Possible answer to SOME of the AT&T gsm problems

Mike Hodson mystica at gmail.com
Tue Aug 7 04:12:16 CEST 2007

Hmm.. This thread is rather troubling for those who are testing in
markets where GSM850 is the only spectrum AT&T owns. This, by itself,
is less of a burden due to most markets being dual-band, however, god
only knows how that will affect coverage during peak times when 1900
is totally booked for timeslots.

On 8/6/07, Ian Darwin <ian at darwinsys.com> wrote:
> That's odd. Other quad-band phones are sold publicly in the US by
> high-profile sellers. See for example
> http://www.palm.com/us/products/smartphones/treo680/specs.html

This is not exactly what the previous person was meaning when he said
(and i paraphrase how i think you interpreted it) 'selling a quad band
phone is illegal.'  The frequency band itself is not, ATT uses it
quite a lot.  Other approved devices using quad-band are not illegal,
but simply selling a device that has not yet been 'approved' by the
FCC, that uses said band, IS illegal.  Engineering samples that the
phone companies use to test are not exactly under this, as they are
not 'buying' as a consumer.  The open development/debugging of Moko
means that developers must 'buy' devices, and this causes all sorts of
fun to happen.

As has been stated before, even though the radio itself that the phone
is based upon is FCC tested, approved, and is quad-band, that does not
mean the FCC will approve every single device, on every single band,
that is made with this radio; the whole rig (phone/antennas) has to be
tested for FCC compliance... Perhaps this phase of testing is still
waiting approvals for 850mhz, i am unsure.  All is speculation with
regard to the 1900-onlyness, short of the 'fcc approval on the entire
device' bit.. This has held up phones before from being released to
consumers by american carriers, for phones they have tested themselves
to no end before handing to the FCC.   Using the phone as quad-band
should not violate any laws; selling it to consumers as quad-band
without being approved as such, would.

> I imagine that any multi-band phone will listen on all its frequencies
> before it tries to register, and will therefore only transmit on
> frequencies that are in service in that area.

I too imagine that is the way it works; unless there is something set
in the firmware of said multi-band modem to prevent 850 so as not to
be fined by the FCC or somesuch.

> That said, I wonder why they (FIC and/or the FCC) didn't put the lower
> frequencies (850/900MHz) in the approval?
We can only speculate, until someone actually tells us...  I speculate
that its in the process, but has not been finalized yet.


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