JPH04275792A - Data information communication system for optical wave length multiplex bindirectional catv telephone - Google Patents

Abstract

PURPOSE:To drastically increase the channel band on a transmission line, and achieve the transmission of massive data by converting and multiplexing information for every information source into optical signals with different wave length and transmitting the information with optical transmission. CONSTITUTION:A time division multiplexer 5 converts and multiplexes every output signal from an information supply device 1, a television program replay device 2, a self-broadcasting device 3 and a telephone data interface device 4. An optical signal converter 6 converts the converted information into optical signals with different wave length for every information source. An optical wave length multiplexer 7 multiplexes the optical signals with converted wave length to transmit to an optical transmission line 40. A spectroscope device 10 optically separates the multiplexed optical signals, restores them for every information source on the transmission side, selects among them only those with a necessary wave length to convert into digital signals of a single wave length and outputs it to a telephone data terminal 11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way CATV telephone data information communication system, and more particularly to an optical wavelength multiplex conversion system.

0002

[Prior Art] A conventional two-way CATV network is
The signal multiplexing method in the CATV network uses FDM (Free
Quency Division Mnltipl
One uplink channel and one downlink channel of the FDM multiplexed TV channels were used as a pair for telephone calls.

FIG. 3 is a diagram showing an overview of the channel configuration of a conventional CATV network.
Upstream and downstream signals are separated, and one TV channel is allocated for telephone calls, with a bandwidth of 6MHz.

0004

[Problem to be solved by the invention] Conventional two-way CATV
The network uses FDM (Freq
uency Division Mnltiple
TV
It is necessary to allocate a bandwidth of 6 MHz to each channel, and since the frequency band is finite, there is concern that there will be a shortage of channels if the amount of information transmission increases.

An object of the present invention is to use an optical fiber transmission line for signal transmission and reception between an information center and subscribers, and to convert each information source into an optical signal with a different wavelength, multiplex it, and transmit it. An object of the present invention is to provide an optical wavelength division multiplexing bidirectional CATV telephone data information communication system that has an increased channel band and is capable of transmitting a large amount of data.

[0006]

[Means for Solving the Problems] The optical wavelength division multiplexing bidirectional CATV telephone data information communication system of the present invention includes an information providing device for providing various information, a data program retransmission device, an independent broadcasting device, and a telephone data interface device. , in an optical wavelength multiplexing two-way CATV telephone data information communication system using an optical fiber cable as a signal transmission/reception path between each of the devices and each subscriber terminal, the transmitting side connects each of the devices to transmit a signal to the optical fiber. A wavelength converter converts each information source into light of a different wavelength, and an optical coaxial multiplex transmission device transmits the wavelength-converted optical signal to the optical fiber, and the receiving side optically converts the multiplexed optical signal. It has a spectroscopic device that performs spectroscopy and restores each source information on the transmitting side.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. The information providing device 1, television program retransmission device 2, independent broadcasting device 3, and telephone data interface device 4 of the information center 20 are connected to a time division multiplexing device 5 at the next stage. The signals converted and multiplexed into digital signals here are further transmitted to the next stage optical signal conversion device 6, and the digital signals are converted into optical signals having different wavelengths for each information source. The converted optical signal is multiplexed by the optical wavelength division multiplexer 7, input to the optical fiber 40, and sent to the subscriber 30. On the subscriber 30 side, the optical multiplexed signal received via the optical fiber 40 is received and split by the spectrometer 10, and the telephone data terminal 11 receives an optical signal of a required specific wavelength. On the other hand, the digital signal from the telephone data terminal 11 is converted into an optical signal of a specific wavelength assigned to the subscriber by the optical signal converter 9, multiplexed by the optical wavelength multiplexer 12, and transmitted to the information center 20 through the optical fiber 40. Ru. The optical signal received at the information center 20 is demultiplexed by the spectrometer 8, further converted into an electrical digital signal by the telephone data interface device 4, and connected to the upper public line network.

Next, the operation will be explained in detail. In FIG. 1, the signal flow from the information center 20 to the subscriber 30 is downward, and the signal flow from the subscriber to the information center is upward.

First, the flow of signals in the downstream direction will be explained with reference to FIGS. 1 and 2. The information providing device 1, the television program retransmission device 2, the independent broadcasting device 3, and the telephone data interface device 4 are connected to a time division multiplexing device 5, which converts each piece of information into a digital signal and time division multiplexes it. .

For example, digital signals having a transmission rate of about 8 Mbps are further converted into different wavelengths by the next-stage optical signal converter 6 as shown in FIG. For example, different wavelengths λ1, λ2, λ3, . Converted λ1,
The lights of λ2, λ3... are optically focused by the optical wavelength multiplexer 7 and input into the optical fiber 40, and the lights of λ1, λ2
, λ3 . . . transmits information at 8 Mbps to the subscriber 30. On the subscriber 30 side, the multiplexed light is separated by a spectrometer 10, only the necessary wavelength is selected from λ1, λ2, λ3, . . . and a single wavelength digital signal is output to the telephone data terminal 11.

Next, the flow of signals in the upstream direction will be explained with reference to FIGS. 1 and 2. The optical signal converter 9 converts the digital signal from the telephone data terminal 11 into a specific wavelength λa assigned to each subscriber, as shown in FIG.
Convert to λb, λc... The wavelengths λa, λb, λc .
transmitted to. The signal received at the information center 20 side is demultiplexed by the spectrometer 8, converted into an electrical digital signal by the telephone data interface device 4, and connected to the upper public line network.

[0013] As shown in Figure 3, the band on the cable is 10MHz to 450MHz, and the upstream and downstream signals are separated at 60MHz, and one TV channel is allocated for telephone calls, which is a conventional channel with a bandwidth of 6MHz. The configuration corresponds to 90 audio channels at 80 Mbps, but in the channel configuration example of the present invention shown in Figure 2, the bandwidth on the cable is 108 times wider than that of the conventional example.
Information transmission channels will increase dramatically.

[0014]

Effects of the Invention As explained above, the present invention provides two-way C
In ATV data communication systems, optical fibers are used for signal transmission paths with subscribers, and by converting each information source into light of a different wavelength and optically multiplexing it, the channel bandwidth on the cable increases dramatically, increasing the number of transmission channels. This makes it possible to transmit large amounts of data.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a diagram showing an example of a channel configuration of the present invention.

FIG. 3 is a diagram showing an overview of the channel configuration of a conventional CATV network.

[Explanation of symbols]

1 Information providing device 2 Television program retransmission device 3 Independent broadcasting device 4 Telephone data interface device 5 Time division multiplexer 6, 9 Optical signal converter 7, 12 Optical wavelength multiplexer 8, 10 Spectrometer 11 Telephone data terminal 20 Information center 30 Subscriber 40 Optical fiber transmission line

Claims (1)

[Claims] [Claim 1] An information providing device that provides various information, a data program retransmission device, an independent broadcasting device, and a telephone data interface device, and an optical fiber cable is used as a signal transmission/reception path between each of the devices and each subscriber terminal. In an optical wavelength multiplexing two-way CATV telephone data information communication system, the transmission side uses a wavelength conversion device that converts light of a different wavelength for each information source of each device, and a wavelength conversion device to transmit a signal to the optical fiber. The receiver comprises an optical coaxial multiplex transmission device that transmits the multiplexed optical signal to the optical fiber, and the receiving side has a spectroscopic device that optically separates the multiplexed optical signal and restores it to each source information on the transmitting side. Optical wavelength multiplexing bidirectional CATV telephone data information communication system.