- This topic has 3 replies, 1 voice, and was last updated 11 years, 4 months ago by pix.
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26th November 2012 at 14:08 #68740HendrikGuest
Hej,
I have got a question concerning DTX in UL/DL.I did some measurements with a mobile phone in a GSM network and took a look at the measurement reports. I often got weird results for RXQUAL before a handover took place. The RXQUAL-values were 0 for quite a long time and than suddenly fell to 7. It looked like this 0-0-0-0-0-0-0-7-7-handover.
These values are the RXQUAL_sub values. However, I dodn’t know wheter DL DTX is turned on.My question no is whether UL DTX could affect the measurement of DL RXQUAL. Actually, this should not be the case but I am asking to be sure.
Thank you very much for your support.
/Hendrik
26th November 2012 at 19:26 #68741pixGuesthi hendrik,
UL DTX cannot affect DL Quality (sub or full)
DL DTX affect DL Quality full but not DL Quality Sub.Are the two last measurements show rxqual dl = 7 ?
Is it more than 2 measurements or less ?I would say that the Bad Quality in DL caused the HO to be triggered. Is the HO COMMAND (layer 3) is received before the QUAL=7 or after ?
Please check your Qos stats : HO DL Quality Rate. Is it high ? (> 30%)
Are there a lot of drops ?
a drive test mobile would actually give you more than the rxqual : it will also show the BER. If you can find it, then what’s its value ?
Cheers
pix27th November 2012 at 09:28 #68742HendrikGuestHi Pix,
thank you very much for your support. I got a lot situations where the quality was like this 0-0-0-0-0-0-0-0-7-7-handover-0-0 (values of RXQUAL sub).
However, when I use the RXQUAL_full values (which I have to if DTX DL is disabled), the values are, e.g. 2-3-2-1-handover-2-2-2-0-0 which I can explain.The handover command came before the bad RXQUAL values. I don’t know why I haven’t had a look at this earlier…
It seems that my evaluation software or the phone does soem strange things since the serving cell changes tree measurement reports after the HANDOVER COMPLETE message.Unfortunately, I have to rely on a “normal” phone. Thus, I cannot provide any BERs.
Thank you very much again! I just wanted to make sure that I don’t have any wrong ideas.
/Hendrik
27th November 2012 at 19:20 #68743pixGuest“The handover command came before the bad RXQUAL values. ”
ok, that’s the key. I notice this kind of behaviour too, and there’s nothing wrong with it.
Right after a HO CMD, the MS is not listening to the serving cell anymore, so measurements are not valid.
So problem closed 🙂
Cheers
pix -
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