Hi Peter,
It means that some real programming is needed.
It's not a small
change. It might work as-is with one phone camping to only one of the
two BTSes at a time, but you will likely have corruptions if you have
a bunch of phones on both BTSes at once.
I was able to start two InSite units at the same time, probably
because these units has only one TRX per BTS. I was even able to
establish an inter-BTS voice call. Cell reselection and SMS was
working fine also.
But when I tried to enable handover, I got this strange message that I
have to enable RTP proxy. If I do so, my voice calls are failing
completely (not a surprise, these units are connecting through E1). I
could really use a straight answer from any developer, that OpenBSC has
handover support for non-IP (E1 based) units or not, because I am not
trying to get this done if it is completely missing.
When using nitb with a multi-TRX MetroSite there is a
similar pattern
to what you describe - after the BTS is reset using the Nokia BTS
Manager, nitb only ever manages to correctly initialize the first
TRX. An error occurs and nitb exits. Restarting nitb sometimes allows
it to initialize the second TRX, sometimes no. My guess is that
failure or success depends on what phones are sending to the BTS
meanwhile, but it could also be only a matter of timing.
Today I was able to setup our MetroSite (2 GSM1800 TRXs) unit and encountered the very
same problem: only the first TRX was initialized, though both TRXs are
set up in the openbsc config file. For the start and stop process you
absolutely right. Out of ten tries, usually 2-3 are successful if I
try to start both InSite units, but the chances are better if I
previously start openbsc with a single BTS config file, then hit
Ctrl+C and start the mutli BTS config file. It is also interesting,
that both TRXSIG lapd connections are ON according to the BTS manager
with MetroSite, but the second TRX is just not working.
The nokia_site code can definitily be improved when it
comes to
startup/shutdown, but I don't know how well known the Nokia OML is.
It would also be nice to listen to the BTS Manager
serial port
communication. If I understand correctly, many (all?) things that
BTS Manager can do over serial are also possible over E1.
I can do these traces if you let me know what commands are you
interested in. For example I can tell you for sure, that the site
reset request command sent by OpenBSC (bts_nokia_site.c to be
specific) is doing exactly the same, when I hit "Enable Abis" in Nokia
BTS Manager.
BTW do you have Nokia units too?
I am still open to give access to our MetroSite (or
the InSite) units if a developer is interested in it.
I also have a fine selection of Nokia BTS managers that includes
almost all Nokia BTS types (InSite, MetroSite, UltraSite, Flexi HUB,
MetroHUB, Flexi EDGE, Metro Hopper etc.) I am happy to share this with any developer,
just PM me with an FTP server account and remember: the whole package
is 2.2GB.
Br,
Csaba