Re: [Openbts-discuss] Can't register MS on a fresh OpenBTS 5 install

[Ralph A. S. d. <ra...@sc...>]

Then it is some issue earlier in the chain, not an authentication/registration problem. I had this when the new UHD with different group delay came, and it worked again when openbts got patched respectively. For some reason your setup even does not properly decode the access bursts. 

 

Ralph.

 

From: Thomas Meghe [mailto:tho...@gm...] 
Sent: Tuesday, February 9, 2016 6:53 PM
To: Ralph A. Schmid, dk5ras
Cc: ope...@li...
Subject: Re: [Openbts-discuss] Can't register MS on a fresh OpenBTS 5 install

 

Apologies for this second email but, I managed to catch access burst on uplink frequency (cf https://framapic.org/IL7FgT9V35di/YrzHY5d4014s.png) but there is only one or two packet sent.

 

2016-02-09 18:44 GMT+01:00 Thomas Meghe <tho...@gm... <mailto:tho...@gm...> >:

Hi Ralph,

Thanks for your answer. rxgain was set to 10 (accordingly to the doc regarding USRP hardware), I tried to set it to 0 which is 10db below. Nothing is different.

 

I also tried without the antenna plugged and it still doesn't work. I didn't manage to find some crappy speakers at home, I will try elsewhere. However, I can clearly see the downlink of the BTS corresponding to the ARFCN 80 (which is 951mhz cf https://framapic.org/zBlgtJB20AfI/EuZAcpYj0duQ.png) but nothing on the uplink (906mhz) when trying to register MS.

 

Regards.

 

2016-02-09 14:35 GMT+01:00 Ralph A. Schmid, dk5ras <ra...@sc... <mailto:ra...@sc...> >:

What is your rx gain setting? Try using 10 or 20 dB below the preset. Also try disconnecting your RX antenna when you are very close to the B200 during the tests. Sometimes the access bursts simply are not decoded because the signal is too strong. 

 

Can you monitor what the handheld transmits when trying to register? Only access bursts, or a complete SDDCH exchange? You can get an idea if you put the phone on EMI sensitive PC speakers or a cheap radio clock, to hear the annoying GSM noise when it transmits. Access bursts are very short, barely noticeable clicks, only two or three of them in a row, while an established SDDCH produces the typical machinegun / drum machine "tack tackatack tackatack" sound, like when receiving a short message in a commercial network. 

 

Ralph.

 

From: Thomas Meghe [mailto:tho...@gm... <mailto:tho...@gm...> ] 
Sent: Tuesday, February 9, 2016 12:33 PM
To: ope...@li... <mailto:ope...@li...> 
Subject: [Openbts-discuss] Can't register MS on a fresh OpenBTS 5 install

 

Hello,

I'm currently trying to setup a working OpenBTS 5 testing setup (for testing purposes) on a Ubuntu 14.04 64 bit with a B200. What I've done so far :

*	Setup OpenBTS 5 following the guide "Getting started with OpenBTS guide"
*	Everything seems to be functionnal (no compile error, no running error, radio com with my B200 operational)
*	Kept MCC and MNC to testing default values (001 01)
*	Control.LUR.OpenRegistration set to *.
*	Control.LUR.SendTMSIs set to 1
*	sipauthserve running
*	noise RSSI is -79 dB wrt full scale
*	power downlink is set to -10db
*	ARFCN is set to 80 (checked before with OsmocomBB scan that the associated frequency was not noisy, I can see from my osmophone a nice and clear peak)

I think I didn't missed anything for the crash-test but... I tried to connect on 3 different phones with 3 different simcards (My current one on my Android phone, an old one and a foreign one). All my 3 phones can see the network but no one is able to connect to. The connection process is long and fall short to a "not available" or something else.

I'm using my B200 with two Vert 400 antennas (it shall be enough to cover the living room area)

Thanks for any help and regards,

Tom