Lately I have been hearing quite a bit about “off grid”, particularly on the subject of Amateur Radio. It might be surprising to some that perhaps a mode or modes used in Amateur Radio are not completely “off grid”. Some of these modes might actually depend partially or entirely on infrastructure.

Before going any further, it would be helpful to define what “off grid” means. The most common and general meaning of this term can be described as:

“without using or depending on public utilities, especially the supply of electricity”

https://languages.oup.com/google-dictionary-en

However, I would like to expand on that definition as follows:

“without using or depending on public utilities or infrastructure, especially the supply of electricity and/or wired networks such as telephone or the internet”

N1UGK

As we begin the year 2024, we have more modes of communications available to us than we did post WWII when SSB first made its way into Amateur Radio by way of surplus radio equipment. For example, we now have more recent modes such as DMR, Echolink, Winlink, Wires-X, D-Star, and many others.

Often times these modes have portions of the communication pathway that rely on infrastructure. They may rely on the internet (public), or dedicated relay networks (private). This in turn relies on electricity from the grid to power the data center(s) or computers and network switches to carry the traffic.

“Real” Amateur Radio

Similar to the subject of “off grid”, I often hear “That’s not real amateur radio!” with respect to some operating modes.

The Amateur Radio hobby primarily centers around “radio”, or RF communication. Early Amateurs would communicate from station to station with morse code (or “CW” for Continuous Wave) over long distances without any infrastructure in between. The only dependency on the grid was electricity. As radio became more advanced, phone became a popular mode, either via AM or SSB over HF.

Personally, for me, I prefer any mode that involves direct RF communication without any 3rd party links, relays, or internet involved. Being able to communicate half way around the globe or further using nothing more than 100 watts (or less) and a wire is what makes the hobby rewarding and keeps it interesting.

Of course repeaters, Winlink, Echolink and other modes are conveniences that fill the gap when traditional modes are unavailable or not possible.

Hidden Dependencies

Radios have become smaller, lighter, and more energy efficient since the early days of CW. These days, transceivers can operate from batteries for example. This makes radio a truly “off grid” option for communication, especially if solar recharging is available.

Technology continues to evolve and improve capability, efficiency, and portability one one hand, but on the other hand it has added dependencies on infrastructure in many cases. These recent technologies could add dependencies that the operator may not be aware of. Perhaps the operator is aware of them, but has not given it much thought.

Recent technologies (All Star Link, Echolink, Winlink, Wires-X, D-Star, DMR Talk Groups) such as internet based relaying or Voice Over IP (VOIP) have added some dependencies for the communication from station to station. In many cases, the dependency is on the internet. If the internet is unavailable, then that point to point communication is not possible. Further, wired networks require electricity from the grid for sustained communications to occur.

The more dependencies that a particular communication pathway has on infrastructure, the more difficult it is to use that pathway when infrastructure is under stress or unavailable. Further, more dependencies means higher probability of failure (see Failure Mode and Effects Analysis).

Most Basic Communication Pathway

As a reference for all possible communication pathways, a most simple example needs to be defined. Two stations communicating via RF only, either by phone (voice) or by CW is the most basic reference communication pathway. It does not require a computer for encoding or decoding, it does not require internet or a wired network for any part of the pathway, and it can be deployed ad-hoc. This method of communication can work over both short distances and long distances. It can even be used to relay messages completely around the world.

This communication mode is most certainly possible today with nothing more than a battery (with solar charging options), a long wire, and a pocket sized QRP transceiver. In fact, those that activate parks (POTA) practice “off grid” ad-hoc setups regularly to make contacts. I would argue that this is truly “off-grid” communications, especially if using solar power for keeping batteries topped-off. There would be no reliance on the internet or electrical grid to keep operating for days, weeks, or months.

Newer modes can be compared with this reference example in mind.

Winlink – Global Radio Email

One of the more recent modes available to Amateurs is Winlink. Winlink can be used to send and receive email like messages around the world over RF. It can be used when and where traditional forms of communication are unavailable, such as in an emergency.

As a fan of Winlink, I like the concept of being able to exchange messages (similar to email) via RF in many places. I can do this over VHF, UHF, HF, or the internet.

Below is a snapshot of the conventional architecture of the Winlink system:

To some, Winlink’s depencencies on infrastructure might not be apparent. For example, the need for CMS servers would render the entire system unusable if they become unreachable, either due to loss of the server(s), power, and/or the internet. Unless the RMS servers can operate in an ad-hoc mode should the CMS be unreachable, Winlink cannot operate “off grid”. RMS servers themselves can also go offline for the same reasons.

Any part of the communication path which requires a computer for processing and/or storing messages adds the requirement for more power from either the grid or batteries.

Luckily, Winlink can operate in “radio only” mode, peer-to-peer mode, and in a hybrid mode. This provides for a robust infrastructure that can adapt to changing conditions. However, use of Winlink in any mode does require a computer in addition to a radio.

Packet Radio

An alternative to Winlink would be the underlying protocol most often used for Winlink connections. Packet radio (AX.25 for example) can be used peer-to-peer, relay, or in a host / client environment. Many hardware TNCs have a built in PBBS which can store and forward messages. These TNCs are often small and require little power to operate (far simpler than a computer for example). A tablet, calculator, vintage computer, or smartphone can be used to connect to TNCs for a terminal interface.

Packet radio is currently used over short distances (on VHF and UHF for example) as well as over long distances (on HF for example). I favor this form of electronic communication because it is truly point to point over RF, requiring little power and no infrastructure at all. Ad-hoc networks can be set up for relaying if needed, and this method of exchange is not reliant on centralized servers to exchange messages.

With simple hardware or software and an HF rig, worldwide chat and/or messaging is not only possible, it’s alive and well today. Network 105 is one example of a group established to help others get on HF packet.

Another use of packet radio is APRS, which can operate independently from any internet connection or repeater gateways. APRS can be used for close range contacts, positioning, and messaging. Many HTs and mobile rigs have APRS built in.

RTTY, PSK31, JS8Call

Digital modes which allow keyboard to keyboard communication have been popular since RTTY and continue to be popular today.

Digital modes such as RTTY, PSK31, and JS8Call allow for direct communication over long distances (using HF). Even though RTTY can be done with many TNCs, the others require a computer for the modulation/demodulation.

Of course all of these require a terminal interface, even when using a TNC. However, these can all work “off grid” provided your terminal and/or computer can run indefinitely on batteries and solar power.

Although RTTY and PSK31 are keyboard to keyboard modes, JS8Call provides additional mechanisms to “store and forward” messages, similar to PBBSs in TNCs. This does not require centralized servers for the “store and forward” messaging capabilities.

Echolink

Another newer technology available to Amateurs is Echolink. Echolink can bridge the gap between repeater sites by using the internet to link two or more sites together. Or, Echolink can be used on a computer or smartphone to connect into a repeater, allowing an Amateur to participate in a conversation that they could not do via RF.

However, as illustrated in the diagram above, an internet link is required between nodes, or between a computer or smartphone operator and at or near the repeater site. If that connection were to become unavailable, the link would be broken.

Of course, Echolink does require a smartphone or computer and an internet connection at both ends. Echolink is one of these modes that relies entirely on the grid.

Repeaters

Perhaps the most overlooked infrastructure in communication pathways is the repeater. Repeaters provide increased coverage area over simplex, but they require power. Some repeaters may have generators and/or batteries to continue operations if the electrical supply were to be interrupted. This type of backup power does not last forever, and unless solar power is available at the repeater site, provides only temporary communication off-grid. If repeaters are linked via the internet, and if that link were to be broken, then the coverage area is reduced.

In addition to power, repeaters do not function all that well if their antenna towers collapse. Natural disasters can render a solar powered repeater useless if the antenna is damaged in any way.

Your local repeater(s) may not work off grid, and if they do, it is most likely for a short period of time before the batteries or generator run out of reserve power.

DMR / System Fusion / Wires-X / AllStar / D-Star

Some of the most popular modes include DMR, Wires-X, and D-Star. Although these involve both an RF protocol and a network component, it is the network component that renders the communication method useless without infrastructure.

For example, most of these protocols have matching “networks” that bridge repeater sites and/or talk groups together. Most often these links are over the internet. If the link is broken or the server(s) are lost, then the network is rendered inoperable.

I often hear Amateurs talking about contacts they’ve made in other countries over DMR or Wires-X, and I often wonder how different that is compared to having a chat over an internet based voice protocol, or chatting over the phone. Both require the internet (or a wired network) for most of the communication pathway between the two points. I also wonder if the operator is thinking that is a “DX” contact similar to one made over RF.

Needless to say, these communications methods require quite a bit of infrastructure and planning to work.

These are good examples of contacts and communications methods that absolutely cannot be done “ad-hoc”. Networks need to be configured, talk groups or reflectors need to be defined and configured, and radios must be preprogrammed (in the case of DMR).

These digital modes are really two parts, one part RF and one part networking over the internet or private networks. Each mode’s RF protocol is independent of the networking portion of the mode. For example, the RF protocols for DMR, C4FM and others can be used for direct communication.

PoC Radios

PoC radios are similar to the old Nextel phones. They have a PTT button and appear to be traditional two way radios. However, they really operate over cellular and/or WiFi and almost none of them work directly.

This is almost as bad as it gets for two way communication in terms of reliability in an emergency. Not only do these not work off grid, they likely will not work during an emergency.

As we’ve seen during 911 and other emergencies, cellular networks favor emergency communications and public service over consumer cellular service. For example, during an emergency, a cellular network provider will in fact prioritize first responders and other public service agency traffic over consumer cellular traffic.

Further, the providers who offer PoC service are similar to MVNOs in that they are running on the very same commercial cellular networks, and their traffic is even lower priority.

Lastly, the PoC systems rely on servers to handle and route the PTT traffic and are likely not as redundant as other commercial services.

Final Thoughts

In consideration of all of the various technologies we have at our disposal, the only truly “off-grid” form of communication over both short and long distances would be a solar and battery powered HF transceiver operating in either CW or SSB mode. If the station can operate on completely renewable energy (such as a battery with solar charging), and does not require a network connection or infrastructure, then it is truly “off-grid”.

I’ve mentioned only a few examples of different modes in this post, but the concept of discerning whether a particular mode is truly “off grid” applies to them all the same.

I am in no way suggesting that any mode of communication is any “better” than another. However, it’s important to think about the dependencies for each mode you use and how it may or may not work off-grid or during an emergency or disaster.