# Detect a cellphone with in a range



## PVR (Nov 17, 2020)

Is there any technology to automatically detect a cell phone in a range of 3 to 5 M proximity


----------



## cwwozniak (Nov 29, 2005)

Hi, PVR and welcome to TSG.

Yes, there are commercial products available that will detect turned on cell phones within a small radius of the device. They are typically used in places like prisons where cell phones are not permitted. A Google search for *cell phone detector* will give a list of available products.

It is also possible to train some dogs to sniff out chemicals used in electronic devices including cell phones.


----------



## zx10guy (Mar 30, 2008)

What's the goal of this?

As Chuck mentioned, there are solutions for this depending on what you're trying to do. May retailers do this along with Casinos. The solutions I'm familiar with involve WiFi or Bluetooth. The assumption is that the phone will have either of these turned on. There are specific Bluetooth sensors that are deployed to facilitate IoT deployments. Depending on the WiFi access point, it'll either do WiFi or both. Layered onto these devices is specific software that uses triangulation methodologies to do a geo location of the device. The more of these infrastructure devices are in place in a given area, the more accurate the geo location.

A use case is with Casinos. They use the fingerprint of VIP customer's mobile devices to tailor the experience of said customer. When the customer enters the building, an alert is sent out where someone from the hospitality group will meet the customer at the location they entered. From there, they're given the red carpet treatment.

Retailers use this technology to gather information on what products you're browsing based on where you are in the store. Targeted coupons or ads can be sent down to the mobile device based on this.


----------



## PVR (Nov 17, 2020)

cwwozniak said:


> Hi, PVR and welcome to TSG.
> 
> Yes, there are commercial products available that will detect turned on cell phones within a small radius of the device. They are typically used in places like prisons where cell phones are not permitted. A Google search for *cell phone detector* will give a list of available products.
> 
> It is also possible to train some dogs to sniff out chemicals used in electronic devices including cell phones.


Thank you so very much chuck ..yes I did find similar product...


----------



## PVR (Nov 17, 2020)

zx10guy said:


> What's the goal of this?
> 
> As Chuck mentioned, there are solutions for this depending on what you're trying to do. May retailers do this along with Casinos. The solutions I'm familiar with involve WiFi or Bluetooth. The assumption is that the phone will have either of these turned on. There are specific Bluetooth sensors that are deployed to facilitate IoT deployments. Depending on the WiFi access point, it'll either do WiFi or both. Layered onto these devices is specific software that uses triangulation methodologies to do a geo location of the device. The more of these infrastructure devices are in place in a given area, the more accurate the geo location.
> 
> ...


Hey thanks for your response and appreciate it very much. Was quite well put I should say....


----------



## cwwozniak (Nov 29, 2005)

You're Welcome.


----------



## PVR (Nov 17, 2020)

PVR said:


> Hey thanks for your response and appreciate it very much. Was quite well put I should say....


Hi I was planning on developing an attendance system for school purely based on their carrying phone on the person ..
Does it work to pick each unique phone identity in such a scenario...pl advice also any better way of communicating one on one to explain more in detail..I am kind of new here .
Thanks a lot in advance


----------



## cwwozniak (Nov 29, 2005)

I believe the types of devices I previously mentioned only detect the presence of a device operating on cell phone frequencies but do not attempt to identify a unique device. Reading and deciphering the data communications between a phone and a cell tower to identify a unique cell phone may be very difficult if not impossible or illegal.

You may be better off tracking phones that have WiFi enabled and looking for an access point. A WiFi-based detection device would be able to get the unique MAC address of each device looking for a WiFi connection. This is how some department stores track customers in their stores. The tracking is anonymous unless the customer registers their phone's MAC address to match it to their name and other personally identifying information. This could be done as part of the user installing the store's shopping app on their phone.

For school attendance purposes you might need to have the students install a custom app on their phone that not only allows the school to know they (or at least their phone) are in the building, but also allows the student to know that their entry was acknowledged. This could prevent issues with students entering the building with their phone's WiFi turned off for any reason and being incorrectly marked as being absent.

A Google search for *smartphone school attendance* should give you links to articles and scholarly papers on the subject.


----------



## PVR (Nov 17, 2020)

cwwozniak said:


> I believe the types of devices I previously mentioned only detect the presence of a device operating on cell phone frequencies but do not attempt to identify a unique device. Reading and deciphering the data communications between a phone and a cell tower to identify a unique cell phone may be very difficult if not impossible or illegal.
> 
> You may be better off tracking phones that have WiFi enabled and looking for an access point. A WiFi-based detection device would be able to get the unique MAC address of each device looking for a WiFi connection. This is how some department stores track customers in their stores. The tracking is anonymous unless the customer registers their phone's MAC address to match it to their name and other personally identifying information. This could be done as part of the user installing the store's shopping app on their phone.
> 
> ...


Many thanks and highly appreciate the time taken in penning down such detailed information....as I am mechanical engineer i am no good on lot of things related to electronics or communications as such was may be requesting trivial things ...but I am so glad I am being answered by kind gentlemen like your self ..thanks once again and have a very nice day ahead


----------



## cwwozniak (Nov 29, 2005)

You are most welcome.


----------



## Couriant (Mar 26, 2002)

Hello! 

I work for a university and we did have something like this as a test for one of the classes. I don't remember the name off hand but it's a system that you install the scanner/receiver in the room and the students downloads an app that will interface with the receiver I believe. Let me see if I still have those emails.


----------



## Couriant (Mar 26, 2002)

https://fletchapp.com/ - This is what the department used for the test. As far as I know, the test went well, but I don't know if it would be implemented.


----------



## cwwozniak (Nov 29, 2005)

From what I can find online, the Fletch system uses an installed app on the student's smartphone that uses Bluetooth to signal a hardware beacon device in each classroom.


----------



## Couriant (Mar 26, 2002)

cwwozniak said:


> From what I can find online, the Fletch system uses an installed app on the student's smartphone that uses Bluetooth to signal a hardware beacon device in each classroom.


Yeah, anything more than that may cause issues concerning privacy... like if it can track people to the bathroom via WiFi.

If the goal is for attendance, Fletch should be sufficient.


----------



## PVR (Nov 17, 2020)

Couriant said:


> Yeah, anything more than that may cause issues concerning privacy... like if it can track people to the bathroom via WiFi.
> 
> If the goal is for attendance, Fletch should be sufficient.


Thank you all for your valuable guidance and support . Have a good day


----------

