Calypso/Iota/Rita chip recommendations

Michael Spacefalcon msokolov at ivan.Harhan.ORG
Wed Aug 14 22:00:02 UTC 2013


Peter Stuge <peter at stuge.se> wrote:

> > Actually my hope is to build a quad-band phone
> That would be neat too.
> [...]
> I was thinking about phone-as-BTS, but same principle, no
> (or just the appropriate) filters.

Unfortunately these two goals (quad-band support on the one hand, and
filter hackability on the other hand) seem to be in conflict.  It
seems to me that trying to build a quad-band phone using separate
antenna switch and Rx SAW filter components would be very messy,
probably too messy for an RF-clean PCB layout - hence necessitating
the use of an integrated RF front-end part that has all that mess
hidden inside.  (See ftp.ifctf.org/pub/GSM/Calypso/M034F.pdf for an
example of wha I mean.)

But using an integrated RF FEM like that M034F would surely preclude
the possibility of filter hacking...

Once again, my goal is to produce a Totally Free Phone for everyday
use in one's pocket/purse, not GSM hacking - and I reason I must not
be the only person on this list who desires such; I reason that there
must be other lurkers on this list who watch with frustration as the
years go by, there are all kinds of hacks made, but virtually zero
progress toward an end-user-usable Free phone.

It's obvious that OsmocomBB and FreeCalypso will always be two separate
projects: the former focused on GSM hacking and security research, the
latter on everyday-phone end-user needs.  All I'm hoping for is that
the two projects could be at least somewhat amicable, and cooperate in
things like amassing hardware knowledge - rather than be all-out
hostile.

SF




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