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The article describes some circumstances under which a cell phone can be more precisely located. > Similarly, if you make an emergency 911 call, your company w

The article describes some circumstances under which a cell phone can be more precisely located. > Similarly, if you make an emergency 911 call, your company will use three towers to triangulate your location; if you’re using a smartphone, it will use G.P.S. to pinpoint where you are. If you’re the target of an ongoing investigation and law-enforcement agencies want to track you, they can ask a phone company to “ping” your phone in real time. The “ping” part caught my attention: this sounds like a method that actively queries the phone in a way that could be detected by the end user. Does anyone know if this is possible to detect? Would, for example, an Android phone allow a developer to write an app that could detect this and notify the user?

aisenik 12y ago
This is the sort of thing I'd expect them to implement in the black-box baseband processor. I doubt it'd be exposed to the host at all, though a little bit of sigint might do the trick.
13throwaway 12y ago
I'm really interested in a less-trackable cell phone, but until I read this article, It didn't seem possible. I am really hoping a fully open source phone comes to the market soon. It wouldn't have this ping "feature", it could connect to the second or third closest tower, and it could completely shut off cell when on wifi.
- gaius 12y ago
  Open source doesn't help, if you are using the hardware that has been certified to connect to the public network. It could have anything in it. You would need to start literally at the fab.
dobbsbob 12y ago
Phone baseband proprietary stack is bombarded with type0 SMS which will silently ack the msgs and thus 'ping' your location. There's probably carrier made tracking programs on SIMs too and/or your SIM can be modified by over the air update to install stealth tracking programs the host OS will never know about. FBI asked a carrier to do this once to track a fraud suspect http://www.wired.com/2013/04/verizon-rigmaiden-aircard/all/ http://www.wired.com/2013/04/verizon-rigmaiden-aircard/all/
chippy 12y ago
Related: There are APIs out there which enable you to write an app to allow your users to accept such pings. It costs quite a lot per ping, however, and if i recall may have to be allowed by SMS for each one by the user. It was seriously looked at before the iphone and pre ubiquitous GPS. The triangulation was done on (Vodafone?) proprietary boxes.

aisenik 12y ago

This is the sort of thing I'd expect them to implement in the black-box baseband processor. I doubt it'd be exposed to the host at all, though a little bit of sigint might do the trick.

13throwaway 12y ago

I'm really interested in a less-trackable cell phone, but until I read this article, It didn't seem possible. I am really hoping a fully open source phone comes to the market soon. It wouldn't have this ping "feature", it could connect to the second or third closest tower, and it could completely shut off cell when on wifi.

gaius 12y ago
Open source doesn't help, if you are using the hardware that has been certified to connect to the public network. It could have anything in it. You would need to start literally at the fab.

dobbsbob 12y ago

Phone baseband proprietary stack is bombarded with type0 SMS which will silently ack the msgs and thus 'ping' your location. There's probably carrier made tracking programs on SIMs too and/or your SIM can be modified by over the air update to install stealth tracking programs the host OS will never know about. FBI asked a carrier to do this once to track a fraud suspect http://www.wired.com/2013/04/verizon-rigmaiden-aircard/all/ http://www.wired.com/2013/04/verizon-rigmaiden-aircard/all/

chippy 12y ago

Related: There are APIs out there which enable you to write an app to allow your users to accept such pings. It costs quite a lot per ping, however, and if i recall may have to be allowed by SMS for each one by the user. It was seriously looked at before the iphone and pre ubiquitous GPS. The triangulation was done on (Vodafone?) proprietary boxes.