Re: [Openbts-discuss] Device doesn't see network at all (openbts-uhd + usrp2 + wbx)

[Thomas T. <tt...@vt...>]

2011/6/10 Љубомир Самарџић <lj...@gm...>:
> Hi,
>
> I don't have any sim that has no local roaming contract, but I tried the
> opposite: to act as a network from a neighbour country (and all local
> operators do have roaming contracts with that network). So at least I
> expected the OpenBTS to be listed. Also, I tried with different sims of all
> three local operators (and all possible sim+device combinations :) ). And of
> course, manual search (expecting to see the network).

In my experience, the sims are rarely an issue as long as the phone
accepts it. I have a mixed bag of sim cards, mostly from Asia, that I
use at random.

> This is config:
> http://pastebin.com/knwDVC9a

I ran the same config with wbx on usrp2 and usrp1 and my phones picked
up the signal within a few minutes. I do have one phone though -
Blackberry 7290 - that only very rarely finds the BTS signal, but
works fine once it does. I somewhat suspect a clock issue, but the
7290 has similar difficulty on the E100 and N200 (both with TCXO); I
haven't tried external clocking.

> After playing with power parameter I've got for the power:
> current downlink power -7 dB wrt full scale
> current attenuation bounds 7 to 7 dB

Ok. I'm in an area with weak GSM signals, but I'm able to detect the
BTS signal at higher attenuations with a 50-ohm terminator. Do you
have access to a spectrum analyzer or another usrp? I would expect
usrp related errors to appear in the TRX log, but it would be useful
to verify that the device is actually transmitting.

  Thomas