KR100227342B1 - Atm optical switching system - Google Patents

Abstract

More particularly, the present invention relates to an ATM optical switching system, and more particularly, to a method and system for improving ATM cell processing efficiency when ATM cells are exchanged at high speed by collectively processing a plurality of ATM cells exchanged in an ATM optical switching system And the like.

In the conventional ATM optical switching system, tuning is difficult because the operation speed of an optical device is limited when an ATM cell is input in a short period of several microseconds or less, and tuning for generating a specific optical wavelength for each ATM cell within the arrival period of the ATM cell There is a problem that the burden becomes large.

The present invention stores an ATM cell input from an ATM optical bridge and stores a predetermined number of ATM cells in a buffer and processes the ATM cells in a batch so as to reduce the tuning burden of controlling wavelengths in optical signal processing The ATM cell can be exchanged at a high speed and the overall ATM cell processing efficiency can be improved.

Description

ATM broadband ventilation

More particularly, the present invention relates to an ATM optical switching system, and more particularly, to a method and system for improving ATM cell processing efficiency when ATM cells are exchanged at high speed by collectively processing a plurality of ATM cells exchanged in an ATM optical switching system And the like.

Generally, in ATM (Asynchronous Transfer Mode) exchanges, when processing input ATM cells, each ATM cell is processed as 53 bytes of data consisting of a 5-byte header and a 48-byte payload. The speed of the standard ATM interface is 155 Bbit / s and 622 Bbit / s or 2.4 Gbit / s. Therefore, ATM exchanges perform ATM cell exchange at high speed through hardware without complicated processes such as error control and flow control. Recently, optical ATM networks have been developed and optical ATM networks have been developed. I am using it.

As shown in FIG. 1, the conventional ATM optical switching unit includes an optical / electrical signal converting unit 30, a optical switching unit 10, and a control unit 20. The optical / (30) converts ATM cells inputted as optical signals through input ports (I1 - I4) into electrical signals for transmission. The control unit 20 analyzes the output port information included in the header of the ATM cell transmitted from the optical / electrical signal converter 30 and then checks the output ports O1 to O4 to which the corresponding ATM cell is output, And transmits a control signal. The optical switching unit 10 switches according to a control signal transmitted from the control unit 20 and outputs the corresponding ATM cell through corresponding output ports O1 to O4.

The operation of the conventional ATM optical bridge circuit constructed as described above will be described below.

For example, by analyzing the header portion of the ATM cell, an ATM cell having information on the third output port O3 is input to the first input port I1 and information on the second output port O2 The ATM cell having the information on the first output port O1 is input to the third input port I3 and the ATM cell having the information on the first output port O1 is input to the second input port I2, ATM cells input to the input ports I1 through I4 are input to the optical / electrical signal corresponding to the optical / electrical signal change unit 30, And converted into electric signals by the signal converters 31 to 34.

At this time, the control unit 20 analyzes the output port information included in the header part of the ATM cell converted into the electric signal, so that the output ports O1 to O4 to which the corresponding ATM cell is output can be checked. The ATM cell input to the second input port I2 is transferred to the second output port O2 via the optical signal having the wavelength of ' Since the ATM cell input to the third input port I3 must be output to the first output port O1, the light having the wavelength of 'W1' And the ATM cell input to the fourth input port I4 is to be output to the fourth output port O4, so that the ATM cell having the optical wavelength of 'W4' is transmitted.

Therefore, the optical switching unit 10 multiplexes the optical signals of 'W3, W2, W1 and W4' transmitted from each optical / electrical signal converting unit 30 and transmits them, and the output ports O1 to O4 are multiplexed And detects and outputs only the optical signal of the wavelength corresponding to the port of the optical signal to be transmitted. That is, the first output port O1 detects only the optical signal of 'W1', the second output port O2 detects only the optical signal of 'W2', and the third output port O3 detects the optical signal of 'W3' Only the optical signal is detected, and the fourth output port O4 detects only the optical signal of 'W4'.

Meanwhile, in the conventional ATM optical bridging apparatus operating as described above, when an optical signal for optical exchange is generated for an ATM cell input to any one input port, for example, the input signal is input to the first input port I1 , It is assumed that ATM cells input to the first input port I1 are connected to the output ports 'O2, O3, O2, O4 and O1', respectively, as shown in FIG. The controller 20 converts the output port information included in the header of the inputted ATM cell into an output signal of the first optical / electrical signal converter 31 of the optical / electric signal converter 30, W2, W3, W2, W4, and W4 of wavelengths corresponding to different wavelengths, that is, the identified output ports, so as to receive the corresponding ATM cells from the output ports after confirming the output ports O1 to O4 to be output, W1 '.

Therefore, in the conventional art, when the ATM cells input to any one input port have information on different output ports in the header portion, optical signals having different wavelengths must be generated for each arrival period of the ATM cells.

However, in the conventional ATM optical switching system, when the arrival period of the ATM cell input to one input port is less than 1 microsecond, there is a problem in that tuning is difficult because the operation speed of the optical device is limited. In the case where the ATM cell is short In case of inputting a periodic signal, an optical signal for an inputted ATM cell is converted into an electric signal, and then an optical signal corresponding to an output port is generated and output. In the short period of time which is several microseconds or less, There is a problem that the tuning burden of generating a specific light wavelength for the cell becomes large.

SUMMARY OF THE INVENTION The present invention has been conceived in view of the above problems, and it is an object of the present invention to provide an ATM optical switching system in which a predetermined number of ATM cells outputted from the same output port are grouped into one super cell, It is possible to reduce the tuning burden due to the generation of the ATM cells and to exchange the ATM cells at a high speed, thereby improving the overall processing efficiency.

According to an aspect of the present invention, there is provided an ATM bridging system comprising: an ATM bridging unit for analyzing an ATM cell input through each input port and grouping a predetermined number of ATM cells into a plurality of output cells, A plurality of ATM cell processing units for transmitting the optical signals on optical signals of predetermined wavelengths corresponding to the plurality of ATM cells; An optical signal multiplexing unit multiplexing and transmitting optical signals of different predetermined wavelengths transmitted from the respective ATM cell processing units; And a tuner unit which detects only optical signals corresponding to the respective output ports out of the multiplexed optical signals transmitted from the optical signal multiplexer and outputs the optical signals through corresponding output ports.

Each ATM cell processing apparatus includes a buffer unit having a buffer corresponding to each output port and storing an ATM cell for each output port; An input port processing unit which converts an ATM cell input to an input port into an optical signal and converts the ATM cell into an electric signal and is transmitted to a corresponding buffer of the buffer unit according to output port information included in a header part of the converted ATM cell; Further comprising an optical signal transmission unit for combining the predetermined number of ATM cells stored in the respective buffers of the buffer unit to generate a super cell and then transmitting the super cell on an optical signal of a predetermined wavelength corresponding to an output port to which the corresponding super cell is to be output .

FIG. 1 is a block diagram of a conventional ATM optical bridge. FIG.

FIG. 2 is an example of processing of an ATM cell in the ATM optical bridge shown in FIG. 1; FIG.

FIG. 3 is a block diagram of a configuration of an ATM optical bridge according to the present invention; FIG.

FIG. 4 is an exemplary view showing the processing of an ATM cell in the ATM optical bridge shown in FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

10: optical bridge 20:

30: Optical / electrical signal conversion unit 40 to 70: ATM cell processing unit

80: Optical signal multiplexing unit 90: Tuner unit

I1 ~ I4: Input port O1 ~ O4: Output port

IPP1 to IPP4: input port processing units BUF1 to BUF4: buffer unit

SEL1 to SEL4: Optical signal transmission units 91 to 94: Tuner

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

There are a plurality of input and output ports of a general ATM optical bridging. In the embodiment of the present invention, however, four input and output ports are provided for convenience of description, and the number of ATM cells to be processed at one time is two.

The ATM optical bridging apparatus according to the present invention comprises a plurality of ATM cell processing units 40 to 70, an optical signal multiplexing unit 80 and a tuner unit 90 as shown in FIG. 3 .

Each of the ATM cell processing units 40 to 70 converts an ATM cell input as an optical signal through each of the input ports I1 to I4 into an electrical signal and analyzes the output port information included in the header of the corresponding ATM cell The output ports O1 to O4 to be output by the corresponding ATM cell are checked and stored in the corresponding buffers of the buffer units BUF1 to BUUT4 according to the output ports O1 to O4, The cells are bundled into a super cell and transmitted on an optical signal of a predetermined wavelength corresponding to the output ports O1 to O4.

The optical signal multiplexing unit 80 multiplexes the super macro optical signals transmitted on the different specific optical signals from the ATM cell processing units 40 to 70 and transmits the multiplexed super macro optical signals to the tuner unit 90. The optical signal multiplexing unit 80 Only the optical signals corresponding to the output ports O1 to O4 are detected from the multiplexed supplecell optical signals transmitted from the output ports O1 to O4.

The ATM cell processing units 40 to 70 further include input port processing units IPP1 to IPP4, buffer units BUF1 to BUF4 and optical signal transfer units SEL1 to SEL4. To IPP4 convert the ATM cells inputted into the input ports I1 to I4 into the electric signals in the optical signal state and analyze the output port information included in the header part of the ATM cell to output the output ports O1 to O4 And then transfers the ATM cells to the corresponding buffers of the buffer units BUF1 to BUF4 according to the identified output ports O1 to O4. Each of the buffer units BUF1 to BUF4 includes buffers corresponding to the output ports O1 to O4 to store ATM cells to be output to the output ports O1 to O4. The optical signal transmission units SEL1 to SEL4 combine the two ATM cells stored in the respective buffers of the buffer units BUF1 to BUF4 to generate one super cell and then transmit the corresponding one of the output ports O1 to O4 And transmits the optical signal.

The operation of the present invention configured as described above will be described as follows.

For example, assuming that ATM cells input to the first input port I1 are output to the respective output ports 'O2, O2, O4 and O4' as shown in FIG. 4, The input port processing unit IPP1 of the processing unit 40 converts an ATM cell inputted as an optical signal state through the first input port I1 into an electric signal and outputs the output port information O2 to O4 and outputs the output ports O1 to O4 to the buffer unit BUF1 according to the output ports O1 to O4. When the output port of the input ATM cell is O2, O2, O4 , O4, and O1 ', two ATM cells are stored in the second buffer of the buffer unit BUF1, two ATM cells are stored in the fourth buffer, and one ATM cell is stored in the first buffer.

At this time, the optical signal transmission unit SEl1 searches the first buffer of the buffer unit BUF1 in the round-robin manner for the fourth buffer, and when two or more ATM cells are stored, the optical signal transmission unit SEl1 bundles the stored two ATM cells into super cells The optical signal corresponding to the output ports O1 to O4 to be outputted is transmitted.

Therefore, the optical signal transmitting unit SEl1 searches for the first buffer first, and the first buffer is empty, so that the second buffer is searched next. At this time, the second output port O2 The two ATM cells are grouped into one super cell and the super-cells are added to the optical signal W2 corresponding to the second output port O2, and the optical signal multiplexing unit 80 multiplexes the two ATM cells, Lt; / RTI >

The optical signal multiplexing unit 80 multiplexes the optical signal W2 transmitted from the first ATM cell processing unit 40 and the supple cell optical signals of the other wavelengths transmitted from the remaining three ATM cell processing units 50 through 70 And transmits the multiplexed signal to the tuner unit 90.

Each of the tuners 91 to 94 of the tuner unit 90 receives the multiplexed multicell optical signals and outputs them through the respective output ports O1 to O4. And detects only the supercell optical signal of a specific wavelength corresponding to the output ports (O1 to O4) connected to the optical signal.

Therefore, since the second tuner 92 of the tuner unit 90 detects only the supercell optical signal of '92', the second output port O2 is provided with two ATM The cells are exchanged.

In the same manner, the optical signal transmitting unit SEl1 of the first ATM cell processing device 40 searches the third buffer, and the fourth buffer is searched because there is no ATM cell in the third buffer.

At this time, since two ATM cells are stored in the fourth buffer, the two ATM cells are grouped into one super cell, and a super cell is added to the optical signal W4 corresponding to the fourth output port O4, (80).

The optical signal multiplexing unit 80 multiplexes the optical signal W4 from the ATM cell processing unit 40 and the supple cell optical signals of the other wavelengths transmitted from the remaining three ATM cell processing units 50 to 70 And transmits the multiplexed signal to the tuner unit 90.

Then, each of the tuners 91 to 94 of the tuner unit 90 detects only the supercell optical signal of a specific wavelength corresponding to the output ports (O1 to O4) connected thereto with respect to the multiplexed supercell optical signal, The fourth tuner 94 of the tuner unit 90 detects only the super-cellular optical signal of the 'W4', and thus the two ATM cells are exchanged.

Therefore, by processing a single super cell composed of two ATM cells at once, the unit processing time in the ATM optical interconnection corresponds to twice the arrival period in which one 53-byte ATM cell is input, The number of ATM cells constituting the ATM optical network can be adjusted appropriately according to the performance of the ATM optical switching unit to reduce the tuning burden of adjusting the wavelength in the optical signal transmission unit or adjusting the wavelength of the optical signal to be received in the tuner unit .

As described above, according to the present invention, an ATM cell input from an ATM optical bridge is stored in a buffer, and a predetermined number of stored ATM cells are configured as one super cell and collectively processed to control wavelengths during optical signal processing It is possible to reduce the tuning burden and to exchange ATM cells at high speed, thereby improving the overall ATM cell processing efficiency.

Claims (2)

In ATM optical switching, ATM cells input through respective input ports are analyzed, and a predetermined number of ATM cells are super celled according to the identified output port information, and the ATM cells are transmitted on an optical signal of a predetermined wavelength corresponding to each output port A plurality of ATM cell processing units; An optical signal multiplexing unit multiplexing and transmitting optical signals of different predetermined wavelengths transmitted from the respective ATM cell processing units; And a tuner unit outputting only the optical signals corresponding to the respective output ports out of the multiplexed optical signals transmitted through the optical signal multiplexing unit and outputting the optical signals through corresponding output ports. 2. The apparatus of claim 1, wherein each of the ATM cell processing units comprises: a buffer unit having a buffer corresponding to each output port and storing an ATM cell for each output port; An input port processor for converting an ATM cell input to an input port into an electric signal in an optical signal state and transmitting the electric signal to a corresponding buffer of the buffer unit according to output port information included in a header part of the converted ATM cell; Further comprising an optical signal transmission unit for combining the predetermined number of ATM cells stored in the respective buffers of the buffer unit to generate a super cell and then transmitting the super cell on an optical signal of a predetermined wavelength corresponding to an output port to which the corresponding super cell is to be output Wherein the at least one at least one of the at least two ATM bridges.