Re: "Amendment would allow the CAFOs closer to some homes"

Ann wrote:
On Tue, 28 Aug 2007 08:03:01 -0400, Elmo wrote:

Ann wrote:
<SNIP>

Since the wireless carriers are only required to locate within 100
meters, the technology isn't as accurate as land line Caller-ID in high
population density areas. But for someone trapped in a car that's run
off the road or a farmer, hiker, hunter, etc having a heart attack in a
rural area, 100 meters is close.


Without having the phone receive GPS satellite signals so it can "know"
where it is and tell the nearest tower[1] when it asks, the ability to
locate a phone depends on the range of the cell tower. Most cell towers
have 3 antennae each of which handles 120 degrees of arc and out to the
range of the tower. In urban environments, the number of towers is
relatively higher and the antennae are configured to point more "down"
than "out". This prevents a tower from being overloaded. In more rural
areas, the range is often greater. So if the phone can't say "I'm at
GPS location gridX, gridY" the best the tower can do is to locate the
sector the particular antenna the signal is being handled by and say
"That phone is somewhere in this area."[2]


[1] Towers don't have to be on towers, many are on buildings. [2] I
learned all of this while on a jury where the location of the
defendant's cell phone over time was used to match up with other
evidence which indicated that the person who stole the car from location
A and abandoned the car at location B and the cell phone which was near
point A at the time the car was stolen was later at point B where the
car was recovered. By itself it wouldn't have been compelling evidence
but it supported other evidence.

Lesson being not to carry a cell phone with a GPS chip while committing a
crime? <g> That's interesting. From what (little) I did read about it,
the FCC keeps granting extensions for a number of cell carriers to meet
the 100 meter requirement.


This was pre-GPS cell-phones.

They had to get a techie-dude from the cell phone carrier to explain the records which showed a call from [defendant's phone number] to [unspecified person but I believe it would have been the accomplice who had been convicted separately] being transferred from cell-tower to cell-tower. They had a map of the coverage areas for the towers and each antenna sector so you could see the progress from the "scene of the crime" sector to the "recovery of the stolen vehicle" sector and how the freeway ran through ALL of those sectors. The point being that 100 meters can't be guaranteed if the cell tower sector covers a big area. In this case it was somewhere within a 120 degree arc of a circle with a radius of about a mile from the tower location.

The other thing that can affect the ability to locate non-GPS phones (like mine -- I have an old Garmin that tells ME where I am but doesn't let on to anyone else) is the overall coverage area. My carrier provides very good coverage maps. My house is rated "very good" but if I go out the door and slide down the bank to the creek level the rating falls to "marginal". The steep slide down to the creek puts that area in a "shadow". .

Relevant Pages

  • Re: "Amendment would allow the CAFOs closer to some homes"
    ... But for someone trapped in a car ... heart attack in a rural area, 100 meters is close. ... ability to locate a phone depends on the range of the cell tower. ... location A and abandoned the car at location B and the cell phone ...
    (misc.rural)
  • Re: "Amendment would allow the CAFOs closer to some homes"
    ... But for someone trapped in a car ... heart attack in a rural area, 100 meters is close. ... ability to locate a phone depends on the range of the cell tower. ... location A and abandoned the car at location B and the cell phone ...
    (misc.rural)
  • Re: "Amendment would allow the CAFOs closer to some homes"
    ... But for someone trapped in a car ... heart attack in a rural area, 100 meters is close. ... ability to locate a phone depends on the range of the cell tower. ... location A and abandoned the car at location B and the cell phone ...
    (misc.rural)
  • Re: "Amendment would allow the CAFOs closer to some homes"
    ... But for someone trapped in a car that's run ... rural area, 100 meters is close. ... locate a phone depends on the range of the cell tower. ... A and abandoned the car at location B and the cell phone which was near ...
    (misc.rural)
  • Re: Whats the longest youve smoked....
    ... > joint early, around 7:00 p.m., to find nary a parking spot to be found. ... > As I was locking the car, a black, 1960's era Cadillac with blacked-out ... > who completely agreed with me that my arresting officer was an asshole ... I, too, had my own cell until ...
    (alt.smokers.pipes)