On February 11, [EMAIL PROTECTED] said:
>
> Kind of off-topic, but..
>
> Does anyone knows what is the modulation of these modems in cell-phones?
> read somewhere that the GSM models are not really modems since they only
> send the digital data that is received, but what modulation should the
> other end support to accept such connections?
>
> The same question to the modems in C/TDMA phones, does anyone know?
>
> TIA,
You'd be better off looking up phone tech on the web to get the proper
answer to this, in a forum where it's on topic. However. From what I
can recall, since it's been quite a while since I've worked on GSM
systems, the modulation doesn't really come into it. GSM is an
entirely digital system; everything sent over the wire, so to speak,
is sent as bits. 9,600 (baud? bits per second? not sure here) is the
upper limit of bandwidth as defined in the 1992 GSM spec, but that's
been increased lately AFAIK, and is set to go to some silly sort of
speed once the 3G specs kick in (shortly before hell freezes over, at
current rates of progress). At the "landline" end of things,
i.e. where your mobile signal touches down, the GSM switch does the
handshaking necessary to talk to the modem you're calling before
switching your data channel directly down to the modem. I suspect
other digital cellular systems such as CDMA and DAMPS work the same
way.
Waider.
--
[EMAIL PROTECTED] / Yes, it /is/ very personal of me.
I really need to reinstate the witty comments, dammit.
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