I am so happy of my PinePhone, but there is one particular issue that significantly decreased its usability: connection to the GSM mobile network. Fortunately, with some simple tweaks to NetworkManager it is possible to make this operation much faster.

The problem I experienced is that the PinePhone (PP) is rather slow in connecting to GSM and, to a much lesser extent, WiFi, after the phone comes out of standby. The delay for WiFi occurs more strongly in PostmarketOS, while Arch-based distros such as dreemurrs’s and Manjaro are fast enough not to cause problems. Let me clarify that even on pmOS is not such a big problem, perhaps it takes 6 seconds instead of 3 (that’s what I feel without actually timing it), but it is enough to be noticeable. There’s an issue about that1 so people are aware of this and it will be fixed one day.

The situation for GSM connection is really not so good, however. As a disclaimer, I am running the default modem firmware that shipped with the PP, and I don’t know how Biktorgj’s firmware fares in this regard. Secondly, I am using a foreign SIM card (always within the EU), thus the delay I experience may be related to roaming.

So there are actually two issues with the modem: first, it frequently dies when the phone wakes up from standby, which causes a 30-or-so seconds delay before it comes up again. Second, searching for a mobile operator to connect to also takes 30 or so seconds if not more. The first issue seems to be again related to pmOS, while I suspect the second problem is due to roaming.

We can skip the search phase by forcing the modem to connect to an operator of our choice. To do this, we first do a scan to see all available operators, then connect to one of our choice:

> # first, get the modem number
> mmcli -L
    /org/freedesktop/ModemManager1/Modem/0 [QUALCOMM INCORPORATED] QUECTEL Mobile Broadband Module
>
> # scan available networks, large timeout because it's slow (but not that slow)
> mmcli --3gpp-scan -m 0 --timeout 900

  ---------------------
  3GPP scan | networks: 26202 - Vodafone (gsm, available)
            |           26203 - o2 - de (lte, available)
            |           26201 - TDG (gsm, available)
            |           26202 - Vodafone (lte, available)
            |           26201 - TDG (lte, current)
            |           26203 - o2 - de (gsm, available)
>
> # to connecto to another operator we need to disconnect first
> mmcli -m 0 --disable && \
    mmcli -m 0 --enable && \
    mmcli -m 0 --3gpp-register-in-operator 26201
successfully disabled the modem
successfully enabled the modem
successfully registered the modem

I tried several and found that TDG worked best, while o2 did not let me navigate at all. At first I put these commands in a script that I ran every other time I unlocked the phone, but there’s actually a better way to do this via nmcli:

> sudo nmcli connection modify coopi gsm.network-id 26201

This will essentially force a connection to that operator automatically without manual intervention. The connection coopi is named after the APN profile in the settings. Something that I haven’t managed to test yet is what happens when this operator is not found, e.g. when traveling. Another setting that I found useful was the automatic connection:

> sudo nmcli connection modify coopi connection.autoconnect yes

I found this to be off some time ago, perhaps in KDE but I don’t remember exactly. And finally enable roaming (fundamental in my case):

> sudo nmcli connection modify coopi gsm.home-only no

I haven’t had any more delays or problems with these three commands on Manjaro, which I think I will be driving for some time after extensively using pmOS.

  1. https://gitlab.com/postmarketOS/pmaports/-/issues/973 ↩