Locating a disconnected phone: a myth?

Reading the recently published topic “How Facebook defended Tunisian accounts” , at the very end of the article drew attention to the case of Minsk. Reading the comments on the link , I came across the statement that you can listen to the disconnected phone and various tips, including taking out the battery.

Regarding the tracking of the included device, - there is no doubt, - there is LBS , and it should not be confused with A-GPS . And in 2009, MTS itself announced the location service.


* A-GPS feature
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Regarding this technology, there are no complaints, although it is necessary to take into account some features of LBS (publication on Mobile Review ).


* general LBS working principle


* factor affecting position accuracy

While searching and collecting information about tracking a disabled mobile, I found an article on the Komsomolskaya Pravda website (the article is dated 2006).

Also interesting is the fact that on a number of sites this article is republished, but the text itself is somewhat different, namely, the article on the CP has reduced information on wiretapping and location detection. In support of the source 1 and source 2 refer to the source in KP, which suggests the idea of ​​changing the text of the article.

The fact of wiretapping a disconnected phone is also listed in the Ferra news archive .

A couple of years ago, the operators' answering machines (at least with us) gave a different answer when the phone was turned off (“the subscriber is unavailable”) and the phone is offline (“the subscriber is out of coverage ...”), but now the answer is the same and the experiment doesn't appear possible.

It will be interesting to check whether the battery will sit down faster while in the switched off phone. However, the best test would be to use special equipment to determine the "signs of life" of the apparatus.

Therefore, the question to the community, who has some opinion about the possibility of interception and calculation of the location of the disconnected phone?

UPD 1. Partially the question was raised on a habre in the topic “Anonymity in GSM networks” .

UPD 2. The GSM standard provides that the device (in the on mode) periodically gives / receives a signal, since It is necessary to switch between cells.

UPD 3. The battery physically powers the circuit. And the “power” button is not the first element in this chain, otherwise you wouldn’t be shown the mode selection (on modern models). This is far from a “hard” power-off with the physical opening of contacts, but already in essence a “soft” power-off.

UPD 4. A modern telephone (as a rule) is a powerful receiving and transmitting device, and is able to work even inside pots, refrigerators, etc.

UPD 5. At Mail.ru, the question was raised and the opinion was common ( Example 1 , Example 2 ). There is no unambiguous exact answer.

UPD 6. On Antichatat, people also write that the phone " pings ", even when it is turned off.

UPD 7. I recommend reading the information about the " Open Oscillating Circuit ". In theory , the device can be in the “listening” mode of the frequency, and when receiving a given command, issue a response of low power.

UPD 8. As already mentioned in the comments, a number of phones are able to turn on themselves, at the command of an alarm clock set by software. And from this it follows that the layout and power management in the device is not so simply arranged.

UPD 9. The technical aspect of the implementation opportunity has been partially raised on the Mobile-Review resource.

UPD 10. The farther into the forest - the more firewood. On the weapons portal, the issue of finding the switched off tube is also open.

UPD 11. As follows from the many comments, the modified firmware allows you to do this. However, we are interested in the phone "from the store." Hacking the server with the firmware and pouring the hacked one is excluded, because this is exactly paranoia.

UPD 12. RFID : unique identification without batteries in a miniature version (but only for a short distance).

PS For those who put a minus. For you personally, I respect your point of view, but I absolutely do not care about the ranking of the topic and whether it will come to the main or not. The question on the Internet is open, and there is no definite answer to it. Therefore, a topic was created on a resource where there are technically literate people who are able to express their opinions.

We are not talking now about whether this is done in practice by special bodies, etc., we are now talking about the technical possibility of doing this (direction finding of the device and periodic sending of ping).