OpenBTS internal clock (Ettus USRP B100)


I’ve got an Ettus USRP B100 device which can be configured to use an
internal 52MHz clock to operate. However after compiling and testing
OpenBTS, it uses 64MHz clockrate. Can anyone explain why that’s the
case? Is there any possibility to change the clockrate to 52MHz?

Cite from OpenBTS wiki:
“The current release of OpenBTS supports the B100 series with a 64 MHz
specific polyphase resampler and updated GSM receiver design. These
changes resolve various issues previously seen with B100 and earlier
versions of OpenBTS, which were due to sample rate issues and level
There’s no further information about that.

I can change the clockrate of the B100 to 52MHz by using the command
uhd_usrp_probe --args=“master_clock_rate=52e6”
Unfortunately OpenBTS still uses the different clockrate.