This is not an easy question to answer. Some oncall time is required to be paid and some is not. When trying to determine if you need to be paid while on call, you need to look at your freedom to pursue your own interests while "on call." If you are required to carry a beeper but are free to pursue your own interests, you would not be required to be paid until you had to respond to a call. If you are required to remain at your employer's place of business and are not allowed to pursue your own interests such as reading, visiting with others, listening to the radio, etc., your employer would be required to pay for this oncall time.
Get Help from an Experienced Employment Law Attorney
Have you been discriminated against by a potential or current employer -- as a job applicant or current employee? To best protect your legal rights you should discuss your situation with an employment lawyer. Meet with a local employment attorney sooner rather than later to protect your rights.