SFH 1*1 with ALU B10

Hi guys,
maybe it’s not related to what you posted here, but, I wanted to share something regarding DTX in AMR_HR calls. When we have activated DTX for AMR in HR during the call setup we can hear clicks and “metallic” sounds. And this is happening when the calling party is Nokia MS. When we disable DTX it’s fine, but HO due to quality increases. We are using B10 ed7 too. And that’s happening only in WCS call server. In the areas with Legacy there’s no problem. Did you hear something similar to any operator in the world wich has ALU?
Regards,
Rex

rex,

you should disable DL_DTX_AMR parameters (only the AMR related ones, not the “legacy” DTX), as long as there is a problem. I’m surprised that the issue arises with Nokia MS only. The problem comes from the BSS

If your qual HO increases, then the other solution is to disable AMR, in order to all DL DTX for all calls. (that’s probably what I would do 🙂 wait for B11 AMR)

Regards

Hi Ian,
Thanks for your posting! Yes, we are using SFH 1*1 and rxqual was about 0.7 to 0.9 according to NPO RMS indicators. After we activated DTX for AMR, rxqual improved (0.4 to 0.6). But another problem arised as I mentioned in my previous post (click sounds) especially in AMR_HR. Didn’t try with power control yet. Thanks for info regarding TWIN TRX and TFO. We’ll check it and see if it has any impact in our network.
Because the management wants to keep good quality, we have to focuse on that how to eliminate click sounds. By the way, did you hear about or are you using MC_TRX (Multi Carrier TRX)? What’s their pros and cons? I’m asking that in order to replace TWINs with MC_TRXs.
Thanks again!
Regards,
Rex

Hi Ian,
Thanks! We are using B10 Ed07. We’ll wait for B11 and see many changes that B11 offers (among the others Paging Coordination is very interesting). The quality in a network level is good (except in cell level in some areas with high external interference which cause foreign operators) and that’s maybe because we have 29 channels used for hopping. But, that situation will not last to long till Regulation Authority will take from us a considerable frequency band and give it to maybe new operator in the future.
Level of HO and PWR_CTRL are in default parameters. We’ll try and make some tests also with values that Pix recommended.
Regards,
Rex

Hi Mic

What version are you using ? we are in B10Ed02

1. Are you using DTX+AMR now.

only DTX_UL, no DTX_DL

–> we discovered some sites still using DTX_DL ! (eventhough parameters are disable@BSC)

2. If not then did you disabled both UL & DL DTX?

only DL_DTX (but there is also a pb with TFO+Twin+UL_DTX)

3. After Disabling what impact you found in KPI’s(DROP/HO/Qual)??

A raise in DL_Qual of about 10%, no impact on DC or HO, of course this is depending on the quality of your frequency planning

4.What trials you did to prove DTX+AMR did’nt work together in B10..

This is well know by any TAC ! (once again it depends on your BSS version) but you can set up a K18 traces

BR
Ian

Hi Ian,

Intrestingly, I am using B10 ED07,But no Problem found till now with DTX DL & AMR HR..

How you come to define this problem??

Hi Aakriti,

By the way, we noticed one thing when DL_DTX is disabled@BSC, when AMR_HR is disabled, DTX is not triggered.

When DL_DTX is disabled@BSC, when AMR_HR is enabled, DTX is still triggered ! try it !

BR
Ian

HI Aakriti ,

Using DTX_DL and AMR_HR are not compatible with ALU B10, no more bad call and bad quality, of course it will trigger more interferences but we are awaiting for B11 to put back the DTX, according to TAC, the problem siolved in B11.

BR
Ian