A multilaterating two-way message delivery system for mobile resource management provides efficient two-way radio data communication for multitudes of portable transponders using a single frequency in half-duplex communication. The system includes at least one transponder device which transmits and receives data using a radio frequency communication link, and an array of at least three base stations which communicate with the transponder device using the radio frequency communication link. The radio frequency communication link employed by each base station and the transponder device is designed to provide multilateration information and to deliver message data simultaneously. Further, a control arrangement is coupled to the array of base stations to coordinate the communication between the base stations and the transponder devices. Time-division multiplex and spread spectrum technology is employed by the system for communication efficiency and minimizing the effect of multipath interference.