Comment by modeless
1 month ago
It's criminal that cell phones are bristling with incredibly advanced radio technology and yet they are by law not allowed to communicate directly with each other over a distance of more than a couple hundred meters without assistance from a licensed and centrally controlled base station. Meanwhile a $10 walkie talkie using primitive stone-age radio technology can go many miles with zero infrastructure, but by law is not allowed to be used for data transmission. This is a choice our governments have made, not something inherent to the technology.
I’ve been tangentially involved in experimenting with Meshtastic and trying to scale it for large events like Burning Man, on the order of 2000–3000 nodes on a single frequency.
Node to node mesh communication is cool and it works surprisingly well at small scale, but the moment we brought high powered repeaters online the difference was night and day. Coverage, reliability, and usability all jumped instantly.
It makes the tradeoff really obvious. Mesh is great for bootstrapping and local traffic, but once you care about real data propagation at scale, centralized infrastructure wins almost every time. Airtime is scarce, coordination matters, and having a small number of well placed high sites beats thousands of mediocre relays.
I still think there’s room for novelty P2P protocols, but mostly as an optimization layer on top of infrastructure, not as the foundation. Every time you push on this problem hard enough, you end up rediscovering the client router model for a reason.
Of course there's no reason to use a mesh when infrastructure is available. That's not why a mesh would be useful. But it doesn't even need to be a mesh to be a useful feature. Walkie talkies aren't a mesh and they remain useful.
On the other hand a "high powered repeater" for Meshtastic is just the same board with a bigger more optimised antenna.
You can get solar powered ones for under 100€ and slap them wherever you want pretty easily. (But please don't unless you know what you're doing, adding useless router nodes makes the network worse, not better)
A small USB pluggable module that supports LoRa plus an app using Codec2 or similar low rate codec for voice encoding could fill the gap, although having it bundled with the phone would make it a lot less cumbersome to use. For non phone portable solutions, the LilyGo T-Deck Plus/Pro come to mind, but they're not phones so that would imply a 2nd device to carry around.
Yet compared to the 5G radio that can do gigabit speed and 20+ kilometers of range....
But needs towers, which in some disaster situations could be not working, or in others simply not trustworthy. If 5G phones radio modules were modified to allow point to point communication, the usable range would still be a small fraction of what is attainable with towers and their high gain antenna arrays.
The issue with this is that the entire architecture trades energy consumption on the eNodeB side for the handset side. One could make a cell phone where one handset was the eNB and one the handset (and, contrary to the parent post’s claim, there would be no issue getting this approved in an ISM band), but the one operating in eNB mode would have atrocious battery life.
It also helps a lot to have one side of the transmission up on a tower with a giant high gain antenna :)
why does everyone keep suggesting lora for stuff like this? It could support one gsm connection. Not one per person, but one
> Meanwhile a $10 walkie talkie using primitive stone-age radio technology can go many miles with zero infrastructure, but by law is not allowed to be used for data transmission.
Is this even true?
I still have two Gotennas from before they pivoted to military use cases, and they were legal to use both in the US and in Europe (on different bands auto-configured via GPS, as far as I remember).
REI also currently stocks at least one set of walkie talkies [1] that can relay short messages from smartphones via Bluetooth.
[1] https://www.rei.com/product/240874/motorola-talkabout-t803-2...
Wow, you're right, data is technically allowed on FRS frequencies. I didn't realize that. It's not unrestricted though. There are a lot of regulations that constrain how FRS radios can work, much more than for 2.4 Ghz.
You might have conflated the prohibition on encrypted/coded communication with a blanket ban on data vs. voice. Those frequencies are supposed to be used for public communication, which has been interpreted as a requirement that anyone can listen in (as opposed to any member of the public privately communicating with any other member). See 47 CFR Part 95, plain language voice communication.
These days, I'm not sure anyone would seriously rely on a system that sent only unencrypted point-to-point data, so for that use case your original point stands.
There's also a slice of ISM spectrum available around 900-930 MHz in the US, and Europe has an equivalent one around 860 MHz, which is where the (unfortunately discontinued) Gotenna consumer device used to operate.
Get bought out by military control grid --> Instantly kill popular consumer devices.
Happened to my Iridium satellite messenger (for peace of mind when hiking) too... Fortunately, there are several consumer/civilian alternatives to these.
I guess anything that's useful to regular hikers is potentially also useful to the armed, abroad type of hiker, and these are usually better funded, so I can see why startups like these would pivot.
It's unfortunate, GoTenna was (still is) pretty cool. Beartooth is similar and you can just buy them, but they unfortunately still have military-level pricing for what is pretty simple hardware.
Though in their defense, I'm not sure GoTenna was ever "popular." Probably not enough to pay the bills, given their pivot.
It isn't a law thing, but I'm disappointed that LTE Direct didn't go anywhere. That let's cell phone talk to each other over range up a km. The problem is that there LTE Direct requires implementation in the radio firmware, and the companies only did it for government phones. There is also 5G Device-to-Device and I haven't found out if that is supported more widely. There would also need to be frequency allocation, something CBRS (3.5GHz) would work but would be nice to get something with longer range.
You aren't going to get longer ranges with phone, the power and antenna are too limited. Walkie-walkie have bigger antennas (the stubby FRS sort of suck) and more power. Also, walkie-talkie don't have much bandwidth so the data rates would suck.
It's a business model thing, which seems to supplant law these days. Can't meter P2P. Intermediation to prevent usurpation of network effects is the name of the game in the modern day. No one will say that, but it's the quiet part left explicitly unsaid. The negative space of the incentive structure, if you will.
Will the walkie talkies work if there are hundreds in a small area all transmitting data with each other? Besides, there's just not that much bandwidth there.
The smartphone is just an advanced walkie-talkie, currently limited only by the mobile operator, the law, the radio chipset, and the OS.
In a true emergency, who can stop you from modifying that architecture? Once you treat the device as an independent radio node (using its DSP power to run custom modems) you can establish a mesh network with a range of several kilometers.
We have a '4x4 car in our pockets; we’ve just been conditioned to treat it like a toy.
Not disagreeing with you, but you’re papering over a lot of complexity.
Note that cellular radios are highly specialized and the filtering circuits are tuned to specific bands. It’s not exactly like having a software defined radio in your pocket.
Next, at the modem level, you’ll need to implement and then sideload custom firmware. Finally, you’ll need to expose the right APDUs to the kernel to manage the whole thing.
TBH it sounds like a fun side project, but my point is you need to repurpose a lot of different parts of the stack to accomplish what you want.
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The smartphone is talking to a highly sensitive receiver fed by a large sensitive antenna listening carefully in the direction of the smartphone. The base station is transmitting back a carefully directed beam with orders of magnitude more power than a smartphone. The system is highly asymmetrical. Ohh and maybe there is not one but many base stations talking concurrently to the smartphone so that if one looses some data the flow is maintained.
Since I’m not able to edit my original comment: rm30 is actually referring to something much more interesting than jailbreaking the LTE/NR stack.
> For instance, many chipsets have an integrated FM receiver that is essentially a high-sensitivity VHF radio.
Walkie talkies as licensed today wouldn't because they are required by law to use exclusively stone-age radio technology. But modern unlicensed radio technology is incredibly good at sharing scarce 2.4 Ghz spectrum. Sometimes devices do interfere with each other, but they remain useful and they are far better at sharing than any expert would have predicted years ago. Let the radio engineers try.
It is not as easy as you think.
RF attenuation is proportional to frequency and at 2.4 GHz, it is very high. Also, the distance over which one could communicate depends on antenna height, so if both parties are at ground level, it is not feasible over a few hundred meters unless both are in wide open space.
Source: ham operator who has played with long distance device to device communication without using a repeater.
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This is great on paper until some jackass wants to access their home NAS over the public frequency range so they can watch anime all day at their desk, which only works when they use multiple channels at once.
There are tons of cool things society could enjoy if it wasn't for a small handful of shameless actors.
Please site the relevant sections of this supposed law you claim exists.
Or even better, where is the tech that can do this disregarding the law? Let's not act that something being illegal never stopped it from achieving mass adoption.
Well obviously cell phones have very powerful tx/rx so my question would be "what is stopping us from using this for p2p", I assume the answer is we don't have software access to the radio, and I assume that's for regulatory reasons but idk
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Many WiFi chips can be put into monitor mode (process all the data packets it can detect over the air) and inject packets for transmissions themselves. This pathway is typically unoptimized and would offer poor bandwidth but it is enough for text and audio.
You would need root to do this, and implement your own protocol on top of it with forward error correcting codes.
Personally, the additional complexity and overheads required for a P2P phone network is not worth while and I'm not sure it would fix that many problems that haven't already been fixed with walkie talkies.
Not worthwhile? “It’s too hard” isn’t a great argument for why our phones should just become useless during power outages, natural disasters, ..
It’s not “too hard”. It’s physically impossible without regulation. There is but one limited RF spectrum that we all share. One bad actor (intentional or misconfigured) can render the entire RF spectrum in their area unusable. The radius of their impact only depends on how much kWHs they have access to and it doesn’t take much to cripple radio communication in a large metropolitan area.
Until some clever cookie can figure out some way to utilize string theory’s extra dimensions for sending signals and then every body can have their own dimension to mess with, collective regulation on broadcasters is the only feasible way.
Nothing is stopping you from getting an HT for communication during power outages, natural disasters, etc. You just have to get a license to make sure you don’t actively harm everyone who is sharing the same spectrum with you especially during said natural disaster.
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Not worthwhile to who?
The point is exactly that everybody is carrying a phone, but almost nobody is carrying a walkie-talkie. And why should I carry one more thing? My smartphone has already replaced my music player, camera...
It’s one less thing to have to buy and carry and charge and configure and remember and get others to do the same.
A alternative example of this is how Apple doesn't have a way to browse your iPhone's gallery without syncing to their super slow iCloud first.
There is nothing stopping a phone manufacturer from putting a 900 MHz ISM radio in their hardware.
Also, the walkie talkies certainly can legally do data transmission.
HAM radios can transmit data I think. They just can't do encrypted transmissions. (I'm open to correction on this.)
They _can_, they're just not allowed to. It's a tradeoff, they can use higher transmission frequencies than regular folk, but also have to do it in the open.
A walkie-talkie requires a big antenna and consume a lot more power than a cellphone.
Both not true.
Both European PMR446 and the US FRS are limited to 0.5 W; GSM uses four times that. There are walkie-talkies with very small antennas too. The limiting factor is line-of-sight, in any case.
If you're fine with less than real-time audio, you can get much, much smaller and low power.
1) LTE frequencies are in the frequency intervals 600—900Mhz, or over the Ghz. Higher frequency means smaller antennas.
2) 5G cells are small and very dense, this means less power consumption.
3) LTE and 5G are based on CDMA, a technology that is way more efficient in term of bandwidth efficiency than the FM modulation used by a walkie talkie
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Check your sources. The law you claim exists… which one is it?
Ham frequencies would work even better?
File this under "lies that someone said on the interwebs."