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AMR & DTX : MS Nokia whistlinge

  • This topic has 10 replies, 1 voice, and was last updated 16 years ago by taqi.
Viewing 11 posts - 1 through 11 (of 11 total)
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  • 7th August 2008 at 15:08 #53458
    Flo
    Guest

    Hi guys,

    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 & BR

    7th August 2008 at 16:31 #53459
    Michele
    Guest

    Hi Flo,
    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 #53460
    Flo
    Guest

    Hi michele,

    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 #53461
    Michele
    Guest

    Hi Flo,
    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 #53462
    Victor
    Guest

    Hi Flo
    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.

    BR

    27th November 2008 at 11:06 #53463
    TAQI
    Guest

    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/I

    27th November 2008 at 14:43 #53464
    rf fan
    Guest

    We have the same problem in Alcatel

    27th November 2008 at 15:01 #53465
    pix
    Guest

    rf fan,
    it looks like AMR and DL DTX are not compatible? i’ll check it out.

    27th November 2008 at 15:28 #53466
    rf fan
    Guest

    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 #53467
    rf fan
    Guest

    Pix, amr and UL dtx

    28th November 2008 at 07:53 #53468
    taqi
    Guest

    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.)

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