Method of wireless ranging

A method of wireless ranging between an initiator node and a responder node, comprising:

• for each nominal frequency in a plurality of different nominal frequencies, performing a measurement procedure resulting in a two-way phase measurement between the initiator node and the responder node, the measurement procedure comprising:
• the initiator node transmitting an initiator carrier signal, the frequency of the initiator carrier signal being derived from an initiator node clock reference;
• the responder node performing a phase measurement of the initiator carrier signal relative to a responder node clock reference;
• the responder node transmitting a responder carrier signal, the frequency of the initiator carrier signal derived from the responder clock reference;
• and
• the initiator node performing a phase measurement of the responder carrier signal relative to the initiator node clock reference,
• the method further comprising:
• calculating a distance between the initiator node and the responder node using as input:
• the two-way phase measurements for the plurality of different nominal frequencies;
• and
• a clock reference offset correction of the initiator node and of the responder node.