JP3589079B2 - Transmission quality measuring method and apparatus in ATM optical access network - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for measuring transmission quality in an ATM optical access network (PON).
[0002]
[Prior art]
One form of the optical access network is a PON (Passive Optical Network) method. In the PON system, since an access network is constructed only by optical passive elements such as an optical coupler between an OLT (Optical Line Terminal) on the station side and an ONU (Optical Network Unit) on the subscriber side, a passive optical system is used. Called network. This PON system has the same basic configuration as a PDS (Passive Double Star) system, but can access point-to-multipoint between a station and a plurality of subscribers. Realize contributing subscriber multiplexing.
FIG. 5 shows an ATM-PON communication system in which a subscriber unit 52 is branched and connected to an optical line terminal 51 via an optical transmission line 53 and transmits cells forming a frame in an ATM (asynchronous transfer mode). I have. In this ATM-PON communication system, there is a transmission quality test for measuring the transmission quality between the optical line terminal 51 and a plurality of (MAX32 branch) subscriber side devices 52. Here, the transmission quality test is a test performed for all connections supported between the optical line terminal 51 and the subscriber side device 52.
As shown in FIG. 6, in the ATM-PON communication system, since a plurality of subscriber devices 52 are connected, N types of support connections per subscriber device and M types of optical branching (M ≦ 32, N > M), the test device 54 of the optical line terminal 51 performs a transmission quality test for (N × M) types of connections, and the test device 55 of the subscriber side device 52 performs N types of connections. , A transmission quality test will be performed. In this transmission quality test, an OAM (Operation Administration and Maintance) function for a connection is performed by adding overhead information (OAM cell 57) to each of the user cells (the test target user cell 56 and the non-test target user cell 58). Is achieved.
[0003]
[Problems to be solved by the invention]
According to the above-described conventional example, when the number of support connections increases by one, the scale of the memory used for the transmission quality test of the station side device 51 and the subscriber side device 52 increases, and furthermore, the peripheral hardware There was a drawback that the size of the wear also increased.
On the other hand, under the condition that only the transmission quality test for the total bandwidth of the connection supported between the optical line terminal 51 and the subscriber device 52 is supported, the connection of the transmission quality test performed by the optical line terminal 51 is Although there are (N × M) types of connections, this is equivalent to performing a transmission quality test for each subscriber device (M types). Although there are N types of connections in the transmission quality test performed by the subscriber side device, this is equivalent to performing the transmission quality test collectively (one type) on the input connections.
The present invention has been made in view of the above circumstances, and is provided on the condition that an ATM-PON communication system supports only a transmission quality test related to a total bandwidth of a connection supported between a station apparatus and a subscriber apparatus. The station-side device performs a transmission quality test for each connection output to the subscriber-side device and the subscriber-side device for all input cells. It is an object of the present invention to provide a transmission quality measuring method and apparatus in an ATM optical access network which can reduce the hardware scale of a transmission quality test of a user side device.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a transmission quality measuring method in an ATM optical access network according to the first aspect of the present invention provides a point-to-point communication between a station and a plurality of subscribers via an optical transmission line by band allocation control using ATM cells. In an ATM optical access network accessed by two-to-multipoint, on condition that only a transmission quality test concerning the total bandwidth of the connection supported between the station side device and the subscriber side device is performed, the station side device and each subscriber side A transmission quality test is performed for each of the input cells in the subscriber side device for each connection with the device . According to a second aspect of the present invention, there is provided a transmission quality measuring method for use in an ATM optical access network, wherein the transmission quality test performed by the station side apparatus receives a cell. Based on the extracted subscriber information, reads transmission quality test information from a built-in memory based on the extracted subscriber information, and performs a transmission quality test on the reception cell based on the transmission quality test information. And Further, in the transmission quality measuring method in the ATM optical access network according to the third aspect, in the transmission quality measuring method according to the first aspect, the transmission quality test performed in the subscriber unit receives a cell and sets the received cell as a received cell. The transmission quality test information is read from a built-in memory based on the transmission quality test information, and a transmission quality test of the reception cell is performed.
[0005]
A transmission quality measuring device in an ATM optical access network according to claim 4, wherein a station and a plurality of subscribers are connected via an optical transmission line, and N types of support connections per subscriber unit are provided, and the number of optical branches. Is an M type ATM optical access network, a test apparatus in the station side apparatus, which performs a transmission quality test, receives as input an N × M connection cell and outputs the M type subscriber information. A cell information extraction unit for extracting one of the cells and outputting an N × M connection cell; and reading transmission quality information from an insertion processing memory based on subscriber unit information obtained from the cell information extraction unit. A transmission quality insertion processing unit for performing a transmission quality test process on a cell, wherein the test device for testing the transmission quality in the subscriber unit receives the N connection cells as an input. A transmission quality extraction processing unit that reads information for performing a transmission quality test from a built-in extraction processing memory, performs a transmission quality test on the cell, and outputs an N connection cell.
[0006]
The present invention is based on the condition that the system supports only the transmission quality test for the total bandwidth of the connection supported between the station side device and the subscriber side device. Although there are (N × M) types of connections, it is equivalent to performing a transmission quality test for each subscriber device (M types), and the connection of the transmission quality test performed by the subscriber test device is Focusing on the fact that although there are N types, the transmission quality test is equivalent to performing a transmission quality test collectively (one type) on the input connections, and performing a transmission quality test for each M types of subscriber units in the station side device. By performing a transmission quality test on the N types of input connections collectively in the subscriber unit, the type of data to be stored in the memory is changed from (N × M) types to M, The type of memory storage information required can be reduced to one type, and peripheral hardware can be reduced.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 and 2 are block diagrams showing an embodiment of the present invention, in which a test device (hereinafter, referred to as a station test device 4) of a station device and a test device (hereinafter, a subscription device) of a subscriber device, respectively. 2 shows the internal configuration of the tester 5).
In FIG. 1, the station test apparatus 4 includes a station-side cell information extraction unit 9, a transmission quality insertion processing unit 10, and an insertion processing memory 11. In FIG. 2, the subscriber test apparatus 5 includes a transmission quality extraction processing unit 12 and an extraction processing memory 13.
[0008]
The station-side cell information extraction unit 9 receives the cells of the (N × M) connection, extracts one of the M types of subscriber unit information, and outputs the cells of the (N × M) connection. The transmission quality insertion processing unit 10 reads transmission quality test information from the insertion processing memory 11 based on the M types of subscriber device information output from the station-side cell information extraction unit 9, and based on the management information, The transmission quality test processing is performed on the cell, and the cell of the (N × M) connection is output.
The transmission quality extraction processing unit 12 receives N connection cells, reads information for performing a transmission quality test from the extraction processing memory 13, and performs a transmission quality test process on the input cells based on the management information. .
[0009]
3 and 4 are diagrams cited for explaining the operation of the embodiment of the present invention. The flowchart of the procedure of the transmission quality test process after the cell is received by the station test device 4 and the subscriber test device 5, respectively. Indicated by
Prior to the description of the operation, if a system that supports only the transmission quality test related to the total bandwidth of the connection supported between the optical line terminal and the subscriber unit is used, the connection of the transmission quality test performed by the Is an (N × M) type connection, which is equivalent to performing a transmission quality test on a subscriber unit basis (M type). Although there are N types of connections, as described above, this is equivalent to performing a transmission quality test collectively (one type) of input connections.
[0010]
The present invention utilizes this fact, and the operation of the embodiment of the present invention shown in FIGS. 1 and 2 will be described below with reference to the flowcharts shown in FIGS.
First, when a cell is received by the station-side cell information extraction unit 9 of the station test apparatus 4 (step A1), subscriber unit information is extracted from the received cell (step A2), and the extracted information is transmitted to the transmission quality insertion processing unit 10 Is output simultaneously with the input cell (step A3). The transmission quality insertion processing unit 10 reads the transmission quality test information from the insertion processing memory 11 based on the subscriber device information (step A4), performs transmission quality processing on the cell, and outputs the cell (step A4). A5).
[0011]
When the transmission quality extraction processing section 12 of the subscriber test apparatus 5 receives a cell (step B1), the transmission quality test information is extracted from the extraction processing memory 13 (step B2). The transmission quality extraction processing unit 12 performs a transmission quality test process on the cell based on the extracted transmission quality test information, and outputs the cell (step B3).
Note that the transmission quality test processing itself by the transmission quality insertion processing unit 10 and the transmission quality extraction processing unit 12 is an operation equivalent to the conventional transmission quality test processing.
[0012]
As described above, according to the present invention, on the condition that only the transmission quality test for the total bandwidth of the connection supported between the optical line terminal and the subscriber side device is supported, the optical line terminal outputs to the subscriber device. For each connection, the subscriber unit performs a transmission quality test on all input cells to reduce the hardware scale of the transmission quality test of the optical line terminal and the hardware scale of the transmission quality test of the subscriber unit. It is.
[0013]
【The invention's effect】
As described above, according to the present invention, the memory can be reduced and the peripheral hardware scale can be reduced. That is, by performing a transmission quality test for each of the M types of subscriber units in the station-side device, the types of data to be stored in the memory can be reduced from (N × M) types to M types, and In, by performing a transmission quality test collectively on N types of input connections, N types of required memory storage information can be reduced to one type.
In addition, an increase in memory capacity when the number of support connections increases can be suppressed. The reason is that the transmission quality test is performed for each subscriber unit in the optical line terminal, so that even if the number of supported connections increases, the connection becomes unrelated to the memory, and the number of connections increases in the subscriber side device. This is because the transmission quality test is performed together with the increased connections.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a block diagram showing an embodiment of the present invention.
FIG. 3 is a flowchart cited for explaining the operation of the embodiment shown in FIG. 1;
FIG. 4 is a flowchart cited for explaining the operation of the embodiment shown in FIG. 2;
FIG. 5 is a block diagram showing a connection configuration of an ATM-PON communication system.
FIG. 6 is a diagram showing an operation concept in conventional transmission quality measurement.
[Explanation of symbols]
4 station test apparatus, 5 subscriber unit, 9 station cell information extraction unit, 10 transmission quality insertion processing unit, 11 insertion processing memory, 12 transmission quality extraction processing unit, 13 extraction processing memory

Claims (4)

In an ATM optical access network in which a station and a plurality of subscribers are accessed point-to-multipoint via an optical transmission line by band allocation control using ATM cells, support is provided between the station side device and the subscriber side device. A transmission quality test is performed on all input cells at the subscriber unit for each connection between the optical line terminal and each subscriber unit , provided that only a transmission quality test on the total bandwidth of the connection is performed. A method for measuring transmission quality in an ATM optical access network. The transmission quality test performed by the station side device receives a cell, extracts subscriber unit information based on the received cell, reads transmission quality test information from a built-in memory based on the extracted subscriber information, 2. The transmission quality measuring method in an ATM optical access network according to claim 1, wherein a transmission quality test of the received cell is performed based on the transmission quality test information. The transmission quality test performed by the subscriber unit receives a cell, reads transmission quality test information from a built-in memory based on the received cell, and performs a transmission quality test on the received cell. 2. A method for measuring transmission quality in an ATM optical access network according to item 1. In an ATM optical access network in which a station and a plurality of subscribers are connected via an optical transmission line and the number of support connections per subscriber device is N and the number of optical branches is M, the station side device has A test apparatus that performs a transmission quality test receives a cell of an N × M connection as an input, extracts one of M types of subscriber information, and outputs a cell of an N × M connection. An information extraction unit, and a transmission quality insertion processing unit that reads transmission quality information from an insertion processing memory based on subscriber unit information obtained from the cell information extraction unit and performs a transmission quality test process on the cell. A test apparatus in the subscriber side apparatus for performing a transmission quality test receives an N connection cell as an input and reads out information for performing a transmission quality test from a built-in extraction processing memory. And a transmission quality extracting unit for performing a transmission quality test on the cell and outputting an N connection cell.

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