WO2012102557A2

WO2012102557A2 - Optical network system between optical line terminals in a time division passive optical network

Info

Publication number: WO2012102557A2
Application number: PCT/KR2012/000613
Authority: WO
Inventors: 조원국; 양광진; 조주철
Original assignee: (주)옵토위즈
Priority date: 2011-01-26
Filing date: 2012-01-26
Publication date: 2012-08-02
Also published as: WO2012102557A3

Abstract

The present invention relates to an optical network system between optical line terminals in a time division passive optical network. The present invention comprises forming an optical network between optical line terminals (OLT), one of which exists in each optical network of multiple members comprised of a time division passive optical network, based on wavelength division multiplexing. According to the invention, more economic and efficient optical network conditions are provided between optical line terminals in a time division passive optical network.

Description

Specification

Name of the Invention: Optical Network System Between Fiber Optic Termination Devices in Time Division Passive Optical Networks

Field of technology

[1] The present invention provides an optical line termination device in a time division passive optical network.

Termination, hereinafter referred to as OLT), and more specifically, a communication channel between OLTs existing in one of a plurality of optical subscriber networks constituting a time division passive optical communication network system.

The present invention relates to an optical network system that provides a more economical and efficient optical network environment between OLTs by being formed based on Wavelength Division Multiplexing.

[2]

Background

[3] With the rapid increase in internet traffic and the convergence of broadcasting and telecommunications services,

The speed of the communication network is actively being made. Among these technologies, Passive Optical Network (PON) technology not only can provide high bandwidth to subscribers, but also because the OSP (OutSide Plant) consists only of passive elements. The introduction is spreading due to the advantage of greatly reducing the cost of operation.

[4] PON offers fiber-based high-speed services to businesses, SOHO and homes.

One of the optical subscriber construction methods to provide, in simple terms,

A splitter is used to allow a single OLT to connect a subscriber network (optical network unit).

[5] ΡΟΝ systems typically include Giga-bit Passive Optical Network (GPON)

There are two specifications of the EPON (IEEE 802.3 Ethernet Passive Optical Network). GPON was standardized by the International Telecommunication Union (ITU), and EPON was conducted by the IEEE.

1 is a time division passive optical network according to the prior art (Time Division)

FIG. 1 illustrates a configuration of one optical subscriber network in a multiplexing-PON (hereinafter, referred to as a 'TDM-PON').

[7] As shown in FIG. 1, the TDM-PON according to the prior art has a light path on the side of a national company.

Optical signal distribution between the terminating device (TDM-PON OLTX10), the optical fiber subscriber device (TDM-PON ONT) 20 on each subscriber side, the optical fiber terminating device 10 and the optical fiber subscriber device 20 ( Splitter 30 for optical signal power branching, optical signal power coupling).

[8] The fiber optic termination device (10) includes TI) M-PON MAC & PHY modules (11) and TDM-PON An optical transceiver (TDM-PON TR _BMR ) 12 is made up of TDM-PON ONT 20, which consists of a TDM-PON MAC & PHY module 21 and a TDM-PON optical transceiver (TDM-PON TR _BMT ) 22.

[9] The TDM-PON is a structure in which a plurality of subscriber-side optical line subscriber devices 20 share an optical fiber with an optical fiber termination device 10 on the domestic side by using a time division technique, and B-PON standardized in ITU-T. And G-PON, and the E-PON standardized by the IEEE are currently in use.

[10] The signal transmission method in the TDM-PON will be briefly described. In terms of the downward signal, the optical fiber terminator 10 broadcasts the traffic transmitted to each optical fiber subscriber device 20, and remotely. ΙχΝ splitters 30 are provided to split the optical power, and distribute the downlink signals received from the optical line terminating device 10 to N subscriber lines, and receive the down signal received from the optical line subscriber device 20 to itself. Only the frames that are timed to them are selectively delivered to subscribers.

[11] Looking at the point of view of the upstream signal, the optical line subscriber device 20

The time slots assigned to them, with their own dedicated time slots pre-assigned from the fiber terminator 10 through ranging and dynamic bandwidth allocation (DBA) processes, etc. TDM-PON Optical Transceiver (TDM-PON)

[Shut down] is completely turned off. To support this, the TDM-PON optical transceiver 22 of the optical subscriber unit 20 is equipped with a burst mode transmission (TR _BMT ) transceiver with burst. -mode transmitter).

[12] The upward signal from each optical line subscriber device 20

The TDM-PON optical transmitter 12 of the optical fiber terminator 10 has a burst mode receiving function in order to support the uplink signal having the burst mode characteristics. It is implemented as a _fully equipped optical transceiver (TR _BMi ) with a burst-mode receiver.

On the other hand, a fixed wavelength light source of 1480 nm to 1500 nm band is normally used for the optical fiber terminating device 10, and a fixed wavelength light source of 1260 nm to 1360 nm band is used for the optical line subscriber device 20.

[14] The standardization mechanism for the next-generation TDM-PON discusses the possibility of changing the uplink wavelength and the downlink wavelength, and measures for increasing the bandwidth by distributing the downlink signal to multiple wavelength optical transmitters.

[15] In time-division passive optical network, optical network configuration is divided into two.

An optical communication network configuration between optical line termination devices (OLTs) and a second optical communication network configuration between an optical fiber termination device (OLT) and a plurality of optical fiber subscriber equipment (ONU) in the optical subscriber network.

[16] Looking at the optical network configuration between optical fiber terminators (OLTs), each communication channel Point-to-Point type structure is connected, and the optical network configuration between one optical line terminator (OLT) and multiple optical subscriber units (ONU) in the optical subscriber network is point-to-point. to-Multi-Point) structure.

[17] Therefore, the number of optical cables should be

By doing so, there is a problem of inefficient and high cost in forming an optical network.

Detailed description of the invention

Technical challenges

[18] The present invention provides a wavelength division multiplexing scheme in which optical fiber termination devices (OLTs), one for each optical subscriber network constituting a time division passive optical communication network system, form a communication channel with each other. It is configured to be formed on the basis of. The aim is to provide an optical network system between optical fiber end devices that provides a more economical and efficient optical network environment between optical fiber ^ end devices (OLTs). _.

Challenge solution

In order to achieve the above object, an optical network system between optical fiber termination devices in a time division passive optical communication network according to the present invention exists in a first optical subscriber network in a time division passive optical communication network having a plurality of optical subscriber networks. First ray termination device; A second optical fiber terminal device present in the second optical subscriber network; Receives transmission signals having a transmission wavelength preset for each communication channel from a plurality of communication channels of the first optical fiber terminal device, multiplies the received plurality of transmission signals, and transmits them on one optical cable; A first multiplexing and demultiplexing device for demultiplexing a reception signal received through the one optical cable and transmitting a signal corresponding to a reception wavelength of each communication channel to each communication channel of the first optical fiber terminal; And receiving the multiplexed signal transmitted by the first multiplexing / demultiplexing device through the one optical cable, and demultiplexing the received signal to each communication channel of the second optical fiber termination device. Transmit a signal corresponding to a reception wavelength, or receive transmission signals having a unique transmission wavelength preset for each communication channel from a plurality of communication channels of the second optical fiber terminal, and split the plurality of transmission signals. And a second multiplexing and demultiplexing device for multiplexing and then transmitting the single optical cable.

[2] According to an embodiment of the present invention, the first optical fiber terminal device and the second optical fiber cable terminal device include a plurality of optical transceivers forming a communication channel, and the optical transceiver includes CWDM (Coarse Wavelength). Division Multiplexing) A bidirectional optical transmitter and receiver that forms a communication channel in which the transmission signal and the reception signal have different wavelengths. According to another embodiment of the present invention, the first optical fiber terminal device and the low] two optical fiber terminal device includes a plurality of optical transceivers forming a communication channel, wherein the optical transmitter, It is a CWDM (Coarse Wavelength Division Multiplexing) communication channel and a bidirectional optical transmitter / receiver that forms a communication channel in which a transmission signal and a reception signal have the same wavelength.

Preferably, the first multiplexing and demultiplexing apparatus and the second multiplexing and demultiplexing apparatus may be configured by using a thin film filter. In addition, the first multiplexing and demultiplexing apparatus and the second multiplexing and demultiplexing apparatus may be configured of an arrayed waveguide grating (AWG).

[23]

Effects of the Invention

According to the present invention, a plurality of communication channels between optical fiber termination devices in a time division passive optical communication network can be connected to each other through a single optical cable. Therefore, the cost of embedding optical cables is reduced compared to forming an optical network one-to-one using optical cables by the number of communication channels. In addition, in terms of optical cable utilization, a plurality of communication channels are provided through one optical cable. Increases efficiency by enabling connectivity.

[25]

Brief description of the drawings

Multiplexing-PON) is a view showing the configuration of one optical subscriber network.

FIG. 2 is a diagram illustrating an optical network system between an optical line termination device (OLT) according to a first embodiment of the present invention.

3 is a diagram illustrating an optical network system between an optical path terminating apparatus (OLT) according to a second embodiment of the present invention.

[29]

Form for the implementation of the invention

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are represented by the same reference numerals as much as possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

[31]

In FIG. 2, first, optical transmitters (first optical receiver, second) in which the first optical fiber terminal 100 and the second optical fiber terminal 200 form a communication channel therebetween.

Optical receiver, .. ninth optical transmitter) CWDM (Coarse Wavelength Division) Multiplexing) is shown with two-way optical transceivers forming a communication channel.

[34] The wavelength of CWDM is about 20nm between 1270nm and 1610nm.

It consists of a total of 18 wavelengths (λ ^., Λ ^) at intervals and the actual wavelength is 1271nm, 1291nm, 131 lnm, 1331nm, 1351nm, 1371nm, 1391nm, 141 lnm, 1431nm, 1451nm, 1471nm, 1491nm, 1511nm, 153 lnm , 1551 nm, 157 lnm, 1591 nm, and 1611 nm.

[35] Thus, as shown in the drawing, the optical fiber terminator (OLT) 100,200 communicates with CWDM.

When a bidirectional optical transceiver having a channel is formed, and the optical transceiver forms a communication channel having a wavelength different from that of a transmission signal and a reception signal, the optical path terminators 100 and 200 have a maximum of 9 Communication channels can be formed.

[36] When the transmission signal (Tx) wavelength set in the communication channel of the first optical fiber terminal 100 is equal to, the reception signal Rx wavelength of the communication channel connected to the second optical fiber terminal 100 is is set to λ. On the contrary, the symmetrical form will naturally be predictable.

The first multiplexing / demultiplexing apparatus 300 receives transmission signals having a predetermined unique transmission wavelength for each communication channel from up to nine communication channels of the first optical fiber terminal 100. The plurality of transmission signals are wavelength-division multiplexed and then transmitted through one optical cable.

[0038] The second multiplexing / demultiplexing apparatus 400 provides a low U through the one optical cable.

Receives the multiplexed signal transmitted from the multiplexing / demultiplexing device 300, demultiplexes the received signal, and transmits the signal corresponding to the reception wavelength of each communication channel to each communication channel of the second optical fiber terminal 400. Send it.

[39] The reverse is also true.

The second multiplexing / demultiplexing apparatus 400 receives transmission signals having a predetermined unique transmission wavelength for each communication channel from up to nine communication channels of the second optical fiber terminal 200. The plurality of transmission signals are wavelength-division multiplexed and then transmitted through one optical cable.

The first multiplexing / demultiplexing device 300 is connected to the low-frequency cable via the optical cable.

Receives the multiplexed signal transmitted from the multiplexing / demultiplexing apparatus 400, demultiplexes the received signal, and transmits a signal corresponding to the reception wavelength of each communication channel to each communication channel of the first optical fiber terminal 100. send.

[42] Preferably, in the present invention, the first multiplexing / demultiplexing apparatus 300 and the second

The multiplexing / demultiplexing apparatus 400 may have a configuration including an arrayed waveguide grating (AWG), thereby minimizing the cost of a light source when forming an optical network.

In addition, in the present invention, the first multiplexing / demultiplexing apparatus 300 and the second multiplexing / demultiplexing

The device 400 is equipped with a thin film filter to perform multiplexing / demultiplexing. It is desirable to have a configuration to perform.

In addition, the optical transceivers are configured to have a transmission speed of 1.25Gbps or 2.5Gbps, and the present invention can be applied to both GPON and EPON, which are time division passive optical communication networks.

[45] On the other hand, in time-division passive optical networks, optical fiber terminators (OLTs) 100,200 and

The optical path subscriber device (ONU) (not shown) communicates with a wavelength of 1490 nm as the downlink signal and 1310 nm as the wavelength of the uplink signal. Therefore, the optical fiber termination device (OLT) 100,200 is configured to have a wavelength converter (not shown), so that the optical network system between the optical fiber termination device (OLT) 100,200 according to the present invention is a conventional time division passive type. It can be configured to be applied to the optical network system as it is.

[46] The wavelength converter (not shown) in the optical fiber terminator (OLT) 100,200 is an optical / electric / optical light.

Change the signal in a manner. The wavelength conversion unit (not shown) converts only the wavelength of the received optical signal and retransmits it, the 2R method of changing and retransmitting the wavelength and signal type at the same time, and the wavelength, signal type and timing at the same time. Configurable in 3R mode to change and retransmit. In particular, it is preferable that the wavelength conversion unit (not shown) be configured in a 2R or 3R scheme which is mainly used.

As described above, the present invention terminates the first optical path in a time division passive optical communication network.

A plurality of communication channels between the device 100 and the second optical fiber termination device 200 enables connection with each other via a single optical cable. Therefore, the cost of laying the optical cable is reduced compared to forming the optical network in a one-to-one manner by using the optical cable by the number of communication channels. In addition, in terms of optical cable usage, it is possible to increase the efficiency by allowing a plurality of communication channels to be connected through a single optical cable between optical fiber termination devices.

3 is a diagram illustrating an optical network system between an optical line termination device (OLT) according to a second embodiment of the present invention.

Compared with the diagram shown in FIG. 2, the optical fiber terminators (OLTs) 100 and 200 have the same bidirectional optical transceivers forming a CWDM communication channel. However, the optical transmitters (first optical receiver, second optical receiver, .. 18th optical receiver) provided in the optical path terminator (OLT) 100,200 of FIG. 3 have the same wavelength as the transmission signal and the reception signal. The branch is characterized by forming a communication channel.

Hereinafter, an optical transmitter that forms a CWDM communication channel and uses the same wavelength in a transmission signal and a reception signal will be referred to as a CWDM same wavelength bidirectional optical transmitter.

[51] CWDM co-wavelength optical transceivers transmit light using linear

The same wavelength can be used for both the signal and the received signal. At this time, the CWDM co-wavelength optical transceiver uses the straightness of light to separate the transmission signal and the reception signal, so the reflection loss should be minimized when connecting the connector to the outside.

[52] CWDM equal wavelength bidirectionality in optical fiber termination (OLT) 100,200 If you have an optical transceiver, it is recommended that you use the APC (Angled Physical Contact) type.

As shown in Fig. 3, the optical fiber terminator (OLT) 10Q, 200 is equipped with a CWDM co-wavelength bidirectional optical transceiver to provide the first optical fiber terminator 100 and the low twelve optical fiber terminator 200. Once the optical network is established, the first and second optical fiber terminators 100,200 can be configured to use up to 18 communication channels.

[54] The first multiplexing / demultiplexing apparatus 300 and the second multiplexing / demultiplexing illustrated in FIG.

The function of the device 400 is as described above with reference to Fig. 2, except that the number of communication channels connected to the first and second optical fiber terminators 100 and 200 extends from 9 to 18 at most.

[55] CWDM same wavelength bidirectionality in the optical fiber termination device (OLT) in the present invention

The provision of an optical transceiver allows an optical fiber terminator (OLT) to have more communication channels, and the present invention communicates in the formation of an optical network between optical cable terminators (OLTs), even though the communication channel of the optical fiber terminators (OLTs) increases. The optical cable is not required as many as the number of channels, and one optical cable is used to form the optical network.

[56]

[57] The terms used in the present invention are merely used to describe specific embodiments.

The present invention is not intended to be limiting. The singular forms "a," "an," and "the" include plural expressions unless the context clearly dictates otherwise. Terms such as "include" or "have" in this application are described in the specification. To specify that a number, step, action, component, part, or combination thereof exists, or to determine the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof. It should be understood that it is not excluded beforehand.

Claims

Claim

A first optical fiber termination device existing in the first optical subscriber network in a time division passive optical communication network having a plurality of optical subscriber networks;

A second optical fiber termination device existing in the second optical subscriber network;

Receives transmission signals having a transmission wavelength set in each communication channel from a plurality of communication channels of the first optical fiber terminating device, and multiplies the received plurality of transmission signals and transmits them to one optical cable, or A first multiplexing and demultiplexing device for demultiplexing a received signal transmitted through the one optical cable and transmitting a signal corresponding to a reception wavelength of each communication channel to each communication channel of the first optical fiber termination device; and

The first multiplexer / demultiplexer transmits the received signal through the one optical cable and receives the received signal.

Demultiplexing transmits a signal corresponding to a reception wavelength of each communication channel to each communication channel of the second optical fiber terminator, or transmits a unique transmission wavelength set in each communication channel from a plurality of communication channels of the second optical fiber terminator. And a second multiplexing and demultiplexing device for receiving the received transmission signals and splitting the received plurality of transmission signals into wavelength division multiplexes and transmitting them to the single optical cable.

According to claim 1,

The first optical fiber terminating device and the second optical fiber terminating device include a plurality of optical transmitters for forming a communication channel, and the optical transmitters,

Optical network system between optical fiber terminators, which is a CWDM (Coarse Wavelength Division Multiplexing) communication channel and a bidirectional optical transmitter that forms a communication channel having a different wavelength between transmit and receive signals.

According to claim 1,

The first optical path terminating device and the second optical path terminating device include a plurality of optical transmitters for forming a communication channel, wherein the optical transmitters

Optical network system between optical fiber terminators, which is a CWDM (Coarse Wavelength Division Multiplexing) communication channel and a bidirectional optical transmitter / receiver that forms a communication channel in which transmit and receive signals have the same wavelength.

According to claim 3, The optical transmitter,

Optical network system between optical fiber terminators equipped with an APC (angled physical contact) type connector with an external optical cable connector.

[Claim 5] In paragraph 1,

The first multiplier and demultiplexer and the second multiplier and demultiplexer,

An optical network system between optical fiber terminators, consisting of an arrayed waveguide grating (AWG).

[Claim 6] In paragraph 1,

The first multiplexing and demultiplexing device and the second multiplexing and demultiplexing device,

Optical network system between optical fiber terminators consisting of thin film filters.