KR100266789B1 - Method and device for preservating transmission data in multi satellite communication system - Google Patents

Abstract

PURPOSE: A method and a device for securing/maintaining transmission data of a multimedia satellite communication system are provided to maintain the security of data transmitted in an initialization process for connecting a communication terminal with the Internet. CONSTITUTION: A CDMA(Code Division Multiple Access) code and channel frequency data received from a central station are stored in a data memory(41), and a common PID(Process IDentifier) is stored in a demultiplexer(34). A call connection request with the Internet is received from a communication terminal. Predetermined terminal address data of a set top box, subscriber information inputted from the communication terminal and the common PID are read, to generate a predetermined information message. A control message is generated, and the CDMA code data and the channel frequency data are allocated to be delivered to the central station. A traffic PID is generated using a controlling PID received from the central station and predetermined terminal address data. The controlling PID, channel frequency, CDMA code and the traffic PID are reset for registration.

Description

Transmission data security maintaining method and apparatus for 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. In particular, in the initialization process of accessing the Internet through a multimedia satellite communication network, it is possible to maintain security of transmitted data. 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 every time the number of TS packets transmitted from the central station 1 to the set-top box 4 is reached at a predetermined interval.

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: address information 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).

In accordance with a first aspect of the present invention, there is provided a method for maintaining transmission data security of a multimedia satellite communication system. 10. A multimedia satellite communication system comprising a set-top box which executes traffic processing between a central station configured to transmit and a communication terminal connected to a control unit of the whole apparatus based on data allocated from the central station, and received from the central station. A data storage step of storing one CDMA code and channel frequency data in a predetermined memory and a common PID in a demultiplexer, a call connection request step of receiving a call connection request from the communication terminal with the Internet, and predetermined terminal address data of a set-top box. Subscriber information and public input from communication terminal with An information message generating step of reading a PID and generating a predetermined information message based thereon; an information message sending step of allocating the generated control message to the central station by allocating CDMA code data and channel frequency data; and a control PID received from the central station. A traffic PID generation step of generating a traffic PID using predetermined terminal address data of the set-top box, and a control PID, channel frequency, CDMA code received from the central station, and the traffic PID generated in the traffic PID generation step. Characterized in that it comprises a service information registration step of registering by resetting.

In addition, the transmission data security maintenance apparatus of the multimedia satellite communication system according to the second aspect of the present invention for achieving the above object is physically coupled to the Internet and configured to transmit the data to be sent to the set-top box as a TS packet, In the information message transmitted from the set-top box for the TS packet to be sent, a PID for traffic is generated based on the terminal address data, and the CDMA code data and channel frequency data to be used for the call connection with the control PID are transmitted to the set-top box. Based on this, a demodulator recovers original TS packet data from a center station for transmitting and receiving data with the set-top box, a tuner for converting a frequency signal received from the center station into an intermediate frequency, and an intermediate frequency output from the tuner. Means, a predetermined PI registered by the processor among TS packets inputted from the demodulation means A demultiplexer for receiving and outputting a TS packet having D, an interface card for connecting a communication terminal, CDMA channel transmitting means for CDMA modulating data to be transmitted to a central station using a predetermined CDMA code, and applying from the CDMA channel transmitting means Modulation means for frequency-modulating the data to be converted, intermediate frequency generating means for converting the frequency signal inputted from the modulation means to an intermediate frequency based on predetermined frequency data, and an address storing unique terminal address data distinguished from other set-top boxes. If there is an Internet connection request from the information storage unit and the communication terminal, the address information storage unit reads predetermined terminal address data and transmits the same to the central station, and thereafter, the control PID and the predetermined PID are received from the information message received from the central station. PID for traffic using terminal address data And a set-top box comprising a processor for executing and controlling the overall process of the apparatus and the traffic processing with the communication terminal based on the traffic PID and the control PID, CDMA code, and channel frequency assigned from the central station. It features.

That is, according to the present invention having the above-described configuration, when transmitting and receiving information data with the central station, by using the PID for traffic generated through the contract rules between the central station and the set-top box, it is possible to maintain the security of the transmission data The transmission data security maintaining method and the method of the multimedia satellite communication system can be realized.

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. RF device for frequency up-converting and amplifying the output of the intermediate frequency signal output from the high-frequency amplification, 32 is a tuner for outputting the intermediate frequency by converting the high-frequency signal output from the RF device 31, 33 is in this tuner 32 A demodulator for demodulating the output intermediate frequency signal, that is, the QPSK modulated signal, and outputting the TS packet data.

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 an address information storage unit for storing address information of the set-top box 30, and 43 is a processor for controlling the overall operation of the set-top box 30, which is the address information storage unit 42. Only a certain number of bits of the terminal address data stored in the terminal are read out, and a predetermined control message including the terminal address data is generated based on the common PID information and transmitted to the central station 1.

Subsequently, the control PID of the control message received from the central station 1 is combined with the terminal address data to generate a traffic PID, which is registered in the demultiplexer 34, and a predetermined CDMA code is received in the received control message. Then, the channel frequency data is stored in the data memory 41, and then the information data, that is, the control PID, the traffic PID, the CDMA code, and the channel frequency data are used for data transmission and reception with the central station.

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 an IP packet input from the Internet into the central station 1 into data of an Ethernet frame and converts the data 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 and the common PID is stored in the demultiplexer 34 (ST2).

Then, when the access request for the Internet, that is, the call connection request, is input from the personal computer 5 in the above state (ST3), the processor 43 sends a specific bit, e.g., 8 bits, from the address information storage section 42. The terminal address data is read out, and the subscriber information inputted through the 8-bit terminal address data and the network interface card 35, i.e., the subscriber ID, password, and subscriber address, is determined based on the initial access PID and the like. A control message is generated and transmitted to the transmission frame generation unit 36, and access information stored in the data memory 41, that is, CDMA code data and channel frequency data transmitted from the central station 1, are stored. By allocating to the CDMA channel transmitter 37 and the intermediate frequency generator 39, the access request is executed for the central station 1 (ST4 step).

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 assigned for the access. 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 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. It is determined whether the requesting subscriber is a legitimate subscriber.

At this time, if it is determined that the subscriber is a legitimate subscriber, the database 65 is searched to determine whether there is a PID currently available, and the control top, channel frequency, and CDMA code are assigned to the set-top box 30.

In addition, a 13-bit traffic PID is generated by using 5-bit PID data and 8-bit terminal address data received from the set-top box 30 among the control PIDs allocated to the set-top box 30 and transmitted together with the allocation information. The data is stored in the data processing device 57. Subsequently, the central international language processor 63 generates an Ethernet frame for transmitting the control PID, the channel frequency data, and the CDMA code among the PID information, and transmits the Ethernet frame to the transmission data processing apparatus 57 through the IP switch 50. The transmission data 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.

On the other hand, in the set-top box 30, the processor 43 receives the information message of the TS packet transmitted from the central station 1 through the RF device 31, the tuner 32 and the demodulator 33 (Step ST5), the received information message is applied to the demultiplexer 34 to mask only the header portion of the information message, that is, the portion including the PID for a predetermined bit, and is stored in the demultiplexer 34 among the received information messages. Only the information message matching the connection PID is received and processed.

That is, in the information message in which the connection PID is matched, the CDMA code and channel frequency data allocated from the central station 1 are transmitted to the CDMA channel transmitter 37 and the intermediate frequency generator 39, and the received control. The PID for traffic is generated by using specific 8-bit data among the PID and the terminal address data stored in the address information storage 42 (ST6).

Subsequently, the processor 43 registers the new service information by resetting the control PID allocated from the central station 1 and the PID for traffic generated by the prescribed rule to the demultiplexer 34 (ST7). Then, the personal computer 5 is notified of the successful call connection through the network interface card 35.

Subsequently, when an IP packet for transmitting to the Internet from the personal computer 5 is input, the network interface card 35 converts it into an Ethernet packet and inputs it to the processor 43. The processor 43 then converts the packet into an IP packet. By converting and outputting the data to the transmission frame generator 36, the corresponding traffic data is transmitted to the central station 1.

That is, according to the above embodiment, when there is a call connection request for the Internet from the personal computer 5 coupled to the set-top box 30 in the multimedia satellite communication system, the terminal station data stored in the set-top box 30 is transferred to the central station ( 1), and then generate a traffic PID using the control PID and predetermined terminal address data transmitted from the central station 1, and then use the traffic PID generated by the above-described method when transmitting data from the central station 1 later. Will be used.

Therefore, when transmitting and receiving data with the central station, by using the traffic PID generated through the contract rules between the central station and the set-top box, it is possible to maintain the security of the transmission data.

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 transmitting and receiving data with the central station, the multimedia satellite communication system is able to maintain the security of transmission data by using the PID for traffic generated through the contract rules between the central station and the set-top box. The transmission data security maintaining method and apparatus can be realized.

Claims (3)

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 storing step of storing the CDMA code and the channel frequency data received from the central station in a predetermined memory and storing the common PID in a demultiplexer; A call connection request step of receiving a call connection request with the Internet from the communication terminal, An information message generation step of reading a predetermined terminal address data of the set-top box and subscriber information and a common PID inputted from the communication terminal, and generating a predetermined information message based on this; An information message sending step of transmitting the generated control message to the central station by allocating CDMA code data and channel frequency data; A traffic PID generation step of generating a traffic PID using the control PID received from the central station and predetermined terminal address data of the set-top box, and And a service information registration step of resetting and registering the control PID, channel frequency, CDMA code received from the central station, and the traffic PID generated in the traffic PID generation step. How to keep your data secure. Physically combined with the Internet, TS packets are composed of the data to be transmitted to the set-top box, and the PID for traffic is generated based on the terminal address data in the information message transmitted from the set-top box for the TS packet to be transmitted. And a central station transmitting and receiving CDMA code data and channel frequency data to be used in connection with a control PID to the set-top box, and transmitting and receiving data with the set-top box. A tuner for converting a frequency signal received from the central station into an intermediate frequency, demodulation means for restoring original TS packet data from an intermediate frequency output from the tuner, and a TS packet input from the demodulation means registered by a processor; A demultiplexer for receiving and outputting a TS packet having a predetermined PID, an interface card for connecting a communication terminal, a CDMA channel transmitting means for CDMA modulating data to be transmitted to a central station using a predetermined CDMA code, and the CDMA channel transmitting means Modulation means for frequency-modulating the data applied from the apparatus, intermediate frequency generating means for converting the frequency signal inputted from the modulation means to the intermediate frequency based on predetermined frequency data, and unique terminal address data distinguished from other set-top boxes are stored Address information storage unit and the communication terminal If there is an Internet connection request from the mobile station, the address information storage unit reads predetermined terminal address data and transmits it to the central station, and then uses the control PID and the predetermined terminal address data in the information message received from the central station. A set-top box including a processor for generating a PID for the traffic and executing and controlling the overall processing of the device and the traffic processing with the communication terminal based on the PID for the traffic, the control PID, the CDMA code, and the channel frequency allocated from the central station. Transmission data security maintenance device of a multimedia satellite communication system, characterized in that it comprises. The method of claim 1, The PID generation step for traffic reads a predetermined 8-bit data of the terminal address data of the set-top box by a prescribed method with the central station, and reads and synthesizes 5 bits of the control PID data transmitted from the central station to synthesize 13-bit traffic. Transmission data security maintenance method of a multimedia satellite communication system, characterized in that for generating a PID.

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