04-23-16 02:53 PM
33 12
  1. DueNorthBB's Avatar
    Just checked in with my Passport and the location works well.

    Blackberry Protect Not Being Updated By BB?-work.png

    Then suddenly it doesn't work anymore. It stopped working when I tried playing with the messaging and locking features.

    Blackberry Protect Not Being Updated By BB?-nowork.png

    Anti-Theft Protection became "unavailable" and location doesn't work. My GPS location became "stale".

    Just to make sure I am not out of wifi connection, I browsed a one the phone and even used the GPS.

    It isn't as reliable as the Apple Find-My-Phone app. It can work.. once in a while.
    04-23-16 01:18 AM
  2. Richard Buckley's Avatar
    Cell phone locations come from pinging a cell phone tower (3 or more) using triangulation, not from a satellite in the sky.
    Maybe your phone is out of range to pickup a signal? But since it was stolen, call your service provider and have it blacklisted.
    This is pure nonsense.

    04-23-16 06:03 AM
  3. danp2000's Avatar
    As a test, for myself, I just logged into BlackBerry Protect and the initial location was from yesterday. In less than 10 seconds it was updated to the current location.

    I like the fact that it initially only had my location from yesterday.

    Blackberry Passport.
    04-23-16 07:03 AM
  4. billbuck0's Avatar
    This is pure nonsense.

    04-23-16 10:08 AM
  5. Richard Buckley's Avatar
    Quoting from the article:
    However, as anyone with even a basic geometry education recognizes, which cell tower you're connected to does not give you a particularly exact location. It can be useful in putting someone in a specific (wide) area -- or, much more useful in detailing where someone is traveling over long distances as they repeatedly switch towers in a particular direction. But a single reading does not give you particularly exact location details. I had naturally assumed that most people understood this -- including law enforcement, lawyers, prosecutors and judges -- but it turns out they do not. A rather depressing story in The Economist notes that, thanks to this kind of ignorance (combined with bogus cop shows on TV that pretend cell site data is good for pinpointing locations), cell site location data is frequently used to convict innocent people. The story opens with a ridiculous example, in which a woman was pressured into a plea bargain based on totally false claims about tower location data: ...

    Obviously, things like GPS do allow for much more precise targeting of location
    And from your original post

    Cell phone locations come from pinging a cell phone tower (3 or more) using triangulation, not from a satellite in the sky.
    Triangulation is a process of using bearings to or from a number of known locations to determine an unknown location. Neither cell towers nor cell phones are capable of measuring the bearing to the other. They are capable of measuring received signal streangth, and the cell tower does know the power of the cell phone transmission because part of the management protocol is controlling the amount of power the cell phone uses. This leads to the tantalizing possability of determining a cell phone location by computing the distance it is from a number of cell towers based on the received signal streangth. Knowing the transmit power and the received streangth one can compute the pass loss. If you know the attenuation along the path you can compute the length of the path. The problem is that you can't know the attenuation without knowing the terrain and obstructions along the path. In practice this rarely results in very acurate locations.

    Your statement is pure nonsense.
    04-23-16 10:21 AM
  6. billbuck0's Avatar
    Cell Tower Triangulation – How it Works

    Last edited by billbuck0; 04-23-16 at 12:18 PM.
    04-23-16 12:07 PM
  7. tacit's Avatar
    For the first time in three years I put my phone down this morning and promptly forgot where I put it. Probably part of being 76 years old. I went to the computer used BlackBerry Protect. After a few seconds it said you left it in the bathroom you old fart...at least that's what I said when I heard the screeching sound.

    Posted from my BlackBerry Z10
    04-23-16 01:20 PM
  8. Richard Buckley's Avatar
    Cell Tower Triangulation – How it Works

    A little math comes in handy here. A millisecond difference in time of arrivale of a signal makes a very large difference in the distance, or put an other way it takes a very large difference in distance to make a one millisecond (one thousandth of a second) difference in the time of arrival. Light and radio signals travel at 300,000 killometers per second. So to create a difference of a millisecond would require moving a distance of 300 killometers, 186 statute miles if you use those units.

    Second, he is talking about how, in theory, a cell company might track your cell phone as you move about the network. We are talking about how the owner of a cellphone can find its location. So even if multilateration is be useded by the cell phone company to track your phone, it may not be available for an owner to find a lost phone.

    The article on multilateration is worth reading. Towards the bottom they get into computing the accuracy of fixes. They also cover the math needed to realy understand the topic and list applications. GPS is one. As is mobile phone tracking. That article is worth reading because it has a more realistic and informative presentation of the expected accuracy of positions generated. The cell tower based tracking accuracy you see on your phone won't come anywhere close to those numbers though, because the cellphonce company won't do the computation for their subscribes.

    I would also recommend the article on E911 which discusses the various techniques, documets the required accuracy (which is much lower for network based location becuase it does not perform as well as GPS) and how AT&T changed their minds about what system to use.
    04-23-16 02:53 PM
33 12

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