I believe, in idle or 'standby' mode, cell phones periodically poll
the nearest cell station of their carrier system to establish location
and poll for messages.  How often does a phone in 'standby' mode poll
the cell network? (i.e. every 10 minutes, every hour etc)?  Is this
standard across carriers or vary for t-mobile gsm vs. bell atlantic
cdma etc.?  Is there any good technical documentation on this topic
available?

Hello Jheller-ga:

It was a very interesting research to do. I also consulted one of my
friends who is a consultant for Verzion Telecommunications.

Following is a summary of my findings followed by sources and other
links.

ANSWER:

Actually, Cell Phones do not poll the nearest cell station randomly
when on a ‘stand by’ mode but it is the nearest cell station (or base
station) that initiate the communication between them and your cell
phone to locate the exact location.

The time of the signal between the cell phone and the cell
station(base station) depends upon when you move from the area covered
by one cell station to another area covered by the another cell
station(base station). The whole process takes (400ms) and goes
unnoticed by the cell phone user.

As, Cell Phone coverage areas are divided into “cells” each of which
is serviced by the base station (tall towers you see when driving,If
you move out of the coverage of one base station, your phone switches
to the next strongest available base station. This means that the
system always knows your location relative to the nearest cell.

In simple words, when you move near the base station B and away from
the base station A, the base station B automatically detects that your
cell phone signal is getting stronger while the base station A
realizes that your cell phone signal is getting weaker. The base
station B and A interact and base station A gives the charge to base
station B. The process is known as ‘hand over’. At the same time the
base sation B sends a message to your cell phone verifying its new
position.

These base stations (in our case A & B) are in constant touch with
your cellular phone to determine your exact location.

The amount of time between this communications is usually 400ms (as
stated earlier) but can differ on the distance between base stations,
data channel, weather etc.

SUMMARY: It's not the cell phone but the base station that initiates
polling.

For more information, please consult the following resources:

AN EXCREPT FROM A SOURCE

“You repeat the old myth that cell-phones are constantly polling the
base-station while in standby-mode.
The fact is that they do not!
A cell-phone when on initial power up sends out a "here I am message"
in order
to locate and address the nearest base-station.
The next time it happens is when you loose contact by some reason,
e.g. moving
into a new cell, coming out from a tunnel after loss of reception etc.
If they where to poll the base-stations all the time, battery wouldn’t
last
very long.
It would also be logistically impossible.
Most base-stations handle a maximum of 32 mobiles at once.
The whole telephone-system (the copper one as well) is based on the
fact that
not everybody is calling at the same time”.
Source: http://groups.yahoo.com/group/bioelectromagnetics/message/985

OTHER SOURCES

Polling & Base Stations
Source: http://www.pcquest.com/content/depth/102101201.asp

Moving from Cell to Cell
http://electronics.howstuffworks.com/cell-phone2.htm

Another example of Moving from Cell to Cell
http://www.radio.gov.uk/topics/mpsafety/school-audit/mobilework.htm

Cell Phone Workings
Source: http://www.cellular.co.za/howagsm.htm

Cell Phone Location Tracking
http://www.techtv.com/screensavers/opinion/story/0,24330,3384074,00.html

Polling chat (see bottom/end of the chat)
http://www.wave-guide.org/archives/emf-l/Oct1998/(Burmaster-etc)-(A--Philips)-cell-phones-modus-operandi-(fwd).html

I hope this will help you. If you don’t feel satisfied, please clarify
before rating. I will be most obliged to help you.

Sincerely,
Leader-ga

---

Clarification of Answer by leader-ga on 19 May 2003 11:06 PDT

In my conclusion, I should state that It's not the cell phone but the
base station that initiates polling. The rate of this communication is
400ms (PC Quest) and that the rate might be effected by the distance
between base stations,data channel, weather etc(UK radio).

If the cell phone does not transmit a responce to the polling by the
tower, the tower obtains no information about the location, movement
or on/off status of that cell phone. 400 ms = 4/10 second, so it might
be noticable under some conditions. The transmit time of the responce
may be as short as 400 nano seconds = one second of transmitting per
million seconds of responding to polling from the towers. This would
run the battery down in months rather than hours. There is some other
drain on the battery while in standby and the responce transmission is
likely longer than 400 nano seconds. Likely the phone responds to the
polling from two or three different towers typically, and the "here I
am message" signal may be sent several times per minute by the phone
when the user is moving about at the edge of marginal reception from
any tower. The tower knows only approximently (not exact) your
location as the signal strength changes as the antenna tips and
rotates with body movements. That is how it seems to me.  Neil