Patent ID: 8121080

Claim:
A beacon scheduling method for preventing beacon overlapping in a ZigBee network including routers each with a beacon slot number according to a specific time slot, the method comprising: (a) identifying beacon slot numbers of routers existing in the ZigBee network by scanning beacons of the routers; (b) selecting a parent router to be connected among the routers; (c) distinguishing unused beacon slot numbers, excluding the identified beacon slot numbers, among beacon slot numbers allocated within a beacon interval; and (d) selecting one of the unused beacon slot numbers and transmitting beacons based on a difference between a beacon slot number of the selected parent router and the selected unused beacon slot number; (e) transmitting a message from a router with an allocated beacon slot number among the routers in the ZigBee network to a sink node in the ZigBee network, the message containing the allocated beacon slot number of the router and a scan time; and (f) if there is a router with the same allocated beacon slot number or the same scan time as in the message, transmitting a reset command to delete the beacon slot number of one of the two routers, wherein (f) comprises: determining whether an allocated beacon slot number of a router which will transmit beacons is the same as the allocated beacon slot number included in the transmitted message; if the allocated beacon slot numbers of the two routers are the same, calculating a scan time interval using a difference between the scan times of the two routers; and if the calculated scan time interval is not greater than the product of multiplying a beacon interval of the routers by a predetermined integer, transmitting a reset command for system initialization to one of the two routers after the time corresponding to the product passes.