Provided are a system and method for position awareness that can be used
indoors in a large-scale environment and can minimize generation of radio
frequency (RF) and ultrasonic waves in a wireless sensor network
including low-priced sensor nodes capable of precise position
measurement, thus improving energy efficiency by reducing unnecessary
power consumption. The method includes the steps of: (a) calculating
initial position coordinates using beacon information received from
adjacent beacons through a broadcast beacon solicitation signal, sending
a synchronization signal to the beacons, and synchronizing the beacons;
(b) receiving ultrasonic waves generated from the adjacent beacons
activated by a broadcast start message, and calculating position
coordinates; and (c) when the calculated position coordinates correspond
to a predetermined hand-off threshold position, transmitting a hand-off
process message to a newly activated beacon, and executing a hand-off
process routine.