- This topic has 13 replies, 1 voice, and was last updated 11 years, 8 months ago by lois.
26th November 2008 at 15:23 #54790MerGuest
OML = Operation & maintenace link (link with OMCR, for supervision)
my question is: if we have OML down, can BTS realated with it carry traffic
once I have see a BTS with OML down (OMC engineer see it(BTS) down and on the site OML LED blink), but BTS behavior (all LED’s for TRX, Abis and O&M) indicate that traffic is supported. it is possible ?
just OML LED NOK
note: OML was down because we had a faulty card in the BSC (I don’t know witch card)
network:Alcatel B9, BTS A9100, BSC G230th November 2008 at 10:44 #54791MangafullGuest
OML cut = BTS down
yes, OML is used for supervision but it also carry signaling, (no signaling=> no traffic). the behavior of BTS was good because O&M is up but if you restart BTS (switch off an on) you can see that your BTS is down.
you said:”OML was down because we had a faulty card in the BSC” = if BSC can’t control BTS = 🙂30th November 2008 at 10:55 #54792OMLGuest
I agree with mangafull, without OML communication can’t be established but how, this what I wont to know2nd December 2008 at 23:31 #54793SumithGuest
Some reare case I had noticed, with out OML Alcatel G4 bts is working. Problem with the SUMA card in most case. Not a problem with BSC(TCUC card related to OML: you can see from OMC). If you power reset the BTS OML back to normal. But after few days OML will fault again.11th June 2009 at 04:37 #54794OMLGuest
CLEAR26th June 2009 at 18:57 #54795TanujGuest
If OML is down it only means that OMCR is not able to monitor the bSC and BTS if the signalling with MSC is working then the bts and bsc will work fine, oml down doesnt mean traffic is down1st July 2009 at 10:10 #54796VitoGuest
If OML is down, BTS can carry traffic. OML down = no supervision.
SUMA board is responsible for supervision at BTS
NOC engineer1st July 2009 at 16:15 #54797krishGuest
then what it will affect ? will it not affect the traffic?1st July 2009 at 16:37 #54798RexGuest
If Abis is OK and OML down that means BTS still works with the configuration it has in that moment and will carry traffic. But, it’s not possible to control BTS from OMC-R (do any changes etc.), you can’t know what it happens with BTS, is it really working or not. Somebody should go to the site and reset BTS.1st July 2009 at 17:20 #54799KRISHGuest
THANKS CAN U TELL ME WHAT IS RF PERFORMANCE ALARM IN ERICSSON .IS IT RELATED TO VSWR?
(2)LOCAL MODE ALARM
(3) TS SYNC FAULT ALARM
(4) BTS INT AND EXT AFFECTED AND UNAFFECTED ALARM2nd July 2009 at 19:48 #54800RexGuest
I don’t know about Ericsson.
BR30th July 2009 at 09:24 #54801Muhammad AmirGuest
We are VSAT service provider for GSM operators, we are facing a OML fault alaram on our MSC end over our VSAT media. Can anyone tell me that it can be a media fault or it comes from BTS or MSC end.
we are using Ercisson BTS. when OML fault comes, our VSAT media is remain sync and shows UP but site goes down and after passed some hours, the site goes UP automaticaly without doing anything.
Please Help !!30th July 2009 at 13:53 #54802PixGuest
If the VSAT link is “up” while the BTS is rebooting, I would say the problem comes from the BTS itself.
Does it happen regularly ?
And only on one BTS ?
I would check all BTS timers, ensure that they are well sized to take into account the 500ms RTT, and check the BTS Alarms to investigate what caused the BTS down.13th August 2009 at 14:27 #54803loisGuest
OML Means Transmission Issue But There are lot of Issue Related about OML fault.