Suspicious tower sniffing

Discussion in 'Wireless Internet' started by miso, Nov 19, 2014.

  1. miso

    miso Guest

    I can neither confirm nor deny that I monitored analog cellular, but some
    calls didn't hop all the much. ;-) Nor can I confirm or deny I heard one of
    those phone sex service calls, but the conversation lasted long enough for
    the task to be completed. Um, allegedly. If it ever happened.

    Is there a statute of limitation on this stuff?
    miso, Nov 24, 2014
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  2. The timing varied. As I vaguely recall, 30 seconds per channel was
    about the maximum. Since you've effectively pleaded the 5th
    amendment, please consider yourself guilty of something. Note that
    the constitution entitles you to a speedy trial. In this case, the
    trial was conducted so fast, that you may not have noticed.
    "Statutes of Limitation in Federal Criminal Cases: An Overview"
    Prosecution is allowed for only as long as the wrong political party
    is in power. Since monitoring political figures might be construed as
    something that might be done by a terrorist, there is no expiration
    date as acts of terrorism are not protected by statutory limitations.
    Jeff Liebermann, Nov 24, 2014
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  3. miso

    Char Jackson Guest

    Around 1995 or so, an attorney friend pointed out that it wasn't illegal to
    listen in on cellular calls, baby monitors, cordless phones, etc. The
    illegal part was doing something with what you happened to hear.
    N/A if it wasn't illegal in the first place.
    Char Jackson, Nov 24, 2014
  4. miso

    Char Jackson Guest

    I lived in 3 states between 1991 and 1997, and in all 3 areas I was able to
    monitor AMPS calls in their entirety. Frequency hopping apparently arrived
    (in those areas anyway) sometime later, and then the death of analog after
    It used to be easy, but see below.
    But was the BS audio repeated on the handset channel, the reverse of what
    you say above? The reason I ask is that as I scanned through the 800MHz band
    back then, about half of the calls were full duplex, the other half of the
    calls were just one side of the conversation.
    Via the scanner, I didn't detect any delay/echo, which is not to say that
    the callers experienced the same.
    Char Jackson, Nov 24, 2014
  5. I was commuting between Santa Clara CA and Santa Cruz CA during that
    time and used Motorola bag phones and flip phones, all with AMPS. When
    I tried to listen with a scanner, it would hop roughly every 15
    seconds. I wasn't aware that there were AMPS systems without
    frequency hopping until you mentioned it now. I must confess that I
    didn't listen on cellular calls very often, and may not have noticed
    any changes in hopping.
    No. Both ends should have blocked repeated audio for the simple
    reason that it's neither necessary or desirable. There were some
    attempts to use AMPS for dispatch service, where it would be desirable
    to repeat the base station audio, but I never heard any of those. My
    guess(tm) is that if the echo canceller kicked in, you heard a one
    sided conversation. Turn off the echo canceller, and repeated audio
    might be possible. Still, the delays and echos are difficult to
    With digital modes, the delays are mostly due to the compression. The
    more compressed the audio, the longer the delay. However, AMPS did
    not use any audio compression. Most of the AMPS delays came from
    transmission delays and echos at the 2 wire to 4 wire transition
    points. In effect, they have the same problems as an old long
    distance phone line, with the same solutions being applied (frequency
    shifting to eliminate feedback, various echo cancellers, and a
    reliance on side tone over retransmitted audio. I don't know for sure
    as it's been far too long.
    Jeff Liebermann, Nov 24, 2014
  6. Cellular is blocked in most scanners by the ECPA enacted in 1986 well
    before the 1997 incident:
    You're correct that under the 3rd party FCC monitoring rules, you can
    listen, but not tell anyone.
    The illegal part was giving the recording to the politicians which
    constitutes disclosure. The Martins pleaded guilty and were fined
    $500 each.
    The NY Times should also have been fined for publishing a transcript
    of the conversation, but wasn't.
    Jeff Liebermann, Nov 24, 2014
  7. miso

    Bert Guest

    In Char Jackson

    My reading of 18USC2511 says that it's a crime to intentionally
    "intercept, any wire, oral, or electronic communication."

    Disclosing the content of such communication is also illegal.
    Bert, Nov 24, 2014
  8. miso

    Char Jackson Guest

    Cellular was indeed blocked in my Radio Shack PRO-2006, but removing the
    block involved snipping the lead on a single diode, if I remember correctly.
    It was beyond easy. I still have that scanner around here somewhere, but I
    haven't used it in years. These days, cellular has gone digital, a lot of
    police and fire have either gone digital and/or use frequency hopping, and
    CB scanning is useless with the little dipole antenna, etc. No one uses 900
    MHz phones anymore, so that's gone, as well.

    The last time I scanned CB, it turned out that I was within range of some
    woman with a base station who spent hours every day flirting with truckers.
    My (ex)wife used to listen in while I was at work. I guess it was her
    equivalent of soap operas. Speaking of duplex, we could hear the woman
    clearly, but we frequently couldn't hear the truck drivers. That would have
    required a better antenna.
    Char Jackson, Nov 24, 2014
  9. miso

    Char Jackson Guest

    That's interesting because it sort of indicates that all of the cell calls
    that I happened to monitor should have been half duplex, but that wasn't the
    case. I'd say roughly half carried both sides of the conversation.

    Back then, I was routinely traveling between specific locations in Missouri,
    Kansas, Nebraska, South Dakota, and Montana. I don't see any tech leaders in
    that list, so they may have been using systems that other areas would have
    considered obsolete?
    Char Jackson, Nov 24, 2014
  10. My memory from 20+ years ago isn't that great. I don't recall ever
    hearing a conversation that didn't hop, but I may have been mistaken.
    Not obsolete, but possibly with some features turned off. A failed
    frequency hop was a common cause of punching a hole in the
    conversation, or at worst dropping the call. If that happened, the
    handset would on the base station control channels, resychronize, and
    continue where it left off leaving about a 3 second gap in the
    conversation. Same thing for handoffs between cell sites, which
    usually involved a channel change. To avoid the problem entirely,
    some carriers may have turned off frequency hopping.

    Disclaimer: I'm guessing here.
    Jeff Liebermann, Nov 24, 2014
  11. miso

    dold Guest

    I don't know about crappy, but it is user generated.
    The cell tower nearest to my house is listed as being in the middle of a
    lake, because that is the aggregate of the reported location of all of the
    users hitting that tower ... around the lake.

    In a city, with lots of folks near the towers, the locations might be more
    What I found is towers, located by their owners in the database.
    I can see the towers at those locations on Google Maps, but not a clue who
    is on them. I think deliberately obscured through holding companies.
    I recall that tidbit from some locator that I used on my GSM-blackberry,
    but now that I have a CDMA Android phone, I still don't see it populated.
    dold, Nov 24, 2014
  12. miso

    dold Guest

    Could it have been home phones, and not cellular?
    I remember inadvertently listening to a phone call or two when I was trying
    to find good channels to listen to on my first scanner, purchased at
    Quement Electronics, in San Jose, CA.
    At the time, there probably weren't any cellular phones, and not that many
    wireless phones in the home.
    dold, Nov 24, 2014
  13. miso

    Char Jackson Guest

    No, I'm referring to the 800MHz band, analog cellular.

    At the time, there were cordless home phones at 900MHz and baby monitors at
    49MHz, (or was it 46MHz?), but you wouldn't confuse any of that stuff with
    Char Jackson, Nov 24, 2014
  14. I tested 3 apps, out of 4 that reputedly do fake cell tower tracking.

    1. wigle => reports the current cell tower (lots of numbers)
    2. imsi catcher detector => reports the current cell tower
    3. roaming info => I can't figure out what this one does
    4. gsmmap => only works on rooted Samsung devices

    None of them, to my knowledge, pop up a warning when/if the
    tower does something funky, and none leave a log that I know
    of for you to manually check.

    Given that you have to check in real time, they're not all
    that useful.

    But, it's a start.
    Andrew Beckett, Nov 25, 2014
  15. miso

    miso Guest

    One of the unpublished concerns I got from the tower dude was a scenario
    where monitoring analog cellular was done on the 15 freeway (AKA I-15)
    between LA and Las Vegas. The conversations were very stable in the desert
    due to flat terrain with widely spaced mountain top towers. Joe Gambler
    leaves LA for Vegas. Jane Gambler, ridding shotgun, takes out the analog
    cellular phone and reserves a room in Vegas. Credit card number goes out
    over the air, intercepted by a hacker.
    miso, Nov 25, 2014
  16. miso

    miso Guest

    I can't say that google database every gave me a correct location. Even in
    remote areas where the towers locations were in the FCC database since they
    had to license the backhaul.

    Possibly it doesn't suck everywhere.

    CDMA reporting is no longer done per another post.
    miso, Nov 25, 2014
  17. miso

    dold Guest

    The Google Database is acquired from users. It is not gleaned from

    It isn't the location of the tower, it is an aggregate of users' phones'
    GPS location when they are connected to a tower and use Google Location
    Services, just like the WiFi locations that Google collects.

    Out in the wilderness, the locations are going to be way off. I thought in
    the city they might be close.
    dold, Nov 26, 2014
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