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Comment by eyeareque | Hacker News Reader

This is great. I wonder if by making the stingray'd phones transmit at full power, it allows them to find the phone quicker/easier.

How quickly can someone create a phone widget that shows when your cell "tower" has asked your phone to transmit at full power?

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Pie in the sky idea: App that indexes cell towers to a central database. When a new tower goes up, it undergoes a confirmation process that verifies its presence for some given amount of time before adding it to the list of confirmed cell towers. The software would then give you the ability to choose to only engage with/respond to registered towers.

This would only work if a good amount of people adopted it (and various other contingencies were satisfied).

There are legitimate uses for temporary base stations - often at large sports events cellular providers will install portable temporary stations for example.

The phone could just notify you: "A temporary base station has been detected - do you want to allow this?"

How would it know that the base station was temporary?

This is somewhere between a rhetorical question and a real one, in that I don't know enough about low-level cell protocols to know if temporary base stations identify themselves in a way that is detectable compared to "permanent" ones, but I would assume they don't?

If there's no way to tell the difference between a temporary and permanent station such a notification would quickly become unbearable as it would pop up each time a new station is seen.

In Australia this information is freely available in public databases anyway. Obviously temporary towers might not be present in these records though.

Also in Australia most / ?all? state police detectives carry General Search warrants, which allow them to search your property and person without applying to a court on 'reasonable suspicion' -whatever that means. I'm not sure if they have to arrest you first, but that doesn't really matter.

A 'General Search warrant' is a thing that shouldn't even exist, let alone that police detectives should be walking around with them. This is wrong on so many levels.

Wow, why even bother with making them carry "General Search" warrants if they can basically do whatever they want anyways? In the U.S., our police can claim to smell marijuana during a traffic stop and use that as a reason to rip your car apart looking for it.

OpenSignal already has a database of towers, with their associated FCC ID info. It would be trivial to crowdsource rouge/out of place "towers".

The closest thing to this is an Android app called 'Antennas' which looks like it is no longer being developed.

https://play.google.com/store/apps/details?id=com.technolatr...

To reply to my own comment, I realized that this could potentially be done more simply by just attempting to place a dummy call to an un-indexed tower when encountered (my understanding is that a Stingray isn't actually capable of handling calls). If >99% of calls failed (basically 100% with room for error), the tower could be confirmed bad and blacklisted.

Transmitting at full power probably isn't that rare. It could mean you're far away from the tower you're talking to, and that could even happen if a tower nearby is overloaded and you've been handed off to a more distant one to balance the load. It could also be due to noise on the channel, being in a building that blocks the signal, etc.

Also, information from the baseband processor in your phone (the processor that handles the radio transceiver, and would know what power you were transmitting at) may not be easily available to the processor that runs the apps.

an attempt could probably be made to calculate the power usage assuming it is the main power consumer by subtracting other major users of power like CPU, screen brightness, wifi, etc.

actually, scratch that. most android phones have per-component power consumption readings, so while you couldn't get the actual tx power, you could just base it off of the baseband power usage.

Depending on what information is available, you might be able to get a good idea if it's fake or legit by looking at signal strength, jitter, latency when communicating with that tower.

If the phone is mostly stationary, then there could be a cause for concern on the phone's behalf.

http://en.wikipedia.org/wiki/Mobile_phone_charm

I think one of the ones that "flash and light up when the phone rings" would do the trick for you. At least that is urban legend among people who need that kind of warning as I understand it.

Edit: ThinkGeek sells one... http://www.thinkgeek.com/product/a150/

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