- This topic has 21 replies, 1 voice, and was last updated 7 years ago by S K SAURABH.
7th July 2005 at 16:22 #41709govindarajGuest
In nokia bsc 3i (Dx200) we are getting severe call drop . in ZAHO command i am gettting this type of problem. Even chnage of trx, BB2F ,Recreate the pariticular bts every thing done.but stiil no improvement.
the alarm is
2993 BTS AND TC UNSYNCHRONIZATION CLEAR CALLS ON ABIS INTERFACE
Any nokia experts pls help me .8th July 2005 at 16:12 #41710PatrickGuest
When ATER or ABIS cut off, you can have this alarm.
extract of NED:
Calls have been cleared three successive times on the same Abis interface
channel due to BTS and transcoder unsynchronisation.
Supplementary information fields
1 identifier of the base station
2 identifier of the TRX
3 identifier of the radio time slot
4 number of external PCM circuit
5 time slot of external PCM circuit
6 sub-time-slot of external PCM circuit
Lock the channel in question with the MML command ERS.
Check the transmission between the BTS and the BSC (and transcoder).
Check other active alarms concerning the BTS and the BSC
(and transcoder) transmission or transcoder plug-in units.
Correct the faults causing the alarms.
When the above-mentioned transmission alarms have been cancelled
or when transmission is working again, unlock the channel in
question with the MML command ERS.11th July 2005 at 07:16 #41711selvaGuest
if you block the particular time slot it will be solved.11th July 2005 at 08:39 #41712alexanderGuest
or check your transmission, may be it’s not ok, may be some timeslots are overlapping
http://www.dx200.biz7th August 2005 at 12:15 #41713govindarajGuest
I am Govindaraj . For the above said problem was cleared by setting the BTS clock (DAC value) with normal value like 2051.
But i don’t know why the BTS(Ultra) clock value is drastically decreasing. ?????
if any one have same type of problem and if u have a solution pls share with me.8th August 2005 at 03:33 #41714SurvivorNBSGuest
Try to replace the BOIx9th August 2005 at 14:54 #41715alexanderGuest
govindaraj, did you solve the 2993 alarm problem?
http://www.dx200.biz9th August 2005 at 17:43 #41716govindarajGuest
Hi Alex and SurvivorNBS,
Thanks for u r reply.
To Alex : Yes alex we had solved the problem by recommissioning the site than it was cleared.our nokia local support engineer told thatwas problem due to clock.
To SurvivorNBS : Actually not only in that site every sites we are facing the clock value is reducing .
So that way i send this to all of u.
Govindaraj27th August 2005 at 10:30 #41717hoistler45Guest
After recommissioning the affected sites?where there signs of the clock value decreasing again after a few days?
hoistler27th August 2005 at 21:12 #41718GovindarajGuest
please check the BTS properties log , there u can see clock value which is different with u r installation clock value.
Govindaraj.M7th September 2005 at 10:07 #41719nicaGuest
aside from the BSC, is there any equipment between the BTS and TC? If you are using NOKia Flexihopper as the trs medium, try to upgrade the SW of the FH. Check also the parameters of all your transmission equipment i.e. the CRC. Check also the integrity of your clock source.9th September 2005 at 17:49 #41720GovindarajGuest
I feel this alarm came due to the problem of clock source in BIO card . And one more think thia alarm cames mainly in TSDA only.
Govindaraj11th September 2005 at 04:08 #41721OliverGuest
You should verify the quality of your transport network between BSC and BTS. Is it a PDH or SDH, consider that BTS uses abis PCM to extract the clock but if you are using SDH you need to verify the clock reference for SDH network, it should be stratum 1.
Also in PDH, Nokia recommends not to put more than 5 BTS’s into a chain.
Finally, in new year eve we got many 2993 alarms. The problem was related to a severe radio control channels congestion under the coverage of one BSC which caused stop traffic in many BTS. It seems to be a SW bug still under study.
BR31st July 2006 at 14:23 #41722AMRGuest
Did you really clear 2993 problem or is this still happening?
Please give advice if you did clear problem
AMR6th August 2006 at 11:49 #41723RahulGuest
can u further explain SDH and PDH what r these and what r there roles in transmission