Patent ID: 8233420

Claim:
A method by which a source node operates in a wireless multi-hop network, the method comprising: selecting one among first to M-th frame structures, wherein M is a natural number greater than or equal to 2, based on a data packet generation interval; when the source node is in an active state, synchronizing with neighboring nodes in a first synchronization period of the selected frame structure; and when the source node is in the active state, transmitting a control packet to a next hop in a data period of the selected frame structure, and waiting for a response from the next hop, the control packet indicating that the source node will transmit a data packet in a sleep period subsequent to the data period and including information on the selected frame structure, wherein each of the first to M-th frame structures defines a frame including at least one synchronization period, at least one data period, and at least one sleep period, and each of the first to M-th frame structures having a different duty cycle.