OpenBTS starts and transmits "something", but not a valid GSM signal. However it is on the the frequency I have the GSM license for and that I had preset anyway, from my regular OopenBTS installation.
What does "Please ensure you have `sync libbladeRF' built and installed. https://github.com/Nuand/bladeRF/tree/d ... adeRF_sync" mean? The link seems dead, and anyway I do not know what I should do here I only have latest bladeRF master installed.
At the time of the writing, the sync calls were not part of master. As of this past weekend, they became part of master. So please disregard that message.
As for the problematic signal, I think there may be a bug somewhere in writeSamples() in the bladeRFDevice.cpp file. I'm having a look at it right now.
I will push changes up if we see anything concrete.
Now I can find the cell, but it seems not to hear my logon attempts. Noise command gives always -32 to -33 dB, rxgain setting seems to change not very much. I do not have here at work the equipment to look deeper into it, will give it another try this evening at home.
The downlink signal is now clean and looks perfect, the mobiles find the network immediately and transmit access bursts, but they are not heard by the bladeRF. The transmitter is fixed (although output power looks a bit weak), now it is time to take a look at the receiver
Still the BTS does not hear my uplink signals. Latest changes in bladeRF did not change this. Any news, any ideas how to debug this? The almost fix noise value of -32dB looks strange, and the behavior of the rxgain command in OpenBTS cli is strange, too.
Using other hardware OpenBTS runs just fine on my machine, USRP1 or RAD1/SDR1 do a great job for GSM.
Yep, downlink is just fine here, just the uplink does not work at all. What does the command "noise" tell in your setup?
All the other stuff, smqueue, subscriber registry and yate do work here, when using other hardware like the USRP1 I can make phone calls, transmit SMS, use the internet via GPRS, so my setup in general appears to be fine, also I do have already some experience with OpenBTS.
Btw., I am allowed to do this, I have a GSM test license
So your value is even more crazy than mine. Are you using 900 or 1800 MHz? My license allows only 1800 MHz, but I will make a 900 MHz test without antenna, to learn how noise looks in this band.
OpenBSC with SDRs looked to me a bit complicated and too large for a simple single site setup, so I am quite happy with the simple OpenBTS solution.
What are your values? Yes that is for the 900 band.
For 850 I get:
noise RSSI is -14 dB wrt full scale
MS RSSI target is -50 dB wrt full scale
For 1800 I get:
noise RSSI is -26 dB wrt full scale
MS RSSI target is -50 dB wrt full scale
For 1900 I get;
noise RSSI is -25 dB wrt full scale
MS RSSI target is -50 dB wrt full scale
Yes I tried to get OpenBSC working with the BladeRF but I was so unsuccessful it's not worth going into further
I just wish OpenBTS can register on IMEI if you don't have the IMSI.
I am using open registration, with a .* as regular expression; I do not want to bother handling IMSI numbers for simple tests without any security relevance.
Still I can't find anyone who is able to register with a handset using the bladeRF TRX. My access bursts keep unheard, the bladeRF does not receive them.
I can't do any physical tests at the moment as I am away from my set-up and have been remoting in to get the noise results.
Where does OpenBTS display a list of all registered handsets?
The command "tmsis" goives a list of registered phones, and when GPRS is enabled, "sgsn list" gives the pdp contexts.
In my setup the phones can find the test network, and when trying to register they transmit their access bursts, but there is no response, no acknowledge.
Thanks for that, is this info stored in a database somewhere?
Yes I am seeing the same thing. Even locking the handset to ARFCN and band. The BladeRF just doesn't hear anything.
Do you think this is a problem with the Nuand or the OpenBTS software?
/etc/OpenBTS/ holds the openbts.db, the settings file. There the path to the tmsitable is set...I do not know the default value, I have changed this path a long time ago.
/var/lib/asterisk/sqlite3dir/ holds the subscriber registry.
I have no idea what exactly the problem is, but my guess is the bladeRF specific transceiver file in the nuand branch of OpenBTS.
I only have latest bladeRF master installed.