Coverage Hole in LTE counter

Hi Experts
What is the definition of coverage hole in LTE counter?
Vendor is Samsung.

There is a counter coveragehole in family mro rlf classification, which tells the number of rlf/ho failures due to coverage hole.

Huawei also has those counters related to Ho too early or too late that generates RLF.

Are you using LSM-R?

Yes, lately started using it.