- This topic has 10 replies, 1 voice, and was last updated 12 years, 3 months ago by taqi.
7th August 2008 at 15:08 #53458FloGuest
I’m facing serious issue with MS Nokia only & during 900 FR AMR call (N95, N6880, etc). After a couple of time the interlocutor hear a wistling noise and has to hang up.
Abis & TRX traces shows that UL whistling noise come during AMR codec adaptation just after silent SID frames. AMR deactivation solve the pb.
DTX UL is disable at cell level but MS use it lawlessly.
My question is does anyone faced such pb with other vendor than Alcatel and is a solution exist with keeping AMR enable ?
tx & BR7th August 2008 at 16:31 #53459MicheleGuest
what is the hardware equipment? Furthermore, have you checked the System Information content (about the UL DTX, SI6(you need a TEMS to check it))? Are they compliant with the disabling of UL DTX?
On the contrary Network believes to not performing UL DTX, while MS performs it.
Is TFO (Tandem Free Operation) enabled?8th August 2008 at 09:28 #53460FloGuest
It’s BSC mx and G4 BTS. The new SI6 contains DTX_Indicator = “MS shall use uplink discontinuous transmission” whereas DTX_INDICATOR_FR_AMR is set to msShallNotUseDTxAMR …
TFO is disable.
BR,28th August 2008 at 14:14 #53461MicheleGuest
so it seems that MS behavior is compliant to SI6 and BSS sends an erroneous information about UL DTX to MS in SI6.
The consequence is that probably BSS takes into account erroneously SUB/FULL measurements in Measurement Results received by MS, while performing Power Control and Handover algorithms…8th September 2008 at 20:56 #53462VictorGuest
For AMR implementation, Nokia recommends:
1.- DL DTX should be Active in BSC (DOWNLINK DTX… YES)
2.- DL DTX should be turnned off in ET-PCM from TCSM.
3.- DL DTX should be OFF in MSC side in each cell (DOWNLINK DTX DISABLED BY MSC ….OFF)
I hope this helps you.
BR27th November 2008 at 11:06 #53463TAQIGuest
WHAT IS THE BEHAVIOUR OF THE NETWORK WHEN DTX GOES ON FROM OFF STATUS.WHAT THE IMPACT OF DTX ON NETWORK?SPEACIALLY IN RXQUAL AND C/I27th November 2008 at 14:43 #53464rf fanGuest
We have the same problem in Alcatel27th November 2008 at 15:01 #53465pixGuest
it looks like AMR and DL DTX are not compatible? i’ll check it out.27th November 2008 at 15:28 #53466rf fanGuest
The problem appear only with some Nokia Symbian phones (subjectivity from my point of view at the moment). At this stage I haven’t any proved arguments. There isn’t RMS problems and nothing from radio interface only ….27th November 2008 at 21:03 #53467rf fanGuest
Pix, amr and UL dtx28th November 2008 at 07:53 #53468taqiGuest
what is the value of dtx when called party keeps silent?
if calling party countinueous transmiting.(calling party connected with tems investigation for dtx investigation.)