KR100304724B1 - Channel cross linking device in optical transmission device - Google Patents

Abstract

The present invention relates to a channel cross linking device in an optical transmission device.

The present invention provides a BLSR / 2 (Bidirectional Line-Switched Ring / 2) network connected through a transmission optical path and a reception optical path having a predetermined number of working channels and a protection channel. In case that there is a failure in the optical path between the transmitting optical transmitter which is to be used to transmit data and the receiving optical transmitter which will receive this data, It transmits the data to be transmitted through the failed optical path from the device to the protection channel of the opposite optical path for the failure and transmits it to the receiving optical transmission device.

The present invention is used in an optical transmission device, and performs a time slot interchange function by cross-linking a channel line, thereby efficiently implementing a bidirectional line-switched ring / 2 (BLSR / 2) network. It can be used as

Description

A channel crossing unit in Fiber Loop Carrier systems

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a channel cross linking device in an optical transmission device, and in particular, used in an Add / Drop Control Unit (ADCU) of a synchronous optical transmission device, and outputting from an Add / Drop Control Unit (ADCU). The present invention relates to a device that enables a Bidirectional Line-Switched Ring / 2 (BLSR / 2) function by performing a time slot interchange (TSI) function by cross-connecting a channel line.

FIG. 1 is a block diagram of a 2.5 Gigabit optical transmission apparatus to which the present invention can be applied, in which 16 synchronous transport module signals (STM-1) transmit and receive multiplexed signals through optical paths. In this case, since one synchronous transport module signal STM-1 has a transmission rate of 155.52 Mbps, the 16 synchronous transport module signals STM-1 have a transmission rate of exactly 2,488.32 Mbps, but generally 2.5 gigabit ( Giga Bits) is called optical transmission device.

The 2.5 Gigabit optical transmission device 100 is an optical amplification unit 110 for receiving and amplifying an optical signal having a transmission rate of 2.5 Gigabit, the optical signal received from the optical amplification unit 110 and the synchronous transport module signal-16 First optical connection unit 121, administrative unit signal (AU), synchronous transport module signal-1 (STM-1), or synchronous transport module signal-4 (STM-) connected at the (STM-16) level 4) Add / drop to switch the signals received from the second optical connection unit 122, the first optical connection unit 121, and the second optical connection unit 122, which are connected to the class signals, at the management unit signal level. The first slave unit 141 which adds / drops the signal switched by the control unit 130 and the add / drop control unit 130 as an E3, T3, E4, or STM-1 signal according to the type of the external device. A second subordinate unit 142 for outputting the signal switched by the control unit 130 as an E1-class signal, Monitoring and control of a data communication connection unit 150 for relaying data communication channel data (DCC Data), a clock supply unit (160: digital office timing supply) for supplying a clock signal, and an optical transmission device It consists of a supervisory control unit 170 in charge of the function.

Of course, each component described above also performs the transmission function by performing the reverse function.

On the other hand, the add / drop control unit (ADCU) is configured to transmit the same data in both directions (east and west) when the optical transmitters as shown in FIG. 1 are configured in a unidirectional path-switched ring (UPSR) type. In the receiving operation, the same data received in both directions (east and west) is selected and received.

In this case, the reception operation generally receives a signal from the west, and receives a signal from the east when a failure occurs. Thus, the total capacity in a unidirectional path-switched ring (UPSR) type network cannot exceed STM-16.

On the other hand, the BLSR / 2 (Bidirectional Line-Switched Ring / 2) network has a working channel and a protection channel on the same optical path, so that the transmission channel and the reception channel are opposite to each other. The format to place in. That is, when a failure occurs on one ring line, ring switching is performed and the service channel is switched to the protection channel on the opposite ring.

In a BLSR / 2-enabled network, one ring capacity between adjacent optical transmitters is STM-16 / 2. Therefore, the BLSR / 2 function network can be used more efficiently in the UPSR function network at its capacity. At this time, in order to switch from one ring line to another ring line in the BLSR / 2 function network, a time slot exchange function (TSI: Time) is used for exchanging data to be transmitted through a fault line to a protection channel of an optical fiber flowing in the opposite direction. Slot Interchange).

Accordingly, the present invention has been made to meet the above needs, and is used in the Add / Drop Control Unit (ADCU) of the synchronous optical transmission device, which is output from the Add / Drop Control Unit (ADCU). The purpose of the present invention is to provide a device that enables a Bidirectional Line-Switched Ring / 2 (BLSR / 2) function by performing a time slot interchange (TSI) function by cross-linking a channel line. have.

In order to achieve the above object, the channel cross-linking device in the optical transmission device according to the present invention is provided through a transmission optical path and a reception optical path each having a predetermined number of working channels and protection channels. It is used in the optical transmission device forming each node of the BLSR / 2 (Bidirectional Line-Switched Ring / 2) network connected to the transmission optical path and the receiving optical path between the optical transmission device and other optical transmission devices. When a failure occurs, it is configured to perform a function of inserting and transmitting data to be transmitted to the other optical transmission device from the optical transmission device to the other optical transmission device through the optical path in which the failure occurs by inserting it into a protection channel of a reverse optical path for failure. It is characterized by.

In this case, the channel cross linking device may include: a first retiming unit configured to receive data to be transmitted to an east node of the optical transmission device and to retime the system clock of the optical transmission device; A second retiming unit configured to receive data received from an east node of the optical transmission device and retime the system clock of the optical transmission device; A third retiming unit for receiving data to be transmitted to a western node of the optical transmission device and retiming the system clock of the optical transmission device; A fourth retiming unit configured to receive data received from a western node of the optical transmitter and retime the system clock of the optical transmitter; The output signal of the first retiming unit and the second retiming unit are respectively input, and the output signal of the second retiming unit is selected and output if the optical path connected to the east node is in a normal state. A first channel cross connection unit configured to transfer a negative output signal to the protection channel and output the first output signal; The output signal of the third retiming unit and the fourth retiming unit are respectively input, and if the optical path connected to the west node is in a normal state, the output signal of the fourth retiming unit is selected and output. A second channel cross connection unit configured to transfer a negative output signal to the protection channel and output the converted channel; A fifth retiming unit retiming the output signal of the first channel cross connection unit to a system clock of the optical transmission device; A sixth retiming unit configured to retime an output signal of the second channel cross connection unit to a system clock of the optical transmission device; An address decoder which decodes an address signal of a central processing unit managing a channel cross linking device in the optical transmission device and enables the first channel cross linking unit and the second cross linking unit; And a latch unit for recording channel crossing information in the first channel cross linking unit and the second cross linking unit.

1 is a block diagram of a 2.5 gigabit optical transmission apparatus to which the present invention can be applied;

2 is a schematic diagram of a BLSR / 2 type network in which the present invention is used;

3 is a schematic diagram of a BLSR / 2 type network shown in terms of a first optical connection unit;

4 is a block diagram of an add / drop control unit (ADCU) in which the present invention is used;

5 is a configuration diagram of an embodiment of a channel cross connection device according to the present invention.

* Explanation of symbols for main parts of the drawings

100: 2.5 Gigabit Optical Transmitter 110: Optical Amplifier

121: first optical connecting portion 122: second optical connecting portion

130: add / drop control unit 141: first subordinate part

142: second slave 150: data communication connection

160: clock supply unit 170: supervisory control unit

210,220,230,240: optical transmission device (node)

241,244: High Speed Transmission Unit (HSTU)

242,243: High Speed Receive Unit (HSRU)

251,252,253,254: pair of bidirectional light paths

131, 132: management unit signal pointer processing unit

133: channel cross connection device of the present invention

134: add / drop control unit 511,512,513,514,517,518: retiming unit

515,516: channel cross connection 519: address decoder

520: latch portion

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

FIG. 2 is a schematic diagram of a BLSR / 2 type network in which the present invention is used. In order to switch from one ring line to another ring line in a BLSR / 2 type network, a time slot exchange function (TSI: Time Slot Interchange) may be used. In the event of a single line failure, the fiber channel's protective channel capacity should be maintained at 50% of the total capacity for complete recovery.

Referring to the 2.5 Gigabit optical transmission apparatus 100 shown in FIG. 1 as an example, the 2.5 Gigabit optical transmission apparatus 100 communicates in units of 16 synchronous transport module signals (STM-1), one synchronous Since the transport module signal STM-1 includes three management unit signals AU-3, the transport module signal STM-1 includes 48 management unit signals AU-3. Therefore, one ring line divides a channel capable of accepting 48 management unit signals in half so as to be used as a service channel and a protection channel, respectively. Therefore, if a failure occurs in one ring line, the protection channel of the other ring line can be used to accommodate all 24 service channels of the failed ring line.

At this time, when one ring line has a failure, the channel number of the ring line that is switched to channel 1 (m number) of the failed ring line is 25 (m + 1).

Now, a description will be given of an operation process when a failure occurs in the BLSR / 2 type network. Here, the hatched portion means the protection channel, and the other portion means the service channel.

Normally, channels 1 to 24 are used as working channels. If a transmission line from node B 240 to node A 210 fails during communication, node A 210 detects this failure. By notifying node C (210) of the failure of node A (210), node A (210) performs Automatic Protection Switching (APS).

That is, data to be sent from node B 240 to node A 210 (indicated by a dotted line) is transmitted to node A 210 via node B 240, node C 230, and node D 220. In this case, the channel used is a guard channel. That is, data originally sent from node B 240 to node C 230 or node D 220 is transmitted using the service channel as it is, but is intended to be sent to node A 210 but failed to send due to the failure of optical path 254. The data is transferred to the protection channel and transmitted to the node A 210. Data transmitted to the node A 210 is transferred to channels 1 to 24 (service channels) and processed.

FIG. 3 is a schematic diagram of a BLSR / 2 type network shown from the perspective of the first optical connection unit, showing data input / output at the first optical connection unit 121 connected to the optical path at each node (optical transmission device) shown in FIG. It is shown.

One first optical connection unit 121 is connected to a corresponding optical path to perform two functions of a high speed transmission unit (HSTU) for transmitting an STM-16 signal, and an STM-16 signal connected to the corresponding optical path It consists of two High Speed Receive Units (HSRUs) that perform the reception function of.

Hereinafter, for convenience of description, a unit for connecting the east node to transmit the STM-16 signal and connecting the east node to the east node high speed transmission unit 244, and a unit for connecting the east node to receive the STM-16 signal and receiving the east node high speed reception unit ( 243), the unit that connects with the western node and transmits the STM-16 signal is called the western node high speed transmission unit 241, and the unit that connects with the western node and receives the STM-16 signal is called the western node high speed reception unit 242. Shall be.

At this time, the optical signal received from the east node high-speed receiving unit 243 and the west node high-speed receiving unit 242 is input to the add / drop control unit 130 (ADCU) for each drop and thru channel. After the pointer processing, the signals to be dropped are sent to the first subordinate unit 141 or the second subordinate unit 142, and the channels to be passed through are transmitted to the corresponding high speed transmission unit.

Meanwhile, when the optical path is in a normal state, the optical transmission apparatus to which the present invention is applied passes through the signal received by the high speed receiving unit as it is, and connects it to the predetermined pointer alignment processing apparatuses 131 and 132.

However, in the event of a failure on the optical path 254 between any nodes (e.g., between Node A and Node B), it blocks the signal received from the failed optical path 254 to perform the BLSR / 2 function, The signal to be transmitted to the failed optical path 254 is transferred to a protection channel of the optical path 253 to be transmitted in the opposite direction.

The channel-converted signal is inputted to the add / drop control unit 130 through the pointer alignment processor and processed, and the data of the protected channel passes through the node C 230 and the node D 220. Sent to Node A 210. In addition, the Node A 210 transfers the received protection channel to the service channel and then exchanges the channel to drop it.

4 is a block diagram of an add / drop control unit 130 (ADCU) in which the apparatus of the present invention is mounted and used.

The add / drop control unit 130 (ADCU) controls the flow of the management unit signal (AU), and the western node high speed reception unit 242, the east node high speed reception unit 243, the first subordinate unit 141, 2 receive the management unit signal (AU) from the slave unit 142 to align the frequency and phase. In addition, a signal to be transmitted to the western optical transmitter 210 by being divided into signals to be added, dropped, or passed with respect to the sorted management unit signal is a western node high speed transmission unit 241. The signal to be transmitted to the east optical transmitter 230 is transmitted to the east node high speed transmission unit 244, and the signal to be dropped is transmitted to the first slave unit 141 or the second slave unit 142.

Specifically, the signal received through the optical path 254 from the western optical transmission device 210 is made of a signal whose frequency and phase are aligned in the management unit signal pointer processing unit 131 and then the addition / drop control unit 134. The signal received through the optical path from the east optical transmission device is also made into a signal in which the frequency and phase are aligned in the management unit signal pointer processing unit, and then is transmitted to the add / drop control unit 134. In addition, the management unit signal transmitted from the first subordinate unit 141 and the second subordinate unit 142 is also input to the add / drop control unit 134.

In addition, the add / drop controller 134 analyzes the input signals and drops the signals to be dropped, that is, the signals to be delivered to the subscriber via the first slave unit 141 or the second slave unit 142. Transfer to the unit 141 or the second subordinate unit 142. In addition, signals to be added, that is, signals inputted from the first subordinate unit 141 or the second subordinate unit 142 and transmitted to the east optical transmitter 230 or the western optical transmitter 210, are routed. Switch to the channel of. Then, a signal to be passed through, that is, a signal to pass as it is from the east light transmitter 230 to the west light transmitter 210 as it is or pass from the west light transmitter 210 to the east light transmitter 230 as it is. Switch the signal to the channel of the path.

In addition, the performance and alarm of the management unit signal (AU) received from the western node high-speed receiving unit 242, the east node high-speed receiving unit 243, the first subordinate unit 141, and the second subordinate unit 142, etc. It monitors and processes the data.

FIG. 5 is a block diagram illustrating an embodiment of a channel cross linking apparatus according to the present invention, and includes an address decoder 519, a retiming unit 511, 512, 513, 514, 517, and 518, a first channel cross connection 515, and a second channel cross connection 518. ), And the latch unit 520.

The address decoder 519 decodes an address signal of a central processing unit (not shown) that is in charge of overall control of the add / drop control unit 130 to thereby decode the first channel cross connection unit 515 and the second channel. The chip select signal CS, which is a signal for selecting the cross connection unit 516, is output.

The retiming unit is composed of six (first retiming unit and sixth retiming unit), and the retiming signal and output signal inputted to the channel cross linking device 133 of the present invention using the system clock of the node. It performs the role of (retiming).

That is, the channel cross linking device may transmit data to the east node high speed transmission unit 244, data received from the east node high speed reception unit 243, data to be transmitted to the west node high speed transmission unit 241, and west node high speed reception unit. The data received at 242 is input, and the data to be transmitted to the east node high speed transmission unit 244 and the data to be transmitted to the west node high speed transmission unit 241 are outputted. Perform.

Meanwhile, the first channel cross connection unit 515 receives the data to be transmitted to the re-timed east node high speed transmission unit 244 and the data received from the east node high speed reception unit 243 to perform channel exchange to perform the east node high speed transmission unit. Output as data to be sent to (244).

At this time, if the optical path connected to the east node is in a normal state, the output signal of the second retiming unit 512 is selected and outputted, and if the failure state, the output signal of the first retiming unit 511 is transferred to the protection channel. This signal is output after being retimed by the fifth retiming unit 517.

The second channel cross connection unit 516 receives data to be transmitted to the re-timed west node high speed transmission unit 241 and data received from the west node high speed reception unit 242 to perform channel exchange to perform a west node high speed transmission unit 241. Output as data to be sent).

At this time, if the optical path connected to the west node is in a normal state, the output signal of the fourth retiming unit 514 is selected and outputted, and if the failure state, the output signal of the third retiming unit 513 is transferred to the protection channel. The signal is output after being retimed by the sixth retiming unit 518.

The latch unit 520 is a component for recording channel cross-linked position information in the apparatus of the present invention, and the operation program of the corresponding node recognizes the channel switched position with reference to this information.

In the present invention, when a failure occurs, when switching a working channel to a protection channel, the channel switching function can be performed, so that the service channel can be switched to any one of the protection channels. have.

In the existing 2.5 Gigabit optical transmitter, the additional / dropout control unit 130 (ADCU) and the fast receiving unit have separate channel switching functions. Therefore, in case of a failure, the high speed receiving unit does not go through the channel. There could not be. However, in the present invention, a channel switching function is added to perform the BLSR / 2 function so that data can be inserted into a desired protection channel during switching, thereby enabling a complete network configuration.

The present invention is used in the add / drop control unit 130 (ADCU) of the synchronous optical transmission device, and cross-connects the channel line (Channel Line) output from the add / drop control unit 130 (ADCU) to exchange time slots ( By performing the Time Slot Interchange (TSI) function, the Bidirectional Line-Switched Ring / 2 (BLSR / 2) function is enabled, thereby enabling the use of the conventional 2.5 Gigabit optical transmission device more efficiently.

Claims (1)

In the optical transmission device constituting a BLSR / 2 (Bidirectional Line-Switched Ring / 2) network connected through a transmission optical line and a receiving optical channel having a predetermined number of working channels and protection channels In A first retiming unit receiving data to be transmitted to an east node of the optical transmission device and retiming the system clock of the optical transmission device; A second retiming unit configured to receive data received from an east node of the optical transmission device and retime the system clock of the optical transmission device; A third retiming unit for receiving data to be transmitted to a western node of the optical transmission device and retiming the system clock of the optical transmission device; A fourth retiming unit configured to receive data received from a western node of the optical transmitter and retime the system clock of the optical transmitter; The output signal of the first retiming unit and the second retiming unit are respectively input, and the output signal of the second retiming unit is selected and output if the optical path connected to the east node is in a normal state. A first channel cross connection unit configured to transfer a negative output signal to the protection channel and output the first output signal; The output signal of the third retiming unit and the fourth retiming unit are respectively input, and if the optical path connected to the west node is in a normal state, the output signal of the fourth retiming unit is selected and output. A second channel cross connection unit configured to transfer a negative output signal to the protection channel and output the converted channel; A fifth retiming unit retiming the output signal of the first channel cross connection unit to a system clock of the optical transmission device; A sixth retiming unit configured to retime an output signal of the second channel cross connection unit to a system clock of the optical transmission device; An address decoder which decodes an address signal of a central processing unit managing a channel cross linking device in the optical transmission device and enables the first channel cross linking unit and the second cross linking unit; And And a latch unit for recording channel crossing information in the first channel cross link unit and the second cross link unit.