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the-modem-distro / pinephone_modem_sdk

Pinephone Modem SDK: Tools to build your own bootloader, kernel and rootfs
GNU General Public License v3.0
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Modem switches from 4G to 3G during a phone call, can't have a phone call over 4G at all :-( #182

Open merinfor2021 opened 1 year ago

merinfor2021 commented 1 year ago

When I initiate a phone call, my modem auto-switches from 4G to 3G - despite my 3G, 4G (Preferred) setting for Network Mode . That's a significant issue for me, because in some areas 4G signal is much better than 3G. If the 3G network is unavailable, or I change my Network Mode setting to 4G only - I won't be able to initiate a phone call at all, just get an instant "Call ended".

Similar situation if I receive a phone call: despite I'm on 4G, when the modem sees a phone call is incoming - it auto-switches to 3G. Please, could you help me?

Hardware: Pinephone 1.2 with Quectel EG25-G Firmware: 0.7.1 , but had it on 0.6.8 too and didn't try the earlier firmwares ADSP version: 30.006.30.006 (I did a full EDL installation - moreover, never had any installation error during these switches) Distro: PostmarketOS with the latest upgrades (because no SystemD) Frequencies: 3G - 2100MHz (Band 1), 4G - 800 MHz (Band 20) / 1800 MHz (Band 3) / 2600 MHz (Band 7)

Biktorgj commented 1 year ago

Modem is unable to negotiate IMS (VoLTE) with your carrier, so it falls back to 3G when doing a call because it's not available.

Name of your carrier (and country)?

castenaso commented 1 year ago

Try to check that https://forum.pine64.org/showthread.php?tid=12560 its a way to modify profile and choose the better suited profile for your carrier. If you fail using mmcli because you get a strange error regarding debug mode, use minicom. To use minicom (sudo apk add minicom) after install type: (minicom -w -D /dev/ttyUSB2) [im not sure about letter -D, and im not sure also on right syntax of the command, biktorgj knows well minicom], and if i reported well minicom command you can type mmcli -m any --command... blabla, like written on the link above

Piraty commented 1 year ago

@merinfor2021 check AT+QMBNCFG (https://wiki.pine64.org/wiki/PinePhone#VoLTE ) for an appropriate volte profile and find a peer with phone supporting volte to double-check.