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28th December 2005 at 07:42 #42763NitinGuest
Well dont have much experience in CDMA I am from core GSM…We have been using filters to minimize the uplink interferce from CDMA. Can someone pls make the specifications for the filter to be used??
Its a band pass filter..but attenuating which range of frequncies25th January 2006 at 04:55 #42764Tommy NguyenGuest
how about the call drop problem of VoIP?
I’m running a Quintum Gateway, and always got call drop to certain region, such as Philippines mobile number. What can I do to improve the quality and stop the problem, anyone got any idea?
Thanks25th January 2006 at 06:52 #42765NitinGuest
I beleive that CDMA operators in India are using EGSM band for their operations. It is recommended to use narrow band filters, covering the band of frequencies that you are using with atleast 90dBc(or better) attenuation of EGSM band frequencies, which can be used in series with your BTS equipment filter. However be aware, such narrow band filters are usually a costly affair.2nd February 2006 at 08:58 #42766AydoGuest
I have a problem about to calculation the Drop Call Rate (DPCR).
I use for calculation a Cell or a BSC this formula:
DPCR = DROP CALL RATIO = 100% * DPC / TCH NORM SEIZURES
But I found another formula for only Cells:
DPCR = DPCR_Cell = TCH DROP-OUT RATIO = 100% * DPC / (TCH NORM SEIZURES + TCH HO SEIZURES)
Which is rigt. I need your support.
Aydo3rd February 2006 at 16:32 #42767BobooGuest
The second is the good one. In the first case you only take into account the commucation started into the cell (the tch normal seizure). But traffic due to incoming call missed. you must add it ( tch ho seizure )
Boboo7th July 2006 at 21:07 #42768ABGuest
What could be the reason of TCH Seizure failures if there was no blocking/congestion reported.
Let’s suppose we have 359 attempts on TCH, 72 call drops, 182 seizures & 177 Seizure fails…
How to avoid 177 seizure fails??8th July 2006 at 00:20 #42769PixGuest
You have three main possible cases for TCH seizures failures:
– Congestion of TCH channels
– Poor radio quality (interference, poor coverage or TRX / Combiner hardware issues)
– Abis link failures / BSC failures
Because you have about 50% failure and you’re saying there is no congestion, I would assume it is probably a hardware issue.
You could check those points first :
– interference (intra-site, intra-cell ?). Try changing the frequencies.
– hardware (reset all TRE. If still failures : lock all TRE except one, and test all the TRE one by one this way. Finally, exhange the combiner…)
– Abis link availability and quality
Note : you have a very high amount of call drops also, isn’t it ?
What is your average call duration ? (= mean holding time)8th July 2006 at 20:53 #42770ABGuest
Yes, call drop is significant.
MHT is around 53s at busy hour.
Also, we have chnaged the hardware but the problem persists. I think ABIS link failure might be the cause? We can also change the frequency but i dont see a C/Ic or C/Ia…18th July 2008 at 09:57 #42771tahir saduzaeiGuest
i want to improve the MPD(minutes per drop) and DCR of whole network. can any of you guide me what to do especially MPD.Any docuement of tips/suggestion is requied on urgent basis. Kindly guide me in this regard. Regards.Tahir13th August 2008 at 00:43 #42772shantiGuest
how to solve worst cluster that have many drop calls?10th January 2009 at 07:59 #42773chiragGuest
please help me because,i m new & entery level for this field
i want to learn about tch drop & congesation,bcch problems and Hand over problems, and how it is related to bts hardware means error occuers to which hardware problame.
my email email@example.com
bye17th February 2009 at 12:20 #42774tankGuest
I have continous value of tch drop in some areas with the value at an average exceeding 3.4 %, the error shown is is that the signal recieved has too amny bad frames, can some please point to me what exactly that indicates??17th February 2009 at 15:19 #42775PixGuest
It’s probably an interference problem.
1/ Does it happen mostly on one TRX, or all TRX ? Which TRX exactly ?
2/ Are you using SFH, BBH or no hopping?5th March 2009 at 09:24 #42776MeenakshiGuest
The call dropping rate for a particular BSC is >3%.
Can it be a problem with Mobile exchange as for all other BSCs there is no such problem found.
Pls. suggest.5th March 2009 at 14:59 #42777PixGuest
Which cells in BSC are having high CDR ?
How many ?
All > check BSC HW failures (boards), or Abis failures, or Ater failures
Some > Abis failures
One > BTS failures