Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Is it possible to detect a phone radio and measure how far it is from the cell?

Status
Not open for further replies.

jfbaro

New Member
Hi,

First of all, I am a completly newbie regarding electronics.

Imagine I have a low range device which is able to detect the tries for connections from mobile phones (considering there is no cell tower in range).

Is it possible, somehow, to detect how far is the mobile phone (trying to connect) from my device (maybe only the antenna or something).

I am talking about 10 - 15 meters precision.

Sorry if my question does not make any sense. I would be happy to give any further detail you guys may need! :)

Regards
 
It makes sense, but just let me read back your question to you to make sure we (well, I) understand what you're after:

You want to know 1) about the presence of any active mobile phones within (x distance) of you, and 2) how far away those phones are from you, within 10-15m. Is that correct?
 
It is, indeed! We are software developers (jfbaro and rarduin) and would like to build a open source device to help rescuing people after disasters. We are still developing the idea, but I think it's feasible. Please, check the projects page: **broken link removed**

The problem here is that the victim could have wood, metal, concrete over he/she and that would difficult quite a bit the measuring. But if, after a signal being detect, we could say to the Emergency workers the device had detected someone in such a region (or less, if there is loads of obstables - wood, metal...) I think it would be still helpful for them. What are your thoughts about it?

P.S.: As you probably imagine, we are not trying to make any money of it, the main goals are: 1) Helping people; 2) Learn a bit about the subject.

Cheers
 
It is, indeed! We are working on a project for helping rescuing people (We presented it at Rhok 3). See the short description:

"We'llFindYou (Formerly Known as FindMe ;) ) is a portable device which can detect people (through their mobile phones) without needing any special app installed, just an ordinary GSM phone running (We are still analyzing WCDMA and others).The idea is to have a portable and cheap device (based on femtocell) which would be used to "detect" people (maybe unconscious) just after the disaster. That device could be sent to key people living in developing areas. They (probably volunteers) would walk in groups trying to detect mobile phones through mobile phone's keep alive signal. If the volunteer find someone but is not able to rescue the person right away he/she could keep walking in search of the next person. The device will store the GPS positions where it detected any keep alive signal so that when the emergency workers arrive they can collect that data from the devices and go for the rescue."

We need some way to detect how far the phone is from the device... for example, if the device range is short, say 15m, we could say the detected phone is, at maxium, 15m away from that point (considering there might be wood, concrete, metal... over the victim).

What do you think?

P.S.: Sorry for the late reply, I have replied about 30 minutes ago, but as the reply had a link it got into the moderator queue (I didn't know that).

Cheers
 
Last edited:
My first guess(tm)(R) is that you're going to need to use triangulation to determine distance, since as you say, signal strength is likely to be wildly variable because of blockages in the signal path. Any way you can make this work with two people working in a team? Plus I don't know how you'd tie them together; probably through another wireless connection of some kind.
 
Yes, people working in pairs would be the recommended pattern. What parts the device needs to work properly is all open in the air. We are trying to collect information and finding out what are the problems we need to invest more time into.

So, if we can have people walking in pairs and a way to communicate the two devices would such a device be feasible? One of the main goals of this project is to have a low cost, say, under 300 US dollars (the less the better), so that developing countries could buy them and send them over to the people in risk areas.

Thanks for all your help! :)
 
You would need devices that could work in pairs. Obviously the two receivers have to determine that they've picked up the same signal (based on frequency? other characteristics?), and communicate with each other.

Which is starting to seem like a fairly complex project. I think ultimately the hardware might not need to be very complicated: possibly a microprocessor-driven unit with a radio receiver for the scan, plus a wireless connection to the companion device. But the software would be the tough nut to crack here.

Challenging design project for hungry engineering grad students???
 
Thanks Carbonzit.

We are two experienced software developers (with no electrical background), so (hopefully) we could figure out the software part. The hard bit for us, is the one you have been explaining, the hardware parts. :)

Do you think we could find people here who would help us on the project, I mean, we are investing time on this, not aiming any profit (really!) as it is some project which would potentially help people after a disaster.

What do you think?
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top