Method and system for maintaining synchronization in low-power mode over a frequency hopping radio link

摘要

Systems and methods for maintaining synchronization of a base unit and a portable unit in a low-power mode are provided. The base unit and the portable unit communicate with each other via wireless frequency hopping radio communications links. The base unit and the portable unit switch to a synchronization state in a synchronization period during the low-power mode. During the synchronization period, the base unit transmits one of a first and a second link synchronization messages. The portable unit is required to respond to the second link synchronization. If the base unit receives a response from the portable unit within a predetermined number of periods, the base unit and the portable unit switch back to the low-power mode. Otherwise, the base unit and the portable unit are switched to a SEARCH state to search for a synchronized communications channel.