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Wireless M-BUS smart smoke detectors
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dan.vigour:
Hello,

I am in general incompetent in the field of radio communications and I have recently just started learning things, using SDR and reading a lot about the field of RF.

Some months ago, our building management company installed in every apartment Wireless M-BUS smart smoke detectors, which is required by law in Germany (the smoke detectors, not the wM-BUS). The devices are said to have 10mW transmitter (TDK5110) and work on 868MHz and ping every 30 seconds.

Some local dude, measured the RF power at 1 meter distance and it turned out to be 500uW/m^2.
He wrote a long article about the health risks. He seems to be a very competent engineer with lots of professional equipment. Of course being competent in a given engineering area does not exclude the probability of also being a nut job and a tin-foild head.

To me 500uW seems to be a negligible power, but I don’t have any real world experience in that area. I read that such power density can be easily achieved at your home by the TV stations, which blast at kWs of power at the tower. And probably I lived long enough with my WiFi router ...

I looked for information, but you stumble upon sites like ‘Bioinitiave’ and similar, which claim that legitimate medical studies are suggesting serious risks and we are being lied to (possibly by the government or by the lizard people) that RF is safe and even nano-watts will affect you, blah-balh. The general claim is that we really don't know the effect of RF on biological organisms as this is new and hard to research, intentionally underfunded  field.

I do not believe in 5G (or similar) conspiracies, however looking at the stupid thing in direct line of sight above my bed and knowing it pings every 30 seconds is getting on my nerves. Not to mention the installitation with my consent, required by law. Or the fact that it just does no need to ping that often, because it is not connected to a central hub that will call the fire brigade automatically. No, that's probably the original firmware used in hotels. I think that just the manufacturer decided to save penies on firmware changes. These devices are supposed to be checked once per year with walk-by or drive-by receiver, so why they ping every 30 seconds remains a mystery or incompetent engineering.

I like to hear people with real world experience, who actually work or worked in that area, because all this is getting on my nerves. I think I am losing it, not without the help fo the lock-down and having very restricted social life. My brain is in farting mode and I need some reality check.

On the other side, hacking wM-BUS protocol is fun as well. If anyone has the EN-13757 documentation, please let me know.
madires:
Just for comparison, DECT runs also with 10 mW (1880 - 1900 MHz).
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