JP5759358B2 - Optical transmission system and optical transmission method - Google Patents

Description

  The present invention relates to an optical transmission system that converts an electrical signal into light and transmits it in parallel.

  In recent years, ICT society has been rapidly advancing to exchange information in a wide range of fields, such as digital signage and information appliances, and terminals. With the expansion of ICT, traffic flowing through the backbone network increases year by year, and 100G OTN is currently attracting attention as a next-generation optical communication standard that drives traffic that continues to increase. OTN is an ITU-T G. It is a multiplexing hierarchy of an optical communication network recommended as a standard in 709, and can transmit a wide variety of client signals efficiently and with high reliability. In OTN, OTU1 (2.5 Gbit / s), OTU2 (10 Gbit / s), OTU3 (40 Gbit / s), and OTU4 (100 Gbit / s) are standardized as transmission rates, and 40G and 100G are transmitted in parallel. OTL3.4 (10 Gbit / s × 4) and OTL4.4 (25 Gbit / s × 4) are specified. OTL can transmit a bit rate signal such as 40 G or 100 G using a plurality of inexpensive low bit rate interfaces.

  As a conventional technique for performing parallel transmission, Patent Document 1 realizes parallel transmission by converting a serial electric signal into parallel, and converting the converted signal into light of a different wavelength and transmitting it. Furthermore, the wavelength to be used reduces the skew between lanes by using a wavelength near zero dispersion of the transmission line. In Patent Literature 2, a fixed pattern for frame synchronization is inserted in each lane that performs parallel transmission, and after detecting the fixed pattern on the receiving side, the delay difference generated during transmission is calculated using a method of adjusting the skew of each lane. Compensation.

JP-A-63-59227 JP 2010-130574 A

  In Patent Documents 1 and 2, since transmission is performed with a fixed number of lanes, the bit rate of each lane is fixed. When optical modules having different bit rates are connected as shown in FIG. 1, it is impossible to cope with the same electrical interface. Currently, optical modules have various bit rates such as 2.5 Gbit / s, 5 Gbit / s, 8 Gbit / s, 10 Gbit / s, 25 Gbit / s, 32 Gbit / s, and 40 Gbit / s. For example, when changing from an optical module of 2.5 Gbit / s to an optical module of 8 Gbit / s, or when changing the number of optical modules, the electrical interface corresponding to the optical module of 8 Gbit / s or the changed optical module It is necessary to prepare an electrical interface that can handle the number. As described above, when the electrical interfaces of Patent Document 1 and Patent Document 2 are used, there is a problem that the operation of the optical transmission section is not flexible.

  Therefore, in order to solve the above problems, an object of the present invention is to provide an optical transmission system and an optical transmission method that are flexible in the operation of an optical transmission section.

  In order to achieve the above goal, the present invention includes an adaptive electrical interface that can change the number of signals (number of lanes) to be paralleled and the bit rate in accordance with the type and number of optical modules. In the following description, the adaptive electrical interface is a set of “transmission signal generator” and “multiplexer” and a set of “separator” and “receiver”.

Specifically, the optical transmission system according to the present invention is:
A transmission signal generator that divides a frame signal to be transmitted into a plurality of blocks, distributes the blocks to m (m is an integer equal to or greater than 1) lanes, and outputs a first signal sequence;
The first signal sequence from the transmission signal generation unit is time-multiplexed in units of bits according to a predetermined multiplexing rule, and reassembled into a second signal sequence in parallel in n (n is m ≧ n, a divisor of m) lanes. A multiplexing section;
A transmission optical module that converts each of the second signal sequences from the multiplexing unit into an optical signal;
A receiving optical module that receives each of the optical signals from the transmitting optical module and outputs the second signal train of n lanes in parallel;
A demultiplexer configured to reassemble the second signal sequence from the reception optical module in units of bits according to a demultiplexing rule based on the multiplexing rule, and to output the first signal sequence of m lanes in parallel;
A receiver that receives the first signal sequence from the separation unit and restores the frame signal from the block of the first signal sequence;
Is provided.

Moreover, the optical transmission method according to the present invention includes:
A transmission signal generation procedure for dividing a frame signal to be transmitted into a plurality of blocks, distributing the blocks to m (m is an integer of 1 or more) lanes, and outputting a first signal sequence;
The first signal sequence in the transmission signal generation procedure is time-multiplexed in units of bits according to a predetermined multiplexing rule, and reassembled into a second signal sequence in parallel in n (n is m ≧ n, a divisor of m) lanes. Multiple procedures,
An optical signal transmission procedure for converting each of the second signal sequences in the multiplexing procedure into an optical signal;
A light receiving procedure for receiving each of the optical signals of the optical signal transmitting procedure and outputting the second signal sequence of n lanes in parallel;
A separation procedure for reassembling the second signal sequence in the light receiving procedure in units of bits according to a separation rule based on the multiplexing rule, and outputting the first signal sequence of m lanes in parallel;
Receiving the first signal sequence in the separation procedure, and restoring the frame signal from the block of the first signal sequence;
Execute.

  The multiplexing unit and the demultiplexing unit switch the lane number m of the first signal sequence and the lane number n of the second signal sequence according to a predetermined rule. Therefore, the present invention can provide an optical transmission system and an optical transmission method that are flexible in the operation of the optical transmission section.

  When the transmission signal generating unit of the optical transmission system according to the present invention distributes the block to m lanes, the distribution destination lane of the block is located at the same position of the immediately preceding frame signal as the distribution destination lane of the block. The distribution lanes are rotated differently.

  In the transmission signal generation procedure of the optical transmission method according to the present invention, when the block is distributed to m lanes, the block distribution destination lane is located at the same position of the immediately preceding frame signal. The distribution lane is rotated so as to be different from the lane.

  By rotating the lane, the frame identification bit appears in each lane, so that the lane can be identified without adding a new frame identification bit.

  The optical transmission system according to the present invention detects at least one of the transmission optical module and the reception optical module, and determines the number of lanes for the transmission signal generation unit, the multiplexing unit, the separation unit, and the reception unit. It further comprises a lane identification unit for designating m and the number of lanes n.

  The optical transmission method according to the present invention detects at least one of the transmission optical module and the reception optical module, and determines the number of lanes m in the transmission signal generation procedure, the multiplexing procedure, the separation procedure, and the reception procedure. And a lane identification procedure for determining the number of lanes n is further executed.

  In the present invention, lane identification is performed, and if the type and number of optical modules are changed, this can be determined and automatically changed to the optimum number of lanes.

  The optical transmission system according to the present invention further includes a skew adjustment unit that adjusts a skew between lanes generated in the optical signal between the transmission optical module and the reception optical module by the second signal sequence. Features.

  The optical transmission method according to the present invention is further characterized by further executing a skew adjustment procedure for adjusting a skew between lanes generated in the optical signal by the second signal sequence.

  The present invention can reduce skew between lanes caused by dispersion existing in an optical transmission line.

  The present invention can provide an optical transmission system and an optical transmission method that are flexible in the operation of the optical transmission section.

It is a figure explaining the subject in the conventional optical transmission system. It is a figure explaining the effect of the optical transmission system concerning the present invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining the receiving side of the optical transmission system which concerns on this invention. It is a figure explaining the multiplexing part of the optical transmission system which concerns on this invention. It is a figure explaining the multiplexing part of the optical transmission system which concerns on this invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining the receiving side of the optical transmission system which concerns on this invention. It is a figure explaining the receiving side of the optical transmission system which concerns on this invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining operation | movement of the transmission signal generation part of the optical transmission system which concerns on this invention. It is a figure explaining operation | movement of the multiplexing part of the optical transmission system which concerns on this invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining operation | movement of the multiplexing part of the optical transmission system which concerns on this invention. It is a figure explaining the transmission side of the optical transmission system which concerns on this invention. It is a figure explaining operation | movement of the transmission signal generation part of the optical transmission system which concerns on this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components. Moreover, when it demonstrates without attaching a branch number, it is description common to all the components.

(Embodiment 1)
3 to 7 are diagrams illustrating the configuration of the optical transmission system 301 of the present embodiment. The optical transmission system 301 divides a frame signal to be transmitted into a plurality of blocks, distributes the blocks to m (m is an integer of 1 or more) lanes in parallel, and outputs a first signal sequence. The first signal sequence from the transmission signal generation unit 10 is time-multiplexed in bit units according to a predetermined multiplexing rule, and reassembled into a second signal sequence in parallel in n (n is m ≧ n, a divisor of m) lanes. The multiplexing unit 20, the transmission optical module 30 that converts the second signal sequence from the multiplexing unit 20 into an optical signal, and the second signal sequence of n lanes that receive and parallel to the optical signals from the transmission optical module 30, respectively. And a separation unit 50 that recombines the second signal sequence from the reception optical module 40 in bit units in accordance with a separation rule based on the multiplexing rule and outputs a first signal sequence of m lanes in parallel. Receives a first signal sequence from the separation unit 50 includes a receiving unit 60 for restoring a frame signal from the block of the first signal sequence, a.

  FIG. 3 shows a configuration on the transmission side of the optical transmission system 301, which includes a transmission signal generation unit 10, an m: n multiplexing unit 20, and a transmission optical module 30.

  The transmission signal generation unit 10 generates a bit string (first signal string) to be transmitted from the input frame signal and outputs the bit string (first signal string) to the m: n multiplexing unit 20 through one or more lanes. The m: n multiplexing unit 20 multiplexes the m-lane first signal sequence to the n-lane bit sequence signal (second signal sequence). The multiplexing unit can be multiplexed as a single unit of bit units, byte units, tributary slot units, frame units, or an arbitrary number of bits. The multiplexed n-lane second signal sequence is output to the optical module 30 and modulated into an optical signal. The optical module 30 can select an arbitrary modulation method such as intensity modulation, phase modulation, or a combination thereof.

  FIG. 4 shows the configuration of the reception side of the optical transmission system 301, which includes the reception optical module 40, the n: m separation unit 50, and the reception unit 60.

  The reception optical module 40 converts the received optical signal into an electrical second signal sequence and outputs it to the n: m separation unit 50. Similarly to the transmission optical module 30, the reception optical module 40 can also receive a signal of intensity modulation, phase modulation, or a modulation scheme that combines them. The n: m separator 50 separates the second signal sequence into the first signal sequence of m lanes. The unit to be separated can be separated in bit units, byte units, tributary slot units, frame units, or arbitrary bit number units as in the transmission side. The first signal sequence separated into m lanes is restored to the original frame signal by the receiving unit 60 and subjected to signal processing.

  5 and 6 are diagrams showing a more detailed configuration of the m: n multiplexing unit 20. FIG. 5 shows an example in which the m: n multiplexing unit 20 has a plurality of circuits that do not perform reconfiguration such as ASIC (Application Specific Integrated Circuit) and selects any one of the circuits. The m: n multiplexing unit 20 in FIG. 5 switches the m lane input to switch to each multiplexing processing unit 22, and multiplexes the m lane input to 2, 4,..., P lane. A multiplex processing unit 22 to be performed, and a switch unit 23 that selects and outputs a signal output from the multiplex processing unit 22 are provided. The m: n multiplexing unit 20 in FIG. 5 prepares one or a plurality of multiplexing processing units 22 having a predetermined number of multiplexing, and switches the switching units (21 according to the number of lanes indicated by an external lane number switching signal. 23), the multiplex processing unit 22 is selected and multiplexed.

  FIG. 6 shows an example of a configuration in which the m: n multiplexing unit 20 has a reconfigurable circuit such as an FPGA (Field-Programmable Gate Array). The m: n multiplexing unit 20 in FIG. 6 includes an m: n multiple processing unit 26 and a multiple processing circuit storage unit 27. The multiprocessing storage unit 27 stores the circuit configuration of the m: n multiprocessing unit 26 for a predetermined number of multiplexing. The multiprocessing circuit storage unit 27 rewrites the circuit configuration of the m: n multiplexing processing unit 26 and performs m: n multiplexing with an external lane number switching signal as a trigger. Note that a general memory such as SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory) can be used for the multi-processing circuit storage unit 27.

  Although the configuration example of the m: n multiplexing unit 20 has been described with reference to FIGS. 5 and 6, the n: m separation unit 50 can be similarly configured using an ASIC, FPGA, or the like.

  FIG. 7 is a diagram illustrating an operation example on the transmission side when optical signals are transmitted in parallel in n lanes in the optical transmission system 301. The first signal sequence of m lanes generated from the transmission signal generator 10 is output to the transmission optical module 30 as a second signal sequence multiplexed in n lanes. At that time, the m: n multiplexing unit 20 does not use the output end to which the transmission optical module 30 is not connected as OFF. The m: n multiplexing unit 20 can be attached with a maximum of m transmission optical modules 30. When optical transmission is performed in n lanes, n transmission optical modules 30 are connected. The output terminals (mn) to which the transmission optical module 30 is not connected are open, and the second signal sequence is not output.

  In the optical transmission system 301, the operation example on the receiving side when transmitting optical signals in parallel in n lanes is the same. The optical signals in n lanes are received by n optical modules to form a second signal sequence, The n: m separation unit 50 separates this into a first signal sequence of m lanes.

(Embodiment 2)
8 and 9 are diagrams illustrating the configuration of the optical transmission system 302 according to the present embodiment. FIG. 8 shows a configuration on the transmission side, which includes a transmission signal generation unit 10, an m: n multiplexing unit 20, a transmission optical module 30, and a transmission side lane number identification unit 70. That is, the optical transmission system 302 detects the number of the transmission optical modules 30 in the optical transmission system 301 of FIG. 3, instructs the m: n multiplexing unit 20 about the lane number m and the lane number n, and generates a transmission signal. The transmission side lane number identifying unit 70 for instructing the unit 10 on the lane number m is further provided. By providing the transmission-side lane number identification unit 70, the optical transmission system 302 can determine the lane numbers m and n and automatically switch the multiplex numbers m and n.

  The transmission optical module 30 and the reception optical module 40 are standardized by a standard organization called MSA (Multi Source Agreement) such as SFF (Small Form Factor) and SFP (Small Form-Factor Pluggable). For this reason, the transmission-side lane number identifying unit 70 receives a predetermined signal such as MOD-DEF (module definition) or LOS (Loss of Signal) related to the optical module from the transmission optical module 30, thereby transmitting the optical module 30. The number of connections m, n can be determined according to the number of optical modules. Also for an optical module that does not support the above signals, the number of lanes m and n can be determined by identifying the presence or absence of connection from the potential difference at the output end of the m: n multiplexer 20. The transmission-side lane number identification unit 70 sends information on the lane numbers m and n determined from the identified number of optical modules to the transmission signal generation unit 10 and the m: n multiplexing unit 20 as lane number switching signals. The transmission signal generation unit 10 forms the first signal sequence so that the number of lanes is m based on the lane number switching signal. The m: n multiplexing unit 20 performs switching of the switches (21, 23) in FIG. 5 and switching of the multiplexing processing unit 26 in FIG. 6 based on the lane number switching signal.

  FIG. 9 shows a configuration on the reception side, which includes a reception optical module 40, an n: m separation unit 50, a reception unit 60, and a reception-side lane number identification unit 80. That is, the optical transmission system 302 detects the number of received optical modules 40 from the optical transmission system 301 in FIG. 4, instructs the n: m separation unit 50 about the lane number m and the lane number n, and receives the reception unit 60. Is further provided with a receiving side lane number identifying unit 80 for instructing the lane number m. By including the reception-side lane number identification unit 80, the optical transmission system 302 can determine the lane numbers m and n and automatically switch the multiplexing numbers m and n.

  Similarly to the transmitting side, the receiving side can determine the number n of optical modules using MOD-DEF and LOS signals, and can determine the number of lanes m and n according to the number of optical modules. The non-standardized optical module is the same as the transmission side, and the number n of optical modules can be determined from the input terminal potential difference of the n: m separator 50. The receiving-side lane number identifying unit 80 also sends the identified lane number m and n information to the n: m separating unit 50 and the receiving unit 60 as a lane number switching signal. The receiving unit 60 receives the first signal sequence having the number of lanes m based on the lane number switching signal. The n: m separation unit 50 performs switching of the switches (21, 23) in FIG. 5 and switching of the m: n multiplex processing unit 26 in FIG. 6 based on the lane number switching signal.

  In addition to the identification method, the reception-side lane number identifying unit 80 detects the power of the input optical signal, detects the method of switching the number of lanes m, or the band of the input or output optical signal, and sets the band. It is possible to switch to a corresponding lane number m.

(Embodiment 3)
10 and 11 are diagrams illustrating the configuration of the optical transmission system 303 according to the present embodiment. FIG. 10 shows a configuration on the reception side, which includes a reception optical module 40, a reception-side skew adjustment unit 90, an n: m separation unit 50, and a reception unit 60. That is, the optical transmission system 303 is arranged between the reception optical module 40 and the n: m separation unit 50 in the optical transmission system 301 of FIG. 4, and an optical signal is transmitted between the transmission optical module 30 and the reception optical module 40. Further, a reception-side skew adjustment unit 90 that adjusts the skew between the lanes generated in the second signal sequence is further provided.

  The received optical signal is converted into a second signal sequence by the reception optical module 40 and input to the reception-side skew adjustment unit 90. The reception-side skew adjustment unit 90 detects the head of the bit string based on the received marker of each lane, and compensates for the delay difference during optical transmission by buffering the second signal string according to the delay difference. The lane marker uses a predetermined bit pattern and can be arbitrarily determined such as 01010101... 00110011..., And the pattern is not limited to this. The transmission signal generation unit 10 periodically inserts lane markers. The period can be selected from either a frame unit or a bit unit, and is not limited to this. Note that the transmission side and the reception side need to set the cycle for inserting the lane marker and the bit pattern to be inserted in advance. The transmission signal generation unit 10 periodically inserts a pattern. However, if it is not necessary to change the pattern after setting at the time of activation, the pattern may be inserted only at the time of activation to set the delay of each lane.

  On the transmission side, a deskew channel for skew compensation can be provided between the transmission signal generation unit 10 and the m: n multiplexing unit 20 as necessary. FIG. 11 shows a configuration on the transmission side, which includes a transmission signal generation unit 10, an m: n multiplexing unit 20, a transmission side skew adjustment unit 100, and a transmission optical module 30. That is, the optical transmission system 303 is disposed between the m: n multiplexing unit 20 and the transmission optical module 30 in the optical transmission system 301 of FIG. 3, and an optical signal is transmitted between the transmission optical module 30 and the reception optical module 40. Is further provided with a transmission-side skew adjustment unit 100 that adjusts the skew between the lanes generated by the second signal sequence.

  The second signal sequence from the m: n multiplexing unit 20 is input to the transmission side skew adjustment unit 100. The transmission-side skew adjustment unit 100 is set with a delay difference that compensates for a skew generated in n columns of optical signals between the transmission optical module 30 and the reception optical module 40. The transmission-side skew adjustment unit 100 buffers the second signal sequence according to the delay difference and then outputs the second signal sequence to the transmission optical module 30. Therefore, the reception optical module 40 can receive an optical signal with compensated skew.

(Embodiment 4)
12 to 18 are diagrams illustrating specific operations of the transmission signal generation unit 10 and the multiplexing unit 20 of the optical transmission system (301 to 303). FIG. 12 is a diagram showing a configuration on the transmission side when OTL (Optical channel Transport Lane) is used, and m = 20. In the present embodiment, the frame signal input to the transmission signal generation unit 10 is an OTN frame.

  For example, when 100G OTN is transmitted in multilane, the transmission signal generator 10 and the multiplexer 20 are connected in 20 lanes. 20 lanes is the number of lanes in which the transmission signal is logically distributed, and the signal actually transmitted as an optical signal is a divisor of 20 lanes, an arbitrary number of lanes such as 10, 5, 5, 4, 2, 2 and 1 lane. It is possible to take The first signal sequence generated from the transmission signal generation unit 10 is output to the 20: n multiplexing unit 20 in 20 lanes. The multiplexing unit 20 multiplexes the first signal sequence into a second signal sequence of n lanes, and the n transmission optical modules 30 modulate each second signal sequence into an optical signal and send it out. The multiplexing unit 20 can set n to a divisor of 20 and sets unused output terminals (20-n) to OFF.

  Hereinafter, the operation of the transmission signal generation unit 10 will be described. When the transmission signal generation unit 10 distributes the block obtained by dividing the OTN frame to m lanes, the transmission signal generation unit 10 sets the distribution destination lane so that the distribution destination lane of the block is different from the distribution destination lane of the block at the same position of the immediately preceding frame signal. Rotate.

  An example of operation when transmitting in OTL 4.10 shown in FIG. 12 will be described. The transmission signal generation unit 10 generates an OTU4 frame and distributes it to the OTL 4.20 as shown in FIG. OTL 4.20 divides the OTN frame into 16-byte blocks and distributes these blocks to 20 lanes. When distributing a block to 20 lanes, lane rotation is performed for each frame. This will be specifically described with reference to FIG. In OTU4 frame # 1, the first block [1:16 (FAS)] is arranged in lane # 1, and the subsequent blocks are arranged in order in each lane. In the next OTU4 frame # 2, the first part lock [1:16 (FAS)] is arranged in the lane # 2, and the subsequent blocks are arranged in each lane in order. In this way, each block is arranged by rotating the lane every OTU4 frame.

  The OTU4 frame distributed to 20 lanes is multiplexed into 10 lanes by the multiplexing unit 20. FIG. 14 shows a generation method of OTL 4.10, in which a 20-lane first signal sequence is multiplexed in bit units according to a predetermined multiplexing rule. # 1 lane and # 2 lane are alternately multiplexed in bit units, # 3 lane and # 4 lanes are also alternately multiplexed in bit units, and the subsequent lanes are multiplexed in the same multiplexing rule. Generate OTL 4.10. The generated OTL 4.10 is converted from an electrical signal to an optical signal using ten transmission optical modules 30 and output.

  On the reception side, the reception optical module 40 receives the optical signal of 10 lanes to form a second signal sequence, and the separation unit 50 separates the first signal by a separation rule corresponding to the multiplexing rule performed by the multiplexing unit 20. Get a column. That is, the separation unit 50 alternately separates the first lane of the second signal sequence in bit units, and outputs the first lane to the # 1 lane and # 2 lane of the second signal sequence, and the second lane of the second signal sequence is a bit. The signals are alternately separated in units and output to the # 3 lane and # 4 lane of the second signal sequence, and the subsequent lanes are also separated according to the same separation rule. Further, the receiving unit 60 performs the reverse of the OTL 4.20 generation described with reference to FIG. 13 and restores the OTU4 frame.

  FIG. 15 is a diagram showing an operation example when transmitting in OTL 4.4. The transmission signal generation unit 10 generates an OTU4 frame, and outputs the OTL 4.20 signal distributed to 20 lanes to the multiplexing unit 20 as shown in FIG. The multiplexing unit 20 once generates an OTL 4.10 signal by bit multiplexing as a multiplexing rule, and then generates OTL 4.4 (second signal sequence) by bit multiplexing shown in FIG. 16 and outputs it to the transmission optical module 30. The transmission optical module 30 performs modulation based on the received second signal sequence and sends it to the reception side as an optical signal. In FIG. 15, as the multiplexing unit 20, one 20: 4 multiplexing unit is illustrated, but it may be configured by a plurality of multiplexing units in which 20:10 multiplexing and 10: 4 multiplexing are connected in series.

  FIG. 17 is a diagram illustrating an operation example when 40G OTU3 is used. The transmission signal generation unit 10 generates an OTU3 frame, distributes it to four lanes as shown in FIG. Similar to the OTU4 described with reference to FIG. 13, the OTU3 frame is divided into 16-byte blocks, and these blocks are distributed to the # 1 to # 4 lanes. After one frame is distributed, the block arrangement lane is rotated and the block is distributed again. In the case of OTU3, the rotation position is determined corresponding to the lower 2 bits of MFAS (Multi Frame Alignment Signal). Since the multiplexing unit 20 performs parallel transmission of four lanes, the first signal sequence is not multiplexed and is output to the transmission optical module 30 as a second signal sequence. The transmission optical module 30 modulates based on the received second signal sequence and transmits an optical signal.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and various modifications are possible within the scope of the gist of the present invention described in the claims.・ Change is possible.

  The following describes an adaptive electrical interface circuit composed of a transmission signal generation unit and a multiplexing unit on the transmission side of the optical transmission system of the present embodiment, and an adaptive electrical interface circuit composed of a separation unit and a reception unit on the reception side. .

(1)
An adaptive electrical interface circuit that multiplexes and separates frame signals into multiple lanes,
A transmission signal generator for generating a transmission signal;
An m: n multiplexing unit that multiplexes an arbitrary m-lane signal into an arbitrary n-lane signal;
An n: m separator that separates the signals of the arbitrary n lanes into the arbitrary m lanes;
A receiving unit that performs reception processing of the signals of the separated m lanes;
An adaptive electrical interface circuit comprising:

(2)
The adaptive electrical interface circuit according to (1), further comprising a skew adjustment unit that compensates for a skew generated in each lane before the separation unit.

(3)
A transmission signal generation unit for transmitting an OTL frame distributed to multiple lanes after generating an OTU frame;
A multiplexing unit for detecting a lane marker of the OTL frame and multiplexing the lane marker to a desired number m of lanes;
A separator that separates the OTL frame multiplexed into the m lanes into n lanes;
A receiving unit for restoring an OTU frame from the separated OTL frame;
The adaptive electrical interface circuit according to (1), further comprising:

10: transmission signal generation unit 20: multiplexing unit 21, 23: switch unit 22: multiplexing processing unit 26: multiplexing processing unit 27: multiplexing processing circuit storage unit 30: transmission optical module 40: reception optical module 50: separation unit 60: reception Unit 70: Transmission-side lane number identification unit 80: Reception-side lane number identification unit 90: Reception-side skew adjustment unit 100: Transmission-side skew adjustment units 301, 302, and 303: Optical transmission system

Claims (8)

A transmission signal generator that divides a frame signal to be transmitted into a plurality of blocks, distributes the blocks to m (m is an integer equal to or greater than 1) lanes, and outputs a first signal sequence;
The first signal sequence from the transmission signal generation unit is time-multiplexed in units of bits according to a predetermined multiplexing rule, and reassembled into a second signal sequence in parallel in n (n is m ≧ n, a divisor of m) lanes. A multiplexing section;
A transmission optical module that converts each of the second signal sequences from the multiplexing unit into an optical signal;
A receiving optical module that receives each of the optical signals from the transmitting optical module and outputs the second signal train of n lanes in parallel;
A demultiplexer configured to reassemble the second signal sequence from the reception optical module in units of bits according to a demultiplexing rule based on the multiplexing rule, and to output the first signal sequence of m lanes in parallel;
A receiver that receives the first signal sequence from the separation unit and restores the frame signal from the block of the first signal sequence;
An optical transmission system comprising :
The multiplexing unit changes the multiplexing rule according to an external signal, the parallel number of the second signal sequence is variable,
The separation unit changes the separation rule according to an external signal, and makes the parallel number of the second signal sequence variable.
An optical transmission system characterized by that .   When transmitting the block to m lanes, the transmission signal generation unit rotates the distribution destination lane so that the distribution destination lane of the block is different from the distribution destination lane of the block at the same position of the immediately preceding frame signal. The optical transmission system according to claim 1. A lane that detects at least one of the transmission optical module and the reception optical module and instructs the transmission signal generation unit, the multiplexing unit, the separation unit, and the reception unit to specify the number of lanes m and the number of lanes n. The optical transmission system according to claim 1, further comprising an identification unit.   4. The skew adjusting unit according to claim 1, further comprising a skew adjusting unit that adjusts a skew between lanes generated in the optical signal between the transmitting optical module and the receiving optical module by the second signal sequence. The optical transmission system according to any one of the above. A transmission signal generation procedure for dividing a frame signal to be transmitted into a plurality of blocks, distributing the blocks to m (m is an integer of 1 or more) lanes, and outputting a first signal sequence;
The first signal sequence in the transmission signal generation procedure is time-multiplexed in units of bits according to a predetermined multiplexing rule, and reassembled into a second signal sequence in parallel in n (n is m ≧ n, a divisor of m) lanes. Multiple procedures,
An optical signal transmission procedure for converting each of the second signal sequences in the multiplexing procedure into an optical signal;
A light receiving procedure for receiving each of the optical signals of the optical signal transmitting procedure and outputting the second signal sequence of n lanes in parallel;
A separation procedure for reassembling the second signal sequence in the light receiving procedure in units of bits according to a separation rule based on the multiplexing rule, and outputting the first signal sequence of m lanes in parallel;
Receiving the first signal sequence in the separation procedure, and restoring the frame signal from the block of the first signal sequence;
An optical transmission method of performing,
In the multiplexing procedure, the multiplexing rule is changed by an external signal, the parallel number of the second signal sequence is variable,
In the separation procedure, the separation rule is changed by an external signal, and the parallel number of the second signal sequence is variable.
An optical transmission method characterized by the above .
  In the transmission signal generation procedure, when distributing the block to m lanes, the distribution destination lane is rotated so that the distribution destination lane of the block is different from the distribution destination lane of the block at the same position of the immediately preceding frame signal. The optical transmission method according to claim 5, wherein:   A lane identification procedure for detecting at least one of the transmission optical module and the reception optical module, and determining the number of lanes m and the number of lanes n in the transmission signal generation procedure, the multiplexing procedure, the separation procedure, and the reception procedure. The optical transmission method according to claim 5 or 6, further executed.   8. The optical transmission method according to claim 5, further comprising executing a skew adjustment procedure for adjusting a skew between lanes generated in the optical signal by the second signal sequence.

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