Method of synchronization and link access for low energy critical infrastructure monitoring network

摘要

The present invention provides a time synchronization method in a low energy critical infrastructure monitoring network and a coordinate access method using a superframe. According to the exemplary embodiments of the present invention, time synchronization can be promptly and efficiently performed in the low energy critical infrastructure monitoring network, a link access method with three grades of link access can be provided, and a frame structure and a process for link generation, link management, and extended connection are provided.

主权项

1. A time synchronization method of a device included in personal area networks (PAN), comprising:
receiving a plurality of beacons from a coordinator included in the network; estimating a reception time of an nth beacon after the received plurality of beacons; checking a real reception time of the nth beacon; calculating a clock drift that is a difference between the estimated reception time and the real reception time; and applying the clock drift to the time synchronization based on statistical processing of the clock drift; wherein the estimating the reception time comprises: estimating a beacon interval based on the received beacons; calculating a sleep time based on the estimated beacon interval; sleeping for the sleep time, and waiting reception of a first beacon from the coordinator during a beacon reception waiting time; when receiving the first beacon, estimating the reception time of the nth beacon to obtain the estimated reception time, based on the estimated beacon interval and serial number information included in the first beacon; when reception of a third beacon has failed, changing the beacon reception waiting time and waiting for reception of the third beacon from the coordinator during the changed beacon reception waiting time; and when the reception of the third beacon has failed during the changed beacon reception waiting time, extending the sleep time, sleeping for the extended sleep time, and then waiting for reception of the third beacon from the coordinator during the beacon reception waiting time.