A location system comprising one or more master units and one or more slave units (12, 14, 16); the or each master unit comprising: a long-range wireless transceiver, a short range wireless transceiver and a location detection means operatively connected to the short-range wireless transceiver wherein the short-range wireless transceiver is adapted to broadcast an of the master unit and the location of the master unit as determined by the master unit's location detection means; the or each slave unit (12, 14, 16) comprising: a short-range wireless transceiver and a location detection means operatively connected to the short-range wireless transceiver wherein the short-range wireless transceiver is adapted to broadcast an ID of the slave unit and the location of the slave unit (12, 14, 16) as determined by the slave unit's location detection means; wherein the short-range wireless transceivers of the master and slave units (12, 14, 16) are: adapted to receive the IDs and the locations of other in-range master or slave units (12, 14, 16); and to broadcast a first data signal comprising the ID and the location of said master or slave unit (12, 14, 16) and the IDs and locations of other in-range master or slave units (12, 14, 16); and wherein the short-range wireless transceivers of the master units are: adapted to receive the first data signals of in-range master or slave units (12, 14, 16); and to broadcast a second data signal comprising the IDs and locations of the master and slave units (12, 14, 16) contained in the received first data signals; and wherein the or each master unit is adapted to selectively broadcast the second data signal via the long-range wireless transceiver. the or each master unit comprising: a long-range wireless transceiver, a short range wireless transceiver and a location detection means operatively connected to the short-range wireless transceiver wherein the short-range wireless transceiver is adapted to broadcast an of the master unit and the location of the master unit as determined by the master unit's location detection means; the or each slave unit (12, 14, 16) comprising: a short-range wireless transceiver and a location detection means operatively connected to the short-range wireless transceiver wherein the short-range wireless transceiver is adapted to broadcast an ID of the slave unit and the location of the slave unit (12, 14, 16) as determined by the slave unit's location detection means; wherein the short-range wireless transceivers of the master and slave units (12, 14, 16) are: adapted to receive the IDs and the locations of other in-range master or slave units (12, 14, 16); and to broadcast a first data signal comprising the ID and the location of said master or slave unit (12, 14, 16) and the IDs and locations of other in-range master or slave units (12, 14, 16); and wherein the short-range wireless transceivers of the master units are: adapted to receive the first data signals of in-range master or slave units (12, 14, 16); and to broadcast a second data signal comprising the IDs and locations of the master and slave units (12, 14, 16) contained in the received first data signals; and wherein the or each master unit is adapted to selectively broadcast the second data signal via the long-range wireless transceiver.