The method for maximizing an unavailability interval includes the steps of initializing the starting frame number of each power saving class fi to 1 and adjusting fi to fi′ when the least common multiple of m1, m2, . . . , mi−1 and mi is not relatively prime. The index i is an integer from 1 to t, mi is the sleep cycle of the ith power saving class, and fi′ is an integer that maximizes common sleep windows of the i power saving classes. The common sleep windows of the t power saving classes are then set as the maximum unavailability interval of the wireless telecommunication device.