KR0173009B1 - Video on demand metwork system - Google Patents

Abstract

The present invention relates to a service that gives users maximum choice of compressed moving picture digital video data, and can make and receive phone calls while watching a video, and also called a narrowband integrated services digital network (ISDN). The present invention relates to an on-demand video network system that can simultaneously provide a service. In the conventional implementation of an on-demand video network system, an asymmetric digital subscribing line (ADSL) method was used because the medium of the subscriber network was a telephone line. In this case, the VOD service and the telephone call service can be simultaneously performed on a single line, but a repeater is necessary to compensate for the signal attenuation characteristic of the telephone line, and an ADSL type modem is expensive, causing problems that are not economical. Subscriber Solves the problem of signal degradation and maintenance by using optical fiber as a medium, and modulates a telephone signal into a digital signal, and then transmits and receives a digital signal using a full digital method by time division multiplexing (TDM). Voice signals for subscribers can also be digitally bi-directionally communicated, ISDN service is possible, and at the same time, the transmission path using fiber optic cable enables moving picture digital video service, eliminating service restrictions due to increased bandwidth. Enable evolution to future video and information communication.

Description

Custom Video Network Systems

1 is a configuration block diagram of a user-customized video network system of the present invention.

2 is another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: Switch 2, 22: B channel matching part

3, 21: 2B + D channel matching unit 4: 2B + D channel mapper / demapper

5: B channel mapper / demapper 6: System synchronous clock generator

7-9, 18-20: 51M Framer / Reframer

10: video server 11: distribution switch

12, 12A, 12B: 45M multiplexer

13, 23: maintenance and video signal matching unit

14, 17: 155M optical transmission unit 15: optical fiber cable

16: spool litter 24: 45M demultiplexer

25-1: Video Processing 1 Decoder 25-2: Anti-Sushi Encoder

25A: Video Processing 2 Decoder 26: ISDN Phone

27: regular telephone 28: TV

30: distribution device 40: subscriber device

The present invention relates to a service that gives users maximum choice of compressed moving picture digital video data, and can make and receive phone calls while watching a video, and also called a narrowband integrated services digital network (ISDN). The present invention relates to an on-demand video network system that can be provided at the same time.

It can be used in the core technology fields of interactive interactive service and future video information communication.

In the conventional method of implementing a demand-demand video network system, since the medium of the subscriber network is a telephone line, an asymmetric digital transmission and reception of data using frequency division multiplexing (FDM) is necessary to simultaneously make and receive a video while watching a video. We had to use the Asymmetrical Digital Subscriber Line (ADSL).

However, each channel of an asymmetric digital subscriber line (ADSL), that is, a one-way channel to a subscriber, a two-way channel for a control signal, and a telephone channel for a telephone exchange, is demodulated with different frequency bandwidths, so that the demand-demand video on a single line (Video On Demand: hereinafter referred to as VOD) Service and telephone call service are possible at the same time, but a repeater is necessary to compensate for the signal attenuation characteristics of the telephone line. In addition, the price of the ADSL-based modem used is expensive and not economical.

These points make it difficult for the prior art system to evolve into interactive interactive television service, which will be the core of future video information communication.

Accordingly, in order to solve the above problems, the present invention solves the problems of signal degradation and maintenance by using a medium of a subscriber network as an optical fiber, modulates a telephone signal into a digital signal, and then performs time division multiplexing with a digital video signal. Time Division Multiplexing (TDM) is used to transmit and receive using a full digital (Full Digital) method is characterized in that the service restriction due to the increase of bandwidth is almost eliminated and the evolution to the future video information communication is possible.

In other words, the configuration of the user-demand video network system of the present invention reconstructs a general telephone service from an exchange of a telephone station to 2 Mbps, which is a basic format of a digital transmission scheme, for a B-channel signal as an analog signal and a 2B + D channel signal for a narrowband ISDN service. 2B + D channel mapper / demapper and B channel mapper for inputting signals of the B channel matching unit and the 2B + D channel matching unit, and the B channel matching unit and the 2B + D channel matching unit, respectively, and outputting them by a time switching method. / Demapper, a system synchronous clock generator for generating a clock for synchronizing a transmitted and received signal, and video data output through several output ports of a video server storing compressed video data. 45M multiplexing for multiplexing the distribution switch for connecting and multiplexing the video data inputted by the distribution switch into 12 subscribers A maintenance and video signal matching unit for inputting and outputting a video channel signal desired by the subscriber to the video server and maintaining the respective circuits; and the 2B + D channel mapper / demapper and the B channel mapper in the case of downlink data. Synchronous Transport Signal level-1 (STS-1) data, which is a multiplexing structure of the Plesiochronous Digital Hierarchy (PDH), by inputting data from the / demapper and 45M multiplexer. Standardized and uplink data, the data regarding the ISDN, landline, and video channel selection signals received from the subscriber are stored in the 2B + D channel mapper / demapper and B-channel mapper / demapper and maintenance and video signals through an overhead passage. Each 51M framer / reframer outputs to the matching section, and each of the three synchronous transmission signal-1 (STS-1) data in case of downlink data. Converts an electrical signal to an optical signal while converting it into a synchronous transmission module level-1 (STM-1) data stream using an inter-division multiplexing (TDM) scheme, and inverting the data into three data in the case of upstream data. A distribution device comprising a 155M optical transmitter for multiplexing and outputting a subscriber selection signal to each 51M framer / reframer; The data output from the distribution device is input through an optical fiber cable to convert the distributed data into an electrical signal for sharing by 12 subscribers in the splitter, and then demultiplexed into three bit stream data, and in the case of upstream data, into an optical signal. The 155M optical transmitter converts one data stream into a splitter and outputs the data to the splitter, and transmits data to and from the 155M optical transmitter using overhead bits, up-down data of 2B + D channel ISDN and 12 subscribers of a general telephone. Each 51M framer / reframer that is responsible for the passage of video downstream data for VOD of a 12-bit bit stream, and an S interface for transmitting and receiving data for 1 subscriber of ISDN up-down data for 12 subscribers to an ISDN telephone. 2B + D channel matching unit in charge, and digital subscriber for 12 subscribers After selecting voice data for one subscriber, converting to analog, B channel matching unit in charge of the tip / ring interface and the video downstream data for VOD are demultiplexed to decode the video data for one subscriber. A 45M demultiplexer for outputting, a Moving Picture Experts Group 1 (MPEG1) decoder which inputs data of the 45M demultiplexer and decompresses the data, and a television signal transmitted from the video processor 1 decoder. A National Television System Committee (NTSC) encoder that converts a digital television subscriber to watch video on television, and maintains the up-down interface and video channel selection upstream data interface for maintenance of the circuits. Subscriber device consisting of maintenance and video signal matching unit It is.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a schematic diagram of a system of the present invention.

Distribution device 30 for distributing narrowband ISDN 2B + D channels input from switch 1, B channel for general telephone service and video channel for VOD, and data from distribution device 30 for optical fiber cable 15 The splitter 16 is distributed to each subscriber to share through the subscriber device 40 to provide a service to the subscriber. The main feature of this system is that it enables the use of telephone and narrowband ISDN service while watching the subscriber's required video.

First, the configuration of the distribution device is as follows.

B channel matching unit 2 and 2B + which reconstruct B channel signal, which is an analog signal for general telephone service, and 2B + D channel signal for narrowband ISDN service, to 2Mbps, which is the basic format of digital transmission method, from exchange 1 2B + D channel mapper / demapper 4 for inputting signals of the D channel matching section 3, the B channel matching section 2, and the 2B + D channel matching section 3, respectively, and outputting them in a time switching method. And a plurality of outputs of the B-channel mapper / demapper 5, a system synchronous clock generator 6 for generating a clock for synchronizing signals transmitted and received, and a video server 10 for storing compressed moving picture digital video data. A distribution switch 11 for connecting subscribers by inputting video data output through a port, a 45M multiplexer 12 for multiplexing the video data inputted by the distribution switch 11 into 12 subscribers, and Input the desired video channel signal And a video signal matching unit 13 for maintaining each component circuit while outputting to the video server 10, and the 2B + D channel mapper / demapper 4 and the B channel mapper / de Input data from the mapper 3 and the 45M multiplexer 12, and standardize to three synchronous transmission signal-1 (STS-1) data, which is a multi-synchronized hierarchical (PDH) type structure, and the ISDN received from the subscriber in the case of uplink data. The 2B + D channel mapper / demapper 4 and the B channel mapper / demapper 5 and the maintenance and video signal matching unit 13 through the overhead passage for data related to general telephone and video channel selection signals. Time division multiplexing (TDM) of each 51M framer / reframer (7) (8) (9) that outputs to The synchronous transmission module-1 (STM-1) data stream The 155M optical transmitter 14 converts an electrical signal into an optical signal and demultiplexes the data into three data in order to output a subscriber selection signal to each 51M framer / reframer (7) (8) (9). It is made, including.

Next, the configuration of the subscriber device will be described.

The data output from the distribution device 30 is input through the optical fiber cable 15 to convert the distributed data into an electrical signal for sharing by 12 subscribers in the splitter 16 and then demultiplexed into 3 bit stream data. In the case of uplink data, the 155M optical transmitter 17 converts an optical signal into one data stream and outputs the data to the splitter 16, and transmits and receives data to and from the 155M optical transmitter 17. Each 51M framer / reframer (18) (19) (20), which is responsible for the passage of 2B + D channel ISDN and upstream and downstream data for 12 subscribers and video downstream data for VOD of 12 bitstreams And 2B + D channel matching unit 21, which is in charge of the S interface for transmitting and receiving the data for one subscriber among the up and down data for ISDN for 12 subscribers, to the ISDN telephone 26, and the 12 subscriptions. One channel subscriber's digital voice data for one subscriber is selected and converted into analog, and the B-channel matching unit 22 in charge of the tip / ring interface and the video downstream data for the VOD are inputted. 45M demultiplexer 24 which outputs video data for one subscriber after multiplexing, and moving picture processing 1 (MPEG1) decoder 25-1 which decompresses data by inputting data of the 45M demultiplexer 24. And an NTSC encoder 25-2 which converts a television signal transmitted from the moving image processing 1 decoder 25-1 into an analog signal so that a general television subscriber can watch a video through the television 28. And a maintenance and video signal matching unit 23 which is responsible for the maintenance-related up and down interface and the video channel selection upstream data interface of the circuits.

The operation of the configuration as described above is as follows.

The B channel matching unit 2 converts the analog signal of the ordinary telephone into a digital signal and receives the B and 2B + D channels for the general telephone and narrowband ISDN service from the switch 1, which is a basic format of digital transmission. Reconfigure with 2Mbps CEPT (European Conference on Pots and Telecommunication) structure. In the case of upstream data from the subscriber, the digital signal is converted into an analog signal and sent to the exchange 1. At this time, the clock of the system synchronization clock generator 6 is synchronized. On the other hand, the 2B + D channel matching unit 3 reconstructs the ISDN signal for the 2B + D channel received from the switch 1 into the system synchronization clock generator 6 in a 2Mbps CEPT structure. Then, each signal is input to the 2B + D channel and the B-channel mapper / demapper (4) (5), which uses the time switching to downlink the signals for the B-channel and 2B + D channel corresponding to the subscriber. In the case of transmitting data to the framer side of each 51M framer / reframer (7) (8), and in the case of the upstream data, each subscriber-specific data supplied from the leafer side of the 51M framer / reframer (7) (8) is transmitted. It is completely mounted in 30 time slots in a 2 Mbps CEPT structure and transmitted to the B channel matching section 2 and the 2B + D channel matching section 3.

The video server 10, which stores 1.5 Mbps of moving picture digital video data, includes server and system-wide maintenance, input / output ports, bit rate control of moving picture video data output, and a video disk array. It is the distribution switch 11 that connects the output port of the video server and the 45Mbps multiplexer 12. One of its important roles is to centralize and efficiently use the server to perform economic benefits. At this time, the video channel signal desired by the subscriber passes through the maintenance and video signal matching unit 13 through the 64 Kbps overhead passage inside the leaf reamer of the 51M framer / reframer 9 and then is input to the video server 10. . The video server 10 outputs the selected video data through the input / output port to the distribution switch 11 and simultaneously connects a circuit passage corresponding to the subscriber. The 45M multiplexer 12 that inputs the video data by the distribution switch 11 has a framer basic input bitrate of 51M framer / reframer 9 whose data stream is 44.736 Mbps in the multi-structure of the PDH method. It is for multiplexing up to 28 1.5 Mbps of digital video data of the video server 10 because it is an digital signal 3 (Digital Signal 3: DS3). In this system, since 12 subscribers are a basic unit, the 45M multiplexer 12 multiplexes only 12 subscribers.

The 155M optical transmission unit 14 uses three time division multiplexing (TDM) schemes for three 51.84 Mbps of synchronous transmission signal-1 (STS-1) data of each 51M framer / reframer (7) (8) (9). The electrical signal is converted into an optical signal while being converted into a synchronous transmission module-1 (STM-1) data stream. The reason why the 155M optical transmitter 14 multiplexes the 155.52 Mbps data stream is to unify the user network interface (UN) speed of 155.52 Mbps of the Broadband IDSN (B-ISDN). It is also based on 155.52 Mbps because of its compatibility with the synchronous hierarchy (SDH) base interface, which is one of the broadband ISDN (B-ISDN) interface structures.

As described above, the data transmitted from the distribution device 30 is input to the subscriber device 40 through the optical fiber cable 15, before the splitter 16 distributes 155.52 Mbps of data to 12 subscribers. do.

Thereafter, the data inputted to the subscriber device 40 is inputted to the 155M optical transmitter 17 to be converted into an electrical signal and demultiplexed into three 51.84 Mbps bitstream data. The demultiplexed data is input to a leaframer of 51M framer / reframer 18, 19, 20, respectively, with the leaframer of 44.736 Mbps of digital signal 3 (DS3) and payload of 2 Mbps and 64 Kbps. It consists of overhead bits. ISDN up / down data of 2B + D channel for 12 subscribers, normal phone up / down data of B channel, and video down data for VOD of 1.5 Mbps bitstream are respectively stored in 51M framer / reframer (18) (19) (20). It is transmitted via the framer's 2Mbps overhead bit.

The 12 subscriber's ISDN up and down data is transmitted to the ISDN telephone 26 as 1 subscriber's data through the 192 Kbps S interface of the 2B + D channel matching unit 21. In addition, the digital voice data having the 2Mbps CEPT structure for the general telephone subscriber is also transmitted to the general telephone 27 through a tip / ring (T / R) interface of the B channel matching unit 22. In this case, the digital voice signal is converted into analog and then transmitted. The VOD video downlink data is input to the 45M demultiplexer 24 and demultiplexed. Then, it is transmitted to the moving image processing 1 (MPEG1) decoder 25-1 as video data for one subscriber. The moving picture processing 1 (MPEG1) decoder 25-1 decompresses the data and sends it to the NTSC encoder 25-2. At this time, the NTSC encoder 25-2 converts a television signal transmitted as a digital signal into an analog signal so that a general television subscriber can watch a video.

On the other hand, the uplink data from the ISDN telephone 26 is 2 Mbps of the framer overhead bits of the 51M framer / reframer 18, and the uplink data of the general telephone subscriber is the framer overhead bit of the 51M framer / reframer 19. Medium 2 Mbps path and data related to video selection and maintenance of subscriber device 40 are loaded on each framer using 64 Kbps path of framer overhead bits of 51M framer / reframer 20, and then 155M optical transmitter Multiplexed at 17, and then passed to switch 1 and video server 10. FIG.

2 is another embodiment of the present invention, two 45M multiplexer for multiplexing the video data in the distribution device 30 so that the data stream of moving picture digital video data can accommodate 6 Mbps of moving picture processing 2 (MPEG2) (12A, 12B) to multiplex each of 6 subscribers so as to be multiplexed into 12 subscribers in total, and accordingly, the moving picture processing 1 (MPEG1) decoder 25-1 of the subscriber device 40 is moved to the moving picture processing 2 ( MPEG2) decoder 25A. Since the data bit stream of the 155.52 Mbps optical subscriber network accommodates 12 subscribers, 45M multiplexing which multiplexes 6 Mbps of moving picture digital video data of 6 Mbps moving image processing 2 (MPEG2) into 12 subscribers is multiplexed into 6 subscribers, respectively. It must be fitted with two additional parts (12A, 12B). As a result, a total of 12 subscriber moving picture digital video data is supplied to the subscriber network by two 45M multiplexers 12A and 12B which multiplex the moving picture digital video data into six subscribers.

As described above, according to the present invention, voice signals for general telephone subscribers can be digitally bi-directionally communicated, ISDN service is possible, and at the same time, a digital video service is also possible because a transmission path is implemented using a fiber optic cable. Done.

Claims (2)

In constructing an on-demand video network system, the B-channel matching unit 2 for reconstructing the B-channel signal for telephone service input from the switch 1 and the 2B + D channel signal for narrowband ISDN service to 2Mbps; 2B + D channel mapper / demapper for mapping and outputting signals from the 2B + D channel matching unit 3 and the 2B + D channel matching unit 3 and the B channel matching unit 2 according to time switches ( 4) and the B-channel mapper / demapper 5, the system synchronous clock generator 6 for generating a clock for synchronizing the transmission and reception signals, and the compressed moving picture digital video data output from the video server 10. To the video server 10, a distribution switch 11 for connecting to the network, a 45M multiplexer 12 for multiplexing the video data inputted by the distribution switch 11 in units of 12 subscribers, and a subscriber's video channel selection signal to the video server 10. Output and maintain each component circuit The downlink data of the maintenance and video signal matching section 13, the 2B + D channel mapper / demapper 4, the B channel mapper / demapper 5, and the 45M multiplexer 12; The 2B + D channel mapper / demapper 4 and the B channel mapper / demapper are standardized into three pieces of data, and the respective uplink data for the telephone, ISDN, and video channel selection signals transmitted from the subscriber are transmitted through an overhead passage. (5) and the synchronous transmission signal-1 data 3 of each 51M framer / reframer 7-9 and the 51M framer / reframer 7-9 outputted to the maintenance and video signal matching section 13; It converts the dog into a synchronous transmission module-1 data stream through time division multiplexing and transmits it as an optical signal, and demultiplexes the upstream data transmitted from the subscriber into three data for telephone, ISDN and video channel selection signals. With reframer (7-9) Dispensing device 30 comprises a 155M optical transmission section 14, which force and; The downlink data output from the distribution device 30 is input through the optical fiber cable 15 to convert the data distributed by the splitter 16 to be shared by 12 subscribers into an electrical signal and then demultiplexed into three bit stream data. The 155M optical transmitter 17 converts the upstream data from the subscriber into an optical signal and converts the data into a single data stream and outputs the data to the splitter 16. The overhead bit is transmitted and received with the 155M optical transmitter 17. Each 51M framer / reframer (18 to 20), which is responsible for the passage of up-down data in 12-bit subscriber units and 12-bit bit stream video downlink data in 12-subscriber unit ISDN and general telephone, using 2B + D channel matching unit 21 for outputting ISDN data in a single subscriber unit input through the 51M framer / reframer 18 to the ISDN telephone 26, and the 51M framer / Input via the 51M framer / framer 20 and the B-channel matching unit 22 for converting the digital voice data of a single subscriber unit input through the framer 19 into an analog signal and outputting the analog signal to the ordinary telephone 27. A 45M demultiplexer 24 for demultiplexing the VOD video downlink data and outputting video data in units of subscribers, an MPEG1 decoder 25-1 for decoding the data of the 45M demultiplexer 24; And an NTSC encoder 25-2 for converting the television signal of the MPEG1 decoder 25-1 into an analog signal for viewing through the TV 28, and maintaining and maintaining the up and down interface associated with the maintenance of the configuration circuits and the video channel. And a subscriber unit (40) comprising a maintenance and video signal matching unit (23) for the selective upstream data interface. The decoder for decoding the demultiplexed moving picture digital video data in the 45M demultiplexing unit 24 of the subscriber device 40 is an MPEG2 decoder 25A, and the moving picture digital video is distributed in the distribution device 30. An on-demand video network system comprising two 45M multiplexers (12A) and 12B for multiplexing data on a six-member basis.