Patent ID: 8203981

Claim:
A wireless sensor network comprising a plurality of nodes linearly connected from a sink node to a terminal node by connecting each node to a single upper-level node and a single lower-level node, wherein each node has an active period for transmitting/receiving data to/from its upper-level node and lower-level node, and wherein the active period includes a downstream duration for transmitting data/commands from the sink node to the terminal node and an upstream duration for transmitting data/commands from the terminal node to the sink node, and an intermission duration between the downstream duration and the upstream duration, wherein no data is transmitted/received to/from its upper-level node during the intermission duration, wherein the intermission duration of each node is determined based on a depth of the node and the number of hops included in the entire network, wherein each of the downstream duration and the upstream duration includes a receive (RX) interval, a transmit (TX) interval, and an acknowledgement (ACK) interval, and wherein all the nodes linearly connected from the sink node to the terminal node perform bidirectional communication within a single active period.