KR0165089B1 - Paging information receiving device using mpeg-ñ null packet for satellite broadcasting - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paging information transmission network using a communication satellite. The present invention relates to a paging information receiving apparatus for receiving paging information transmitted on a null packet of an MPEGII packet used in a satellite broadcasting system.

In the conventional paging system, since paging information is transmitted through a communication satellite by using a dedicated radio channel for transmitting paging information, communication costs are high and there is a problem in that paging service cannot be economically performed.

According to the present invention, when a satellite broadcasting system broadcasting through a communication satellite is configured to transmit voice and video into MPEGII packets and transmits paging information to empty packets generated during transmission, paging information carried on empty channels of the corresponding MPEGII packets may be received. This makes the paging service economical.

Description

Paging information receiver using MPEGII empty packet for satellite broadcasting

1 is a diagram illustrating a wide area paging transmission network using a conventional microsatellite base station.

2 is a conceptual diagram of wide-area paging transmission and reception according to the present invention.

3 is a structural diagram showing an MPEGII packet structure including paging information according to the present invention;

4 is a structural diagram showing the structure of a POCSAG message.

5 is a block diagram of an apparatus for receiving paging information according to the present invention.

6 is a flowchart illustrating a paging information extraction operation of the paging information receiving apparatus according to the present invention.

* Explanation of symbols for main parts of the drawings

10: satellite broadcasting base station 20: communication satellite

30 receiver 40 paging transmitter station

31: Tuner part 32: QPSK demodulation part

33: error correction 34: system demux unit

35 memory unit 36 microprocessor unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paging information transmission network using a communication satellite, and more particularly, to a paging information receiving apparatus for receiving paging information carried on a null packet of an MPEGII packet used in a satellite broadcasting system.

Conventionally, in the case of providing a paging service using a communication satellite, the method is as shown in FIG. When a subscriber who wants to make a call attempts to make a call using a telephone, the paging signal is applied to the exchange 5 via the public switched telephone network (PSTN) only when a wide area call is desired. At this time, the switch 5 transmits the authorized paging signal to the communication satellite 7 side via the central management system 6. The signal transmitted to the communication satellite 7 side is converted to the downlink frequency by the communication satellite 7 and transmitted to the small earth stations 1a to 1f on the ground, and the small earth stations 1a to 1d receive the paging information. Is extracted and output to the paging transmitters 2a to 2d connected to it. Accordingly, the paging sender 2a to 2d temporarily stores the corresponding paging information, transmits the paging information to the area under its control over the wireless channel, and receives the paging information sent by the paging sender 2a to 2d. do.

In the conventional paging system as described above, since paging information is transmitted through a communication satellite using a dedicated radio channel for transmitting paging information, communication cost is high and there is a problem in that paging service cannot be made economically.

The present invention has been made to solve the above-mentioned problems, and when the satellite broadcasting system broadcasting through a communication satellite to transmit the paging information to the empty packet generated when transmitting the audio and video in MPEGII packets An object of the present invention is to provide a paging information receiving apparatus capable of economically providing a paging service by receiving paging information carried on a common channel of a corresponding MPEGII packet.

The present invention for achieving the above object, the tuner unit for receiving the RF signal received and supplied by the LNB to select and output the RF signal of the desired frequency; A QPSK demodulator for outputting digital data extracted by QPSK demodulation of the RF signal applied from the tuner; An error correction unit for correcting an error of digital data applied from the QPSK demodulator and outputting error corrected digital data; A system demux unit for receiving digital data from the error correction unit and separating and outputting paging information from the digital data; A memory unit for storing paging information applied from the system demux and outputting the paging information to a paging transmitting station; And a microprocessor unit for controlling operations of the tuner unit, the QPSK demodulation unit, the error correction unit, the system demux unit, and the memory unit.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The wide-area paging transmission / reception system according to the present invention comprises a satellite broadcasting transmitting earth station 10, a communication satellite 20, a receiver 30, and a paging transmitting station 40 as shown in FIG. The satellite carrier transmitting base station 10 transmits broadcast information and paging information to the communication satellite 20 via a wireless channel. In case of transmitting broadcast information, audio and video information is coded by MPEGII method, composed of MPEGII packets, and transmitted to the communication satellite 20 through an antenna, and in case of transmitting paging information, an empty packet generated when transmitting MPEGII packets. Paging information is loaded to the communication satellite 20 through the antenna. The communication satellite 20 transmits the broadcasting information and paging information received from the satellite broadcasting base station 10 to the ground. The broadcast information transmitted from the communication satellite 20 is received by the satellite broadcast subscriber to provide the broadcast contents to the subscriber, and the paging information transmitted from the communication satellite 20 is received by the receiver 30 for paging. Is applied to the transmitting station 40. The paging transmitting station 40 transmits paging information applied from the receiver 30 to the paging subscriber in the corresponding region through the antenna.

As shown in FIG. 5, the receiver 30 receiving the paging information transmitted on the empty packet of the MPEGII packet from the communication satellite 20 includes a tuner unit 31, a QPSK demodulation unit 32, and error correction unit. (33), the system demux 34, the memory 35 and the microprocessor 36 is formed. The tuner unit 31 receives an RF signal received and applied by a low noise blockdown converter (LNB), selects an RF signal having a desired frequency under the control of the microprocessor unit 36, and outputs the RF signal to the QPSK demodulator 32. do. The QPSK demodulator 32 outputs the digital data extracted by QPSK (Qudrature Phase Shift Keying) demodulation under the control of the microprocessor unit 36 to the RF signal applied from the tuner unit 31 to the error correction unit 33. do. The error correction unit 33 corrects an error of the digital data string applied from the QPSK demodulation unit 32 under the control of the microprocessor unit 36, and corrects the error corrected digital data string to the system demux unit 34 side. Output The system demux 34 receives the digital data stream from the error correction unit 34 and separates the paging information from the digital data stream under the control of the microprocessor unit 36 and outputs the paging information to the memory unit 35. . The memory unit 35 stores paging information applied from the system demux unit 34 and outputs the paging information to the paging transmitting station 40 under the control of the microprocessor unit 36.

The paging system as described above operates as follows when transmitting paging information. Satellite Broadcasting When the earth station 10 transmits the video and audio information for broadcasting to MPEG2 packet and transmits it to the communication satellite 20 side, it outputs a certain amount of data. The packet is inserted and sent to the communication satellite 20 side. When the satellite broadcasting transmitting earth station 10 transmits paging information to such empty packet and transmits it, the batch of Post Office Code Stadardization Advisory Group (POCSAG) message as shown in FIG. 4 is loaded on the MPEGII empty packet. In this case, the 184 byte area of the MPEGII empty packet as shown in FIG. 3 is designated as the message area, and the first to fourth batches of POCSAG codes are carried in the message area. As described above, when the satellite broadcasting earth station 10 loads paging information on an empty packet of an MPEG II packet and transmits the paging information to the communication satellite 20, the communication satellite 20 converts the RF signal into a downlink signal and transmits it to the ground. At this time, the receiver 30 receives the corresponding RF signal, extracts the paging information, and outputs the paging information to the paging transmitter station 40.

That is, when the LNB receives the RF signal applied from the communication satellite 20 and inputs it to the tuner unit 31, the tuner unit 31 receives the RF signal of the desired frequency under the control of the microprocessor unit 36. Selects and outputs the QPSK demodulator 32 to the QPSK demodulator 32, and the QPSK demodulator 32 outputs the digital data string extracted by QPSK demodulation under the control of the microprocessor unit 36. To the side. At this time, the error correction unit 33 corrects an error of the digital data sequence applied from the QPSK demodulation unit 32 under the control of the microprocessor unit 36 to output the system demux unit 34 to the system demux unit 34. The unit 34 receives the digital data stream from the error correction unit 33, separates the paging data from the digital data stream under the control of the microprocessor unit 36, and outputs the paging data to the memory unit 35. Reference numeral 35 stores paging data applied from the system demux unit 34 under control of the microprocessor 36 and outputs the paging data to the paging transmitting station 40 side. Accordingly, the paging transmitting station 40 calls the paging subscriber by sending the paging data applied from the memory unit 35 of the receiver 30 to the corresponding area.

Mugunghwa satellite has assigned three transponders for satellite broadcasting, and up to eight channels can be provided to one transponder in digital broadcasting, but it is currently designed to serve four channels. The receiver 30 is configured to extract paging data supported by four broadcast channels applied from the communication satellite 20. That is, the receiver 30 receives paging information carried on an empty packet of MPEGII packets corresponding to four broadcast channels. As shown in FIG. 6, the receiver 30 sets the register of the memory unit 35 to an initial state. After that, only the paging information contained in the empty packet is extracted from the data stream and sequentially stored in the memory unit 35 in the MPEGII packets sequentially applied, and the paging information from the first channel to the fourth channel is extracted in order. The data is stored in the unit 35 and transmitted to the paging transmitting station 40 side. At this time, the paging transmitting station 40 calls the paging subscriber by transmitting the corresponding paging information from the receiver 30 to the paging subscriber of the region through the wireless channel.

As described above, according to the present invention, when a satellite broadcasting system broadcasting through a communication satellite transmits paging information to an empty packet generated when transmitting audio and video into MPEGII packets, the present invention is carried on an empty channel of the corresponding MPEGII packet. Since paging information can be received, paging service can be made economical.

Claims (1)

A tuner unit which receives an RF signal received and supplied by the LNB and selects and outputs an RF signal having a desired frequency; A QPSK demodulator for outputting digital data extracted by QPSK demodulation of the RF signal applied from the tuner; An error correction unit for correcting an error of digital data applied from the QPSK demodulator and outputting error corrected digital data; A system demux unit for receiving digital data from the error correction unit and separating and outputting paging information from the digital data; A memory unit for storing paging information applied from the system demux unit and outputting the paging information to a paging transmitting station; And a microprocessor unit for controlling operations of the tuner unit, the QPSK demodulation unit, the error correcting unit, the system demux unit, and the memory unit.