OpenBTS USRP2 support

11/17/2010 07:09 AM

I'm announcing the availability of USRP2 support with OpenBTS. The
patch set consists of a new device implementation that uses the UHD
driver from Ettus Research and allows the use of an external 10MHz
reference clock. Additional implementation details can be found in the
comments and commit log.


git clone git://

git clone



USRP2 support requires the UHD driver and firmware. GNU Radio is not required.

./configure --with-uhd

Without the '--with-uhd' option, the standard USRP1 implementation
will be built.

Release Notes:

*The USRP2 is clocked at 100MHz and does not output fractional sample
rates, so only the non-52M Transceiver is available.

*Tested with a single WBX board, which is capable of operation on all
4 GSM bands. Other boards should work, but are untested.

*Operation in the upper bands (1800, 1900MHz) requires an external
reference for reliable operation. This is true to a lesser extent in
the lower bands as well.

External Reference Clock:

The front panel 10MHz reference input of the USRP2 can be used to
improve stability of the internal oscillator (~20 ppm). To test
frequency offset, a modified version of Kalibrate - - is available. Information and examples for
the UHD development branch can be found here.

That's about it. Hopefully, a number of people will find this useful.
Let me know if you have any questions. Comments and feedback are
always welcome.