A method determines the propagation delays between nodes in a network, the network including a plurality of nodes. The method includes recording by each one of the nodes the transmission time of a beacon-signal respective of the one of the nodes and the reception times of other beacon-signals respective of other nodes. The beacon signal and the other beacon signals are transmitted according to a forward transmission sequence, a reverse transmission sequence is determined according to the forward transmission sequence. The procedure of recording for beacon signals is repeated and transmitted according to the reverse transmission sequence, and a propagation delay is determined between each pair of communicating nodes according to a forward propagation delay and a reverses propagation delay respective of the each of pair of communicating nodes. The forward propagation delay and the reverse propagation delay are determined according to the recorded times of transmissions and receptions of the beacon signals by the respective nodes. The pair of communicating nodes are defined as a pair of nodes that can receive transmissions of each other, and the time difference between transmissions of beacon signals respective of two nodes, during the forward transmission sequence, is substantially the same as the time difference between transmissions of the beacon signals respective of the two nodes, during the reverse transmission sequence.