Some people have got a problems with a speed/bandwidth when they loose CA connection, and they must do some action like disable disabled Cell Lock or setup CellLock when they have got CL because that action is fast, recovery connection is fast and CA back to work.
And they do own scripting to detect and do some action.
I can only share my scripts who detect no internet and that way you can do any action who is at your option the fastest.
Simple watchdog: http://forum.mikrotik.com/t/sxt-lte-4g-cat6/134468/1
Advance watchdog: http://forum.mikrotik.com/t/tx-rx-fp-rx-dropped-pppoe-account/132656/1