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A decentralized peer-to-peer messaging application that operates over Bluetooth

bitchat.free

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Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#291

Post by catlifeonmars »

rm30 wrote: post #289
catlifeonmars wrote: post #279

Earlier quoted context omitted.

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.…

I was pushing on the walkie-talkie case to gain the maximum results from existing phones, that's a true emergency case. You’re absolutely right that the 5G/LTE baseband is a black-box nightmare to repurpose. But I’m not looking to hack the cellular modem; I’m looking for the dormant '4x4 car' already available. For instance, many chipsets have an integrated FM receiver that is essentially a high-sensitivity VHF radio…

> For instance, many chipsets have an integrated FM receiver that is essentially a high-sensitivity VHF radio. By taking the raw audio output and applying a Software Modem (AFSK/FSK) in the user-space, you bypass the kernel/firmware complexity entirely. You don’t need to sideload a modem driver if you treat the audio jack or the internal FM bus as your physical layer.

This is fascinating. Happy to do the research myself, but do you have any recommended reading/sources to learn more about this?

Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#292

Post by bri3d »

londons_explore wrote: post #271
squarefoot wrote: post #238

Earlier quoted context omitted.

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....

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 :)

Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#294

Post by ianburrell »

modeless wrote: post #217

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…

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.

Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#296

Post by rm30 »

ssl-3 wrote: post #276
rm30 wrote: post #244

Earlier quoted context omitted.

I’ve read all the posts and, as the 'old man of the village', I would suggest taking a look at FidoNet. It was running 40 years ago, for more than a decade, before the internet was available to the average person. Store-and-forward, hierarchical organization, scheduled transmissions, working over dial-up and radio links, everything is there. There is nothing new to invent, and it was far more reliable than the 10m re…

FidoNet has a lot of it solved, for sure. But doesn't it rely upon pre-configured paths between nodes in order to handle message routing? If so, then: Wouldn't it fall down completely when operating in the ever-shifting and inherently disorganized environment that a sea of pocket supercomputers represents?

I don’t take concepts as a 'full package'. I evaluate what is worth taking based on the requirements. The brilliant part of FidoNet is the asynchronous persistence.

In a 'sea of supercomputers,' a real-time mesh (like Bluetooth) fails because it requires an end-to-end path right now. Store-and-Forward allows a node to hold a message until it 'sees' any valid peer, turning every 'meat-bot' into a mobile post office.

My main concern with this entire discussion is the reliance on Bluetooth to achieve the result.

If we truly want to build a free and open intercommunications system, we must put all ideas on the table, establish clear targets (a doomsday system or inviting a friend for a drink), and evaluate what is truly available versus what is not.

Only from that foundation can we begin to define a project that survives the real world.

Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#297

Post by lormayna »

lxgr wrote: post #242
lormayna wrote: post #237

Earlier quoted context omitted.

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

Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#298

Post by ShroudedNight »

throwaway758439 wrote: post #114
behnamoh wrote: post #21

Earlier quoted context omitted.

In Iran right now... Internet shut down while the regime keeps slaughtering people at the order of 4x9/11.

Internet is exploited by US as a tool for regime change [1] in coordination with sponsored on the ground terrorism. [1] [1] Washington’s War on Iran: The Importance of Defending Information Space https://www.youtube.com/watch?v=yiJm4zwZZHY

For the audience: I had never heard of Brian Berletic previously. In an attempt to understand what this person's undisclosed conflicts of interest were, I found numerous reports of him painting the Myanmar Junta in a positive light:

https://www.reddit.com/r/InformedTankie/comments/ufq4oq/a_co...

https://forsea.co/bangkok-based-conspiracy-blogger-brian-ber...

There's a certain event-horizon where bitterness taints / skews perspective enough that even what would otherwise be helpful insights becomes so costly to disentangle from grudge-extrapolation that it's not obvious if any of it ends up being worth the cost of entry. At least to me, this person's work seems well beyond that point.

Re: A decentralized peer-to-peer messaging application that operates over Bluetooth

#299

Post by rm30 »

MrDrDr wrote: post #255
rm30 wrote: post #244

Earlier quoted context omitted.

I’ve read all the posts and, as the 'old man of the village', I would suggest taking a look at FidoNet. It was running 40 years ago, for more than a decade, before the internet was available to the average person. Store-and-forward, hierarchical organization, scheduled transmissions, working over dial-up and radio links, everything is there. There is nothing new to invent, and it was far more reliable than the 10m re…

Thanks for posting - this is really interesting. An idea perhaps whose time may have come. Out of interest (no criticism implied) but do/have you use this tech? and if so what was your experience?

I never actually used Fidonet. I started on BBS systems just as the internet was becoming affordable, and I made the switch early.

However, I apply the concepts of FidoNet almost every day. I often design offline-first devices, where store-and-forward logic is a necessity, not an option. Many are deployed in remote areas where signals are never optimal, there a High-Gain Antenna is the only solution.

I also prioritize binary protocols over structured JSON; you have a much higher probability of delivering a few hundred bytes of binary data than a bloated text object when the link budget is tight. Finally, I never expect Wi-Fi to work beyond 5-10m when the router is placed inside the metal structure (that's why my skepticism about BT on cruise ship).

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