Delayed voice stream when VoLTE is activated on EG25G-GB

IoT Modules LTE Standard Module
1

Hello

with EG25G-GB, firmware EG25GGBR07A08M2G, with operator CellCom (Israel), voice stream is delayed by some seconds when VoLTE is activated.

With VoLTE deactivated, voice call fallback to 3G, everything is ok.

QMBNCFG=“AutoSel”,1

In France, no such issue detected with any operator.

Any idea ?

2

Hi @RadeoCom

I have sent a follow-up email to your email address. Kindly check.

Based on the reported behavior, since the voice call works normally when VoLTE is deactivated and falls back to 3G, the issue may be related to the VoLTE/IMS configuration or the audio path when VoLTE is active.

If the module is connected to an external audio codec rather than using an integrated audio path, the total audio path delay should also be checked, as excessive audio delay can affect voice processing and echo cancellation.

Please try the following troubleshooting steps:

  1. Run:
    AT+QMBNCFG=“list”

    Please check whether a CellCom-specific MBN is activated.

  2. If the CellCom-specific MBN is not available or does not resolve the issue, please try the following configuration:

    AT+QMBNCFG=“SELECT”,“ROW_Generic_3GPP”
    AT+QMBNCFG=“autosel”,0
    AT+QCFG=“ims”,1

  3. Reboot the module:

    AT+CFUN=1,1

  4. After reboot, please test the VoLTE call again.

3

Hello,

I did many tests but still have this delayed voice flow over USB when VoLTE is activated.

We did test all the available MBN in Firmware EG25GGBR07A08M2, including “ROW_Generic_3GPP” of course. Still face the issue.

Is there a firmware more recent to test ? May I have the latest one ?

Best regards