LTE modem doesn’t work

I installed (as described in official documentation) LTE modem from LTE pack (QuecTel ET20 - never been used before) on USB3 to new Turris Omnia. After installation it worked till first reboot. From this time I was successful two or three times to get connection (T-Mobile CZ) to the internet, but don’t know why.
After factory reset it worked again till first reboot.
Any idea what happened? It doesn’t look like HE issue.
Thanx in advance.

Welcome to the Lte problems club.
After many years of experience with TO Lte, here is my advise if you wish to keep this buggy modem.

  1. Ask cz.nic team to provide newer firmware for the modem. @Pepe Quectel does not respond back to emails for newer firmware, could cz.nic team ask for it?
  2. Use qmi cellular to set the interface rather than what is described in official documentation
  3. Set your modem to use only LTE or 3g or gsm and look at the signal:
    To set lte only use the command below:
    uqmi -d /dev/cdc-wdm0 --set-network-modes lte
    To see the signal quality the command is:
    uqmi -d /dev/cdc-wdm0 --get-signal-info
    Based on your tests, select the best signal LTE or 3g (or even gsm if you need stability)
  4. Install watchcat and set it up to reboot the router if there is no internet (though this might not work most of the times)
  5. Install usbreset, find your usb modem (something like Bus 001 Device 002: ID 05xx:92xx Qualcomm, Inc. Acer Gobi 2000 Wireless Modem ) using lsusb and issue:
    usbreset 05xx:92xx when the modem hangs.
  6. In the unlike case that usbreset does not do the job your final two options are:
    6.1 Use AT command to reset it: echo -e "AT+CFUN=1,1" > /dev/ttyUSB2
    6.2 Power cycle the router

since version 0.99 I have had some minor problems with lte. I wrote various correction scripts to solve the problems. Your problem after restarting the modem was one of several. This problem I fixed with ifdown and ifup interface of LTE after modem reboot. But after the last fw I did a factory reset. I did All setings again and all problems with the LTE disappeared even without correction scripts. Sure I don’t know what is diferent about LTE from old versions to new. But problems wit LTE are individual and I made repairs individually for different devices and situations. Examples AT commands for reset was not working everytime.


thanks a lot for all tips. To be honest, I did not test them all yet. I do not have this Omnia at home, so try different changes takes a long time.
I have following experience: after boot LTE modem is not connected, but if I leave it long time (e.g. overnight), it connects somehow and stays connected for few days and few gigabytes of data. But if I reboot or connection is lost, it takes unpredictable time to connect again. And seccond issue is connection speed, which is aproximately half of speed on iPhone in same place and same mobile operator.
I have to use it as primary internet connection there. I need stable connection and as-fast-as-possible speed here.
Does it makes sense to replace old QuecTel ET20 with new QuecTel EC25 or external modem like Huawei E3372h or it will be the same as with old one?
Thanx a lot in advance,

I am on Turris OS 4 for a week now. I had to reset the modem after the upgrade of TO.
After that, EC20 seems to be working flawlessly using qmi-wwan.
Reset instruction are available at the troubleshooting section of this page:
Regarding speed, you might need to connect an external antenna

Thank you very much. I’ll try Turris OS 4 tomorrow. I have antenna MikroTik MTAO-LTE-5D-SQ (, so I expect that it should work good.

Hello all,
Quectel provide the firmware packages on ask basis on their support forum.
See this post.

The tool for flashing (Qflash) can be obtained here

Not true. For hardware included in turris omnia (check your ATI with echo -e 'ATI' > /dev/ttyUSB2) you have to email the support and then they come back with questions of your project, your provider, were did you buy, how many pieces will you buy … and they never send the firmware.
It would be good it Turris team could obtain the firmware and provide it to the turris omnia owners.

Hi Lampra
I’m stucked with my EC25-E. Just doesn’t want to work stable neither via QMI or Serial port. ncm or mbim - no chance at all. Probably an expert would fix it but to me it looks pretty tricky. Finally it’s not what you expect buying $500-value hardware)

But I suppose the issue more about the EC25 modem. Could you recommend any LTE modem that just works out of the box without heavy R&D work? Just plug&play?

Hi Mike,

I am familiar just with EC20. I am not sure if you could succeed plug & play with any PCIe modem on TO.
For almost plug & play, though not tested by me, I personally would go for a mikrotik LtAP or wAP or LHG or SXT depending on your needs.

I was close mentally to buy on of mikrotiks lte product but yesterday tried to bring up GL MiFi router with EC25. And it just works, right away from the UI, no Luci or console. Just work and very stable.

Do you think it’s possible to make a backup from Luci and upload it to TO?

I saw in an other post that you have TO5 installed which is not stable so maybe your problem is not the modem.
I would suggest to install TO4 for the moment.
Then, as I experienced problems also with the sim cad, first you need to check the sim card in turris omnia. I had to put some plastic tape to hold it down.
Then, Install the modem and the protocol extensions as described in the documentation and test it.

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I am now on TO 5.0.1 and Lte interface complains that “sim is not initialized” after boot using qmi cellular to set the interface.
A workaround that seems to work so far is to stop the interface and reset the modem.
I use the following in rc.local
(sleep 60 && ifdown Lte && /root/ && sleep 60 && ifup Lte) &

And this is the reset script:

root@turris:~# cat 
echo -e "AT+CFUN=1,1" > /dev/ttyUSB2

just for reference this issue i usually caused by the sim card getting powered off. usually you can power it on using:

qmicli -d /dev/cdc-wdm0 --uim-sim-power-on=1