Passive synchronization in wireless networks

摘要

A method for synchronizing a node to a data sink determines a first time of receiving by the node a packet transmitted by a neighboring node and a second time of receiving by the data sink or a synchronized neighboring node the packet transmitted by the neighboring node. The node is synchronized to the data sink based on the difference between the first time and the second time.

主权项

1. A method for synchronizing a node to a data sink in a wireless network of nodes organized into Destination Oriented Directed Acyclic Graph (DODAG) topology, comprising:
transmitting enhanced DODAG information object (DIO) messages from the data sink to the node; transmitting enhanced destination advertisement object (DAO) messages from the node to the data sink; determining a first time of receiving by the node a packet transmitted by a neighboring node; determining a second time of receiving by the data sink or a synchronized neighboring node the packet transmitted by the neighboring node; synchronizing the node to the data sink based on the difference between the first time and the second time; receiving, by the node, a SYNC-REQ packet transmitted by the neighboring node in response to receiving a SYNC-START packet transmitted by the data sink or the synchronized neighboring node; receiving, by the node, a SYNC-RES packet transmitted by the data sink or the synchronized neighboring node in response to receiving the SYNC-REQ packet; determining the offset between the clock of the node and a clock of the data sink based on a time of receiving the SYNC-REQ packet by the node and by the data sink or the synchronized neighboring node; and synchronizing the node to the data sink based on an offset between a clock of the node and a clock of the data sink.