21 minutes ago, NextG said:

Would have been even more useful had you named your router…

D LINK, but not sure of the model. Only about 6 months old.

1 hour ago, bradiston said:

D LINK, but not sure of the model. Only about 6 months old.

Look on the underside to find the model. 
https://www.dlink.co.th/product/dwr-920-n300-4g-lte-router/

 

It has USSD as a menu option. Did you look?

 

 

10 hours ago, NextG said:

Look on the underside to find the model. 
https://www.dlink.co.th/product/dwr-920-n300-4g-lte-router/

 

It has USSD as a menu option. Did you look?

 

 

It's 300 km away from where I am living right now. That's been the main problem all along.

 

The problem involving disconnection appeared to have been solved by the addition of a UPS, but the problem has returned. Even after reset, it disconnects after about 24 hours. I will try to sort it out on my next visit.

 

8 minutes ago, bradiston said:

It's 300 km away from where I am living right now. That's been the main problem all along.

 

The problem involving disconnection appeared to have been solved by the addition of a UPS, but the problem has returned. Even after reset, it disconnects after about 24 hours. I will try to sort it out on my next visit.

The previous reply regarding USSD was not for you ☺️ It was an answer to an issue for another thread entirely. 
Your problem would possibly be solved by the LTE Band lock-in, but I cannot easily find something online that confirms that you can do it with your particular model of router. It can be done on certain models of TP Link routers. In fact they released a firmware update to fix that very issue. AIS would disconnect when the connection was idle. The ability to lock on to any particular LTE Band solved the issue. 

1 minute ago, NextG said:

The previous reply regarding USSD was not for you ☺️ It was an answer to an issue for another thread entirely. 
Your problem would possibly be solved by the LTE Band lock-in, but I cannot easily find something online that confirms that you can do it with your particular model of router. It can be done on certain models of TP Link routers. In fact they released a firmware update to fix that very issue. AIS would disconnect when the connection was idle. The ability to lock on to any particular LTE Band solved the issue. 

Ah, well that sounds highly relevant. It's just odd the connection appeared stable for maybe 6 months after the installation of a UPS. After power outages, it had had difficulty reconnecting. The addition of the UPS appeared to cure that.

 

There are a lot of thunder and lightning storms down there at this time of year. It's possible something's getting knocked over. Yet another variable!