Methods and devices for determining intervals between mobile device network searches use measured signal power as lookup criteria to obtain a predefined “sleep” duration from a sleep duration data structure. When a network connection is lost the mobile device may compare received signal power to criteria in a data table to determine an appropriate sleep duration during which the receiver is de-energized to conserve battery power. The sleep durations vs. signal power may be predefined to provide performance as good as other sleep duration determining algorithms while providing flexibility for matching network coverage characteristics. An appropriate sleep duration data table for use may be determined based upon device location or user inputs. At the end of a sleep interval, received signal power may be compared to a threshold to determine whether the receiver should return to sleep mode or attempt a network connection.