An ad hoc network having self-organized clusters of nodes, i.e., one-hop ad hoc subnetworks. Any node can assume the role of a routing node if it is able to communicate with at least one node in another cluster so as to self-organize the clusters of nodes into a multi-hop ad hoc network. An intra-cluster synchronization of sleep and awake periods of nodes in a power-saving mode of operation is performed separately within each cluster. An inter-cluster synchronization of awake periods of neighboring clusters to be temporally non-overlapping is performed by the routing nodes.