KR100233940B1 - Apparatus for connecting subscriber link for atm switch - Google Patents

Abstract

The present invention relates to a subscriber link access device (SALUA) of an asynchronous transfer mode (ATM) switch, wherein an ATM subscriber cell stream using only two cores of an STM-1 optical link is used for a subscriber board performing two-way communication using two cores By enabling bi-directional communication, the present invention provides an economical and simple functional subscriber board that can accommodate multiple subscriber links on a single subscriber board.

Description

Subscriber Link Interface (SALUA) in Asynchronous Transfer Mode (ATM) Exchange

The present invention relates to a subscriber link access device (SALUA) of an asynchronous transmission mode (hereinafter referred to as ATM) switch, which uses two cores of STM-1 optical link to enable two-way communication of an ATM subscriber cell stream. A subscriber link connection (STM-1 ATM link UNI Assembly: hereinafter referred to as SALUA) of a class ATM switch.

In general, subscriber matching devices used in high-capacity ATM exchanges are implemented to receive optical signals transmitted from ATM subscribers (eg, VOD video terminals, multi-generation residential subscribers, business subscribers, etc.) using two optical cores. In addition, the storage unit for storing data received through each line is also a one-to-one correspondence configuration connected one per subscriber.

However, at present, the capacity of this ATM switch is growing exponentially, and two optical cores are connected to each subscriber and data processing boards are connected to each subscriber to perform all the information processing on the ATM subscribers connected to them. If so, the inconvenience that the total size of the exchange becomes very large occurs.

In accordance with the above-described modern trend, the present invention provides an ATM subscriber link connecting device installed in a large capacity ATM switch, which can accommodate multiple subscribers through a single board while having an economical and simple functional structure. The purpose is to implement a connection device.

In order to achieve the above object, in the present invention, the STM-1 class optical link core using two lines for transmitting / receiving for bidirectional communication is referred to as WDM (Wavelength Division Multiplexing). By using a coupler applied), even if only one core is used, bidirectional communication of the ATM subscriber cell stream is achieved.

Here, a schematic description of the SALUA applying the WDM scheme proposed in the present invention describes that the SALUA physically accommodates 16 WDM termination interfaces, and these 16 WDM termination interfaces are bidirectional communication of STM-1 class ATM subscribers. It delivers ATM cell streams.

In addition, the SALUA is applied to each ATM subscriber side input cell stream and the user parameter control (UPC) algorithm applied to the ATM subscriber side through the WDM termination interface, operation, monitoring and maintenance (Operation, Administration and Maintenace: It is called OAM) function to multiplex the cells for inter-processor communication (hereinafter referred to as IPC) on the result of performance and convert them into optical signals and transmit them to the switching module through the optical transmission link. .

In addition, the optical signals received through the optical receiving link from the switching module are demultiplexed into electrical signals, converted into STM-1 frames, to extract / execute OAM information, and to output the ATM gap-side output cell stream to the WDM termination interface.

According to the recent rapid development of communication technology and various service demands, the ATM-based Broadband Telecommunication Network (B-ISDN), which uses the ATM method, is recognized as a high-speed public telecommunication network. The transmission speed, reliability, and the ability to transfer various information are expected to become the main communication networks for high speed data communication in the future.

In addition, due to the development of device technology for optical communication, various optical devices having high speed and high capacity transmission functions are rapidly appearing in the commercial market.

1 is a model diagram showing a connection state between an ATM switch and an ATM subscriber incorporating a subscriber link connection device of the present invention.

2 is a block diagram showing a subscriber link access device (SALUA) of the present invention.

3 is a detailed block diagram of the WDM interface unit of FIG.

4 is a detailed block diagram of the switching module optical transmitter / receiver of FIG.

<Explanation of symbols for main parts of drawing>

100: VOD video terminal 200: residential subscriber

300: work type subscriber 400: PCS-ATM network interworking device

500: large capacity ATM switch 50: subscriber link access device (SALUA)

51: WDM interface function unit 511: coupler

512: photodiode (PD) 513: laser diode (LD)

52: STM-1 class link termination function 53: ATM cell processing function

531: receiving user cell storing means 532: transmitting IPC cell storing means

533: receiving OAM storage means 534: connection information table

54: traffic management function unit 55: STM-1 synchronization unit

56: Optical module for transmitting / receiving switching module 561, 566: Input register

562: Multiplexer 563: Timing Generator

564, 568: output register 565: multiplexer

567 demultiplexer 569 timing and control

600: demultiplexer 57: subscriber board control processing unit

According to the characteristic of the SALUA structure of the present invention to operate as described above, the optical signal of the STM-1 speed transmitted from the ATM subscriber side through the optical link interface, and a plurality of two-way communication through one core optical link A WDM interface function for terminating the two WDM links; An STM-1 class link termination function unit for performing STM-1 class frame generation and termination functions on the optical signal input through the WDM interface function unit; An ATM cell processing function for receiving the matched signal from the STM-1 link termination function and performing ATM cell generation / termination, generation / removal of unassigned and idle cells, and cell header conversion; It performs user parameter control algorithm (UPC) function for ATM virtual path and virtual channels to prevent ATM cell traffic congestion of the switching system due to ATM cell traffic overload condition in internal switch link of switching system. A traffic management function for extracting and reporting the traffic parameters of the virtual channels; An output stage STM-1 synchronization unit for synchronizing ATM cell streams from a plurality of subscriber links through a user parameter control function at an STM-1 rate through the traffic management function; A switching module connection optical transmitter / receiver for multiplexing the cell stream outputted through the output stage STM-1 synchronizer into an optical signal or performing a reverse function thereof; And a subscriber that transmits OAM information about the cell stream when the cell stream is transmitted through the ATM cell processing function, or generates and transmits an alarm cell and a maintenance cell for a specific connection failure situation. It is configured to include a board control processing unit, characterized in that to accommodate a plurality of subscriber links in a single subscriber link access board.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a connection between a large-capacity ATM switching system and an ATM subscriber of an ATM-based high-speed public information communication network to which the present invention is applied. As described above, the STM-1 optical link is used using only one core. It shows a state where bidirectional communication of ATM subscriber cell stream is possible.

That is, as shown in the figure, between the ATM subscriber (VOD video terminal 100, multi-generation residential subscriber 200, work type subscriber 300, PCS-ATM network interworking device 400, and a large capacity ATM switch 500) The optical link connected to the two-way transmission allows one-way transmission through one line.

FIG. 2 is a detailed block diagram showing the internal structure of the SALUA 50 of the present invention enabling the state as shown in FIG. 1, terminating the STM-1 speed optical signal transmitted from the ATM subscriber side through the optical link interface. A WDM interface function unit 51 for terminating 16 WDM links having bidirectional communication functioned through a 1-core optical link; Generation and termination of 155.52 Mbps signals according to 'ITU-T' recommendations, generation and termination of STM-1 frames, cell extraction / mapping, idle cell processing and headers for signals input through the WDM interface function unit 51 An STM-1 class link termination function unit 52 for performing a function related to generating an error check sum (HEC); ATM cell processing function unit 53 which receives the matched signal from the STM-1 class link termination function unit 52 and performs ATM cell generation / termination, generation / removal of unassigned and idle cells, and cell header conversion. )Wow ; User parameters for ATM Virtual Path (VP) and Virtual Channel (VC) to prevent ATM cell traffic congestion of the switching system due to ATM cell traffic overload in the switch internal switch system. A traffic management function 54 for performing a control algorithm (UPC) function and extracting and reporting traffic parameters of a link, a virtual path (VP), and a virtual channel (VC); An output stage STM-1 synchronizer 55 for synchronizing the ATM cell streams from the 16 subscriber links through the traffic management function 54 at the STM-1 rate; Multiplexing the cell stream output through the output terminal STM-1 synchronizer 55 into 2.5Gbps optical signals and transmitting them to a switching module (not shown in the figure (module mounted inside the switch)) of the switching system, or exchanging A switching module connection optical transmitting / receiving unit 56 for demultiplexing a 2.5 Gbps optical signal from the cell stream transmitted from the system switching module; And extracting and reporting the performance-related coefficients of the physical layer for the cell stream when the stream is transmitted through the ATM cell processing function 53, and recording and reporting on the detection, recovery, occurrence, and release of physical layer failure conditions. In addition to physical layer fault management, performance monitoring, connectivity checks, and loopback of ATM virtual paths and virtual channels are performed and the results are reported, or alert cells and maintenance cells are generated for specific connection failure conditions. Subscriber board control processing unit 57 performs a function for transmitting by.

FIG. 3 is a block diagram showing the WDM interface function unit 51 shown in FIG. 2 in detail. The STM-1 optical signal transmitted from an ATM subscriber is applied to one optical core and one WDM scheme. By using the design coupler 511, bidirectional communication is performed while satisfying a signal stabilization of 27 to 30 dB.

At this time, the STM-1 class optical signal is received from the ATM subscriber using a 1310 nm wavelength photonic diode (PD) 512, and the STM-1 class optical signal is transmitted to the ATM subscriber side using a 1550 nm wavelength laser diode. (Laser Diode: LD) 513 is terminated by using a laser diode (LD), which also transmits and receives at the ATM subscription side, and a coupler using a WDM type coupler at the photodiode (PD) stage. Enables sending / receiving through core.

When the signal received from the subscriber is transmitted to the switch and the signal received from the switch is transmitted to the subscriber, this is performed through the STM-1 link termination function 52.

The ATM cell processing function unit 53 includes: receiving user cell storage means 531 for storing a cell stream received through the STM-1 class link termination function unit 52; After storing the control message generated by the subscriber board control processing unit 57 (this is an internal control command to be transmitted to another unit (not shown)), the data stored in the receiving user cell storage unit 531 is stored. Transmitting IPC cell storing means 532 for transmitting together as necessary when transmitting to the exchange side; Receiving OAM storage means 533 for storing data corresponding to OAM information among the data stored in the receiving user cell storage means 531; And a connection information table 534 for storing information used for data matching to confirm whether the data input to the receiving user cell storage means 531 is normally input data. Each of the storage means is composed of a transmitting / receiving end and used for bidirectional communication. In the present invention, since 16 subscribers are basically processed, each of 16 transmitting / receiving ends is mounted on one board.

Compared to the existing method, if the user wants to accept 16 subscribers through the existing method, 32 lines are needed for the optical core for transmission / reception, and one transmission / reception processing unit is composed of 16 boards. I need a board.

However, since the present invention transmits / receives a single core, only 16 cores of cores need to be used, and since it is also mounted on one board, the subscriber access device can be implemented with a simple configuration.

FIG. 4 is a detailed block diagram of the switching module optical transmission / reception function unit 56. An input register for receiving signals of synchronized 16 lines (Tx1 to Tx16) transmitted through the output terminal STM-1 synchronization function unit 55 is shown in FIG. 561, a multiplexer 562 for multiplexing a signal output from the input register 561 and outputting a single signal, and a clock required for the multiplexing operation in the multiplexer 562. A timing generator 563 supplied to the input register 561 and the multiplexer 562, and a main clock provided from the exchanger to output one 2.5 Gbps optical signal output from the multiplexer 562. A multiplexer (MUX) 565 consisting of an output register 564; An input register 566 that receives the 2.5 Gbps optical signal input from the exchange side, a demultiplexer 567 that demultiplexes the optical signal output from the input register 566 into 16 signals, and outputs 16 signals; An output register 568 for outputting the STM-1 level signals of the 16 lines output from the demultiplexer 567 to the receiving side Rx1 to Rx16 of the STM-1 level link termination function, and the main supplied from the exchanger. The demultiplexer (DEMUX) 600 includes a timing and a controller 569 for receiving a clock and controlling timing when the demultiplexer 567 operates and the output register 568 operates.

Referring to the operation of the subscriber access device of the present invention configured as described above, when the optical signal generated from the ATM subscriber is input through the WDM type coupler shown in FIG. 3, the signal is inputted in the WDM interface functional unit H of SASUA. Received via coupler 511.

Subsequently, the signal is converted into a 155, 52 Mbps signal through the STM-1 class link termination function unit 52, and then stored in the receiving user cell storage unit 531 in the ATM cell processing function unit 53. Under the control of the subscriber board control processing unit 57, it is determined by comparing the data in the connection information table 534 which confirms whether or not the data is normal data.

This signal is then input to the receiving end RX of the STM-1 synchronization unit 55, and at the same time the traffic parameters are extracted by the traffic management function 54 through the control of the subscriber board control processing unit 57, thereby Entered into management function 54, these parameters are used to prevent ATM cell traffic congestion to perform user parameter control algorithm functions for ATM virtual paths and virtual channels.

In addition, the result value performed by the algorithm is received user cell storage means 531 to be used as the path and channel information when the signal from the ATM subscriber input through the STM-1 class link termination function unit 52 is input into the exchange. ) Is entered.

On the other hand, if the message to be transmitted to the other part in the transmission IPC cell storage means 532 for storing the control message generated by the subscriber board control processing unit 57 when the signal is input to the STM-1 synchronization unit 55 When data is transmitted from the receiving user cell storage unit 531, the data is transmitted together, and data corresponding to the OAM information during transmission is stored in the OAM storage unit 533 and used to manage the access device.

Then, the 16 subscriber signals inputted to the STM-1 synchronization unit 55 are synchronized at the STM-1 level, and 16: 1 multiplexed through the multiplexer 562, and then converted into optical signals through the output register 564. It is changed and finally entered into the switch network part of the exchange.

On the contrary, the signal output in the exchange is demultiplexed 1: 16 through the demultiplexer 567, and is then input to the ATM cell processing function unit 53 and stored in each storage means as described above. It is transmitted to the ATM subscriber via the unit 51.

As described in detail above, the present invention is economical and simple, which enables two-way communication using one core to accommodate two-way communication using two cores to accommodate multiple subscriber links in a single subscriber board. Provides a subscriber board of functional structure.

In addition, a preferred embodiment of the present invention is disclosed for the purpose of illustration, those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (5)

A WDM interface function unit for terminating an STM-1 speed optical signal transmitted from an ATM subscriber side through an optical link interface and terminating a plurality of WDM links capable of bidirectional communication through a 1-core optical link; An STM-1 class link termination function unit for performing STM-1 class frame generation and termination functions on the optical signal input through the WDM interface function unit; An ATM cell processing function unit for receiving the matched signal from the STM-1 class link termination function unit to perform ATM cell generation / termination, generation / removal of unassigned and idle cells, and cell header conversion; It performs user parameter control algorithm (UPC) function for ATM virtual path and virtual channels to prevent ATM cell traffic congestion of the switching system due to ATM cell traffic overload condition in internal switch link of switching system. A traffic management function for extracting and reporting the traffic parameters of the virtual channels; An output stage STM-1 synchronization unit for synchronizing ATM cell streams from a plurality of subscriber links through a user parameter control function at an STM-1 rate through the traffic management function; A switching module connection optical transmitter / receiver for multiplexing and transmitting the cell stream outputted through the output stage STM-1 synchronization unit to an optical signal or performing a reverse function thereof; And a subscriber that transmits OAM information about the cell stream when the cell stream is transmitted through the ATM cell processing function, or generates and transmits an alarm cell and a maintenance cell in response to a failure of a specific connection. A subscriber link access device (SALUA) of an asynchronous transfer mode (ATM) exchange configured to include a board control processing unit and to accommodate multiple subscriber links in a single subscriber link access board. The apparatus of claim 1, wherein the WDM interface function unit comprises: a coupler, which is an optical device using a WDM scheme for receiving an STM-1 optical signal transmitted from an ATM subscriber; An optical device receiving the STM-1 optical signal through the coupler; And a laser device transmitting to the ATM subscriber side through the STM-1 link termination function transmitted from the exchange side to the subscriber link connection device of the asynchronous transfer mode (ATM) exchange. SALUA). The method of claim 2, wherein the ATM subscriber side also transmits / receives a laser device for transmission to and from the WDM interface function unit, and a WDM-type coupler is connected to an optical device terminal to bi-directionally flow the cell stream through one core between the couplers. Subscriber link access device (SALUA) of an asynchronous transfer mode (ATM) exchange, characterized by enabling transmission / reception. The system of claim 1, wherein the ATM cell processing function unit comprises: receiving user cell storage means for storing a cell stream to be received through an STM-1 class link termination function; Transmitting IPC cell storing means for storing the control message generated by the subscriber board control processor and transmitting the data stored in the receiving user cell storing means to the exchange side as necessary; Receiving OAH storage means for storing data corresponding to OAH information among the data stored in the receiving user cell storage means; And a connection information table for storing information used for data matching to confirm whether the data inputted to the receiving user cell storage means is normally inputted data of the asynchronous transmission mode (ATM) exchange. Subscriber Link Access Device (SALUA). The method according to claim 1, wherein each of the storage means is composed of a transmitting and receiving end is used for two-way communication, based on the processing for 16 subscribers, each of the 16 transmitting and receiving end is mounted on one board to form a group A subscriber link connection (SALUA) of an asynchronous transfer mode (ATM) exchange.

Images