KR20130007284A - Passive optical network and the method of detecting ont - Google Patents

Abstract

PURPOSE: A PON(Passive Optical Network) system and an ONT(Optical Network Terminal) abnormality detecting method for the same are provided to detect an optical signal of a virtual terminal section and to detect a failure ONT. CONSTITUTION: A plurality of ONT terminals(140) includes at least one virtual ONT terminal. The virtual ONT terminal outputs an optical signal in a time slot interval according to a time division access control type. An OLT(Optical Line Terminal)(100) receives the optical signal outputted according to time division access control mode. The OLT detects an optical power value of the virtual ONT terminals. The OLT detects abnormal state ONT. [Reference numerals] (130) Splitter

Description

PONIVE system and method for detecting ONT error thereof {PASSIVE OPTICAL NETWORK AND THE METHOD OF DETECTING ONT}

The present invention relates to a PON system and an ONT abnormality detection method. In particular, a virtual terminal is formed in a plurality of ONT terminals connected to an optical line terminator to detect a faulty ONT that detects an optical signal in a virtual terminal section and outputs a continuous signal. The present invention relates to a PON system and an ONT abnormality detection method.

Recently, as Internet users using wireless communication have rapidly increased, high-speed Internet technologies have been developed to provide faster Internet services to users.

The wireless LAN technology is a typical technology for such a high speed Internet service.

An optical communication system is a system for transmitting and receiving data based on an optical signal. An optical transmission line terminator of a station is a device for relaying data transmission between a server providing various data services to a subscriber through a telephone network or an internet network and optical network terminals connected to each subscriber terminal. The optical path terminator transmits the transmission data of the server to the target optical network terminal, and forms an optical signal for receiving the transmission data of the target optical network terminal.

In general, a passive optical network (PON) is an optical subscriber construction method that provides an optical fiber-based high-speed service to an enterprise or a home, and an optical fiber terminal device (ONT) at the bottom of the This is how you can connect. At this time, the TDM-PON using a time division multiplexing scheme distributes or distributes the downstream optical signal to the subscribers, and combines the upstream optical signals from the subscribers.

In the passive optical network using time division multiplexing, the data transmission / reception method between the optical line terminator and the optical network terminal is performed by inserting the identifier of the optical network terminal to which the optical line terminator is registered in the preamble of the frame. Sends only frames with their identifiers to the user interface. On the other hand, in the upstream, when the fiber terminator dynamically allocates an upstream time slot to all the fiber terminals, each fiber terminator transmits data to the fiber terminator during the time slot allocated to the tall.

However, although the optical terminals must perform upstream only during the assigned time slots, a failure occurs in one optical terminal and a continuous signal is transmitted, thereby causing an overall communication failure.

The technical problem to be solved by the present invention is to form a virtual terminal on a plurality of ONT terminals connected to the optical line termination device PON system and ONT that can detect the failure ONT to output the continuous signal by detecting the optical signal of the virtual terminal section An abnormality detection method is provided.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an aspect of the present invention, there is provided a PON system for detecting an ONT abnormality, comprising: a plurality of ONT terminals including at least one virtual ONT terminal for outputting an optical signal in a time slot interval allocated according to a time division access control scheme; And an optical line terminator for receiving an optical signal output according to a time division access control scheme from the plurality of ONT terminals and detecting an ONT in an abnormal state.

The optical line terminator includes: an MCU which assigns a unique Logical Link ID (LLID) and a Virtual Logical Link ID (V-LLID) to the plurality of ONT terminals and a virtual ONT terminal; An optical receiver for receiving an optical signal from the ONT terminals; A photoelectric converter converting the optical signal received from the optical receiver into an electrical signal; An optical monitoring unit converting a signal converted into an electrical signal in the photoelectric conversion unit into a digital signal to detect optical power; A database unit for storing optical power data for the ONT terminals; And a control unit for allocating an allocation time corresponding to each time schedule of the ONT terminals, and determining whether there is an abnormal state ONT terminal by comparing the optical power data detected by the optical monitoring unit with the optical power data of the database unit. It has that feature.

Here, the control unit is characterized in that it determines the presence or absence of the ONT terminal in the abnormal state according to the detection of the optical signal in the time slot period allocated to the virtual ONT terminal.

Here, it is characterized in that it is determined that there is an ONT terminal in an abnormal state when the optical power magnitude of the optical signal is greater than or equal to a predetermined value in the section allocated to the virtual ONT terminal.

Here, the virtual ONT terminal is characterized in that it is formed for every Nth order that the ONT terminals are sequentially arranged.

Moreover, the ONT abnormality detection method of the PON system which concerns on this invention WHEREIN: The optical line termination device of a passive optical network (PON) WHEREIN: A unique Logical Link ID (LLID) is provided to each ONT terminal and a virtual ONT terminal from an optical line termination device. Being assigned; Setting a time slot to output an optical signal to each ONT terminal and a virtual ONT terminal according to a time division access control scheme; Detecting an optical signal of a time slot interval allocated to the virtual ONT terminal; And determining an abnormal state of the ONT terminals when the optical power value detected in the virtual ONT terminal section is equal to or greater than a predetermined size.

Here, the time slot section of the virtual ONT terminal is characterized in that the time slot section of the ONT terminals are formed every Nth sequentially arranged.

According to the present invention, it is possible to form a virtual terminal in a plurality of ONT terminals connected to the optical line terminator and to detect a failure signal ONT which outputs a continuous signal by detecting an optical signal in a virtual terminal section, thereby quickly taking measures on system failure. Can provide services.

1 is a view schematically showing the configuration of a PON system for detecting ONT abnormalities of the present invention.
2 is a diagram schematically showing the configuration of a PON module of the optical line termination device of the present invention.
3 is a diagram illustrating detection of optical power values in an ONT terminal section and a virtual terminal section of the present invention.
4 shows output of a continuous optical signal due to a fault ONT;
5 is a flowchart illustrating a method for detecting ONT anomaly of a PON system according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing in detail the operating principle of the preferred embodiment of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The same reference numerals are used for portions having similar functions and functions throughout the drawings.

In addition, in the entire specification, when a part is referred to as being 'connected' to another part, it may be referred to as 'indirectly connected' not only with 'directly connected' . Also, to include an element does not exclude other elements unless specifically stated otherwise, but may also include other elements.

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

1 is a view schematically showing the configuration of a PON system of the present invention. As shown in FIG. 1, the PON system includes a plurality of ONT terminals 140 including at least one virtual ONT terminal that outputs an optical signal in each allocated section according to a time division access control scheme, and the ONT terminal. The optical line termination device 100 receiving the optical signal output according to the time division access control method to the field 140 and detecting the optical power value of the time slot section allocated to the virtual ONT terminal to detect the presence of an abnormal state ONT. Include.

Here, the optical line terminator 100 is provided with at least one PON module 120, each PON module 120 using a splitter 130 in the optical cable to connect with the ONT terminals 140 A plurality of ONT terminals 140 may be connected to the PON device 120 of FIG.

In general, the optical line terminator 100 performs a communication function because it performs a communication function. For example, in the E-PON network, since a bi-directional communication is performed using a single optical fiber, data communication is performed by applying optical signals having two different wavelengths (1490 nm / 1310 nm). In such an E-PON network, Internet data communication is performed by applying 1490 nm as a downstream optical signal (output part of the transmitter) and 1310 nm as an upstream optical signal (transmitter).

The ONT terminals 140 are each assigned a unique Logical Link ID (LLID) from the MCU 110 of the optical line terminator 100. At this time, the # V1 ONT 144 is virtually assigned a Virtual LLID (V-LLID), where the assigned Logical Link ID (LLID) establishes a logical link between one ONT and an optical line terminator. This applies to a specific Service Level Agreement (SLA) agreement.

In more detail, the virtual ONT terminal 144 may be formed every Nth time where the ONT terminals 141, 142, and 143 are sequentially arranged. That is, # 1 ONT, # 2 ONT, # 3 ONT, # V1 ONT, # 5 ONT, # 6 ONT, # 7 ONT, # V2 ONT, # 9 ONT, # 10 ONT, # 11 ONT, # V3 ONT. May be assigned sequentially. Therefore, # 1 ONT, # 2 ONT, # 3 ONT, and # V1 ONT may be divided into one grouping. For example, if 64 ONTs can be connected to one PON device, it can be divided into 16 groups having virtual ONTs 144 corresponding thereto. At this time, the order in which the virtual ONT 144 is arranged can be changed as necessary.

In addition, time slots are allocated to # 1 ONT 141, # 2 ONT 142, # 3 ONT 143, and # V1 ONT 144 of the ONT terminal 140 to receive an optical signal. Each of the ONT terminals is provided with an optical transmission / reception module to up / down stream the optical line termination device and the optical signal.

2 is a diagram schematically showing the configuration of a PON module of the optical line terminator of the present invention. As shown in FIG. 2, the PON module 120 includes an optical receiver 201, a photoelectric converter 202, an optical monitor 203, a database 205, and a controller 204. It is composed.

The optical receiver 201 receives an optical signal from the ONT terminals 140. Here, the light receiving unit 201 is preferably composed of a photo diode. In addition, the ONT terminals 140 may further include an optical transmitter (not shown) for upstreaming an optical signal, and the optical receiver 201 and the transmitter may be implemented as one optical transceiver module. .

The photoelectric converter 202 converts the optical signal received by the optical receiver 201 into an electrical signal.

The optical monitoring unit 203 detects optical power by converting a signal converted into an electrical signal in the photoelectric conversion unit 202 into a digital signal.

The database 205 stores data for the ONT terminals 140. That is, data such as unique Logical Link ID (LLID), optical power output value, product information, and temperature for each ONT terminal are stored.

The control unit 204 distributes time slots corresponding to the time schedules of the ONT terminals 140, and transmits the optical power data detected by the optical monitoring unit 203 to the optical power data of the database 205. It is determined whether there is an abnormal state ONT terminal in comparison with.

More specifically, the controller 204 determines whether there is an ONT terminal in an abnormal state according to whether an optical signal is detected from a time slot section allocated to the virtual ONT terminal 144, and the virtual ONT terminal V1 ( If the optical power size of the optical signal is greater than or equal to a predetermined value in the time slot period allocated to 144, it is determined that there is an ONT terminal in an abnormal state.

3 is a diagram illustrating the detection of the optical power value between the ONT terminal section and the virtual terminal section of the present invention. As shown in FIG. 3, the optical line terminator 100 receives an optical signal by allocating time slots to # 1 ONT, # 2 ONT, # 3ONT, and # V1 ONT, respectively. Here, # V1 ONT is virtually assigned a V-LLID (Virtual LLID).

4 is a diagram showing output of a continuous optical signal due to a fault ONT. As shown in FIG. 4, when # 1 ONT fails, for example, # 1 ONT, # 2 ONT, or # 3 ONT, the # 1 ONT continues to monopolize the optical line by outputting an optical signal. . This is because the laser is always on regardless of the laser control signal due to the failure of the optical module, or the laser of the optical module is always on due to a malfunction of the laser control signal of a specific ONT, or the laser control signal and the control signal input of the optical module are mutually different. If set to the opposite, one ONT takes over the time slots of the entire upstream, while the OLT cannot deregister all ONTs and assumes that all ONTs are not responding correctly, as well as bad ONTs. Block access.

Therefore, the optical power value of the optical signal of the time slot of the ONT terminals 140 and the time slot of the virtual ONT terminal 144 is detected to determine whether there is an abnormal state ONT terminal.

That is, when the optical power magnitude of the optical signal is greater than or equal to a predetermined value in the time slot period allocated to the virtual ONT terminal V1, it may be determined that the output of the optical signal by the ONT terminal in an abnormal state is continued.

5 is a flowchart illustrating a method for detecting ONT anomaly of a PON system according to the present invention. As shown in FIG. 5, in the method for detecting ONT abnormality of the PON system according to the present invention, first, a unique Logical Link ID (LLID) is assigned to each ONT terminal and a virtual ONT terminal from an optical line terminator (step 1). S501).

The ONT terminals 140 are each assigned a unique Logical Link ID (LLID) from the fiber termination device. At this time, the # V1 ONT is virtually assigned a virtual LLID.

In more detail, the virtual ONT terminal may be formed every Nth times the ONT terminals are sequentially arranged. For example, # 1 ONT, # 2 ONT, # 3 ONT, # V1 ONT, # 5 ONT, # 6 ONT, # 7 ONT, # V2 ONT, # 9 ONT, # 10 ONT, # 11 ONT, # V3 ONT ... etc. can be assigned sequentially. As such, when the V-LLIDs of the virtual terminals are allocated to each other, # 1 ONT, # 2 ONT, # 3 ONT, and # V1 ONT may be divided into one grouping. For example, if you can connect # 64 ONTs to one PON device, it can be divided into 16 groups with virtual ONTs corresponding to them. At this time, the order in which the virtual ONTs are arranged can be changed as necessary.

In operation S502, a time slot is set to output an optical signal to each ONT terminal and a virtual ONT terminal according to a time division access control scheme.

Here, time slots are allocated to each ONT terminal and a virtual ONT terminal in correspondence with each time schedule.

In operation S503, an optical signal of a time slot interval allocated to the virtual ONT terminal is detected. That is, the optical signal is detected from the time slot section allocated to each of the ONT terminals and the virtual ONT terminals.

Subsequently, when the optical power value of the optical signal detected in the virtual ONT terminal section is equal to or greater than a predetermined size (S504), an abnormal state of the ONT terminals is determined (S505). Here, the presence or absence of the abnormal state ONT terminal is determined by comparing the optical power data of the detected optical signal with the optical power data of the database unit. The optical power values for the optical signals of the respective ONT terminals may have a predetermined difference, and these are previously compared with the database values. In addition, it is determined whether an optical signal is detected in a time slot allocated to the virtual ONT terminal.

Specifically, it is determined whether there is an ONT terminal in an abnormal state according to whether the optical signal of the time slot section allocated to the virtual ONT terminal is detected, and the optical power size of the optical signal is predetermined in the time slot section allocated to the virtual ONT terminal. If the value is over, it is determined that there is an ONT terminal in an abnormal state. For example, if any one of # 1 ONT, # 2 ONT, or # 3 ONT fails and the output of the optical signal continues, the optical signal is monopolized in the time slot section assigned to the virtual ONT terminal because the optical line is monopolized. Is detected. That is, the ONT terminals determine that the normal state should be no light detection in the time slot period allocated to the virtual ONT terminal.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of course, this is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the equivalents as well as the claims that follow.

Description of the Related Art
100 --- Fiber Terminator 120 --- PON Module
140 --- ONT 201 --- Optical Receiver
202 --- photoelectric conversion unit 203 --- optical monitoring unit
204 --- Controls 205 --- Database

Claims (7)

A plurality of ONT terminals including at least one virtual ONT terminal for outputting an optical signal in an allocated time slot interval according to a time division access control scheme;
An optical line terminator for receiving an optical signal output according to a time division access control scheme from the plurality of ONT terminals and detecting an optical power value of a time slot section allocated to the virtual ONT terminal to detect an abnormal state ONT; PON system, characterized in that.
The method of claim 1,
The optical line terminator,
An MCU which assigns a unique Logical Link ID (LLID) and a Virtual Logical Link ID (V-LLID) to the plurality of ONT terminals and the virtual ONT terminal;
An optical receiver for receiving an optical signal from the ONT terminals;
A photoelectric converter converting the optical signal received from the optical receiver into an electrical signal;
An optical monitoring unit converting a signal converted into an electrical signal in the photoelectric conversion unit into a digital signal to detect optical power;
A database unit for storing optical power data for the ONT terminals;
A control unit for allocating time slots corresponding to each time schedule of the ONT terminals, and determining whether there is an abnormal state ONT terminal by comparing the optical power data detected by the optical monitoring unit with the optical power data of the database unit. PON system, characterized in that.
The method of claim 2,
The controller determines whether there is an ONT terminal in an abnormal state according to whether an optical signal is detected from a time slot section allocated to the virtual ONT terminal.
The method of claim 3,
The PON system, characterized in that it is determined that there is an ONT terminal in an abnormal state when the optical power magnitude of the optical signal is more than a predetermined value in the time slot interval allocated to the virtual ONT terminal.
The method of claim 1,
The virtual ONT terminal is a PON system, characterized in that formed for every N-th order that the ONT terminals are sequentially arranged.
Allocating a unique Logical Link ID (LLID) and a Virtual Logical Link ID (V-LLID) to the plurality of ONT terminals and the virtual ONT terminal;
Setting a time slot to output an optical signal to each ONT terminal and a virtual ONT terminal according to a time division access control scheme;
Detecting an optical signal of a time slot interval allocated to the virtual ONT terminal;
And determining an abnormal state of the ONT terminals when the optical power value detected in the allocated time slot period of the virtual ONT terminal is equal to or greater than a predetermined size.
The method according to claim 6,
And a time slot section of the virtual ONT terminal is formed every Nth time slot sections of the ONT terminals are sequentially arranged.

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