On-call pay comparisons

I would love feedback on what kind of guidelines are out there re: on-call pay in various hospitals. The hospital I'm with are making alot of adjustments to the negative and we are researching others for comparisons. Hourly call pay; minimum amount of hours paid for upon called in; does hourly pay stop when called in; do you have to work a minimum amount of time before getting paid a block of time at time and a half; etc. Any feedback would be most helpful! Thanks