Software mobile phone

Dear All,

Do we think it is possible to create a software mobile phone using the
USRP, with the OpenBTS code or something else?

I mean everything would be in software, plus the USRP…?

Abdalaleem

Dear All,

Do we think it is possible to create a software mobile phone using the
USRP, with the OpenBTS code or something else?

I mean everything would be in software, plus the USRP…?

It is absolutely possible. So far I don’t know anyone who has
tried to do it. The OpenBTS code would give you a big head start.

I also think it would be interesting to port the resulting code into a
mobile phone. Generally the GSM protocols in a phone are run in a
“baseband processor” separate from the user interface processor.
Every phone I know of uses secret, proprietary code running in the
baseband processor, even when the user interface is largely free
software. Once you had working code running in GNU Radio on a Linux
machine, the challenge would be finding a well-documented baseband
chip (in which the manufacturer tells you where to find the radio I/O
gear on the chip, and how it works, etc). Porting clean GSM code to
run in that chip in realtime would require some adaptation to exploit
unusual on-chip DSP hardware, mastering an embedded debugging
environment, and perhaps shrinking the memory consumption of the GNU
Radio-based code.

I think it’s not only doable, but well worth doing. It should be
worth a couple of PhDs at least. You would certainly know the GSM
protocols inside and out by the time you were done!

John

And leveraging the work from the osmocombb project
(http://bb.osmocom.org/trac/) will get you a far ways towards the goal.

Quoting John G. ([email protected]):

Fantastic stuff!

Hi,

The OpenBTS code would give you a big head start.

The tranceiver part sure. But you’d still need pretty big modification
to have it act as a TDMA clock slave and not TDMA clock master (that’s
quite different).

Once you have done the L1 inside the USRP somehow, you can re-use the
osmocom-bb code (which is an opensource baseband implementation project)
for the upper layers.

Sylvain M.

This forum is not affiliated to the Ruby language, Ruby on Rails framework, nor any Ruby applications discussed here.

| Privacy Policy | Terms of Service | Remote Ruby Jobs