They aren't encrypted per se (AFAIK), but they are encoded to conserve
bandwidth, which amounts to about the same thing: they are not
typically viewable as plain text. I work for a taxi company, so I can
watch our base station monitor and see what the message flow is like.
You can identify message types when you understand the system better,
but the only clear text (again, AFAIK) is when dispatch sends a text
message to an MDT head.

I have no idea how they are encoded, so sorry, can't help you there.
You might try befriending a techie at a taxi company and see if you
can wiggle access to the manuals. You might even ask your local taxi
company for a tour of their operations and data center (tell them your
interest in radio communications) and they might show you what the
monitor looks like and you might see a message flow.

And I have no idea about credit cards. The swipe reader (notorious,
even more so with this non-rectangular credit cards) are add-ons (at
least for our equipment), I would think that the software would at
least pack the CC# to save bandwidth, if not encrypt it entirely.
They know how many scanners and thieves are out there.

DDS is the biggest and best dispatch system for taxis (yet again,
AFAIK), we use it as does our biggest competitor (two major players,
several mom & pops). Our config requires 4 PCs in the computer room
to run the back end. It's quite a setup.


(Mark) wrote in message . com...
A local taxi company uses a data-dispatch
system made by DDS, whose website is at:

http://www.digital-dispatch.com

The data might be encrypted, but why would
a cab company encrypt? Their data isn't
likely to be of much interest to outsiders.
So I'll assume that it's unencrypted. I'd
like to try reading the data transmissions,
as an experiment. Does any of you know
where on the web or in print I should look
for information on how to read the taxi
data transmissions?