KR100633462B1 - System and method for passive optical communication, optical network unit - Google Patents

Abstract

The present invention relates to a passive optical network structure for the construction of a communication network between optical subscriber access devices to establish a local communication network between optical subscriber access devices on a passive optical communication network using an optical fiber diffraction grating or a WDM combiner. An optical fiber diffraction grating having a function of reflecting optical signals in a specific wavelength band or a WDM combiner having a function of separating and combining optical signals in a specific wavelength band is provided between the optical transceiver on the telephone station side and the optical forming coupler, respectively. A separate transmission / reception card for local communication is provided in the optical subscriber access device of the present invention to realize local communication between a plurality of optical subscriber access devices connected to the passive optical communication network system. Therefore, the present invention is to establish a local communication network between optical subscriber access devices using a passive optical communication network system, without having to establish a separate private dedicated network for local communication between optical subscriber access devices for communication between optical subscriber access devices. It is possible to drastically reduce the cost of constructing a local network and to greatly increase the efficiency of using a passive optical network.

Description

Passive Optical Communication System, Optical Communication Method and Optical Subscriber Accessory {SYSTEM AND METHOD FOR PASSIVE OPTICAL COMMUNICATION, OPTICAL NETWORK UNIT}

1 is a block diagram of a passive optical communication network system employing a passive optical communication network structure for configuring a network between optical subscriber access devices according to an embodiment of the present invention;

2 is a block diagram showing a transmission and reception card for telecommunication and a local communication transmission and reception card inserted into each optical subscriber access device according to the present invention;

3 is a block diagram of a passive optical communication network system employing a passive optical communication network structure for configuring a network between optical subscriber access devices according to another embodiment of the present invention;

4 is a block diagram of a typical conventional passive optical network system.

<Description of the code | symbol about the principal part of drawing>

102, 302: optical transceiver 104, 304: single mode optical fiber

106: optical fiber diffraction grating 108, 310: photoforming combiner

110/1-110 / n: Optical subscriber access unit (ONU)

210: Tx / Rx card 212, 222: wavelength division multiplexer

214, 224: transmitter 216, 226: receiver

220: transceiver card for local communication 306: WDM combiner

308: Advertiser

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passive optical network for performing optical communication using optical fibers, and more particularly, to optical network access units (Optical Network Units) scattered in a subscriber's house while maintaining the characteristics of a passive optical network. The present invention relates to a passive optical network structure and a local communication method for constructing a communication network between optical subscriber access devices suitable for realizing a local communication network configuration.

Recently, due to the rapid development of optical communication technology, the subscriber section from the telephone company to the subscriber's home is constructed with FTTH (Fiber To The Home) network, and optical fiber is installed at each entrance of each home or building. There is a need for an optical transceiver located, an optical combiner installed on an optical communication line (i.e., an optical fiber), and an optical subscriber connection device located in a subscriber's home. Here, the passive optical communication network system uses a point-to-multipoint broadcasting method from a transceiver at a point down to a receiver at several points using a splitter, and uplinks each optical subscriber access device ( ONU) refers to a system that sequentially transmits signals (ie, time division multiplexed transmission) to a transceiver at a point.

4 is a block diagram of a typical conventional passive optical network system, which includes an optical transceiver 402 and a photoforming combiner 408 and is connected to multiple optical subscriber access devices 410/1-410 / n. .

Referring to FIG. 4, the optical transceiver 402 is located at the telephone station, not shown, and provides optical signals (time division multiplexing, space division multiplexing, or wavelength division multiplexing) to be transmitted to arbitrary optical subscriber access units (ONUs). The downlink signal) through the subscriber line 404 of single-mode fiber, and the optical signal (time division multiplexing, space division) transmitted from each optical subscriber access device (ONU) located in the subscriber's house through the subscriber line 404 Multiplexed or wavelength division multiplexed uplink signal).

Also, the optical shaping coupler 408 distributes the optical signal (downward signal) transmitted from the optical transceiver 402 and received through the subscriber line 404 to connect each of the plurality of optical subscriber access devices 410/1 connected thereto. 410 / n), time division multiplexing (or spatial division multiplexing, wavelength division multiplexing) the optical signals transmitted from each of the plurality of optical subscriber access devices 410/1-410 / n, and the subscriber line 404 The time division multiplexed optical signal (uplink signal) is transmitted to the optical transceiver 402 through.

Next, each optical subscriber access device 410/1-410 / n is located in the subscriber's home, and is provided with a transceiving card such as a LAN card of a personal computer, for example, from the optical shaping combiner 408. Detects the transmitted optical signal (downward signal), and oscillates an upward signal obtained by converting the digitalized electrical signal into an optical signal and transmits it to the photoforming coupler 408.

At this time, the downlink signal and the uplink signal used in the passive optical communication network system as described above are different in the wavelength band. For example, a signal of 1300 nm wavelength band is used as a downlink signal and a signal of 1550 nm wavelength band is used as an uplink signal. Therefore, each of the optical subscriber access devices (ONU) located in the subscriber's home is composed of a photodiode and a laser diode is provided with a transmission and reception card for detecting a downlink signal and oscillating an uplink signal.

Therefore, each subscriber in the home can be provided with various types of high-speed communication services through a passive optical network system using a single mode optical fiber as described above.

On the other hand, as mentioned above, as the bandwidth of a subscriber's communication increases, many subscribers who rent a few floors in a large building or own buildings scattered in close proximity within the same area, Separately, it is desired to establish a communication network (local communication network) connecting subscriber access devices to each other by using a private dedicated network such as a high-speed LAN (Local Area Network). In recent years, the construction of such a private dedicated network is becoming common.

However, as described above, in the state where the passive optical communication network system using the optical fiber is established, separately installing a network for local communication between optical subscriber access devices can be considered very inefficient from an economic point of view.

Therefore, in view of the foregoing, if it is possible to establish a local communication network between subscriber access devices using the passive optical communication network system, it is possible to reduce the cost of constructing a separate network as well as increase the efficiency of using the passive optical communication network. You will be able to maximize it.

Accordingly, the present invention has been made in view of the above-mentioned point, and the present invention provides a passive network for the construction of a communication network between optical subscriber access devices capable of establishing a local communication network between optical subscriber access devices on a passive optical communication network using an optical fiber diffraction grating or a WDM combiner. The purpose is to provide an optical network structure.

Another object of the present invention is to provide a local communication method between optical subscriber access devices capable of realizing local communication between optical subscriber access devices on a passive optical communication network using an optical fiber diffraction grating.

According to one aspect of the present invention, there is provided a plurality of downlink signals of an arbitrary wavelength band provided from an optical transceiver at a telephone station through an optical fiber, and the plurality of optical subscriber access devices are connected to each other. In the passive optical network structure for transmitting the uplink signal obtained by multiplexing the transmission light provided from each optical subscriber access device to the optical transceiver through the optical fiber, the passive optical network structure, the downlink signal and the uplink signal is passed through And an optical fiber diffraction grating having a wavelength band different from that of the downlink signal and the uplink signal, and reflecting only an optical signal for local communication of a specific wavelength band provided from an optical subscriber access device and transmitting the optical signal to a distributor for distributing optical signals. Each of the optical subscriber access devices generates the optical signal for local communication. And a transmission / reception card for local communication, which transmits to the optical fiber diffraction grating and detects when an optical signal for local communication is received through the splitter.

The present invention according to another aspect of the consistency point to achieve the above object, through the optical fiber distributes the downlink signal of any wavelength band provided from the optical transceiver of the telephone station side to a plurality of optical subscriber access devices connected through the optical forming coupler And a passive optical network structure for transmitting an uplink signal obtained by multiplexing transmission light provided from each of the plurality of optical subscriber access devices to the optical transceiver through the optical fiber, wherein the passive optical network structure includes the downlink signal and the downlink signal; Passes an uplink signal, and separates only an optical signal for local communication of a specific wavelength band provided from an optical subscriber access device and has a wavelength band different from that of the downlink signal and an uplink signal. Further comprising a WDM coupler for transferring to a molded coupler, wherein the photoformed coupler is 2 × N Each of the optical subscriber access devices, the optical subscriber connection device for generating a local signal for transmission to the WDM combiner, and detects when the optical signal for local communication is received through the 2 × N optical combiner It provides a passive optical network structure for the communication network configuration between the optical subscriber access device characterized in that it comprises a transmission and reception card.

According to another aspect to achieve the above object, the present invention is to distribute the downlink signal of any wavelength band provided from the optical transceiver on the telephone station side to the plurality of connected optical subscriber access devices through the optical fiber, A local communication method in a passive optical communication network structure in which an uplink signal obtained by multiplexing transmission light provided from a connection device is transmitted to the optical transceiver through the optical fiber, wherein the optical signal is used for local communication between the optical subscriber access devices. Has a wavelength band different from that of the downlink signal and the uplink signal, and reflects or isolates only the local communication optical signal outputted from a specific optical subscriber access device and distributes the same to any optical subscriber access device for transmission. It provides a local communication method in a passive optical network structure.

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a key technical aspect of the present invention is to provide a passive optical network system using an optical fiber diffraction grating having a function of reflecting optical signals of a specific wavelength band or a WDM combiner having a function of separating and combining optical signals of a specific wavelength band. To establish a local communication network between a plurality of connected optical subscriber access devices, for this purpose, each optical subscriber access device is provided with a separate transmission and reception card for local communication between the optical subscriber access devices. Therefore, it is possible to easily achieve the object of the present invention by realizing local communication between a plurality of optical subscriber access devices connected by using an optical fiber diffraction grating or a WDM combiner and a transmission / reception card for local communication.

Example 1

1 is a block diagram of a passive optical communication network system employing a passive optical communication network structure for configuring a network between optical subscriber access devices according to an embodiment of the present invention.

Referring to FIG. 1, the passive optical network system according to the present embodiment has the largest optical fiber diffraction grating 106 between the optical transceiver 102 and the 1 × N photoforming combiner 108 located at the telephone station side. It has technical features. Therefore, since the process of processing the uplink signal and the downlink signal in the passive optical communication network system is the same as the conventional method described above, the detailed description thereof will be omitted, and in the following, the area between the optical subscriber access devices through the local communication network built in the passive optical communication network system Only the process of performing communication is demonstrated.

Here, the optical fiber diffraction grating 106 passes the wavelength band of the uplink signal (for example, 1550 nm) and the wavelength band of the downlink signal (for example, 1300 nm) as it is, and the area between the optical subscriber access unit (ONU). The wavelength band of the local communication signal (for example, 1554 nm, 1553 nm, etc.) for communication has a property of reflecting.

That is, in the passive optical communication network structure according to the present embodiment, the optical transceiver 102 ↔ single mode optical fiber 104 ↔ 1 × N optical forming coupler 108 ↔ a plurality of optical subscriber access devices (ONU) through a path leading to a long distance Establish an optical communication network for communication, and use optical subscriber access unit (ONU) ↔ 1 × N optical forming coupler (108) ↔ optical fiber grating (106) ↔ 1 × N optical forming combiner (108) ↔ optical subscriber access unit (ONU) The local path is formed through the following path.

Therefore, in order to configure the local communication network as described above, each optical subscriber access device (ONU), as shown in FIG. 2 as an example, the telecommunication transmission and reception card 210 and the local communication transmission and reception card 220 for telecommunications Each is provided. Here, the telecommunications transmission / reception card 210 includes a first wavelength division multiplexer 212, a first transmitter 214, and a first receiver 216, and the local communication transmission / reception card 220 includes a second wavelength division. A multiplexer 222, a second transmitter 224, and a second receiver 226. In this case, the first and second wavelength division multiplexers 212 and 222 when the downlink signal provided from the photoforming combiner 108 of FIG. 1 to each optical subscriber access device (ONU) is a time division multiplexing signal or a spatial division multiplexing signal. ) Is replaced by a time division multiplexer or a space division multiplexer.

Referring to FIG. 2, the transmitting / receiving card 210 for telecommunication processes the uplink signal and the downlink signal generated during the long-distance optical communication (that is, the transmission light generation and the reception light detection), and the first wavelength division multiplexer 212. Is a number that separates the transmitted and received light, i.e., transmits the transmitted light (e.g., 1550 nm) generated at the first transmitter 214 to the photoforming coupler 108 and provides the number provided from the photoforming coupler 108. Divine light (eg, 1300 nm) is delivered to the first receiver 216. In addition, the first transmitter 214 is composed of, for example, a laser diode and generates a first wavelength division multiplexer by generating an optical signal having an arbitrary wavelength band (eg, 1550 nm) corresponding to an electrical signal to be transmitted. Transmitted to 212, the first receiver 216 is comprised of, for example, a photodiode and received light of any wavelength band (e.g., 1300 nm) provided from the first wavelength division multiplexer 212. Is detected.

Next, the local communication transmission / reception card 220 processes an optical signal generated during local communication (that is, transmit light generation and reception light detection), and the second wavelength division multiplexer 222 performs a second transmitter 224. ) Transmits the transmitted light (e.g., 1554 nm) to the 1xN photoforming coupler 108, and receives the light (e.g., 1554 nm) provided from the 1xN photoforming coupler 108. Is transmitted to the second receiver 226. In addition, the second transmitter 224 is composed of, for example, a laser diode and generates a second wavelength division multiplexer by generating an optical signal having an arbitrary wavelength band (for example, 1554 nm) corresponding to an electrical signal to be transmitted. 222, the second receiver 226 consists of, for example, a photodiode and receives light of any wavelength band (eg, 1554 nm) provided from the second wavelength division multiplexer 222. Is detected.

Therefore, in the passive optical communication network structure according to the present embodiment having the above-described configuration, when the local communication optical signal is output from any optical subscriber access device (for example, 110/1), the local communication optical signal is output. The 1xN photoforming coupler 108 is transmitted to the optical fiber diffraction grating 106, and thus the optical signal for local communication is reflected by the optical fiber diffraction grating 106 and distributed through the 1xN photoforming coupler 108. This allows delivery to multiple other optical subscriber access devices 110/2-110 / n, i.e., high speed independent local transmission between optical subscriber access devices.

In this case, there may be a case where an arbitrary optical subscriber access device (ONU) wants to transmit arbitrary data only to a specific optical subscriber access device selected by the user, not all optical subscriber access devices. Local communication with a specific optical subscriber access device can be realized by inserting and transmitting identifier information (ID) of the optical subscriber access device for transmission in the header.

Meanwhile, in the present embodiment, the optical fiber diffraction grating and the 1 × N photoforming coupler are illustrated and described as an example, but the present invention is not necessarily limited thereto. 1 × N photoforming couplers can be implemented.

Therefore, according to the passive optical network structure according to the present embodiment, an optical fiber diffraction grating having a function of reflecting an optical signal of a specific wavelength band is provided between the optical transceiver on the telephone station side and the 1 × N optical forming coupler, and each optical By separately providing a transmission / reception card for local communication in the subscriber access device, it is possible to easily implement a local communication network between a plurality of optical subscriber access devices connected to the passive optical communication network system by simply changing the structure of the passive optical communication network.

Example 2

3 is a block diagram of a passive optical communication network system employing a passive optical communication network structure for configuring a network between optical subscriber access devices according to another embodiment of the present invention.

Referring to FIG. 3, in the passive optical network structure according to the present embodiment, unlike the optical fiber diffraction grating for establishing a local communication network between the optical subscriber access devices in Embodiment 1, the WDM combiner is used for constructing the local communication network. The difference is that a 2 × N photoforming coupler is used instead of a 1 × N photoforming coupler as the photoforming coupler. Here, the WDM combiner employed in the passive optical network structure of this embodiment has higher isolation characteristics than the optical fiber diffraction grating.

In addition, in the passive optical network structure according to the present embodiment, an optical isolator (eg, 1310 nm (1.3 μm)) is transmitted on an area (for example, 1310 nm (1.3 μm)) where local communication optical signals used in the local communication network are transmitted. 308 may be provided. Here, the optical isolator 308 is for preventing the optical signals inserted in opposite directions from affecting each other, and when the signals of the 1310 nm (1.3 µm) wavelength band are used as the local network optical signals, 1310 nm (1.3 µm) The optical isolator of the area is used.

That is, the passive optical communication network structure according to the present embodiment employs the WDM coupler 306 instead of the optical fiber diffraction grating 106 of FIG. 1, and 2 × N instead of the 1 × N photoforming coupler 108 of FIG. 1. The optical fiber coupler 310 is employed and is substantially the same as the passive optical network structure according to Embodiment 1 described above, except that the optical isolator 308 can be selectively used as needed.

Therefore, in order to avoid unnecessary overlapping description for the sake of brevity of the description, only the operation process of the portion different from the passive optical network structure according to the first embodiment (that is, the WDM combiner 306) will be described in detail below.

Referring to Fig. 3, optical signals transmitted from any optical subscriber access device (ONU), that is, optical signals for telecommunication (1550 nm (1.5 mu m): lambda 1) and local communications optical signals 1310 nm (1.3 mu m): lambda 0). Passes through the WDM coupler 306 via a 2 × N photoforming coupler 310, where λ1 and λ0 are each separated into different ports, and λ1 (telecommunication signal) is via a single mode optical fiber 304 Is distributed to the optical transceiver 302 on the telephone station side, and λ 0 (local communication signal) is distributed to each optical subscriber access unit ONU via the 2 × N photoforming combiner 310.

That is, in the passive optical communication network structure according to the present embodiment, the optical subscriber access device (ONU) → 2 × N photoforming coupler 310 → WDM coupler 306 → 2 × N photoforming coupler 310 → optical subscriber access device A local network is formed through a path leading to the (ONU).

In this case, the passive optical communication network structure according to the present embodiment may use the optical isolator 308 in the λ 0 region as needed, and the optical isolator 308 may be configured to affect the optical signals inserted in opposite directions. It is to prevent.

That is, when the optical isolator 308 is used in the λ 0 area as needed, the passive optical network structure according to the present embodiment is the optical subscriber access unit (ONU) → 2 × N photoforming coupler 310 → WDM combiner ( 306) → optical isolator 308 → 2 × N photoforming combiner 310 → optical communication network (ONU) to form a local communication network.

Accordingly, the passive optical network structure according to the present embodiment is a result of the passive optical network structure of the first embodiment described above, that is, a plurality of optical subscriber access devices connected to the passive optical network system through a simple structure change of the passive optical network structure. Local network can be easily implemented.

On the other hand, the passive optical network structure according to the present embodiment, unlike the passive optical network structure of the first embodiment using the optical fiber diffraction grating, compared to the optical fiber diffraction grating, compared to the optical fiber diffraction grating using a WDM combiner having a higher isolation performance than the improved performance Has the advantage of obtaining.

In addition, in the passive optical network structure according to the first embodiment described above, since the optical fiber diffraction grating selects and reflects only one specific wavelength band, when using multiple wavelengths for local communication, a plurality of optical fiber diffraction gratings having different reflection wavelength bands are used. In the passive optical network structure of this embodiment, the WDM combiner separates the 1550 nm and 1300 nm bands, whereas the inconvenience of using or using a wide bandwidth optical fiber diffraction grating is required. Another advantage is that it can be used.

As described above, according to the present invention, an optical fiber diffraction grating having a function of reflecting an optical signal in a specific wavelength band or a WDM combiner for separating and combining an optical signal in a specific wavelength band is provided between the optical transceiver on the telephone station side and the optical forming coupler. By providing a separate transmission / reception card for local communication in each optical subscriber access device, local communication is realized between a plurality of optical subscriber access devices connected to the passive optical communication network system. Therefore, in the present invention, since the local communication network is established between the optical subscriber access devices using the passive optical communication network system without establishing a private dedicated network, the cost required for constructing the local communication network for the communication between the optical subscriber access devices can be greatly reduced. Not only can it greatly improve the utilization efficiency of passive optical networks.

Claims (8)

A downlink signal of any wavelength band provided from the optical transceiver on the telephone station side through an optical fiber, including an optical transceiver and a photoforming combiner, to the plurality of connected optical subscriber access devices, and from each of the plurality of optical subscriber access devices In a passive optical communication system for transmitting an uplink signal obtained by multiplexing the provided transmission light to the optical transceiver through the optical fiber, Passes the downlink signal and the uplink signal, and has a wavelength band different from that of the downlink signal and the uplink signal, and reflects only the optical signal for local communication of a specific wavelength band provided from an optical subscriber access device to distribute the optical signal. Including optical fiber diffraction grating transmitting Passive optical communication system. The method of claim 1, The header of the optical signal for local communication includes identifier information of at least one selected optical subscriber access device for transmission. Passive optical communication system. A downlink signal of any wavelength band provided from the optical transceiver on the telephone station side through an optical fiber to a plurality of optical subscriber access devices connected through the optical shaping coupler, including an optical transceiver and a optical shaping coupler; In a passive optical communication system for transmitting an uplink signal obtained by multiplexing the transmission light provided from the optical subscriber access device to the optical transceiver through the optical fiber, Passes the downlink signal and the uplink signal, and separates only the optical signal for local communication of a specific wavelength band provided from an optical subscriber access device and has a wavelength band different from that of the downlink signal and the uplink signal. A WDM coupler for transmitting a signal to the photoforming coupler Passive optical communication system. 4. The header of the optical signal for local area communication includes identifier information of at least one selected optical subscriber access device for transmission. Passive optical communication system. The method according to claim 3 or 4, And an optical isolator provided on an area of the separated local communication optical signal. Passive optical communication system. The downlink signal of any wavelength band provided from the optical transceiver on the telephone station side is distributed to the plurality of connected optical subscriber access devices through the optical fiber, and the uplink signal obtained by multiplexing the transmission light provided from each of the plurality of optical subscriber access devices is In the passive optical communication method for transmitting to the optical transceiver through the optical fiber, And when the optical signal for local communication having a wavelength band different from that of the downlink signal and the uplink signal is transmitted from the optical subscriber access device, reflecting or separating only the optical signal for local communication and distributing it to the receiving optical subscriber access device. Passive optical communication method. The method of claim 6, The header of the optical signal for local communication includes identifier information of at least one selected optical subscriber access device for transmission. Passive optical communication method. An optical subscriber access device which detects a downlink signal transmitted from a photoforming coupler of an optical communication system, oscillates an uplink signal converted from an electrical signal into an optical signal, and transmits the uplink signal to the photoforming coupler. A local wavelength optical signal of a specific wavelength band provided from an optical subscriber access device having a wavelength band different from that of the downlink signal and the uplink signal, transmitted to the optical communication system, and among the signals transmitted from the optical communication system Local communication transmitting and receiving card for detecting the optical signal for communication Optical subscriber interface.

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