Cellular Network Infrastructure » Radio Access Network » OsmoBTS

Posting in osmo-bts as I assume it is an osmo-bts issue, although it is observed with osmo-trx-lms as I don't currently have any other TRX hardware.

How to reproduce:
Bring up a BTS with osmo-trx-lms

such as:

while [ 0 ] ; do sleep 1; sudo osmo-trx-lms -C osmo-trx-lms.cfg; done

# osmo-bts doesn't exit anymore, put it it a loop anyway:
while [ 0 ] ; do sleep 1; osmo-bts-trx -c osmo-bts-trx.cfg ; done

Once the BTS is up, drop it from the BSC:

drop bts connection X oml

The bts will ramp the power down, then finally issue RFMUTE then start to bring it up again:

A bunch of stuff will happen here, that may or may not depend on the config, but the point is that eventually we get to:

Sun Dec  5 14:42:06 2021 DTRXDUL FATAL <0004> Transceiver.cpp:1309 Something went wrong in thread RxLower, requesting stop                               
Sun Dec  5 14:42:06 2021 DTRXCTRL INFO <0002> Transceiver.cpp:1031 [chan=0] response is 'RSP POWERON 0'                                                  
Sun Dec  5 14:42:06 2021 DDEV INFO <0005> LMSDevice.cpp:159 Closing LMS device                                   

osmo-trx-lms exits and the shell restarts it:

Then we will see:

Sun Dec  5 14:42:09 2021 DTRXCTRL INFO <0002> Transceiver.cpp:877 [chan=0] command is 'POWERON'
Sun Dec  5 14:42:09 2021 DDEV INFO <0005> LMSDevice.cpp:390 starting LMS...
Sun Dec  5 14:42:09 2021 DDEV ERROR <0005> LMSDevice.cpp:261 Power parameters requested before Tx Frequency was set! Providing band 900 by default...

ad infinitum...

Also if the sleep in the TRX loop is increased to say 5 seconds, then when osmo-trx-lms starts again, the BTS
has logged Shutting down BTS, exit 1, reason: No clock since TRX was started. and now needs manual intervention.
In this state, dropping the BTS just results in:
BTS_SHUTDOWN(bts0)[0x5618af2268f0]{WAIT_RAMP_DOWN_COMPL}: BTS is already being shutdown.

I now have to CTRL-QUIT the osmo-bts-trx process or killall -[3|9] osmo-bts-trx or somesuch :(

I could attach entire logs/configs et al, but I'd be very surprised if this is not 100% reproducible.