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

[Љубомир С. <lj...@gm...>]

I'll try to test transmitting with another usrp2 tomorrow, as soon as I wake
up :) But so far I can say that when OpenBTS is running both leds (A and C)
are turned on.

2011/6/10 Thomas Tsou <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
>