Thanks, John:

> When you say "which cell tower it's currently connected to",
> will these devices be actually connected (with a
> circuit-switched connection), attached with an active GPRS
> session, or in idle mode (camped on a cell but not interacting
> with it)?

We are interested in knowing which cell tower we are connected to, just
prior to initiation of the GPRS session. Connection will be telemetry data,
no voice. The mobile laptop with GPRS card will be camped on a cell site
but not interacting with it. Then our server will attempt to initiate a
connection to it. The GPRS network will find our laptop. Our laptop needs
to know at that time (or immediately before) which cell site it is connected
to so it can report that in its response back to the server. We prefer
connections to be TCP-IP rather than circuit-switched. Does all this sound
possible?

> Reading the cell ID should be straightforward in idle mode, but
> will be trickier if the laptop is talking to something else
> /through/ the card at the time. You may have to momentarily
> suspend that connection/session, in order to have a brief
> conversation with the card itself.

That should be fine. We only need to know the cell ID when in idle, waiting
for a request from our server. That's the ID we will report back through
our laptop application after the connection is made.

> Some networks in some parts of the world broadcast a textual
> cell name (a "cell broadcast" or "area info" message) as well
> as a unique numeric cell ID. With most modern GSM modem cards,
> reading both should be possible.

Can you refer me to a Website where this information is available? We'll
need to write the S/W to get the cell site ID from the card. We'll also
need to be able to do a lookup of the cell site ID to determine its physical
location.

> But good luck if you're looking for software "off-the-shelf" to
> do these things.


Many thanks,

Henry