I’m a qualified amateur operator. I can operate on any ham bands up to 190W EIRP if I recall my countries regulations correctly.
The issue with doing something like wifi on ham bands technical issues finding radio chips capable of signalling at such a high rate of speed, on bands that are able to be used by hams. There’s also the requirement for hams to identify themselves on air, and the general use of AM/FM and derivative technology on ham bands and general resistance to the OFDM used as the main signal encoding for WiFi. So finding an OFDM capable radio transmitter/receiver for use in… say, the 2m band (144Mhz … ish) is basically impossible, and there’s no way to identify. You would have to build a new protocol and standard from the ground up and use very modified or rare/expensive radio chips, and likely build the drivers/firmware for it entirely yourself. People with the required hardware, software, baseband, radio, and firmware experience that are hams who want a product like WiFi for ham radio channels is extraordinarily rare.
As for city-wide WiFi/mesh networks: it has been attempted, and has seen some limited success, but doesn’t scale well with the usual protocols. Routing protocols like BGP, OSPF and IS-IS are meant for much larger IP blocks being routed between interfaces. A wireless mesh system would use a single interface (one radio) for both send and receive, which most protocols don’t support, and each “hop” or station on the mesh would only be advertising a single IP (or an extremely small set of IPs) per participating node.
Most routing protocols assume that every node on an interface can talk to every other node on the same interface and thus there’s no need to repeat or relay messages from an interface to the same interface.
There’s also no standards that allow wifi to use multiple channels/frequencies for tx/rx, eg, send on 5.45 GHz, and receive on 5.65Ghz. it simply isn’t something that any WiFi chip is capable of. So full duplex isn’t possible right now.
The common wifi frequencies are also extremely power limited and on bands that are prone to interruption. In the wild, there’s plenty of things that can disrupt 2.4Ghz and 5/6Ghz transmissions. With the power limits, to go any significant distance, you need directional antennas that limit free space path loss so the signal travels further. In the case of wireless internet service providers (WISP, not to be confused with the mobile carriers), they generally use panel or dish antennas to extend the range.
For power output, at the high end, some bands allow for upwards of 5W of directional power, or 1W of omnidirectional power (in EIRP). On the low end, handheld ham radio units start at 5W of power, and can usually attenuate their transmitter to 1W or lower as an option. Household WiFi is usually around 0.1W of power per radio. Even cranking that up to the maximum legally allowed wattage won’t result in covering more than a few blocks of a city with a fairly poor signal overall; that signal is going to be fairly easily blocked, absorbed, reflected, or otherwise attenuated by just about everything, including, but not limited to the structure of your house.
Meanwhile, standing in my home with a 5W handheld transceiver operating on 70cm (440Mhz), I can hit a repeater that’s something like 10 miles away with a nearly perfect signal over FM, without assistance. OFDM signals would likely be scrambled beyond recognition at 2.4 or 5 GHz across that much of a gap, or even one that’s 1/10th as far, with only 1W of legal power, without using some kind of directional antenna or antenna array.
Don’t get me wrong, well configured wireless can go so far that you have to account for the curvature of the earth, but they’re always very very directional, using dish antennas or similar.
Don’t get me wrong, the ideas are great, but the challenges faced are enormous. It can quickly turn into a lifelong project to get something functional, and even then, there’s no guarantee that it will ever catch on as a product. The limitation for ham operators regarding encryption is problematic when it comes to data communication as well, since just about everything that’s data-driven on the internet implements SSL. Computers and systems expect encryption all over the place and bluntly, those messages cannot be sent over ham bands. There’s nuance to that regulation, at least in my country, but I won’t get into the fine print here.
Even so, there are some crude digital modes used by ham operators which are normally voice encoding or plain text encoding. Uses are limited on purpose. If you’re interested in longer distance emergency communications you could look into LoRA, which is relatively new.
There’s a lot more to say on this, but bluntly, I’ve said enough. It’s all interconnected, and I love it, but I’m just ranting now.
Thanks for a very detailed explanation! So it seems that this is almost impossible. Except for maybe a small part of a city.
The lack of encryption, privacy and anonymity in HAM radio would be an issue for me. Just like in mobile phones. But since you can use end-to-end encryption over WiFi (and some weaker, less useful encryption is used in mobile phones), maybe there are exceptions. I’ve heard of LoRA, but I wouldn’t want to use it, unless I’m allowed to encrypt the messages. It also seems that the message length is very limited, so using something like PGP might not always be possible.
Well, for basic WiFi to dramatically extend coverage, you would need to take a page from the WISP/mobile carrier playbook and set it up with semi directional panels, in a configuration that covers 365 degrees. Placing the units high up on a tower, angled down slightly, with their power levels as high as they can go.
Primarily using 2.4Ghz would provide better penetration of signals in the area, but there would also be more conflicts.
Still, as I’ve said, even in this configuration, you may get a few blocks of coverage at best… At least to a regular device with an Omni antenna, like a phone or laptop. The only way to extend any further would be to use directional antennas on both sides, which is what WISP companies do. In that case, you can generally transmit to anywhere in line of sight of the base antenna system. Being very high up vertically becomes a more significant factor since there’s plenty of buildings, trees, and other obstacles that are going to block the communication. As I mentioned, at extreme range, you’re going to contend with the curvature of the earth itself, so that’s something to bear in mind when going very very far with it.
Regulations allow for the public to use 2.4/5 GHz as well as 900mhz and, I believe, 430? MHz? There’s higher frequencies like 60Ghz, but at that wavelength, you start to see scattering and attenuation from atmospheric events like rain and fog. Those things still affect 2.4 & 5Ghz, but usually not significantly enough to cause a failure in the link. The ISM 5.8ghz band may be a good place to go for high speed data, but for simple (slow) data, 2.4 GHz will be more reliable.
The regulatory bodies that govern frequency use are fairly strict when it comes to what can be done without a license. The only way to guarantee that you can do pretty much whatever you want would be to request a frequency for your own uses from your local regulatory authority (in the US, it’s the FCC, in Canada it’s IC or industry Canada, other countries will have similar government organizations to manage the EM/RF airspace). With a license you may have power restrictions based on the area you intend to serve (they don’t want you blasting the signal so strongly that you encroach on other licensed people legally using their system in their area), but you should be free to use any mode (analog, digital, data, etc), with any level of encryption you want, and grant permission to anyone else to use the frequency in your designated area. This is how mobile providers operate, but usually they’re buying large bands of frequency ranges for use across the entirely of a state/province/country, so their pricing is well into six figures. It’s not cheap to get such licensing, likely well into the thousands per year, even for a modest area with a small frequency range. Additionally, your name goes on the license, and that’s usually made available to the public, though few ever actually look at that data, it is available nonetheless. You can otherwise anonymize the transmissions and encrypt the messages to your heart’s content. The challenge there is that everything that can transmit on those licensed bands is extremely expensive; since usually only businesses with direct need for such systems ever apply for a license like that. The only places I’ve known to use a licensed RF system have been physically large places, like airports (security, airlines etc.), large campus style institutions like universities and colleges, and parks services (even as small as water parks) many smaller businesses are illegally using FRS and GMRS for in-store communication; places like your local hardware store may do this. Larger franchise places are a mix of purpose built communication systems, like with the headsets commonly used by fast food restaurants, which are very short range and that is counterbalanced by the illegal use of residential systems like FRS for the same purpose.
Unlicensed residential communications like FRS are usually very short range and very power restricted, and the legislation (at least here) usually stipulates that they are only to be used for personal communication, not professional/business communication; so the use of such services in a commercial environment is illegal.
However, enforcement is usually not very strict, and businesses do it anyways, and likely don’t get punished for such abuse of those systems because nobody is enforcing the rules against it. Businesses know that enforcement is poor and often disregard the potential risks of using those services illegally.
I know ham operators are generally very adamant about people following the rules and I’ve heard many stories of individuals thinking they can just use ham bands without proper identification or qualifications without consequence, much the same way as businesses do with FRS, but licensed operators have and do, track down such use and report it, and that’s about the only time I’ve heard that people get punished for their illegal use of frequencies and bands… when it is reported directly to the FCC/IC/whomever is in charge of the allocations. The only instances of reports that I’ve heard are from ham operators and city services like fire departments when you illegally broadcast on their channels.
Most of the unlicensed frequencies are generally the wild west of radio, and all manner of strange and unusual happenings occur on those bands. It’s usually few and far between that you’ll experience it, but it happens and often, nobody has the skill or care, to bother reporting it. Nonetheless it is illegal to broadcast over the frequency power limits and the penalties for being caught are steep, up to and including jail time; so it’s not something I would ever endorse. Regardless, you have been warned. Check your local laws from your regulatory authority and ensure you are complying with laws before turning on any transmitter (listening to any/every frequency is generally not restricted, though, understanding the transmissions is usually an issue, especially with digital/encrypted communications on licensed frequencies). YMMV on this.
Regardless of all of that, if you wish to pursue an emergency or wide spread communications system for data, including encrypted data, I wish you the best of luck. I’m happy to lend a hand and experiment along with you if you desire it. I’ve always felt that exclusively relying on primary communication systems, like mobile phone systems and public switched telephone networks (things that otherwise rely on infrastructure) is an inherent weakness. I’m an IT person by day, with specialty in wireless and networking technologies, so you’ve struck a chord here. I’m very interested in any data communication that can be used during a primary infrastructure failure. Personally I experienced the full force of such a failure a few years back when one of the major telecommunications providers in my country had a significant/system wide communications break down for more than 24 hours. I was a mobile subscriber to their service, and for that day, I was unable to use any data services on my cellphone, nor make our receive any calls. It was a wake up call that if there’s a large scale failure of the system I relied on, then I would be dead in the water in terms of being able to get help in an emergency. At the time I didn’t have my ham license, and I was unable to even check and make sure my loved ones were okay while I was away from a working WiFi connection. At the time I was traveling to work, and while on the road I was entirely communications blind. Something I haven’t experienced for nearly 20 years. Unfortunately, I’m the only person in my family to have achieved my amateur qualification, but I can at least request that someone with a working connection call and talk to someone (over the radio), if such an event reoccurs. Having a method to communicate with them in the event of another such failure without requiring them to go through the amateur qualification would be something very desirable to me.
I was thinking about this WiFi idea, because I think it could be useful in case of an emergency. I think there should be services hosted inside of cities. I mean in their local networks. It could be local government websites and maybe things like a Lemmy instance where people could talk. Even stuff like Open Street Map could maybe be useful. So if the city was for some reason cut off from the internet and the mobile network, most people would still be able to communicate and have access to information. It would be like having a tiny backup of the internet (at least whatever is possible to self host). I think it’s a big oversight to only rely on the internet.
Something like this could maybe be also useful in countries with authoritative governments, which sometimes cut off internet access in the entire country. In the long term the government would probably find out and try to stop it, though.
But as you’ve explained, making something like this would require many people working together and ideally should probably be handled by a local government instead. It’s not something I plan on doing, it just seemed like a cool idea to think about.
I might try playing with LoRA for some other project some day, if I can legally use it without a license. But if I can’t encrypt the messages, then I would probably prefer to use WiFi (for short distances) instead.
In your case, to have emergency communications with your family, maybe CB radio or satellite phones would be a solution?
Much of the internet is both centralized and not. It was designed with redundancies in mind, so it can route around disconnections. The centralization part of it is that services like your ISP generally are very centralized to datacenters, so something “in city” may not be able to be accessed without the closest datacenter or internet exchange being online, each of which has multiple redundancies.
The only good way to do it would be over a city-wide public wifi that has all of the self-hosted information on the locally connected network. Only on that wifi network could you get access, since that system would be linked back to the internet/ISPs via the internet exchange or datacenter.
It would be an ambitious project. The AMPRnet is one such emergency wifi network. It requires a ham license but it’s all wifi based long distance communications. The ham license is for authorization to operate on the network, not a legal/technical requirement. They just won’t let non-hams connect.
People host all kinds of things on there, so it’s fairly robust overall.
As for emergency communications, in an actual emergency (risk to life and limb kind of deal) any person, whether qualified or not, has legal permission to use any radio they find. My family knows this. My concern is that they won’t know how to switch to a useful channel when such an emergency happens. I have several handheld radios, so there are a few around that they can grab. If I’m heading out of town with them, I try to bring a few, so if an emergency happens while we’re away, I can program and hand off a radio, and we can stay in contact if we need to split up at all during the emergency.
For everyday communications in a primary communications outage, we have some FRS radios which don’t require a license. They’re much shorter range, but would be useful to have in a pinch.
There’s a lot of decent options.
I’m actually looking into setting up a LoRA node, or something similar because there’s a spec that I came across for a mail detector IoT thing. It’s low power and uses LoRA. It should last several months on a fairly modest battery. It should be able to relay to us when mail is detected so we can go get it from the community mailbox thing when it is delivered. I should be able to tie it into our home automation stuff and just send out notifications when we need to go get it, or change the color of lights or something.
It will be my first step into this kind of thing, so I’ll see how it goes.
I haven’t heard of AMPRnet before. Sounds interesting.
As for emergency communications, in an actual emergency (risk to life and limb kind of deal) any person, whether qualified or not, has legal permission to use any radio they find.
I wasn’t sure about that, so that’s good to know!
Mail detector sounds like a perfect use for LoRA. But I suspect that there is no security by default and anyone would be able to send you such a message if they were mean :).
I’m a qualified amateur operator. I can operate on any ham bands up to 190W EIRP if I recall my countries regulations correctly.
The issue with doing something like wifi on ham bands technical issues finding radio chips capable of signalling at such a high rate of speed, on bands that are able to be used by hams. There’s also the requirement for hams to identify themselves on air, and the general use of AM/FM and derivative technology on ham bands and general resistance to the OFDM used as the main signal encoding for WiFi. So finding an OFDM capable radio transmitter/receiver for use in… say, the 2m band (144Mhz … ish) is basically impossible, and there’s no way to identify. You would have to build a new protocol and standard from the ground up and use very modified or rare/expensive radio chips, and likely build the drivers/firmware for it entirely yourself. People with the required hardware, software, baseband, radio, and firmware experience that are hams who want a product like WiFi for ham radio channels is extraordinarily rare.
As for city-wide WiFi/mesh networks: it has been attempted, and has seen some limited success, but doesn’t scale well with the usual protocols. Routing protocols like BGP, OSPF and IS-IS are meant for much larger IP blocks being routed between interfaces. A wireless mesh system would use a single interface (one radio) for both send and receive, which most protocols don’t support, and each “hop” or station on the mesh would only be advertising a single IP (or an extremely small set of IPs) per participating node.
Most routing protocols assume that every node on an interface can talk to every other node on the same interface and thus there’s no need to repeat or relay messages from an interface to the same interface.
There’s also no standards that allow wifi to use multiple channels/frequencies for tx/rx, eg, send on 5.45 GHz, and receive on 5.65Ghz. it simply isn’t something that any WiFi chip is capable of. So full duplex isn’t possible right now.
The common wifi frequencies are also extremely power limited and on bands that are prone to interruption. In the wild, there’s plenty of things that can disrupt 2.4Ghz and 5/6Ghz transmissions. With the power limits, to go any significant distance, you need directional antennas that limit free space path loss so the signal travels further. In the case of wireless internet service providers (WISP, not to be confused with the mobile carriers), they generally use panel or dish antennas to extend the range. For power output, at the high end, some bands allow for upwards of 5W of directional power, or 1W of omnidirectional power (in EIRP). On the low end, handheld ham radio units start at 5W of power, and can usually attenuate their transmitter to 1W or lower as an option. Household WiFi is usually around 0.1W of power per radio. Even cranking that up to the maximum legally allowed wattage won’t result in covering more than a few blocks of a city with a fairly poor signal overall; that signal is going to be fairly easily blocked, absorbed, reflected, or otherwise attenuated by just about everything, including, but not limited to the structure of your house.
Meanwhile, standing in my home with a 5W handheld transceiver operating on 70cm (440Mhz), I can hit a repeater that’s something like 10 miles away with a nearly perfect signal over FM, without assistance. OFDM signals would likely be scrambled beyond recognition at 2.4 or 5 GHz across that much of a gap, or even one that’s 1/10th as far, with only 1W of legal power, without using some kind of directional antenna or antenna array.
Don’t get me wrong, well configured wireless can go so far that you have to account for the curvature of the earth, but they’re always very very directional, using dish antennas or similar.
Don’t get me wrong, the ideas are great, but the challenges faced are enormous. It can quickly turn into a lifelong project to get something functional, and even then, there’s no guarantee that it will ever catch on as a product. The limitation for ham operators regarding encryption is problematic when it comes to data communication as well, since just about everything that’s data-driven on the internet implements SSL. Computers and systems expect encryption all over the place and bluntly, those messages cannot be sent over ham bands. There’s nuance to that regulation, at least in my country, but I won’t get into the fine print here.
Even so, there are some crude digital modes used by ham operators which are normally voice encoding or plain text encoding. Uses are limited on purpose. If you’re interested in longer distance emergency communications you could look into LoRA, which is relatively new.
There’s a lot more to say on this, but bluntly, I’ve said enough. It’s all interconnected, and I love it, but I’m just ranting now.
Thanks for a very detailed explanation! So it seems that this is almost impossible. Except for maybe a small part of a city.
The lack of encryption, privacy and anonymity in HAM radio would be an issue for me. Just like in mobile phones. But since you can use end-to-end encryption over WiFi (and some weaker, less useful encryption is used in mobile phones), maybe there are exceptions. I’ve heard of LoRA, but I wouldn’t want to use it, unless I’m allowed to encrypt the messages. It also seems that the message length is very limited, so using something like PGP might not always be possible.
Well, for basic WiFi to dramatically extend coverage, you would need to take a page from the WISP/mobile carrier playbook and set it up with semi directional panels, in a configuration that covers 365 degrees. Placing the units high up on a tower, angled down slightly, with their power levels as high as they can go.
Primarily using 2.4Ghz would provide better penetration of signals in the area, but there would also be more conflicts.
Still, as I’ve said, even in this configuration, you may get a few blocks of coverage at best… At least to a regular device with an Omni antenna, like a phone or laptop. The only way to extend any further would be to use directional antennas on both sides, which is what WISP companies do. In that case, you can generally transmit to anywhere in line of sight of the base antenna system. Being very high up vertically becomes a more significant factor since there’s plenty of buildings, trees, and other obstacles that are going to block the communication. As I mentioned, at extreme range, you’re going to contend with the curvature of the earth itself, so that’s something to bear in mind when going very very far with it.
Regulations allow for the public to use 2.4/5 GHz as well as 900mhz and, I believe, 430? MHz? There’s higher frequencies like 60Ghz, but at that wavelength, you start to see scattering and attenuation from atmospheric events like rain and fog. Those things still affect 2.4 & 5Ghz, but usually not significantly enough to cause a failure in the link. The ISM 5.8ghz band may be a good place to go for high speed data, but for simple (slow) data, 2.4 GHz will be more reliable.
The regulatory bodies that govern frequency use are fairly strict when it comes to what can be done without a license. The only way to guarantee that you can do pretty much whatever you want would be to request a frequency for your own uses from your local regulatory authority (in the US, it’s the FCC, in Canada it’s IC or industry Canada, other countries will have similar government organizations to manage the EM/RF airspace). With a license you may have power restrictions based on the area you intend to serve (they don’t want you blasting the signal so strongly that you encroach on other licensed people legally using their system in their area), but you should be free to use any mode (analog, digital, data, etc), with any level of encryption you want, and grant permission to anyone else to use the frequency in your designated area. This is how mobile providers operate, but usually they’re buying large bands of frequency ranges for use across the entirely of a state/province/country, so their pricing is well into six figures. It’s not cheap to get such licensing, likely well into the thousands per year, even for a modest area with a small frequency range. Additionally, your name goes on the license, and that’s usually made available to the public, though few ever actually look at that data, it is available nonetheless. You can otherwise anonymize the transmissions and encrypt the messages to your heart’s content. The challenge there is that everything that can transmit on those licensed bands is extremely expensive; since usually only businesses with direct need for such systems ever apply for a license like that. The only places I’ve known to use a licensed RF system have been physically large places, like airports (security, airlines etc.), large campus style institutions like universities and colleges, and parks services (even as small as water parks) many smaller businesses are illegally using FRS and GMRS for in-store communication; places like your local hardware store may do this. Larger franchise places are a mix of purpose built communication systems, like with the headsets commonly used by fast food restaurants, which are very short range and that is counterbalanced by the illegal use of residential systems like FRS for the same purpose.
Unlicensed residential communications like FRS are usually very short range and very power restricted, and the legislation (at least here) usually stipulates that they are only to be used for personal communication, not professional/business communication; so the use of such services in a commercial environment is illegal. However, enforcement is usually not very strict, and businesses do it anyways, and likely don’t get punished for such abuse of those systems because nobody is enforcing the rules against it. Businesses know that enforcement is poor and often disregard the potential risks of using those services illegally.
I know ham operators are generally very adamant about people following the rules and I’ve heard many stories of individuals thinking they can just use ham bands without proper identification or qualifications without consequence, much the same way as businesses do with FRS, but licensed operators have and do, track down such use and report it, and that’s about the only time I’ve heard that people get punished for their illegal use of frequencies and bands… when it is reported directly to the FCC/IC/whomever is in charge of the allocations. The only instances of reports that I’ve heard are from ham operators and city services like fire departments when you illegally broadcast on their channels.
Most of the unlicensed frequencies are generally the wild west of radio, and all manner of strange and unusual happenings occur on those bands. It’s usually few and far between that you’ll experience it, but it happens and often, nobody has the skill or care, to bother reporting it. Nonetheless it is illegal to broadcast over the frequency power limits and the penalties for being caught are steep, up to and including jail time; so it’s not something I would ever endorse. Regardless, you have been warned. Check your local laws from your regulatory authority and ensure you are complying with laws before turning on any transmitter (listening to any/every frequency is generally not restricted, though, understanding the transmissions is usually an issue, especially with digital/encrypted communications on licensed frequencies). YMMV on this.
Regardless of all of that, if you wish to pursue an emergency or wide spread communications system for data, including encrypted data, I wish you the best of luck. I’m happy to lend a hand and experiment along with you if you desire it. I’ve always felt that exclusively relying on primary communication systems, like mobile phone systems and public switched telephone networks (things that otherwise rely on infrastructure) is an inherent weakness. I’m an IT person by day, with specialty in wireless and networking technologies, so you’ve struck a chord here. I’m very interested in any data communication that can be used during a primary infrastructure failure. Personally I experienced the full force of such a failure a few years back when one of the major telecommunications providers in my country had a significant/system wide communications break down for more than 24 hours. I was a mobile subscriber to their service, and for that day, I was unable to use any data services on my cellphone, nor make our receive any calls. It was a wake up call that if there’s a large scale failure of the system I relied on, then I would be dead in the water in terms of being able to get help in an emergency. At the time I didn’t have my ham license, and I was unable to even check and make sure my loved ones were okay while I was away from a working WiFi connection. At the time I was traveling to work, and while on the road I was entirely communications blind. Something I haven’t experienced for nearly 20 years. Unfortunately, I’m the only person in my family to have achieved my amateur qualification, but I can at least request that someone with a working connection call and talk to someone (over the radio), if such an event reoccurs. Having a method to communicate with them in the event of another such failure without requiring them to go through the amateur qualification would be something very desirable to me.
I was thinking about this WiFi idea, because I think it could be useful in case of an emergency. I think there should be services hosted inside of cities. I mean in their local networks. It could be local government websites and maybe things like a Lemmy instance where people could talk. Even stuff like Open Street Map could maybe be useful. So if the city was for some reason cut off from the internet and the mobile network, most people would still be able to communicate and have access to information. It would be like having a tiny backup of the internet (at least whatever is possible to self host). I think it’s a big oversight to only rely on the internet.
Something like this could maybe be also useful in countries with authoritative governments, which sometimes cut off internet access in the entire country. In the long term the government would probably find out and try to stop it, though.
But as you’ve explained, making something like this would require many people working together and ideally should probably be handled by a local government instead. It’s not something I plan on doing, it just seemed like a cool idea to think about.
I might try playing with LoRA for some other project some day, if I can legally use it without a license. But if I can’t encrypt the messages, then I would probably prefer to use WiFi (for short distances) instead.
In your case, to have emergency communications with your family, maybe CB radio or satellite phones would be a solution?
Much of the internet is both centralized and not. It was designed with redundancies in mind, so it can route around disconnections. The centralization part of it is that services like your ISP generally are very centralized to datacenters, so something “in city” may not be able to be accessed without the closest datacenter or internet exchange being online, each of which has multiple redundancies.
The only good way to do it would be over a city-wide public wifi that has all of the self-hosted information on the locally connected network. Only on that wifi network could you get access, since that system would be linked back to the internet/ISPs via the internet exchange or datacenter.
It would be an ambitious project. The AMPRnet is one such emergency wifi network. It requires a ham license but it’s all wifi based long distance communications. The ham license is for authorization to operate on the network, not a legal/technical requirement. They just won’t let non-hams connect.
People host all kinds of things on there, so it’s fairly robust overall.
As for emergency communications, in an actual emergency (risk to life and limb kind of deal) any person, whether qualified or not, has legal permission to use any radio they find. My family knows this. My concern is that they won’t know how to switch to a useful channel when such an emergency happens. I have several handheld radios, so there are a few around that they can grab. If I’m heading out of town with them, I try to bring a few, so if an emergency happens while we’re away, I can program and hand off a radio, and we can stay in contact if we need to split up at all during the emergency.
For everyday communications in a primary communications outage, we have some FRS radios which don’t require a license. They’re much shorter range, but would be useful to have in a pinch.
There’s a lot of decent options.
I’m actually looking into setting up a LoRA node, or something similar because there’s a spec that I came across for a mail detector IoT thing. It’s low power and uses LoRA. It should last several months on a fairly modest battery. It should be able to relay to us when mail is detected so we can go get it from the community mailbox thing when it is delivered. I should be able to tie it into our home automation stuff and just send out notifications when we need to go get it, or change the color of lights or something.
It will be my first step into this kind of thing, so I’ll see how it goes.
I’m sure I’ll post about it at some point.
I haven’t heard of AMPRnet before. Sounds interesting.
I wasn’t sure about that, so that’s good to know!
Mail detector sounds like a perfect use for LoRA. But I suspect that there is no security by default and anyone would be able to send you such a message if they were mean :).
Generally with mail, someone could just trigger the detector too… Heh.
True :D