Method and a system for hierarchical time synchronization in an ad-hoc network

A system for time synchronization within a mobile ad-hoc network comprising several nodes each transmitting a message signalling a presence, in each case within a given time frame,

• whereas an acknowledgement of the message signalling a presence is implemented by means of an acknowledgement message by every node disposed within the transmission range of the node transmitting a message signalling a presence,
• whereas, in each case from two nodes disposed within the transmission range of one another, a node is specified with the local time of which the local time of the respectively other node is synchronized,
• whereas the specification of the node is implemented on the basis of information in the acknowledgement message received from one of the two nodes disposed within the transmission range of one another, and
• whereas of the two nodes disposed within the transmission range of one another, that node is specified, of which the local time provides maximum time accuracy or which is integrated in another ad-hoc network with a node of which the local time provides the maximum time accuracy.

A method for time synchronization in a mobile ad-hoc network, comprising:

• transmitting by every node of the mobile ad-hoc network of a message signalling a presence, in each case within a given time frame,
• acknowledging by every node disposed within the transmission range of the transmitting node of the received message signalling a presence, in each case with an acknowledgement message,
• specifying of that node of two nodes disposed within the transmission range of one another with the local time of which the respectively other node synchronizes its local time, on the basis of information in an acknowledgement message which is received by one of the two nodes, and
• synchronizing of the local time of the nodes with the local time of the respective specified node,
• wherein in the case of an ad-hoc network formed from only two nodes of which the local times provide an identical time accuracy, that node is specified which first transmits an acknowledgement message to a message signalling a presence of the two nodes.