- This topic has 30 replies, 1 voice, and was last updated 13 years, 5 months ago by Pix.
14th November 2006 at 22:53 #46133sammiGuest
Drop are due to unsuccessful Intracell handovers due to loss of connection (MS). I even increased Radio Link Timeout from 9-15 but i dont see any improvement. Is there anything you can suggest me? Do u need any other info.
Sammi15th November 2006 at 06:30 #46134pixGuest
well.. you really need to see on which TRX is the issue, because right now looking globally at the cell doesn’t seem to be enough.
did you clear out all the possible interferences ?
did you check your intracell HO settings ? what are the triggers ?
Loss of connection might be due to TRX failures. The failure is sudden, leading to the expiry of the radio link counter whichever its value…16th November 2006 at 07:33 #46135DaraGuest
Who can tell me what is the main problem for poor sound? and high drop BSS?19th December 2006 at 18:52 #46136MarcelGuest
that would be bad level and or bad qual, or good level and bad qual. Perform drive test or spectrum measurement29th June 2007 at 17:29 #46137akefaGuest
In the baseband hopping the call is carried by all the TRXs of the sector. They togather will hold the call one after one in a systematical way and constabt order. It is a big mistake to say the most traffic is carried by the last TRX !! did you forgit the hopping ?30th June 2007 at 00:10 #46138nikkyGuest
I am suggesting three ways here
1) chk the uplink volume and downlink volume.it shd be 4DB.
2)then also check the TRAUs in the Aif card
3)and check the companding law algoritham which u are using(mu law or Alaw).we shd use same algoritham in the entire network
Nikky1st July 2007 at 18:16 #46139PixGuest
It depends how the hopping is implemented. In Alcatel, the hopping (sfh or bbh) is “synthetized”, meaning that the call is on one TRX, but the frequencies are hopping.2nd July 2007 at 06:41 #46140NitinGuest
It means if their is a problem or interferance in a specific time slot, then call will be drop everytime & intracell handover is not possible?? Resulting will increase the Drop rates..2nd July 2007 at 10:11 #46141PixGuest
Yes. It also means that a call a on TRX which is faulty will not be “saved” by hopping.
It is actually good, because the optimizers can detect a faulty TRX quickly, even with hopping !
Increase in call drop rate, but fast reactivity from optim team… that’s a trade-off.
The other solution (hopping on TS) will decrease call drops, but it will degrade the voice quality, and make the detection of the HW problem much slower. Altogether, subscribers are less happy with the second choice (bad quality for one year is worse than high call drop for 2 days)2nd July 2007 at 10:40 #46142NitinGuest
You said that TRX is faulty in that case, but i had also heard that some times a Time slot is faulty & some times it enters in to Not used state. But time slot is just a span of time,difined for a user to make a call in a particular time.So how it will be faulty?????2nd July 2007 at 11:39 #46143PixGuest
timeslot are rarely not-useable… Actually, let’s say that i’ve never seen that myself. Usually, it is the whole TRX that is faulty.
But i guess the case can happen.
How can it happen ? Well, maybe some misconf between Abis and Air interfaces, or some software failures in the cell..?2nd July 2007 at 22:24 #46144constantinGuest
First you must realize that if the cell is omni,and has 4 trx
surely it is at full capacity.
when you block 1 trx its reduced capacity to the cell,in this case these are not dropped calls because the calls do not establish a connection and send you to voicemail,for lack of resources.2nd July 2007 at 23:00 #46145KalboNaSaRFGuest
Sammi, is the extended cell Nokia or something else. Implementation of extended cell as far as I know is different for Ericsson and Nokia. Nokia requires to have at least 2 TRX, one Normal TRX for distances 35km. For Ericsson you need only one TRX, but can only support 4 users.
Nokia scenario – If you block the E-TRX and have only one E-TRX, you lose your target TRX for intracell HO when TA upper threshold is triggered.
Ericsson – blocking a non BCCH TRX should not affect intracell HO, since coverage is not affected. Only capacity.
Your site might be configured as 3 N-TRX and one E-TRX, if this is the case, if you want to service the E-TRX, reconfig it for 2N-TRX 1E-TRX.3rd July 2007 at 08:51 #46146NitinGuest
I had seen these cases. when you create a new site, sometimes timeslotes enter in to the not used state. You have to just create these time slots again.10th November 2007 at 10:12 #46147ArpanGuest
U hav written in one of ur answers that..
“The last trx of the cell is usually the one that carries the highest amount of traffic.” Can u
pls clearify that what is the reason for that????