CN1117453C

CN1117453C - Data broadcast system of digital vedio broadcast

Info

Publication number: CN1117453C
Application number: CN99100833A
Authority: CN
Inventors: 李建华; 侯自强; 王劲林; 程钢; 肖孙圣; 曹晓军; 辛宇
Original assignee: Institute of Acoustics CAS
Current assignee: Institute of Acoustics CAS
Priority date: 1999-02-24
Filing date: 1999-02-24
Publication date: 2003-08-06
Anticipated expiration: 2019-02-24
Also published as: CN1264976A

Abstract

The invention relates to a multimedia information communication technology, which mainly includes: an Internet gateway, a data broadcast server, a multiplexer, a quadrature amplitude modulator, a remote access server and a user terminal. The invention can utilize the channel transmission technology of digital video broadcasting to transmit data service in the channel of digital video broadcasting, combine digital TV broadcasting and multimedia data broadcasting, and provide multifunctional services on cable TV network.

Description

The Radio Data System of digital video broadcasting

The invention belongs to the multi-media information communication technical field.Relate in particular to the broadcast system of digital video broadcasting.

At present some occur and be used for the Radio Data System of cable TV network.For example, the Radio Data System of Tsing-Hua University's exploitation (seeing the propaganda materials " based on the outer interactive multimedia digital data broadcast system of CATV net " of Yongxin of Tsing-Hua University Information Technology Co. Ltd), several cable TVs were at home done transmission experiment on the net.Its downlink transfer has adopted the QPSK modulation technique, and the message transmission rate on the bandwidth (8M) of a pal mode is 10Mbps.The analog bandwidth of current cable 8MHz is divided into the subband of 4 2MHz, with data-modulated in the passband of 2MHz.Receiving terminal adopts computer card.But these systems adopt special data format and transmission means, and transmission speed is slow, and function singleness is unfavorable for carrying out multifunctional service and other network interconnection difficulties.

The objective of the invention is to propose a kind of Radio Data System of the digital video broadcasting of forming by internet (Internet) gateway, digital video broadcasting (DVB) broadcast data server, multiplexer, quadrature amplitude modulation (QAM) modulator and RAS, it is connected with the internet easily, the integrated digital video broadcast system, do not increase the burden of existing network, thereby solved the problem that prior art exists.

Basic thought of the present invention is, the information service front end is broadcast mass data in the circulation of DVB channel high speed, and the user selects to accept oneself needed data from these data.It is felt to be similar to and is using the browser access World Wide Web (WWW) on the internet.If the user needs the other guide beyond the loop-around data, can front end be delivered in request by telephone wire, come from the internet with required data retrieval by front end, from broadcast channel, broadcast away again.

Therefore, the technical solution adopted in the present invention is that it includes internet gateway, DVB broadcast data server, multiplexer, quadrature amplitude modulation (QAM) modulator and RAS and user terminal.Wherein:

The data broadcasting service front end is provided with internet gateway, DVB broadcast data server, multiplexer, quadrature amplitude modulation (QAM) modulator and RAS at its front end.Internet gateway links to each other by local area network (LAN) with DVB broadcast data server, RAS three, internet gateway links to each other with the internet simultaneously, it receives the user data requests of sending here by RAS, from the internet, fetch the needed data of user according to user's requirement, and give DVB broadcast data server by local area network (LAN) the data of fetching.After the DVB broadcast data server is received the data that internet gateway sends here, code stream call format according to digital video broadcasting (DVB), data are squeezed in the code stream of DVB, interface standard according to the transport stream (TS) of DVB regulation is given multiplexer (MUX) with data, multiplexer forms data code flow and the multiplexing back of other video/audio code stream the code stream of higher rate, speed can reach 20 to 40Mbps (megabit per seconds), this high-speeld code-flow is still given the modulator of quadrature amplitude modulator (QAM) or alternate manner according to the interface standard of the transport stream (TS) of DVB regulation, this modulator is modulated to analog radio frequency (RF) signal with data code flow and sends in the cable TV network and transmit.Have data broadcasting and accept in the subscriber computer top box access cable TV network of function the data code flow of broadcasting to be accepted to give household PC by network interface, household PC can be consulted data information by explorer; Perhaps set-top box is given built-in TV browser with data, consults data on television set.If the user needs other data of not broadcasting, can use the interior telephone modem (Modem) of set-top box request of data to be given the RAS of front end by public phone network.So just constituted a Radio Data System based on DVB.

The invention has the advantages that it meets the DVB standard, adopt TCP/IP (transmission control and the internetworking) agreement of Internet Standard, be connected with the internet easily, the compatible with DVB digital video broadcasting does not increase the burden of existing network, small investment, instant effect.

Fig. 1 is data flow architecture figure;

Fig. 2 is a system construction drawing;

Fig. 3 is index structure figure;

Fig. 4 is the set-top box structure chart;

Further specify preferred embodiment of the present invention in conjunction with above-mentioned each accompanying drawing now.

As shown in Figure 2, the present invention mainly includes internet (Internet) gateway 2, DVB broadcast data server 3, multiplexer 4, quadrature amplitude modulation (QAM) modulator 5 and RAS 6 and user terminal.At the data broadcasting service front end, internet (Internet) gateway 2, DVB broadcast data server 3, multiplexer 4, quadrature amplitude modulation (QAM) modulator 5 and RAS 6 are set.Internet gateway 2 links to each other by local area network (LAN) (10/100Mbps Ethernet) with DVB broadcast data server 3, RAS 6 threes, internet gateway 2 links to each other with internet 1 simultaneously, it receives the user data requests of sending here by RAS 6, from the internet, fetch the needed data of user according to user's requirement, and give DVB broadcast data server 3 by local area network (LAN) the data of fetching.After DVB broadcast data server 3 is received the data that internet gateway 2 sends here, code stream call format according to digital video broadcasting (DVB), data are squeezed in the code stream of DVB, interface standard according to the transport stream (TS) of DVB regulation is given multiplexer 4 (MUX) with data, multiplexer 4 forms data code flow and the multiplexing back of other video/audio code stream the code stream of higher rate, speed can reach 20 to 40Mbps (megabit per seconds), this high-speeld code-flow is still given the modulator of quadrature amplitude modulator 5 (QAM) or alternate manner according to the interface standard of the transport stream (TS) of DVB regulation, this modulator 5 is modulated to analog radio frequency (RF) signal with data code flow and sends into transmission in the cable TV network 7.Have data broadcasting and accept in the subscriber computer top box 9 access cable TV networks 7 of function the data code flow of broadcasting to be accepted to give household PC 11 by network interface, household PC 11 can be consulted data information by explorer; Perhaps set-top box 9 is given built-in TV browser 10 with data, consults data on television set.If the user needs other data of not broadcasting, can use set-top box 9 interior telephone modems (Modem) request of data to be given the RAS 6 of front end by public phone network 8.So just constituted a Radio Data System based on DVB.

In Fig. 2, utilize the DVB channel at cable TV online 7, the high-speed datacasting business is provided on unidirectional broadcast network, playing application can be one-way broadcast systems such as cable TV network.The information service front end is broadcast mass data in the circulation of DVB channel high speed, and the user selects to accept own needed data from these data.It is felt to be similar to and is using the browser access World Wide Web (WWW) on the internet.If the user needs the other guide beyond the loop-around data, can front end be delivered in request by telephone wire, come from the internet with required data retrieval by front end, from broadcast channel, broadcast away again.

As shown in Figure 1, with one piece of data tandem array loop play, as luggage on the conveyer belt of airport.The user can download each cycle of selecting that mostly is circulation blanking time most from wherein selecting own required part to receive.The time in cycle can be selected arbitrarily.For example: when transmission rate was 40Mbps, it was 5Gbyte (gigabyte) data that 1000 second time interval can be transmitted 40Gbit (lucky position).The user selects the data that oneself needs in the data of 5Gbyte, each stand-by period mostly is 17 minutes most.

In the middle of the initial sum of the data flow of broadcasting, insert the content retrieval catalogue several times, as shown in Figure 3.Can receive the content retrieval catalogue as early as possible after user's start, the user chooses required content by the content retrieval catalogue, and its stand-by period mostly is the cycle of circulation most.

The user uses the device of unifying with Digital Television DVB set-top box to receive data broadcasting.Only need suitably to increase the function of CPU (CPU) and the capacity of internal memory, other parts can be shared, and the cost increase seldom.As shown in Figure 4.Subscriber computer top box 9 comprises: modules such as network interface 13, channel-decoding 14, deciphering 15, demultiplexing 16, read-only memory 17, CPU 18, random access storage device 19, Ethernet unit 20, remote control unit 21, graphic element 22, A/V coding 23 are formed.Network interface 13 is link blocks of subscriber computer top box 9 and cable television network 7, finishes the function of tuning demodulation.Channel-decoding 14, deciphering 15 and demultiplexing 16 are used to handle the code stream information of DVB.Ethernet unit 20 is used for and being connected of household PC.

Claims

1. A data broadcasting system for digital video broadcasting, characterized in that it includes: Internet gateway, DVB data broadcasting server, multiplexer, quadrature amplitude modulation modulator and remote access server and user terminal, wherein;

Internet gateway, which is connected to the data broadcast server and the remote access server through the local area network, and it is also connected to the Internet;

The data broadcasting server, which receives data from the Internet, transmits the data to the multiplexer according to the standard interface of the transport stream stipulated by DVB according to the code stream format requirements of the data video broadcasting;

A multiplexer, which multiplexes the data code stream and other video code streams to form a high-speed code stream and transmits it to the quadrature amplitude modulator or other modulators according to the standard specified by DVB;

Quadrature amplitude modulator, which modulates the data code stream into an analog radio frequency signal and sends it to the cable TV network;

A subscriber terminal, which is connected to the cable television network.

2. The data broadcasting system according to claim 1, characterized in that said user terminal includes: network interface, channel decoding, decryption, demultiplexing, read-only memory, central processing unit, random access memory, It is composed of Ethernet unit, remote control unit, graphics unit, A/V encoding and other modules.

3. The data broadcasting system according to claim 1, characterized in that said DVB data broadcasting server, the data code stream it produces periodically circulates, and the cycle period can be selected arbitrarily, and the user's waiting time is the longest cycle period.

4, by the described data broadcast system of claim 1, it is characterized in that said DVB data broadcast server, the data code stream that it produces contains directory retrieval information, and the user set-top box can be told from the code stream according to the directory retrieval information Pick the desired information.

5, by the described data broadcasting system of claim 1, it is characterized in that described user terminal, the user uses and digital TV DVB set-top box unites the device to receive data broadcasting, only needs to increase the function of CPU and the capacity of internal memory appropriately , other parts can be shared.