KR20040107943A - Signal delivery over optical access networks based on ethernet - Google Patents

Abstract

PURPOSE: A system for transferring signals in an ethernet-based optical subscriber network is provided to transmit a large capacity broadcasting signal through an ethernet-based optical subscriber network using some wavelength combiners and a power distributor. CONSTITUTION: In case that a CO(Central Office)(A) transfers an optical communication signal and an optical broadcasting signal to a subscriber through an optical fiber, the optical communication signal is transmitted to an Ethernet switch(12) and the optical broadcasting signal is transmitted to a wavelength combiner(14). The wavelength combiner(14) combines the optical communication signal and the optical broadcasting signal and outputs the wavelength-combined signal to the optical fiber. As a wavelength combiner(22) in a remote node unit(B) executes wavelength separation for the wavelength-combined signal transmitted through the optical fiber, the optical communication signal is outputted to an Ethernet switch(24) and the optical broadcasting signal is outputted to a power distributor(26).

Description

Signal delivery device in Ethernet based optical subscriber network {Signal delivery over optical access networks based on ethernet}

The present invention relates to an optical Ethernet subscriber network device, and more particularly, to a signal transmission device capable of simultaneously transmitting a broadcasting video signal and a communication signal through an optical Ethernet network by adding a broadcasting channel to the optical Ethernet network. .

Optical subscriber network refers to a communication network and is widely used for high-speed Internet access, and its use is expected to be further expanded in the future.

In particular, since the Internet is based on Ethernet, the optical subscriber network using the Ethernet switch has an advantage in the market due to compatibility and excellent economic efficiency.

Recently, due to the convergence of broadcasting and communication, there is a need to transmit not only communication data but also multi-channel video or TV signals in optical subscriber networks, which are broadband subscriber networks.

However, since the Ethernet switch used in the optical Ethernet network is a photoelectric conversion device, a broadband multi-channel video or TV signal cannot be transmitted, and thus a broadcasting network must be separately constructed from the data communication network. Typical broadcasting networks include CATV or hybrid fiber coaxial (HFC) networks.

The big difference between the broadcasting network and the data communication network is divided into two-way transmission 1: 1 or one-way transmission 1: N. The data communication network is inherently different from the broadcasting network in which a broadcasting station transmits a large amount of the same signal to each subscriber because it is intended to connect specific persons in both directions.

However, the Ethernet switch is a representative communication network device, not only easy to implement a broadcast network but also cannot transmit a large amount of video signals.

Accordingly, an object of the present invention for solving the above problems is to enable the simultaneous transmission of a large amount of video signals for broadcasting as well as communication signals (Ethernet signals) using an Ethernet-based optical subscriber network.

1 is a block diagram showing the configuration of a signal transmission device according to the present invention.

2 shows a spectrum of a signal according to the invention.

Signal transmission apparatus of the present invention for achieving the above object is an Ethernet-based optical subscriber network, telephone station apparatus for combining and outputting the Ethernet signal and the broadcast signal applied to different paths to be transmitted to the subscriber terminal; And dividing an output signal of the telephone station apparatus into the Ethernet signal and the broadcast signal, the separated Ethernet signal is switched to the subscriber station, and the broadcast signal is distributed power, and then the switched Ethernet signal and the power distribution. And a remote node device for transmitting the broadcast signal to the subscriber station.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a configuration diagram showing the overall configuration of a signal transmission device according to the present invention.

First, in telephone station A, Ethernet switch (ES) 12 is a network-side switching hub used in Ethernet-based optical subscriber network (hereinafter referred to as optical subscriber network). Office) switches and outputs a communication signal (Ethernet signal) to be transmitted to each subscriber. To this end, the Ethernet switch 12 converts the received communication optical signal into an electrical signal, and then switches and multiplexes / demultiplexes the converted optical signal and outputs the converted optical signal. In this case, the Ethernet switch 12 used may be replaced by a router as necessary. Since the functions of these Ethernet switches 12 are the same as those of the conventional ones, detailed description thereof will be omitted.

The wavelength combiner 14 combines optical signals having different wavelengths and outputs them to the optical fiber 30. The broadcast video signal (multi-channel broadcast and video signal, hereinafter called broadcast optical signal) and the communication optical signal are transmitted through the optical fiber using different wavelengths as shown in FIG. Accordingly, the wavelength combiner 14 combines the communication optical signal (solid line in FIG. 1) output from the Ethernet switch 12 with the optical signal for broadcasting (dotted line in FIG. 1) having a different wavelength and outputs the optical signal to the optical fiber 30. .

Furthermore, Ethernet switch 12 currently uses different optical fibers for transmission and reception. If different wavelengths (1300 nm and 1480 nm) are used for transmission and reception of communication optical signals, the Ethernet switches 12 may have low values as shown in FIG. Two transmission / reception optical signals having power and two broadcasting optical signals having high power may be transmitted through one optical fiber 30. In this case, although two wavelengths are used as broadcast signals in FIG. 2, one of the two wavelengths may be used.

In the remote node device B for transmitting the optical signal from the telephone station A to each subscriber station (not shown), the wavelength combiner 22 is different from the preset signal in the optical signal received through the optical fiber 30. The wavelength signal, that is, the communication optical signal and the broadcast optical signal are separated and output.

The Ethernet switch 24 converts the optical signal for communication separated in the wavelength coupler 22 into an electrical signal, and then switches and multiplexes and demultiplexes the converted optical signal, and then converts the optical signal into an optical signal and outputs it to each subscriber line.

The power divider 26 divides the power of the optical signal for broadcasting separated by the wavelength combiner 22 by the desired number and outputs the power to each subscriber line connected to the output port of the Ethernet switch 24.

The wavelength combiner 28 is installed at the output port of the Ethernet switch 24 and combines and outputs the optical signal for communication output from the Ethernet switch 24 and the optical signal for broadcasting output from the power divider 26.

The operation of the signal transmission device having the above-described configuration will be briefly described as follows.

When a telephone station (or CO) A wants to transmit a communication optical signal and a broadcast optical signal to a corresponding subscriber through one optical fiber 30, the communication optical signal is transmitted to the Ethernet switch 12 as in the prior art and the optical signal for broadcasting Transmits to the wavelength combiner 14.

In general, the Ethernet switch 12 can accommodate dozens of ports depending on the type, the trunk speed is mainly used 100Mb / s, 1Gb / s, and mainly provides 100Mb / s bandwidth to each subscriber. The Ethernet switch 12 converts the optical signal into an electrical signal, and then converts the optical signal into an optical signal, converts the optical signal into an optical signal, and then converts the optical signal into an optical signal. However, in the case of TV signals, the optical signal for broadcasting uses a band of 6 MHz per channel, and the digital signal uses 2 MHz to several tens of MHz. Therefore, in order to transmit 100 channels of analog TV, a bandwidth of about 600 MHz is required, and in case of transmitting 100 channels of digital TV, signals of 200 GHz to several GHz must be transmitted. As such, the Ethernet switch 12 cannot provide a bandwidth capable of delivering a large amount of broadcast optical signal to each subscriber, and the broadcast optical signal does not go through the optical-to-optical conversion in the Ethernet switch 12. As a result, the Ethernet switch 12 does not simultaneously transmit the optical signal for broadcasting and the optical signal for communication.

Thus, as shown in FIG. 1, the broadcast signal is transmitted to the wavelength combiner 14 through a separate optical fiber (dotted line).

The wavelength combiner 14 combines the communication optical signal output through the Ethernet switch 12 and the broadcasting optical signal directly applied to the optical fiber 30.

The optical signal for communication and the optical signal for broadcasting transmitted through the optical fiber 30 are wavelength-coupled and the wavelength is separated by the wavelength combiner 22 of the remote node device B. The communication signal is output to the Ethernet switch 24 and the optical signal for broadcasting is Are output to the power dividers 26, respectively.

The communication signal applied to the Ethernet switch 24 is converted into an electrical signal, switched to each subscriber line, multiplexed / demultiplexed, and then converted into an optical signal and output again, and the broadcast optical signal applied to the power distributor 26 is transmitted. The power is divided by the number of subscribers to be output and output to the wavelength combiner 28. Since the broadcast optical signal is transmitted to all subscribers, the same signal is transmitted at a large power in the transmission stage, and power is distributed to each subscriber terminal (ONT: Optical Network Terminal) (not shown).

The wavelength combiner 28 combines the communication optical signal output from the Ethernet switch 24 and the broadcast optical signal output from the power splitter 26 and transmits the optical signal for transmission to each subscriber station (not shown). Each subscriber station (not shown) transmits a communication signal to a PC or other Ethernet device, and a broadcast signal to a TV or set-top box.

In the above-described embodiment, the wavelength combiner 14, 22, 28 and the power divider 24 can be implemented using optical fibers or integrated optical waveguide elements. In addition, an optical amplifier may be added to amplify the optical signal to compensate for the loss of the broadcast signal by the power divider 24.

As described above, the signal transmission device of the present invention can transmit a large-capacity broadcast signal using an Ethernet-based optical subscriber network using broadcast signals using several wavelength combiners and power dividers.

Claims (5)

In the Ethernet-based optical subscriber network, A telephone station apparatus for combining and outputting an Ethernet signal and a broadcast signal applied through different paths to be transmitted to a subscriber station; And The output signal of the telephone station apparatus is separated into the Ethernet signal and the broadcasting signal, the separated Ethernet signal is switched to the subscriber station, and the broadcasting signal is divided into power, and then the switched Ethernet signal and the power distribution are divided. And a remote node device which combines a broadcast signal and transmits the signal to the subscriber station. The apparatus of claim 1, wherein the telephone station apparatus A first Ethernet switch for switching and outputting the Ethernet signal; And And a first wavelength combiner for wavelength-combining an Ethernet signal output from the Ethernet switch and a broadcast signal applied to a different optical path from the Ethernet signal and outputting the optical signal to an optical fiber. The apparatus of claim 2, wherein the remote node device is A second wavelength combiner for separating the optical signal output from the first wavelength combiner into the Ethernet signal and the broadcast signal; A power divider for distributing power of the broadcasting signal wavelength-divided by the second wavelength combiner by an arbitrary number; A second Ethernet switch for switching and outputting the Ethernet signal separated by the second wavelength combiner; And And a third wavelength combiner for wavelength combining the output signal of the power splitter and the output signal of the second Ethernet switch and outputting the wavelength to the subscriber station. The method of claim 2 or 3, And an optical amplifier for amplifying the output signal of the power divider to compensate for the branch loss of the broadcast signal by the power divider. The method of claim 2 or 3, And the wavelength combiner and the power divider are integrated optical waveguide elements.