3 Mar
2017
3 Mar
'17
11:16 a.m.
Hi.
There's been few updates to osmo-bts-trx recently so I've decided to get
back to https://projects.osmocom.org/issues/1648 and it seems like it's
completely broken:
- the "multiplexing" option (osmo-trx -m -c 2) which used to work now
leads to startup error of osmo-trx
- the "separate channel" option (osmo-trx -c 2) which wasn't working
properly but at least phone could see the network, now leads to
situation where no network is visible
Am I missing some magic combination of .cfg and command-line parameters
which could make it work? Am I using too old version of uhd or smth else?
The hw has not changed (usrp b210 + external 10MHz reference clock) but
maybe I've got to do some calibrations on it?
Any ideas as to what could be causing those regressions?
Is there anyone out there for whom some multi-trx setup is working? If
so, I'd like to compare notes to understand why it isn't working form me.
--
Max Suraev <msuraev(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Director: Harald Welte
3 Mar
3 Mar
11:59 a.m.
Hi Max,
Multi-trx works properly with UmTRX which is our reference platform. We've
also done partial testing with OpenCellular - spectrum analyser showed that
TX is fine, but we haven't tested with a phone. With UmTRX we tested
everything.
Since OpenCellular is a B210 derivative, it should work fine as well.
Could you try adding -x option to osmo-trx to enable external clock? If you
have a spectrum analyser, I would recommend you to use it to test the
signal and frequency offset of the signal.
On general, if everything starts and you don't see a network, it's most
likely a clock or RF issue.
For -m option fail it would be great if you create a ticket and attach logs.
Please excuse typos. Written with a touchscreen keyboard.
--
Regards,
Alexander Chemeris
CTO/Founder Fairwaves, Inc.
https://fairwaves.co
On Mar 3, 2017 12:17 PM, "Max" <msuraev(a)sysmocom.de> wrote:
Hi.
There's been few updates to osmo-bts-trx recently so I've decided to get
back to https://projects.osmocom.org/issues/1648 and it seems like it's
completely broken:
- the "multiplexing" option (osmo-trx -m -c 2) which used to work now
leads to startup error of osmo-trx
- the "separate channel" option (osmo-trx -c 2) which wasn't working
properly but at least phone could see the network, now leads to situation
where no network is visible
Am I missing some magic combination of .cfg and command-line parameters
which could make it work? Am I using too old version of uhd or smth else?
The hw has not changed (usrp b210 + external 10MHz reference clock) but
maybe I've got to do some calibrations on it?
Any ideas as to what could be causing those regressions?
Is there anyone out there for whom some multi-trx setup is working? If so,
I'd like to compare notes to understand why it isn't working form me.
--
Max Suraev <msuraev(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Director: Harald Welte
12:17 p.m.
I've created https://projects.osmocom.org/issues/1963 and linked it to
1648 for -m issue.
I've tested with -x and external clock already. Unfortunately I can't
promise to dig deeper with spectrum analyzer any time soon due to other
tasks at hands. Could you please attach your known-to-work config files
to #1648 so we have some reference point for future tests?
On 03.03.2017 12:59, Alexander Chemeris wrote:
Hi Max,
Multi-trx works properly with UmTRX which is our reference platform.
We've also done partial testing with OpenCellular - spectrum analyser
showed that TX is fine, but we haven't tested with a phone. With UmTRX
we tested everything.
Since OpenCellular is a B210 derivative, it should work fine as well.
Could you try adding -x option to osmo-trx to enable external clock?
If you have a spectrum analyser, I would recommend you to use it to
test the signal and frequency offset of the signal.
On general, if everything starts and you don't see a network, it's
most likely a clock or RF issue.
For -m option fail it would be great if you create a ticket and attach
logs.
--
Max Suraev <msuraev(a)sysmocom.de> http://www.sysmocom.de/
=======================================================================
* sysmocom - systems for mobile communications GmbH
* Alt-Moabit 93
* 10559 Berlin, Germany
* Sitz / Registered office: Berlin, HRB 134158 B
* Geschaeftsfuehrer / Managing Director: Harald Welte
4:38 p.m.
On 03/03/2017 13:17, Max wrote:
I've tested with -x and external clock already. Unfortunately I can't
promise to dig deeper with spectrum analyzer any time soon due to
other tasks at hands. Could you please attach your known-to-work
config files to #1648 so we have some reference point for future tests?
On 03.03.2017 12:59, Alexander Chemeris wrote:
> On general, if everything starts and you don't see a network, it's
> most likely a clock or RF issue.
>
Hi all, I may be way off here, but maybe worth saying, three days ago
trying to track down probs with AMR, I compiled and tested everything
from master, all deps + osmo-bts-trx and osmo-trx. I ran against my
standard nitb on another box though.
osmo-bts at 75852294
osmo-trx at 2dee3e99
Everything stated up fine but phones saw no network.
So I checked the RF with an RTL-SDR and I had a very narrow band
"silent" signal in the centre of the channel until I manually set
osmotrx tx-attenuation in the vty:
phy 0
instance 0
osmotrx tx-attenuation 35
I mention it because your latest cfg attached to the ticket has
osmotrx tx-attenuation oml
which is also the default I believe, in the absence of the command in
the cfg. and it didn't work for me.
At time I just presumed it should with a newer nitb.
I only have an N210 so I can't test multi-trx :-(
k/
7:07 p.m.
On Fri, Mar 3, 2017 at 3:16 AM, Max <msuraev(a)sysmocom.de> wrote:
There's been few updates to osmo-bts-trx recently
so I've decided to get
back to https://projects.osmocom.org/issues/1648 and it seems like it's
completely broken:
- the "multiplexing" option (osmo-trx -m -c 2) which used to work now leads
to startup error of osmo-trx
- the "separate channel" option (osmo-trx -c 2) which wasn't working
properly but at least phone could see the network, now leads to situation
where no network is visible
I'm looking into these issues. The startup error in the first case is
my first concern. The second issue should be straightforward to test.
I will be using the config files in the ticket unless somebody
suggests otherwise.
-TT
2672
days inactive
2672
days old
4 comments
4 participants
participants (4)
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Alexander Chemeris -
Keith -
Max -
Tom Tsou