Unable to reconnect the mobile broadband, if signal drops for more than 3 hours

Hi,

I am working on Ubuntu 16.04 with Telit module for mobile broadband. I am facing the problem in reconnecting the mobile broadband once it lost the connection more than 3 hours.

I was able to use the mobile broadband until there is signal drop.If signal drop occurs for a long period(more than 3 hours, it is varying at times), mobile broadband is unable to re-establish the connection.As I have selected auto connect option in the Mobile broadband connection GUI, it is reconnecting if signal drop is less than 2-3 hours

When I checked the system logs, I found that Network manager is trying to reconnect for some time, if it is not succeed in reconnecting it is signalling modem manager to kill the pppd daemon and switch to simple connect rather than using pppd. Apart from it is removing some other modules.

I tried with restarting network manager, modem manager and pppd daemon from systemctl but nothing worked, Can any one suggest the solution to fix my problem.

I have posted the same query forum, for detailed syslog, please refer to the below thread.

https://ubuntuforums.org/showthread.php?t=2396588

Regards,
Naveen.