A location tracking system for determining the location of persons and objects using transmitters that transmit location messages to at least one receiver connected to a computing device in a network of computing devices, comprising: a plurality of battery-powered, radio frequency, RF, transmission-capable only transmitters, TXs,, each of which is carried by the person, or attached to the object, whose location is to be determined; at least one RF receiver, RX,, each of which receives location messages transmitted by transmitters of said TXs within signal range of the RX; at least one computing device, each of which is in communication with a different one of the RX and receives data messages from the RX each of which is generated using a location message received from a TX; and a centralized computing device which is in communication with each of the computing devices associated with a RX via said network, wherein said centralized computing device determines the location of each person carrying a TX or object having an attached TX, using data derived from data messages forwarded to it from a computing device associated with a RX, characterized in that the location messages transmitted by each TX comprise error detection data, wherein the error detection data comprises a message count which is incremented each time a TX transmits a location message and a checksum value and wherein the RX determines whether a location message received from a TX has a message count one increment above the last previously received location message transmitted from that TX, and whenever it is not, foregoes providing a data message corresponding to the out-of-sequence location message to the computing device associated with the RX. a plurality of battery-powered, radio frequency, RF, transmission-capable only transmitters, TXs,, each of which is carried by the person, or attached to the object, whose location is to be determined; at least one RF receiver, RX,, each of which receives location messages transmitted by transmitters of said TXs within signal range of the RX; at least one computing device, each of which is in communication with a different one of the RX and receives data messages from the RX each of which is generated using a location message received from a TX; and a centralized computing device which is in communication with each of the computing devices associated with a RX via said network, wherein said centralized computing device determines the location of each person carrying a TX or object having an attached TX, using data derived from data messages forwarded to it from a computing device associated with a RX, characterized in that the location messages transmitted by each TX comprise error detection data, wherein the error detection data comprises a message count which is incremented each time a TX transmits a location message and a checksum value and wherein the RX determines whether a location message received from a TX has a message count one increment above the last previously received location message transmitted from that TX, and whenever it is not, foregoes providing a data message corresponding to the out-of-sequence location message to the computing device associated with the RX.