KR20140122549A - Optical signal transceiving network terminal device having optical switch for bypass function and optical network ethernet system including the same - Google Patents

Abstract

Disclosed is an optical signal transceiving network terminal device having a self bypass function performed when a failure occurs. The optical signal transceiving network terminal device comprises: an optical switch unit which performs at least a 2x2 optical switching function as a single switch during a normal operation, and which performs bypass switching in response to a failure generation control signal; a transceiver unit which receives an optical signal received through the optical switch unit, and transmits an optical signal for transmission through the optical switch unit; a failure detecting unit which detects a failure of the transceiver unit; and a controller which controls the transceiver unit, and applies the failure generation control signal to the optical switch unit when a failure detection signal is generated by the failure detecting unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical signal transmission / reception network terminal apparatus having an optical switch for bypassing, and an optical network transceiving network terminal device having the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of signal transmission and reception, and more particularly to an optical network transmission / reception network terminal apparatus and an optical network Ethernet system including the same.

In order to transmit and receive Ethernet signals such as digital broadcasting and Internet / VOD (Video On Demand), an Ethernet switch is usually provided in an optical signal transmitting / receiving network terminal device constituting an optical network Ethernet system.

The optical line terminal OLT serving as a center device and the optical network terminals ONT serving as an optical signal transmitting / receiving network terminal device can be connected to each other through one optical fiber line. Depending on the connection type, a ring-type, a Pont-to-Pont, or a tree connection structure is formed.

Generally, in order to simultaneously transmit and receive signals from one point to another, a transmission cable and a receiving cable must be separately provided. However, since the optical fiber cable itself has a wide bandwidth characteristic, a signal can be transmitted in both directions through one optical fiber line when the transmission band and the reception band are separated. However, in order to realize bidirectional optical communication with one optical fiber line, a device for separating the light emitted from the light emitting device and the light received by the light receiving device must be provided in the ONT.

Particularly, in the Ethernet communication implemented by a ring network, when data is transmitted in both directions using one optical fiber line, damage or cutting of the optical fiber line may occur, or an optical network terminal (ONT ), The optical network Ethernet system malfunctions.

SUMMARY OF THE INVENTION It is an object of the present invention to maintain optical communication in an optical network Ethernet system even when a failure related to transmission / reception of an optical signal in an optical signal transmission / reception network terminal apparatus or power off occurs.

According to an aspect of an embodiment of the present invention, an optical signal transmission / reception network terminal device includes:

An optical switch unit performing at least 2x2 optical switching function in normal operation and performing bypass switching in response to a failure occurrence control signal;

A transceiver unit for receiving an optical signal received through the optical switch unit and transmitting a transmission optical signal through the optical switch unit;

A fault detector for detecting a power-off of the transceiver unit or a fault related to transmission and reception of an optical signal; And

And a controller for controlling the transceiver unit and applying the fault occurrence control signal to the optical switch unit when a fault detection signal is generated from the fault detection unit.

According to an embodiment of the concept of the present invention,

A first switch for switching between a first optical input / output terminal and a first internal connection port;

A second switch for switching between the second optical input / output terminal and the second internal connection port;

And a third switch for switching between the first optical input / output terminal and the second optical input / output terminal to perform the bypass switching in response to the failure occurrence control signal.

According to an embodiment of the inventive concept, the transceiver section comprises:

A first transceiver connected between the second internal connection port and the controller for converting an upstream optical signal received through the optical switch unit into an electrical signal and converting a transmission signal to be output into the transmission optical signal;

And a second transceiver connected between the first internal connection port and the controller for converting a downstream optical signal received through the optical switch unit into an electrical signal and converting a transmission signal to be output into the transmission optical signal, have.

According to an embodiment of the present invention, when the power applied to the first and second transceivers is off or the intensity of the optical signal detected through the first and second transceivers is weaker than a preset intensity, A fault detection signal can be generated.

According to an embodiment of the concept of the present invention, the first optical input / output terminal may be connected to a single-core optical fiber for bidirectional communication.

According to an embodiment of the inventive concept, the second optical input / output terminal may be connected to a single-core optical fiber for bidirectional communication.

According to an embodiment of the inventive concept, the wavelengths used for the bidirectional communication may be 1310 nanometers and 1550 nanometers.

According to an embodiment of the present invention, the optical switch unit may be a 2x2 Ethernet optical switch for switching the broadcast signal and the Ethernet signal.

According to another aspect of an exemplary embodiment of the present invention, an optical network Ethernet system includes:

An optical line terminal (OLT) for providing an Ethernet signal;

At least two optical network terminals (ONTs) connected to the optical line terminal through an optical fiber,

Each of the optical network terminals includes at least a 2x2 optical switching function in a normal operation and includes an optical switch unit performing bypass switching in response to a failure occurrence control signal.

According to an embodiment of the inventive concept, the optical network terminals may constitute a ring network or a tree network for the optical line terminal.

According to an embodiment of the inventive concept, each optical network terminal comprises:

A transceiver unit for receiving an optical signal received through the optical switch unit and transmitting a transmission optical signal through the optical switch unit;

A fault detector for detecting a power-off of the transceiver unit or a fault related to transmission and reception of an optical signal; And

And a controller for controlling the transceiver unit and applying the failure occurrence control signal to the optical switch unit when a failure detection signal is generated from the failure detection unit.

According to the embodiment of the present invention, the optical communication of the optical network Ethernet system is performed through the normal optical signal transmitting / receiving network terminal devices by performing the bypass function of the single optical switch even when the optical signal transmitting / maintain. In addition, since only one optical switch is provided in the terminal device, the equipment implementation cost is reduced.

1 is a configuration block diagram of an optical networked Ethernet system according to a conceptual embodiment of the present invention;
Fig. 2 is an exemplary detailed configuration diagram of an optical signal transmitting / receiving network terminal device in Fig. 1; Fig.
Fig. 3 is a view showing a switching connection in the normal operation mode of the optical switch unit in Fig. 2; Fig.
Fig. 4 is a diagram showing a switching connection in the failure mode of the optical switch unit in Fig. 2. Fig.
Figure 5 is an exemplary detailed block diagram of the transceiver of Figure 2;
6 is an exemplary diagram illustrating a portion of the configuration of the transceiver of FIG. 5;
FIG. 7 is a diagram illustrating an example of the filtering operation of the wavelength division multiplexer WDM in FIG. 5; FIG.
8 is a flow chart of optical path switching of the controller of FIG. 2;

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more apparent from the following description of preferred embodiments with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art, without intention other than to provide an understanding of the present invention.

In this specification, when it is mentioned that some element or lines are connected to a target element block, it also includes a direct connection as well as a meaning indirectly connected to the target element block via some other element.

In addition, the same or similar reference numerals shown in the drawings denote the same or similar components as possible. In some drawings, the connection relationship of elements and lines is shown for an effective explanation of the technical contents, and other elements or circuit blocks may be further provided.

Each of the embodiments described and exemplified herein may also include complementary embodiments thereof, and it is to be understood that the basic operation of an optical network transmission / reception network terminal apparatus and an optical network Ethernet system including the optical network transmission / reception network terminal apparatus and functional circuits for transmitting and receiving optical signals of a network terminal apparatus Note that the details of the present invention are not described in detail in order to avoid obscuring the gist of the present invention.

1 is a block diagram of an optical network Ethernet system according to a conceptual embodiment of the present invention.

1, an optical network Ethernet system includes an optical line terminal (OLT) 100 for providing an Ethernet signal, at least two optical network terminals (ONTs) 200- 1,200-2,200-3,200-4,200-5,200-n).

The optical line terminal 100 (OLT) functions as a center device, converts an Ethernet signal such as digital broadcasting, Internet / video on demand, etc. into an optical signal and outputs the optical signal through an East (E) 101 terminal. Meanwhile, an optical line terminal (OLT) 100 receives an upstream optical signal through the East (E: 101) terminal connected to a single optical fiber line 10.

In FIG. 1, the optical network Ethernet system has a ring-type network connection structure by using a single optical fiber line. That is, the optical fiber lines 10, 11, 12, 13, 14, 15, and 16 form a ring structure with respect to the optical line terminal 100 (OLT).

For convenience, the direction of transmission from East to West indicates the forward direction, and the direction from West to East indicates the reverse direction. However, this is for the sake of convenience of explanation only with reference to FIG. 1, and in the case where the matters are different, the directions opposite to each other may be called forward and reverse directions.

Therefore, for example, when the optical fiber line 10 is cut or damaged in the ring network structure of FIG. 1 or the power of the first optical signal transmitting / receiving network terminal device 200-1 which is the optical network terminal (ONT) is turned off The optical communication of the optical network Ethernet system is no longer performed in both the upward and downward directions.

However, in the embodiment of the present invention, an optical switch for performing a bypass function is installed in the first optical signal transmitting / receiving network terminal 200-1, as shown in FIG. 2, so that normal optical signal transmitting / So that the optical communication of the optical network Ethernet system is maintained.

As a result, each optical network terminal includes an optical switch unit performing at least 2x2 optical switching function in the normal operation and performing bypass switching in response to the failure occurrence control signal.

1, power off occurs in the optical network terminal (ONT # 1: 200-1), but power off occurs in other optical network terminals such as the optical network terminal (ONT # 3: 200-3) It might be. Therefore, when power off occurs in the optical network terminal (ONT # 3: 200-3), bypass switching occurs only in the optical network terminal (ONT # 3: 200-3) 200-1, the normal switching operation is performed without the bypass switching operation.

On the other hand, when the optical fiber line 10 is cut or damaged, the optical network terminal (ONT # 1: 200-1) outputs the upstream optical signal (W) output from the West (W) 103 terminal of the optical line terminal Via the fiber optic line 11.

2 is an exemplary detailed configuration diagram of the optical signal transmitting / receiving network terminal device of FIG.

2, the optical signal transmitting / receiving network terminal apparatus 200-1 includes an optical switch unit 210, first and second transceivers 220 and 230, a fault / power off detection unit 240, and a controller 250, .

The optical switch unit 210 performs at least a 2x2 optical switching function in the normal operation and performs bypass switching in response to the failure occurrence control signal. Specifically, the optical switch unit 210 includes a first switch SW1, a second optical input / output terminal P4, and a second switch SW2 for switching between the first optical input / output terminal P1 and the first internal connection port P3. A second switch SW2 for switching between the first optical input / output terminal P1 and the second internal connection port P2, and a second switch SW2 for switching between the first optical input / output terminal P1 and the second optical switch And a third switch SW3 for switching between the input and output terminals P4.

Since only one optical switch unit 210 is provided in the optical signal transmission / reception network terminal device (for example, 200-1), the device is made compact and the implementation price is reduced.

The first optical input / output terminal P1 may indicate the West terminal, and the second optical input / output terminal P4 may indicate the East terminal.

Since only one optical switch unit 210 is installed inside the optical signal transmission / reception network terminal device, the product is made compact and the equipment implementation cost is reduced.

The transceiver unit including the first and second transceivers 220 and 230 receives an optical signal received through the optical switch unit 210 and transmits a transmission optical signal through the optical switch unit 210. The first transceiver 220 is connected between the second internal connection port P2 and the controller 250 to convert an upstream optical signal received through the optical switch unit 210 into an electrical signal, And converts the transmission signal to be transmitted into the transmission optical signal. The second transceiver 230 is connected between the first internal connection port P3 and the controller 250 to convert a downstream optical signal received through the optical switch 210 into an electrical signal, And converts the transmission signal to be transmitted into the transmission optical signal.

The fault detection unit including the fault / power off detection unit 240 detects occurrence of a fault in the transceiver unit. When the power applied to the first and second transceivers 220 and 230 is turned off or the intensity of the optical signal detected through the first and second transceivers 220 and 230 is weaker than a preset intensity, A detection signal can be generated.

The controller 250 controls the transceiver unit and applies the fault occurrence control signal to the optical switch unit 210 when a fault detection signal is generated from the fault detection unit 240.

2, the first optical input / output terminal P1 (W) may be connected to a single-core optical fiber 10 for bidirectional communication and the second optical input / output terminal P4 (E) may be connected to a single- (Not shown).

The wavelength used for the bidirectional communication may be, for example, 1310 nanometers and 1550 nanometers. Accordingly, when the first transceiver 220 receives the optical signal having the wavelength of 1550 nanometers in the first direction, it transmits the optical signal having the wavelength of 1550 nanometers in the second direction opposite to the first direction . Meanwhile, when the first transceiver 230 transmits the optical signal having the wavelength of 1550 nanometers in the first direction, the optical signal having the wavelength of 1550 nanometers can be received in the second direction.

2, the optical switch unit 210 is a 2x2 Ethernet optical switch for switching a broadcast signal and an Ethernet signal. However, the optical switch unit 210 is merely an example and may be an optical switch for switching other signals.

Fig. 3 is a diagram showing a switching connection in the normal operation mode of the optical switch unit in Fig. 2. Fig.

3, in the normal operation mode, the first switch SW1 of the optical switch unit 210 connects the ports P1 and P3 under the control of the controller 250 of FIG. 2, The second switch SW2 of the optical switch unit 210 connects the ports P2 and P4.

In response to the switching of the first switch SW1, an optical path is formed through the line L20 and an optical signal transmitted through the optical fiber line 10 is provided to the second transceiver 230. [ Therefore, when the wavelength of the optical signal transmitted in the first direction (for example, downward) of the line L20 is 1310 nanometers, for example, the second direction (for example, upward) of the line L20, Lt; RTI ID = 0.0 > 1550 < / RTI > nanometers.

 In response to the switching of the second switch SW2, a light path through the line L10 is formed and an optical signal transmitted through the optical fiber line 11 is provided to the first transceiver 220. [ Therefore, when the wavelength of the optical signal transmitted in the first direction (e.g., downward) of the line L10 is 1550 nanometers, for example, the second direction of the line L10 (for example, upward) For example, 1310 nanometers.

FIG. 4 is a diagram showing a switching connection in the failure mode of the optical switch unit in FIG. 2. FIG.

Referring to FIG. 4, the third switch SW3 of the optical switch unit 210 connects the ports P1 and P4 under the control of the controller 250 of FIG. 2 in the failure mode.

Thus, in the first direction, the optical signal received at the West is directly transmitted to the East without passing through the transceiver in the optical signal transmitting / receiving network terminal apparatus (for example, 200-1) .

In the second direction, the optical signal received by the East is directly transmitted to the West without passing through the transceiver in the optical signal transmitting / receiving network terminal apparatus (e.g., 200-1).

Figure 5 is an exemplary detailed block diagram of the transceiver of Figure 2;

5, the transceiver includes a multiplexer and demultiplexer 110, a laser diode driver 108, an amplifier 109, a laser diode section 102, a photodiode section 106, and a wavelength division multiplexer 104. [ . ≪ / RTI >

The wavelength division multiplexer 104 separates optical signals of 1310 nm and 1550 nm, which are two wavelengths used in the laser diode unit 102 and the photodiode unit 106, from each other.

The multiplexer / demultiplexer 110 may be connected to the controller 250 through a line L30. The wavelength division multiplexer 104 may be connected to the second switch SW2 via a line L10.

The laser diode driver 108 receives the signal output from the multiplexer / demultiplexer 110 and drives the laser diode unit 102.

The amplifier 109 receives a signal output from the photodiode unit 106, amplifies the amplified signal, and applies the amplified signal to the multiplexer / demultiplexer 110.

Although the example of the transceiver is shown in FIG. 5, the transceiver may be a smart duplex SFP small form-factor pluggable (SFP) transceiver, a smart BiDi SFP (bidirectional small form-factor pluggable) transceiver, a smart SWSF BiDi SFP fiber bidirectional small form-factor pluggable transceiver, SmartDuplex SFP + transceiver, Smart BiDi small form-factor pluggable plus (SFP +) transceiver, Smart SWSF BiDi SFP + (single wavelength single fiber bidirectional small form- factor pluggable plus transceiver, a 10 gigabit small form-factor pluggable (XFP) transceiver, a smart BiDi XFP (bidirectional 10 gigabit small form-factor pluggable) transceiver, or a smart SWSF BiDi XFP (single wavelength single fiber bidirectional 10 gigabit small form -factor pluggable) transceiver.

6 is an exemplary diagram showing a part of the configuration of the transceiver of FIG.

Referring to FIG. 6, the light emitting unit 102 may be implemented by the laser diode unit 102. That is, the light emitting unit 102 may be implemented as a light emitting diode (LED) or a laser diode (LD).

The light receiving unit 106 can be implemented with a photodiode, and thus corresponds to the photodiode unit 106. [

The optical filter 104 reflects a wavelength of, for example, 1550 nm, transmits the light to the light receiving unit 106, and transmits the wavelength of 1310 nm provided from the light emitting unit 102 to the outside.

Unlike the above case, the optical filter 104 reflects a wavelength of, for example, 1310 nm and transmits it to the light receiving unit 106. The optical filter 104 passes the wavelength of 1550 nm provided from the light emitting unit 102, It is a role to deliver.

Accordingly, the optical filter 104 corresponds to the wavelength division multiplexer 104 of FIG.

FIG. 7 is a diagram illustrating an example of a filtering operation of a wavelength division multiplexer (WDM) in FIG.

7, in the case where the optical thin film filter unit 104 corresponding to the WDM is a filter unit of 1310 nm, only a wavelength of 1310 nm out of a plurality of wavelengths applied to the incident end (C) . The remaining wavelengths may be reflected at the reflection end (R). Therefore, a wavelength of 1550 nm can appear at the reflection (R).

On the other hand, unlike the case described above, when the optical thin film filter unit 104 corresponding to the WDM is a filter unit of 1550 nm, only a wavelength of 1550 nm among a plurality of wavelengths applied to the incident end (C) And is output to the division (I). The remaining wavelengths may be reflected at the reflection end (R). Therefore, a wavelength of 1310 nm can appear at the reflection end (R).

8 is an optical path switching flowchart of the controller of FIG.

Referring to FIG. 8, in step S800, the controller 250 of FIG. 2 performs initialization of each functional block circuit, and receives optical signals applied in the first and second directions in step S810.

In step S820, the controller 250 checks whether an error has occurred in the single optical fiber line or whether the power applied to the transceiver unit is off. When the fault detection unit 240 detects a power-off of the transceiver unit or a fault related to optical signal transmission / reception, a fault detection signal is generated and applied to the controller 250.

Therefore, if a failure occurs, bypass control in step S830 is performed. In step S830, the controller 250 applies a failure occurrence control signal to the optical switch unit 210. [ Thereby, the third switch SW3 is switched on, and the connection as shown in Fig. 4 is established.

The bypass control is maintained until the generated fault is automatically or manually recovered.

In step S840, the presence or absence of recovery is checked, and when the recovery is made, the normal control in step S850 is performed as it is. That is, in step S850, the switching operation is performed as shown in FIG. In this case, the bypass control operation is released.

According to the embodiment of the present invention, the optical communication of the optical network Ethernet system is maintained through the normal optical signal transmitting / receiving network terminal devices by performing the bypass function of the optical switch even when the optical signal transmitting / do.

The application of the present invention is not limited to the FTTH (Fiber To The Home) method. In addition, although a communication method using a single optical cable has been described, taking advantage of the fact that the bandwidth of the optical cable is sufficiently large considering that the voice telephone service, the internet service, and the cable broadcasting service are provided to the respective homes through different lines, The above three services may be provided as a pair of optical cables. That is, since a plurality of signals can be simultaneously transmitted to one optical cable, bidirectional voice data transmission / reception, internet data transmission / reception, and cable broadcasting reception are all possible with a pair of optical cables.

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. For example, when the matter is different, changes and modifications can be made to the detailed configuration of the optical switch or the internal connection configuration of the terminal device without deviating from the technical idea of the present invention.

Description of the Related Art [0002]
100: Optical line terminal
200-1: Optical Network Terminal
210: Optical switch section
220: first transceiver
230: second transceiver
250: controller

Claims (16)

An optical switch unit performing at least 2x2 optical switching function in normal operation and performing bypass switching in response to a failure occurrence control signal;
A transceiver unit for receiving an optical signal received through the optical switch unit and transmitting a transmission optical signal through the optical switch unit;
A fault detector for detecting a power-off of the transceiver unit or a fault related to transmission and reception of an optical signal; And
And a controller for controlling the transceiver unit and applying the fault occurrence control signal to the optical switch unit when a fault detection signal is generated from the fault detection unit.
The optical switch according to claim 1,
A first switch for switching between a first optical input / output terminal and a first internal connection port;
A second switch for switching between the second optical input / output terminal and the second internal connection port;
And a third switch for switching between the first optical input / output terminal and the second optical input / output terminal to perform the bypass switching in response to the failure occurrence control signal.
3. The transceiver of claim 2,
A first transceiver connected between the second internal connection port and the controller for converting an upstream optical signal received through the optical switch unit into an electrical signal and converting a transmission signal to be output into the transmission optical signal;
And a second transceiver connected between the first internal connection port and the controller for converting a downstream optical signal received through the optical switch unit into an electrical signal and converting a transmission signal to be outputted into the transmission optical signal, A signal transmission / reception network terminal device.
4. The apparatus of claim 3, wherein the fault detector detects the fault signal when the power applied to the first and second transceivers is off or the intensity of the optical signal detected through the first and second transceivers is less than a predetermined intensity Wherein the optical signal transmission / reception network terminal device generates the optical signal.
5. The terminal of claim 4, wherein the first optical input / output terminal is connected to a single-core optical fiber for bidirectional communication.
5. The terminal of claim 4, wherein the second optical input / output terminal is connected to a single-core optical fiber for bidirectional communication.
6. The terminal of claim 5, wherein the wavelengths used for bidirectional communication are 1310 nanometers and 1550 nanometers.
The terminal apparatus of claim 2, wherein the optical switch unit is a single 2x2 Ethernet optical switch for switching a broadcast signal and an Ethernet signal.
An optical line terminal (OLT) for providing an Ethernet signal;
At least two optical network terminals (ONTs) connected to the optical line terminal through an optical fiber,
Wherein each of the optical network terminals includes at least a 2x2 light switching function in a normal operation and an optical switch unit performing bypass switching in response to a failure occurrence control signal.
10. The optical networked Ethernet system of claim 9, wherein the optical network terminals comprise a ring or tree network for the optical line terminal.
10. The optical network terminal of claim 9,
A transceiver unit for receiving an optical signal received through the optical switch unit and transmitting a transmission optical signal through the optical switch unit;
A fault detector for detecting a power-off of the transceiver unit or a fault related to transmission and reception of an optical signal; And
Further comprising a controller for controlling the transceiver unit and for applying the fault occurrence control signal to the optical switch unit when a fault detection signal is generated from the fault detection unit.
The optical switch according to claim 11,
A first switch for switching between a first optical input / output terminal and a first internal connection port;
A second switch for switching between the second optical input / output terminal and the second internal connection port;
And a third switch for switching between the first optical input / output terminal and the second optical input / output terminal to perform the bypass switching in response to the failure occurrence control signal.
12. The apparatus of claim 11, wherein the transceiver unit comprises:
A first transceiver connected between the second internal connection port and the controller for converting an upstream optical signal received through the optical switch unit into an electrical signal and converting a transmission signal to be output into the transmission optical signal;
And a second transceiver connected between the first internal connection port and the controller for converting a downstream optical signal received through the optical switch unit into an electrical signal and converting a transmission signal to be outputted into the transmission optical signal, Network Ethernet system.
14. The apparatus of claim 13, wherein the fault detector detects the fault signal when the power applied to the first and second transceivers is off or the intensity of the optical signal detected through the first and second transceivers is less than a preset intensity Generating optical network Ethernet systems.
The optical networked Ethernet system of claim 12, wherein the first and second optical input / output terminals are connected to a single core optical fiber for bidirectional communication.
16. The optical networked Ethernet system of claim 15, wherein the wavelengths used for bidirectional communication are 1310 nanometers and 1550 nanometers.

Images