초록 ▼

A network hub switching center routes communications from and to a plurality of RTUs. CTSs transmit data to the RTUs dispersed over a predetermined CTS geographic area and the RTUs present multiplexed digital data which is synchronously related to the CTS broadcast signal for communication with iden

A network hub switching center routes communications from and to a plurality of RTUs. CTSs transmit data to the RTUs dispersed over a predetermined CTS geographic area and the RTUs present multiplexed digital data which is synchronously related to the CTS broadcast signal for communication with identified individual RTUs within designated geographic areas. A number of intermediate receivers are provided with each CTS for receiving messages from low-powered local RTUs. The intermediate receivers are located at a set of cell subdivision sites, which are partitioned from the CTS geographic area and are dispersed over the CTS geographic area. The CTS data processing and transmission facilities provides for synchronizing the transmission facilities with a precision clock signal derived from an independent precision clock source. The clock source is independent of the radio broadcast signals when the interactive radio network operates in conjunction with a source of radio broadcast signals. In one embodiment, the precision clock signal is obtained, for example, from a Global Positioning System (GPS) network. The CTSs and RTUs operate in a band of carrier frequencies between 218-219 MHz. The RTUs transmit on a plurality of frequencies, and the receive-only intermediate receivers at different subdivision sites operate on different ones of said frequencies within the 218-219 MHz band.

대표청구항 ▼

An interactive radio broadcast data system comprising: at least one low power mobile remote transmitter unit (RTU) located in at least one of a plurality of geographic zones of at least one geographic area, a receive only station disposed within said at least one of said plurality of geographic zone

An interactive radio broadcast data system comprising: at least one low power mobile remote transmitter unit (RTU) located in at least one of a plurality of geographic zones of at least one geographic area, a receive only station disposed within said at least one of said plurality of geographic zones for reception of transmissions from said at least one RTU located in said at least one of said plurality of geographic zones, a central transmitting station (CTS) disposed within said at least one geographic area, said CTS communicatively coupled to said receive only station disposed within said at least one of said plurality of geographic zones, said CTS having data processing and transmission facilities for transmitting data to said at least one RTU and for receiving from said receive only station multiplexed synchronously related digital data messages of variable lengths, said data processing and transmission facilities including means for synchronizing said transmission facilities with a precision clock signal derived from an independent precision clock source, and facilities in said CTS and said at least one RTU for handing off communications between said plurality of geographic zones when communicated signals deteriorate below a given threshold, said system operating in conjunction with a source of radio broadcast signals.