Hi Norbert, Aleksander, > > Giacinto, added you in CC, in case you have some suggestion.
don't worry, I am following MM, libMbim, libQmi. > > > > > We're using a Cinterion ELS61-E R2 and seem to suffer from a lot of > > "packet data disconnects" and cell/rat/MO switching. Are you using the bare modem or on some datacard? Is the power supply good? And the antenna? Please ask your contact in Thales (or a reseller) if there is a more recent FW for your modem. (I am part of Thales, too, but I am not deep into ELS61 and all its variants and options, so it would take more time to me to find out than for a more direct contact). These would be the main things to look at, to understand and fix the root cause, the rest below (in which I am going to comment anyway), could be workarounds for special situations, but not the solution. > > We're advised to force the modem to use 3G/2G (or 4G/2G) Radio Access > > Technology with the AT^SXRAT command. MM doesn't use (as of today) this command, so you are guaranteed that the modem will remember the settings. AT^SXRAT allows to set up to 3 preferences, which can also be combined. I haven't tested on ELS61, but PLS62 should be the same. > > We've been told the "AT+COPS=0" may reset SXRAT settings. I have checked on the ATC, and indeed AT+COPS=,,,x (or AT+COPS=0) will change the preferences, as well as AT^SXRAT, and the last-sent will define the behavior. > > > > I've tried to do this via: > > mmcli -m 0 --set-allowed-modes='2g|4g' --set-preferred-mode='4g' > > > > but it doesn't work and even if it would, I'm not sure this means the > > "AT^SXRAT" command alwaysf ollows "AT+COPS=0" nicely. > > > > I see no "AT^SXRAT" in the source code, so I guess "AT^SXRAT" is a > > Cinterion specific command that isn't supported yet. > > > > I do like to use the "AT^SXRAT" command. > > > > So I'd like to do a "AT^SXRAT" after each "AT+COPS=0". This involves > > changing modem_3gpp_register_in_network, is this the right thing to do? > > > > If not, how to best use the "AT^SXRAT" command? > > > > The Cinterion plugin currently uses AT+COPS also to configure access > technology; e.g. if 4G-only is requested, we would run AT+COPS=,,,7 > > Does this COPS based logic to configure access tech not work in the > ELS61? Is ^SXRAT the only way to do that in the ELS61? If ^SXRAT is > the only way to do it, we could upgrade the Cinterion plugin to use > it. But I'm not sure that sending the SXRAT after each COPS would make > much sense; is there no other way to do that? > > Also, if COPS=0 resets the desired access tech, I wonder if the same > is currently happening with our already available COPS based access > tech selection logic. AT^SXRAT could be used for Intel chipsets (ELS61, PLS62, ...), instead of the AT^SCFG="Radio/Band..." commands and/or AT+COPS=,,,x (and so in the --set-allowed-modes command) However AT+COPS=0 might be sent at startup if the modem reports +COPS: 2, and in this case it will start the registration/attach, but also reset the preferred technologies. I don't really agree to append AT^SXRAT to AT+COPS, that would make the modem search twice in most of the cases, and I know that it is particularly slow on this chipset under some conditions. And so it would maybe solve a specific problem, but introduce others. If you want a single tech, a better solution would be to track that in the code where AT+COPS=0 is sent and use AT+COPS=0,,,x instead. Best Regards, Giacinto _______________________________________________ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
