Patent ID: 7840240

Claim:
A wireless network node, comprising: a transmitter; a receiver; and an interface for connection to the outside, wherein, when a master unit calls a wireless network node, the wireless network node generates a random number in response to the received call signal so as to prevent collision against other wireless network nodes, converts the random number into a time slot value, and transmits its unique number to the master unit at that time slot by return, when receiving the unique number, the master unit transmits, to the wireless network node, the unique number of the wireless network node by return, when receiving the return unique number from the master unit, the wireless network node shuts off the power supply to a transmitting/receiving circuit for a predetermined time, and the master unit transmits the power supply shutoff time of the transmitting/receiving circuit of the wireless network node according to the priority of the wireless network node when transmitting the unique number to the wireless network node by return.