On Wed, Jun 15, 2016 at 11:19 PM, Tom Tsou tom@tsou.cc wrote:
On Wed, Jun 15, 2016 at 12:50 PM, Alexander Chemeris alexander.chemeris@gmail.com wrote:
diff --git a/src/osmo-bts-trx/trx_if.c b/src/osmo-bts-trx/trx_if.c index a4c16dc..8c9a839 100644 --- a/src/osmo-bts-trx/trx_if.c +++ b/src/osmo-bts-trx/trx_if.c @@ -47,7 +47,7 @@ //#define TOA_RSSI_DEBUG
int transceiver_available = 0; -int settsc_enabled = 0; +int settsc_enabled = 1; int setbsic_enabled = 0;
Could you explain why is that required?
Because osmo-trx only supports setting the training sequence through the SETTSC command. There is some history of the code that I am not familiar with. There is a SETBSIC command on the osmo-bts side of the interface, but that command does not exist in osmo-trx side. Perhaps SETBSIC previously existed in OpenBTS at one point in time?
SETBSIC was introduced for osmocom-bb-trx (an OsmocomBB phone operating as a BTS). These phones didn't have a function to set TSC, but had a function to set BSIC, so Andreas added SETBSIC command to work around this. OsmoBTS has sent both commands, because it doesn't know whether it's connected to osmo-trx or to osmocom-bb-trx - an unsupported command was historically just ignored. Has this behaviour changed recently? I don't think there is any issues with sending SETBSIC to osmo-trx except a warning in the log.
I don't remember the code exactly, but IIRC this is equivalent to setting or removing 'tsc' line in the config file.
I'm not aware SETTSC vs SETBSIC configuration outside of those static variables.
I was sure that I saw that removing "bsic" parameter stopped osmo-bts from sending SETBSIC, but now I don't see that in the code. That should be the best way to handle this - only send TSC of BSIC based on configuration.