Smart phone detection using Node-RED

Can we detect a smart phone inside a room using NodeRED with a phone having WI-Fi turned OFF.

You might be able to do it with bluetooth, try searching for presence detection for some examples

@ukmoose What about the bluetooth even turned off ?

@ukmoose I mean the phone just has its data ON and i have to detect it. Is there chance of getting the MAC data or something else ?

This now sounds like a task you’ve been set.
Is this homework / coursework? If not just turn wi-fi and bluetooth on.

@ukmoose Haha, No just to detect people with unregistered MAC id or any details.

Do you mean the phone has it mobile data connection on (so it is accessing the internet via the mobile phone system) but does not have wifi or bluetooth switched on? Forget about node-red for the moment and ask yourself is there any way to detect that the phone is present? The only way I can think of is to run an app in the phone that sends its location to a server (google location tracking for example) and then interrogate the server to find where the phone is. That won't give you room level location though. Alternatively you could ring the phone's number and listen for it ringing. You would have to give each phone a unique ring tone to check it is not just a coincidental ringing that you are picking up. The down side of this technique is that it might be a bit annoying for the phone owner and other people within hearing range of the phone, with it ringing every few minutes to check where it is. It would be a very interesting node-red project however.

@Colin You have given a very good advice. i appreciate for the time you took to write. But what about the phone is some else's and you have to detect its presence.

So now you are trying to spy on someone else's phone that is not in any way connected to devices under your control? I sincerely hope that is not possible without the resources of a government surveillance system.

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@Colin Is there any signal or the RSSI of the phone can be detected with its data on ? or something it radiates ?

As far as I know phones transmit over the following systems

  1. Cellphone: this is the network that mobile data and voice phone signals are sent over. Unless you have a cellphone signal detector in the room and the knowledge to hack into the cellphone signals then you won't be able to use that. Possible hardware and s/w to do that can be purchased but I don't know anything about it.
  2. Wifi: You have said that is turned off.
  3. Bluetooth: You have said that is turned off.
  4. Audio: As I have suggested you could use ring tones or something similar to do this but there are downsides.
  5. Light: Cameras are able to transmit light via the screen and the camera light, but I can't think of a way of using that, and it would only work if the phone was not hidden in a bag or pocket.

How about this for another possibility, use cameras and face recognition and use the presence of the person to imply the presence of that person's phone? That might work. Face recognition s/w is available for the Raspberry Pi I think so you could have one in each room along with cameras trained on the entrances and exits to each room and use that to keep track of which room a person is in, then you would know where the phone was. On second thoughts that wouldn't work if the owner left the phone in a different room.

@Colin That's right. As per the restriction i mentioned, there is no option left than making a hardware for detecting the waves. I was thinking of getting any data packets that is always radiating rom the phone (The intruder) in the room.That option also i think seems impossible. btw thanks colin for taking so much time to advise me and clearing my doubts. Camera is not a feasible option for the my case.

This would almost certainly be illegal in most countries unless you are doing it with the explicit consent of the people.

You would have to have your own network cell.

You could possibly detect the emitted radiation using a cheap USB SDR tuned to the appropriate frequency. However they probably can only detect phones that use the lower frequency bands (around 900MHz) - and ONLY when they transmit. If they are just on but not being used they will be in receive only mode most of the time so would not be transmitting.