JP2005203868A - PON relay device and PON system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PON-relaying apparatus and a PON system, whereby the number of accommodated ONUs in an OLT can be increased. <P>SOLUTION: Upon the receipt of an optical signal through a VC connection from an optional ONU, the PON-relaying apparatus converts the optical signal into an electrical signal and stores the electrical signal to a queue buffer section 14; and upon the receipt of a signal transmission request from the OLT 4 through a VP connection, the PON-relaying apparatus converts the electrical signal stored in the queue buffer section 14 into the optical signal and transmits the optical signal to the OLT 4 through the VP connection. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, one station side device (OLT: Optical Line Terminal) and N network terminators (ONU: Optical Network Unit) are connected by optical fiber, and one OLT and N ONUs are PON ( The present invention relates to a PON system that transmits and receives optical signals according to the Passive Optical Network) protocol, and a PON relay device that relays optical signals transmitted and received by one OLT and N ONUs.

Regarding the ATM-PON system, ITU-T G.C. 983.1, in the PON system, the OLT is connected to an optical branch coupler via an optical fiber, and the optical branch coupler is connected to N ONUs via an optical fiber (for example, , See Patent Document 1).
In addition, the number of branches of the optical fiber in the optical branching coupler is ITU-T GG. 983.1 specifies a maximum of 32 branches for reasons such as light loss and logical limitations.
In addition, ITU-T G.I. 983.1 stipulates that the transmission distance between the OLT and the ONU is 20 km at maximum.

JP 2000-36828 A (paragraph numbers [0009] to [0033], FIG. 1)

Since the conventional PON system is configured as described above, the maximum number of ONUs that can accommodate one OLT is limited to 32. If the number of ONUs exceeds 32, it is necessary to add more OLTs. There was a problem.
In addition, since the transmission distance between the OLT and the ONU is limited to a maximum of 20 km, the service range in which the ONU can transmit and receive optical signals to and from the OLT is narrowed. To expand the service range, it is necessary to increase the number of installed OLTs. There was also a problem.

The present invention has been made to solve the above-described problems, and an object thereof is to obtain a PON relay device and a PON system that can increase the number of ONUs accommodated in an OLT.
Another object of the present invention is to obtain a PON relay device and a PON system that can expand the service range without increasing the number of installed OLTs.

  The PON repeater according to the present invention, when receiving an optical signal through a VC connection from an arbitrary network terminating device among a plurality of network terminating devices, converts the optical signal into an electrical signal and stores it in a buffer; When a signal transmission request is received from the side device through the VP connection, the electrical signal stored in the buffer is converted into an optical signal, and the optical signal is transmitted to the station side device through the VP connection.

  According to the present invention, when an optical signal is received through a VC connection from an arbitrary network termination device among a plurality of network termination devices, the optical signal is converted into an electrical signal and stored in the buffer, while the station side device receives VP. When the signal transmission request is received through the connection, the electrical signal stored in the buffer is converted into an optical signal, and the optical signal is transmitted to the station side device through the VP connection. There is an effect that the number of devices accommodated can be increased.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a PON system according to Embodiment 1 of the present invention. In the figure, a subscriber-side network terminator (hereinafter referred to as ONU: Optical Network Unit) 1-1 to 1-N, 2- 1-2-N and 3-1 to 3-2 convert ATM cells containing various control information and data into optical signals, and the optical signals are transmitted to a transmission line termination device (hereinafter referred to as OLT: Optical). While transmitting to 4), the optical signal transmitted from the OLT 4 is received.
When the OLT 4 collects optical signals transmitted from the ONUs 1-1 to 1-N, the OLT 4 collects the optical signals from the PON relay device 8 by transmitting a signal transmission request to the PON relay device 8, and converts the optical signals into electrical signals. Converted to a signal and sent to the upper network side. The OLT 4 receives optical signals transmitted from the ONUs 2-1 to 2-N and 3-1 to 3-2, converts them into electrical signals, and transmits the electrical signals to the upper network side. Further, when the OLT 4 receives an electrical signal transmitted from the upper network side, the OLT 4 converts the electrical signal into an optical signal, and converts the optical signal into the ONU 1-1 to 1-N, 2-1 to 2-N, 3-1. Send to ~ 3-2.

  The optical branching coupler 5 is connected to the ONUs 1-1 to 1-N via an optical fiber and is connected to the PON relay device 8 via an optical fiber to branch an optical signal transmitted from the PON relay device 8. The optical signals transmitted from the ONUs 1-1 to 1-N are combined and output to the PON repeater 8. The optical branching coupler 6 is connected to the ONUs 2-1 to 2-N via optical fibers, and is connected to the OLT 4 via optical fibers, and branches optical signals transmitted from the OLT 4 to divide ONUs 2-1 to 2-1. While outputting to -N, the optical signals transmitted from the ONUs 2-1 to 2-N are combined and output to the OLT 4. The optical splitter / coupler 7 is connected to the ONUs 3-1 to 3-2 and the PON repeater 8 via optical fibers, and is connected to the OLT 4 via optical fibers to branch the optical signal transmitted from the OLT 4 The optical signals transmitted from the ONUs 3-1 to 3-2 and the PON relay device 8 are combined and output to the OLT 4 while being output to the ONUs 3-1 to 3-2 and the PON relay device 8.

  When the PON relay device 8 receives an optical signal from an arbitrary ONU among the ONUs 1-1 to 1-N, the optical signal is converted into an electric signal and stored in a buffer, and when a signal transmission request is received from the OLT 4 The electrical signal stored in the buffer is converted into an optical signal, and the optical signal is transmitted to the OLT 4. When the PON relay device 8 receives an optical signal from the OLT 4, it terminates the optical signal, identifies the transfer destination ONU, and transfers the optical signal to the transfer destination ONU through the VC connection corresponding to the ONU. .

FIG. 2 is a configuration diagram showing the PON relay device 8 according to the first embodiment of the present invention. In the figure, the wavelength demultiplexing unit 11 is connected to the ONUs 1-1 to 1-N via a VC (Virtual Circuit) connection. By detecting the wavelength (eg, 1.3 micron wavelength) of the upstream optical signal (the optical signal transmitted from the ONU 1-1 to 1-N) from the optical signal on the VC connection, the light on the VC connection is detected. The upstream optical signal is separated from the signal and output to the optical receiver 12, while the downstream optical signal transmitted from the optical transmitter 19 is multiplexed with the optical signal on the VC connection.
When receiving the upstream optical signal from the wavelength multiplexing / demultiplexing unit 11, the optical receiving unit 12 converts the optical signal into an electrical signal. The PON protocol termination unit 13 terminates the PON protocol with respect to the electrical signal converted by the optical reception unit 12 and stores the electrical signal in the waiting buffer unit 14.
The wavelength demultiplexing unit 11, the optical receiving unit 12, and the PON protocol termination unit 13 constitute a receiving unit.

The wavelength demultiplexing unit 15 is connected to the OLT 4 via a VP (Virtual Path) connection, and the wavelength (for example, 1.5 micron) of the optical signal downstream from the optical signal on the VP connection (the optical signal transmitted from the OLT 4). By detecting the wavelength), the downstream optical signal is separated from the optical signal on the VP connection and output to the optical receiver 16, while the upstream optical signal transmitted from the optical transmitter 18 is transmitted to the optical signal on the VP connection. Multiplex to signal. When receiving the downstream optical signal from the wavelength multiplexing / demultiplexing unit 15, the optical receiving unit 16 converts the optical signal into an electrical signal.
The PON protocol termination unit 17 terminates the PON protocol with respect to the electrical signal converted by the optical receiving unit 16, and if the electrical signal is a signal transmission request, the electrical signal stored in the waiting buffer unit 14 is optically transmitted. To the unit 18. If the electrical signal is a transmission signal for the ONUs 1-1 to 1-N, the PON protocol termination unit 17 outputs the electrical signal to the PON protocol termination unit 13.
The optical transmission unit 18 converts the electrical signal output from the PON protocol termination unit 17 into an optical signal and outputs the optical signal to the wavelength demultiplexing unit 15.
The wavelength demultiplexing unit 15, the optical receiving unit 16, the PON protocol termination unit 17, and the optical transmitting unit 18 constitute a transmitting unit.

When receiving the electrical signal from the PON protocol termination unit 13, the optical transmission unit 19 converts the electrical signal into an optical signal and outputs it to the wavelength demultiplexing unit 11.
The wavelength multiplexing / demultiplexing units 11 and 15, the optical receiving unit 16, the PON protocol termination units 13 and 17 and the optical transmitting unit 19 constitute transfer means.
However, when the PON relay device 8 does not handle the downlink signal transmitted from the OLT 4, the transfer means is not necessary.

Next, the operation will be described.
As shown in FIG. 3, the PON relay device 8 and the ONUs 3-1 to 3-2 and the OLT 4 in the PON system are logically connected by a VP connection, and the PON relay device 8 and the ONUs 1-1 to 1-N are Logically, they are connected by a VC connection.
These physical connections are connected via optical fibers as shown in FIG.

First, when the ONUs 1-1 to 1-N on the subscriber side need to transmit ATM cells to the higher network side, the ATM cells, which are electrical signals, are converted into optical signals (hereinafter referred to as upstream optical signals).
Then, the ONUs 1-1 to 1-N transmit the upstream optical signal to the PON relay device 8 through the VC connection assigned to itself. That is, the ONUs 1-1 to 1-N modulate the wavelength of the upstream optical signal to 1.3 microns, for example, and multiplex the upstream optical signal with the optical signal on the VC connection.

The wavelength demultiplexing unit 11 of the PON repeater 8 detects the wavelength of the upstream optical signal (for example, a wavelength of 1.3 microns) from the optical signal on the VC connection, and thereby detects the upstream of the optical signal on the VC connection. The optical signal is separated and output to the optical receiver 12.
When receiving the upstream optical signal from the wavelength demultiplexing / separating unit 11, the optical receiving unit 12 of the PON repeater 8 converts the optical signal into an electrical signal.
When the optical receiver 12 converts the upstream optical signal into an electrical signal, the PON protocol termination unit 13 of the PON relay device 8 performs the termination of the PON protocol for the electrical signal and stores the electrical signal in the waiting buffer unit 14. To do.
The electrical signal is stored in the waiting buffer unit 14 until the PON relay device 8 receives a signal transmission request from the OLT 4 as will be described later.

When the OLT 4 needs to collect optical signals transmitted from the ONUs 1-1 to 1-N, the OLT 4 converts an ATM cell including a signal transmission request into an optical signal (hereinafter referred to as a downstream optical signal) and transmits it through a VP connection. The downstream optical signal is transmitted to the PON relay device 8. That is, the OLT 4 modulates the wavelength of the downstream optical signal to 1.5 microns, for example, and multiplexes the downstream optical signal with the optical signal on the VP connection.
Note that the transmission timing of the signal transmission request to the PON relay device 8 may be regular or irregular.

The wavelength demultiplexing unit 15 of the PON repeater 8 detects the wavelength of the downstream optical signal (for example, a wavelength of 1.5 microns) from the optical signal on the VP connection, thereby detecting the downstream from the optical signal on the VP connection. The optical signal is separated and output to the optical receiver 16.
When receiving the downstream optical signal from the wavelength demultiplexing unit 15, the optical receiving unit 16 of the PON repeater 8 converts the optical signal into an electrical signal.

When the optical receiver 16 converts the downstream optical signal into an electrical signal, the PON protocol termination unit 17 of the PON relay device 8 performs termination of the PON protocol for the electrical signal.
Then, the PON protocol termination unit 17 determines whether or not a signal transmission request is included in the ATM cell which is the electrical signal. If the signal transmission request is included, the PON protocol termination unit 17 stores the signal transmission request in the waiting buffer unit 14. The electrical signal is output to the optical transmitter 18.

When receiving the electrical signal from the PON protocol termination unit 17, the optical transmission unit 18 of the PON relay device 8 converts the electrical signal into an optical signal and outputs the optical signal to the wavelength demultiplexing unit 15.
When receiving the optical signal from the optical transmission unit 18, the wavelength demultiplexing unit 15 of the PON repeater 8 transmits the optical signal to the OLT 4 through the VP connection. That is, the wavelength demultiplexing unit 15 modulates the wavelength of the optical signal to 1.3 microns, for example, and multiplexes the optical signal with the optical signal on the VP connection.
When the OLT 4 receives the optical signal from the PON repeater 8, the OLT 4 converts the optical signal into an electrical signal, and transmits the ATM cell, which is the electrical signal, to the upper network side.
Here, the OLT 4 transmits the electrical signal to the higher network side, but the optical signal may be transmitted to the higher network side without converting the optical signal into the electrical signal.

Next, when the OLT 4 receives, for example, an ATM cell addressed to the ONU 1-1 from the upper network side, the OLT 4 converts the ATM cell, which is an electrical signal, into an optical signal (hereinafter referred to as a downstream optical signal), and transmits the downstream cell through the VP connection. An optical signal is transmitted to the PON relay device 8. That is, the OLT 4 modulates the wavelength of the downstream optical signal to 1.5 microns, for example, and multiplexes the downstream optical signal with the optical signal on the VP connection.
Here, the OLT 4 receives an ATM cell, which is an electrical signal, from the higher network side, but may receive an optical signal from the higher network side.
Further, for convenience of explanation, an ATM cell addressed to the ONU 1-1 is received from the upper network side. However, if the ONU is accommodated in the PON relay device 8, the ONUs 1-2 to 1 other than the ONU 1-1 are used. Even when an ATM cell destined for -N is received, the processing contents shown below are the same.

The wavelength demultiplexing unit 15 of the PON repeater 8 detects the wavelength of the downstream optical signal (for example, a wavelength of 1.5 microns) from the optical signal on the VP connection, thereby detecting the downstream from the optical signal on the VP connection. The optical signal is separated and output to the optical receiver 16.
When receiving the downstream optical signal from the wavelength demultiplexing unit 15, the optical receiving unit 16 of the PON repeater 8 converts the optical signal into an electrical signal.

When the optical receiver 16 converts the downstream optical signal into an electrical signal, the PON protocol termination unit 17 of the PON relay device 8 performs termination of the PON protocol for the electrical signal.
Then, the PON protocol terminator 17 determines whether or not a signal transmission request is included in the ATM cell that is the electrical signal. If the signal transmission request is not included, the PON protocol terminator 17 13 is output.
Since this electric signal is an ATM cell addressed to the ONU 1-1, a signal transmission request is not included.

When receiving the electrical signal from the PON protocol termination unit 17, the PON protocol termination unit 13 of the PON relay device 8 refers to the VPI (Virtual Path Identifier) in the header of the ATM cell that is the electrical signal, and The destination (ONU 1-1 in this example) is identified, and the VC connection corresponding to the destination of the ATM cell is specified.
Then, the PON protocol termination unit 13 outputs the electrical signal to the optical transmission unit 19 and notifies the wavelength demultiplexing unit 11 of the VC connection corresponding to the ATM cell destination.

When receiving the electrical signal from the PON protocol termination unit 13, the optical transmission unit 19 of the PON relay device 8 converts the electrical signal into an optical signal and outputs the optical signal to the wavelength multiplexing / demultiplexing unit 11.
When receiving the optical signal from the optical transmission unit 19, the wavelength demultiplexing unit 11 of the PON relay device 8 transmits the optical signal to the ONUs 1-1 to 1-N through the VC connection notified from the PON protocol termination unit 13. . That is, the wavelength demultiplexing unit 11 modulates the wavelength of the optical signal to, for example, 1.5 microns, and multiplexes the optical signal with the optical signal on the VC connection.

When the ONU 1-1 to 1-N transmit the optical signal through the VC connection assigned to the ONU 1-1 to 1-N by the PON relay apparatus 8 performing the optical signal transmission process as described above. The optical signal is received and converted into an electrical signal, and the ATM cell that is the electrical signal is analyzed.
When the optical signal is transmitted through a VC connection not assigned to itself, the optical signal is discarded without being received.
In this example, the ONU 1-1 receives the optical signal, but the ONUs 1-2 to 1-N do not receive the optical signal.

As apparent from the above, according to the first embodiment, when an optical signal is received from an arbitrary ONU through a VC connection, the optical signal is converted into an electrical signal and stored in the waiting buffer unit 14, and the OLT 4 When the signal transmission request is received through the VP connection, the electrical signal stored in the waiting buffer unit 14 is converted into an optical signal, and the optical signal is transmitted to the OLT 4 through the VP connection. There is an effect that can increase the number of accommodation.
That is, as shown in FIG. 1, if not only the ONUs 3-1 to 3-2 but also the PON relay device 8 is connected to the optical branching coupler 7, the PON relay device 8 becomes the ONU 1-1 to 1-N. Can be accommodated (the PON relay device 8 can accommodate a maximum of 32 ONUs), so that the number of branches of the optical branching coupler 7 is substantially increased to a maximum of 61 (= 31 + 32), The number of ONUs accommodated in the OLT 4 is increased.

  Further, according to the first embodiment, the PON protocol termination unit 13 or the PON protocol termination unit 17 of the PON relay device 8 is configured to convert an optical signal into an electrical signal and terminate the electrical signal once. Even when the transmission distance from the OLT 4 to the ONUs 1-1 to 1-N exceeds 20 km, the transmission distance from the OLT 4 to the PON relay device 8 does not exceed 20 km, and from the PON relay device 8 to the ONUs 1-1 to 1-N. If the transmission distance does not exceed 20 km, the OLT 4 and the ONUs 1-1 to 1-N can transmit and receive optical signals. As a result, the ONU 4 can transmit and receive optical signals to and from the OLTs 1-1 to 1-N. There is an effect that can expand the range.

Embodiment 2. FIG.
4 is a block diagram showing a PON relay device 8 according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG.
When the electrical signal obtained by converting the optical signals transmitted from the ONUs 1-1 to 1-N is stored in the queuing buffer unit 14, the priority processing unit 20 has electrical signals related to the ONUs 1-1 to 1-N having high priority. , The priority order of the ONUs 1-1 to 1-N is notified to the PON protocol termination unit 17 in order.
The priority processing unit 20 constitutes a transmission unit.

In the first embodiment, when the PON protocol termination unit 17 of the PON relay device 8 includes a signal transmission request in the ATM cell transmitted from the OLT 4, the electrical signal stored in the waiting buffer unit 14 is optically transmitted. Although what is output to the transmission unit 18 has been described, that is, the electrical signal stored in the queuing buffer unit 14 is output to the optical transmission unit 18 and transmitted to the OLT 4 without considering the priority of the electrical signals stored in the waiting buffer unit 14. In the second embodiment, the electrical signals related to the ONU having a high priority are sequentially output to the optical transmission unit 18 and transmitted to the OLT 4.
Specifically, it is as follows.

First, the optical signal converted from the optical signal is transmitted to the queuing buffer unit 14 of the PON relay device 8 by transmitting the optical signal from the ONUs 1-1 to 1-N, as in the first embodiment. Is stored.
However, when the PON protocol termination unit 13 stores an electrical signal in the queuing buffer unit 14, the transmission source of the ATM cell is identified by referring to the VPI in the header of the ATM cell that is the electrical signal, for example, transmission Store electrical signals by source.

The priority processing unit 20 of the PON relay device 8 stores, for example, a table in which the priority order of the ONUs 1-1 to 1-N is defined, and refers to the table to determine the priority order of the ONUs 1-1 to 1-N. To the PON protocol termination unit 17.
When the ATM cell transmitted from the OLT 4 includes a signal transmission request, the PON protocol termination unit 17 of the PON relay device 8 performs the electrical signal stored in the waiting buffer unit 14 as in the first embodiment. Are output to the optical transmission unit 18 at that time, taking into account the priority order of the ONUs 1-1 to 1-N notified from the priority processing unit 20, and sequentially extracting from the electrical signals related to the ONUs having a high priority. Output to the transmitter 18.
Thereby, even when the optical signal transmitted from the ONU having the lower priority is stored in the waiting buffer unit 14 first, the optical signal transmitted from the ONU having the higher priority is transmitted to the OLT 4 first. Become.

  As is apparent from the above, according to the second embodiment, when the electrical signals related to the ONUs 1-1 to 1-N are stored in the queuing buffer unit 14, the electrical signals related to the ONUs having the highest priority are ordered. Since the optical signal is converted into an optical signal and transmitted to the OLT 4, an ONU ATM cell having a high priority can be preferentially transmitted.

Embodiment 3 FIG.
5 is a block diagram showing a PON relay device 8 according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG.
When the PON protocol termination unit 13 stores the electrical signal in the queuing buffer unit 14 when the bandwidth monitoring control unit 21 stores the electrical signal in the ATM cell, the bandwidth monitoring control unit 21 exceeds the data allocation amount for the transmission source ONU. The excess of the ATM cell is discarded.
The band monitoring control unit 21 constitutes a receiving unit.

In the first and second embodiments, when the PON protocol termination unit 13 of the PON relay device 8 receives an electrical signal from the optical receiving unit 12, the electrical signal is waited regardless of the data amount of the ATM cell that is the electrical signal. Although what is stored in the buffer unit 14 has been described, in the third embodiment, when the data amount of the ATM cell, which is the electrical signal, exceeds the data allocation amount for the ONU of the transmission source, the ATM cell is exceeded. The amount of data allocated is discarded and stored in the waiting buffer unit 14.
Specifically, it is as follows.

First, it is assumed that the bandwidth monitoring controller 21 of the PON relay device 8 has previously set a data allocation amount for the ONUs 1-1 to 1-N, that is, an allocation bandwidth for the ONUs 1-1 to 1-N.
For example, when the data allocation amount is equally allocated to the ONUs 1-1 to 1-N, if the total bandwidth is “128” and the number of ONUs is 32, each ONU has “4”. Is allocated as a data allocation amount.

For example, when the optical reception unit 12 converts the optical signal transmitted from the ONU 1-1 into an electrical signal and the PON protocol termination unit 13 outputs the electrical signal, the bandwidth monitoring control unit 21 of the PON relay device 8 outputs the electrical signal. The data amount of the ATM cell as a signal is compared with the data allocation amount for the ONU 1-1.
If the data amount of the ATM cell, which is the electrical signal, is less than the data allocation amount for the ONU 1-1, the bandwidth monitoring control unit 21 stores all the electrical signals in the waiting buffer unit 14.
However, if the data amount of the ATM cell as the electrical signal exceeds the data allocation amount for the ONU 1-1, the excess of the ATM cell is discarded (for example, the data in the latter half of the ATM cell is discarded). Only the data allocation amount is stored in the waiting buffer unit 14.

  As is apparent from the above, according to the third embodiment, when an optical signal is converted into an electrical signal and stored in the queuing buffer unit 14, the data amount of the electrical signal is equal to the data allocation amount for the transmission source ONU. When it exceeds, since it was comprised so that the excess of the electrical signal might be discarded, there exists an effect which can maintain the fairness of ONU1-1-1-N accommodated in the PON relay apparatus 8.

In the third embodiment, the bandwidth monitoring control unit 21 is set with individual data allocation amounts for the ONUs 1-1 to 1-N. When the data allocation amount is set and the bandwidth monitoring control unit 21 exceeds the data allocation amount for the entire ONUs 1-1 to 1-N when the data amount of the electrical signal transmitted from an arbitrary ONU is exceeded, The excess may be discarded.
In this case, there is an effect that it is possible to eliminate the data transmission exceeding the PON system allows and avoid the congestion of the PON system.

It is a block diagram which shows the PON system by Embodiment 1 of this invention. It is a block diagram which shows the PON relay apparatus by Embodiment 1 of this invention. It is explanatory drawing which shows the logical connection relationship of ONU and OLT with respect to a PON relay apparatus. It is a block diagram which shows the PON relay apparatus by Embodiment 2 of this invention. It is a block diagram which shows the PON relay apparatus by Embodiment 3 of this invention.

Explanation of symbols

  1-1 to 1-N, 2-1 to 2-N, 3-1 to 3-2 ONU (network terminator), 4 OLT (station side device), 5, 6, 7 Optical branching coupler, 8 PON Repeater, 11 Wavelength demultiplexing unit (reception unit, transfer unit, first wavelength demultiplexing unit), 12 Optical receiving unit (receiving unit, first optical receiving unit), 13 PON protocol termination unit (receiving unit, transfer) Means, first protocol termination unit), 14 waiting buffer unit, 15 wavelength demultiplexing unit (transmission unit, transfer unit, second wavelength demultiplexing unit), 16 optical receiving unit (transmission unit, transfer unit, second Optical receiver), 17 PON protocol termination unit (transmission means, transfer means, second protocol termination unit), 18 optical transmission unit (transmission means, second optical transmission unit), 19 optical transmission unit (transfer means, first transmission unit) 1 optical transmission unit), 20 priority processing unit (transmission means), 21 bands Monitor control section (receiving means).

Claims (11)

  A receiving unit which is connected to a plurality of network termination devices via a VC connection and receives an optical signal from an arbitrary network termination device through a VC connection; When a signal transmission request is received from the station side device through the VP connection, the electrical signal stored in the buffer is converted into an optical signal, and the optical signal is converted to the station side through the VP connection. A PON relay device comprising transmission means for transmitting to the device.   When the optical signal is received from the station side device through the VP connection, the optical signal is terminated to identify the destination network termination device, and the optical signal is transferred to the destination network termination through the VC connection corresponding to the network termination device. 2. The PON relay apparatus according to claim 1, further comprising transfer means for transferring to the apparatus.   When the electrical signals related to a plurality of network termination devices are stored in the buffer, the transmission means converts the electrical signals related to the network termination devices with higher priority in order to optical signals and transmits them to the station side device. The PON relay device according to claim 1, wherein the PON relay device is characterized.   When the receiving means converts the optical signal into an electric signal and stores it in the buffer, if the data amount of the electric signal exceeds the data allocation amount for the network terminating device of the transmission source, the excess of the electric signal is calculated. The PON relay device according to any one of claims 1 to 3, wherein the PON relay device is discarded.   A plurality of network termination devices that transmit optical signals, a station-side device that transmits a signal transmission request when collecting optical signals transmitted from the plurality of network termination devices, and an arbitrary one of the plurality of network termination devices When an optical signal is received from a network terminating device through a VC connection, the optical signal is converted into an electrical signal and stored in a buffer, and when a signal transmission request is received from the station side device through a VP connection, it is stored in the buffer. A PON system comprising: a PON relay device that converts an electrical signal that has been converted into an optical signal and transmits the optical signal to the station side device through a VP connection.   When the PON repeater receives the optical signal from the station side device through the VP connection, the PON repeater terminates the optical signal, identifies the destination network termination device, and transmits the optical signal through the VC connection corresponding to the network termination device. 6. The PON system according to claim 5, wherein the PON system is transferred to a destination network termination device.   When the PON repeater stores the electrical signals related to a plurality of network termination devices in the buffer, the PON relay device converts the electrical signals related to the network termination devices with higher priority in order to optical signals and transmits them to the station side device. The PON system according to claim 5 or 6, characterized by the above.   When the PON relay device converts an optical signal into an electrical signal and stores it in the buffer, if the data amount of the electrical signal exceeds the data allocation amount for the network terminating device of the transmission source, the excess of the electrical signal The PON system according to claim 5, wherein the PON system is discarded.   A first optical receiver that converts an optical signal of a predetermined wavelength into an electrical signal, a first optical transmitter that converts an electrical signal into an optical signal of a predetermined wavelength, and an optical signal received from a VC connection; A first wavelength multiplex that separates an optical signal having a wavelength and outputs the separated optical signal to the first optical receiver, while multiplexing and outputting the optical signal having a predetermined wavelength from the first optical transmitter. The separation unit, the first protocol termination unit for terminating the electrical signal processed by the first optical reception unit and the first optical transmission unit, and the termination processed by the first protocol termination unit A buffer unit that stores the electrical signal, a second optical receiver that converts an optical signal of a predetermined wavelength into an electrical signal, a second optical transmitter that converts an electrical signal into an optical signal of a predetermined wavelength, When an optical signal is received from the VP connection, light of a predetermined wavelength A second wavelength demultiplexing unit that multiplexes and outputs the optical signal to the VP connection upon receiving an optical signal of a predetermined wavelength from the second optical transmission unit. A second protocol termination unit for terminating an electrical signal processed by the second optical reception unit and the second optical transmission unit, and the second wavelength demultiplexing unit is optically connected from the VP connection. When the signal is received, the second optical receiving unit and the first optical transmitting unit convert the signal and output the VC connection from the first wavelength demultiplexing unit. The second wavelength demultiplexing unit When a signal transmission request is included in the received optical signal, the second optical transmission unit converts the electrical signal stored in the buffer unit into an optical signal, and the second wavelength multiplexing / demultiplexing unit PON relay output to VP connection Location.   A priority processing unit for determining a transmission priority of the electrical signal stored in the buffer unit, and the second optical transmission unit converts the electrical signal stored in the buffer unit into an optical signal according to the transmission priority The PON repeater according to claim 9, wherein the optical signal is output from the second wavelength demultiplexing unit.   A bandwidth monitoring control unit that compares the data amount of the electrical signal terminated at the first protocol termination unit with the data allocation amount, and if the data amount of the electrical signal exceeds the data allocation amount, The PON relay device according to claim 9 or 10, wherein the monitoring control unit discards the excess.

Images