Some kind of remote access to the device is mandatory, to downgrade device firmware.
It can be:
- Public IP
- VPN
- RMS (Remote management system, for more details check here)
If your device has not been added to RMS before, you can try the platform, as each new device gets a month to use the platform for free.
To get WiFi status, a custom SMS would be required, which would execute a custom script. An example of a script is as follows:
#!/bin/ash
TEXT=$(ubus call network.wireless status | grep "\bup\b")
gsmctl -S -s "0037060000000 $TEXT"
where 0037060000000 would have to be replaced with a number to send SMS to. It would return whether the interface is running (up:true) or stopped (up:false). However, to configure the rule, access to the device is needed.
Best regards,