I'm an engineer working on E911 systems and I'd like to correct this whole
post. I've included some references so all your readers can peer review.
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#1 The chip does not function unless you either... Incorrect. The requirements
typically state for Public Safety and in support of local laws, the mobile
station (cell phone) has to handle all network requests for location.
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#2 Its not real GPS.
There are two separate systems that can be hybridized together.
First is the network based system described above that works great in urban
areas with lots of compatible cell towers. It is fast, but it can not get down
to 3 ft., maybe 100 m.
The second system is Mobile Station based (Cell phone) and it typically uses
GPS just like a Garmin. It works great in rural areas. It is not so great in
large cities as all the concrete, steel and coated glass both block and reflect
the GPS signals. A differential GPS system in time can achieve accuracies in
cm. However just like your Garmin, it can take a long while to search for satellites
and download the data from them.
The hybridized systems, where the network and the mobile work together, can
achieve the best of both accuracy/speed and urban/rural performance. The network
can tell the GPS on the mobile station approximate time, approximate position
(with xx km of the cellular tower), where the satellites are in the sky and
lots of other information that it would take your Garmin 20 minutes to get
from the satellites.Reference.
Section 10.10 GPS Assistance Data for more information. This document applies
to GSM and 3G/UMTS phones, but it is not atypical.
Also the new hybridized systems can combine the cell tower ranging with the
GPS satellite ranging to get a system that works where neither system alone
will.
#3 While it is possible...
Ah, no. The solution is Periodic measurements. in other words generating a
location every 5 minutes would not affect battery life much. It is used to
track commercial delivery personnel all the time.
#4 Yes there really is....
Again no. This is internet Fear, Uncertainty, and Doubt (FUD). The FCC requirement
is that x% of mobile stations can be located to certain accuracy. GPS is not
a requirement.
Reference.
#5 There is also the secondary issue.
The analog is not illegal, yet. It is just not cost effective for the bandwidth
reasons. Second for some networks that depend on GPS in the mobile station
(typically CDMA), the old phones stand in the way of meeting the FCC requirement.
#6 Analog shutoff.
I do not have any information on this.
#7 Cell phones use lots of electrical power...
Motorola Razor talk time 200-430 minutes. Standby 180-290 hours. Reference [JWR
Adds: I believe that the writer was referring to cell phone cell tower
facilities rather than hand-held cell phones themselves.]
As to charging more during blackouts, any company that did this would invite
a class action lawsuit for breach of contract and endangering the public.
OBTW, one other bit of FUD that I'd like to comment on:
Yes, off does not mean off in regards to modern electronic devices including
cellular phones. While "off" they may need to support an alarm clock,
calendar alerts, monitor battery charging, alert for low battery and do a lot
of other things. However, removing all the power sources kills anything! If
your phone continues to run without a charger or batteries, I think you could
name your price to sell it to any of the big cell phone companies. - Raven
Jim,
I have personally been present, when a 'Federal investigator' ordered a cell
phone security manager (what the heck that is I don't know) to 'turn on' a
particular
Electronic Serial Number (ESN).
It was my understanding that the phone had to be 'on' in the first place. It
was explained to me that there was a dual mode capability. One was the retransmission
of GPS positioning data and the second triangulation.
We found the 'bad guy' we were looking for for a covert surveillance regarding
a narcotics investigation.
He wasn't in a call - it was a pretty weird moment for me to see this happen,
and it was about four years ago. I can only imagine the capabilities built
into the system mandated by post-9/11 are more enhanced than then.
I trust the data given to me by the writer about GPS positioning as he understood
it. I saw different. The federal investigator was pretty closed mouth about
it, and the black box he used that (I suppose) received the data was no larger
than a lunchbox. Steered us right in.
I've long ago given up on trying to maintain much privacy in my electronic
life. I really don't have much to hide, but if I did - electronics wouldn't
have any place in my home. - Jimsee
