KR19990061193A - Transmission Data Security Maintenance Method of Multimedia Satellite Communication System - Google Patents

Abstract

The present invention relates to a multimedia satellite communication system for transmitting multimedia data such as image data to a satellite communication subscriber at high speed. The present invention relates to a data communication system comprising a CDMA code and a channel frequency signal which are physically combined with the Internet and transmitted to a set-top box. In the multimedia satellite communication system comprising a set-top box which performs a traffic processing between the control unit and the communication terminal connected to the overall device based on the data allocated from the central station and configured to transmit the packet; A data storage step of storing the received CDMA code and channel frequency data, an initial connection PID generation step of generating a PID for initial connection by combining a unique PID of the set-top box and a common PID received from the central station according to a contracted rule; Initial contact for setting the initial connection PID to the demultiplexer A control message sending step of generating a predetermined message including a unique PID of the set-top box based on the data stored in the data storing step, and sending it to the central station, and from the control message received from the central station after the control message sending step. Resetting the control PID and the traffic PID to the demultiplexer in the initial connection PID detection step of detecting the initial connection PID information generated in the initial connection PID generation step, and the control message detected in the initial connection PID detection step; In addition, it characterized in that it comprises a service information setting step of storing the CDMA code and the channel frequency information in the data memory.

Description

Transmission Data Security Maintenance Method of Multimedia Satellite Communication System

The present invention relates to a multimedia satellite communication system for transmitting multimedia data such as image data to a satellite communication subscriber at high speed, and in particular, it is possible to maintain security of data transmitted in an initialization process of accessing the Internet through a multimedia satellite communication network. The present invention relates to a method for maintaining transmission data security of a multimedia satellite communication system.

In general, a satellite communication system has an advantage of enabling ultra-long distance communication such as communication between countries without having a separate communication line. Therefore, a satellite broadcasting system has already been developed and spread to take advantage of such satellite communication system to directly receive satellite broadcasting in a general home through a set top box, etc. There is also a rapid research on a system for executing satellite communication through a device.

On the other hand, with the recent establishment of a communication method based on TCP / IP (Transport Control Protocol / Internet Protocol), the global Internet network has been established. Unlike the existing PSTN network, such an internet network is based on data packet transmission, so that a large number of subscribers use a single communication line in common, thereby greatly reducing communication costs and enabling multimedia services. . In addition to the construction of the Internet network, data communication using a personal computer has been activated.

1 is a block diagram showing an overall system configuration of a multimedia satellite communication system that enables a subscriber to receive multimedia data at high speed from the Internet or a multimedia service provider as described above.

In FIG. 1, reference numeral 1 denotes a central station connected to the Internet, which performs various network services to terminal stations, and performs overall network operation management and control functions. In addition, reference numeral 3 is a terminal station antenna, 4 is a set top box as a terminal station providing multimedia services to a general subscriber, 5 is a personal computer as a terminal for a user to perform multimedia communication, and 6 is a satellite. to be.

In other words, in the multimedia satellite communication system having the above-described configuration, since the data received from the Internet is much larger than the amount of data transmitted through the Internet, the set-top box 4 from the central station 1 is considered. In case of a forward link transmitted through a TDM scheme, a large amount of messages can be transmitted, and in the case of a return link transmitted from a set-top box 4 to a central station 1, a plurality of subscribers are transmitted. The code division multiple access (CDMA) scheme is used to accommodate this.

In addition, the central station 1 is coupled to the Internet based on TCP / IP, and transmits and receives various data with the Internet through an IP packet (Internet Protocol Packet). Then, for example, an MPEG-2 TS (Transport Stream) packet for a multimedia service is generated based on an IP packet for a subscriber received from the Internet, and the generated packet data is transmitted to the set-top box 4 through the TDM method. do. Then, the CDMA modulated data received from the set-top box 4 is generated, and an IP packet is generated based on this, and then the corresponding IP packet is transmitted to the Internet.

On the other hand, the multimedia satellite communication system having the above configuration has been filed by the present applicant, the detailed configuration and description thereof will be omitted.

Figure 2 illustrates the configuration of a transponder of the system, which is the whole frequency band (f _T and having a frequency band (f _B) of 40MHz for the frequency band (f _A) and a return link to 40MHz for example, for the forward link ), For example, has a bandwidth of 80 MHz, and the return link is composed of a plurality of frequency channels f _{1 to} f _n having a bandwidth of approximately _1.5 MHz. For example, 64 CDMA codes are allocated to each of the frequency channels f _{1 to} fn. The central station 1 provides a channel for each set top box 4 corresponding to the subscriber whenever the subscriber uses the Internet service. By assigning a frequency and a CDMA code, a return link is formed.

That is, the operation of the multimedia satellite communication system having the above-described configuration will be described. First, the central station 1 includes various types of information required when the set-top box 4 requests access to the central station 1, for example, the central station 1. CDMA code and channel frequency data for transmitting a control message, and an information service for providing a PID for the information service for common reception in all set-top boxes (4).

In addition, the information service described above is repeatedly executed at regular intervals, for example, when the number of TS packets transmitted from the central station 1 to the set top box 4 reaches 100.

On the other hand, in the set-top box (4) stores the service information transmitted from the central station (1), that is, CDMA code data, channel frequency data, and PID for information service, which are used when requesting a low speed to the central station (1). do.

When the access request for the Internet, that is, the call connection request, is input from the personal computer 5 in the above state, the set-top box 4 receives the subscriber information input from the computer 5, i.e., the subscriber ID, the password, After generating a predetermined control message based on the subscriber address or the like, the access request is executed to the central station 1 by allocating CDMA code data and channel frequency data.

Subsequently, when the access request is input through the above-described process, the central station 1 first compares the subscriber's IP and password included in the control message with the subscriber's information to determine whether the current access request is a legitimate subscriber. do.

At this time, if it is determined that the subscriber is a legitimate subscriber, the database is searched to determine whether there is a PID currently available, and the control top, traffic PID, channel frequency, and CDMA code are assigned to the set-top box 4. In this case, as the PID of the TS packet transmitted to the set top box 4, an information service PID is used.

In the set top box 4, the control PID and the traffic PID assigned by the central station 1 are set, and the CDMA code and channel frequency data transmitted from the central station 1 are allocated. Then, the personal computer 5 is informed that the call connection is successful.

Subsequently, when the IP packet for transmitting to the Internet from the personal computer 5 is input, the corresponding traffic data is transmitted to the central station 1, and when the central station 1 receives the traffic data from the set-top box 4, It is converted into an IP packet and sent to the Internet.

On the other hand, when a call release request, i.e., an access release request is input from the personal computer 5, the set-top box 4 generates a control message for the call release request and sends it to the central station 1. Then, the central station 1 ends the call processing for the subscriber by retrieving the control PID and the traffic PID allocated to the set top box 4 based on the input control message.

However, in the multimedia satellite communication system, by providing a common information service PID from the central station 1 to all the set top boxes 4, all the set top boxes 4 use the common PID provided by the central station 1. Initial access is made to the central station 1.

Therefore, as described above, all set-top boxes 4 are commonly assigned the same common PID and thus receive initial information through the initial connection, so that the information provided to the terminal connected to any set-top box 4 is different. There is a risk of being stolen.

Accordingly, the present invention has been made in view of the above-described circumstances, and the transmission data security of the multimedia satellite communication system is maintained so that the communication terminal can maintain the security of data transmitted in the initialization process of accessing the Internet through the multimedia satellite communication network. It is an object of the present invention to provide a method and an apparatus thereof.

1 is a block diagram showing the overall configuration of a multimedia satellite communication system.

2 is a block diagram showing the configuration of a transponder of the multimedia satellite communication system of FIG.

3 is a diagram illustrating a configuration of a set-top box 30 to which a transmission data security maintenance apparatus according to an embodiment of the present invention is applied in a multimedia satellite communication system.

4 is a diagram showing the configuration of a central station 1 in a multimedia satellite communication system.

5 is a flowchart illustrating a transmission data security maintaining method of a multimedia satellite communication system according to an embodiment of the present invention.

*** Explanation of symbols for the main parts of the drawing ***

1: central station, 2, 3: antenna,

4, 30: set-top box, 5: personal computer (PC),

6: satellite, 31: RF device,

32: tuner, 33: demodulator,

34: demultiplexer (DMUX), 35: network interface card (NIC),

36: transmission frame generation unit, 37: CDMA channel transmitter,

38: modulator, 39: IF generator,

40: transmission timing generator, 41: data memory,

42: unique PID storage unit, 43: processor,

50: IP switch, 57: transmission data processing device,

62: receiving data processing device, 63: central international language processor,

64: network management system (NMS), 65: database (DB).

The transmission data security maintenance method of the multimedia satellite communication system according to the present invention for realizing the above object is composed of a TS packet and composed of data including a CDMA code and a channel frequency signal which are physically coupled to the Internet and transmitted to the set-top box. And a set-top box which executes traffic processing between the control unit and the communication terminal connected to the whole apparatus based on the data allocated from the central station, comprising: a CDMA code received from the central station; A demultiplexer for initial access PID generation step for generating initial access PID by combining channel frequency data with a data storage step, a unique PID of the set-top box and a common PID received from the central station in a predetermined rule; PID setting step for initial connection, data storage step The control message sending step of generating a predetermined message including a unique PID of the set-top box based on the stored data and sending it to the central station, and the PID generated in the initial connection generation step from the control message received from the central station after the control message sending step. The initial access PID detection step for detecting the initial access PID information, and the control PID and traffic PID are reset in the demultiplexer in the control message detected in the initial access PID detection step, and the CDMA code and channel frequency information are reset. Characterized in that it comprises a service information setting step of storing in the data memory.

That is, according to the present invention having the above-described configuration, when receiving the information service data from the central station, the connection PID generated by the contract rule between the central station and the set-top box is used, and then the information service data allocated from the central station is used. By transmitting the data on the basis of the above, it is possible to realize the transmission data security maintaining method of the multimedia satellite communication system that can secure the transmission data.

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

Figure 3 shows the configuration of a set-top box to which the transmission data security maintenance apparatus is applied in the multimedia satellite communication system according to an embodiment of the present invention.

In FIG. 3, reference numeral 30 denotes a set-top box according to the present invention, and 31 denotes a frequency down-conversion, low-noise amplification by receiving a high frequency signal transmitted from the central station 1, and an intermediate frequency generator 39 to be described later. Is an RF device for frequency-upconverting and amplifying a high frequency output of the intermediate frequency signal outputted from the power amplifier), 32 is a tuner for frequency-converting the high frequency signal outputted from the RF device 31, and 33 is the tuner 32. The demodulator outputs TS packet data by demodulating the intermediate frequency signal output from the QPSK modulated signal.

In the drawing, reference numeral 34 denotes a demultiplexer for extracting a TS packet corresponding to the set-top box from the TS packet data output from the demodulator 33, which includes a register for storing PID information therein. The PID applied from the processor 43 to be described later is stored in the register. The TS packet including the PID stored in the register is extracted from the TS packets applied from the demodulator 33 and applied to the processor 43.

In the figure, reference numeral 35 denotes a network interface card that executes the interface of the personal computer 5, which converts the Ethernet packet applied from the processor 43 into an IP packet to the personal computer 5; In addition to the output box, the IP packet applied by the personal computer 5 is converted into an Ethernet packet and applied to the processor 43.

In the figure, reference numeral 36 denotes a serial transmission data frame based on transmission data applied in parallel from the processor 43, and a transmission timing signal applied by the transmission timing generation unit 40 to be described later. And a transmission frame generator for sequentially outputting the transmission data frames. 37 denotes CDMA modulation by mixing CDMA codes applied from the processor 43 with respect to transmission data output from the transmission frame generator 36. A CDMA channel transmitter to be executed, 38 is a modulator that modulates and outputs the data output from the CDMA channel transmitter 37, for example, QPSK, and 39 is a modulator 38 based on frequency data applied from the processor 43. An intermediate frequency generator converts an output modulation signal into a predetermined intermediate frequency signal.

In the drawing, reference numeral 40 denotes a transmission timing generation unit for generating a transmission timing signal for the transmission frame generation unit 36 under the control of the processor 43, and 41 is assigned from various data, in particular from the central station 1. It is a data memory that stores the control PID, traffic PID and information service PID for receiving service information.

In addition, reference numeral 42 is a unique PID storage unit for storing a unique PID for initial access, which is distinguished from other set-top boxes. For example, a PID consisting of 6 bits is stored, and reference numeral 43 denotes an overall operation of the set-top box 30. As a controlling processor, it stores in the demultiplexer 34 a connection PID generated by combining the unique PID data stored in the unique PID storage unit 42 and the common PID data received from the central station 1 with a contracted rule. If there is an Internet connection request from the computer 5, a control message including a unique PID is generated and sent to the central station 1, and then the control PID and traffic PID allocated from the central station 1 are demultiplexer 34. By registering with, the control data and traffic data transmitted from the central station 1 are received and controlled.

In addition, the processor 43 converts the TS packet for the personal computer 5 received from the demultiplexer 34 into an IP packet and outputs the IP packet to the network interface card 35, and inputs from the network interface card 35. The data from the personal computer 5 to be outputted to the transmission frame generation unit 36 is transmitted to the central station 1.

In addition, the processor 43 allocates a CDMA code from the central station 1 and outputs frequency data to the intermediate frequency generating unit 39, thereby providing CDMA modulation and frequency modulation for data to be transmitted to the central station 1. Will execute control.

4 shows the configuration of the central station 1.

In FIG. 4, reference numeral 50 denotes an IP switch for switching an IP packet, and the IP switch 50 includes a DNS (Domain Name System) server 51, an E-mail server 52, and a web. The (WEB) server 53, the proxy server 54, the multimedia service provider 55, the router 56, and the like are combined.

Here, the router 56 executes connection processing between the central station 1 and the Internet, which converts IP packets input from the Internet into the central station 1 into data of an Ethernet frame, and converts the Internet packets from the central station 1 to the Internet. Ethernet frame sent to IP packet is converted into IP packet.

In the drawing, reference numeral 57 denotes a transmission data processing apparatus for processing the transmission data input from the IP switch 50 to generate, for example, an MPEG-2 TS packet, and 58 denotes an output from the transmission data processing apparatus 57. A modulator for modulating TS packet data, for example, by QPSK and outputting an intermediate frequency signal of, for example, 70 MHz, 59 for frequency upconverting and amplifying the intermediate frequency signal output from the modulator 58, and outputting it to the antenna 2, An RF device converts a high frequency signal received through an antenna 2 into frequency down-conversion and low noise amplification.

In the drawing, reference numeral 60 denotes a demodulation device for demodulating an intermediate frequency signal input from the RF device 59, and 61 denotes a CDMA demodulation data of the CDMA modulated data input by frequency demodulation in the demodulator 60. A CDMA receiving device for outputting packet data, 62 is a receiving data processing device for processing data input from the CDMA receiving device 61, wherein the receiving data processing device 62 is an IP packet data from the set-top box 30 When the control message is received, it is converted into data of the Ethernet frame and input to the IP switch 50. In addition, the reception data processing device 62 converts 100 baseT, that is, 100 MHz data, that is, 100 MHz data input from the CDMA reception device 61 into 10 baseT data, and inputs the data to the IP switch 50.

In the drawing, reference numeral 63 denotes a central international language processor that controls the entire apparatus of the central station 1, and also assigns PIDs to the set-top box 30, transmit channel frequencies and CDMA codes for transmission. 64 is a network management system for the system operator to operate and manage the entire satellite network, 65 is a PID, frequency data and CDMA code data that can be allocated to the set-top box 30, and is stored in the subscriber. Database that stores billing information.

Next, the operation of the apparatus according to the present invention having the above-described configuration will be described with reference to the flowchart shown in FIG.

First, the network management system 64 for the central station 1 has a variety of information required when the set-top box 30 requests access to the central station 1, for example, a CDMA code for transmitting a control message to the central station 1. It provides an information service that provides channel frequency data.

That is, the network management system 64 of the central station 1 generates an Ethernet frame including the CDMA code and the channel frequency data, and transmits the Ethernet frame to the transmission data processing apparatus 57 through the IP switch 50.

Subsequently, the transmission data processing device 57 converts the Ethernet frame transmitted from the IP switch 50 into an IP packet and converts the Ethernet frame into a TS packet, and transmits the TS packet to the modulator 58 and the RF device 59. It is transmitted to the set-top box 30 through.

On the other hand, the set-top box 30 according to the present invention frequency downconverts the CDMA code data and channel frequency data transmitted from the central station 1 through the RF device 31, the tuner 32, and the demodulator 33. Low noise amplification and QPSK modulation are received through the demultiplexer 34 (ST1), and the processor 43 accesses data through the information service, that is, CDMA code data used when requesting a call connection to the central station 1. When the channel frequency data is received, it is stored in the data memory 41 (ST2).

In addition, the processor 43 generates a 13-bit connection PID using the 6Bit unique PID stored in the unique PID storage unit 42 and the received public PID, and sets a 13-bit connection PID. ) Is set (ST3).

Thereafter, when the access request for the Internet, that is, the call connection request, is input from the personal computer 5 in the above state (ST4), the processor 43 generates a unique PID stored in the unique PID storage unit 42 and a network interface. Based on the subscriber information input through the card 35, i.e., the subscriber ID, password, subscriber address data and the public PID, a predetermined control message is generated and sent to the transmission frame generation unit 36, An access request is allocated by allocating access information stored in the data memory 41, that is, CDMA code data and channel frequency data transmitted from the central station 1, to the CDMA channel transmitter 37 and the intermediate frequency generator 39. It is executed (ST5).

On the other hand, in the central station 1, the control message sent from the set top box 30 is input to the demodulation device 60 through the RF device 59, and the access control message is demodulated to which the access is assigned. It is input to the receiving data processing device 62 through the device 60 and the CDMA receiving device 61. In addition, the reception data processing apparatus 62 generates an Ethernet frame based on the control message and applies it to the central international language processor 63 through the IP switch 50.

Subsequently, when the access request is input through the above-described process, the central international language processor 63 first compares the subscriber IP and password included in the control message with the subscriber information stored in the database 65 to access the current access request. It is determined whether the subscriber is a legitimate subscriber.

In this case, if it is determined that the user is a legitimate subscriber, the database 65 is searched to determine whether there is a currently available PID, and the control PID, traffic PID, channel frequency, and CDMA code are assigned to the set-top box 30. . That is, the central international language processor 63 generates an Ethernet frame for transmitting the PID information, the channel frequency data, and the CDMA code, and transmits the Ethernet frame to the transmission data processing apparatus 57 through the IP switch 50. The processing device 57 generates a TS packet based on the Ethernet frame and transmits the TS packet through the modulation device 58 and the RF device 59, wherein the connection PID of the TS packet is transmitted from the set top box 30. A connection PID generated by combining a unique PID and a public PID in a contracted rule, which is the same data as the connection PID set in the demultiplexer 34 of the set-top box 30.

On the other hand, in the set-top box 30, the processor 43 receives a control message made of TS packets sent from the central station 1 through the RF device 31, the tuner 32, and the demodulator 33. (ST6), the received control message, that is, the control PID and the traffic PID are set in the demultiplexer 34, and the CDMA code and channel frequency data allocated from the central station 1 are stored in the data memory 41. (ST7).

Subsequently, when an IP packet for transmitting to the Internet from the personal computer 5 is inputted, normal data is based on the PID set in the demultiplexer 34, the CDMA code and the channel frequency data stored in the data memory 41. Transmit / receive operation is performed (ST8).

That is, according to the above embodiment, in the multimedia satellite communication system, the set top box 30 combines the unique PID distinguished from the other set top box 30 and the public PID received from the central station for the initial connection with the Internet in a contracted rule. After generating the connection PID, and then connecting to receive the information service data from the central station, the information service data is received using the generated connection PID.

Therefore, when receiving information service data from the central station, the connection PID generated through the contract rules between the central station and the corresponding set-top box is used, and then data is transmitted based on the information service data allocated from the central station, thereby securing the transmission data. It can be maintained.

In addition, this invention is not limited to the said Example, It can variously deform and implement within the range which does not deviate from the technical summary of this invention.

As described above, according to the present invention, when receiving information service data from the central station, the connection PID generated by the contract rule between the central station and the corresponding set-top box is used, and then the data is based on the information service data allocated from the central station. It is possible to realize the transmission data security maintenance method of the multimedia satellite communication system that can be transmitted to ensure the security of the transmission data.

Claims (1)

The central station is composed of TS packet and transmits data including CDMA code and channel frequency signal which is physically combined with the Internet and transmitted to the set-top box, and is connected to the control processing of the whole device based on the data allocated from the central station. In the multimedia satellite communication system having a set-top box for processing traffic with a communication terminal, A data storage step of storing the CDMA code and the channel frequency data received from the central station; Initial generation PID generation step of generating the initial connection PID by combining the unique PID of the set-top box and the common PID received from the central station in a contracted rule, An initial connection PID setting step of setting the initial connection PID in a demultiplexer, A control message sending step of generating a predetermined message including a unique PID of the set-top box based on the data stored in the data storing step and transmitting the predetermined message to the central station; An initial connection PID detection step of detecting initial connection PID information generated in the initial connection PID generation step from a control message received from a central station after the control message sending step; And a service information setting step of resetting the control PID and the traffic PID to the demultiplexer in the control message detected in the initial connection PID detection step, and storing the CDMA code and channel frequency information in the data memory. Transmission data security maintenance method of a multimedia satellite communication system.