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GPRS documentation

Hi All

where should I go for some documentation on the details of talking from an application to a mobile data terminal using GPRS? I can find lots of marketing white papers on how good mobile data is, but nothing that really addresses the programming details.

Thanks

on the move
Tuesday, August 10, 2004

GPRS is a bearer, not a protocol.  The GPRS conversation is between the mobile terminal (e.g. a Symbian smartphone) and the base-station.  Typically, the mobile terminal presents the Internet (or ISP-specific IP-based networks) to applications that run on the device (e.g. a web browser, or a custom business app or an online game).  Your applications do not need to understand GPRS itself.

This means that you can use normal webservers to serve content to mobile devices.  On the mobile device side, most mobile devices are programmable - e.g. java, or C++ or Brew or whatnot - so you can write bespoke apps if you want that kind of power and flexibility.  Otherwise, almost all mobile devices now come with quite capable conventional web browsers, ideal for normal intranet/internet type web applications.

i like i
Tuesday, August 10, 2004

I didn't give enough detail, sorry:

What I'm wanting to do is push data to a mobile data terminal (an iPaq) in a truck that's connected to the internet by a GSM cellular modem using GPRS. I believe I can use SMPP to send SMS messages to the cellular modem which get picked up by the iPaq. But can my (fixed) application open a socket to the iPaq to tell the truck driver to go to a different location? Or do I have to wait til the driver checks to see what he should do next? Or send an SMS message which makes the iPaq check?

on the move
Tuesday, August 10, 2004


I'm doing this now in the Metro DC area and have been working extensively with it for nearly 8 months.

When you connect to the GPRS network, you get an IP address.  Then, you can do just about anything you want to through this that you can do to any other Internet-connected device.

If you want some more details/info, drop me an email.

KC
Tuesday, August 10, 2004

Conventionally, most GPRS networks support 'client initiated connections' only.  No 'network initiated connections'.  This is because most of the gateways between the mobile network and the internet are doing NAT, hiding all devices on the mobile network behind a small pool of IP addresses on the internet side.

If you are inside the GPRS network (phone-to-phone) then push (UDP even) might work well.  Otherwise, you'll have to pay to get a proper IP address for your mobile device from your carrier.  Not sure what your possibilities are there in your area (I'm European, so everything mobile is so much superior over here).

i like i
Wednesday, August 11, 2004

Why can't you use the SMS as your push service? Given that you have 160 octets in a typical SMS message, you should be able to code a new address in a single SMS (esp if you compress it a bit).  Or you could just push a house number and postal code, and get your Ipaq to do a multimap lookup.

However you decide to do it, it should be fairly easy as sms effectively gives you a push service of up to 160 octets.

Best regards,

treefrog
Wednesday, August 11, 2004

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