- This topic has 26 replies, 1 voice, and was last updated 9 years ago by pix.
5th March 2008 at 04:33 #51279BilalGuest
But SQI statistics don’t depend on number of handovers so there should be no need to adjust the stats for handovers.5th March 2008 at 14:09 #51280PixGuest
Ok I understand your point of view. But I personally still consider a HO as a thing that should be avoided if possible.
In the previous post, I did a typo mistake : read “30” instead of “0”.
Actually, yes, SQI is bad when there is a HO (according to akefa. myself, i really can’t remember)
so the question is whether or not remove bad SQI due to HO or not… In my opinion, no : the HO is a degradation in the voice quality, but for akefa, yes : the SQI shall not reflect poorly a handover.5th March 2008 at 16:07 #51281BilalGuest
yes, HO definitely affects speech quality but does it affect FER?5th March 2008 at 18:20 #51282PixGuest
It’s what I’ve been saying for the past 3 days : There is no speech frame during a handover ! How do you want to compute a frame erasure rate, if there is no frame to look at ? 🙂
A handover = a blank of 40ms to 80ms in the speech.5th March 2008 at 18:43 #51283BilalGuest
Exactly this is the point i wanted to make. HO doesn’t affect FER and SQI stats are totally dependant on FER so?
HO doesn’t impact SQI stats. It is SQI value in TEMS which is impacted by handovers not the SQI stats in the BSS.
I asked the question just to make my point clear 🙂5th March 2008 at 20:49 #51284PixGuest
Ok, it’s clear for me too, now 🙂
The thing is that for Akefa and I, SQI is a metric that belongs to TEMS investigation, and reflects other elements than just FER.
In which BSS have you seen SQI ? Ericsson ? What is the difference between “BSS SQI” and FER ? Is there a linear correlation between the two ?6th March 2008 at 06:06 #51285BilalGuest
Yes, SQI counters are there in Ericsson. I don’t about the exact algorithm but Ericsson documentation says it does consider some radio parameters in addition to FER. The outcome of the algorithms is an SQI that is measured in the MNRU scale dBQ which is an absolute scale for measuring speech quality(ITU-T Recommendation P.810 Modulated Noise Reference Unit ). The output values are from -40 to +50 and the higher value the better speech quality.
SQI values are then divided into the three categories “Good”, “Acceptable” and “Unsatisfactory”. The thresholds that classifies the SQI values into these three categories are 13.5 dBQ and 22.5 dBQ, i.e. everything below 13.5 dBQ is “Unsatisfactory”, everything between 13.5 and 22.5 dBQ is “Acceptable” and everything above 22.5 dBQ is “Good”.6th March 2008 at 08:14 #51286PixGuest
Thanks for these interesting details 🙂 It would be interesting to know the algorithm behind the SQI31st August 2011 at 14:13 #51287DjordjeGuest
Does anybody know exact formula for SQI-MOS computation for WCDMA?7th May 2012 at 12:39 #51288khalilGuest
We have an Ericsson GSM network with 2 media gateway and BSC’s connected to both.I wonder if it’s possible to know by command on the BSC, to which media gateway a ralt2 device (A interface) is connected.
Thanks17th May 2012 at 10:15 #51289DharmendraGuest
Can you pleas tell me what is the relationship between Electrical tilt and VSWR because as i heard ,VSWR reduces as we increases Electrical tilt17th May 2012 at 17:05 #51290pixGuest
i’ve never heard such thing. If there is an effect, then it has to be very small and without any practical benefit.