초록 ▼

A satellite communication system by which information of afflicted areas can be collected rapidly and accurately at the time of disaster such as an earthquake or the like, and which is easy to introduce. In the system, a center station accommodates a plurality of extensions of a private branch excha

A satellite communication system by which information of afflicted areas can be collected rapidly and accurately at the time of disaster such as an earthquake or the like, and which is easy to introduce. In the system, a center station accommodates a plurality of extensions of a private branch exchange. Portable terrestrial stations are made to one-to-one correspond to the extensions accommodated in the private branch exchange and the center station connects the extensions to the corresponding portable terrestrial stations. The respective frequency bands of a communication satellite to be used for the transmission from each of the portable terrestrial stations to the center station and for the transmission from the center station of each of the portable terrestrial stations corresponding to the one extension are stationarily secured. Each portable terrestrial station is small-sized so as to be portable by a person or by a motorcycle.

대표청구항 ▼

[ What is claimed is:] [1.] A satellite communication system comprising a center station and a plurality of portable terrestrial stations so that said center station and said plurality of portable terrestrial stations can perform communication with each other through a communication satellite,said c

[ What is claimed is:] [1.] A satellite communication system comprising a center station and a plurality of portable terrestrial stations so that said center station and said plurality of portable terrestrial stations can perform communication with each other through a communication satellite,said center station including:antenna for receiving a portable terrestrial station transmission signal being transmitted from any of said portable terrestrial stations through said communication satellite and being constituted by a transmission frame containing message data and a portable terrestrial station ID, and for transmitting a center station transmission signal for said respective portable terrestrial stations to said communication satellite;a transmitter-receiver including a reception portion for demodulating/decoding a transmission signal constituted by a transmission frame from each of said portable terrestrial stations and received by said antenna, and a transmission portion for encoding/modulating a signal transmitted from said center station and constituted by a reference frame and frames for said plurality of portable terrestrial stations, and for transmitting the modulated signal as a transmission signal of said center station to said communication satellite through said antenna;a selection portion including a reception system portion and a transmission system portion, said reception system portion being adapted to selectively send control data of the message data and the portable terrestrial station ID of the transmission frame to a controller portion, to selectively send data including aural data other than the control data of said message data to a subscriber's line connection control portion, and to select a line of an extension corresponding to the portable terrestrial station ID of said transmission frame in response to the portable terrestrial station ID of said transmission frame and correspondence between portable terrestrial station IDs and extensions established by said controller portion, said transmission system portion being designed so that said transmission system portion recognizes a predetermined one of said portable terrestrial stations, that is, a destination portable terrestrial station, in response to the extension set by said controller portion and the portable terrestrial station when transmission message data for portable terrestrial stations from said subscriber's line connection control portion is to be sent to said destination portable terrestrial station; forms a portable terrestrial station frame for the destination portable terrestrial station containing a portable terrestrial station ID of the recognized destination portable terrestrial station and said message data; and sends the thus formed frame and the reference frame formed by said controller portion in time-division-multiplex to said transmitter-receiver; andsaid subscriber's line connection control portion including a reception system having an accommodation portion accommodating extensions of a private branch exchange and a controller portion for controlling said extensions assigned to said respective portable terrestrial stations in accordance with the contents of the reception message data, and a transmission system for detecting the state of every extension, for forming information data to control a call in accordance with the detected state and for sending message data obtained by adding a message ID to said information data to said selection portion through a line corresponding to said extension;each of said portable terrestrial stations including:a transmitter-receiver having a reception antenna for receiving a transmission signal from said center station; a reception system portion for demodulating and decoding the signal received by said reception antenna and for separating the reference frame and the frame for the portable terrestrial station from each other; a transmission system portion for modulating the transmission frame from a second selection portion, for encoding the modulated signal to obtain a spectrum diffusion coded signal, and for supplying the coded signal to a transmission antenna; and a transmission antenna for transmitting said coded signal;a first selection portion for transmitting the contents of said reference frame, and the permission flag and information data for controlling a call of the message data for the portable terrestrial station, a line connection control portion;a second selection portion for generating the transmission frame containing the message data and its own portable terrestrial station ID and for supplying the generated transmission frame to the transmission system portion of said transmitter-receiver;a controller portion for transmitting message data of the transmission frame in which a message ID is added to control data of the message data to said second selection portion, when said transmission frame is to be sent to said center station; andsaid line connection control portion including: a reception system portion having a controller portion for controlling a telephone portion in accordance with the contents of the message data from said first selection portion; and a transmission system portion for generating information data for controlling a call from said telephone portion and for transmitting the information data to said second selection portion.