First of all, it is normal that the USRP is not detected anymore with the uhd tools when it is claimed by OpenBTS. So this looks not alarming.
Are you able to verify if RF is transmitted? Is there some spectrum analyzer available, or a receiver that can tune into the used GSM frequency, best is AM mode and open squelch, to see if a carrier is present? This way you can find out if it transmits at all, and if so, it must be continously, uninterruptes, without stuttering.
I assume your successful tests used the very same USRP, so the frequency should not be off too far?!
From: Zamrath Nizam [mailto:address@hidden
Sent: Tuesday, March 24, 2015 5:33 AM
To: address@hidden; GNURadio Discussion List
Subject: [Openbts-discuss] -------'Range' network is not detected-------
I have recently installed OpenBTS-2.8 on a Banana-Pi (Processor: ARMv7) board for USRP N210 functioning. All the prerequisites including GNURadio, UHD were successfully built on the board prior to OpenBTS installation. With all configurations done, still there is a problem in the USRP connection.
I have configured MCC, MNC and ethernet IP connection. "ping 192.168.10.2" works fine. Once the ethernet connection is established and until "./OpenBTS" is executed, "uhd_find_devices" and "uhd_usrp_probe" detect USRP. After the execution of "./OpenBTS", surprisingly "uhd_find_devices" and "uhd_usrp_probe" do not detect the device and say "No device found..." ('ping' is still working though). The strangest thing is even at this stage, "./OpenBTS" works fine even at a re-run.
After all these drama, no ('range') network is detected by a properly configured mobile phone. (Note: We have successfully placed calls and SMS with almost same procedure using a PC instead of B-Pi).
I am bit confused here whether this is a deal of OpenBTS or GNURadio. Does the processor speed come in to play in this scenario?
Any valuable suggestions would be highly appreciated.