Patent ID: 8411648

Claim:
A wireless sensor network having a plurality of nodes each communicating over a wireless communication link, wherein at least one of the plurality of nodes is connected to a sensor, wherein each of the nodes has an active duration so as to transmit and receive data with respect to an upper node and a lower node, wherein the active duration is configured to include an upstream duration for transmitting data and commands from a terminal node to a sink node and a downstream duration for transmitting data and commands from a sink node to a terminal node, wherein each of the downstream duration and the upstream duration is configured to sequentially include a second receive slot RX 2 , a second receive processing slot RXP 2 , a first receive slot RX 1 , a first receive processing slot RXP 1 , a transmit slot TX, a transmit processing slot TXP, a first acknowledge slot ACK 1 , a first acknowledge processing slot ACKP 1 , a second acknowledge slot ACK 2 , and a second acknowledge processing slot ACKP 2 , and wherein bidirectional communication can be performed between the sink node and the terminal node in a single period of the active duration.