WO2024232012A1 - Communication control device, communication control method, and program - Google Patents

Abstract

A communication control device according to one embodiment of the present invention controls communication of an optical communication system. The optical communication system comprises: a first termination device; a second termination device; a first splitter that branches an optical signal from the first termination device; a second splitter that branches an optical signal from the second termination device; a plurality of third termination devices; a switching device that is provided between the plurality of third termination devices and the first and second splitters and that is configured to execute a switching operation for switching communication of at least one third termination device with the first termination device via the first splitter to communication with the second termination device via the second splitter; and a communication control device. The communication control device comprises: an acquisition unit that acquires usage statuses of communication by the plurality of third termination devices via the first splitter and the second splitter; a selection unit that selects a switching target from the plurality of third termination devices on the basis of the acquired usage statuses; and an instruction unit that instructs the switching device to execute the switching operation for the selected switching target.

Description

COMMUNICATION CONTROL DEVICE, COMMUNICATION CONTROL METHOD, AND PROGRAM

The embodiments relate to a communication control device, a communication control method, and a program.

PON (passive optical network) is known as an optical communications system that uses optical lines. In PON, optical signals are branched and merged using an optical splitter, a low-cost passive element, without optical-electrical conversion. In PON, a single optical cable connects an OLT (optical line terminal), which is the terminal device on the station side, and multiple ONUs (optical network units), which are the terminal devices on the user side, via an optical splitter.

It is preferable to allocate equal bandwidth to multiple ONUs. For this reason, technology has been proposed to allocate equal bandwidth to multiple ONUs that belong to (are accommodated in) the same PON.

JP 2012-19353 A

However, the number of ONUs accommodated may differ between different PONs. Furthermore, the traffic volume of each of the multiple ONUs may differ from one another. For this reason, it is difficult to equalize the bandwidth allocated to ONUs between different PONs.

The present invention was made with the above in mind, and its purpose is to provide a means to equalize the bandwidth allocated to ONUs across different PONs.

A communication control device according to one embodiment controls communication in an optical communication system. The optical communication system includes a first terminal device, a second terminal device, a first splitter that splits an optical signal from the first terminal device, a second splitter that splits an optical signal from the second terminal device, a plurality of third terminal devices, a switching device provided between the first splitter and the second splitter and the plurality of third terminal devices and configured to execute a switching operation for switching communication between at least one of the plurality of third terminal devices and the first terminal device via the first splitter to communication between the second terminal device and the first terminal device via the second splitter, and the communication control device. The communication control device includes an acquisition unit that acquires a usage status of communication via the first splitter and the second splitter by the plurality of third terminal devices, a selection unit that selects a switching target from the plurality of third terminal devices based on the acquired usage status, and an instruction unit that instructs the switching device to execute the switching operation for the selected switching target.

According to the embodiment, a means can be provided for leveling out the bandwidth allocated to ONUs across different PONs.

FIG. 1 is a block diagram illustrating an example of an optical communication system according to an embodiment. FIG. 2 is a block diagram showing an example of a configuration of a portion including a switching device in an optical communication system according to an embodiment. FIG. 3 is a block diagram illustrating an example of a hardware configuration of the communication control device according to the embodiment. FIG. 4 is a block diagram illustrating an example of a functional configuration of the communication control device according to the embodiment. FIG. 5 is a diagram illustrating an example of a data structure of a communication usage status DB used in the optical communication system according to the embodiment. FIG. 6 is a flowchart illustrating an example of a series of processes including a switching operation in the optical communication system according to the embodiment. FIG. 7 is a flowchart illustrating an example of a switching target selection process included in the switching operation in the optical communication system according to the embodiment.

The following describes the embodiments with reference to the drawings. In the following description, components having the same functions and configurations are given the same reference symbols.

1. Configuration 1.1 Optical communication system First, the configuration of the optical communication system according to the embodiment will be described. Fig. 1 is a block diagram showing an example of the configuration of the optical communication system according to the embodiment. The optical communication system 1 is an optical communication network including a communication control device 5 and multiple PONs (PON1 and PON2).

The communication control device 5 is, for example, a server installed in a telecommunications carrier's station. The communication control device 5 is configured to control the operation of multiple PONs.

PON1 and PON2 are passive optical networks. PON1 and PON2 provide information to users via the network NW. The number of users to which each of PON1 and PON2 provides information is arbitrary, but may be 32, for example.

1, PON1 includes OLT 11, SPa 21, multiple SPbs 31, 32, 33, and 34, multiple ONUs 41<1: _N1 >, 42<1: _N2 >, 43<1: _N3 >, and 44<1: _N4 >, and a part of switching device 50 (1≦ _N1 to _N4 ≦8). Also, in the example of FIG1, PON2 includes OLT 12, SPa 22, multiple SPbs 35, 36, 37, and 38, multiple ONUs 45<1: _N5 >, 46<1: _N6 >, 47<1: _N7 >, and 48<1: _N8 >, and a part of switching device 50 (1≦ _N5 to N8≦ ₈ ). Note that the plurality of ONUs 45<1:Nx> refers to Nx ONUs 45<1>, . . . , and 45<Nx> (x is an integer).

OLT11 and OLT12 are each optical line termination devices installed within a telecommunications carrier's office.

OLT11 controls the communication of information between network NW and PON1. OLT11 is connected to SPa21 via an optical cable.

OLT12 controls the communication of information between network NW and PON2. OLT12 is connected to SPa22 via an optical cable.

Each of SPa21 and SPa22 is a passive element that does not require a power source. Each of SPa21 and SPa22 is, for example, an optical splitter with a maximum of four branches.

The SPa21 branches the optical signal received from the OLT11. The optical signals branched by the SPa21 are transmitted to the switching device 50 via four different optical cables. The SPa21 also merges the four types of optical signals transmitted from the switching device 50 via the four different optical cables. The optical signals merged by the SPa21 are transmitted to the OLT11 via a single optical cable.

The SPa 22 branches the optical signal received from the OLT 12. The optical signals branched by the SPa 22 are transmitted to the switching device 50 via four different optical cables. The SPa 22 also merges the four types of optical signals transmitted from the switching device 50 via the four different optical cables. The optical signal merged by the SPa 22 is transmitted to the OLT 12 via one optical cable. Note that the number of optical cables that the SPa 22 branches and merges is not limited to four, and any integer equal to or greater than two may be applied.

Each of SPb31-38 is a passive element that does not require a power source. Each of SPb31-38 is, for example, an optical splitter with up to eight branches. Each of SPb31-38 branches the optical signal received from the switching device 50.

The optical signals branched by SPb31 are transmitted to ONU41<1:N ₁ > via N ₁ different optical cables. SPb31 also combines _{N 1 types} of optical signals transmitted from ONU41<1:N ₁ > via N 1 different optical cables. The optical signals combined by SPb31 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 32 are transmitted to ONU 42<1:N ₂ > via N ₂ different optical cables. SPb 32 also combines N ₂ types of optical signals transmitted from ONU 42<1:N ₂ > via N 2 different optical cables. The optical signals combined by _SPb 32 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 33 are transmitted to ONU 43<1: _N3 > via _N3 different optical cables. SPb 33 also combines _{N3 types} of optical signals transmitted from ONU 43<1: _N3 > via N3 different optical cables. The optical signals combined by SPb 33 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 34 are transmitted to ONUs 44<1: _N4 > via N4 different optical cables. SPb 34 also combines _N4 types of _optical signals transmitted from ONUs 44<1: _N4 > via _N4 different optical cables. The optical signals combined by SPb 34 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 35 are transmitted to ONU 45<1: _N5 > via N5 different optical cables. SPb 35 also combines _N5 types of optical signals transmitted from ONU 45<1: _N5 > via _N5 different optical cables. _The optical signals combined by SPb 35 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 36 are transmitted to ONUs 46<1: _N6 > via N6 different optical cables. SPb 36 also combines _N6 types of _optical signals transmitted from ONUs 46<1: _N6 > via _N6 different optical cables. The optical signals combined by SPb 36 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 37 are transmitted to ONU 47<1: _N7 > via N7 different optical cables. SPb 37 also combines _N7 types of optical signals transmitted from ONU 47<1: _N7 > via _N7 different optical cables. _The optical signals combined by SPb 37 are transmitted to the switching device 50 via one optical cable.

The optical signals branched by SPb 38 are transmitted to ONUs 48<1:N ₈ > via N ₈ different optical cables. SPb 38 also combines N ₈ types of optical signals transmitted from ONUs 48<1:N ₈ > via N 8 different optical cables. The optical signals combined by _SPb 38 are transmitted to the switching device 50 via one optical cable.

Each of the ONUs 41<1:N ₁ > to 44<1:N ₈ > is an optical line terminal installed outside a telecommunications carrier's office (on the user side).

Each of ONUs 41<1:N ₁ > to 44<1:N ₄ > controls the communication of information between users and PON 1. ONU 41<1:N ₁ > is connected to SPb 31 via different optical cables. ONU 42<1:N ₂ > is connected to SPb 32 via different optical cables. ONU 43<1:N ₃ > is connected to SPb 33 via different optical cables. ONU 44<1:N ₄ > is connected to SPb 34 via different optical cables.

Each of ONUs 45<1:N ₅ > to 48<1:N ₈ > controls communication of information between users and PON 2. ONU 45<1:N ₅ > is connected to SPb 35 via a different optical cable. ONU 46<1:N ₆ > is connected to SPb 36 via a different optical cable. ONU 47<1:N ₇ > is connected to SPb 37 via a different optical cable. ONU 48<1:N ₈ > is connected to SPb 38 via a different optical cable.

The switching device 50 is a device that switches the accommodation destination of the SPb 31-38 and the ONU 41<1:N ₁ >-48<1:N ₈ > between PON 1 and PON 2. The switching device 50 is provided between the SPa 21 and 22 and the SPb 31-38. As shown in FIG. 1, when the SPb 31-34 and the ONU 41<1:N ₁ >-44<1:N ₄ > are accommodated in the PON 1 and the SPb 35-38 and the ONU 45<1:N ₅ >-48<1:N ₈ > are accommodated in the PON 2, the switching device 50 connects the SPa 21 and the SPb 31-34, and also connects the SPa 22 and the SPb 35-38.

The switching device 50 is configured to be able to connect SPa21 to one of SPb35-38 and to connect SPa22 to SPb31 by switching between the connection between SPa21 and SPb31 and the connection between SPa22 and one of SPb35-38.The switching device 50 is configured to be able to connect SPa21 to one of SPb35-38 and to connect SPa22 to SPb32 by switching between the connection between SPa21 and SPb32 and the connection between SPa22 and one of SPb35-38. The switching device 50 is configured to be able to connect SPa21 to one of SPb35-38 and to connect SPa22 to SPb33 by switching between the connection between SPa21 and SPb33 and the connection between SPa22 and one of SPb35-38. The switching device 50 is configured to be able to connect SPa21 to one of SPb35-38 and to connect SPa22 to SPb33 by switching between the connection between SPa21 and SPb34 and the connection between SPa22 and one of SPb35-38.

Note that in the example shown in Figure 1, we have described a case where at least one ONU is connected to each of SPb31-38, but this is not limited to the case. For example, it is possible that no ONU is connected to each of SPb31-38. Below, this case will be described as the case where Nx = 0.

1.2 Switching Device Next, a configuration of a switching device included in an optical communication system according to an embodiment will be described with reference to Fig. 1 and Fig. 2. As shown in Fig. 1, a switching device 50 includes optical switches 51, 52, 53, 54, 55, 56, 57, and 58, and SPcs 61, 62, 63, 64, 65, 66, 67, and 68.

FIG. 2 is a block diagram showing an example of the configuration of a portion of an optical communication system according to an embodiment, including a switching device. In FIG. 2, OLTs 11 and 12, SPa 21 and 22, SPb 31 and 35, and a portion of switching device 50 that switches the connections between SPa 21 and 22 and SPb 31 and 35 are shown in optical communication system 1. Note that the configuration of the portion of switching device 50 that is not shown is equivalent to the portion of switching device 50 that switches the connections between SPa 21 and 22 and SPb 31 and 35.

Each of the optical switches 51 to 58 is a switch device configured to selectively output the received optical signal to a pre-specified port. Each of the optical switches 51 to 58 is installed within the telecommunications carrier's office together with the OLTs 11 and 12 and the SPas 21 and 22.

The optical switch 51 is connected to SPc 61, 65, 66, 67, and 68 via five different downstream optical cables. The optical switch 51 is connected to SPa 21 via one upstream optical cable. As a result, when SPc 61 is specified as the destination port, the optical switch 51 connects between SPa 21 and SPc 61. In this case, the optical switch 51 transfers the optical signal received from SPa 21 to SPc 61, but does not transfer it to SPc 65-68. Also, the optical switch 51 transfers the optical signal received from SPc 61 to SPa 21, but does not transfer the optical signal received from SPc 65-68 to SPa 21. On the other hand, when any of SPc 65-68 is specified as the destination port, the optical switch 51 connects between SPa 21 and the specified port of SPc 65-68. In this case, the optical switch 51 transfers the optical signal received from the SPa 21 to a specified port among the SPc 65-68, but does not transfer it to an unspecified port among the SPc 61 and the SPc 65-68. The optical switch 51 also transfers the optical signal received from a specified port among the SPc 65-68 to the SPa 21, but does not transfer the optical signal received from an unspecified port among the SPc 61 and the SPc 65-68 to the SPa 21.

The optical switch 52 is connected to SPc 62, 65, 66, 67, and 68 via five different downstream optical cables. The optical switch 52 is connected to SPa 21 via one upstream optical cable. As a result, when SPc 62 is specified as the destination port, the optical switch 52 connects between SPa 21 and SPc 62. In this case, the optical switch 52 transfers the optical signal received from SPa 21 to SPc 62, but does not transfer it to SPc 65-68. Also, the optical switch 52 transfers the optical signal received from SPc 62 to SPa 21, but does not transfer the optical signal received from SPc 65-68 to SPa 21. On the other hand, when any of SPc 65-68 is specified as the destination port, the optical switch 52 connects between SPa 21 and the specified port of SPc 65-68. In this case, the optical switch 52 transfers the optical signal received from the SPa 21 to a specified port among the SPc 65-68, but does not transfer it to the unspecified port among the SPc 62 and the SPc 65-68. Also, the optical switch 52 transfers the optical signal received from the specified port among the SPc 65-68 to the SPa 21, but does not transfer the optical signal received from the unspecified port among the SPc 62 and the SPc 65-68 to the SPa 21.

The optical switch 53 is connected to SPc 63, 65, 66, 67, and 68 via five different downstream optical cables. The optical switch 53 is connected to SPa 21 via one upstream optical cable. As a result, when SPc 63 is specified as the destination port, the optical switch 53 connects between SPa 21 and SPc 63. In this case, the optical switch 53 transfers the optical signal received from SPa 21 to SPc 63, but does not transfer it to SPc 65-68. Also, the optical switch 53 transfers the optical signal received from SPc 63 to SPa 21, but does not transfer the optical signal received from SPc 65-68 to SPa 21. On the other hand, when any of SPc 65-68 is specified as the destination port, the optical switch 53 connects between SPa 21 and the specified port of SPc 65-68. In this case, the optical switch 53 transfers the optical signal received from the SPa 21 to a specified port among the SPc 65 to 68, but does not transfer it to the unspecified port among the SPc 63 and the SPc 65 to 68. The optical switch 53 also transfers the optical signal received from a specified port among the SPc 65 to 68 to the SPa 21, but does not transfer the optical signal received from the unspecified port among the SPc 63 and the SPc 65 to 68 to the SPa 21.

The optical switch 54 is connected to SPc 64, 65, 66, 67, and 68 via five different downstream optical cables. The optical switch 54 is connected to SPa 21 via one upstream optical cable. As a result, when SPc 64 is specified as the destination port, the optical switch 54 connects between SPa 21 and SPc 64. In this case, the optical switch 54 transfers the optical signal received from SPa 21 to SPc 64, but does not transfer it to SPc 65-68. Also, the optical switch 54 transfers the optical signal received from SPc 64 to SPa 21, but does not transfer the optical signal received from SPc 65-68 to SPa 21. On the other hand, when any of SPc 65-68 is specified as the destination port, the optical switch 54 connects between SPa 21 and the specified port of SPc 65-68. In this case, the optical switch 54 transfers the optical signal received from the SPa 21 to a specified port among the SPc 65 to 68, but does not transfer it to the unspecified port among the SPc 64 and the SPc 65 to 68. The optical switch 54 also transfers the optical signal received from a specified port among the SPc 65 to 68 to the SPa 21, but does not transfer the optical signal received from the unspecified port among the SPc 64 and the SPc 65 to 68 to the SPa 21.

The optical switch 55 is connected to SPc 65, 61, 62, 63, and 64 via five different downstream optical cables. The optical switch 55 is connected to SPa 22 via one upstream optical cable. As a result, when SPc 65 is specified as the destination port, the optical switch 55 connects between SPa 22 and SPc 65. In this case, the optical switch 55 transfers the optical signal received from SPa 22 to SPc 65, but does not transfer it to SPc 61-64. Also, the optical switch 55 transfers the optical signal received from SPc 65 to SPa 22, but does not transfer the optical signal received from SPc 61-64 to SPa 22. On the other hand, when any of SPc 61-64 is specified as the destination port, the optical switch 55 connects between SPa 22 and the specified port of SPc 61-64. In this case, the optical switch 55 transfers the optical signal received from the SPa 22 to a specified port among the SPc 61 to 64, but does not transfer it to the unspecified port among the SPc 65 and the SPc 61 to 64. The optical switch 55 also transfers the optical signal received from a specified port among the SPc 61 to 64 to the SPa 22, but does not transfer the optical signal received from the unspecified port among the SPc 65 and the SPc 61 to 64 to the SPa 22.

The optical switch 56 is connected to SPc 66, 61, 62, 63, and 64 via five different downstream optical cables. The optical switch 56 is connected to SPa 22 via one upstream optical cable. As a result, when SPc 66 is specified as the destination port, the optical switch 56 connects between SPa 22 and SPc 66. In this case, the optical switch 56 transfers the optical signal received from SPa 22 to SPc 66, but does not transfer it to SPc 61-64. Also, the optical switch 56 transfers the optical signal received from SPc 66 to SPa 22, but does not transfer the optical signal received from SPc 61-64 to SPa 22. On the other hand, when any of SPc 61-64 is specified as the destination port, the optical switch 56 connects between SPa 22 and the specified port of SPc 61-64. In this case, the optical switch 56 transfers the optical signal received from the SPa 22 to a specified port among the SPc 61 to 64, but does not transfer it to an unspecified port among the SPc 66 and the SPc 61 to 64. The optical switch 56 also transfers the optical signal received from a specified port among the SPc 61 to 64 to the SPa 22, but does not transfer the optical signal received from an unspecified port among the SPc 66 and the SPc 61 to 64 to the SPa 22.

The optical switch 57 is connected to SPc 67, 61, 62, 63, and 64 via five different downstream optical cables. The optical switch 57 is connected to SPa 22 via one upstream optical cable. As a result, when SPc 67 is specified as the destination port, the optical switch 57 connects between SPa 22 and SPc 67. In this case, the optical switch 57 transfers the optical signal received from SPa 22 to SPc 67, but does not transfer it to SPc 61-64. Also, the optical switch 57 transfers the optical signal received from SPc 67 to SPa 22, but does not transfer the optical signal received from SPc 61-64 to SPa 22. On the other hand, when any of SPc 61-64 is specified as the destination port, the optical switch 57 connects between SPa 22 and the specified port of SPc 61-64. In this case, the optical switch 57 transfers the optical signal received from the SPa 22 to a specified port among the SPc 61 to 64, but does not transfer it to the unspecified port among the SPc 67 and the SPc 61 to 64. Also, the optical switch 57 transfers the optical signal received from a specified port among the SPc 61 to 64 to the SPa 22, but does not transfer the optical signal received from the unspecified port among the SPc 67 and the SPc 61 to 64 to the SPa 22.

The optical switch 58 is connected to SPc 68, 61, 62, 63, and 64 via five different downstream optical cables. The optical switch 58 is connected to SPa 22 via one upstream optical cable. As a result, when SPc 68 is specified as the destination port, the optical switch 58 connects between SPa 22 and SPc 68. In this case, the optical switch 58 transfers the optical signal received from SPa 22 to SPc 68, but does not transfer it to SPc 61-64. Also, the optical switch 58 transfers the optical signal received from SPc 68 to SPa 22, but does not transfer the optical signal received from SPc 61-64 to SPa 22. On the other hand, when any of SPc 61-64 is specified as the destination port, the optical switch 58 connects between SPa 22 and the specified port of SPc 61-64. In this case, the optical switch 58 transfers the optical signal received from the SPa 22 to a specified port among the SPc 61 to 64, but does not transfer it to the unspecified port among the SPc 68 and the SPc 61 to 64. The optical switch 58 also transfers the optical signal received from a specified port among the SPc 61 to 64 to the SPa 22, but does not transfer the optical signal received from the unspecified port among the SPc 68 and the SPc 61 to 64 to the SPa 22.

The operation of switching between the ONUs accommodated in PON1 and the ONUs accommodated in PON2 by the switching device 50 as described above (hereinafter referred to as the "switching operation") is preferably performed synchronously in order to prevent communication interruptions on the user side.

Each of the SPcs 61 to 68 is a passive element that does not require a power source. Each of the SPcs 61 to 68 is, for example, an optical splitter with up to five branches. The SPcs 61 to 68, together with the SPcs 31 to 38 and the ONUs 41<1:N ₁ > to 48<1:N ₈ >, are provided outside the telecommunications carrier's office (i.e., on the user side).

SPc 61 branches the optical signal received from SPb 31. The optical signals branched by SPc 61 are transmitted to optical switches 51 and 55-58 via five different optical cables. SPc 61 also combines the five types of optical signals transmitted from optical switches 51 and 55-58 via five different optical cables. The optical signals combined by SPc 61 are transmitted to SPb 31 via a single optical cable.

SPc 62 branches the optical signal received from SPb 32. The optical signals branched by SPc 62 are transmitted to optical switches 52 and 55-58 via five different optical cables. SPc 62 also combines the five types of optical signals transmitted from optical switches 52 and 55-58 via five different optical cables. The optical signals combined by SPc 62 are transmitted to SPb 32 via a single optical cable.

SPc 63 branches the optical signal received from SPb 33. The optical signals branched by SPc 63 are transmitted to optical switches 53 and 55-58 via five different optical cables. SPc 63 also combines the five types of optical signals transmitted from optical switches 53 and 55-58 via five different optical cables. The optical signals combined by SPc 63 are transmitted to SPb 33 via a single optical cable.

SPc 64 branches the optical signal received from SPb 34. The optical signals branched by SPc 64 are transmitted to optical switches 54 and 55-58 via five different optical cables. SPc 64 also combines the five types of optical signals transmitted from optical switches 54 and 55-58 via five different optical cables. The optical signals combined by SPc 64 are transmitted to SPb 34 via a single optical cable.

SPc 65 branches the optical signal received from SPb 35. The optical signals branched by SPc 65 are transmitted to optical switches 51-54 and 55 via five different optical cables. SPc 65 also combines the five types of optical signals transmitted from optical switches 51-54 and 55 via five different optical cables. The optical signals combined by SPc 65 are transmitted to SPb 35 via a single optical cable.

SPc 66 branches the optical signal received from SPb 36. The optical signals branched by SPc 66 are transmitted to optical switches 51-54 and 56 via five different optical cables. SPc 66 also combines the five types of optical signals transmitted from optical switches 51-54 and 56 via five different optical cables. The optical signals combined by SPc 66 are transmitted to SPb 36 via a single optical cable.

SPc 67 branches the optical signal received from SPb 37. The optical signals branched by SPc 67 are transmitted to optical switches 51-54 and 57 via five different optical cables. SPc 67 also combines the five types of optical signals transmitted from optical switches 51-54 and 57 via five different optical cables. The optical signals combined by SPc 67 are transmitted to SPb 37 via a single optical cable.

SPc 68 branches the optical signal received from SPb 38. The optical signals branched by SPc 68 are sent to optical switches 51-54 and 58 via five different optical cables. SPc 68 also combines the five types of optical signals sent from optical switches 51-54 and 58 via five different optical cables. The optical signals combined by SPc 68 are sent to SPb 35 via a single optical cable.

With the above configuration, each of SPc 61-68 realizes 5 inputs and 1 output for downstream optical signals, and 1 input and 5 outputs for upstream optical signals.

1.3 Communication Control Device Next, the configuration of a communication control device included in the optical communication system according to the embodiment will be described.

FIG. 3 is a block diagram showing an example of the hardware configuration of a communication control device according to an embodiment. As shown in FIG. 3, the communication control device 5 includes a control circuit 71, a higher-level communication module 72, a PON communication module 73, a user interface 74, a storage 75, a drive 76, and a storage medium 77.

The control circuit 71 is a circuit that provides overall control of each component of the communication control device 5. The control circuit 71 includes a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The ROM of the control circuit 71 stores programs and the like used in various processes in the communication control device 5. The CPU of the control circuit 71 controls the entire communication control device 5 in accordance with the programs stored in the ROM of the control circuit 71. The RAM of the control circuit 71 is used as a working area for the CPU of the control circuit 71.

The upper communication module 72 is a circuit used for data communication with the network NW (i.e., a layer higher than the PON). The PON communication module 73 is a circuit used for data communication with the PON.

The user interface 74 is an interface that handles communication between the telecommunications carrier and the control circuit 71. The user interface 74 includes input devices and output devices. The input devices include, for example, a keyboard, a touch panel, and operation buttons. The output devices include, for example, an LCD (liquid crystal display) or an EL (electroluminescence) display. The user interface 74 converts the input from the telecommunications carrier into an electrical signal, and then transmits it to the control circuit 71. The user interface 74 outputs the execution result based on the input from the telecommunications carrier to the telecommunications carrier.

Storage 75 includes, for example, a hard disk drive (HDD) or a solid state drive (SSD). Storage 75 stores information used in various processes in the communication control device 5.

The drive 76 is a device for reading software stored in the storage medium 77. The drive 76 includes, for example, a CD (compact disk) drive and a DVD (digital versatile disk) drive.

The storage medium 77 is a medium that stores software electrically, magnetically, optically, mechanically, or chemically. The storage medium 77 may store programs for executing various processes in the communication control device 5.

FIG. 4 is a block diagram showing an example of the functional configuration of a communication control device according to an embodiment. As shown in FIG. 4, the CPU of the control circuit 71 loads a program stored in the ROM or storage medium 77 of the control circuit 71 into the RAM of the control circuit 71. The CPU of the control circuit 71 then interprets and executes the program loaded into the RAM of the control circuit 71. As a result, the communication control device 5 functions as a computer including a switching request acquisition unit 81, a switching target selection unit 82, a switching instruction unit 83, a switching completion notification acquisition unit 84, and a control result output unit 85.

The switching request acquisition unit 81 acquires a switching request from a higher layer via the network NW. The switching request is a command requesting the execution of a switching operation. The switching request may be issued periodically, for example. Also, for example, the switching request may be issued in response to an inquiry to a telecommunications carrier by a user who is communicating using an ONU with an unstable communication situation. The switching request acquisition unit 81 transmits the acquired switching request to the switching target selection unit 82.

When the switching target selection unit 82 receives a switching request, it inquires about the communication usage status within the optical communication system 1, for example, via the network NW. The switching target selection unit 82 acquires the communication usage status DB 90 as the result of the inquiry.

FIG. 5 is a diagram showing an example of the data structure of a communication usage status DB used in the optical communication system according to the embodiment. As shown in FIG. 5, the communication usage status DB 90 stores the communication usage status for each OSW accommodated in each OLT. As a specific example of the communication usage status, FIG. 5 shows an example in which "emergency call usage status," "current usage bandwidth," and "past usage bandwidth" are stored.

"Emergency call usage" is information indicating whether or not there is an ONU using an emergency call among the ONUs communicating using the corresponding OSW. For example, when "emergency call usage" is "true," it indicates that there is an ONU using an emergency call among the ONUs communicating using the corresponding OSW. When "emergency call usage" is "false," it indicates that there is no ONU using an emergency call among the ONUs communicating using the corresponding OSW.

"Current bandwidth usage" is information that indicates the total bandwidth usage of ONUs communicating using the corresponding OSW in real time or in a specified period of the most recent time. "Past bandwidth usage" is information that indicates the total bandwidth usage of ONUs communicating using the corresponding OSW in a specified period of time that is older than the aggregation period for "current bandwidth usage."

In the example of FIG. 5, by referring to communication usage status DB 90, it can be seen that emergency calls are being used in OSWs 53, 54, 56, and 58, and that emergency calls are not being used in OSWs 51, 52, 55, and 57. It can also be seen that, compared to the past bandwidth usage, the current bandwidth usage has increased overall in OLT 11, while the current bandwidth usage has decreased in OLT 12.

The functional configuration of the communication control device 5 will be described again with reference to FIG. 4.

The switching target selection unit 82 determines whether or not to execute a switching operation based on the communication usage status DB 90. Specifically, for example, when making the determination, the switching target selection unit 82 determines at least one of the communication usage statuses stored in the communication usage status DB as a parameter. Then, the switching target selection unit 82 determines whether or not to execute a switching operation by comparing the determined parameter with a preset reference value (threshold value).

If it is determined that a switching operation is to be performed, the switching target selection unit 82 selects a pair of optical switches that are to be the target of the switching operation as the switching targets. The pair of optical switches that are to be the switching targets is, for example, a pair of one optical switch among OSWs 51-54 accommodated in PON1 and one optical switch among OSWs 55-58 accommodated in PON2. The switching target selection unit 82 then transmits the selected switching target to the switching instruction unit 83. On the other hand, if it is determined that a switching operation is not to be performed, the switching target selection unit 82 transmits a determination result indicating that a switching operation is not to be performed to the control result output unit 85.

When the switching instruction unit 83 receives the selected switching target, it instructs the switching target (i.e., one optical switch among OSWs 51-54 accommodated in PON1 and one optical switch among OSWs 55-58 accommodated in PON2) to change the designated port. The instruction is sent to the switching device 50, for example, via OLTs 11 and 12.

The switching completion notification acquisition unit 84 acquires a completion notification of the execution result of the switching operation executed based on the instruction by the switching instruction unit 83 from the PON. The completion notification includes, for example, information indicating the connection status before switching and the connection status after switching. The switching completion notification acquisition unit 84 transmits the acquired completion notification to the control result output unit 85.

When the control result output unit 85 receives a completion notification of the switching operation from the switching completion notification acquisition unit 84, it outputs the completion notification as a control result to the upper layer via the network NW. When the control result output unit 85 receives a determination result from the switching target selection unit 82 that the switching operation will not be executed, it outputs the determination result as a control result to the upper layer via the network NW.

1.2 Operation Next, the operation of the optical communication system according to the embodiment will be described.

1.2.1 A Series of Processes Including a Switching Operation FIG. 6 is a flowchart showing an example of a series of processes including a switching operation in the optical communication system according to the embodiment.

When the series of processes starts (START), the communication control device 5 waits until the switching request acquisition unit 81 acquires a switching request from the upper layer (ST11).

When a switching request is received, the switching target selection unit 82 acquires the communication usage status DB 90 (ST12).

The switching target selection unit 82 executes a switching target selection process based on the communication usage status DB 90 acquired in the process of ST12 (ST13). The details of the switching target selection process will be described later.

The switching target selection unit 82 determines whether a switching target has been selected by the switching target selection process of ST13 (ST14).

If a switching target is selected (ST14; yes), the switching instruction unit 83 instructs the switching device 50 to switch the OSW connection based on the selection result by the switching target selection process in ST13. Then, the switching device 50 executes switching of the OSW connection based on the contents of the instruction from the switching instruction unit 83 (ST15).

The switching completion notification acquisition unit 84 acquires a switching operation completion notification from the switching device 50 as a result of the execution of the process of ST15 (ST16).

After processing in ST16, the control result output unit 85 outputs the completion notification of the switching operation acquired in processing in ST16 as the control result to the upper layer (ST17). If a switching target was not selected (ST14; yes), the control result output unit 85 outputs information indicating that a switching target was not selected in the switching target selection processing in ST13 to the upper layer (ST17).

When the processing of ST17 is completed, the series of processes including the switching operation is completed (END).

1.2.2 Switching Target Selection Process Fig. 7 is a flowchart showing an example of a switching target selection process in the optical communication system according to the embodiment. The processes in ST21 to ST26 shown in Fig. 7 correspond to the process in ST13 in Fig. 6.

When the switching target selection process starts (START), the switching target selection unit 82 refers to the communication usage status DB 90 and determines whether the difference in the current bandwidth usage between the PONs is equal to or greater than a threshold (ST21). The threshold can be determined based on, for example, the change in the difference in the past bandwidth usage between the PONs.

If the difference in the current bandwidth usage between PONs is equal to or greater than the threshold (ST21; yes), the switching target selection unit 82 extracts the OSW with the largest bandwidth usage (hereinafter referred to as "OSW-A" for convenience) from among the multiple OSWs in the PON with large bandwidth usage and that are not used for emergency calls (ST22).

The switching target selection unit 82 extracts the OSW with the smallest bandwidth usage (hereinafter, for convenience, referred to as "OSW-B") from among the multiple OSWs in the PON with small bandwidth usage and that are not used for emergency calls (ST23).

The switching target selection unit 82 determines whether the bandwidth used by OSW-A extracted in the process of ST22 is greater than the bandwidth used by OSW-B extracted in the process of ST23 (ST24).

If the bandwidth used by OSW-A is greater than the bandwidth used by OSW-B (ST24; yes), the switching target selection unit 82 selects the pair of OSW-A extracted in the process of ST22 and OSW-B extracted in the process of ST23 as switching targets (ST25).

If the difference in the current bandwidth usage between the PONs is less than the threshold (ST21; no), or if the bandwidth usage of OSW-A is equal to or less than the bandwidth usage of OSW-B (ST24; no), the switching target selection unit 82 determines that switching is not necessary (ST26).

When the processing of ST26 is completed, the switching target selection process ends (END).

1.3 Effects of the embodiment According to the embodiment, the communication control device 5 includes a switching request acquisition unit 81, a switching target selection unit 82, and a switching instruction unit 83. The switching request acquisition unit 81 acquires the usage status of the communication by the ONUs 41<1:N ₁ > to 48<1:N ₈ > via the SPas 21 and 22 as a communication usage status DB 90. The switching target selection unit 82 selects a switching target from the ONUs 41<1:N ₁ > to 48<1:N ₈ > based on the acquired communication usage status DB 90. The switching instruction unit 83 instructs the switching device 50 to execute a switching operation for the selected switching target. This makes it possible to determine whether or not the switching operation by the switching device 50 can be executed by automatic control according to an instruction from the communication control device 5, not manually. Therefore, compared to the manual case, it is possible to shorten the time required for collecting information for determining whether or not the switching operation can be executed and for making the determination. In other words, in a situation where the communication usage status is constantly changing, it is possible to avoid a situation where the information used when determining to execute a switching operation is already outdated at the time of executing the switching operation. Therefore, it is possible to accurately equalize the bandwidths allocated to ONUs between different PONs.

The communication usage status DB 90 also includes the bandwidths used in PON1 and PON2 by the ONUs 41<1:N ₁ > to 48<1:N ₈ >. The switching target selection unit 82 determines whether or not a switching operation needs to be performed based on whether or not the difference between the larger and smaller bandwidths used in each PON is equal to or greater than a threshold. This allows a part of the bandwidth used in a PON with a relatively large bandwidth to be switched to a PON with a relatively small bandwidth, thereby facilitating the equalization of the bandwidths used between the PONs.

The communication usage status DB 90 also includes information indicating whether emergency calls are being used in each OSW. The switching target selection unit 82 selects a switching target from among OSWs that are not using emergency calls and ONUs that are communicating through the OSWs. This makes it possible to prevent emergency communications from being cut off due to communication failures such as momentary interruptions that may occur during switching operations.

The switching device 50 further includes an SPc 65 that branches an optical signal from the SPb 35. The SPc 65 is connected to the optical switches 51 and 55 by different optical cables. The communication control device 5 executes a switching operation from the PON2 that accommodates the ONU 45<1:N ₅ > to the PON1 in synchronization with a switching operation from the PON1 that accommodates the ONU 41<1:N ₁ > to the PON2. This makes it possible to prevent the connection of the ONU 45<1:N ₅ > from being disconnected by the switching operation of the ONU 41<1:N ₁ > when the ONU 45<1:N ₅ > exists.

Furthermore, the optical switches 51 and 55 of the switching device 50 are provided within the telecommunications carrier's office. This makes it easy to secure power for the optical switches 51 and 55. Even if the switching operation is performed manually, the switching work can be easily performed.

The signal loss of the optical switches 51 and 55 is, for example, about 0.5 dB. The signal loss caused by the SPcs 61 and 65 does not affect downstream signals, as they are simply multiplexed. For upstream signals, the loss can be suppressed to about 3 dB by using a two-branch optical splitter. Therefore, the switching device 50 can perform switching operations with almost no effect on the service quality of optical communications.

2. Modifications, etc. In the above embodiment, the switching device 50 is provided between the SPa 21 and 22 and the SPb 31 to 38, but the present invention is not limited to this. For example, the switching device 50 may be provided between the SPb 31 to 38 and the ONUs 41<1:N ₁ > to 48<1:N ₈ >. In this case, the switching device 50 can switch the bandwidth used between the PONs on an ONU-by-ONU basis. This allows fine adjustment of the bandwidth used with higher accuracy.

In the above embodiment, a case where a switching operation is performed between PON1 and PON2 has been described, but this is not limited to the above. For example, a switching operation may be performed between three or more PONs. In this case, the switching device 50 is provided so as to span three or more PONs. Furthermore, the communication control device 5 is configured so as to be able to transmit a switching instruction to three or more PONs.

In the above embodiment, a case has been described in which the program for executing the switching operation is executed by the communication control device 5 in the optical communication system 1, but this is not limited to the above. For example, the program for executing the switching operation may be executed by a computing resource on the cloud.

The present invention is not limited to the above-described embodiments, and can be modified in various ways during implementation without departing from the gist of the invention. The embodiments may also be implemented in appropriate combination, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combinations selected from the multiple constituent elements disclosed. For example, if the problem can be solved and an effect can be obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiments, the configuration from which these constituent elements are deleted can be extracted as an invention.

1... Optical communication system 5... Communication control device 11, 12... OLT
21, 22...SPa
31, 32, 33, 34, 35, 36, 37, 38...SPb
41, 42, 43, 44, 45, 46, 47, 48...ONU
50...switching device 51, 52, 53, 54, 55, 56, 57, 58...optical switch 61, 62, 63, 64, 65, 66, 67, 68...SPc
71: Control circuit 72: Upper communication module 73: PON communication module 74: User interface 75: Storage 76: Drive 77: Storage medium 81: Switching request acquisition unit 82: Switching target selection unit 83: Switching instruction unit 84: Switching completion notification acquisition unit 85: Control result output unit 90: Communication usage status DB

Claims (8)

A communication control device for controlling communication in an optical communication system,
The optical communication system includes:
A first termination device;
A second termination device;
a first splitter for splitting an optical signal from the first terminal device;
a second splitter for splitting an optical signal from the second terminal device;
a plurality of third termination devices;
a switching device provided between the first splitter and the second splitter and the plurality of third terminal devices, configured to perform a switching operation to switch communication between at least one of the plurality of third terminal devices and the first terminal device via the first splitter to communication between the at least one of the plurality of third terminal devices and the second terminal device via the second splitter;
The communication control device;
Equipped with
The communication control device includes:
an acquisition unit that acquires a usage status of communication via the first splitter and the second splitter by the third terminal devices;
a selection unit that selects a switching target from the plurality of third termination devices based on the acquired usage status;
an instruction unit that instructs the switching device to execute the switching operation on the selected switching target;
A communication control device comprising: the usage status includes a first usage band of the communication by the plurality of third terminal devices via the first terminal device and a second usage band of the communication by the plurality of third terminal devices via the second terminal device;
The selection unit is configured to select the switching target from among the plurality of third termination devices when the first utilization band is equal to or greater than a threshold value with respect to the second utilization band.
The communication control device according to claim 1. The usage status further includes information indicating whether or not each of the plurality of third terminal devices uses an emergency call;
The selection unit is configured to select the switching target from a third terminating device that does not use an emergency call among the plurality of third terminating devices.
3. The communication control device according to claim 2. The switching device is
a first optical switch connected to the first splitter;
a second optical switch connected to the second splitter;
a third splitter connected to the first optical switch and the second optical switch by different optical cables, the third splitter splitting an optical signal from the at least one third terminal device;
Including,
The communication control device according to claim 1. The instruction unit is
instructing the first optical switch to stop communication between the first terminal device and the first splitter that is the switching target, via the first terminal device and the first splitter;
and instructing the second optical switch to start communication between the second terminal device and the second terminal device via the second splitter that is the switching target, via the second terminal device and the second splitter.
5. The communication control device according to claim 4. The first terminal device and the second terminal device are optical line terminals (OLTs),
The third terminal device is an ONU (optical network unit).
The communication control device according to claim 1. a switching device provided between the first and second splitters and the third terminal devices, the switching device being configured to perform a switching operation of switching a connection between at least one third terminal device among the third terminal devices and the first terminal device via the first splitter to a connection between the at least one third terminal device among the third terminal devices and the second terminal device via the second splitter; and a communication control device, the switching device comprising: a first terminal device; a second terminal device;
acquiring a usage status of communication via the first splitter and the second splitter by the third terminal devices;
selecting a switching target from the plurality of third terminal devices based on the acquired usage status;
instructing the switching device to execute the switching operation on the selected switching target;
A communication control method comprising: an optical communication system including a first terminal device, a second terminal device, a first splitter that branches an optical signal from the first terminal device, a second splitter that branches an optical signal from the second terminal device, a plurality of third terminal devices, a switching device provided between the first splitter and the second splitter and the plurality of third terminal devices, and configured to perform a switching operation of switching a connection between at least one third terminal device among the plurality of third terminal devices and the first terminal device via the first splitter to a connection between the third terminal device and the first terminal device via the second splitter, and a communication control device;
The communication control device includes:
acquiring a usage status of communication via the first splitter and the second splitter by the third terminal devices;
selecting a switching target from the plurality of third terminal devices based on the acquired usage status;
instructing the switching device to execute the switching operation on the selected switching target;
A program for executing.

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