A method of determining the physical position of a movable node in a network, comprising: sending a first signal from a first transmitting reference node to a first receiving reference node and the movable node, the first transmitting reference node and the first receiving reference node forming a first pair of reference nodes; receiving the first signal in the movable node and sending a second signal from the movable node to the first receiving reference node in phase with the first signal; receiving the first signal and the second signal in the first receiving reference node and comparing the phase of the received first and second signals; characterized by sending a third signal from a second transmitting reference node, different from the first transmitting reference node, to a second receiving reference node, different from the first receiving node, and the movable node, the second transmitting reference node and the second receiving reference node forming a second pair of reference nodes; receiving the third signal in the movable node and sending a fourth signal from the movable node to the second receiving reference node in phase with the third signal; receiving the third signal and the fourth signal in the second receiving reference node and comparing the phase of the received third signal and the received fourth signal; and determining the position of the movable node based on the phase difference between the received first and second signals and on the phase difference between the received third and fourth signals; wherein the first transmitting reference node, the first receiving reference node, the second transmitting reference node, and the second receiving reference node are positioned such that a line between the first transmitting reference node and the first receiving reference node is orthogonal to a line between the second transmitting reference node and the second receiving reference node. sending a first signal from a first transmitting reference node to a first receiving reference node and the movable node, the first transmitting reference node and the first receiving reference node forming a first pair of reference nodes; receiving the first signal in the movable node and sending a second signal from the movable node to the first receiving reference node in phase with the first signal; receiving the first signal and the second signal in the first receiving reference node and comparing the phase of the received first and second signals; characterized by sending a third signal from a second transmitting reference node, different from the first transmitting reference node, to a second receiving reference node, different from the first receiving node, and the movable node, the second transmitting reference node and the second receiving reference node forming a second pair of reference nodes; receiving the third signal in the movable node and sending a fourth signal from the movable node to the second receiving reference node in phase with the third signal; receiving the third signal and the fourth signal in the second receiving reference node and comparing the phase of the received third signal and the received fourth signal; and determining the position of the movable node based on the phase difference between the received first and second signals and on the phase difference between the received third and fourth signals;