KR100256691B1 - Optical trasmission system for arbitrary combination of tributaries - Google Patents

Abstract

PURPOSE: An optical transmission apparatus for accepting a subordinate signal resulted from certain combination of signals, is provided to accommodate all signals having various transmission speeds, and transmit them to a single optical line at a high speed, without relation to a transmission speed of the subordinate signal in synchronous transmission. CONSTITUTION: An optical amplification part(10) amplifies an optical signal. A clock generation part(20) generates a system clock which is synchronized by a reference signal received from an external unit, and provides a frame synchronization signal. A subordinate signal process part(30) performs a process function for receiving and transmitting optical signals, in response to the system clock and the frame synchronization signal. A main signal process part(40) multiplexes a signal received from the part(30), and thereby converts it to an optical signal. The part(40) reversely multiplexes the optical signal from the part(10). The part(40) further converts the data which is transmitted via the part(30), to an electric signal.

Description

Optical transmission device that accepts any combination of dependent signals

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission device, and more particularly, to an optical transmission device for accommodating any combination of dependent signals capable of transmitting signals regardless of the combination of dependent signals in synchronous transmission.

Conventionally, the optical transmission device has been developed up to 2.5 Gb / s (STM-64) up to a maximum capacity of 2.5 Gb / s that can be transmitted through a single optical path.

Therefore, with the development of the information industry, the amount of information required has increased and the transmission capacity of transmission lines between stations has been steadily required.However, the method of increasing the transmission capacity through the expansion of optical lines has a huge cost for laying the optical lines. There was a limit to the capacity.

As a solution to this problem, there is a method of increasing transmission capacity by increasing transmission speed while using an existing optical path. To implement this effectively, an optical transmission device of various transmission speeds that are already installed and used is used as it is. There is an urgent need for a device to enable this.

Accordingly, the present invention has been made to solve the above problems, in the synchronous transmission to receive all signals for multiple transmission rates regardless of the transmission speed of the dependent signal to transmit at high speed using a single optical path It is an object of the present invention to provide an optical transmission device for receiving any combination of dependent signals.

1 is a block diagram of an embodiment of an optical transmission device that accepts any combination of dependent signals in accordance with one embodiment of the present invention;

FIG. 2 is a block diagram of an embodiment of the system clock generator of FIG. 1; FIG.

Explanation of symbols on the main parts of the drawings

10: optical amplifier 20: system clock generator

30: slave signal processor 40: main signal processor

50: network management unit 60: system monitoring control unit

Optical transmission device of the present invention for achieving the above object, the optical amplification means for amplifying the optical signal; Clock generation means for generating a system clock synchronized with a reference signal received from the outside and providing the system clock with a frame synchronization signal having a predetermined period; Dependent signal processing means for performing a connection function to transmit and receive a plurality of optical signals according to the system clock and frame synchronization signal; And converting the signal received from the dependent signal processing means into an optical signal, and conversely receiving and demultiplexing the optical signal from the optical amplifying means, receiving the dependent signal as an electrical signal, and receiving the dependent signal processing means. And main signal processing means for transmitting data for transmission via an electrical signal.

In addition, the optical transmission device for receiving the dependent signal of any combination of the present invention, network configuration means for producing and outputting the data for the performance and history management of the entire system in the configuration as described above; And system monitoring control means for monitoring the alarm, operation status and performance of the means to perform the switching and control, and reporting the result to the network management means.

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

Referring to FIG. 1, an optical transmission device that accommodates a combination of dependent signals of the present invention includes an optical amplifier 10, a clock generator 20, a dependent signal processor 30, and a main signal processor 40. And a network management unit 50 and a system monitoring control unit 60.

The optical amplifier 10 is configured of a block that amplifies the optical signal with a sufficient gain to apply the optical signal of the STM (Synchronous Transfer Mode) -64 level to the line or vice versa and input it to the optical receiver.

The system clock generator 20 receives a signal from an external clock source, generates a clock synchronized with the signal, and distributes and supplies it with the frame synchronization signal FS of 8 kHz to the entire system.

FIG. 2 is a block diagram of an exemplary embodiment of the system clock generator of FIG. 1.

As shown in FIG. 2, the system clock generator of FIG. 1 includes a reference clock selector 23, a reference clock monitor and control unit 24, a synchronous clock generator 25, and a system clock output unit 26. ) And a system clock output control unit 27.

The reference clock selector 23 uses an external network synchronizer clock source (DOTS) (not shown), a received STM-64 line signal, or a slave signal of STM-16 / STM-4 / STM-1 as an input reference clock. The selection as the reference clock is determined by the system monitoring control unit 60 after determining the priority of the input reference clock available at the initial startup of the device.

The reference clock monitoring and control unit 24 controls the selection of the reference clock by requesting an interrupt from the system monitoring control unit 60 so as to monitor whether the primary reference clock has failed and to automatically switch over. When the generation occurs, it controls to supply the clock to the system through self-oscillation, and also monitors whether the failed reference clock is recovered and reports it to the system monitoring controller 60.

The synchronous clock generator 25 generates a clock synchronized with an input reference clock. The synchronous clock generator 25 performs external synchronization, loop synchronization, phase hold, and self-locking. Operate in FREE-RUNNING mode.

In the external synchronization mode, a clock synchronized with a clock selected by a reference clock selector among a plurality of 2.048 MHz supplied from an external network synchronizer clock source (DOTS) is supplied to the system. In the loop synchronizing mode, a clock synchronized with a clock selected by the reference clock selector among a plurality of 8 KHz supplied from an optical receiver (not shown) is supplied to the system. In the phase preservation mode, when an abnormality occurs in the reference clock supplied from an external remote synchronizer clock source (DOTS) or the optical receiver, the clock having the phase so far is supplied to the system without any further phase tracking. In the self oscillation mode, when there is no reference clock input from the outside, a fixed clock is supplied to the system using an oscillator in a loop.

The system clock output unit 26 generates the 51/78/38 MHz clock and frame signals required for the system from the 155.520 MHz generated by the synchronous clock generator.

The system clock output control unit 27 controls the output of the system clock to realize redundancy in preparation for a failure of the system clock output unit.

The slave signal processing unit 30 performs an STM-16 connection unit 31, an STM-4 connection unit 32, and an STM-1 connection unit that perform processing functions for transmitting and receiving STM-1, STM-4, and STM-16 optical signals. And a high speed signal connection section 34 which performs a connection function with the main signal processing section 40.

The STM-16 connection unit 31 receives the 2.5Gb / s optical signal of the STM-16 system, recovers the clock and data, converts the data into 52M 48 data streams, and transmits the data to the high speed signal connection unit 34. It receives 52Mb / s data from 34) and converts it to 2.5G optical signal of STM-16 level and outputs it.

The STM-4 connection unit 32 receives the 622M optical signal of the STM-4 hierarchy, recovers the clock and data, converts the data into 12 data streams of 52 Mb / s, and transmits the data to the high speed signal connection unit 34. In contrast, the high speed signal connection unit 34 Receives 52Mb / s data from) and converts it into 622Mb / s optical signal of STM-4.

The STM-1 connection unit 33 receives the 155Mb / s optical signal of the STM-1 hierarchy, recovers the clock and data, converts the data into three 52Mb / s data streams, and transmits them to the high speed signal connection unit 34. It receives 52M data from 34 and converts it into 155Mb / s optical signal of STM-1 level.

The high speed signal connection unit 34 receives the 622Mb / s electric signal from the main signal processing unit 40 as a 50 Ohm twisted pair cable, performs reframe, demultiplexing, and descrambling, respectively, and receives 52Mbps data and 52MHz. It converts into clock and 8KHz frame pulse and transmits to STM-16 connection, STM-4 connection and STM-1 connection (31, 32, 33) and vice versa STM-16 connection, STM-4 connection and STM-1 Receives 52 Mbps data, 52 MHz clock, and 8 KHz frame pulses from the connections 31, 32, and 33, aligns the access unit frame by pointer processing, inserts A1 and A2 bytes, and after scrambling for 622 Mbps transmission Multiplexing to 622Mbps serves to transmit to the main signal processor 40.

The main signal processor 40 converts the signals received from the slave signal processor 30 into 10Gb / s optical signals, and conversely receives and demultiplexes the 10Gb / s optical signals, and the STM-64 multiple demultiplexer. (41, 42) and the slave signal connection unit 43 for receiving the slave signal as a 622Mb / s electrical signal and on the contrary transmits the data for transmission through the slave signal processor 30 as a 622Mb / s electrical signal Maps STM-1, STM-4 and STM-16 signals to STM-64 frames, converts them into optical signals, sends them as 10Gb / s optical signals, and conversely recovers the clock using the received 10Gb / s optical signals, It also recovers the data and demultiplexes it with each dependent signal. The physical configuration is that the housed main unit is designed in a "1 + 1" redundancy structure and mounted on a two-layer shelf of one backboard.

The photoelectric conversion unit 41 receives a 10Gb / s electrical signal from the STM-64 multiple demultiplexer 42, converts the signal into an optical signal, and transmits the optical signal, and conversely, 10Gb received by the optical amplifier 10. / s converts the optical signal into an electrical signal, recovers the clock using the converted signal, and latches data to the recovered clock to provide 10G data and a clock to the STM-64 multiple demultiplexer 42. When no optical signal is received, a signal loss signal indicating no optical signal is output.

The STM-64 multiple demultiplexer 42 multiplexes 128 78 Mb / s signals received from the slave signal connection 43 into 10 Gb / s signals, and the multi-section overhead (MSOH) and the relay section over the STM-64 signal. Performs head (RSOH) insertion and firstly 8: 1 multiplexes a total of 128 78Mb / s signals to produce 622Mb / s signals, and 16: 1 multiplexes these 622Mb / s signals to produce 10Gb / s signals. Perform.

In the relay section overhead (RSOH) processing, 16 622M data and a clock are descrambled and decoded by 1: 8, and then 78M 128 are transmitted to the slave signal access unit 43. Further, the value of the B1 byte is extracted and compared with the BIP-8 calculated value of the received data to check the state of the received data. Then, A1 and A2 bytes are extracted and checked for reframes.

In the multi-section overhead (MSOH) processing, 128M 128 bits are received to extract and process the multi-section overhead interval byte. Also, it receives a signal loss signal from the photoelectric conversion unit 41 and sends a system clock to the lower board when the signal is lost.

The slave signal connecting unit 43 connects the slave signal processing unit 30 and the main signal processing unit 40 of the single-station 10Gbps optical transmission system and simultaneously performs a synchronization function by pointer processing. Reframe, demultiplex and descrambling after receiving 622Mbps electrical signal of STM-64 multiple by converting into multiple H-buses composed of 78Mb / s data, 78MHz clock and 8KHz frame pulse Transmits to the demultiplexer 42, and vice versa, receives a plurality of H-buses composed of a large number of 78 Mbps data, 78 MHz clock, and 8 KHz frame pulses from the STM-64 multiple demultiplexer 42, and is accessed by pointer processing. It arranges the unit frames, inserts A1 and A2 bytes, and performs a scrambling process for 622 Mbps transmission, and then multiplexes them to 622 Mbps to transmit them to the slave signal processor 30.

The network manager 50 collects and outputs the interworking status and available status data of the entire network by monitoring the operation, performance, and alarm status of a plurality of transmission related systems.

The system monitoring and control unit 60 collects the performance, alarm, and operation state data of each block of the single station type 10G optical transmission system, and performs functions such as unit switching and line switching in the system, and transmits the same to the network management unit 50. Perform the function of reporting.

Referring to the operation of the optical transmission device that accommodates the combination of the dependent signal of the present invention having the above structure as follows.

First, a process in which the dependent signal is input, converted into an STM-64 signal, and output is described.

When the STM-16, STM-4 and STM-1 are input to the respective STM-16 connection, STM-4 connection and STM-1 connection 31, 32, 33 from the existing transmission device, the STM-16 connection, STM The -4 connector and the STM-1 connector (31, 32, 33) receive the optical signal of the corresponding level, recover the clock and data, convert it into a 52M data sequence, and transmit it to the high-speed signal connector 34, and the high-speed signal connector ( 34) receives 52 Mbps data, 52 MHz clock, and 8 KHz frame pulses from the STM-16, STM-4, and STM-1 connections (31, 32, 33) to align the access unit frames using pointer processing. After converting to 78 Mbps, A1 and A2 bytes are inserted, scrambling, and then multiplexed to 622 Mbps to be transmitted to the slave signal access unit 43. The slave signal connection unit 43 receives and reframes 16 622 Mbps electrical signals from the slave signal processing unit 30 and descrambles the 8 groups of 78 Mbps in 16 bundles, and then descrambles them to eight 78 Mbps, 78 MHz clock, and 8 KHz frames. It converts into 16 H-buses composed of pulses and transmits them to the STM-64 multiple demultiplexer 42 via the backplane. In the STM-64 multiple inverse multiplexer 42, the 128 78 Mb / s signals received from the slave signal connection 43 are multiplexed into 10 Gb / s signals to compensate for the phase difference generated between the 78M data inputted, and the MSOH insertion and B2 calculation are performed. (BIP 64x16), E2 serial communication channel processing, parallel communication channel processing using data bus with K1 / K2, S1, M1 supervisory control device, relay section overhead (RSOH) insertion, A1, A2 frame byte insertion, B1 calculation (BIP-8), J0 / C1 processing, 128 multiplexed 78Mb / s signals (10Gb / s) into 622Mb / s signals, then 16: 1 multiplexed 16 622Mb / s signals to STM-64 electrical Synthesize a signal and output it to the photoelectric conversion unit 41. The photoelectric conversion unit 41 converts the STM-64 electrical signal into an optical signal and outputs the optical signal to the optical amplifier 10. The optical amplifier 10 amplifies the power of the received optical signal and inputs it to the optical path.

The following describes a process of outputting the signal of the slave unit from the 10G optical signal.

The optical amplifier 10 amplifies the received STM-64 optical signal sufficiently and outputs it to the photoelectric conversion unit 41. The photoelectric conversion unit 41 converts the received optical signal into an electrical signal, extracts the data and the clock therefrom, and outputs the 10G data and the clock to the STM-64 multiple demultiplexer 42. In the STM-64 multiple demultiplexer 42, the demultiplexer receives 9.95328 Gb / s data and a clock signal from a clock extractor (not shown) of the optical receiver and receives 16 622M data and a clock. And 1: 8 reverse multiplexing to transfer the 128 78M to the slave signal connection 43. Further, the B1 byte value is extracted and compared with the BIP-8 calculated value of the received data to check the state of the received data. Then, A1 and A2 bytes are extracted and checked for reframes. The 10Gb / s Synchronous Digital Hierarchy (SDH) structure detects and processes information of a relay section overhead (RSOH) and a multi-section overhead (MSOH) section and performs a reframe function at 622M class. The slave signal connection unit 43 receives 16 H-buses consisting of eight 78 Mbps data and a 78 MHz clock and an 8 KHz frame pulse, aligns the access unit frame by inserter processing, inserts A1 and A2 bytes, and transmits 622 Mbps for transmission. After the scrambling process, the signal is multiplexed to 622Mbps and transmitted to the high speed signal connection unit 34 of the dependent signal processing unit 30. The high-speed signal connection unit 34 receives and reframes a 622 Mbps electrical signal from the slave signal connection unit 43, descrambles by demultiplexing the signal into eight 78 Mbps, converts it to 12 52 Mbps, a 52 MHz clock, and an 8 KHz frame pulse, and transmits the STM through the backplane. -16 connections, STM-4 connections and STM-1 connections 31, 32, 33. In the STM-16 connection, STM-4 connection and STM-1 connection (31, 32, 33), the received 52Mbps signal is converted into the signal of the corresponding STM-16, STM-4, STM-1 level, and then converted into an optical signal. It will transmit to other STM-16, STM-4 and STM-1 level transmitters. In addition, the system clock generator 20 provides a system clock and a frame synchronization signal. When an external 2M reference signal is input, the system clock generator 20 provides a clock synchronized thereto. When there is no reference input, the main signal processor 40 The 8kHz clock is received from the slave signal processor 30 to provide a clock synchronized with one of these signals.

On the other hand, the system monitoring and control unit 60 performs the switching and control by monitoring the operation state, performance, and alarm of each functional block in the whole process, and reports it to the network management unit 60. The network manager 60 creates and outputs data for performance and history management of the entire apparatus.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the optical transmission device that accommodates the combination of various kinds of dependent signals of the present invention provides the integrated transmission of STM-1, STM-4, and STM-16, which are used in the existing optical transmission network, in one transmission path. This not only allows the transmission capacity to be extended to 10Gb / s, but also accommodates any combination of STM-1, STM-4, and STM-16 signals, making it possible to utilize optical paths and optical transmission devices already installed in the standard. By maximizing the efficiency, the economics are remarkably improved, the signal wiring in the device is simple, and the miniaturization is easy. In addition, as the transmission speed increases due to the use of the present invention, there are also ramifications such as introduction of various services and reduction of transmission cost of users.

Claims (6)

Optical amplifying means for amplifying the optical signal; Clock generation means for generating a system clock synchronized with a reference signal received from the outside and providing the system clock with a frame synchronization signal having a predetermined period; Dependent signal processing means for performing a connection function to transmit and receive a plurality of optical signals according to the system clock and frame synchronization signal; And The signal received from the dependent signal processing means is multiplexed and converted into an optical signal, and on the contrary, the optical signal from the optical amplifying means is received and demultiplexed, the dependent signal is received as an electrical signal, and through the dependent signal processing means. Main signal processing means for transmitting data for transmission as an electrical signal Optical transmission device for receiving a dependent signal of any combination consisting of. The method of claim 1, The system clock generating means, Reference clock selecting means for using a light path signal or a plurality of dependent signals as an input reference clock, and selecting a priority of the input reference clock; First, the selection of the reference clock is controlled to automatically switch over by monitoring the failure of the reference clock, and when a failure occurs in all of the available reference clocks, the clock is supplied to the system through its own oscillation. In addition, reference clock monitoring and control means for monitoring and reporting whether or not the failure of the reference clock recovery; Synchronous clock generation means for generating a clock synchronized with the input reference clock; System clock output means for generating a system clock and a frame signal necessary for the system from the synchronous clock generated by the synchronous clock generating means; And System clock output control means for controlling the output of the system clock for redundancy in case of failure of the system clock output means Optical transmission device for receiving a dependent signal of any combination consisting of. The method of claim 1, The dependent signal processing means, First to third connecting means for receiving an optical signal, recovering a clock and data, converting the data into a plurality of data streams, and transmitting the converted data; And Receiving the electrical signal from the signal processing means and performing reframe and demultiplexing respectively, and then converting the data, the clock and the frame pulse to the first to the third connecting means, and also the first to the third High speed signal connection means for receiving data, clock and frame pulses from the connection means and arranging the access unit frames by the pointer processing to transmit them to the signal processing means. Optical transmission device for receiving a dependent signal of any combination consisting of. The method of claim 1, The signal processing means, Converts the received electrical signal into an optical signal, converts the optical signal received from the optical amplification means into an electrical signal, recovers a clock using the converted electrical signal, and latches data in the recovered clock. Photoelectric conversion means for providing said data and clock; Multiple demultiplex means for multiplexing a plurality of received data signals and remultiplexing the multiplexed signals; And Subordinate signal connecting means for connecting between the dependent signal processing means and the signal processing means and at the same time performing a synchronization function by pointer processing Optical transmission device for receiving a dependent signal of any combination consisting of. The method of claim 1, Network management means for creating and outputting data for performance and history management of the entire system; And System monitoring control means for monitoring the alarm, operation status and performance of the means to perform the switching and control, and report the result to the network management means The optical transmission device further comprising a dependent signal of any combination. The method of claim 3, wherein The first connection means connects the slave signal of the STM-16 hierarchy, the second connection means connects the slave signal of the STM-4 hierarchy, and the third connection means connects the slave signal of the STM-1 hierarchy Optical transmission device for receiving any combination of the dependent signal, characterized in that.

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