OpenBTS5 and USRP2 not working ( USRP is transmitting ), but uplink timing is off

[evertverduin]

Hi All,

I am trying to get openBTS 5 to work with the USRP2, but i am unable to get the uplink working. The USRP2 is gps locked.
I cannot see any immediate assignments coming from openBTS ( log files ) caused by the RACH burst from the mobile. I can see the mobile transmitting ( on my analyser ), but there is no SDCCH immediate assignment from openBTS. I see the network, sim card is properly configured. There is no interference on the channel -> checked ( private GSM ). I assume the RACH is never heard by openbts due to timing issues. How can this be resolved, or what am i doing wrong?

Evert