| 摘要 |
<p>The invention refers to a method for data transmission over the MAC layer in a mesh network comprising several nodes, each node being operated based on a duty cycle comprising an active time interval in which the node is in an active state and an inactive time interval in which the node is in an inactive state. Frames are transmitted between a first node and a second node such that, in case that the first node detects that a frame is not received by the second node, the active time interval of the first node is incremented and the frame is retransmitted. This incrementing step combined with a retransmission of the frame is preferably repeated several times. Due to the incrementing step, the probability of an overlap between the active time intervals of neighboring nodes in enhanced such that the connectivity of the network nodes in the MAC layer is improved. After having performed one or more incrementing steps, the active time interval is decremented in one or more decrementing steps in order to reduce the power consumption of the nodes. Due to the incrementing and decrementing steps, a mesh network is established providing high connectivity as well as low power consumption of the nodes. Another advantage of the invention is that the nodes do not have to synchronize their active time intervals with each other, e.g. by transmitting beacons, resulting in a fully decentralized scheme for reducing power. Preferably, the invention is used in the non beacon enabled mode in the wireless MAC layer of the standard IEEE 802.15.4.</p> |
