JP5299558B2 - Optical communication apparatus, optical communication system, optical signal control method, and program - Google Patents

Abstract

There are included a transmission path length measurement signal generating unit (120) for generating, as transmission path length measurement signals, a plurality of pulse signals having different frequencies; an optical signal transmitting/receiving unit (110) for transmitting/receiving optical signals including the transmission path length measurement signals; an amplitude information extracting unit (130) for extracting the amplitude information of the plurality of pulse signals included in the transmission path length measurement signals; a transmission path length deriving unit (140) for deriving, from the amplitude information, the distance of an optical transmission path; and an optical signal output control unit (150) for controlling, based on the transmission path length, the transmission output of the optical signals. Even for an optical transmission path of a short distance, the transmission path length is measured and an optimization of the transmission output is executed in accordance with the characteristic of the transmission path, whereby the degradation of communication quality caused by the mode dispersion of optical signals can be suppressed.

Description

The present invention relates to an optical communication apparatus, an optical communication system , an optical signal control method, and a program , and in particular, an optical communication apparatus, an optical communication system , and an optical signal control in inter-housing communication such as an information processing apparatus configured by a computer system or the like. It relates to a method and a program .

In recent years, performance required for an information processing apparatus constituted by a computer system or the like has been dramatically improved.
As an example of a computer system, there is a computer system such as a blade server in which a plurality of CPU (Central Processing Unit) cards are mounted in a casing and perform cooperative processing. A configuration of a general blade server is shown in FIG. As shown in FIG. 6, the CPU card is a CPU unit that performs arithmetic processing and instruction processing, a north bridge unit for connecting a device having a high-speed bus such as a memory unit and the CPU unit, and an I / O via the north bridge unit. A south bridge unit for connecting a device having a low-speed bus such as the O unit and the CPU unit.

The switch card for connecting the CPU cards includes an I / O unit that receives data from the CPU card, a route table unit that stores information about which switch port the desired CPU card is connected to, and I The switch unit is connected to the / O unit and performs port connection with reference to the route table unit, and the connection between the CPU cards is realized via the switch card.
Details of the I / O unit are shown in FIG. As shown in FIG. 7, the I / O unit receives data from the south bridge side, and converts it into a bit string suitable for a transmission medium such as a protocol processing unit, a transmission / reception unit, or a transmission path that performs data transmission arrangements. The transmission / reception unit is an interface with a physical layer unit and a transmission path. Here, with regard to the communication protocol, for example, PCI-Express (Peripheral Component Interconnect-Express) widely used for communication between CPUs and Ethernet (registered trademark) widely used for data transmission within or between cases. )

As the amount of data transmitted between cases such as a CPU card built in a computer system increases with the performance enhancement of information processing apparatuses in recent years, the use of optical communication is progressing as data transmission between cases. As an example, when a distance of about 100 m is required for transmission between cases, data transmission between cases is executed using optical communication for data transmission between cases.
In addition, in communication within a housing such as PCI-Express, since the communication distance, that is, the data transmission distance is a short distance of about 1 m, electrical transmission is currently mainstream. However, when the data transmission rate is higher (the transmission rate is assumed to be 5 Gbps and 8 Gbps in the future), it is assumed that data transmission using light capable of larger capacity communication is used.

  In a computer system that performs large-capacity data transmission as described above, the power consumption of the entire system increases due to the increase in power consumption by using a high-performance CPU and the increase in power consumed to realize high-speed data communication. The increase in power consumption of computer systems that realize large-capacity data processing and data transmission is a problem.

In order to solve such problems, it is important to control the power consumption related to information processing (arithmetic processing, instruction processing, etc.) and the power consumption related to data transmission, and the respective power consumption is actively researched. Development is underway.
For example, to reduce the power consumption of information processing, research and development of technology that suppresses the amount of heat generated without causing performance degradation by linking a plurality of CPUs with lower clock numbers is underway.
As for the reduction in power consumption of data transmission, research and development for reducing power consumption at the protocol level has been conducted. For example, a technology for controlling the voltage of a transmission line according to the amount of data for PCI-Express, etc. It is known (Non-Patent Document 1).

Regarding power saving of data transmission in optical communication, Patent Documents 1 to 5 are known as methods of power saving of a transmission unit in optical communication.
Here, FIG. 16 is a diagram conceptually illustrating the operation principle of the technique described in Patent Document 1. In FIG. The technique described in Patent Document 1 stores in advance the power of the signal transmitted from the node A 81 received by the node B 82 when optical communication between the master station (node A) 81 and the slave station (node B) 82 is executed. The loss in the transmission path is calculated by comparing with the transmission signal power of the node A81, and the transmission power is adjusted according to the transmission path length based on the calculated loss.

  FIG. 17 conceptually illustrates the operation principle of the technique described in Patent Document 2. In the technique described in Patent Document 2, when optical communication between the node A 91 and the node B 92 is executed, the node B 92 receives the signal transmitted from the node A 91 and detects the received signal power, and the detected received signal power is detected. By notifying the node A91, the transmission power of the node A91 is adjusted so that the received signal power is optimal at the node B92.

The technique described in Patent Document 3 estimates the transmission path length between the master station and the slave station based on the transmission delay time generated between the master station and the slave station in the optical communication system. Accordingly, the transmission power of the slave station is adjusted accordingly.
The technique described in Patent Document 4 measures the distance between nodes using a measurement signal for measuring the distance between the nodes and calculates the transmission loss, and calculates the measured distance and the calculated transmission loss. Based on this, the transmission signal power is determined.
The technique described in Patent Document 5 measures the time required for the pulse signal transmitted from the measurement source node to be received by the transmission source node after reciprocating the distance to the measurement target node. It is executed multiple times to improve measurement accuracy.

Japanese Patent Laid-Open No. 08-274719 JP-A-11-234209 Japanese Patent Laid-Open No. 11-068707 JP 2008-054444 A JP-A-10-153660

PCI-Express Base Specification Revision 1.x pp.231 ~ 272

  However, all of the techniques related to the present invention as described above are techniques for optimizing the optical output of the transmission signal in consideration of the transmission loss caused by the transmission path length between the nodes. This is not a technique for optimizing the optical output of a transmission signal in consideration of transmission loss caused by mode dispersion of the optical signal. That is, when the transmission path length is a short distance of about several tens of centimeters such that the transmission loss caused by the transmission path length is small but the transmission loss due to the mode dispersion of the optical signal generated between the transmission paths occurs. The technology related to the problem that the transmission signal output cannot be optimized.

Specifically, for example, in the technique related to the present invention using the time required for the pulse signal transmitted from the measurement source to be received at the transmission source by reciprocating the transmission path to the target, the multi-mode laser beam is used. When the transmission path length is about several tens of centimeters in short-distance optical communication, the round trip time of the pulse signal is less than or equal to the clock frequency of the apparatus, so that the transmission path length cannot be measured.
Furthermore, in short-distance optical communication using multimode laser light with a transmission path length of about 100 meters, such as a computer system such as a blade server, transmission loss (power loss) of a transmission signal due to the transmission path length. ) Is insignificant (about 1 dB), and the influence on the deterioration of the transmission signal is not significant. On the other hand, mode dispersion caused by the difference in transmission speed of each mode of multimode laser light generated according to the characteristics of the optical fiber used in the transmission path causes the waveform distortion in the time axis direction to occur in the transmission signal. Will lead to deterioration of communication quality.

Therefore, the technique related to the present invention that compensates for transmission loss of the transmission signal due to the transmission path length cannot measure the transmission path length over a short distance in optical communication, and therefore the transmission signal output is not optimized. However, it was not possible to prevent deterioration in communication quality due to optical signal mode dispersion.
Therefore, in order to solve the above-mentioned problems, the present invention measures the length of a transmission line even in a transmission line over a short distance, optimizes the transmission signal output according to the characteristic of the transmission line, and performs an optical signal mode. An object of the present invention is to provide an optical communication apparatus that suppresses deterioration of communication quality due to dispersion.

  In order to achieve the above object, an optical communication apparatus according to the present invention includes an optical signal transmitting / receiving unit that transmits and receives an optical signal to and from a communication partner via an optical signal transmission path, and a plurality of pulse signals having different frequencies. And a transmission path length measurement signal generator that outputs the transmission path length measurement signal to the optical signal transmitter / receiver, and is transmitted from the communication partner and received by the optical signal transmitter / receiver. When an optical signal includes a transmission path length measurement signal, an amplitude information extraction unit that extracts amplitude information of each of the plurality of pulse signals included in the transmission path length measurement signal and a distance between the optical signal transmission path Transmission path length information representing the relationship between the amplitude and frequency of the received signal, and amplitude information corresponding to each frequency of the plurality of pulse signals extracted by the amplitude information extraction unit, and the transmission path length information, In Therefore, a transmission path length deriving unit for deriving the distance of the optical signal transmission path, and a transmission output of the optical signal transmitting / receiving unit according to the transmission path type and the transmission path length distinguished by the frequency band of the transmittable optical signal The optical signal output control information is stored, and is based on the distance of the optical signal transmission path derived by the transmission path length deriving unit, the transmission path type of the optical signal transmission path, and the optical signal output control information And an optical signal output control unit that controls a transmission output of an optical signal transmitted from the optical signal transmission / reception unit.

  The optical communication control method according to the present invention includes a step of generating a plurality of pulse signals having different frequencies as a transmission path length measurement signal, and an optical signal including the transmission path length measurement signal via the optical signal transmission path. Transmitting to the communication partner, and if the received optical signal includes the transmission path length measurement signal, extracting each of amplitude information of the plurality of pulse signals included in the transmission path length measurement signal; and A step of deriving the distance of the optical signal transmission path based on the transmission path length information indicating the relationship between the amplitude and frequency of the received signal according to the distance of the optical signal transmission path, and the amplitude information; Optical signal output control information indicating the relationship of the transmission output of the optical signal output to the optical signal transmission path according to the transmission path type and the distance of the optical signal transmission path distinguished by the frequency band of the signal, and The step of determining the transmission output of the optical signal based on the distance of the signal transmission path and the transmission path type of the optical signal transmission path, and the transmission output of the optical signal output to the optical signal transmission path, And a step of controlling to a transmission output determined based on the optical signal output control information, the rejection of the optical signal transmission path, and the transmission path type.

  The optical communication system according to the present invention includes a plurality of optical communication devices connected via at least one optical signal transmission path, and each of the plurality of optical communication devices communicates with a communication partner. An optical signal transmission / reception unit that transmits / receives an optical signal via a transmission line and a transmission line length measurement signal including a plurality of pulse signals having different frequencies are generated, and the transmission line length measurement signal is output to the optical signal transmission / reception unit When the transmission path length measurement signal is included in the transmission path length measurement signal generation unit and the optical signal transmitted from the communication partner and received by the optical signal transmission / reception unit, the plurality of the transmission path length measurement signals included in the transmission path length measurement signal An amplitude information extraction unit that extracts amplitude information of each pulse signal, and transmission path length information that represents a relationship between the amplitude and frequency of the received signal according to the distance of the optical signal transmission path, and stores the amplitude information A transmission path length deriving unit for deriving a distance of the optical signal transmission path based on amplitude information corresponding to each frequency of the plurality of pulse signals extracted and the transmission path length information; and Storing optical signal output control information indicating a transmission output of the optical signal transmission / reception unit according to a transmission path type and a transmission path length distinguished by a frequency band, and the optical signal transmission derived by the transmission path length deriving unit An optical signal output control unit configured to control a transmission output of an optical signal transmitted from the optical signal transmission / reception unit based on a path distance, the transmission path type of the optical signal transmission path, and the optical signal output control information. It is characterized by that.

  According to the present invention, the transmission path length is measured based on the amplitude information of the transmission path length measurement signals having different frequencies, and the transmission output of the optical signal is controlled based on the measured transmission path length and the transmission path characteristics. In addition, the transmission output of the optical signal can be optimized even in the transmission path between short distances. Therefore, in optical communication over short distances where transmission loss due to optical signal mode dispersion occurring between transmission lines is more dominant than transmission loss caused by transmission line length, communication quality due to optical signal mode dispersion is reduced. Deterioration can be suppressed.

FIG. 1 is a block diagram showing the configuration of the optical communication apparatus according to the first embodiment of the present invention. FIG. 2 is a flowchart illustrating the operation of the optical communication apparatus according to the first embodiment. FIG. 3 is a diagram showing an outline of a large-capacity optical communication system including the optical communication apparatus according to the second embodiment of the present invention. FIG. 4 is a diagram illustrating a cross-section of the large-capacity optical communication system in the second embodiment. FIG. 5 is a diagram illustrating the configuration of the backplane of the large-capacity optical communication system in the second embodiment. FIG. 6 is a functional block diagram of the large-capacity optical communication system including the optical communication apparatus according to the second embodiment. FIG. 7 is a diagram illustrating a configuration of an I / O unit of an optical communication system in a large-capacity housing that includes the optical communication apparatus according to the second embodiment. FIG. 8 is a diagram illustrating an example of a connection topology between cards of an optical communication system in a large-capacity housing that includes the optical communication apparatus according to the second embodiment. FIG. 9 is a diagram illustrating an example of a connection topology between cards in an optical communication system within a large-capacity housing including the optical communication apparatus according to the second embodiment. FIG. 10 is a block diagram of the configuration of the optical communication apparatus according to the second embodiment. FIG. 11 is a block diagram illustrating an optical communication system in which the optical communication apparatus according to the second embodiment is configured as a transmission node and a reception node. FIG. 12 is a diagram conceptually illustrating a waveform of a pulse signal received by the optical signal transmission / reception unit of the optical communication apparatus according to the second embodiment. FIG. 13 is a diagram for conceptually explaining the transmission path length information in the second embodiment. FIG. 14 is a flowchart illustrating the operation of the optical communication apparatus according to the second embodiment. FIG. 15 is a block diagram showing a configuration of an optical communication apparatus according to the third embodiment of the present invention. FIG. 16 is a block diagram showing a configuration of an optical communication system in the technology related to the present invention. FIG. 17 is a block diagram showing a configuration of an optical communication system in the technology related to the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the optical communication apparatus according to the first embodiment of the present invention. The optical communication apparatus according to the present embodiment measures the transmission path length from amplitude information of a plurality of received pulse signals having different frequencies, and controls the transmission output of the optical signal based on the measured transmission path length. is there.

As shown in FIG. 1, the optical communication apparatus 10 according to the present embodiment includes an optical signal transmission / reception unit 110, a transmission path length measurement signal generation unit 120, an amplitude information extraction unit 130, and a transmission path length derivation unit 140. , And an optical signal output control unit 150.
The optical signal transmission / reception unit 110 performs transmission / reception of an optical signal via the optical signal transmission path A with an optical communication apparatus that is a communication partner.
The transmission path length measurement signal generation unit 120 generates at least two pulse signals having different frequencies as transmission path length measurement signals, and causes the optical signal transmission / reception unit 110 to transmit the transmission path length measurement signals. The transmission path length measurement signal may be three or more pulse signals having different frequencies.

When the transmission path length measurement signal is included in the optical signal received via the optical signal transmission / reception section 110, the amplitude information extraction unit 130 extracts the amplitude information of the pulse signal included in the received transmission path length measurement signal for each frequency. To do.
The transmission path length deriving unit 140 stores transmission path length information representing the relationship between the amplitude and frequency of the received pulse signal according to the distance of the optical signal transmission path, and the pulse signal extracted by the amplitude information extracting unit 130 The distance of the optical signal transmission line is derived on the basis of the amplitude information corresponding to each week number and the transmission line length information.

  The optical signal output control unit 150 stores the transmission output of the optical signal transmitted from the optical signal transmission / reception unit 110 according to the transmission path length and the transmission path type distinguished for each frequency band of the transmittable optical signal. Stores the signal output control information, and determines the transmission output of the optical signal transmitted from the optical signal transmission / reception unit 110 based on the distance of the optical signal transmission path derived by the transmission path length deriving unit 140 and the optical signal output control information To do.

Each function of the optical communication apparatus 10 according to the present embodiment is that a computer program (software) is installed in a computer having a CPU (central processing unit), a memory, and an interface mounted on the optical communication apparatus 10. The various functions of the optical communication apparatus 10 described above are realized by the cooperation of various hardware resources of the computer and the computer program.
The computer program may be provided in a state of being stored in a computer-readable recording medium, or may be provided in a state of being readable by the computer via an electric communication line.

Next, the operation of the optical communication apparatus 10 according to the present embodiment will be described with reference to the flowchart shown in FIG.
As shown in FIG. 2, the optical communication apparatus 10 according to the present embodiment generates a transmission path length measurement signal including a plurality of pulse signals of different frequencies by the transmission path length measurement signal generator 120, and this transmission path The length measurement signal is transmitted to the optical signal transmission / reception unit 110 (step S101).

The optical communication device 10 determines whether the optical signal received via the optical signal transmission path A is a transmission path length measurement signal (step S102).
When the received optical signal is a transmission path length measurement signal (“Yes” in step S102), the amplitude information extraction unit 130 performs amplitude information corresponding to each frequency of the pulse signal included in the received transmission path length measurement signal. And the optical signal including the amplitude information is transmitted to the optical signal transmitting / receiving unit 110 (step S103).
On the other hand, when the received optical signal is not a transmission path length measurement signal (“No” in step S102), the optical communication device 10 includes the amplitude information extracted by the amplitude information extraction unit 130 in the received optical signal. It is determined whether or not (S step 104).

When amplitude information is not included in the received optical signal (“No” in step S104), the optical communication apparatus 10 is in a standby state for determining whether or not a transmission path length measurement signal is included in the received optical signal. (S step 102).
On the other hand, when amplitude information is included in the received optical signal (“Yes” in S104), the transmission path length deriving unit 140 stores the amplitude information included in the received optical signal and the transmission path stored in advance. Based on the length information, the transmission path length of the optical signal is derived (S step 105).
When the transmission path length of the optical signal is derived by the transmission path length deriving unit 140, the optical signal output control unit transmits the optical signal output control information stored in advance and the transmission path length derived by the transmission path length deriving unit 140. Based on the above, the transmission output of the optical signal output from the optical signal transmission / reception unit 110 is determined to control the transmission output of the optical signal (S step 106).

  Thus, according to the optical communication apparatus according to the present embodiment, the transmission path length is measured based on the amplitude information of the transmission path length measurement signals having different frequencies, and based on the measured transmission path length and transmission path characteristics. By controlling the transmission output of the optical signal, the transmission output of the optical signal can be optimized even in a transmission path over a short distance.

[Second Embodiment]
The optical communication apparatus according to the second embodiment of the present invention measures a transmission path length from amplitude information of a plurality of received pulse signals having different frequencies, and based on the measured transmission path length and transmission path type. In particular, it is installed in a computer system in which a plurality of CPU cards are mounted in a casing and information processing such as data transmission and arithmetic processing is performed in cooperation between these CPU cards. The optical communication device controls the transmission output of the optical signal based on the transmission path length between the CPU cards and the type of the transmission path.

FIG. 3 is an overall view of a computer system 1 including the optical communication apparatus according to the present embodiment. This computer system includes a plurality of CPU cards 2 and at least one switch card 3 in a housing 1. It is configured by being mounted.
In the case of data transmission within the housing of the computer system in the present embodiment, optical communication is performed for large-capacity and high-speed main signal data transfer executed between the CPU card 2 and the switch card 3, and low-speed / Telecommunications can be used for small capacity data transmission. Hereinafter, the optical communication used for the main signal data transfer described above in the data transmission within the case of the computer system according to the present embodiment is referred to as “large-capacity case optical communication”, and this large-capacity case optical communication is realized. Is represented as “a large capacity optical communication system”.

Next, with reference to FIG. 4 and FIG. 5, the internal structure of the casing 1 of the computer system according to the present embodiment will be described.
FIG. 4 is a cross-sectional view of the housing 1. At least one optical connector 4-11, power connector 4-21, and electrical connector 4-23 are mounted on the CPU card 2 and the switch card 3.
An optical backplane 4-1 and an electrical backplane 4-2 are mounted on the housing 1, and at least one optical connector 4-12 is provided on the optical backplane 4-1. 11 is mounted so as to face 11. Similarly, at least one power connector 4-22 and electrical connector 4-24 are mounted on the electrical backplane 4-2 so as to face the power connector 4-21 and the electrical connector 4-23.

In the computer system according to the present embodiment, when the CPU card 2 and the switch card 3 are inserted into the housing 1, the optical connectors 4-11 and 4-12, the power connectors 4-21 and 4-22, the electrical connector 4- 23 and 4-24 are fitted. The optical connection between the cards is made by an optical fiber 4-13 connected to an optical connector 4-12 mounted on the optical backplane 4-1, and optical communication is performed via the optical fiber 4-13. Is done. Note that pattern wiring (not shown) is mounted on the electric backplane 4-2, and electrical wiring between cards is realized along this pattern.
FIG. 5 shows a view of the optical backplane 4-1 and the electrical backplane 4-2 as seen from the front. The CPU card 2 is inserted into the CPU card slot 5-1, and the switch card 3 is inserted into the switch card slot 5-2, so that the optical connectors 4-11 and 4-12, the power connectors 4-21 and 4-22, The electrical connectors 4-23 and 4-24 are engaged with each other.

Next, the configuration of the optical communication system with large capacity in this embodiment will be described with reference to FIG.
As shown in FIG. 6, the large-capacity communication system in the present embodiment has a configuration in which a CPU card 2 and a switch card 3 are mounted in a housing 1.
A plurality of CPU cards 2 (hereinafter referred to as “CPU card 2-1n” for the sake of convenience) include a CPU unit 611 that performs arithmetic processing and instruction processing, a memory unit 612 that stores data and programs, and a high-speed data bus. A north bridge unit 613 that connects a device that transmits and receives data and the CPU unit 611, an I / O unit 614 that is an interface with an external card such as the switch card 3, and the CPU unit 611 via the north bridge unit 613 A south bridge unit 615 that connects the I / O unit 614 is configured.
The switch card 3 includes an I / O unit 621 that is an interface with the CPU card 2-1n, a route table unit 622 that stores a port to which each of the CPU cards 2-1n is connected, and manages the information as route information. The switch unit 623 selectively connects a desired CPU card with reference to the path information.

Here, the I / O units 614 and 621 which are interfaces for data transmission executed between the CPU card 2-1n and the switch card 3 are illustrated by taking the I / O unit 614 of the CPU card 2-1n as an example. This will be described with reference to FIG.
The I / O unit 614 includes a protocol processing unit 71 that converts a signal to be transmitted into a desired transmission format, a physical layer unit 72 that encodes the signal to be transmitted and converts it into a bit string signal suitable for the transmission medium, The optical transmission unit 73 and the optical reception unit 74 are interfaces with the communication transmission path.
For example, when data transmission is performed from the CPU card 2 to the switch card 3, the I / O unit 614 receives a signal received from the south bridge unit 615 by the protocol processing unit 71 in a desired transmission format (for example, Ethernet or PCI). -A transmission format adapted to a data transmission method such as Express), and the transmission signal is encoded by the physical layer unit 72 (in Ethernet, encoding means such as 8B / 10B and 64B / 66B are known) A bit string signal suitable for the transmission medium is generated, and an optical signal corresponding to the bit string signal is output to the optical communication transmission path by the optical transmitter 73.

In a computer system such as a blade server, the connection between the CPU card 2-1n and the switch card 3 is generally connected in a star topology, and in this case, a transmission path for data transmission between a plurality of CPU cards 2-1n The transmission path for data reception is symmetrical and the transmission distance is the same. FIG. 8 shows a general connection topology between a CPU card and a switch card.
On the other hand, in the case of a large-capacity optical communication system composed of a plurality of CPU cards 2-1n and a plurality of switch cards 3, a transmission path for data transmission / reception between the plurality of CPU cards 2-1n includes a plurality of switch cards 3. Therefore, the transmission path may be asymmetric in transmission and reception, and there may be a difference in transmission distance. FIG. 9 shows an example of a connection topology between the CPU card 2-nn and the switch card 3-n when a network is configured by a plurality of switch cards 3 in the optical communication system with a large capacity.

  For example, as shown in FIG. 9, when data transmission is executed between the CPU card 2-1n and the CPU card 2-3n, data transmitted from the CPU card 2-1n to the CPU card 2-3n is transmitted. The path is transmitted from the switch card 3-a to the CPU card 2-3n via the switch card 3-b and the switch card 3-n, but transmitted from the CPU card 2-3n and received by the CPU card 2-1n. Since the data transmission path to be transmitted passes from the switch card 3-n to the switch card 3-c and the switch card 3-a, there is a possibility that the transmission / reception transmission path becomes asymmetric and the transmission path length varies.

As described above, in a large-capacity optical communication system, when a transmission / reception transmission path becomes asymmetric and a difference occurs in the transmission / reception transmission path length, a transmission signal resulting from mode dispersion of a multimode laser beam used as a light source for optical communication Variations in the degradation of the network will lead to degradation of communication quality. Therefore, measuring the transmission path length of the optical communication transmission path between each card and performing transmission control of the optical signal according to the transmission path length improves the communication quality in the data transmission of the optical communication system in the large capacity enclosure. Is required.
Therefore, the optical communication apparatus according to the present embodiment is mounted on the I / O units 614 and 621 that are interfaces between the CPU card 2-1n and the switch card 3 mounted in the large-capacity optical communication system. By measuring the transmission path length between cards and performing transmission control of an optical signal according to the transmission path length, the communication quality in data transmission of an optical communication system in a large-capacity housing is improved.

FIG. 10 is a block diagram showing the configuration of the optical communication apparatus 20 according to the present embodiment. In addition, about the component of the optical communication apparatus 20 concerning this Embodiment, what has the same structure and function as the optical communication apparatus 10 demonstrated in 1st Embodiment attaches | subjects the same code | symbol, and the detail Description is omitted.
The optical communication apparatus 20 according to the present embodiment includes an optical signal transmission / reception unit 210, a transmission path length measurement signal generation unit 120, an amplitude information extraction unit 130, a transmission path length derivation unit 240, and an optical signal output control unit 250. It consists of and.

The optical signal transmission / reception unit 210 generates an optical transmission unit 211 that transmits an optical signal, an optical reception unit 212 that receives an optical signal, and a transmission signal that is transmitted from the optical transmission unit 211 and transmission received by the optical reception unit 212. And a physical layer unit 213 for restoring a communication packet included in the signal.
The optical transmission unit 211 includes a laser element unit (hereinafter referred to as “LD”) 211-1 that emits multimode laser light, and an LD driver (hereinafter referred to as “LDD”) that drives the LD 211-1. The optical receiving unit 212 may include an optical receiving element unit (hereinafter referred to as “PD”) 212-1 that converts an optical signal into a current signal, and a PD 212-1. It is good also as a structure which consists of the amplifier 212-2 which converts the output electric current signal into a voltage signal. Further, the amplifying unit 212-2 can be realized by using a transimpedance amplifier that converts a current signal into a voltage signal and a limiting amplifier that forms a waveform for the output from the transimpedance amplifier. Hereinafter, the amplification unit 212-2 is expressed as LA / TIA 212-2.

The transmission path length measurement signal generation unit 120 generates at least two pulse signals having different frequencies as transmission path length measurement signals, and outputs the generated transmission path length measurement signals to the physical layer unit 213.
The amplitude information extraction unit 130, when the transmission path length measurement signal is included in the received signal restored to the communication packet by the physical layer unit 213, the amplitude information of the transmission path length measurement signal (a plurality of pulse signals having different frequencies). And the extracted amplitude information is output to the physical layer unit 213.
When the amplitude information is included in the received signal restored to the communication packet by the physical layer unit 213, the transmission path length deriving unit 240 determines the transmission path length from the received amplitude information and the previously stored transmission path length information. Is derived.

The optical signal output control unit 250 includes an optical signal output control table 251 for storing optical signal output control information, and the transmission level derived by the transmission path length deriving unit 240 in which the output level of the optical signal transmitted from the optical transmission unit 211 is derived. The output level of the optical signal transmitted from the optical transmitter 211 is determined from the path length and the optical signal output control information stored in advance, and control is performed so that the optical signal is output with the determined output.
The optical signal output control information is transmitted from the optical transmission unit 211 corresponding to the transmission distance in the optical signal transmission path and the type of the optical signal transmission path (for example, the type of optical fiber corresponding to the frequency band that can be transmitted). This is data in which output information of the optical signal is stored. An example of the optical signal output control table 251 in which optical signal output control information is stored is shown in Table 1 below.

Here, the transmission path length derivation function by the transmission path length derivation 240 and the optical signal transmission output control function by the optical signal output control unit 250 of the optical communication apparatus 20 according to the present embodiment will be described with reference to FIGS. This will be described in detail with reference to FIG.
FIG. 11 shows a case where a CPU card 2-1n and a switch card 3-a are connected, for example, as shown in FIG. It is a block diagram which shows an example of a structure of each card | curd.

As shown in FIG. 11, the CPU card 2-1n is an optical communication device (hereinafter, simply referred to as “master node”) 20-a serving as a transmission path length measurement master node, and the switch card 3-a is a transmission path length. The optical communication device (hereinafter simply referred to as “measurement target node”) 20-b, which is a measurement target node, is connected to the master node 20-a and the measurement target node 20-b via the optical signal transmission line A. Has been.
The master node 20-a causes the transmission path length measurement signal generation unit 120-a to generate a transmission path length measurement signal in order to measure the distance of the optical signal transmission path A to the measurement target node 20-b. A transmission path length measurement signal is transmitted from the optical transmitter 211-a. For example, the transmission path length measurement signal generation unit 120-a transmits a 0/1 rectangular wave (first pulse signal) having a frequency of 50 MHz and a 0/1 rectangular wave (second pulse signal) having a frequency of 5 GHz. When generating as a path length measurement signal, the first pulse signal and the second pulse signal are output to the physical layer unit 213-a.

  The physical layer unit 213-a encodes and converts the transmission path length measurement signal including the first pulse signal and the second pulse signal output from the transmission path length measurement signal generation unit 120-a and converts the bit string. The LDD 211-2a drives the LD 211-1a to output an optical signal corresponding to the transmission path length measurement signal to the optical signal transmission path A.

When the optical transmission / reception unit 210-b of the measurement target node 20-b receives the optical signal corresponding to the transmission path length measurement signal transmitted from the master node 20-a via the optical signal transmission path A, the received optical signal is The current signal is converted into a current signal by the PD 212-1b of the optical receiving unit 212-b, and the current signal is converted into a voltage signal by the LA / TIA 212-2b and output to the amplitude information extracting unit 130-b.
The amplitude information extraction unit 130-b obtains the voltage values of the first pulse signal and the second pulse signal from the photoelectrically converted voltage signal, that is, the amplitude information of each of the first pulse signal and the second pulse signal. Extract. The measurement target node 20-b returns the extracted amplitude information to the master node 20-a.

  When the master node 20-a receives the optical signal transmitted from the measurement target node 20-b via the optical signal transmission path A, the transmission path length homogeneous particle 240-a is transmitted from the measurement target node 20-b. The distance of the optical signal transmission line A is derived from the amplitude information of the first pulse signal and the second pulse signal and the transmission path length information stored in advance.

<About transmission path information>
Here, the transmission path length information will be specifically described.
The optical signal of the multimode light transmitted through the optical signal transmission path is distorted in the signal waveform after photoelectric conversion according to the distance of the optical signal transmission path due to mode dispersion. FIG. 12 conceptually illustrates the relationship between the transmission distance and the signal waveform. As shown in FIG. 12, the signal waveform (i) having a transmission distance of 1 centimeter is hardly distorted, but the signal waveforms (ii) to (iii) are longer as the transmission distance is 1 m and 100 m. ) Is distorted.

  Further, the distortion of the signal waveform due to the mode dispersion in the optical signal of the multimode light has such a property that the lower the frequency of the transmission signal is, the smaller the distortion is, and the higher the frequency is. FIG. 13 is a diagram illustrating frequency characteristics (iv) to (vi) with respect to the amplitude of the received signal for each distance of the optical signal transmission path. As shown in FIG. 13, the longer the distance of the optical signal transmission path, the greater the amplitude degradation of the received signal. Similarly, the higher the frequency of the transmission signal, the greater the amplitude degradation of the received signal.

  For example, as shown in FIG. 11, when a 50 MHz pulse signal is transmitted as a multimode optical signal from the master node 20-a, the electrical signal after photoelectric conversion of the optical signal received by the measurement target node 20-b. The amplitude of A1 changes from A1 to A3 according to the distance of the optical signal transmission line A. Similarly, when a 5 GHz pulse signal is transmitted as a multimode optical signal, the amplitude of the received waveform changes from B1 to B3 according to the distance of the optical signal transmission path A.

As shown in FIG. 13, the frequency characteristic with respect to the amplitude of the transmission signal transmitted by the optical signal based on the multimode light has a certain inclination depending on the type of the optical signal transmission path and the distance of the optical signal transmission path. By utilizing such characteristics, the transmission path length information is obtained as shown in FIG. 13 for the frequency characteristics with respect to the amplitude of the transmission signal determined by the type and distance of the optical signal transmission path, that is, for each type of optical signal transmission path. It can be information representing the slope of the amplitude with respect to the frequency of the transmission signal in accordance with the distance of the optical signal transmission path.
Therefore, the optical signal transmission path is obtained by obtaining the frequency characteristics of the transmission signal transmitted through the optical signal transmission path that is the object of distance measurement and comparing the obtained frequency characteristics with previously stored transmission path information. Can be estimated.

The transmission path length deriving unit 240-a of the master node 20-a has frequency characteristics with respect to the amplitude of the transmission signal at a specific transmission distance for each type of optical signal transmission path as transmission path information (for example, as shown in FIG. 13). The frequency characteristics (iv) to (vi) of the amplitude every 1 centimeter, 1 meter, and 100 meters are stored.
It consists of a first pulse signal (frequency: 50 MHz) and a second pulse signal (frequency: 5 GHz) transmitted by the master node 20-a and received by the measurement target node 20-b via the optical signal transmission line A. Based on the amplitude information of the first pulse signal and the second pulse signal of the optical signal corresponding to the transmission path length measurement signal, the transmission path length deriving unit 240-a corresponds to the amplitude of the transmission signal in the optical signal transmission path A. The frequency characteristic is calculated, and the distance of the optical signal transmission line A is estimated by comparing it with transmission line length information stored in advance.
For example, as shown in FIG. 13, if the amplitude value represented by the amplitude information of the first pulse signal of 50 MHz is C1, and the amplitude value represented by the amplitude information of the second pulse signal of 5 GHz is C2, The transmission path length deriving unit 240-a can calculate the slope of the amplitude with respect to the frequency of the transmission signal in the optical signal transmission path A as C3, and can store the transmission path length information stored in advance and the calculated transmission signal frequency. The distance of the optical signal transmission line A can be estimated by comparing the amplitude gradient C3.

When the distance of the optical signal transmission path A is derived by the transmission path length deriving section 240-a, the optical signal output control section 250-a determines the derived distance of the optical signal transmission path A and the optical signal output control table 251-. The output level of the optical signal transmitted from the optical transmitter 211-a is determined based on the optical signal output control information stored in a, and the LDD 211-2a is transmitted to transmit the optical signal at the determined output level. Control.
For example, the distance of the optical signal transmission path A derived by the transmission path length derivation 240-a is 5 meters from the frequency characteristic of the amplitude of the transmission signal indicated by C3 in FIG. 13, and the type of the optical signal transmission path A is When the class of the optical fiber is OM3, the optical signal output control unit 250-a uses the optical signal output control information shown in Table 1 stored in the optical signal output control table 251-a as the optical signal transmission path. The optical signal output level corresponding to the distance A of 5 meters and the optical signal transmission line A type OM3 is selected. The optical signal output control unit 250-a controls the LDD 211-2a so that the optical signal is output from the LD 211-1a according to the output level of the selected optical signal.

Here, the master node 20-a and the measurement target node 20-b have been described with the functions divided for each node. However, all the nodes may have the functions of both the master node and the measurement target node. .
Each function of the optical communication device 20 according to the present embodiment is that a computer program (software) is installed in a computer (CPU), memory, and interface equipped in the optical communication device 20. The various functions of the optical communication device 20 described above are realized by the cooperation of various hardware resources of the computer and the computer program.
The computer program may be provided in a state of being stored in a computer-readable recording medium, or may be provided in a state of being readable by the computer via an electric communication line.

Next, the operation of the optical communication apparatus 20 according to the present embodiment will be described with reference to the flowchart shown in FIG. 14 with the optical signal transmission path length measurement master node as node A and the measurement target node as node B.
As shown in FIG. 14, when the setting of the number of transmissions of the transmission path length measurement signal is completed in node A (S201), node A determines the transmission path length measurement signal used for the measurement of the first transmission path length measurement signal. It is generated and transmitted to the node B (S step 202).

After transmitting the transmission path length measurement signal to the node B, the node A determines whether or not the transmission count of the transmission path length measurement signal has reached a preset transmission count (S203).
If the number of times of transmission has been reached (“Yes” in step S203), the generation and transmission operation of the transmission path length measurement signal by the node A ends (step S205).
On the other hand, if the number of transmissions has not been reached (“No” in step S203), node A generates a transmission line length measurement signal until the set number of transmissions is reached, and sends the generated transmission line measurement signal to node B. To send.

When the transmission path length measurement signal transmitted from the node A is received by the node B, the node B extracts voltage information, that is, amplitude information of the pulse signal included in the received transmission path length measurement signal (S step). 206). Since the transmission path length measurement signal includes a plurality of pulse signals having different frequencies, the node B determines whether or not all pulse signals included in the transmission path length measurement signal have been received (Sstep 207). ).
When all the pulse signals are not received (“No” in step S207), the node B completes the extraction of the amplitude information of the pulse signals included in the received transmission path length measurement signal for all the pulse signals. It continues until it does (Sstep 206).

On the other hand, when all the pulse signals have been received (“Yes” in step S207), the node B determines whether or not all the transmission path length measurement signals transmitted from the node A have been transmitted (step S). 208). Here, the determination of the number of transmissions of the transmission path length measurement signal by the node B is performed, for example, by changing the transmission path length measurement signal (the last transmission path length measurement signal) reaching the preset transmission count in the node A to the last transmission path. Information indicating that it is a length measurement signal is added and transmitted from node A, and node B can determine that it is the received transmission path length measurement signal.

  When all transmission path length measurement signals transmitted from node A are received (“Yes” in step S208), node B transmits all amplitude information to node A (Sstep 210). On the other hand, when all the transmission path length measurement signals transmitted from node A have not been received (“No” in step S208), node B receives the last transmission path length measurement signal transmitted from node A. Until the amplitude information is extracted from the received transmission path length measurement signal.

  When an optical signal including amplitude information is transmitted from node B and this optical signal is received at node A, node A transmits a transmission signal in an optical signal transmission path connecting node A and node B from the received amplitude information. Is calculated, and the distance of the optical signal transmission path between the node A and the node B is derived based on the transmission path length information stored in advance and the calculated frequency characteristic (S 211). .

When the distance of the optical signal transmission path between the node A and the node B is derived, the node A generates an optical signal based on the derived distance of the optical signal transmission path and the optical signal output control information stored in advance. The transmission output of the signal is determined (S step 212), and control is performed so that the output of the optical signal transmitted from the node A becomes the determined transmission output (S step 213).
Note that the first transmission path length measurement signal transmitted from the node A to the node B may be generated and transmitted when the node A is activated, and in the optical communication performed between the node A and the node B. It may be transmitted at a predetermined timing of data transmission.

Thus, according to the present embodiment, the frequency characteristic of the amplitude of the transmission signal in the optical signal transmission path is calculated from the amplitude information of the transmission path length measurement signal including a plurality of pulse signals of different frequencies, and the calculated frequency characteristics The optical signal transmission path is measured based on the optical signal transmission path, and the optical signal transmission output is controlled based on the characteristics and distance of the optical signal transmission path. Optimization can be performed.
Therefore, even in short-distance optical communications where transmission loss due to optical signal mode dispersion occurring in the transmission line is more dominant than transmission loss caused by the optical signal transmission line distance, optical signal mode dispersion It is possible to suppress the deterioration of transmission data caused by the above, realize a desired error rate, and maintain communication quality.

[Third Embodiment]
Next, an optical communication system with a large capacity including an optical communication apparatus according to a third embodiment of the present invention will be described with reference to FIG.
In addition, about the component of the optical communication apparatus concerning this Embodiment, the same code | symbol is attached | subjected to what has the same function and structure as the optical communication apparatus 20 demonstrated in 2nd Embodiment, and the detailed description Is omitted.

FIG. 15 illustrates an optical communication device 30-a serving as a transmission path length measurement master node and an optical communication device 30-b serving as a transmission path length measurement target node in the large-capacity intra-casing optical communication system according to the present embodiment. It is a block diagram which shows the structure of these.
Here, the transmission / reception length transmission signal transmission / reception configuration and the amplitude information extraction function, which are different from the configuration of each card in the large-capacity optical communication system described in the second embodiment, are mainly described. do.

  As illustrated in FIG. 15, the master node 30-a includes an optical transmission / reception unit 210-a that transmits and receives optical signals, a wavelength multiplexing unit 360-a that combines wavelengths of optical signals having different wavelengths, and a measurement target. A wavelength demultiplexing unit 370-a that receives an optical signal of laser light having a plurality of wavelengths transmitted from the node 30-b, demultiplexes the received optical signal into each wavelength, an amplitude information extraction unit 130-a, and a transmission Unlike the master node 20-a described in the second embodiment, the path length deriving unit 240-a and the optical signal output control unit 250 are different from the master node 20-a. Prepare for a.

On the other hand, the measurement target node 30-b receives the optical signal of the laser light having a plurality of wavelengths transmitted from the master node 30-a, and demultiplexes the received optical signal into each wavelength. And a wavelength combining unit 360-b for combining wavelengths of optical signals having different wavelengths and an optical signal transmitting / receiving unit 210-b for transmitting and receiving optical signals.
The wavelength demultiplexing unit 370-b selects an optical signal including the transmission path length measurement signal from the optical signals demultiplexed from the optical signal transmitted from the master node 30-a, and selects the selected optical signal. A configuration is provided in which the wavelength multiplexing unit 360-b is directly input.
Here, for example, AWG (Array Waveguide Grating) can be used for the wavelength multiplexing units 360-a and b and the wavelength demultiplexing units 370-a and b.

Next, in the optical communication system with large capacity in this embodiment, the operation of deriving the distance of the optical signal transmission path by the master node 30-a and the measurement target node 30-b will be described in detail with reference to FIG. Explained.
The optical transmission / reception unit 210-a of the master node 30-a transmits the transmission path length measurement signal and other packets at different wavelengths, and outputs optical signals of different wavelengths output from the optical transmission / reception unit 210-a. The optical signal is multiplexed into one optical signal by the multiplexing unit 360-a and output to the optical signal transmission line A.

The measurement target node 30-b demultiplexes the optical signal transmitted from the master node 30-a via the optical signal transmission path A into the optical signal of each wavelength by the wavelength demultiplexing unit 370-b.
The wavelength demultiplexing unit 370-b selects an optical signal including the transmission path length measurement signal from among the demultiplexed optical signals, and outputs this optical signal to the wavelength multiplexing unit 360-b. The signal is output to the optical receiver 212-b of the optical transceiver 210-b.
The wavelength multiplexing unit 360-b is an optical signal that includes the optical signal output from the optical transmission unit 211-b of the optical transmission / reception unit 210-b and the transmission path length measurement signal output from the wavelength demultiplexing unit 370-b. The signals are combined, and the combined optical signal is output to the optical signal transmission line A.

The optical signal output from the measurement target node 30-b is demultiplexed into optical signals of each wavelength by the wavelength demultiplexing unit 370-a of the master node A, and then photoelectrically converted and received by the optical signal transmitting / receiving unit 210-a. Is done.
In addition, among the optical signals demultiplexed by the wavelength demultiplexing unit 370-a, the optical signal including the transmission path length measurement signal transferred from the measurement target node 30-b is converted into a voltage by the optical receiving unit 212-a. After being converted into a signal, it is input to the amplitude information extraction unit 130-a.

  The amplitude information extracting unit 130-a extracts amplitude information of the transmission path length measurement signal transferred from the measurement target node 30-b from the input voltage signal, and the extracted amplitude information is transmitted to the transmission path length deriving unit 240. -A, and the transmission path length deriving section 240-a and the optical signal output control section 250-a perform the derivation of the optical signal transmission path length and the transmission level control of the optical signal.

  In the present embodiment, the master node 30-a transmits a transmission path length measurement signal and other communication packets at different wavelengths, and the measurement target node 30-b transmits a wavelength demultiplexing unit 370-b such as an AWG. , The optical signal containing the transmission path length measurement signal is demultiplexed and then multiplexed to another communication packet and returned to the master node 30-a. In the master node 30-a, the transmission path length measurement signal and other It is also possible to transmit a communication packet at the same wavelength, mount a switch unit such as an optical switch that dynamically switches the path in the measurement target node 30-b, and return the transmission path length measurement signal to the master node 30-a. Is possible.

Each function of the optical communication devices 30-a and 30b according to the present embodiment is a computer program stored in a computer (CPU), memory, and interface mounted on the optical communication devices 30-a and 30b. (Software) is installed, and the various functions of the optical communication devices 30-a and 30b described above are realized by the cooperation of the various hardware resources of the computer and the computer program.
The computer program may be provided in a state of being stored in a computer-readable recording medium, or may be provided in a state of being readable by the computer via an electric communication line.

  The present invention can be used for a large-capacity data communication system between cards of a computer system in which a plurality of CPU cards are mounted in a casing and information processing such as data transmission and arithmetic processing is performed in cooperation between the CPU cards.

  DESCRIPTION OF SYMBOLS 10 ... Optical communication apparatus, 110 ... Optical signal transmission / reception part, 120 ... Transmission path length measurement signal generation part, 130 ... Amplitude information extraction part, 140 ... Transmission path length derivation part, 150 ... Optical signal output control part.

Claims (9)

An optical signal transmission / reception unit for transmitting / receiving an optical signal to / from a communication partner via an optical signal transmission path;
A transmission path length measurement signal generation unit that generates a transmission path length measurement signal including a plurality of pulse signals having different frequencies, and outputs the transmission path length measurement signal to the optical signal transmission / reception unit;
When a transmission path length measurement signal is included in an optical signal transmitted from the communication partner and received by the optical signal transmission / reception unit, amplitude information of the plurality of pulse signals included in the transmission path length measurement signal is extracted. An amplitude information extraction unit;
Stores transmission path length information representing the relationship between the amplitude and frequency of the received signal according to the distance of the optical signal transmission path, and corresponds to each frequency of the plurality of pulse signals extracted by the amplitude information extraction unit. A transmission path length deriving unit for deriving a distance of the optical signal transmission path based on amplitude information and the transmission path length information;
Stores optical signal output control information indicating the transmission output of the optical signal transmission / reception unit according to the transmission path type and transmission path length distinguished by the frequency band of the transmittable optical signal, and is derived by the transmission path length deriving unit An optical signal for controlling the transmission output of the optical signal transmitted from the optical signal transmission / reception unit based on the distance of the optical signal transmission path, the transmission path type of the optical signal transmission path, and the optical signal output control information An optical communication device comprising: an output control unit. The optical communication device according to claim 1,
A plurality of optical signals output from the optical signal transmission / reception unit, each having a different wavelength, are combined into one optical signal and output to the communication partner via the optical signal transmission path; and
A wavelength demultiplexing unit that demultiplexes one optical signal received through the optical signal transmission path and including different wavelengths into a plurality of optical signals for each wavelength, and outputs the demultiplexed signal to the optical signal transmitting / receiving unit; Prepared,
The optical signal transmission / reception unit is configured to output the transmission path length measurement signal and other signals to the wavelength multiplexing unit as optical signals having different wavelengths. The optical communication device according to claim 2,
The wavelength demultiplexing unit, when the transmission path length measurement signal is included in the demultiplexed optical signals, outputs an optical signal corresponding to the transmission path length measurement signal to the wavelength multiplexing unit Configured,
The wavelength multiplexing unit multiplexes the plurality of optical signals output from the optical signal transmission / reception unit and the optical signal corresponding to the transmission path length measurement signal output from the wavelength demultiplexing unit. An optical communication device comprising: The optical communication device according to claim 1,
The optical signal transmission / reception unit includes:
An optical signal transmission unit including a laser element that emits laser light, and a laser element driving unit that converts an electrical signal into an optical signal to drive the laser element;
Light having a light receiving element that receives an optical signal and converts it into a current signal, a transimpedance amplifier that converts the current signal into a voltage signal, and a limiting amplifier that forms a waveform of the voltage signal output from the transimpedance amplifier An optical communication device comprising: a signal receiving unit. Generating a plurality of pulse signals having different frequencies as transmission path length measurement signals;
Transmitting an optical signal including the transmission path length measurement signal to a communication partner via the optical signal transmission path;
When the received optical signal includes the transmission path length measurement signal, extracting each of amplitude information of the plurality of pulse signals included in the transmission path length measurement signal;
Deriving the distance of the optical signal transmission path based on the transmission path length information indicating the relationship between the amplitude and frequency of the received signal according to the distance of the optical signal transmission path, and the amplitude information;
Optical signal output control information indicating the relationship of the transmission output of the optical signal output to the optical signal transmission path according to the transmission path type and the distance of the optical signal transmission path that are distinguished by the frequency band of the optical signal that can be transmitted; Determining the transmission output of the optical signal based on the distance of the optical signal transmission path and the transmission path type of the optical signal transmission path;
Controlling the transmission output of the optical signal output to the optical signal transmission path to a transmission output determined based on the optical signal output control information, the distance of the optical signal transmission path, and the transmission path type. An optical signal control method comprising: The optical signal control method according to claim 5,
Combining a plurality of optical signals having different wavelengths into one optical signal;
Demultiplexing one optical signal including different wavelengths into a plurality of optical signals for each wavelength, and
The step of combining comprises the step of combining the transmission path length measurement signal and other signals of different wavelengths into one optical signal,
The step of transmitting comprises the step of transmitting one signal obtained by multiplexing the transmission path length measurement signal and another signal to a communication partner via the optical signal transmission path. The optical signal control method according to claim 6,
The step of demultiplexing includes a step of outputting an optical signal corresponding to the transmission path length measurement signal as an optical signal to be multiplexed when the transmission path length measurement signal is included in the plurality of demultiplexed optical signals. An optical signal control method comprising: On the computer,
Generating a plurality of pulse signals having different frequencies as transmission path length measurement signals;
Transmitting an optical signal including the transmission path length measurement signal to a communication partner via the optical signal transmission path;
When the received optical signal includes the transmission path length measurement signal, extracting each of amplitude information of the plurality of pulse signals included in the transmission path length measurement signal;
Deriving the distance of the optical signal transmission path based on the transmission path length information indicating the relationship between the amplitude and frequency of the received signal according to the distance of the optical signal transmission path, and the amplitude information;
Optical signal output control information indicating the relationship of the transmission output of the optical signal output to the optical signal transmission path according to the transmission path type and the distance of the optical signal transmission path that are distinguished by the frequency band of the optical signal that can be transmitted; Determining the transmission output of the optical signal based on the distance of the optical signal transmission path and the transmission path type of the optical signal transmission path;
Controlling the transmission output of the optical signal output to the optical signal transmission path to a transmission output determined based on the optical signal output control information, the distance of the optical signal transmission path, and the transmission path type. program to be executed. Comprising a plurality of optical communication devices connected via at least one optical signal transmission line;
Each of the plurality of optical communication devices is
An optical signal transmission / reception unit for transmitting / receiving an optical signal to / from a communication partner via an optical signal transmission path;
A transmission path length measurement signal generation unit that generates a transmission path length measurement signal including a plurality of pulse signals having different frequencies, and outputs the transmission path length measurement signal to the optical signal transmission / reception unit;
When a transmission path length measurement signal is included in an optical signal transmitted from the communication partner and received by the optical signal transmission / reception unit, amplitude information of the plurality of pulse signals included in the transmission path length measurement signal is extracted. An amplitude information extraction unit;
Stores transmission path length information representing the relationship between the amplitude and frequency of the received signal according to the distance of the optical signal transmission path, and corresponds to each frequency of the plurality of pulse signals extracted by the amplitude information extraction unit. A transmission path length deriving unit for deriving a distance of the optical signal transmission path based on amplitude information and the transmission path length information;
Stores optical signal output control information indicating the transmission output of the optical signal transmission / reception unit according to the transmission path type and transmission path length distinguished by the frequency band of the transmittable optical signal, and is derived by the transmission path length deriving unit An optical signal for controlling the transmission output of the optical signal transmitted from the optical signal transmission / reception unit based on the distance of the optical signal transmission path, the transmission path type of the optical signal transmission path, and the optical signal output control information An optical communication system comprising: an output control unit.

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