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Cellphones Crime Technology

GA Tech Students Use Cell Phone Pings To Find Missing Person (ajc.com) 127

McGruber writes: Georgia Authorities are giving kudos to technology – and the perseverance of Georgia Tech students – for the safe return of a fellow student who disappeared after a Friday night party. The missing student was found Monday morning along railroad tracks, in northeast Atlanta. He had been beaten, was unconscious and was taken to Grady Memorial Hospital. Georgia Tech Police Chief Robert Connolly said "The students rallied together and then they started searching. The students stayed out until midnight last night, putting out pamphlets and combing the area, anywhere they could possibly find [cell phone] pings along the route." The students "were not going to stop. They checked every hospital, every hotel, they checked everywhere. They didn't give up on their friend."
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GA Tech Students Use Cell Phone Pings To Find Missing Person

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  • SAR (Score:5, Interesting)

    by Citizen of Earth ( 569446 ) on Monday October 19, 2015 @05:57PM (#50761785)
    Search And Rescue teams should carry "Stingray" mobile cell towers with them to locate missing persons in the wilderness. Any phone in range would try to connect with them.
    • Re: (Score:3, Informative)

      by Anonymous Coward

      Search And Rescue teams should carry "Stingray" mobile cell towers with them to locate missing persons in the wilderness. Any phone in range would try to connect with them.

      That's not what Stingrays are for.

    • Re:SAR (Score:5, Insightful)

      by barc0001 ( 173002 ) on Monday October 19, 2015 @08:36PM (#50762597)

      I had that idea years ago. They could mount one in a chopper and once they get a ping, crank down the range to quickly narrow the search. But of course we wouldn't want to use Stingrays for saving lives when they're much more useful for spying on everyone.

      • Re:SAR (Score:5, Insightful)

        by ShanghaiBill ( 739463 ) on Monday October 19, 2015 @08:46PM (#50762633)

        But of course we wouldn't want to use Stingrays for saving lives when they're much more useful for spying on everyone.

        Those two uses are not mutually exclusive. In fact, the former facilitates the latter. Law enforcement can justify the procurement and deployment of a Stingray for search and rescue, and then use it for spying on the boyfriend of their ex-wife when there is no SAR in progress. They could use the same argument to justify the drone it is mounted on.

        • by sjames ( 1099 )

          Nerf it. Remove the capability to relay calls to a legit phone network and have it "complete" all calls to a recording identifying the device and it's serial number, then to a handset connected to the box in case it's a 911 call.

      • Re:SAR (Score:5, Informative)

        by schnell ( 163007 ) <(me) (at) (schnell.net)> on Monday October 19, 2015 @11:05PM (#50763211) Homepage

        I had that idea years ago. They could mount one in a chopper and once they get a ping, crank down the range to quickly narrow the search.

        That's almost entirely unnecessary (and this article is almost total crap).

        If your cellphone is turned on (and not out of battery), and within range of a cell tower, your provider will know about it. Your phone "checks in" every so often to make sure calls to it are being routed to the correct tower. Police can lawfully, with a warrant, subpoena this information from your provider, no Stingray required. If for some reason your phone was on but outside the range of any cell towers, your idea might make some sense. But in that case it wouldn't need to be a Stingray per se; a portable cell tower (like providers deploy for disasters/emergencies) would do the trick just the same.

        Oh, and while I'm at it, college students have no way to access the information of cell phones pinging providers' cell towers. The closest you could reasonably get is if they have each others' iPhone "Find My Friends" or Android equivalent, which would actually pull a full GPS location off the phone. But that is available to every jackass in the world you choose to share your location with, no engineering prowess or ingenuity involved. And it has nothing to do with "tower pings."

        TL/DR; Stingrays not necessary. College students have no legal access to the cellphone tower "ping" information and shouldn't. Slashdot editors should consider actually, you know, editing story submissions into being cogent rather than clickbait.

        • A lot of the most dangerous and time-sensitive search and rescue missions are for people outside tower range, hence his argument. Think national parks, hiking in the rockies and alaska, and so on.

        • Police can lawfully, with a warrant, subpoena this information from your provider, no Stingray required.

          I am not sure that the process you describe would really work in an emergency. In the major metropolitan area that I live, it would take many days for the emergency services officials to get that info from the telco. I've been privvy to one request and the amount of paperwork and process that the telco requires is substantial. They don't make a distinction between a stolen car or a person bleeding to death somewhere. The request process is the same. Naturally, there are certain government agencies that

        • "If your cellphone is turned on (and not out of battery), and within range of a cell tower,"

          That's the key piece you're missing. With wilderness SAR the whole problem is they aren't in range of a cell tower.

        • Cell phone signals do not work well for narrowing down a cell phones location very well. The signal tends to be reflected around by obstacles in the path, so you get reflections and such. The cell tower can also serve an area as large as 50 km radius, which makes locating a person less than ideal.

          However, if you can get the position from the GPS over the data network, you can find where the person is within a few feet.

    • For sure! Being able to locate missing people (sorry, "persons") would be even better than if they could only locate their phones. ;)
    • The stingray like devices I have seen before don't have more than a 1k ft range, so using it for that purpose doesn't work very well. Cell towers can reach 50 km, but they use an enormous amount of power to get those ranges. A stingray is a portable device running off battery.

  • Or is it post the fucking article?
  • With an iPhone is battery would have been long dead over 2 days...
  • by Anonymous Coward

    Too bad the Georgia Authorities couldn't rally together, start searching and persevere until the student was found.

    • by Obfuscant ( 592200 ) on Monday October 19, 2015 @11:15PM (#50763255)
      To initiate a wide-spread search takes a lot of people -- more people than you want to have on your payroll all the time just in case they are needed.

      And initiating a full-scale search for a person who is of-age and not known to be in danger would create a lot of full-scale searches for people who just didn't want to be where they were. We had the owner of a local hot-dog shop just not show up for work one day around here. He was found a few hundred miles away just trying to not be involved with the hot-dog shop anymore. The owner of a car audio store did the same thing about a month prior.

      That's why missing person reports don't automatically trigger an all-out search. Not for a college student who just didn't come home. Now, one that is kidnapped from the street, or a dementia patient, or someone who is reported missing in a wilderness area, yes. But a college student who could have easily decided to shack up with someone for the weekend? If you burn out your search volunteers looking for people who just didn't want to be where they were anymore, you'll not have them available when there is someone who really does need to be found.

      • How quickly would they have found him had they just pinged his cell phone? This is something that is supposed to be available to law enforcement.

        It may have had more to do with that they can't immediately investigate as he is an adult.

        • How quickly would they have found him had they just pinged his cell phone?

          Sigh. They don't ping the phone, the phone pings the towers and the cell company provides the data about that to public safety. And they did that. It doesn't give an exact location, and it doesn't say that the person holding the phone is actually missing in a way that required a full-scale search to be started.

          It may have had more to do with that they can't immediately investigate as he is an adult.

          And not obviously in need of being found.

  • by YesIAmAScript ( 886271 ) on Monday October 19, 2015 @08:47PM (#50762635)

    And how does it reveal your location?

    Does this mean some kind of peer-to-peer WiFi or Bluetooth? I don't understand.

    If it's cellular, then the phone is either reachable or it isn't, that doesn't change based upon how near you are to the other phone.

    Are they saying they just used a built-in location service to find it?

    • by lakeland ( 218447 ) <lakeland@acm.org> on Monday October 19, 2015 @09:04PM (#50762691) Homepage

      Pinging a cellphone means setting up a portable cellphone tower. All cellphones within range will report their existence to you, which you can then cross reference against your missing person's IMEI number...Through triangulation/multiple different towers you can work out the location quite accurately.

      Of course this is not generally available to the public. For a start you need to have a portable tower (or borrow a few from a local telco) and secondly you'll need to cross-reference his phone number to look up his IMEI.

      I'm curious how a bunch of students were able to get past the two restrictions - I can imagine a uni having some portable towers lying around for research purposes, but how would they have found out his IMEI number?

      • by cdrudge ( 68377 )

        I'm curious how a bunch of students were able to get past the two restrictions - I can imagine a uni having some portable towers lying around for research purposes, but how would they have found out his IMEI number?

        Cell phone company? Service contract? Product's packaging? There are a bunch of plausible possibilities.

        • Other than digging up a command to get the imei from my own phone directly, I wouldn't know how to get it.

          Packing? Long gone.

          Phone bill? Not written on it (and other people may have a hard time finding my phone bills - they'd have to start digging through my stuff).

          Mobile phone company? Well, I hope they don't provide any information about me and my contract over the phone to just anyone that asks. Not sure if they have my IMEI registered in the first place.

          • they'd have to start digging through my stuff

            Which, as I understand things, is a deal breaker with most national telcos.

            Not sure if they have my IMEI registered in the first place.

            Of course not... then they could pwn you and your freedom loving cellphone.

            • they'd have to start digging through my stuff

              Which, as I understand things, is a deal breaker with most national telcos.

              My telco of course issues my bill. No IMEI written on it. It'll also differ by which nationality those national telcos have - and I don't know about yours.

              Not sure if they have my IMEI registered in the first place.

              Of course not... then they could pwn you and your freedom loving cellphone.

              Dunno what you're trying to say here. My phone is not sold by my service provider, so other than reading my IMEI after I put the sim in and connect, they don't know this.

              • "The IMEI number is used by a GSM network to identify valid devices and therefore can be used for stopping a stolen phone from accessing that network. For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to "blacklist" the phone using its IMEI number. This renders the phone useless on that network and sometimes other networks too, whether or not the phone's SIM is changed."

                It seems unlikely a unique identifier is unavailable to the powers that be.

                • That doesn't mean they'll give out the IMEI to anyone that calls. The above implies that it's the phone owner asking to have a specific IMEI blocked - not sure how useful it is as the thief could just pop in a SIM belonging to another network - while in this case the search team would at first have to be able to get the IMEI number somehow.

                  • That doesn't mean they'll give out the IMEI to anyone that calls.

                    His parents are likely the account holder.

          • Mobile phone company? Well, I hope they don't provide any information about me and my contract over the phone to just anyone that asks. Not sure if they have my IMEI registered in the first place.

            Being a college student, it's likely that his parents are the account holder.

      • He was a missing person, and the police were involved.

      • by Wycliffe ( 116160 ) on Monday October 19, 2015 @10:01PM (#50762911) Homepage

        I'm curious how a bunch of students were able to get past the two restrictions - I can imagine a uni having some portable towers lying around for research purposes, but how would they have found out his IMEI number?

        From the article (hiding in the header), I don't think that they did. It sounds like the police gave the students the last known cell phone towers and they canvased the area on foot around those towers.

      • by Obfuscant ( 592200 ) on Monday October 19, 2015 @10:48PM (#50763113)

        Pinging a cellphone means setting up a portable cellphone tower.

        No, pinging a cellphone doesn't mean setting up a portable cellphone tower. "Pinging" is the what the cellphone companies call the process a cellphone goes through trying to register with any available cellphone tower (almost always fixed). It's an analogy for the "ping" command in unix.

        There are established procedures for public safety agencies to request and obtain the cellphone data. All it takes is a signed affidavit attesting that the data is necessary for safety of life -- which this clearly was. One of the first questions in the lost person interview is "does he own a cellphone and what's the number?"

        With one cell tower hearing the ping, you can get a direction (from the phased array antennas they use on a tower) and an approximate distance (from the signal strength.) Both are recorded for every ping.

        From two or more towers you can use either triangulation (multiple bearings to the same ping) or time-of-arrival differences to measure the relative distances. (The latter is the basis for GPS.)

        I've been involved with searches where the ping has resulted in locating the subject within a few hundred yards. One such search didn't result in a find right away because the subjects were trying to hide and heard the aircraft that was looking for them. They came out a few days later when they got hungry.

        • No, pinging a cellphone doesn't mean setting up a portable cellphone tower. "Pinging" is the what the cellphone companies call the process a cellphone goes through trying to register with any available cellphone tower (almost always fixed). It's an analogy for the "ping" command in unix.

          And the technical term for how that is handled is "mobility management" [wikipedia.org], if anybody wants to look up the procedures in painful detail. (But beware, telecoms standards are actually physically painful to read... You have been warned.)

          • (But beware, telecoms standards are actually physically painful to read... You have been warned.)

            I'm currently reading "From GSM to LTE" by Martin Sauter, and I can attest to the fact that you will die a horrible death from acronym overload if you try to memorize even any of the basic level stuff. IAM BSC MSC GMSC AMSC RMSC VMSC eMLPP APDU BCCH PCH LAC MSRN IMSI VLR TRAU A5/1 A5/2 A5/3 FR HR AAAAAAHHHHH!

            • Testify, brother! Testify!

              My favourite when I was in the business was the doozy in the 3G 3GPP 23.060 standard: "IPv6 support is mandatory, IPv4 support is optional. The preceding sentence is not to be interpreted such that an implementation providing only IPv4 support is deemed non-compliant". (Or words to that effect.)

              Yes, I know the politics that went on behind closed doors to end up with such a wording but seriously, W.T.F?!

      • by PPH ( 736903 )

        Pinging a cellphone means setting up a portable cellphone tower.

        Nope. Many carriers can do this with their current equipment. It's a requirement of E911 [wikipedia.org] service. And it actually doesn't requite that a 911 call (or any call) be placed. I listen to the undercover cops on the scanner all the time and they can track a subject to within a few hundred feet in real time. "He's moving northbound now. Looks like he pulled into the McDonald's at Main Street." They can track them on city buses or walking, so its not a GPS tracker on the bumper.

      • by fche ( 36607 )

        "Pinging a cellphone means setting up a portable cellphone tower."

        The articles don't suggest anything like that was actually done here. It seems as though cell phone the victim was carrying was running a normal location-reporting service, and others (the cell phone owner?) happened to have permissions to that data.

      • by bkr1_2k ( 237627 )

        Assuming he's a friend of people who have access to the right tools in the first place then they probably already have his IMEI for "testing" or just messing with him when he's within range. We use our own phones all the time to test these devices. I have a list of mine and probably 15 of my coworkers IMEIs on a computer (not accessible from the internet) that most of us have access to use.

  • Method? (Score:4, Interesting)

    by manu0601 ( 2221348 ) on Monday October 19, 2015 @08:47PM (#50762643)
    How do you ping a phone? Was it through some app, or at the network layer?
  • by Anonymous Coward

    At least according to the posts on Mom's Facebook page [facebook.com] that are linked from the AJC article.

    Very little mention of the other students that actually did the work.

    Really lady?
    If your God was so fucking awesome, why did he let this guy get beat within an inch of his life and left to die?

    /posting anonymously because I think religious nuts are fucking crazy.

    • by Falos ( 2905315 )
      So you're both shoehorning, then.
    • "f your God was so fucking awesome, why did he let this guy get beat within an inch of his life and left to die?"

      Because even He has no sympathy for a white guy who leaves a formal and then, all dressed up, takes the subway home, in Atlanta. That's hanging a Beat Me And Leave Me For Dead sign on his back.

  • And with this submission, we start a new chapter in the history of /.

    Reading the article has long been optional and even disparaged, but now not reading the article is made mandatory by not even linking it in the first place, saving the precious feels of those who might have been the least bit guilty about rushing in to post without a clue.

    • If you click the (ajc.com) link right next to the title, you'll find yourself looking at the article, as if by magic!

      • by Mal-2 ( 675116 )

        If you click the (ajc.com) link right next to the title, you'll find yourself looking at the article, as if by magic!

        Magic indeed. I suppose this is the fault of the style sheet designer rather than the submitter or editor, but (ajc.com) is not underlined, is not a button, and is not part of a menu, so it never occurred to me that it was a link.

        • Re: (Score:2, Funny)

          by Anonymous Coward

          (ajc.com) is not underlined, is not a button, and is not part of a menu, so it never occurred to me that it was a link.

          UX Designer: "Nailed it!"

        • When you hover your mouse over it, an underline appears, revealing it's a link. I was also at first wondering what those domain names are doing next to the headline. The UI designer really seems to go out of their way to hide the fact this is a link, and they seem to even try to hide the existence of the link by making it green on green.

  • Cell Phone Pings (Score:5, Insightful)

    by YrWrstNtmr ( 564987 ) on Monday October 19, 2015 @09:21PM (#50762775)
    The actual article, once you freaking find it, has a one liner about "Cellphone records showed he was possibly in the area of DeKalb Avenue a couple of hours later." After that, it was just people walking around searching.

    How the hell is this 'cell phone pings'? I was expecting some uber geeky geolocation doodad written in an overnight Cheeto induced haze. (no, not THAT "uber")
    What, his phone did the auto check-in thing via some standard 'app'?
    • Thanks. I did manage to find and read TFA, reading it quickly, hoping to find more info on how they tracked down the phone exactly. Missed this little bit.

  • I thought all cellphones had GPS?
    • Re:What about GPS? (Score:4, Informative)

      by wvmarle ( 1070040 ) on Monday October 19, 2015 @09:47PM (#50762867)

      GPS is passive. It only receives, doesn't send information.

      The only way to get a GPS location from a phone is if the phone has the GPS function switched on, and then starts to send a GPS reading out through another channel - e.g. a WiFi or mobile data connection. In general this requires you to have an app running sending out your GPS coordinates to some server that records this info. Most phones don't have this function due to privacy concerns, and if they do, such records are (or at least, should) not be available to the general public to query.

      • In general this requires you to have an app running sending out your GPS coordinates to some server that records this info.

        Or dial 911. The E911 (enhanced) system includes GPS position data for incoming calls, including wired and cell. This system was put in place specifically to deal with people who call 911 and then don't know where they are so they can't tell the 911 op where to send help.

        This is why you are supposed to register an address with your VoIP cell service, so when you call 911 not only will the call be routed to the correct Public Safety Answering Point (PSAP) but so help can be sent if you are unable to tell t

        • The only way to get a GPS location from a phone is if the phone has the GPS function switched on,

          The consumer-available GPS function does not need to be "on" for E911 to get that data.

          Interesting, as Android at least does not allow apps to switch on the GPS receiver - it can only send users to the settings, asking the user to switch it on. So either it's a backdoor, or (more likely) they get the location not from GPS, but from the mobile network which can triangulate a phone's location - that failing, as you need to see at least three towers for that, the network can narrow down the search area considerably.

          • by Anonymous Coward

            The phone recognises 911 being called and turns on positioning as needed. It's a requirement of E911, and baked into the firmware that it can do that.

            I wish morons with no knowledge wouldn't make stuff up and post crap.

      • Most phones don't have this function due to privacy concerns, and if they do, such records are (or at least, should) not be available to the general public to query.

        Actually, most Android phones do have this feature enabled by default. If you know somebody's Gmail credentials (I've guessed dozens of them myself for people that I know), then you can get the current location of the device associated with that account, and their entire past history!

        If you have an Android phone, then you really need to look at this: https://support.google.com/gmm... [google.com]

      • by bkr1_2k ( 237627 )

        Plenty of cell phones report their GPS back to the system and to stupid apps people use to track every move and report it to whatever Twitter/Facebook/narcissistappoftheday they happen to use.

        Technically it isn't the GPS "reporting" it but that's not really the point. There are plenty of ways to track the position of a cell phone.

  • Hmmm (Score:5, Interesting)

    by John Jorsett ( 171560 ) on Monday October 19, 2015 @09:48PM (#50762871)
    There's some significant holes in this story. According to the ajc.com article, he had last been seen 11pm Friday. Friends started looking for him "last night," presumably Sunday based on the article's date of Monday, Oct 19. That means he would have been lying unconscious for up to two days, yet later in the article we read, 'Atlanta police Lt. Charles Hampton described Hubert’s injuries as minor, adding that he was “not sure where those injuries came from.”' Also, what are these pings they're talking about? Pings like when the cops have the phone company tell them which towers his phone is hitting? Were the cops relaying that info to student searchers instead of searching themselves? It sounds like something else: "The students stayed out until midnight last night, putting out pamphlets and combing the area, anywhere they could possibly find [cell phone] pings along the route.” How do civilian student searchers "find pings"? I wish journalism wasn't such a realm of technical illiterates.
  • by Bartles ( 1198017 ) on Monday October 19, 2015 @10:20PM (#50762999)
    ...no foul play was suspected.
  • Pings? (Score:4, Funny)

    by Gibgezr ( 2025238 ) on Monday October 19, 2015 @11:22PM (#50763273)

    Ahhh, they probably wrote a VB app to "ping" his phone...I wish we had some video footage showing the size 400 font and single-button UI in action though.

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