[Gta04-owner] Detect Call Hangup / Option Datasheet

[Dr. H. Nikolaus Schaller]

Am 01.01.2012 um 21:29 schrieb Marcel Holtmann:

> Hi Nikolaus,
> 
> <snip>
> 
>>>>> form factor. Or you start looking at getting Telit or IFX based modems.
>>>> 
>>>> We did that and at the time we decided, their modems were horribly
>>>> big. So we would have had to sacrifice the handsfree speakers to
>>>> get it into the existing case...
>>> 
>>> The Telit modem is indeed not small. At least the ones that I have seen
>>> so far.
>>> 
>>> And most likely Infineon (actually Intel now) might not wanna give you a
>>> good deal or small quantities for the 6260 or similar modems. Have you
>>> tried to ask?
>> 
>> Only with manufacturers of complete modules. The key issue we have
>> is that we need a module and not a chipset. I.e. we can't build our
>> own modem.
>> 
>> With a chipset and access to the firmware we would have to pay for
>> full FCC and R&TTE certifications... With a complete pre-certified 
>> module we simply write "contains FCC ID abcdef".
> 
> you might be right here. I don't think we ever got the IFX modem as
> module.
> 
> On that topic of modules, why do you guys went for USB based module and

> not some SDIO or similar bus? The USB can be pretty power hungry. And

We have to use what the module provides. There is no choice... All UMTS
modules I have seen so far appear to provide a USB interface.

USB 2.0 = 480 MBit/s on 2 wires.
SDIO = ? MBit/s on 6 wires.

> even USB auto-suspend might be a problem when you have to wake it up
> again for cell change or signal strength notifications.

We have not noticed a problem with that so far. Suspend/wakeup is done
automatically by hardware (EHCI controller + ULPI).