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.
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@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@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
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.
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/
On Fri, Mar 3, 2017 at 3:16 AM, Max msuraev@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
-
Alexander Chemeris -
Keith -
Max -
Tom Tsou