Parameters to reduce VoLTE audio gap

4G LTE
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1

Hi Experts,

What is the difference between RSSI and RTWP?

Also: by changing pdcchCqishift -5 to -2, ilReacTimerUl 5ms to 500ms, p0NomPusch -82 to -87, ulpcUplevSch -88 to -94 and p0NomPucch -114 to -111. SINR and MCS coding improved but UL BLER degraded, Retransmission increased, UL throughput degraded, RTWP increased.
Any idea for degradation?

Goal is to reduce VoLTE audio gap.
Vendor is Nokia.

2

All these parameters have different impact eg by changing pdcchchishift we are giving less offset to the received cqi value and by this change cqi value will improve and pddch cce utilization and cce agg 8 level will reduce thus giving improvement to overall capacity and throughput.

3

What will be the impact of changing Ponompucch/pusch?
Is it better to keep lower value?

4

Increasing ponompucch will improve pucch decode SR but can impact interference.
In above mentioned scenario ponompusch power is reduced which will compensate the uplink interference.

5

But that also depends upon type of scheduler being used either interference aware or channel aware.

6

Can one possibly increase phnompucch and reduce ponompusch at the same time?
I think this is wrong. Can someone correct me if am wrong?

7

Hi Experts.
Any idea to mittigate audio gap in VoLTE?

1 Like
8

From radio side it can be due to poor radio condition, larger handover execution time etc.
From transmission side packet loss can be found.
If still no issue found, you need to collect wiresherk trace to check if there is any issue in SIP protocol related signalling.

9

On parameter side, is there any parameters that could be tweaked?

10

Activate TTI bundling and RLC segmentation.

11

Does rlcSength, pdcpSNLength and rlcmode could help? Will optimize?

12

In my personal experience, not so much.
But worth getting others opinions…

1 Like
13

I agree with this. :+1:

14

Thank you experts…

15

Normally as per our experience when UL is weak or DL RSRQ is poor then you ll have audio gaps.
We resolved our complaints by enabing RSRQ based Handovers for VoLTE.

16

It is recommended to enable tti bundling for Volte as voice requires contiguous data flow unlike internet.
Packet loss or jitter in the backhaul may also be verified.

17

Thank you for answers and experience sharing. :slight_smile: .

18

Usually for MBB the trigger quality is RSRP. Do you have the flexibility to change the trigger quality to RSRQ for QCI-1(VoLTE) only? or you just applied the RSRQ related offsets for target thresholds for QCI-1(VoLTE) bearers making sure the target has good enough quality(RSRQ)?