My Google Nexus 4 with Lollipop 5.0.1 has lost its signal and rebooting does not bring it back, how do I fix this?

[AC Question]

My google nexus 4 with lollipop 5.0.1 has lost its signal and rebooting does not bring it back

It has not been used for 10 days due to international trip, but while international tried another SIM in it to no evail