[Openbts-discuss] OpenBTS 5.0 + USRP B200

[Gerhard <ope...@gk...>]

Hello,

I'm struggling to get OpenBTS 5.0 with an USRP B200 to work. After I
have build, installed and run OpenBTS, all I get is the network showing
up on my Android device. When I try to connect to it, it fails (even
with open registration enabled). There are no hints in the logfiles. The
"tmsis"-table stays empty.

I found mails of people with the same issues.[1] However thy got it
working by increasing the performance of the virtual machine. This did
not work for me.

Another mail said that the internal clock of the B200 is way to bad for
using it with OpenBTS.[2] Is that so? How can I find out, if the clock
is causing the issues?

The OpenBTS book and several other sources state to set "rxgain" to 0-10
for USRP devices. However, Matt Ettus said (regarding the gain of a
B200) via the USRP-users mailing list: "0dB of gain is unusably low. You
should be using at least 40dB unless there is a very strong signal."
What value should I use?

My setup is
* Ubuntu 12.04.05 LTS Server (32 bit)
* OpenBTS 5.0 ($ ./switchto.sh 5.0)
* USRP B200 (no external clock)
* UHD 003.009.000
* No Antennas attached (Phone is next to the USRP)

Did I miss something obvious? I played with settings like "Band", "C0",
"power", "rxgain" even "RSSITarget", but no luck. I tried my setup with
and without antennas. Still no luck.


Any help is welcome


Cheers!
  Gerhard


[1] http://sourceforge.net/p/openbts/mailman/message/34400070/
[2] http://sourceforge.net/p/openbts/mailman/message/32682034/