Optical communication device, optical cable, and optical communication system

Abstract

The present invention enables an apparatus (optical communication device) in an optical communication system to acquire specifications of an optical cable or the like and to perform processing that corresponds to the acquired specifications.　This optical communication device comprises a receptacle, a transmission unit having a plurality of transmission channels, a reception unit having a plurality of reception channels, and a control unit. The control unit detects the specifications of the optical cable in accordance with the reception status, at the reception unit, of a return optical signal from the optical cable.

Description

Optical communication device, optical cable and optical communication system

[0001] The present technology relates to an optical communication device, an optical cable, and an optical communication system, and more particularly to an optical communication device or the like that can detect the specifications of an optical cable.

[0002] In an optical communication system using an optical cable, the specifications and settings of the equipment (optical communication device) must match the cable specifications and the specifications and settings of the device (optical communication device) to be connected.

[0003] JP 2012-156945 A

[0004] An object of this technology is to enable equipment (optical communication devices) in an optical communication system to acquire specifications of optical cables and the like and to perform processing in accordance with the acquired specifications.

[0005] The concept of the present technology resides in an optical communication device comprising: a receptacle; a transmitting unit having a plurality of transmitting channels; a receiving unit having a plurality of receiving channels; a plug configured to be able to fit with the receptacle; one or more connected channel sets including a connected transmitting channel and a connected receiving channel corresponding to the connected transmitting channel; one or more unconnected channel sets including an unconnected transmitting channel and an unconnected receiving channel corresponding to the unconnected transmitting channel; and an optical return mechanism that causes an incident optical signal transmitted from any of the plurality of transmitting channels of the transmitting unit and incident on the unconnected transmitting channel via the plug to be output as a returned optical signal via the plug from the unconnected receiving channel included in the unconnected channel set including the unconnected transmitting channel.

[0006] The optical communication device according to the present technology includes a receptacle, a transmitter having a plurality of transmission channels, a receiver having a plurality of reception channels, and a controller, and the controller detects the specifications of the optical cable according to the reception status of the receiver of the return optical signal from the optical cable.

[0007] Here, the optical cable has a plug configured to be able to mate with the receptacle, one or more connection channel sets including a connection transmitting channel and a connection receiving channel corresponding to the connection transmitting channel, one or more non-connection channel sets including a non-connection transmitting channel and a non-connection receiving channel corresponding to the non-connection transmitting channel, and an optical return mechanism that causes an incident optical signal transmitted from one of the multiple transmitting channels of the transmitter and input to the non-connection transmitting channel via the plug to be output as a return optical signal via the plug from a non-connection receiving channel included in the non-connection channel set including the non-connection transmitting channel.

[0008] For example, the control unit may detect, as a specification, a channel connection state indicating whether each of the input / output channel sets, each of which includes each of the receiving channels and the corresponding transmitting channel, is a connected channel set or a non-connected channel set, based on whether each of the receiving channels of the receiving unit has received a return optical signal. This makes it possible to detect the channel connection state as a specification of the optical cable.

[0009] In this case, for example, the control unit may set the connected channel set as a used channel set or an available channel set. This makes it possible to effectively set the used channel set or the available channel set. Here, the used channel set means a channel set that is always used, and the available channel set means a channel set that is available but may not be used, and whether to use it or not is determined by additional setting. Also, in this case, for example, the control unit may perform power reduction processing for communication using the non-connected channel set.

[0010] Furthermore, for example, the control unit may detect the number of connection channel sets as a specification of the optical cable according to the number of reception channels that receive return optical signals from the plug of the optical cable, among the plurality of reception channels, thereby making it possible to detect the number of connection channel sets as a specification of the optical cable.

[0011] Furthermore, for example, the control unit may detect the specifications of the optical cable based on an input / output channel connection relationship indicating which receiving channel of which transmitting channel of the transmitting unit receives a return optical signal. This enables accurate detection of the specifications of the optical cable. In this case, for example, the transmitting unit may emit an optical signal capable of identifying a channel number from at least some of the transmitting channels among the plurality of transmitting channels. Here, the specifications of the optical cable may include, for example, at least one of a channel set connection status indicating whether each channel set of the optical cable is a connected channel set or a non-connected channel set, the number of connected channel sets, an optical wavelength, an insertion loss, a fiber type, a total transmission bandwidth, and a cable length.

[0012] Furthermore, for example, the control unit may be configured to configure optical communication settings to match the specifications of the optical cable. As a result, the optical communication settings are configured to match the specifications of the optical cable. Furthermore, for example, the control unit may be configured to perform a warning process when the optical cable specifications cannot be met. This allows the user to know that the device cannot meet the optical cable specifications, and to prompt the user to replace the optical cable with one that is compatible with the device.

[0013] Furthermore, for example, the control unit may be configured to determine whether the optical cable is broken based on a cable breakage confirmation response optical signal that is transmitted from the external device in response to a cable breakage confirmation optical signal transmitted via the connection transmission channel to the external device connected via the optical cable and received by the receiving unit, thereby making it possible to determine whether the optical cable is broken.

[0014] In this case, for example, the control unit may be configured to determine that the optical cable is damaged when the number of receiving channels indicated by the cable breakage confirmation response optical signal does not match the number of connected transmitting channels. Also, in this case, for example, the control unit may be configured to determine that the input / output channel set of the optical cable corresponding to the connected transmitting channel with the mismatched channel number is damaged when the receiving channel number indicated by the cable breakage confirmation response optical signal does not match the channel number of the connected transmitting channel. In this case, it is possible to determine damage for each input / output channel set.

[0015] In this case, for example, the control unit may be configured to execute a warning process when it is determined that the optical cable is damaged, thereby making it possible to notify the user that the optical cable is damaged and to prompt the user to replace the optical cable with an undamaged one.

[0016] In this way, in this technology, the specifications of the optical cable are detected according to the reception status at the receiving section of the return optical signal from the optical cable, and the specifications of the optical cable can be acquired.

[0017] Another concept of the present technology is an optical cable having: a plug configured to be able to fit into a receptacle of an optical communication device; one or more connection channel sets including a connection transmitting channel and a connection receiving channel corresponding to the connection transmitting channel; one or more non-connection channel sets including a non-connection transmitting channel and a non-connection receiving channel corresponding to the non-connection transmitting channel; and an optical return mechanism that causes an incident optical signal that is transmitted from one of a plurality of transmitting channels of a transmitting unit of the optical communication device and is incident on the non-connection transmitting channel via the plug to be output as a return optical signal from a non-connection receiving channel included in the non-connection channel set including the non-connection transmitting channel toward a receiving unit of the optical communication device via the plug.

[0018] The present technology includes a plug configured to be matable with a receptacle of an optical communication device, one or more connection channel sets including a connection transmitting channel and a connection receiving channel corresponding to the connection transmitting channel, one or more non-connection channel sets including a non-connection transmitting channel and a non-connection receiving channel corresponding to the non-connection transmitting channel, and an optical return mechanism.

[0019] With this optical return mechanism, an incident optical signal transmitted from one of a plurality of transmission channels of a transmitter of an optical communication device and input to an unconnected transmission channel via a plug is output as a return optical signal from an unconnected reception channel included in an unconnected channel set including the unconnected transmission channel via the plug toward a receiver of the optical communication device. For example, the optical return mechanism may be configured using a mirror or an optical waveguide. Also, for example, plugs having an optical return mechanism may be provided at both ends of an optical cable main body.

[0020] Furthermore, for example, the optical return mechanism may include an input / output channel connection relationship changing mechanism for causing an incident optical signal input to each of the unconnected transmit channels to be output from one of the unconnected receive channels based on the input / output channel connection relationship according to the specifications of the optical cable. This enables the optical communication device to accurately detect the specifications of the optical cable. In this case, for example, the specifications of the optical cable may include at least one of a channel set connection status indicating whether each channel set of the optical cable is a connected channel set or an unconnected channel set, the number of connected channel sets, the optical wavelength, the insertion loss, the fiber type, the total transmission bandwidth, and the cable length.

[0021] In this way, the present technology has an optical return mechanism that outputs an incident optical signal, which is transmitted from one of a plurality of transmission channels of the transmitting section of the optical communication device and is input to the non-connected transmitting channel via a plug, as a return optical signal from a non-connected receiving channel included in a non-connected channel set that includes the non-connected transmitting channel, towards the receiving section of the optical communication device via the plug, and it becomes possible for the optical communication device to detect the specifications of the optical cable depending on the reception status at the receiving section.

[0022] Another concept of the present technology resides in an optical communication system including an optical communication device and an optical cable connected to the optical communication device, wherein the optical cable has: a plug configured to be able to fit into a receptacle of the optical communication device; one or more connected channel sets including a connected transmitting channel and a connected receiving channel corresponding to the connected transmitting channel; one or more unconnected channel sets including an unconnected transmitting channel and an unconnected receiving channel corresponding to the unconnected transmitting channel; and an optical return mechanism that causes an incident optical signal, which is transmitted from any of a plurality of transmitting channels of a transmitting section of the optical communication device and is incident on the unconnected transmitting channel via the plug, to be output as a returned optical signal from an unconnected receiving channel included in the unconnected channel set including the unconnected transmitting channel towards a receiving section of the optical communication equipment via the plug, and the optical communication device includes: the receptacle; the transmitting section having a plurality of transmitting channels; the receiving section having a plurality of receiving channels; and a control section that detects specifications of the optical cable according to a reception status of the returned optical signal from the optical cable at the receiving section.

[0023] FIG. 1 is a diagram illustrating an example of the configuration of an optical communication system according to an embodiment. FIG. 1 is a diagram for explaining an example of the configuration of an optical return mechanism. FIG. 1 is a diagram illustrating an example of the correspondence relationship between unconnected receive channels and unconnected transmit channels in a plug. FIG. 2 is a diagram illustrating an example of a case where a channel number identification optical signal is a pulse signal. FIG. 2 is a flowchart illustrating an example of a processing procedure for detecting optical cable specifications, etc., in a control unit of a device. FIG. 3 is a flowchart illustrating an example of a procedure for cable specification detection processing and cable specification compatible communication setting processing. FIG. 4 is a flowchart illustrating another example of a procedure for cable specification detection processing and cable specification compatible communication setting processing. FIG. 4 is a diagram illustrating an example of correspondence relationship information between the number of connected channel sets and a transmittable bandwidth. FIG. 5 is a flowchart illustrating yet another example of a procedure for cable specification detection processing and cable specification compatible communication setting processing. FIG. 5 is a diagram illustrating an example of correspondence relationship information between input / output channel connection relationships and optical cable specifications. FIG. 6 is a flowchart illustrating another example of correspondence relationship information between input / output channel connection relationships and optical cable specifications. Fig. 10 is a flowchart showing another example of the processing procedure for detecting the specifications of an optical cable (damage detection is also possible) in the control unit of the device.Fig. 11 is a block diagram showing an example of the hardware configuration of a computer.

[0024] The following describes modes for carrying out the invention (hereinafter referred to as "embodiments"). The description will be given in the following order: 1. Embodiment 1-1. Example of the configuration of an optical communication system 1-1-1. Description of optical cable 1-1-2. Description of equipment 1-1-2-1. Processing procedures for detecting equipment specifications, etc. 1-1-2-2. Other processing procedures for detecting equipment specifications, etc. 1-1-3. Software processing 2. Modified examples

[0025] 1 shows an example of the configuration of an optical communication system 10 according to an embodiment. In this optical communication system 10, a device (device A) 100 and a device (device B) 200 are connected via an optical cable 300. Here, the devices 100 and 200 constitute an optical communication device (optical communication device).

[0026] The optical cable 300 has multiple channels. For example, the optical cable 300 has multiple optical fibers corresponding to the multiple channels. In this case, for example, the optical cable 300 may be a so-called ribbon-type optical cable in which the optical fibers are arranged in a row, or a so-called bundle-type optical cable in which the optical fibers are arranged in a cylindrical resin tube. Furthermore, for example, the optical cable 300 may have a multi-core optical fiber having multiple cores corresponding to the multiple channels within a single optical fiber.

[0027] "1-1-1. Description of Optical Cable" The optical cable 300 will be described. The optical cable 300 is configured such that a plug (plug A) 302 and a plug (plug B) 303 are connected to one end and the other end of an optical cable main body 301, respectively. The plug 302 of the optical cable 300 is connected to a receptacle 101 serving as a connector of the device 100, and the plug 303 of the optical cable 300 is connected to a receptacle 201 serving as a connector of the device 200.

[0028] Each of the plugs 302 and 303 has six transmit channels, from transmit channel 1 (tch1) to transmit channel 6 (tch6), and six receive channels, from receive channel 1 (rch1) to receive channel 6 (rch6). The channel numbers are determined in advance. The number of channel sets, consisting of pairs of transmit and receive channels, is not limited to six, and other numbers greater than six, such as 12 or 24, are also possible. However, for simplicity of explanation, this embodiment will be described using an example in which the number of channel sets is six.

[0029] In the plugs 302 and 303, a predetermined number of transmitting channels and receiving channels are designated as unconnected channels. Here, the unconnected channels include channels for which no optical fiber corresponding to the channel exists in the optical cable main body 301 and communication is not possible, as well as channels for which an optical fiber corresponding to the channel exists in the optical cable main body 301 but is not connected and communication is not possible. In the illustration, an example is shown in which the predetermined number is three and three transmitting channels, channel 6 (ch6) to channel 4 (ch4), are unconnected channels, but this is not limiting.

[0030] The plugs 302 and 303 have optical return mechanisms 321 and 331, respectively. The optical return mechanism 321 will be described. The optical return mechanism 331 is configured similarly to the optical return mechanism 321, and therefore will not be described here. The optical return mechanism 321 outputs an optical signal that has been input to an unconnected transmitting channel among the six transmitting channels as a return optical signal from an unconnected receiving channel among the six receiving channels.

[0031] The optical return mechanism 321 is configured using, for example, a mirror or an optical waveguide. Figure 2(a) shows an example of the configuration of the optical return mechanism 321 configured using a mirror. This example shows a case where three transmission channels, from transmission channel 6 (tch6) to transmission channel 4 (tch4), are unconnected transmission channels, and three reception channels, from reception channel 6 (rch6) to reception channel 4 (rch4), corresponding to these unconnected transmission channels, are unconnected reception channels. In this case, three transmission channels, from transmission channel 3 (tch3) to transmission channel 1 (tch1), are connected transmission channels, and three reception channels, from reception channel 3 (rch3) to reception channel 1 (rch1) corresponding to these connected transmission channels, are connected reception channels.

[0032] The optical return mechanism 321 is composed of a first mirror 321a that changes the optical paths of optical signals that are input to each of the three transmission channels (unconnected transmission channels) from transmission channel 6 (tch6) to transmission channel 4 (tch4) of the plug 302 in a perpendicular direction, and a second mirror 321b that changes the optical paths of each optical signal whose optical path has been changed in a perpendicular direction and outputs the optical signals as return optical signals from the three reception channels (unconnected reception channels) from reception channel 6 (rch6) to reception channel 4 (rch4) of the plug 302.

[0033] 2(a) shows an example in which optical signals input to transmitting channels 6, 5, and 4 are output from receiving channels 6, 5, and 4, respectively, but an input / output channel connection relationship change mechanism is provided to enable each optical signal input to transmitting channels 6, 5, and 4 to be selectively output as a return optical signal from one of receiving channels 6, 5, and 4 by setting the input / output channel connection relationship through the arrangement of mirrors 321a and 321b. For example, when the position and angle of the second mirror 321b are set as shown in FIG. 2(b), each optical signal input to transmitting channels 6, 5, and 4 is output from receiving channels 4, 5, and 6 as a return optical signal.

[0034] 2C shows an example of the configuration of an optical return mechanism 321 configured using an optical waveguide. This example also shows a case where three transmission channels, from transmission channel 6 (tch6) to transmission channel 4 (tch4), are unconnected transmission channels, and three reception channels, from reception channel 6 (rch6) to reception channel 4 (rch4) corresponding to these unconnected transmission channels, are unconnected reception channels.

[0035] The optical return mechanism 321 is composed of an optical waveguide 321c that guides optical signals input to the three transmission channels (unconnected transmission channels) from transmission channel 6 (tch6) to transmission channel 4 (tch4) of the plug 302 to the three reception channels (unconnected reception channels) from reception channel 6 (rch6) to reception channel 4 (rch4) of the plug 302, respectively, and outputs them as return optical signals.

[0036] 2(c) shows an example in which optical signals input to transmitting channels 6, 5, and 4 are output from receiving channels 6, 5, and 4, respectively, but an input / output channel connection relationship changing mechanism is provided for selectively outputting each of the optical signals input to transmitting channels 6, 5, and 4 as return optical signals from one of receiving channels 6, 5, and 4, depending on the input / output channel connection relationship set by the waveguide connection setting of the optical waveguide 321c. For example, when the input / output channel connection relationship of the optical waveguide 321c is set as shown in FIG. 2(d), each of the optical signals input to transmitting channels 6, 5, and 4 is output from receiving channels 4, 5, and 6 as return optical signals.

[0037] In this embodiment, in plugs 302 and 303, the optical signals input to a predetermined number of unconnected transmitting channels are output as return optical signals from which of the predetermined number of unconnected receiving channels based on a setting predetermined according to the specifications of optical cable 300, and optical cables 300 are manufactured according to each specification, so that the specifications of optical cable 300 can be detected by devices 100 and 200. In this case, the specifications of optical cable 300 include at least one of the channel set connection state indicating whether each channel set is a connected channel set or an unconnected channel set, the number of connected channel sets, optical wavelength, insertion loss, fiber type, total transmission bandwidth, and cable length.

[0038] For example, if the unconnected channel set consists of two channels, channel 6 (ch6) and channel 5 (ch5), the setting as to which of the two transmitting channels, transmitting channel 6 (tch6) and transmitting channel 5 (tch5), an optical signal input from the two receiving channels, receiving channel 6 (rch6) and receiving channel 5 (rch5), is to be output as a return optical signal is selectively set to, for example, either a or b in Figure 3(a), which indicates one specification of the optical cable 300, for example, the optical wavelength.

[0039] In this case, the device 100 detects that the optical wavelength specified for the optical cable 300 is, for example, "850 [nm]" based on the fact that the optical signal of the transmission channel of transmission channel 5 (tch5) is received as a return optical signal at the reception channel of reception channel 5 (rch5). Also, in this case, the device 100 detects that the optical wavelength specified for the optical cable 300 is, for example, "1310 [nm]" based on the fact that the optical signal of the transmission channel of transmission channel 5 (tch5) is received as a return optical signal at the reception channel of reception channel 6 (rch6).

[0040] Furthermore, if the unconnected channel set consists of three channels, channel 6 (ch6) to channel 4 (ch4), the setting as to which of the three transmitting channels, transmit channel 6 (tch6) to transmit channel 4 (tch4), the optical signal input from the three receiving channels, receive channel 6 (rch6) to receive channel 4 (rch4), will be output as a return optical signal is selectively set to, for example, one of a to d in Figure 3(b), and two specifications of the optical cable 300, such as the optical wavelength and insertion loss, are indicated.

[0041] In this case, the device 100 detects the optical wavelength as specified for the optical cable 300, just as in the case where the unconnected channel set described above includes two channels, channel 6 (ch6) and channel 5 (ch5). Furthermore, in this case, the device 100 detects that the insertion loss as specified for the optical cable 300 is, for example, "less than 3 dB" based on the fact that the optical signal of the transmission channel, transmission channel 4 (tch4), is received as a return optical signal at the reception channel, reception channel 4 (rch4). Furthermore, in this case, the device 100 detects that the insertion loss as specified for the optical cable 300 is, for example, "3 to 6 dB" based on the fact that the optical signal of the transmission channel, transmission channel 6 (tch6), is received as a return optical signal at the reception channel, reception channel 4 (rch4).

[0042] Furthermore, if the unconnected channel set consists of five channels, channel 6 (ch6) to channel 2 (ch2), the setting for which of the five receiving channels, receiving channel 6 (rch6) to receiving channel 2 (rch2), and the five transmitting channels, transmitting channel 6 (tch6) to transmitting channel 2 (tch2), the optical signal input to should be output as a return optical signal is selectively set to any of a to h in Figure 3(c), and indicates three specifications of the optical cable 300, such as the optical wavelength, insertion loss, and fiber type.

[0043] In this case, the device 100 detects the optical wavelength and insertion loss as specifications of the optical cable 300, just as in the case where the unconnected channel set described above includes three channels, channel 6 (ch6) through channel 4 (ch4). Furthermore, in this case, the device 100 detects that the fiber type as specifications of the optical cable 300 is "MMF (multi-mode optical fiber)" based on the fact that the optical signal of the transmission channel, transmission channel 3 (tch3), is received as a return optical signal at the reception channel, reception channel 3 (rch3). Furthermore, in this case, the device 100 detects that the fiber type as specifications of the optical cable 300 is "SMF (single-mode optical fiber)" based on the fact that the optical signal of the transmission channel, transmission channel 2 (tch2), is received as a return optical signal at the reception channel, reception channel 3 (rch3).

[0044] The specification determination methods shown in Figures 3(a), (b), and (c) are designed so that the specification determination method in Figure 3(a) can be used in common with the specification determination methods in Figures 3(b) and (c), and the specification determination method in Figure 3(b) can be used with the specification determination method in Figure 3(c). Although a detailed explanation will be omitted, by determining the specifications independently for cases where the number of unconnected channels is, for example, 2, 3, 5, etc., it becomes possible to incorporate even more specification information, such as cable length.

[0045] "1-1-2. Description of Devices" The devices 100 and 200 will now be described. In addition to the receptacle 101 as the connector described above, the device 100 has a control unit 102, a communication signal input / output unit 103, a signal processing unit 104, a transmitting unit 105T, a receiving unit 105R, a presentation unit 106, and a memory unit 107. The control unit 102 controls the operation of each unit of the device 100. The presentation unit 106 is composed of a display, a speaker, etc., and displays the operating status of the device 100 and warnings to the user on the display, or outputs audio warnings from the speaker. The memory unit 107 stores various information.

[0046] The signal processing unit 104 performs signal processing to convert the transmission data into a signal suitable for optical communication and sends it to the light emitting element (laser, etc.) of each transmission channel of the transmission unit 105 T. The signal processing unit 104 also performs predetermined signal processing on the reception data sent from the light receiving element (photodiode, etc.) of each reception channel of the reception unit 105 R.

[0047] Transmission data acquired from an external device connected via the Internet or the like, or output from a predetermined internal location, such as the control unit 102 or a recording unit (not shown), is supplied to the signal processing unit 104 via the communication signal input / output unit 103. Furthermore, received data obtained by the signal processing unit 104 is appropriately supplied to the control unit 102 or a predetermined internal location, such as an external device connected via the Internet or a recording unit (not shown), via the communication signal input / output unit 103. Note that in control communications such as specification detection, data is exchanged between the signal processing unit 104 and the control unit 102, and actual data is exchanged via the communication signal input / output unit 103 and the signal processing unit 104.

[0048] Although detailed explanation of device 200 is omitted, it is configured in the same manner as device 100 described above, and in addition to receptacle 201 as the connector described above, it has a control unit 202, a communication signal input / output unit 203, a signal processing unit 204, a transmitting unit 205T, a receiving unit 205R, a presentation unit 206, and a memory unit 207.

[0049] When the optical cable 300 is connected to the device 100, the plug 302 of the optical cable 300 is fitted into the receptacle 101 of the device 100. In this case, the six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the transmitter 105T of the device 100 are respectively connected to the six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the plug 302 of the optical cable 300. Also, the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6) of the receiver 105R of the device 100 are respectively connected to the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6) of the plug 302 of the optical cable 300.

[0050] Furthermore, when the optical cable 300 is connected to the device 200, the plug 303 of the optical cable 300 is fitted into the receptacle 201 of the device 200. In this case, the six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the transmitter 205T of the device 200 are respectively connected to the six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the plug 303 of the optical cable 300. Furthermore, the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6) of the receiver 205R of the device 200 are respectively connected to the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6) of the plug 303 of the optical cable 300.

[0051] The device 200 has the same configuration as the device 100, so the following description will focus on the device 100 and omit the description of the device 200.

[0052] After powering on, the control unit 102 of the device 100 detects the specifications of the optical cable 300 before starting communication of actual data such as images and audio with the device 200, and sets up optical communication settings to match the specifications of the optical cable 300. Here, the specifications of the optical cable 300 include at least one of the channel set connection status indicating whether each channel set is a connected channel set or a non-connected channel set, the number of connected channel sets, the optical wavelength, the insertion loss, the fiber type, the total transmission bandwidth, and the cable length, and the settings for optical communication include, for example, settings for the transmission bandwidth, the optical wavelength, the optical output level, etc.

[0053] In this case, the control unit 102 inputs optical signals from the six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the transmitter 105T to the six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the plug 302 of the optical cable 300, and detects the specifications of the optical cable 300 based on the reception status of return optical signals from the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6), of the plug 302 of the optical cable 300, in the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6) of the receiver 105R.

[0054] It is not necessary for the transmitter 105T to input optical signals to all transmission channels from transmission channel 1 (tch1) to transmission channel 6 (tch6) of the plug 302 of the optical cable 300, but the optical signals may be input to only at least some of the transmission channels including non-connected transmission channels. For example, if it is guaranteed that the range from transmission channel 1 (tch1) to transmission channel N (tchN) of the plug 302 of the optical cable 300 is connected transmission channels, that is, if this is set as a predetermined rule, it is not necessary to input optical signals to the transmission channels in the range from transmission channel 1 (tch1) to transmission channel N (tchN).

[0055] Furthermore, it is not necessary to detect the specifications of the optical cable 300 based on the reception status of return optical signals in all reception channels from reception channel 1 (rch1) to reception channel 6 (rch6) of the receiving unit 105R, but the specifications of the optical cable 300 may be detected based on the reception status of return optical signals in at least some reception channels, including reception channels corresponding to unconnected reception channels of the plug 302 of the optical cable 300. For example, if it is guaranteed that the range from reception channel 1 (rch1) to reception channel N (rchN) of the plug 302 of the optical cable 300 is connected reception channels, the reception channels in the range from reception channel 1 (rch1) to reception channel N (rchN) will never receive return optical signals, and therefore it is not necessary to refer to the reception status of return optical signals in the reception channels in the range from reception channel 1 (rch1) to reception channel N (rchN).

[0056] When the control unit 102 of the device 100 detects the specifications of the optical cable 300, such as the channel set connection status indicating whether each channel set is a connected channel set or a non-connected channel set and the number of connected channel sets, the control unit 102 causes the transmitter 105T to input non-connected channel confirmation optical signals as optical cable specification detection optical signals to six transmission channels, from transmission channel 1 (tch1) to transmission channel 6 (tch6), of the plug 302 of the optical cable 300. This non-connected channel confirmation optical signal does not need to be an optical signal whose channel number can be identified, but may be, for example, an optical signal with a constant continuous power. However, while a constant continuous power is preferable to achieve high detection accuracy, it does not have to be constant within a detectable range.

[0057] Furthermore, when the control unit 102 of the device 100 detects the specifications of the optical cable 300, such as the optical wavelength, insertion loss, fiber type, total transmission bandwidth, and cable length, the control unit 102 causes the transmitter 105T to input channel number identification optical signals as optical signals, i.e., optical cable specification detection optical signals, to six transmission channels, from transmission channel 1 (tch1) to transmission channel 6 (tch6), of the plug 302 of the optical cable 300. In this case, the reception status of the return optical signals in the reception channels, from reception channel 1 (rch1) to reception channel 6 (rch6) in the receiver 105R, can include not only information on whether or not a return optical signal has been received, but also information on which transmission channel the received return optical signal belongs to.

[0058] The channel number identification optical signal is, for example, a pulse signal that identifies the channel number based on the number of pulses, pulse timing, pulse width, etc. However, the signal is not limited to this and may identify the channel number based on a value, wavelength, etc. Furthermore, the channel number identification optical signal does not change its value depending on the transmission channel number, and may be, for example, a signal of constant power as described above. In this case, it is possible to identify the transmission channel number by performing time-division processing, for example.

[0059] 4(a) to 4(c) show examples in which the channel number identification optical signal is a pulse signal. Fig. 4(a) shows an example in which the channel number is identified by the number of pulses. For example, as shown in the figure, the number of pulses in the channel number identification optical signal for channel 1 (Ch1) is 1, the number of pulses in the channel number identification optical signal for channel 2 (Ch2) is 2, and so on for the subsequent channels 3 (Ch3) to 6 (Ch6).

[0060] 4B shows an example in which channel numbers are identified by pulse timing. For example, as shown in the figure, the pulse timing of the channel number identification optical signal for channel 1 (Ch1) is the earliest first timing t1, the pulse timing of the channel number identification optical signal for channel 2 (Ch2) is the second timing t2 that is later than the first timing t1, and the same applies to subsequent channels 3 (Ch3) to 6 (Ch6).

[0061] 4(c) shows an example in which channel numbers are identified by pulse width. For example, as shown in the figure, the pulse width of the channel number identification optical signal for channel 1 (Ch1) is the shortest first width w1, the pulse width of the channel number identification optical signal for channel 2 (Ch2) is the second width w2 that is longer than the first width w1, and so on for subsequent channels 3 (Ch3) to 6 (Ch6).

[0062] 1-1-2-1. Processing Procedure for Device Specification Detection, etc. The flowchart in FIG. 5 shows an example of processing procedure for detecting the specifications of the optical cable 300, etc., in the control unit 102 of the device 100.

[0063] First, the control unit 102 starts processing in step ST1. Next, the control unit 102 transmits optical cable specification detection signals in step ST2. In this case, the optical cable specification detection signals are input from six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the transmitter 105T to six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6) of the plug 302 of the optical cable 300. Note that the optical cable specification detection signals are optical signals only for detecting the optical cable specification, and are therefore transmitted only at this timing before the start of communication of actual data such as images and audio.

[0064] Next, in step ST3, the control unit 102 determines whether or not an optical cable specification detection optical signal has been received as a return optical signal. In this case, the control unit 102 monitors the reception status of return optical signals (here, whether or not an optical signal has been received) in six reception channels, from reception channel 1 (rch1) to reception channel 6 (rch6) of the receiving unit 105R, and determines that an optical cable specification detection optical signal has been received when an optical cable specification detection optical signal has been received as a return optical signal in any reception channel; otherwise, it determines that an optical cable specification detection optical signal has not been received.

[0065] When it is determined that an optical cable specification detection optical signal has not been received, the entire channel set is included in the connected channel set. In this case, when determining that an optical cable specification detection optical signal has not been received, it is possible to use only some of the channel sets rather than the entire channel set, depending on the situation, such as when a low transmission data rate is acceptable. Therefore, when it is determined that an optical cable specification detection optical signal has not been received, the control unit 102 sets the entire channel set as the used channel set or available channel set in step ST4, and then terminates the processing in step ST5. Here, the used channel set refers to a channel set that is always used, and the available channel set refers to a channel set that is available but may not be used, and whether to use it or not is determined by additional settings.

[0066] When it is determined in step ST3 that an optical cable specification detection optical signal has been received, the control unit 102 performs a cable specification detection process in step ST6, then performs a cable specification compatible communication setting process in step ST7, and then terminates the process in step ST5.

[0067] The flowchart in Fig. 6(a) shows an example of the procedure for the cable specification detection process in step ST6 of the flowchart in Fig. 5. In this example, the optical cable specification detection optical signal transmitted in step ST2 of the flowchart in Fig. 5 may be either the non-connected channel confirmation optical signal or the channel number identification optical signal described above.

[0068] First, the control unit 102 starts processing in step ST11. Next, in step ST12, the control unit 102 performs a "specification 1 detection" process, i.e., determines whether each channel set of the optical cable 300 is a connected channel set or a non-connected channel set, and detects the channel set connection status indicating whether each channel set is a connected channel set or a non-connected channel set as a specification of the optical cable 300. Thereafter, in step ST13, the control unit 102 ends processing.

[0069] In this case, in step ST12, the control unit 102 monitors the reception status of the return optical signals in the six receiving channels of the receiving unit 105R, from receiving channel 1 (rch1) to receiving channel 6 (rch6), and determines the channel set corresponding to the receiving channel that received the return optical signal as a non-connected channel set, while determining the channel set corresponding to the receiving channel that did not receive the return optical signal as a connected channel set.

[0070] The flowchart of Fig. 6(b) shows an example of the procedure for the cable specification-compliant communication setting process in step ST7 of the flowchart of Fig. 5. First, the control unit 102 starts the process in step ST21. Next, in step ST22, the control unit 102 sets the connected channel set to the used channel set or the available channel set based on the channel set connection status detected in the "communication setting 1" process, i.e., step ST12 of the flowchart of Fig. 6(a), and then ends the process in step ST23. Note that in step ST22, the control unit 102 may further perform power reduction processing for communications using a non-connected channel set based on the channel set connection status detected in step ST12 of the flowchart of Fig. 6(a).

[0071] This communication power reduction process includes not modulating light (High / Low) on the corresponding channel of the transmitter 105T, keeping the output level low, and even turning off the power to the corresponding channel, etc. These processes are possible because there is no need to communicate actual data (transmission data) such as images and audio using the non-connected channel set, and they reduce power consumption.

[0072] The flowchart of Fig. 7(a) shows another example of the procedure for the cable specification detection process in step ST6 of the flowchart of Fig. 5. In this example, the optical cable specification detection optical signal transmitted in step ST2 of the flowchart of Fig. 5 may be either the non-connected channel confirmation optical signal or the channel number identification optical signal described above.

[0073] First, the control unit 102 starts processing in step ST31. Next, in step ST32, the control unit 102 performs the "specification 1 detection" process, i.e., determines whether each channel set of the optical cable 300 is a connected channel set or a non-connected channel set, as in step ST12 of the flowchart in FIG. 6A, and detects the channel set connection status indicating whether each channel set is a connected channel set or a non-connected channel set as a specification of the optical cable 300.

[0074] Next, in step ST33, the control unit 102 performs the "specification 2 detection" process, i.e., monitors the reception status of return optical signals in the six receiving channels of the receiving unit 105R, from receiving channel 1 (rch1) to receiving channel 6 (rch6), determines the number of receiving channels that did not receive return optical signals as the number of connected channel sets, detects the number of connected channel sets as a specification of the optical cable 300, and then terminates the process in step ST34.

[0075] The flowchart of Fig. 7(b) shows another example of the procedure for the cable specification-compliant communication setting process in step ST7 of the flowchart of Fig. 5. First, the control unit 102 starts the process in step ST41. Next, in step ST42, similar to step ST22 of the flowchart of Fig. 6(b), the control unit 102 sets the connected channel set to the used channel set or the available channel set based on the channel set connection state detected in the "communication setting 1" process, i.e., step ST32 of the flowchart of Fig. 7(a), and also performs power reduction processing for communications using the non-connected channel set, as necessary.

[0076] Next, in step ST43, the control unit 102 processes "communication setting 2", i.e., sets communication settings, for example, the transmission bandwidth, based on the number of connection channel sets detected in step ST33 of the flowchart in Figure 7(a), and then terminates the processing in step ST44.

[0077] Setting of the transmission bandwidth will now be described. The control unit 102 sets the transmission bandwidth by referring to, for example, correspondence relationship information between the number of connected channel sets and the transmission bandwidth, as shown in FIG. 8, which is stored in the storage unit 107. For example, when the number of connected channel sets is 3, the transmission bandwidth is set to 3 / 6 * total transmission bandwidth [Gbps]. Here, the total transmission bandwidth indicates the transmission bandwidth that can be transmitted using all six channels, i.e., the transmission bandwidth. It is also possible that the control unit 102 refers to the correspondence relationship information between the number of connected channel sets and the transmission bandwidth from a cloud on the Internet (not shown).

[0078] The flowchart of Fig. 9(a) shows yet another example of the procedure of the cable specification detection process in step ST6 of the flowchart of Fig. 5. In this example, the optical cable specification detection optical signal transmitted in step ST2 of the flowchart of Fig. 5 is the above-mentioned channel number identification optical signal.

[0079] First, the control unit 102 starts processing in step ST51. Next, in step ST52, the control unit 102 performs the "specification 1 detection" process, i.e., determines whether each channel set of the optical cable 300 is a connected channel set or a non-connected channel set, as in step ST12 of the flowchart in FIG. 6A, and detects the channel set connection status indicating whether each channel set is a connected channel set or a non-connected channel set as a specification of the optical cable 300.

[0080] Next, in step ST53, the control unit 102 performs the "specification 2 detection" process, similar to step ST33 in the flowchart of Figure 7(a), i.e., monitors the reception status of return optical signals in the six receiving channels of the receiving unit 105R, from receiving channel 1 (rch1) to receiving channel 6 (rch6), determines the number of receiving channels that did not receive return optical signals as the number of connected channel sets, and detects the number of connected channel sets as a specification of the optical cable 300.

[0081] Next, in step ST54, the control unit 102 performs a "specification 3 detection" process, i.e., detects the specifications of the optical cable 300 based on the input / output channel connection relationship. The specifications include at least one of the optical wavelength, insertion loss, fiber type, total transmission bandwidth, and cable length.

[0082] In this case, the control unit 102 acquires the input / output channel connection relationship based on which transmission channel of the transmission unit 105T the return optical signal of which is received by the six reception channels, reception channel 1 (rch1) to reception channel 6 (rch6) of the reception unit 105R. In this case, the control unit 102 detects the specification of the optical cable 300 by referring to, for example, correspondence information between the input / output channel connection relationship and the specification of the optical cable 300 stored in the storage unit 107.

[0083] 10 shows an example of correspondence information between input / output channel connection relationships and the specifications of the optical cable 300, which is stored in the storage unit 107. In this example, for example, when the reception channel of reception channel 5 (rch5) is a return optical signal of the channel number identification optical signal of the transmission channel of transmission channel 5 (tch5), the optical wavelength in the specifications of the optical cable 300 is detected as "850 [nm]." Also, for example, when the reception channel of reception channel 6 (rch6) is a return optical signal of the channel number identification optical signal of the transmission channel of transmission channel 5 (tch5), the optical wavelength in the specifications of the optical cable 300 is detected as "1310 [nm]."

[0084] In this example, for example, when the signal received at the receiving channel of receiving channel 4 (rch4) is a return optical signal of the channel number identification optical signal of the transmitting channel of transmitting channel 4 (tch4), the insertion loss in accordance with the specifications of the optical cable 300 is detected as "less than 3 dB." Also, for example, when the signal received at the receiving channel of receiving channel 4 (rch4) is a return optical signal of the channel number identification optical signal of the transmitting channel of transmitting channel 6 (tch6), the insertion loss in accordance with the specifications of the optical cable 300 is detected as "3 to 6 dB."

[0085] In this example, for example, when the signal received at the receiving channel of receiving channel 3 (rch3) is a return optical signal of the channel number identification optical signal of the transmitting channel of transmitting channel 3 (tch3), the fiber type in the specifications of the optical cable 300 is detected as "MMF." Also, for example, when the signal received at the receiving channel of receiving channel 3 (rch3) is a return optical signal of the channel number identification optical signal of the transmitting channel of transmitting channel 2 (tch2), the fiber type in the specifications of the optical cable 300 is detected as "SMF."

[0086] If the plug 302 of the optical cable 300 has two unconnected channels, channel 6 (ch6) and channel 5 (ch5), the optical wavelength is detected as specified for the optical cable 300. If the plug 302 of the optical cable 300 has three unconnected channels, channel 6 (ch6) to channel 4 (ch4), the optical wavelength and insertion loss are detected as specified for the optical cable 300. If the plug 302 of the optical cable 300 has five unconnected channels, channel 6 (ch6) to channel 2 (ch2), the optical wavelength, insertion loss, and fiber type are detected as specified for the optical cable 300.

[0087] The correspondence relationship information between the input / output channel connection relationships and the specifications of the optical cable 300 shown in Fig. 10 is an example corresponding to the specification determination methods shown in Fig. 3(a), (b), and (c) described above. As described above, the specification determination methods shown in Fig. 3(a), (b), and (c) are designed so that the specification determination method in Fig. 3(a) can be commonly used with the specification determination methods in Fig. 3(b) and (c), and the specification determination method in Fig. 3(b) can also be used with the specification determination method in Fig. 3(c).

[0088] By determining the specifications independently for each channel depending on the number of unconnected channels, it is possible to incorporate more specification information, such as cable length, etc. Figure 11 shows an example of correspondence information between the input / output channel connection relationship and the specifications of the optical cable 300 when, for example, the number of unconnected channels is four.

[0089] In this example, for example, when the reception at reception channels 3 (rch3), 4 (rch4), 5 (rch5), and 6 (rch6) is a return optical signal of the channel number identification optical signal of transmission channel 3 (tch3), 4 (tch4), 5 (tch5), and 6 (tch6), respectively, the specifications of the optical cable 300 are detected as follows: fiber type is "MMF," insertion loss is "less than 3 [dB]," optical wavelength is "850 [nm]," and cable length is "less than 100 [m]."

[0090] Furthermore, in this example, when the reception at reception channels 3 (rch3), 4 (rch4), and 5 (rch5) is a return optical signal of the channel number identification optical signal of transmission channel 3 (tch3), 4 (tch4), and 6 (tch6), respectively, the specifications of the optical cable 300 are detected as follows: fiber type is "SMF," insertion loss is "3 to 6 [dB]," optical wavelength is "1310 [nm]," and cable length is "less than 100 [m]."

[0091] Furthermore, in this example, when the received optical signals at receiving channels 3 (rch3), 4 (rch4), and 6 (rch6) are return optical signals of the channel number identification optical signals of transmitting channels 3 (tch3), 5 (tch5), and 6 (tch6), respectively, the specifications of the optical cable 300 are detected as follows: fiber type is "MMF," insertion loss is "less than 3 dB," optical wavelength is "1310 nm," and cable length is "100 m or more."

[0092] It is also conceivable that the control unit 102 may refer to information on the correspondence between the input / output channel connection relationships and the specifications of the optical cable 300 from a cloud on the Internet (not shown).

[0093] The flowchart of Fig. 9(b) shows yet another example of the procedure for the cable specification-compliant communication setting process in step ST7 of the flowchart of Fig. 5. First, the control unit 102 starts the process in step ST61. Next, in step ST62, the control unit 102 performs the "communication setting 1" process, i.e., sets the connected channel set to the used channel set or the available channel set based on the channel set connection state detected in step ST52 of the flowchart of Fig. 9(a), similar to step ST22 of the flowchart of Fig. 6(b). If necessary, the control unit 102 also performs power reduction processing for communications using the non-connected channel set.

[0094] Next, in step ST63, the control unit 102 performs the "communication setting 2" process, similar to step ST43 in the flowchart of Figure 7(b), i.e., sets a communication setting, for example, a transmission bandwidth, based on the number of connection channel sets detected in step ST53 in the flowchart of Figure 9(a).

[0095] Next, in step ST64, the control unit 102 performs the "communication setting 3" process, i.e., in step ST54 of the flowchart of FIG. 9(a), performs communication setting based on at least one of the specifications of the optical cable 300, such as the optical wavelength, insertion loss, fiber type, total transmission bandwidth, and cable length, detected using, for example, the correspondence information between the input / output channel connection relationship and the specifications of the optical cable 300 (see FIGS. 10 and 11), and then ends the process in step ST65.

[0096] In this case, the control unit 102 sets, for example, the optical wavelength, the optical output level, etc. For example, the control unit 102 sets the optical wavelength of the device itself to match the specifications of the cable 300. Also, for example, the control unit 102 sets the optical output level of the device itself to compensate for the insertion loss in the specifications of the optical cable 300.

[0097] The flowchart in Fig. 12 shows another example of the processing procedure for detecting the specifications of the optical cable 300 in the control unit 102 of the device 100. In the flowchart in Fig. 12, steps corresponding to those in the flowchart in Fig. 5 are given the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0098] After the process of step ST6, the control unit 102 determines whether or not its own device is compatible with the specifications of the optical cable 300 in step ST8.

[0099] For example, in step ST6, if the control unit 102 detects a channel set connection state indicating whether each channel set of the optical cable 300 is a connected channel set or a non-connected channel set as a specification of the optical cable 300, the control unit 102 determines that the device 100 does not comply with the specification of the optical cable 300 when the device 100 cannot use the detected connected channel set.

[0100] Also, for example, when the control unit 102 detects the number of connection channel sets as a specification of the optical cable 300 in step ST6, if the detected number of connection channel sets is less than the number of connection channel sets that the device 100 can support, the control unit 102 determines that the device itself does not support the specification of the optical cable 300.

[0101] Furthermore, for example, in step ST6, if an optical wavelength is detected as a specification of the optical cable 300, and if the optical wavelength in the specification of the optical cable 300 does not match the optical wavelength that the device 100 can support, the control unit 102 determines that the device itself is not compatible with the specification of the optical cable 300. Furthermore, for example, in step ST6, if an insertion loss is detected as a specification of the optical cable 300, and if the insertion loss is d [dB], and if the optical output level of the device 100 cannot be increased by d [dBm] or more from the minimum optical output level required for communication, the control unit 102 determines that the device itself is not compatible with the specification of the optical cable 300.

[0102] If it is determined in step ST8 that the device itself is compatible with the cable specification, the control unit 102 proceeds to the processing of step ST7. On the other hand, if it is determined in step ST8 that the device itself is not compatible with the cable specification, the control unit 102 performs a cable specification non-compatibility warning process in step ST9, and then ends the processing in step ST5. In the cable specification non-compatibility warning process, for example, a message that the device itself is not compatible with the cable specification is displayed or output as audio, and a non-compatibility warning is issued to the user. In this case, in addition to the message that the device itself is not compatible with the cable specification, the reason for the non-compatibility and the specification of the optical cable 300 that should be replaced may also be displayed or output as audio.

[0103] FIG. 13 shows an example of the specifications of device (device A) 100 and the cable specifications that it can support. Here, examples of device A-1, device A-2, and device A-3 are shown as examples of the specifications of device (device A) 100. Note that in FIG. 13, "*1" indicates that the cable specifications are unknown, but the device 100 does not determine that the cable specifications are "incompatible" and proceeds to the next step (data transmission). Also, in FIG. 13, "*2" indicates that the total transmission bandwidth is 150 Gbps. Also, in FIG. 13, "OK" indicates that the cable specifications are determined to be "compatible."

[0104] An example of device A-1 will be described below, which has specifications of an optical wavelength of 850 nm, a maximum output of 0 dBm, and a transmission bandwidth of 25 Gbps.

[0105] Consider a case where the number of connected channel sets is 6 or 5, and none of the optical wavelength, insertion loss, or fiber type is detected as a specification of the optical cable 300. In this case, as a specification of the optical cable 300, when the number of connected channel sets is 6, the possible transmission bandwidth is detected as "150 [Gbps]", and when the number of connected channel sets is 5, the possible transmission bandwidth is detected as "125 [Gbps]". In this case, device A-1 does not determine that the device is incompatible, and proceeds to the next step (data transmission).

[0106] Next, consider a case where the number of connected channel sets is four and an optical wavelength is detected as a specification of the optical cable 300. In this case, the transmittable bandwidth is further detected as "100 Gbps" as a specification of the optical cable 300. In this case, device A-1 determines that the optical wavelength is compatible (OK) when it is "850 nm," but determines that the optical wavelength is not compatible when it is "1310 nm" because the optical wavelength does not match.

[0107] Next, consider a case where the number of connected channel sets is 3, and the optical wavelength and insertion loss are detected as specifications of the optical cable 300. In this case, the transmittable bandwidth is further detected as the specifications of the optical cable 300 as "75 Gbps." In this case, device A-1 determines that the optical cable is compatible (OK) if the optical wavelength is "850 nm" and the insertion loss is "less than 3 dB," and otherwise determines that the optical cable is not compatible.

[0108] Next, consider a case where the number of connected channel sets is two and the optical wavelength and insertion loss are detected as specifications of the optical cable 300. In this case, the transmittable bandwidth is further detected as "50 Gbps" as specifications of the optical cable 300. In this case, device A-1 determines that the optical cable is compatible (OK) if the optical wavelength is "850 nm" and the insertion loss is "less than 3 dB," and otherwise determines that the optical cable is not compatible.

[0109] Next, consider a case where the number of connected channel sets is 1, and the optical wavelength, insertion loss, and fiber type are detected as specifications of the optical cable 300. In this case, the transmittable bandwidth is further detected as the specifications of the optical cable 300 as "25 Gbps." In this case, device A-1 determines that the optical cable is compatible (OK) when the optical wavelength is "850 nm," the insertion loss is "less than 3 dB," and the fiber type is "MMF," and when the optical wavelength is "850 nm," the insertion loss is "less than 3 dB," and the fiber type is "SMF," but determines that the optical cable is not compatible in any other cases.

[0110] An example of device A-2 will be described below, which has specifications of an optical wavelength of 850 nm, a maximum output of 0 dBm, and a transmission bandwidth of 50 Gbps.

[0111] Consider a case where the number of connected channel sets is 6 or 5, and none of the optical wavelength, insertion loss, and fiber type are detected as specifications of the optical cable 300. In this case, as specifications of the optical cable 300, when the number of connected channel sets is 6, the possible transmission bandwidth is detected as "150 [Gbps]", and when the number of connected channel sets is 5, the possible transmission bandwidth is detected as "125 [Gbps]". In this case, device A-2 does not determine that the device is incompatible, and proceeds to the next step (data transmission).

[0112] Next, consider a case where the number of connected channel sets is four and an optical wavelength is detected as a specification of the optical cable 300. In this case, the transmittable bandwidth is further detected as "100 Gbps" as a specification of the optical cable 300. In this case, device A-2 determines that it is compatible (OK) when the optical wavelength is "850 nm", and determines that it is not compatible when the optical wavelength is "1310 nm".

[0113] Next, consider a case where the number of connected channel sets is 3, and the optical wavelength and insertion loss are detected as specifications of the optical cable 300. In this case, the transmittable bandwidth is further detected as the specifications of the optical cable 300 as "75 Gbps." In this case, device A-2 determines that the optical cable is compatible (OK) if the optical wavelength is "850 nm" and the insertion loss is "less than 3 dB," and determines that the optical cable is not compatible in any other cases.

[0114] Next, consider a case where the number of connected channel sets is two and the optical wavelength and insertion loss are detected as specifications of the optical cable 300. In this case, the transmittable bandwidth is further detected as "50 Gbps" as specifications of the optical cable 300. In this case, device A-2 determines that the optical cable is compatible (OK) if the optical wavelength is "850 nm" and the insertion loss is "less than 3 dB," and otherwise determines that the optical cable is not compatible.

[0115] Next, consider a case where the number of connected channel sets is 1, and the optical wavelength, insertion loss, and fiber type are detected as specifications of the optical cable 300. In this case, the available transmission bandwidth is further detected as "25 Gbps" as specifications of the optical cable 300. In this case, device A-2 determines that it cannot support the optical cable 300 because the available transmission bandwidth is too small.

[0116] An example of device A-3 will be described below, which has specifications of an optical wavelength of 1310 nm, a maximum output of +3 dBm, and a transmission bandwidth of 75 Gbps.

[0117] Consider a case where the number of connected channel sets is 6 or 5, and none of the optical wavelength, insertion loss, and fiber type are detected as specifications of the optical cable 300. In this case, as specifications of the optical cable 300, when the number of connected channel sets is 6, the possible transmission bandwidth is detected as "150 [Gbps]", and when the number of connected channel sets is 5, the possible transmission bandwidth is detected as "125 [Gbps]". In this case, device A-3 does not determine that the device is incompatible, and proceeds to the next step (data transmission).

[0118] Next, consider a case where the number of connected channel sets is four and an optical wavelength is detected as a specification of the optical cable 300. In this case, the transmittable bandwidth is further detected as "100 [Gbps]" as a specification of the optical cable 300. In this case, device A-3 determines that it is compatible (OK) when the optical wavelength is "1310 [nm]", and determines that it is not compatible when the optical wavelength is "850 [nm]".

[0119] Next, consider a case where the number of connected channel sets is three and the optical wavelength and insertion loss are detected as specifications of the optical cable 300. In this case, the transmittable bandwidth is further detected as specifications of the optical cable 300 as "75 Gbps." In this case, device A-3 determines that the optical cable is compatible (OK) when the optical wavelength is "1310 nm" and the insertion loss is "less than 3 dB," or when the optical wavelength is "1310 nm" and the insertion loss is "3 to 6 dB," but determines that the optical cable is not compatible in any other cases.

[0120] Next, consider a case where the number of connected channel sets is two and the optical wavelength and insertion loss are detected as specifications of the optical cable 300. In this case, the available transmission bandwidth is further detected as "50 Gbps" as specifications of the optical cable 300. In this case, device A-3 determines that it cannot support the transmission bandwidth because the available transmission bandwidth is too small.

[0121] Next, consider a case where the number of connected channel sets is 1, and the optical wavelength, insertion loss, and fiber type are detected as specifications of the optical cable 300. In this case, the available transmission bandwidth is further detected as "25 Gbps" as specifications of the optical cable 300. In this case, device A-3 determines that it cannot support the optical cable 300 because the available transmission bandwidth is too small.

[0122] "1-1-2-2. Other Processing Procedures, Such as Device Specification Detection" The flowchart in Fig. 14 shows an example of a processing procedure, such as specification detection of the optical cable 300, in the control unit 102 of the device 100. This example is an example in which damage to the optical cable 300 can also be detected. In the flowchart in Fig. 14, steps corresponding to those in the flowchart in Fig. 12 are given the same reference numerals, and detailed explanations thereof will be omitted as appropriate.

[0123] The control unit 102 of the device (device A) 100 starts processing in step ST1. Next, the control unit 102 of the device (device A) 100 transmits optical cable specification detection signals in step ST2. In this case, the optical cable specification detection signals are input from six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6), of the transmitter 105T to six transmission channels, transmission channel 1 (tch1) to transmission channel 6 (tch6) of the plug 302 of the optical cable 300.

[0124] Next, in step ST3, the control unit 102 of the device (device A) 100 determines whether or not an optical cable specification detection optical signal has been received as a return optical signal. In this case, the control unit 102 monitors the reception status of return optical signals (here, whether or not a return optical signal has been received) in six reception channels, from reception channel 1 (rch1) to reception channel 6 (rch6) of the receiving unit 105R, and determines that an optical cable specification detection optical signal has been received as a return optical signal when an optical cable specification detection optical signal has been received in any of the reception channels; otherwise, it determines that an optical cable specification detection optical signal has not been received as a return optical signal.

[0125] When it is determined that an optical cable specification detection optical signal has not been received as a return optical signal, the control unit 102 of the device (device A) 100 sets all channel sets as used channel sets or available channel sets in step ST4, and then terminates the processing in step ST5.

[0126] When it is determined in step ST3 that an optical cable specification detection optical signal has been received as a return optical signal, the control unit 102 performs a cable specification detection process in step ST6, and then determines in step ST8 whether its own device is compatible with the specifications of the optical cable 300.

[0127] If it is determined in step ST8 that the device itself is not compatible with the cable specification, the control unit 102 performs a cable specification non-compatibility warning process in step ST9, and then ends the process in step ST5. On the other hand, if it is determined in step ST8 that the device itself is compatible with the cable specification, the control unit 102 proceeds to the process of step ST81.

[0128] In step ST81, the control unit 102 of the device (device A) 100 transmits a cable breakage confirmation optical signal to the device (device B) 200 using the connection transmission channel of the optical cable 300. This cable breakage confirmation optical signal is the same optical signal as the optical cable specification detection optical signal in step ST2 described above.

[0129] The control unit 202 of the device (device B) 200 starts processing in step ST71. Next, in step ST72, the control unit 202 of the device (device B) 200 receives a cable breakage confirmation optical signal from the device (device A) 100 on the connection reception channel. Next, in step ST73, the control unit 202 of the device (device B) 200 transmits a cable breakage confirmation response optical signal to the device (device A) 100 using the connection transmission channel corresponding to the connection reception channel that received the cable breakage confirmation optical signal. Thereafter, the control unit 202 of the device (device B) 200 ends processing in step ST74.

[0130] After the process of step ST81, the control unit 102 of the device (device A) 100 receives a cable breakage confirmation response optical signal from the device (device B) 200 on the connection receiving channel in step ST82.

[0131] Next, in step ST83, the control unit 102 of the device (device A) 100 determines whether the number of transmission channels of the cable breakage confirmation optical signal matches the number of reception channels of the cable breakage confirmation response optical signal. If they do not match, the control unit 102 of the device (device A) 100 determines that the optical cable 300 is damaged, performs a cable breakage warning process in step ST84, and then ends the process in step ST5. In the cable breakage warning process, for example, a message that the optical cable 300 is damaged is displayed or output as an audio message to warn the user of the cable breakage.

[0132] If it is determined in step ST83 that the two match, the control unit 102 of the device (device A) 100 proceeds to step ST7. In step ST7, the control unit 102 of the device (device A) 100 performs a cable specification compatible communication setting process, and then ends the process in step ST5.

[0133] In this way, by executing the process shown in the flowchart of Figure 14, the control unit 102 of the device 100 can detect the specifications of the optical cable 300 and perform communication settings corresponding to those specifications, as well as detect damage to the optical cable 300.

[0134] The flowchart in Fig. 15 shows another example of the processing procedure for specification detection, etc. in the control unit 102 of the device 100, which is also an example that can detect breakage in the optical cable 300. In the flowchart in Fig. 15, steps corresponding to those in the flowchart in Fig. 14 are given the same reference numerals, and detailed explanations thereof will be omitted as appropriate.

[0135] In this example, the control unit 102 of the device (device A) 100 proceeds to step ST83A after processing step ST82. In step ST83A, the control unit 102 of the device (device A) 100 determines whether the transmission channel number of the cable breakage confirmation optical signal and the reception channel number of the cable breakage confirmation response optical signal match. If they do not match, that is, if the connection channel set has a channel number that is present in the transmission channel number but not in the reception channel number, it can be determined that the connection channel set is damaged.

[0136] If the control unit 102 of the device (device A) 100 determines that the specifications match, it performs a cable specification compatible communication setting process in step ST7, and then ends the process in step ST5. On the other hand, if it determines that the specifications do not match, it performs a cable breakage warning process in step ST84, and then ends the process in step ST5. In the cable breakage warning process, for example, a message that the optical cable 300 is broken and which connection channel set is broken are displayed or output as audio, and the user is warned of the cable breakage.

[0137] In this way, by executing the process shown in the flowchart of Figure 15, the control unit 102 of the device 100 can detect the specifications of the optical cable 300 and perform communication settings corresponding to those specifications, as well as detect damage to the optical cable 300 (which connection channel set is damaged).

[0138] As described above, the optical communication system 10 shown in FIG. 1 has an optical return mechanism 321 (optical return mechanism 331) that outputs an incident optical signal that is transmitted from one of a plurality of transmission channels of the transmitter 105T (transmitter 205T) of the device 100 (device 200) and input to an unconnected transmission channel via the plug 302 (plug 303), as a return optical signal, from an unconnected reception channel included in an unconnected channel set that includes the unconnected transmission channel, toward the receiver 105R (receiver 205R) of the device 100 (device 200) via the plug 302 (plug 303). This makes it possible for the device 100 (device 200) to detect the specifications of the optical cable 300 depending on the reception status at the receiver 105R (receiver 205R).

[0139] "1-1-3. Processing by Software" The processing shown in each of the flowcharts above can be executed by hardware, but can also be executed by software. When a series of processes is executed by software, the programs that make up the software are installed from a recording medium into a computer that is built into dedicated hardware, or into, for example, a general-purpose computer that can execute various functions by installing various programs.

[0140] 16 is a block diagram showing an example of the hardware configuration of a computer 600. The computer 600 has a CPU 601, a ROM 602, a RAM 603, a bus 604, an input / output interface 605, an input unit 606, an output unit 607, a storage unit 608, a drive 609, a connection port 610, and a communication unit 611. Note that the hardware configuration shown here is an example, and some of the components may be omitted. Furthermore, the computer 600 may further include components other than those shown here.

[0141] The CPU 601 functions as, for example, an arithmetic processing device or a control device, and controls the overall operation or part of the operation of each component based on various programs recorded in the ROM 602 , the RAM 603 , the storage unit 608 , or the removable recording medium 701 .

[0142] The ROM 602 is a means for storing programs to be read into the CPU 601, data to be used for calculations, etc. The RAM 603 temporarily or permanently stores, for example, the programs to be read into the CPU 601 and various parameters that change as appropriate when the programs are executed.

[0143] The CPU 601, ROM 602, and RAM 603 are connected to one another via a bus 604. On the other hand, various components are connected to the bus 604 via an input / output interface 605.

[0144] The input unit 606 may be, for example, a mouse, a keyboard, a touch panel, a button, a switch, a lever, etc. Furthermore, the input unit 606 may also be a remote controller (hereinafter referred to as a remote control) that is capable of transmitting control signals using infrared rays or other radio waves.

[0145] The output unit 607 is a device capable of visually or audibly notifying the user of acquired information, such as a display device such as a CRT (Cathode Ray Tube), LCD, or organic EL, an audio output device such as a speaker or headphones, a printer, a mobile phone, or a facsimile.

[0146] The storage unit 608 is a device for storing various types of data. For example, the storage unit 608 may be a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, or a magneto-optical storage device.

[0147] The drive 609 is a device that reads information recorded on a removable recording medium 701 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, or writes information to the removable recording medium 701 .

[0148] The removable recording medium 701 is, for example, a DVD, a Blu-ray (registered trademark) disc, an HD DVD, various semiconductor storage media, etc. Of course, the removable recording medium 701 may also be, for example, an IC card equipped with a contactless IC chip, an electronic device, etc.

[0149] The connection port 610 is a port for connecting an external device 502, such as a Universal Serial Bus (USB) port, a High-Definition Multimedia Interface (HDMI) port, an IEEE 1394 port, a Small Computer System Interface (SCSI), an RS-232C port, or an optical audio terminal. Here, "HDMI" is a registered trademark. The external device 702 is, for example, a printer, a portable music player, a digital camera, a digital video camera, or an IC recorder.

[0150] The communication unit 611 is a communication device for connecting to the network 703, such as a communication card for wired or wireless LAN, Bluetooth (registered trademark), or WUSB (Wireless USB), a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), or a modem for various types of communication.

[0151] The program executed by the computer may be a program that processes in chronological order according to the order described in this specification, or may be a program that processes in parallel or at the required timing, such as when called.

[0152] 2. Modifications Although preferred embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the present disclosure can conceive of various modified or altered examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0153] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that will be apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0154] The present technology may also be configured as follows: (1) An optical communication device comprising: a receptacle, a transmitter having a plurality of transmission channels, a receiver having a plurality of reception channels, a plug configured to be able to fit with the receptacle, one or more connection channel sets including a connection transmission channel and a connection reception channel corresponding to the connection transmission channel, one or more unconnected channel sets including an unconnected transmission channel and an unconnected reception channel corresponding to the unconnected transmission channel, and an optical return mechanism that causes an incident optical signal transmitted from any of the plurality of transmission channels of the transmitter and incident on the unconnected transmission channel via the plug to be output as a return optical signal from the unconnected reception channel included in the unconnected channel set including the unconnected transmission channel via the plug, and a control unit that detects the specification of the optical cable in accordance with a reception status of the return optical signal from the optical cable at the receiver. (2) The optical communication device described in (1), wherein the control unit detects, as the specification, a channel set connection state indicating whether each of the input / output channel sets consisting of the receiving channels and the transmitting channels corresponding to the receiving channels is the connected channel set or the unconnected channel set, based on whether each receiving channel of the receiving unit has received the returned optical signal. (3) The optical communication device described in (2), wherein the control unit sets the connected channel set as a used channel set or an available channel set. (4) The optical communication device described in (2) or (3), wherein the control unit performs power reduction processing for communication using the unconnected channel set. (5) The optical communication device described in any of (1) to (4), wherein the control unit detects the number of connected channel sets as a specification of the optical cable depending on the number of receiving channels among the plurality of receiving channels that receive the returned optical signal from the plug of the optical cable. (6) The control unit detects the specifications of the optical cable based on an input / output channel connection relationship indicating which receiving channel of the transmitting unit receives a return optical signal of the optical signal of which transmitting channel of the transmitting unit. The optical communication device described in any one of (1) to (5).(7) The optical communication device described in (6), wherein the transmitter emits an optical signal from which a channel number can be identified from at least some of the multiple transmission channels. (8) The optical communication device described in any of (1) to (7), wherein the control unit performs settings related to optical communication to conform to the specifications of the optical cable. (9) The optical communication device described in any of (1) to (8), wherein the control unit performs a warning process when the specifications of the optical cable cannot be met. (10) The optical communication device described in any of (1) to (9), wherein the control unit determines whether the optical cable is damaged based on a cable damage confirmation response optical signal transmitted from an external device connected via the optical cable in response to a cable damage confirmation optical signal transmitted via the connected transmission channel to the external device and received by the receiver. (11) The optical communication device described in (10), wherein the control unit determines whether the optical cable is damaged when the number of receiving channels indicated by the cable damage confirmation response optical signal does not match the number of connected transmitting channels. (12) The optical communication device according to (10), wherein, when a receiving channel number indicated by the cable breakage confirmation response optical signal does not match a channel number of the connected transmitting channel, the control unit determines that an input / output channel set of the optical cable corresponding to the connected transmitting channel whose channel number does not match is damaged. (13) The optical communication device according to any one of (10) to (12), wherein the control unit performs a warning process when it determines that the optical cable is damaged. (14) An optical cable comprising: a plug configured to be able to mate with a receptacle of an optical communication device; one or more connection channel sets including a connection transmitting channel and a connection receiving channel corresponding to the connection transmitting channel; one or more non-connection channel sets including a non-connection transmitting channel and a non-connection receiving channel corresponding to the non-connection transmitting channel; and an optical return mechanism that outputs an incident optical signal transmitted from one of a plurality of transmitting channels of a transmitting section of the optical communication device and input to the non-connection transmitting channel via the plug from a non-connection receiving channel included in the non-connection channel set including the non-connection transmitting channel as a return optical signal toward a receiving section of the optical communication device via the plug.(15) The optical cable according to (14), wherein the light return mechanism has an input / output channel connection relationship changing mechanism for outputting an incident optical signal input to each of the unconnected transmitting channels from one of the unconnected receiving channels based on an input / output channel connection relationship according to the specifications of the optical cable. (16) The optical cable according to (15), wherein the specifications of the optical cable include at least one of a channel set connection state indicating whether each channel set of the optical cable is a connected channel set or an unconnected channel set, the number of connected channel sets, an optical wavelength, an insertion loss, a fiber type, a total transmission bandwidth, and a cable length. (17) The optical cable according to any of (14) to (16), wherein the light return mechanism is configured using a mirror. (18) The optical cable according to any of (14) to (16), wherein the light return mechanism is configured using an optical waveguide. (19) The optical cable according to any of (14) to (18), wherein the plugs are provided at both ends of the optical cable main body. (20) An optical communication system comprising an optical communication device and an optical cable connected to the optical communication device, the optical cable having: a plug configured to be able to mate with a receptacle of the optical communication device; one or more connection channel sets including a connection transmitting channel and a connection receiving channel corresponding to the connection transmitting channel; one or more non-connection channel sets including a non-connection transmitting channel and a non-connection receiving channel corresponding to the non-connection transmitting channel; and an optical return mechanism that causes an incident optical signal transmitted from one of a plurality of transmitting channels of a transmitting section of the optical communication device and input to the non-connection transmitting channel via the plug to be output as a return optical signal from a non-connection receiving channel included in the non-connection channel set including the non-connection transmitting channel towards a receiving section of the optical communication equipment via the plug, and the optical communication device comprising: the receptacle; the transmitting section having a plurality of transmitting channels; the receiving section having a plurality of receiving channels; and a control section that detects the specifications of the optical cable according to the reception status of the return optical signal from the optical cable at the receiving section.

[0155] 10... Optical communication system 100... Device (Device A) 101... Receptacle 102... Control unit 103... Communication signal input / output unit 104... Signal processing unit 105T... Transmitting unit 105R... Receiving unit 106... Presentation unit 107... Memory unit 200... Device (Device B) 201... Receptacle 202... Control unit 203... Communication signal input / output unit 204... Signal processing unit 205T... Transmitting unit 205R... Receiving unit 206... Presentation unit 207... Memory unit 300... Optical cable 301... Optical cable main body 302, 303... Plug 321, 331... Light return mechanism 321a... First mirror 321b... Second mirror 321c... Optical waveguide

Claims

1. An optical communications device comprising: a receptacle; a transmitting unit having a plurality of transmitting channels; a receiving unit having a plurality of receiving channels; a plug configured to be able to fit with the receptacle; one or more connected channel sets including a connected transmitting channel and a connected receiving channel corresponding to the connected transmitting channel; one or more unconnected channel sets including an unconnected transmitting channel and an unconnected receiving channel corresponding to the unconnected transmitting channel; and an optical return mechanism for causing an incident optical signal transmitted from any of the plurality of transmitting channels of the transmitting unit and inputted into the unconnected transmitting channel via the plug to be outputted as a return optical signal via the plug from the unconnected receiving channel included in the unconnected channel set including the unconnected transmitting channel; and a control unit that detects the specifications of the optical cable in accordance with the reception status of the return optical signal from the optical cable in the receiving unit.

2. The optical communication device of claim 1, wherein the control unit detects, as the specification, a channel set connection state indicating whether each of the input / output channel sets consisting of each of the receiving channels and each of the receiving channels and the corresponding transmitting channel is a connected channel set or a non-connected channel set based on whether each of the receiving channels of the receiving unit has received the return optical signal.

3. The optical communication device according to claim 2, wherein the control unit sets the connected channel set as a used channel set or an available channel set.

4. The optical communication device according to claim 2, wherein the control unit performs power reduction processing for communication using the unconnected channel set.

5. The optical communication device according to claim 1, wherein the control unit detects the number of connection channel sets as a specification of the optical cable according to the number of receiving channels among the plurality of receiving channels that receive the return optical signal from the plug of the optical cable.

6. The optical communication device according to claim 1, wherein the control unit detects the specifications of the optical cable based on an input / output channel connection relationship indicating which receiving channel of the transmitting unit receives a return optical signal of the optical signal of which transmitting channel of the transmitting unit.

7. The optical communication device according to claim 6, wherein the transmitting section emits optical signals capable of identifying channel numbers from at least some of the plurality of transmitting channels.

8. The optical communications device according to claim 1, wherein the control unit performs settings related to optical communications so as to conform to the specifications of the optical cable.

9. The optical communication device according to claim 1, wherein the control unit performs a warning process when the specifications of the optical cable cannot be met.

10. The optical communication device of claim 1, wherein the control unit determines whether the optical cable is broken based on a cable breakage confirmation response optical signal transmitted from the external device connected via the optical cable in response to a cable breakage confirmation optical signal transmitted via the connection transmission channel to the external device and received by the receiving unit.

11. The optical communication device according to claim 10, wherein the control unit determines that the optical cable is broken when the number of receiving channels indicated by the cable breakage confirmation response optical signal does not match the number of connected transmitting channels.

12. The optical communication device described in claim 10, wherein when the receiving channel number indicated by the cable breakage confirmation response optical signal does not match the channel number of the connected transmitting channel, the control unit determines that the input / output channel set of the optical cable corresponding to the connected transmitting channel with the mismatched channel number is damaged.

13. The optical communication device according to claim 10, wherein the control unit performs a warning process when it is determined that the optical cable is damaged.

14. An optical cable comprising: a plug configured to be able to mate with a receptacle of an optical communication device; one or more connection channel sets including a connection transmitting channel and a connection receiving channel corresponding to the connection transmitting channel; one or more non-connection channel sets including a non-connection transmitting channel and a non-connection receiving channel corresponding to the non-connection transmitting channel; and an optical return mechanism that causes an incident optical signal transmitted from one of a plurality of transmitting channels of a transmitting section of the optical communication device and input to the non-connection transmitting channel via the plug to be output as a return optical signal from a non-connection receiving channel included in the non-connection channel set including the non-connection transmitting channel towards the receiving section of the optical communication device via the plug.

15. The optical cable according to claim 14, wherein the optical return mechanism has an input / output channel connection relationship change mechanism for outputting an incident optical signal input to each of the non-connected transmitting channels from one of the non-connected receiving channels based on an input / output channel connection relationship according to the specifications of the optical cable.

16. The optical cable according to claim 15, wherein the specifications of the optical cable include at least one of a channel set connection state indicating whether each channel set of the optical cable is a connected channel set or a non-connected channel set, the number of connected channel sets, an optical wavelength, an insertion loss, a fiber type, a total transmission bandwidth, and a cable length.

17. The optical cable according to claim 14, wherein the light return mechanism is configured using a mirror.

18. The optical cable according to claim 14, wherein the light return mechanism is configured using an optical waveguide.

19. The optical cable according to claim 14, wherein the plugs are provided on both ends of the optical cable body.

20. An optical communications system comprising: an optical communications device; and an optical cable connected to the optical communications device, the optical cable having: a plug configured to be able to fit into a receptacle of the optical communications device; one or more connected channel sets including a connected transmitting channel and a connected receiving channel corresponding to the connected transmitting channel; one or more unconnected channel sets including an unconnected transmitting channel and an unconnected receiving channel corresponding to the unconnected transmitting channel; and an optical return mechanism that causes an incident optical signal transmitted from any of a plurality of transmitting channels of a transmitting section of the optical communications device and input to the unconnected transmitting channel via the plug to be output as a return optical signal from an unconnected receiving channel included in the unconnected channel set including the unconnected transmitting channel, towards a receiving section of the optical communications equipment via the plug, the optical communications device comprising: the receptacle; the transmitting section having a plurality of transmitting channels; the receiving section having a plurality of receiving channels; and a control section that detects the specifications of the optical cable depending on the reception status of the return optical signal from the optical cable at the receiving section.

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