of the disaster" theory and posits that most disasters are localized. Within the zone of a disaster, normal communications will likely be disrupted. Outside the zone of a disaster, normal communications are available. Thus, the job for Amateur Radio (and any "emergency communications system) is to "bridge" communications to the edge of the disaster, and "hand off" communications to normal communications as soon as that's a viable option.
For example, a DMR repeater that's within a zone of disaster should function normally (RF access via radio) without Internet access.
Thanks for reading!
Steve Stroh N8GNJ
Bellingham, Washington, USA
2021-04-21
Copyright © 2021 by Steven K. Stroh
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