GSM data connections

[nibot]

So, I've long been assuming that I would be able to make dial-up data (V.32, you know, like in the old BBS days) connections over my GSM telephone, using the telephone's internal 'modem'. However, I've never gotten it to work. The phone never connects:

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It turns out that it's not possible with my provider. When you make a data connection to a traditional modem over a GSM telephone, what actually happens is that you transmit your data over the GSM network and then, somewhere at the wireless company, there is a modem that actually originates the modem connection over normal phone lines. This is called CSD — Circuit Switched Data. The 'modem sounds' are not going over the wireless connection. This makes a good deal of sense, because (1) the wireless connection is already digital, and (2) the coding system is optimised for voice and would probably mutilate a V.32 signal beyond recognition.

AT&T Wireless does not support CSD. They have not even installed the hardware for it.

Other providers (Cingular, reportedly, is one) do support CSD. There is a fee of $4 to $10 to enable it. Once CSD is enabled, you can make data calls, and they come out of your usual supply of 'minutes.' This means you can dial up your ISP over the mobile telephone for free during your 'unlimited nights and weekends.' This is simply not possible with AT&T.

The way data is supposed to go over GSM is with GPRS (General Packet Radio Service), where your phone actually gets an IP address, and you have packet-switched (as opposed to circuit-switched) access to the network. However, AT&T charges something like $8/mb for this service — entirely ridiculous. My brother pays $15/month for unlimited GPRS usage with his provider (Sprint??).

Anyway, these are the things one learns after signing the 1-year contract. S-: