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

On Wed, 29 Aug 2007 07:45:05 -0400, Elmo wrote:

Ann wrote:
On Tue, 28 Aug 2007 13:50:56 -0400, Elmo wrote:

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".

Going back a bit, to what you mentioned about some towers being aimed
"down". I think that must be the case with the primary carrier here.
There is coverage in the valley, a mile away, but only up to about
1,700' on the hillsides. (Looking at the coverage map one can surmise
where the tower is and the hills aren't in shadow.)

I'd say the towers aren't so much as in a shadow as on the wrong side of
the "sun".

No, this is the side of the hill facing the tower.


.

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 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: "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. ...
    (misc.rural)
  • Trip Report for April 8th
    ... There were no shortage of shuttle busses for the new car rental ... blends into the white noise that I need to sleep. ... I woke up at 7 and made my usual visit to the Strat tower. ... While standing in front of the elevators, 2 totally smashed girls came ...
    (alt.vacation.las-vegas)