Communication device, management device, and communication method

Abstract

A communication device communicates with another communication device via an all-photonics network (APN). The communication device includes circuitry that obtains characteristic information for each of a plurality of paths in the APN between the communication device and the another communication device. The circuitry also selects one path of the plurality of paths based on the characteristic information and based on data to be transmitted to the another communication device. Then the circuitry transmits the data via the one path selected.

Description

COMMUNICATION DEVICE, MANAGEMENT DEVICE, AND COMMUNICATION METHOD

[0001] The present disclosure relates to a communication device, a management device, and a communication method.

[0002] As a type of optical network, an all-photonics network (APN) in which all communication networks are based on photonics is known. In the APN, an optical signal is transmitted, and basically no photoelectric conversion is performed. That is, in the APN, an optical signal is transmitted without being converted into an electrical signal. Therefore, in the APN, in general, a processing propagation delay is short, and a delay variation is also small.

[0003] WO 2022 / 44137 AJP 2012-532494 T

[0004] In the future, when the APN becomes widespread, it is considered that the APN is constructed to cover a wide area, for example, all over Japan. When the APN is constructed, for example, it is conceivable that the APN is constructed in a mesh configuration so that a plurality of communication paths can be used in order to ensure availability of communication even if an accident or a failure occurs.

[0005] In a network with a mesh configuration, there are a plurality of paths from one node to another node. A dynamic characteristic such as a delay time varies between the plurality of paths. Even in the APN, the delay time is short, and the delay variation is small, but the delay time and the delay variation are not completely zero.

[0006] It is required to provide applications and services that perform data communication utilizing such characteristics of an optical network (for example, the APN).

[0007] Therefore, the present disclosure provides a communication device, a management device, and a communication method capable of implementing data communication utilizing characteristics of an optical network.

[0008] It should be noted that the above-mentioned problem or purpose is only one of a plurality of problems or purposes that can be solved or achieved by a plurality of embodiments disclosed in the present specification.

[0009] A communication device of the present disclosure communicates with another communication device via an optical network. The communication device includes a control unit. The control unit requests a management device disposed at a node of the optical network and managing a dynamic characteristic of a transmission path of the optical network to transmit dynamic characteristic information regarding the dynamic characteristic of a communication path with the another communication device by using an application programming interface (API). The control unit acquires the dynamic characteristic information from the management device.

[0010] A communication device of the present disclosure is also configured to communicate with another communication device via an all-photonics network (APN). The communication device includes circuitry configured to obtain characteristic information for each of a plurality of paths in the APN between the communication device and the another communication device, select one path of the plurality of paths based on the characteristic information and based on data to be transmitted to the another communication device, and transmit the data via the one path selected.

[0011] A management device according to the present disclosure manages communication in an all-photonics network (APN). The management device includes circuitry configured to measure at least one characteristic of each of a plurality of paths in the APN to obtain characteristic information of the plurality of paths, store the characteristic information, in response to a request from a communication device, provide the characteristic information to the communication device, and update the characteristic information at least one of periodically or upon a change in the APN.

[0012] A method according to the present disclosure for a communication device configured to communicate with another communication device via an all-photonics network (APN)includes obtaining characteristic information for each of a plurality of paths in the APN between the communication device and the another communication device, selecting one path of the plurality of paths based on the characteristic information and based on data to be transmitted to the another communication device, and transmitting the data via the one path selected.

[0013] Fig. 1 is a diagram illustrating an example of an overall configuration of a communication system according to an embodiment of the present disclosure.Fig. 2 is a diagram illustrating an example of an all-photonics network (APN) 40 according to an embodiment of the present disclosure.Fig. 3 is a block diagram illustrating an example of a configuration of a management device according to an embodiment of the present disclosure.Fig. 4 is a table illustrating an example of characteristic information according to the present embodiment.Fig. 5 is a diagram for describing an example of a dispersion according to an embodiment of the present disclosure.Fig. 6 is a diagram illustrating an example of signal transmission according to an embodiment of the present disclosure.Fig. 7 is a diagram illustrating an example of buffering by a reception side according to an embodiment of the present disclosure.Fig. 8 is a diagram illustrating another example of the signal transmission according to an embodiment of the present disclosure.Fig. 9 is a diagram illustrating an example of buffering by the reception side according to an embodiment of the present disclosure.Fig. 10 is a table illustrating another example of the characteristic information according to the present embodiment.Fig. 11 is a block diagram illustrating an example of a configuration of a communication device according to an embodiment of the present disclosure.Fig. 12 is a diagram for describing an example of an application programming interface (API) according to an embodiment of the present disclosure.Fig. 13 is a diagram for describing another example of the API according to an embodiment of the present disclosure.Fig. 14 is a diagram for describing another example of the API according to an embodiment of the present disclosure.Fig. 15 is a diagram for describing another example of the API according to an embodiment of the present disclosure.Fig. 16 is a diagram for describing another example of the API according to an embodiment of the present disclosure.Fig. 17 is a diagram for describing another example of the API according to an embodiment of the present disclosure.Fig. 18 is a diagram for describing an example of communication processing according to an embodiment of the present disclosure.Fig. 19 is a flowchart illustrating an example of a flow of automatic path selection processing according to an embodiment of the present disclosure.Fig. 20 is a flowchart illustrating an example of a flow of path setting processing according to an embodiment of the present disclosure.Fig. 21 is a flowchart illustrating an example of a flow of event processing according to an embodiment of the present disclosure.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the appended drawings. Note that, in the present specification and the drawings, components having substantially the same functional configuration are provided with the same reference signs, so that an overlapping description of these components is omitted.

[0015] In addition, in the present specification and drawings, similar components of embodiments may be distinguished by adding at least one of different alphabets or different numerals after the same reference sign. However, in a case where it is not necessary to particularly distinguish each of similar components, only the same reference sign is assigned. For example, a plurality of components having substantially the same functional configuration are distinguished as necessary, such as a first communication device 30_1 and a second communication device 30_2. For example, in a case where it is not necessary to particularly distinguish the first communication device 30_1 and the second communication device 30_2, they are simply referred to as a communication device 30.

[0016] Each of one or more embodiments (including examples, modified examples, and application examples) described below can be implemented independently. On the other hand, at least some of the plurality of embodiments described below may be implemented in combination with at least some of other embodiments as appropriate. These plurality of embodiments may include novel characteristics different from each other. Therefore, these plurality of embodiments can contribute to achieve or solving different purposes or problems, and can exert different effects.

[0017] <<1. Introduction>> An all-photonics network (APN) has been developed as a next-generation optical network. In the APN, basically only an optical signal is transmitted between nodes. Therefore, in the APN, an optical signal is processed without being converted into an electrical signal. That is, in the APN, buffering or information processing by an electronic circuit is basically not performed after an optical signal is converted into an electrical signal.

[0018] Therefore, in general, the APN has characteristics that a processing propagation delay is short and a delay variation is small.

[0019] As described above, when the APN is constructed in such a way as to cover a wide area, it is considered the APN is constructed in a mesh configuration in order to ensure availability of communication even if an accident or a failure occurs.

[0020] In such an APN with a mesh configuration, there are a plurality of paths between two nodes. A transmission delay time in the plurality of paths is basically determined by a length of the path between the two nodes. More specifically, the transmission delay time is determined by a time during which a laser beam propagates in an optical fiber between the two nodes.

[0021] Generally, in the all-photonics network, a propagation delay time is short and the delay variation (jitter) is small, but the propagation delay time and the delay variation are not completely zero. The propagation delay time and a jitter amount are different for each of the plurality of paths.

[0022] The APN has a shorter transmission delay and a smaller delay variation compared with a best effort network (for example, the Internet) according to the related art. However, in the APN constructed in a mesh configuration, the propagation delay varies depending on a path selected at each time among the plurality of paths.

[0023] As described above, even in the APN having a short propagation delay and a small delay variation, a characteristic of the path (transmission path) is practically different for each selected path. Therefore, it is difficult to perform transmission on the premise of an ideal transmission path having zero delay and / or delay variation.

[0024] From the viewpoint of an application that provides a service to a user by using the APN, the APN has performance advantages of lower delay and lower jitter compared to the best effort network according to the related art.

[0025] On the other hand, even in the APN, the delay or jitter is not zero in reality, and the delay and jitter are not fixed values. Therefore, it is difficult for the application to provide a service on the premise that the delay or jitter is zero.

[0026] In a case where a network architecture of the APN is constructed on the premise that the delay or jitter is not zero, there is a possibility that the architecture is similar to that of the best effort network according to the related art. That is, processing similar to that of the best effort network according to the related art, such as absorption of the delay variation or smoothing of a rate variation, can be performed by buffering a signal in transmission and reception in the APN.

[0027] As described above, in a network architecture similar to the best effort network according to the related art, there is a possibility that an application fully utilizing the characteristics of the APN cannot be implemented. That is, in a case where a characteristic of a communication path (transmission path) of the APN is not determined, the APN can offer only a higher speed, lower delay, and lower jitter compared to the best effort network according to the related art.

[0028] In this way, it cannot be said that the application can provide the user with a service that fully utilizes the characteristics of the APN that is not the best effort type.

[0029] In addition, in a case where there are a plurality of transmission paths between a transmission side and a reception side, the propagation delay time is different for each path. In addition, a difference in equipment and a geographical environment of the transmission path are different. Examples of the geographical environment include physical distance, temperature, altitude / atmospheric pressure, vibration, and the like. Due to such a difference, the jitter amount may be different for each path. In addition, there is a possibility that power consumption is also different for each path due to the difference in equipment.

[0030] In such a situation, when the transmission side transmits data without considering the propagation delay, disconnection of data (for example, a video) due to a buffer failure on the reception side occurs depending on the selected path.

[0031] As a solution to the problem, it is general to provide a large reception buffer on the reception side. An accumulation amount in the reception buffer absorbs a variation in data rate and the delay variation depending on the transmission path. However, insertion of the reception buffer has a problem that the delay increases.

[0032] A communication device according to the present embodiment is a communication device that communicates with another communication device via an optical network (for example, the APN). The communication device includes a control unit. The control unit requests a management device to transmit dynamic characteristic information regarding a dynamic characteristic of a communication path with another communication device by using an application programming interface (API). The management device is disposed in a node of the optical network and manages the dynamic characteristic of the transmission path of the optical network. The control unit acquires the dynamic characteristic information from the management device.

[0033] As described above, in the optical network (for example, the APN) according to the present embodiment, the API by which an application or a service (more specifically, a communication device that executes an application or provides a service) can grasp characteristics (for example, the dynamic characteristic) of the optical network is defined.

[0034] The communication device can know a status (for example, the dynamic characteristic) of the optical network by using the API. As a result, the communication device can implement execution of an application and provision of a service on the premise of a network with low delay and / or low jitter. Examples of the dynamic characteristic include the delay and the jitter.

[0035] In the APN, the delay or jitter is almost determined by a static characteristic of the communication path. Furthermore, a variation range of the delay or jitter is basically small. Therefore, the management device can estimate the dynamic characteristic (for example, the delay amount or jitter amount) of the APN with higher accuracy.

[0036] By utilizing the characteristic, the communication device that executes an application (hereinafter, simply referred to as an application) can autonomously select an optimal path according to, for example, a characteristic of data to be transmitted and received.

[0037] It is considered that the application knows the characteristic of the data to be transmitted and received best. By selecting the optimal path, the application can utilize the characteristics of the APN and provide the user with a service according to the characteristic of the data to be transmitted and received.

[0038] To implement such a configuration, a transmission framework of the APN according to the present embodiment provides an API for an application in a higher layer. The application can acquire information regarding the characteristics of the APN (for example, the dynamic characteristic information) through the API, and can determine an optimal transmission method according to a service to be provided (for example, use of the data to be transmitted and received).

[0039] In a case where a delay time or a variation range of a data packet is known in advance, for example, the delay time is approximately constant and a variation range thereof is small, a communication system including the APN can reduce a margin of a transmission and / or reception buffer size for absorbing the delay variation or rate variation. The communication system can further shorten the delay time caused by temporarily storing a signal in the buffer.

[0040] In addition, in a case where the jitter amount is known in advance, for example, the jitter amount of the data packet that has passed through the APN is equal to or less than a predetermined value, the communication system can ensure phase locked loop (PLL) accuracy through the network.

[0041] Hitherto, a clock synchronization system can perform synchronization with desired accuracy in a local environment of a short distance, but it is difficult to perform synchronization with high accuracy across the entire network.

[0042] As described above, the communication system according to the present embodiment can provide the jitter amount of the APN. With such a configuration, the clock synchronization system can perform synchronization with desired accuracy across the APN.

[0043] Therefore, for example, the application can display a video at a remote location by using a synchronization signal generated from a high-precision clock on the transmission side, and can display the video without a synchronization issue at the remote location.

[0044] On the other hand, some data to be transmitted and received may be less required to be transmitted in real time with low delay and low jitter. When transmitting such data with low real-time property, the application selects a communication path with a lower network use cost rather than a communication path with low delay and low jitter. By doing so, the application can transfer the data at lower cost.

[0045] For example, there is a case where there is a restriction on power that can be used for data transmission, such as a case where data transmission is performed using eco-friendly power such as wind power generation or solar power, or a case where charging of a battery is not sufficient. In this case, it is also conceivable that the application preferentially selects a communication path with low power consumption to transmit the data.

[0046] In the present embodiment, the application defines an API capable of acquiring information regarding the dynamic characteristic of the APN, such as the delay time, the jitter amount, the communication cost, or the power consumption, and thus, the application can select a communication path according to data to be transmitted. As a result, the application can perform data communication utilizing the characteristics of the APN.

[0047] The dynamic characteristic information regarding the dynamic characteristic may include information regarding a communication path according to a desired dynamic characteristic. For example, the application notifies the management device of a desired dynamic characteristic (for example, a desired delay amount) via the API. The management device notifies the application of information regarding a communication path according to the dynamic characteristic of the APN.

[0048] The application selects a communication path to be used for data transmission from among communication paths notified from the management device. In this manner, the application may designate a condition of the dynamic characteristic, and the management device may notify the application of a communication path according to the condition. Also in this case, the application can perform data communication utilizing the characteristics of the APN.

[0049] As described above, the communication system according to the present embodiment defines the API in such a way that the communication device 30 can perform path selection according to a use case. As a result, the communication device 30 can know detailed information of the network, and can perform path selection according to the detailed information of the network.

[0050] In the best effort network according to the related art, the detailed dynamic characteristic cannot be managed (controlled). Alternatively, precise path selection based on a detailed operation characteristic has been difficult to perform. This is because a variation range of the dynamic characteristic of the best effort network according to the related art is very large. As described above, even in a case where path selection is precisely performed in the best effort network according to the related art or based on the detailed dynamic characteristic, there is a high possibility that the dynamic characteristic of the selected path varies and the desired path characteristic is not satisfied.

[0051] Therefore, in the best effort network according to the related art, it is less necessary to perform precise path selection until acquiring the detailed dynamic characteristic. This is also why it is called "best effort", and in the network according to the related art, there was a low need for an API for acquiring information regarding the detailed dynamic characteristic. On the other hand, in the APN, the detailed dynamic characteristic can be managed, and thus, the application is required to select a path according to a difference in path characteristic.

[0052] Therefore, in the communication system according to the present embodiment, path selection performed in a lower layer of a network hierarchical model can be performed by the application in the higher layer by using the API. Accordingly, it is possible to select a communication path satisfying the dynamic characteristic desired by the application.

[0053] In the APN, the delay and jitter are sufficiently small, and it is a problem to further reduce the delay and jitter. Therefore, in the present embodiment, attention is paid to a problem of selecting an optimal path from a plurality of paths that remains even when the network has low delay and low jitter. The technology according to the present embodiment enables an application that knows most the purpose of use of the network and the characteristic of transmission / reception data to perform the selection.

[0054] In the present embodiment, a use case in which the application provides the user with a service such as a large-scale real-time video of music live show, sports, or the like, and audio distribution is assumed. However, the service provided by the application is not limited to the distribution or the like. The technology of the present embodiment can be applied to applications that provide various services, but is particularly useful for transmission of a video and audio data.

[0055] <<2. Example of Configuration of Communication System>> <2-1. Example of Overall Configuration of Communication System> Fig. 1 is a diagram illustrating an example of an overall configuration of the communication system according to the embodiment of the present disclosure. The communication system illustrated in Fig. 1 includes a first management device 10_1, a second management device 10_2, the first communication device 30_1, the second communication device 30_2, and an APN 40.

[0056] The management device 10 is a device that manages characteristics of the APN 40. For example, the management device 10 is disposed at each node of the APN 40 as described below.

[0057] The management device 10 measures and / or estimates, for example, a dynamic characteristic of the APN 40 and holds the result in a characteristic information database. In addition, the management device 10 acquires information (for example, the dynamic characteristic) from, for example, the characteristic information database.

[0058] The characteristic information database holds a static characteristic of the APN 40, for example, in addition to the dynamic characteristic described above. The static characteristic includes information regarding a characteristic that does not change dynamically, such as a start point and an end point of the communication path and a physical distance of the communication path.

[0059] The static characteristic may be stored in the characteristic information database according to a notification from the management device 10, or may be stored by an administrator or the like of the APN 40. Alternatively, the static characteristic may be stored in the characteristic information database at the time of constructing or updating the APN 40.

[0060] The characteristic information database stores, for example, the static characteristic and the dynamic characteristic in association with each other.

[0061] The management device 10 generates the dynamic characteristic information regarding the dynamic characteristic according to a request from the communication device 30, and notifies the communication device 30 of the dynamic characteristic information. The dynamic characteristic includes, for example, information regarding a characteristic that dynamically changes in the communication path of the APN 40. The dynamic characteristic includes, for example, information regarding the delay time (delay amount) and the jitter amount of the communication path. Details of the dynamic characteristic are described below.

[0062] The dynamic characteristic information may be information including the dynamic characteristic itself or information generated according to the dynamic characteristic (for example, path information regarding the communication path). Details of the dynamic characteristic information are described below.

[0063] The first communication device 30_1 and the second communication device 30_2 are communication devices that mutually transmit and / or receive data. The communication device 30 is connected to the APN 40 via, for example, the management device 10. The communication device 30 performs data communication via the APN 40. That is, the communication device 30 performs communication using an optical signal.

[0064] Hereinafter, the communication device 30 that transmits data may be distinguished as a transmission device 30T, and the communication device 30 that receives data may be distinguished as a reception device 30R.

[0065] In Fig. 1, the communication system includes two management devices 10 (the first management device 10_1 and the second management device 10_2) and two communication devices 30 (the first communication device 30_1 and the second communication device 30_2), but the number of management devices 10 and the number of communication devices 30 are not limited to two. The communication system may include three or more management devices 10 and three or more communication devices 30.

[0066] Furthermore, a plurality of communication devices 30 may be connected to one management device 10. That is, the number of management devices 10 and the number of communication devices 30 may be different.

[0067] Optical communication may be performed between the management device 10 and the communication device 30, or communication other than optical communication may be performed between the management device 10 and the communication device 30.

[0068] Details of the APN 40 are described below.

[0069] The APN 40 is a network that transmits not an electrical signal but an optical signal as described above. In the APN 40, conversion of an optical signal to an electrical signal, buffering by an electronic circuit, and information processing are not performed. Therefore, in the APN 40, the delay time is generally short and the delay variation is small. The APN 40 is not the best effort network represented by the Internet or the like according to the related art, and is, for example, a network that can ensure an actual communication speed to some extent.

[0070] The APN 40 can provide a plurality of communication paths as communication paths between the first communication device 30_1 and the second communication device 30_2. The APN 40 is, for example, an optical network with a mesh configuration.

[0071] Fig. 2 is a diagram illustrating an example of the APN 40 according to the embodiment of the present disclosure. The APN 40 illustrated in Fig. 2 includes nodes A to J. For example, the management device 10 described above can be disposed at the node.

[0072] Each of the nodes A to J is connected to at least one other node via a transmission path. In the example of Fig. 2, the node A is connected to the nodes B and C. For example, the node D is connected to the node C. For example, the node F is connected to the nodes B, C, E, G, I, and J.

[0073] The nodes A to J of the APN 40 are connected to each other by at least one path. The APN 40 is a mesh network. As the APN 40 is implemented by a mesh network, it is possible to secure path redundancy, secure a land where a communication line can be laid, stably supply power, cope with an increase in traffic, and the like.

[0074] In the APN 40 according to the present embodiment, there is a path having a larger jitter amount than other paths. In the example of Fig. 2, the jitter increases in a path between the nodes A and C (hereinafter, also referred to as a path AC), a path between the nodes E and J (hereinafter, also referred to as a path EJ), and a path between the nodes F and J (hereinafter, also referred to as a path FJ) as compared with other paths.

[0075] In addition, in the APN 40 according to the present embodiment, there is a path having a larger delay variation than other paths. In the example of Fig. 2, the delay variation increases in a path between the nodes B and F (hereinafter, also referred to as a path BF), a path between the nodes F and G (hereinafter, also referred to as a path FG), and a path between the nodes I and J (hereinafter, also referred to as a path IJ) as compared with other paths.

[0076] The number of nodes, connections, and paths in which the jitter and the delay variation increase are examples. For example, the number of nodes included in the APN 40 according to the present embodiment may be nine or less or 11 or more.

[0077] <2-2. Example of Configuration of Management Device> The management device 10 is, for example, a device disposed at the node of the APN 40. The management device 10 may be, for example, a device that relays connection between the communication device 30 and the APN 40.

[0078] Fig. 3 is a block diagram illustrating an example of a configuration of the management device 10 according to the embodiment of the present disclosure. The management device 10 includes a communication unit 110, a storage unit 120, and a control unit 130.

[0079] Note that the configuration illustrated in Fig. 3 is a functional configuration, and a hardware configuration may be different from this. Furthermore, the functions of the management device 10 may be statically or dynamically distributed to and implemented in a plurality of physically separated components. For example, the management device 10 may be implemented by a plurality of server devices.

[0080] (Communication Unit 110) The communication unit 110 is a communication interface for communicating with another communication device (for example, another management device 10 or the communication device 30) via the APN 40. The communication unit 110 may be a network interface or may be an equipment connection interface.

[0081] For example, the communication unit 110 according to the present embodiment performs communication using an optical signal. That is, the communication unit 110 includes a circuit for transmitting and receiving an optical signal.

[0082] As described above, when the management device 10 is connected to a network other than the APN 40, the communication unit 110 may be a communication interface for connection to the network other than the APN 40. For example, the communication unit 110 may be a local area network (LAN) interface such as a network interface card (NIC), or may be a universal serial bus (USB) interface including a USB host controller, a USB port, and the like.

[0083] Further, the communication unit 110 may be a wired interface or a wireless interface. The communication unit 110 functions as communication means of the management device 10. The communication unit 110 communicates with another communication device under the control of the control unit 130.

[0084] (Storage Unit 120) The storage unit 120 is a storage device, from which data can be read and in which data can be written, such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, or a hard disk. The storage unit 120 includes a characteristic information database 121 that stores characteristic information including, for example, the static characteristic and the dynamic characteristic of the APN 40. The storage unit 120 functions as storage means of the management device 10.

[0085] Fig. 4 is a table illustrating an example of the characteristic information according to the present embodiment. The characteristic information illustrated in Fig. 4 includes static information indicating the static characteristic of the APN 40 and dynamic information indicating the dynamic characteristic of the APN 40. The static information is constant information that does not vary with time. The dynamic information is information that may vary with time.

[0086] The static information illustrated in Fig. 4 includes, for example, information indicating a start point and an end point of a path, a distance between two points, and a propagation delay time determined only by the distance. The start point and the end point of the path are, for example, information designating two adjacent nodes among the nodes A to J of the APN 40.

[0087] The distance between two points is information indicating a physical distance between the start point and the end point. In the example of Fig. 4, when the start point is the node A and the end point is the node B, the distance between two points is "200". Further, when the start point is the node A and the end point is the node C, the distance between two points is "300".

[0088] The propagation delay time determined only by the distance is a delay time determined by the distance between two points. The propagation delay time determined only by the distance is a delay time that does not vary with time. When the start point is the node A and the end point is the node B, the propagation delay time determined only by the distance between two points is "20". Further, when the start point is the node A and the end point is the node C, the propagation delay time determined only by the distance between two points is "30".

[0089] The dynamic information includes, for example, the amount of a delay increase caused by a path environment, a substantial delay time, a dispersion, a cost, and power consumption.

[0090] The amount of the delay increase caused by the path environment is information indicating a delay amount increased due to the path environment between the start point and the end point. The path environment is an environment in which the optical fiber connecting the start point and the end point is placed. Examples of the path environment include temperature, altitude / atmospheric pressure, vibration, and the like. The amount of the delay increase caused by the path environment represents a delay variation caused by the path environment.

[0091] For example, the temperature varies throughout the day. The amount of the delay increase caused by the path environment (the delay time of the path) may vary depending on the temperature. As described above, the amount of the delay increase caused by the path environment is a parameter that can vary with time.

[0092] When the start point is the node A and the end point is the node B, the amount of the delay increase caused by the path environment between two points is "1". When the start point is the node A and the end point is the node C, the amount of the delay increase caused by the path environment between two points is "5".

[0093] The substantial delay time is information indicating an actual delay time between the start point and the end point. The substantial delay time is, for example, a sum of the propagation delay time determined only by the distance and the amount of the delay increase caused by the path environment.

[0094] When the start point is the node A and the end point is the node B, the substantial delay time between two points is "21" (20 + 1). When the start point is the node A and the end point is the node C, the substantial delay time between two points is "35" (30 + 5).

[0095] The dispersion is, for example, information (parameter) indicating how large a variance of the delay time between the start point and the end point is. The dispersion includes a jitter variance and an environmental factor.

[0096] Fig. 5 is a diagram for describing an example of the dispersion according to the embodiment of the present disclosure. Fig. 5 schematically illustrates a relationship between the delay time (theoretical value) determined only by the distance and the actual delay time in consideration of a delay factor related to the path environment and a delay factor of the system related to used equipment or the like.

[0097] As illustrated in Fig. 5, a delay time obtained by adding the amount of the delay increase (the amount of the delay increase caused by the path environment) to the delay time determined only by the distance (the propagation delay time between nodes determined only by the distance) is the substantial delay time. The actual delay time is obtained by adding the jitter to the substantial delay time. The dispersion is a parameter indicating how large the jitter (delay variance) is.

[0098] A path with a large dispersion can be said to be a path with a large delay variation range, that is, a path with a large jitter amount. Alternatively, there can be a path with a small jitter amount even when the amount of the delay increase caused by the path environment is large. For example, in a case of an ideal transmission path without the jitter, the transmission delay time has a fixed value.

[0099] In order to absorb the jitter, the reception side (for example, the reception device 30R) uses a buffer. Here, a relationship between the jitter and the reception side buffer will be described with reference to Figs. 6 to 9.

[0100] Fig. 6 is a diagram illustrating an example of signal transmission according to the embodiment of the present disclosure. Fig. 6 illustrates an example of signal transmission in an ideal transmission path without the jitter.

[0101] As illustrated in Fig. 6, a signal transmitted by the transmission side (for example, the transmission device 30T) reaches the reception side (for example, the reception device 30R) with a delay time Δ. As described above, since the jitter does not occur in the ideal transmission path, the delay time Δ is constant.

[0102] Fig. 7 is a diagram illustrating an example of buffering by the reception side according to the embodiment of the present disclosure. Fig. 7 illustrates an example of buffering by the reception side in a case where signal transmission illustrated in Fig. 6 is performed.

[0103] As described above, the jitter does not occur in the ideal transmission path, and a signal propagation time from the transmission side to the reception side is the same constant value (propagation time Δ) as the delay time. If the delay amount (delay time Δ) does not vary and is constant as described above, the reception side does not need to smooth a signal arrival time by buffering.

[0104] For example, it is assumed that data transmitted from the transmission side is image data, and the reception side displays the image data on a display. In this case, if the delay time Δ does not vary and is constant, the reception side can display the image data on the display with the delay time Δ without buffering, and can maintain continuity of image display.

[0105] As described above, in a case of the ideal transmission path without the jitter, the transmission delay time has a fixed value, and thus buffering for jitter absorption by the reception side is unnecessary.

[0106] Fig. 8 is a diagram illustrating another example of the signal transmission according to the embodiment of the present disclosure. Fig. 8 illustrates an example of the signal transmission in a transmission path in which the jitter occurs.

[0107] As illustrated in Fig. 8, a signal transmitted by the transmission side (for example, the transmission device 30T) reaches the reception side (for example, the reception device 30R) with a delay. In the example of Fig. 8, since the jitter occurs, the delay amount varies with time. The delay amount varies within a range of ±α, for example.

[0108] Fig. 9 is a diagram illustrating an example of buffering by the reception side according to the embodiment of the present disclosure. Fig. 9 illustrates an example of buffering by the reception side in a case where signal transmission illustrated in Fig. 8 is performed.

[0109] As described above, the jitter occurs in the actual transmission path. Therefore, the signal propagation time from the transmission side to the reception side varies within a range of ±α (propagation time Δ±α).

[0110] As described above, when the jitter occurs, the reception side smooths the signal arrival time by buffering. The reception side temporarily accumulates packets to ensure continuous supply of data so that the buffer does not overflow or underflow even when a packet (signal) arrival time varies by α hours before and after the packet (signal) arrival time.

[0111] At this time, a time during which a signal is stored in the buffer on the reception side (buffer residence time β) is much longer than the variance α of the delay amount (β >> α).

[0112] For example, it is assumed that data transmitted from the transmission side is image data, and the reception side displays the image data on a display. In this case, when the delay time Δ varies within the range of ±α, the reception side needs to buffer a received signal with the buffer residence time β, and thus the image data is displayed on the display with a delay time Δ + β.

[0113] As a result, the reception side can maintain continuation of image display even when the jitter occurs.

[0114] As described above, since the jitter exists in the actual transmission path, the packet arrival time varies on the reception side. In order to smooth such a variation, buffering is required on the reception side.

[0115] In a case where the delay variation (α) occurs at a high frequency, the reception side can absorb the jitter with a buffer having a small capacity. On the other hand, in a case where the delay variation (α) occurs at a low frequency, the reception side needs to use a buffer having a large capacity to absorb the jitter.

[0116] Therefore, in a case where the delay variation (α) occurs at a low frequency, the delay (β) due to buffering on the reception side increases. As described above, as more detailed characteristics of the delay variation, a frequency distribution may be considered in addition to the dispersion of the delay variation. That is, the frequency distribution of the delay variation may be included as the dynamic information.

[0117] Returning to Fig. 4, the dispersion indicates, for example, the variation range α of the delay time described above. In the example of Fig. 4, when the start point is the node A and the end point is the node B, dispersion between the two points is "0.1". Further, when the start point is the node A and the end point is the node C, dispersion between the two points is "0.7".

[0118] As described above, the dynamic information includes the cost. The cost is, for example, a cost generated when the transmission path is used. The cost includes a line usage fee and the like.

[0119] In addition, the dynamic information includes the power consumption. The power consumption is, for example, power consumed at the time of signal transmission. For example, the power consumption is power consumption in processing for transmitting a signal. For example, in a case where a signal is greatly attenuated when being transmitted through the transmission path, the power consumption increases.

[0120] In a case where the cost and / or power consumption do not vary (or vary little) in a short term, the cost and / or the power consumption may be included in the static information.

[0121] As described above, the characteristic information database 121 holds, for example, characteristics (characteristic information) of a path between two adjacent points illustrated in Fig. 4.

[0122] Fig. 4 illustrates the characteristic information in a case where a forward path and a return path between two adjacent points have the same characteristics. When the characteristics of the APN 40 are different between the forward path and the return path, the characteristic information database 121 holds the characteristic information of each of the forward path and the return path.

[0123] The characteristic information is updated periodically or when the status of the APN 40 changes. The characteristic information is updated in real time, for example. In addition, each piece of information (parameter) illustrated in Fig. 4 uses a relative value as an example, and a unit thereof is not particularly specified.

[0124] In addition, here, the characteristic information includes characteristics between adjacent nodes, but the characteristic information is not limited thereto. For example, the characteristic information database 121 may hold the characteristic information including characteristics of a path between a transmission node and a reception node.

[0125] Fig. 10 is a table illustrating another example of the characteristic information according to the present embodiment. Fig. 10 illustrates a list of some of paths that can be taken in a case where the transmission node is the node A and the reception node is the node I. In Fig. 10, a path whose distance is obviously longer than those of other paths (for example, a path whose a distance is longer than a predetermined value) is not illustrated.

[0126] The characteristic information illustrated in Fig. 10 includes the static information indicating the static characteristic of the APN 40 and the dynamic information indicating the dynamic characteristic of the APN 40. The static information includes, for example, a path from the node A to the node I and a path distance. The dynamic information includes a substantial delay time and dispersion.

[0127] For example, "A-C-G-I" in Fig. 10 is a path from the node A to the node I via the nodes C and G. This path includes a path between the node A and the node C, a path between the node C and the node G, and a path between the node G and the node I.

[0128] For example, in the APN 40 according to the present embodiment, a distance between the node A and the node C is 300, a distance between the node C and the node G is 500, and a distance between the node G and the node I is 200 (see Fig. 4). Therefore, a path distance of "A-C-G-I" is 300 + 500 + 200 = 1000.

[0129] In addition, in the APN 40 according to the present embodiment, a substantial delay time between the node A and the node C is 35, a substantial delay time between the node C and the node G is 53, and a substantial delay time between the node G and the node I is 21 (see Fig. 4). Therefore, a substantial delay time of "A-C-G-I" is 35 + 53 + 21 = 109.

[0130] In addition, in the APN 40 according to the present embodiment, a dispersion between the node A and the node C is 0.7, a dispersion between the node C and the node G is 0.2, and a dispersion between the node G and the node I is 0.2 (see Fig. 4). Therefore, a dispersion of "A-C-G-I" is 0.7 + 0.2 + 0.2 = 1.1.

[0131] As described above, the characteristics of the path between the transmission node and the reception node are obtained as the sum of the characteristics of the path connecting the nodes included in the path.

[0132] In this manner, the characteristic information database 121 may hold the characteristics (characteristic information) of the path between the transmission and reception nodes illustrated in Fig. 10, for example.

[0133] For example, the management device 10 may cause the characteristic information database 121 to hold the characteristic information with a node at which the management device 10 is disposed as a starting point (transmission node).

[0134] The characteristic information is updated periodically or when the status of the APN 40 changes. The characteristic information is updated in real time, for example. In addition, each piece of information (parameter) illustrated in Fig. 10 uses a relative value as an example, and a unit thereof is not particularly specified.

[0135] (Control Unit 130) Returning to Fig. 3, the control unit 130 is a controller that controls each unit of the management device 10. The control unit 130 is implemented by, for example, a processor such as a central processing unit (CPU), a micro processing unit (MPU), or a graphics processing unit (GPU). For example, the control unit 130 is implemented in a manner in which the processor executes various programs stored in the storage device inside the management device 10 by using a RAM or the like as a work area. Note that the control unit 130 may be implemented by an integrated circuit such as an ASIC or a FPGA. The CPU, the MPU, the GPU, the ASIC, and the FPGA can all be regarded as the controller.

[0136] As illustrated in Fig. 3, the control unit 130 includes a request acquisition unit 131, a characteristic acquisition unit 132, a generation unit 133, and a notification unit 134. Each block (the request acquisition unit 131, the notification unit 134, or the like) included in the control unit 130 is a functional block indicating a function of the control unit 130. These functional blocks may be software blocks or hardware blocks. For example, each of the above-described functional blocks may be one software module implemented by software (including a microprogram) or may be one circuit block on a semiconductor chip (die). It is a matter of course that each functional block may be one processor or one integrated circuit. A method of configuring the functional block is arbitrary. Note that the control unit 130 may be configured with a functional unit different from the above-described functional block. The internal configuration of the control unit 130 is not limited to the configuration illustrated in Fig. 3, and may be another configuration as long as the processing described below is performed.

[0137] (Request Acquisition Unit 131) The request acquisition unit 131 acquires a notification for requesting the dynamic characteristic information from the communication device 30 via the API defined in the communication system. The request acquisition unit 131 instructs the characteristic acquisition unit 132 to acquire the dynamic characteristic corresponding to the acquired request.

[0138] (Characteristic Acquisition Unit 132) The characteristic acquisition unit 132 acquires information regarding the dynamic characteristic from the characteristic information database 121 according to the instruction from the request acquisition unit 131. The characteristic acquisition unit 132 notifies the generation unit 133 of the acquired dynamic characteristic.

[0139] (Generation Unit 133) The generation unit 133 generates the dynamic characteristic information based on the dynamic characteristic. For example, the generation unit 133 generates the dynamic characteristic information including the dynamic characteristic requested by the communication device 30 among the dynamic characteristics acquired by the characteristic acquisition unit 132.

[0140] Alternatively, the generation unit 133 may generate the dynamic characteristic information including a communication path satisfying a condition designated by the communication device 30.

[0141] The generation unit 133 generates the dynamic characteristic information according to the request from the communication device 30. The generation unit 133 outputs the generated dynamic characteristic information to the notification unit 134.

[0142] (Notification Unit 134) The notification unit 134 notifies the communication device 30 of the dynamic characteristic information generated by the generation unit 133.

[0143] In addition, when an event occurs in the APN 40, the notification unit 134 notifies the communication device 30 of the event. For example, in a case where the dynamic characteristic of the communication path used by the communication device 30 for data transmission has changed, the notification unit 134 notifies the communication device 30 of the change.

[0144] For example, in a case where the condition designated by the communication device 30 is satisfied, the notification unit 134 notifies the communication device 30 of the event. Examples of the condition designated by the communication device 30 include the type of the characteristic (for example, the delay time or the jitter amount) and a characteristic variation (for example, an increased delay time or a jitter amount exceeding a designated value).

[0145] In this manner, the management device 10 may notify the dynamic characteristic information in response to the request from the communication device 30 via the API, or may notify the communication device 30 of an event with occurrence of the event such as a change of the dynamic characteristic as a trigger.

[0146] <2-3. Example of Configuration of Communication Device> The communication device 30 is an information processing device that communicates with another communication device 30 via the APN 40. The communication device 30 can be, for example, a mobile phone, a smart device (smartphone or tablet PC), a personal digital assistant (PDA), a personal computer, or a camera. The communication device 30 may be a head mounted display having a function of wirelessly transmitting and receiving data, VR goggles, or the like. The communication device 30 may be an information processing device having a function of executing an application.

[0147] The communication device 30 is connected to the APN 40, for example, by being connected to the management device 10. Alternatively, the communication device 30 may be connected to the APN 40 directly or by being connected to a device different from the management device 10. In this case, the communication device 30 accesses the management device 10 to acquire the dynamic characteristic information regarding the dynamic characteristic of the APN 40.

[0148] Fig. 11 is a block diagram illustrating an example of a configuration of the communication device 30 according to the embodiment of the present disclosure. The communication device 30 includes a communication unit 310, a storage unit 320, and a control unit 330.

[0149] Note that the configuration illustrated in Fig. 11 is a functional configuration, and a hardware configuration may be different from this. Furthermore, the functions of the communication device 30 may be statically or dynamically distributed to and implemented in a plurality of physically separated components.

[0150] (Communication Unit 310) The communication unit 310 is a communication interface for communicating with another communication device (for example, the management device 10 or another communication device 30) via the APN 40. The communication unit 310 may be a network interface or may be an equipment connection interface.

[0151] For example, the communication unit 310 according to the present embodiment may perform communication using an optical signal. That is, the communication unit 310 may include a circuit for transmitting and receiving an optical signal.

[0152] As described above, when the communication device 30 is connected to a network other than the APN 40, the communication unit 310 may be a communication interface for connection to the network other than the APN 40. For example, the communication unit 310 may be a local area network (LAN) interface such as a network interface card (NIC), or may be a USB interface including a USB host controller, a USB port, and the like.

[0153] Further, the communication unit 310 may be a wired interface or a wireless interface. The communication unit 310 functions as communication means of the communication device 30. The communication unit 310 communicates with other communication devices under the control of the control unit 330.

[0154] (Storage Unit 320) The storage unit 320 is a storage device, from which data can be read and in which data can be written, such as a DRAM, an SRAM, a flash memory, or a hard disk. The storage unit 320 functions as storage means of the communication device 30.

[0155] (Control Unit 330) The control unit 330 is a controller that controls each unit of the communication device 30. The control unit 330 is implemented by, for example, a processor such as a CPU, an MPU, or a GPU. For example, the control unit 330 is implemented in a manner in which the processor executes various programs stored in the storage device inside the management device 10 by using a RAM or the like as a work area. Note that the control unit 330 may be implemented by an integrated circuit such as an ASIC or a FPGA. The CPU, the MPU, the GPU, the ASIC, and the FPGA can all be regarded as the controller.

[0156] As illustrated in Fig. 11, the control unit 330 includes an information acquisition unit 331, a path selection unit 332, and a communication control unit 333. Each block (the information acquisition unit 331, the communication control unit 333, or the like) included in the control unit 330 is a functional block indicating a function of the control unit 330. These functional blocks may be software blocks or hardware blocks. For example, each of the above-described functional blocks may be one software module implemented by software (including a microprogram) or may be one circuit block on a semiconductor chip (die). It is a matter of course that each functional block may be one processor or one integrated circuit. A method of configuring the functional block is arbitrary. Note that the control unit 330 may be configured with a functional unit different from the above-described functional block. The internal configuration of the control unit 330 is not limited to the configuration illustrated in Fig. 11, and may be another configuration as long as the processing described below is performed.

[0157] The control unit 330 also functions as an application execution unit. The control unit 330 is operated as an application to provide an application service to the user. Each unit (the information acquisition unit 331, the communication control unit 333, or the like) of the control unit 330 can be operated as a function of the application.

[0158] (Information Acquisition Unit 331) The information acquisition unit 331 requests the management device 10 for the dynamic characteristic information via the API defined in the communication system. The information acquisition unit 331 acquires the requested dynamic characteristic information from the management device 10. The information acquisition unit 331 outputs the acquired dynamic characteristic information to the path selection unit 332.

[0159] (Path Selection Unit 332) The path selection unit 332 selects a path for data transmission based on the dynamic characteristic information. For example, in a case where the dynamic characteristic information includes the delay time (for example, the substantial delay time) and the jitter (for example, the dispersion), the path selection unit 332 selects a path that satisfies a communication quality (for example, low delay and / or low jitter) required for data to be transmitted.

[0160] On the other hand, in a case where the dynamic characteristic information includes information regarding a path that satisfies a required condition (communication quality) as described below, the path selection unit 332 selects, for example, a path included in the dynamic characteristic information as a path to be used for data transmission.

[0161] The path selection unit 332 outputs the selected path to the communication control unit 333.

[0162] (Communication Control Unit 333) The communication control unit 333 controls the communication unit 310 to transmit data through the path selected by the path selection unit 332.

[0163] <<3. Example of API>> Next, an example of the API and an event notification defined in the communication system according to the present embodiment will be described. The API and the event described here are examples, and the API and the event defined in the communication system are not limited to those described here. An API and an event other than the API and the event described herein may be defined in the communication system, or at least one of the API or the event described herein does not have to be defined in the communication system.

[0164] The API according to the present embodiment is a program module that obtains a return value when a function is called by providing one or a plurality of arguments. The example described here is an implementation example of an API specification, and similar functions can be expressed in different grammars.

[0165] For example, a true value described below may be represented as a pointer to a memory address where the value is stored, an object, or a member of a class. In addition, the type of a variable described below is not particularly limited, and any type can be used.

[0166] <3-1. SetDeliveryPath()> Fig. 12 is a diagram for describing an example of the API according to the embodiment of the present disclosure. This API, SetDeliveryPath(), is an API that designates a destination node to which data is to be sent, designates a desired characteristic for a path, and provides a path satisfying the condition to the application.

[0167] SetDeliveryPath() has a role of establishing a network path with the designated characteristic. That is, the communication device 30 can use this API to establish a network path with a desired characteristic.

[0168] SetDeliveryPath() takes, for example, DestinationNode, Mode, and PathID as arguments. DestinationNode is an argument indicating a data transmission destination node. DestinationNode represents an address that can uniquely specify a node on the network. The management device 10 specifies a destination node based on this argument and establishes a communication path.

[0169] Mode is an argument designating the dynamic characteristic. For example, a value of 1 to 5 is designated as Mode. "1" designates a mode prioritizing delay reduction. When "1" is set as Mode, the management device 10 selects a path for data transmission to the destination node (a node set in DestinationNode) by prioritizing the minimum delay time.

[0170] "2" designates a mode prioritizing synchronization stability by stabilization of the PLL. When "2" is set as Mode, the management device 10 selects a path for data transmission to the destination node based on the minimum packet jitter. That is, the management device 10 selects a path with the minimum delay jitter amount.

[0171] "3" designates a mode prioritizing low cost. When "3" is set as Mode, the management device 10 selects a path for data transmission to the destination node based on the minimum cost (charging). That is, the management device 10 selects a path with the minimum cost (a charge by charging).

[0172] "4" designates a mode prioritizing ecology. When "4" is set as Mode, the management device 10 selects a path for data transmission to the destination node based on the minimum power consumption. That is, the management device 10 selects a path with the minimum power consumption.

[0173] "5" is set particularly in a case where the condition of the dynamic characteristic is not designated. When "5" is set as Mode, the management device 10 selects an arbitrary path from currently available network paths.

[0174] Here, the application designates the condition such as the minimum delay time or the minimum jitter as the dynamic characteristic, but the condition is not limited thereto. For example, the application may designate the condition by using a specific numerical value. For example, the application may designate the condition of the dynamic characteristic by specifically limiting a numerical value such as the delay time being equal to or less than a predetermined time or the jitter value being equal to or less than a predetermined value.

[0175] In a case where the management device 10 can establish a path satisfying the condition, an ID uniquely designating the path is substituted into PathID. The communication device 30 designates a path with PathID when checking a status of the path. PathID can correspond to, for example, the dynamic characteristic information described above.

[0176] The management device 10 notifies the communication device 30 of ret as a return value of SetDeliveryPath(). The return value can correspond to, for example, the dynamic characteristic information described above. Alternatively, an ID uniquely designating a path set in PathID may correspond to the dynamic characteristic information. ret is a return value representing a result of path search by the management device 10. For example, a value of 0 or 1 is set as ret.

[0177] When "0" is set as the return value, the return value indicates that the management device 10 can establish a path satisfying the condition. When "1" is set as the return value, the return value indicates that the management device 10 cannot establish a path satisfying the condition.

[0178] As described above, SetDeliveryPath() has a function of preferentially selecting a path having a characteristic designated with Mode by the application. When path selection by the management device 10 is successful, 0 is returned as ret, and a value specifying the path is set as PathID.

[0179] When the application (or an application creator) selects Mode corresponding to a use case (for example, moving image distribution) of the application and executes SetDeliveryPath(), the management device 10 on the network side providing the API automatically selects a path corresponding to the use case.

[0180] As described above, in the communication system according to the present embodiment, the application selects Mode corresponding to a use case and executes this API, so that the management device 10 automatically selects and secures a path according to the application and provides an optimal path for the application.

[0181] Therefore, even in a case where the application creator does not have knowledge about which condition of the dynamic characteristic (for example, low delay) is satisfied when which path is selected, that is, knowledge about the selection method, the application can perform data transmission through an optimal communication path.

[0182] <3-2. GetPathList()> Fig. 13 is a diagram for describing another example of the API according to the embodiment of the present disclosure. This API, GetPathList(), is an API that can be used by the application to acquire a list of paths from SourceNode to DestinationNode.

[0183] GetPathList() has a role of acquiring the list of the paths from SourceNode to DestinationNode. That is, the communication device 30 can use this API to acquire a list of paths from a source node to a destination node.

[0184] GetPathList() takes, for example, SourceNode and DestinationNode as arguments. SourceNode is an optional argument.

[0185] SourceNode is an argument indicating a data transmission source node. A value (for example, a source address) that uniquely designates the source node is set in SourceNode. When SourceNode is omitted, a node at which the application is executed (that is, a node to which the communication device 30 that executes the application is connected) is set as a transmission source.

[0186] DestinationNode is an argument indicating a data transmission destination (destination) node. DestinationNode represents an address that can uniquely specify a node on the network.

[0187] The management device 10 notifies the communication device 30 of PathIDList as a return value of GetPathList(). The return value can correspond to, for example, the dynamic characteristic information described above. PathIDList is a list uniquely representing the number of paths and paths from SourceNode to DestinationNode.

[0188] As described above, GetPathList() has a function of specifying paths from SourceNode to DestinationNode as a list. The application acquires the list of the paths from SourceNode to DestinationNode by using this API. The application may search for (select) a path having a desired characteristic from the list, and perform data communication on the path.

[0189] In a case where the application selects a path not by automatic selection by SetDeliveryPath() but by an application-side unique algorithm, it is possible to first know what kind of path exists by using GetPathList(). The application can determine, based on the list, an optimal path corresponding to a use after examining information and the status of each path.

[0190] <3-3. GetPathStatus()> Fig. 14 is a diagram for describing another example of the API according to the embodiment of the present disclosure. This API, GetPathStatus(), is an API that provides the status of a path to the application.

[0191] GetPathStatus() has a role of acquiring information regarding the status of the network path designated by the argument PathID. That is, the communication device 30 can use this API to acquire information regarding a status of a desired path.

[0192] GetPathStatus() takes, for example, PathID as an argument. PathID is a value uniquely designating a path.

[0193] The management device 10 notifies the communication device 30 of PathStatus as a return value of GetPathStatus(). The return value can correspond to, for example, the dynamic characteristic information described above. PathStatus is a return value representing the status of the network path. For example, a value of 0 to 4 is set as a value indicating the status.

[0194] "0" indicates that the designated path is active (usable). "1" indicates that the designated path is using (being used by the corresponding application). That is, in a case where the return value of GetPathStatus() is "1", the application that has transmitted GetPathStatus() is using the path designated by the argument PathID.

[0195] "2" indicates that the designated path is occupied (being used by another application). That is, in a case where the return value of GetPathStatus() is "2", an application different from the application that has transmitted GetPathStatus() is using the path designated by the argument PathID.

[0196] "3" indicates that the designated path is unselectable (unselectable by the corresponding application). That is, in a case where the return value of GetPathStatus() is "3", the application that has transmitted GetPathStatus() cannot select the path designated by the argument PathID.

[0197] "4" indicates that the designated path is unusable (unusable). That is, when the return value of GetPathStatus() is "4", the path designated by the argument PathID cannot be used due to a failure or the like.

[0198] As described above, GetPathStatus() has a function of checking the status of a path (for example, whether or not the path can be selected) such as whether the network path designated by PathID can be selected by the application.

[0199] The application can check the status of a designated network path by designating the network path and executing GetPathStatus().

[0200] <3-4. GetPathInformation()> Fig. 15 is a diagram for describing another example of the API according to the embodiment of the present disclosure. This API, GetPathInformation(), is an API that can be used by the application to acquire the dynamic characteristic (for example, a parameter related to the delay or jitter) of a transmission path.

[0201] GetPathInformation() has a role as an API that returns network characteristic information. That is, the communication device 30 can use this API to acquire the dynamic characteristic of a network path.

[0202] GetPathInformation() takes, for example, PathID as an argument. PathID is an optional argument. PathID takes a value that designates a network path whose characteristic information of the dynamic characteristic is desired to be known. When PathID is omitted, it is considered that PathID of a path currently used by the application is designated.

[0203] The management device 10 notifies the communication device 30 of an array or a pointer indicating a memory area in which network status information (dynamic characteristic) is stored, for example, as a return value of GetPathInformation(). The return value can correspond to, for example, the dynamic characteristic information described above. The network status information includes, for example, at least one of PathID, the substantial delay time, a dispersion value (jitter value) of the delay variation, the cost, the power consumption, or the like.

[0204] As described above, GetPathInformation() has a function of acquiring the characteristic information of a path designated by PathID. The application acquires the dynamic characteristic including the delay time, the jitter value, and the like of the path designated by PathID by using this API.

[0205] In this manner, the application can acquire information regarding the dynamic characteristic of a path by designating the path whose parameter regarding the dynamic characteristic is desired to be acquired with PathID and executing GetPathInformation().

[0206] Note that a method of calculating the dynamic characteristic depends on implementation on the network side (for example, the management device 10). The management device 10 calculates a return value of GetPathInformation() by referring to, for example, the characteristic information database 121.

[0207] As described above, in the APN 40, the dynamic characteristic is largely determined by the static characteristic of the path, and a variation range thereof is also small. Therefore, the management device 10 can estimate the dynamic characteristic of the APN 40 with higher accuracy.

[0208] Therefore, the management device 10 can notify the application of a reliable return value that can serve as a determination criterion when the application side selects a path.

[0209] Furthermore, for example, a time range of measurement of the delay time and the jitter value which are examples of the dynamic characteristic depends on implementation on the network side. The management device 10 may notify the application of, for example, the fixed worst value at the time of design as the delay time or jitter value. Alternatively, the management device 10 may calculate the delay time and the jitter value based on an actual measurement value in a certain time range such as the latest several minutes.

[0210] Furthermore, here, GetPathInformation() is an API that simultaneously notifies the application of a plurality of parameters such as the delay time and the jitter value, but the API for acquiring the dynamic characteristic is not limited thereto.

[0211] For example, in the communication system, an API for individually acquiring each parameter of the dynamic characteristic, such as an API for acquiring the delay time or an API for acquiring the jitter value, may be defined.

[0212] <3-5. ChangePathStatus()> Fig. 16 is a diagram for describing another example of the API according to the embodiment of the present disclosure. This API, ChangePathStatus(), is an API that can be used by the application to set, for example, the status of the path designated by PathID to be usable (selectable) or unusable.

[0213] ChangePathStatus() has a role as an API that changes the status of a network path. That is, the communication device 30 can use this API to change the status of a network path.

[0214] ChangePathStatus() takes, for example, PathID and PathStatus as arguments. PathID takes a value that designates a network path whose status is desired to be changed.

[0215] PathStatus takes a value that designates the status of a network path. For example, PathStatus is used to set the path designated by PathID to be selectable or unselectable. The path set to be unselectable by the application is explicitly excluded from automatic path selection options in SetDeliveryPath() described above.

[0216] For example, a value of 0 or 1 is set as PathStatus. "0" indicates selectable (active). That is, when "0" is set as PathStatus, the path designated by PathID is set to be selectable. "1" indicates unselectable. That is, when "1" is set as PathStatus, the path designated by PathID is set to be unselectable.

[0217] The management device 10 notifies the communication device 30 of ret as a return value of ChangePathStatus(). The return value can correspond to, for example, the dynamic characteristic information described above. ret represents a result of changing the status of the path. For example, a value of 0 or 1 is set as ret.

[0218] When "0" is set as the return value, the return value indicates succeeded, that is, indicates that the change of the status of the path designated by PathID is successful. When "1" is set as the return value, the return value indicates failed, that is, indicates that the change of the status of the path designated by PathID is failed. For example, in a case where the path designated by PathID is being used by another application or is in an unusable state due to a failure or the like, the change of the status of the path to selectable (active) is failed, and "1" is set as the return value.

[0219] As described above, ChangePathStatus() has a role of setting the network path with the designated PathID to be selectable (usable) or unselectable by the application in a network use of the application that issues this API.

[0220] The application can explicitly set a specific path to be unselectable by using this API. As a result, the application can narrow down path options at the time of executing SetDeliveryPath(), and a path having a dynamic characteristic desired by the application can be easily automatically selected. In this way, the application can control automatic path selection to some extent by using ChangePathStatus().

[0221] <3-6. SetPath()> Fig. 17 is a diagram for describing another example of the API according to the embodiment of the present disclosure. This API, SetPath(), is an API that can be used by the application to secure a path designated by PathID.

[0222] SetPath() has a role of setting a network path to be used by the application. That is, the communication device 30 can use this API, for example, to use a network path for communication.

[0223] SetPath() takes, for example, PathID as an argument. PathID takes a value that designates a network path to be used by the application.

[0224] The management device 10 notifies the communication device 30 of ret as a return value of SetPath(). The return value can correspond to, for example, the dynamic characteristic information described above. ret represents a result of securing the network path designated by PathID. For example, a value of 0 or 1 is set as ret.

[0225] When "0" is set as the return value, the return value indicates succeeded, that is, indicates that the path designated by PathID has been successfully secured. When "1" is set as the return value, the return value indicates failed, that is, indicates that the path designated by PathID has not been secured.

[0226] As described above, SetPath() has a role of allowing the application that issues this API to occupy the network path with PathID designated as the argument and to be used for data transmission.

[0227] The application can use this API to secure a network path (communication path) to be used for data transmission. As a result, the application can start data transmission by using the secured network path.

[0228] <3-7. OnPathChanged> This event, OnPathChanged, is an event that notifies that a path usable by the application has been set or that a path that is being used by the application has been automatically changed due to a network failure or the like.

[0229] For example, when a network path to be used by the application is set by SetDeliveryPath() or SetPath(), an event that notifies the application side of the status change occurs. Alternatively, when the path used by the application is automatically changed due to a network failure or the like, an event of notifying the application side of the status change occurs. When the event occurs, the management device 10 notifies the application of the event.

[0230] When this event occurs and the notification of the occurrence is received, handling is left to the application side. That is, when this event occurs, the application can take an arbitrary measure such as checking the status of the path and changing the path as necessary or stopping data transmission.

[0231] <<4. Processing Example>> Next, a processing example performed in the communication system according to the present embodiment will be described.

[0232] <4-1. Communication Processing> Fig. 18 is a diagram for describing an example of communication processing according to the embodiment of the present disclosure. Fig. 18 illustrates communication processing in a case where the transmission device 30T transmits data to the reception device 30R. In addition, here, the transmission device 30T is connected to the network node (node) A, and the reception device 30R is connected to the network node (node) I.

[0233] The management device 10 is disposed at each node of the APN 40. In the example of Fig. 18, the first management device 10_1 is disposed at the network node A, and the second management device 10_2 is disposed at the network node I.

[0234] First, the transmission device 30T acquires the dynamic characteristic information for the first management device 10_1 disposed at the network node A by using the API (Step S1). For example, the transmission device 30T executes the API SetDeliveryPath() described above to select and set a communication path satisfying a desired dynamic characteristic.

[0235] That is, the transmission device 30T designates a condition of the dynamic characteristic required for data transmission and requests the first management device 10_1 to set a path and notify of PathID. The first management device 10_1 sets the path satisfying the condition of the dynamic characteristic designated by the transmission device 30T among the paths from the transmission device 30T and the reception device 30R, that is, the node A to the node I. The first management device 10_1 notifies the transmission device 30T of the successful setting and an ID (PathID) for identifying the set path as the dynamic characteristic information.

[0236] The transmission device 30T transmits data to the reception device 30R through the communication path set by the first management device 10_1 (Step S2).

[0237] In addition, when an event occurs, for example, in a case where the set path become unusable due to a failure or the like, the first management device 10_1 notifies the transmission device 30T of the event (Step S3).

[0238] Upon receiving the event notification, the transmission device 30T performs processing such as stopping data transmission and resetting a path.

[0239] In this manner, the transmission device 30T sets a path satisfying a desired dynamic characteristic by using the API and communicates with the reception device 30R. As a result, the transmission device 30T can perform data communication by using the characteristics of the APN 40.

[0240] Here, the transmission device 30T requests the first management device 10_1 to set a path satisfying a desired dynamic characteristic, but the path setting method is not limited thereto.

[0241] For example, the transmission device 30T may acquire a list of paths from the transmission device 30T (source node) to the reception device 30R (destination node) from the first management device 10_1 by using GetPathList().

[0242] The transmission device 30T uses, for example, GetPathStatus() or GetPathInformation() to select a path to be used for communication from selectable paths that satisfy a desired dynamic characteristic. The transmission device 30T secures a path selected using SetPath(), for example.

[0243] In this manner, the transmission device 30T may directly instruct the first management device 10_1 to secure a path to be used for communication. In this case, the transmission device 30T can perform data communication utilizing the characteristics of the APN 40 by acquiring information (dynamic characteristic information) regarding the dynamic characteristic from the first management device 10_1 using GetPathInformation().

[0244] Although the transmission device 30T selects a path for data communication here, the reception device 30R may select a path. In this case, for example, the reception device 30R executes the API for the second management device 10_2 to select and set a path. The reception device 30R notifies the transmission device 30T of information regarding the set path (for example, PathID). As a result, the transmission device 30T can perform data communication using the path set by the reception device 30R.

[0245] Alternatively, the reception device 30R may select a path, and the transmission device 30T may set the path. As described above, the communication device 30 that selects a path and the communication device 30 that sets a path may be different from each other.

[0246] <4-2. Automatic Path Selection Processing> Fig. 19 is a flowchart illustrating an example of a flow of automatic path selection processing according to the embodiment of the present disclosure. The automatic path selection processing illustrated in Fig. 19 is performed prior to the start of data communication by the communication device 30 functioning as the application, for example.

[0247] First, the communication device 30 sets an address of a destination node in DestinationNode which is the argument of the API SetDeliveryPath() (Step S101).

[0248] Next, the communication device 30 determines Mode matching a desired path characteristic (a dynamic characteristic of a path) (Step S102).

[0249] The communication device 30 calls the API SetDeliveryPath() (Step S103). Accordingly, the communication device 30 executes SetDeliveryPath() with the arguments set in Steps S101 and S102.

[0250] The communication device 30 determines whether or not the execution of the API has normally ended (Step S104). For example, the communication device 30 determines whether or not the execution of the API has normally ended according to the return value (the value of ret) of SetDeliveryPath().

[0251] When the value of ret is 1 and the API has not normally ended (Step S104; No), the communication device 30 changes the value set as Mode (Step S105), and returns to Step S103.

[0252] When the value of ret is 0 and the API has normally ended (Step S104; Yes), the communication device 30 acquires the value of PathID of the selected path (Step S106), and ends the processing.

[0253] As described above, the communication device 30 can automatically select a path having a desired dynamic characteristic by executing SetDeliveryPath().

[0254] <4-3. Path Setting Processing> Fig. 20 is a flowchart illustrating an example of a flow of path setting processing according to the embodiment of the present disclosure. The path setting processing illustrated in Fig. 20 is performed prior to the start of data communication by the communication device 30 functioning as the application, for example.

[0255] First, the communication device 30 executes GetPathList() to acquire information regarding a path between a source node (SourceNode) and a destination node (DestinationNode) (Step S201).

[0256] The communication device 30 acquires characteristics of the paths listed in the acquired PathIDList by GetPathInformation() (Step S202).

[0257] The communication device 30 determines a path (PathID) matching a desired path characteristic (Step S203). The communication device 30 calls the API GetPathStatus() using the determined path (PathID) as an argument (Step S204).

[0258] The communication device 30 determines whether or not the path designated by PathID is active based on a result of the execution of GetPathStatus() (Step S205).

[0259] In a case where the path designated by PathID is not active (Step S205; No), the communication device 30 determines another path (PathID) matching the desired path characteristic (Step S206), and returns to Step S204.

[0260] On the other hand, in a case where the path designated by PathID is active (Step S205; Yes), the communication device 30 executes SetPath() to designate a path to be used for data transmission (Step S207).

[0261] In this manner, the communication device 30 may explicitly designate a path by using PathIDList.

[0262] Here, the communication device 30 determines a path matching the path characteristic and confirms the status of the determined path, but the path setting processing performed by the communication device 30 is not limited thereto. For example, the communication device 30 may extract a path that is active from among the paths listed in the acquired PathIDList, and determine a path matching a desired dynamic characteristic from among the extracted paths.

[0263] <4-4. Event Processing> Fig. 21 is a flowchart illustrating an example of a flow of event processing according to the embodiment of the present disclosure. The event processing illustrated in Fig. 21 is performed when, for example, the communication device 30 functioning as the application receives an event notification from the management device 10. Furthermore, here, the communication device 30 receives the event OnPathChanged as the event notification.

[0264] Upon receiving the event OnPathChanged, the communication device 30 executes, for example, GetPathInfomation() to acquire the characteristic information (dynamic characteristic) of a path that has been automatically changed, that is, a path that is currently being selected (Step S301).

[0265] The communication device 30 determines whether or not the automatically changed path satisfies a desired characteristic based on the acquired characteristic information (Step S302).

[0266] In a case where the automatically changed path satisfies the desired characteristic (Step S302; Yes), the communication device 30 continues data transmission through the automatically selected path (Step S303).

[0267] In a case where the automatically changed path does not satisfy the desired characteristic (Step S302; No), the communication device 30 determines another path (PathID) matching the desired path characteristic (dynamic characteristic) (Step S304). The communication device 30 determines another path, for example, similarly to the path setting processing of Fig. 20.

[0268] Next, the communication device 30 designates a path to be used for data transmission by SetPath() (Step S305). The communication device 30 designates another path (PathID) determined in Step S304 by SetPath().

[0269] As a result, even when the communication path is automatically changed due to a failure or the like, the communication device 30 can continue data transmission through the communication path satisfying the desired dynamic characteristic.

[0270] The processing in the communication device 30 after the event notification is performed is arbitrary. Therefore, processing other than the processing illustrated in Fig. 21 may be performed. For example, upon receiving the event notification, the communication device 30 may stop data transmission regardless of the dynamic characteristic of the automatically selected path.

[0271] Alternatively, upon receiving the event notification, the communication device 30 may stop data transmission in a case where a path satisfying the desired dynamic characteristic cannot be set. Furthermore, upon receiving the event notification, the communication device 30 may continue data transmission by using, for example, a path that does not satisfy the desired dynamic characteristic even in a case where a path that satisfies the desired dynamic characteristic cannot be set.

[0272] The communication device 30 may determine an operation after the event notification according to, for example, the application to be executed.

[0273] As described above, the communication device 30 according to the present embodiment communicates with another communication device 30 via an optical network (for example, the APN 40). The communication device 30 includes the control unit 330.

[0274] The control unit 330 requests the management device 10 disposed at a node of the optical network and managing a dynamic characteristic of a transmission path of the optical network to transmit dynamic characteristic information regarding the dynamic characteristic of a communication path with another communication device 30 by using the API.

[0275] The control unit 330 acquires the dynamic characteristic information from the management device 10.

[0276] As a result, the communication device 30 can perform communication according to the characteristics of the optical network.

[0277] <<5. Other Embodiments>> The above-described embodiments show only examples, and various modifications and applications are possible. The processing according to each embodiment described above may be performed in various different modes (modifications) other than that in each embodiment described above. For example, the configuration of the system is not limited to the above-described example, and may be implemented in various modes.

[0278] For example, in the above-described communication system, the management device 10 is disposed at each node of the APN 40, and the communication device 30 is connected to the APN 40 by being connected to the management device 10, but the communication device 30 may be disposed at a node of the APN 40.

[0279] In this case, the communication device 30 is disposed at the same node as the management device 10. The management device 10 and the communication device 30 may constitute a network node as one device (or system). Alternatively, the management device 10 and the communication device 30 may constitute one network node as separate devices.

[0280] In the above-described communication system, the APN 40 is a mesh network. That is, in the APN 40 according to the embodiment of the present disclosure, there are a plurality of paths between a transmission node (source node) and a reception node (destination node). That is, the transmission device 30T selects one from the plurality of paths and performs data transmission.

[0281] However, from the viewpoint of acquiring the dynamic characteristic of a communication path, the number of communication paths according to the present embodiment does not have to be plural. That is, the APN 40 does not need to be a mesh network, and there may be one communication path between a transmission node and a reception node.

[0282] As described above, even in a case where there is one communication path, the communication device 30 acquires the dynamic characteristic of the communication path via the API, whereby the communication device 30 can perform data transmission according to the dynamic characteristic of the communication path.

[0283] For example, a control device that controls the management device 10 or the communication device 30 of the present embodiment may be implemented by a dedicated computer system or may be implemented by a general-purpose computer system.

[0284] For example, a communication program for performing the above-described operations is stored in a computer-readable recording medium such as an optical disk, a semiconductor memory, a magnetic tape, or a flexible disk, and distributed. Then, for example, the control device is implemented by installing the program in a computer and performing the above-described processing. At this time, the control device may be a device (for example, a personal computer) outside the management device 10 or the communication device 30. Furthermore, the control device may be a device (for example, the control unit 130 or the control unit 330) inside the management device 10 or the communication device 30.

[0285] Further, the above-described communication program may be stored in a disk device included in a server device on a network such as the Internet, and be downloaded to a computer. Further, the functions described above may be implemented by cooperation between an operating system (OS) and application software. In this case, the part other than the OS may be stored in a medium and distributed, or the part other than the OS may be stored in a server device and downloaded to a computer.

[0286] Further, among the respective processing described in the above-described embodiments, all or some of the processing described as being automatically performed can be manually performed. Alternatively, all or some of the processing described as being manually performed can be automatically performed by a known method. In addition, the processing procedures, specific names, information including various data and parameters illustrated in the specification and drawings described above can be arbitrarily changed unless otherwise specified. For example, various pieces of information illustrated in the drawings are not limited to those illustrated in the drawings.

[0287] Further, each illustrated component of each device is functionally conceptual, and does not necessarily have to be configured physically as illustrated in the drawings. That is, the specific modes of distribution / integration of the respective devices are not limited to those illustrated in the drawings. All or some of the devices can be functionally or physically distributed / integrated in any arbitrary unit, depending on various loads or the usage status. Note that this configuration by distribution and integration may be dynamically made.

[0288] Further, the above-described embodiments can be appropriately combined as long as the processing contents do not contradict each other. Further, the order of the steps illustrated in the sequence diagram and the like of the above-described embodiments can be changed as appropriate.

[0289] Furthermore, for example, the present embodiment can be implemented as any component included in the device or system, for example, a processor as a system large scale integration (LSI) or the like, a module using a plurality of processors or the like, a unit using a plurality of modules or the like, a set obtained by further adding other functions to a unit, or the like (that is, some components of the device).

[0290] Note that, in the present embodiment, the system means a set of a plurality of components (devices, modules (parts), and the like), and it does not matter whether or not all the components are in the same housing. Therefore, a plurality of devices housed in separate housings and connected via a network and one device in which a plurality of modules are housed in one housing are both systems.

[0291] Furthermore, for example, the present embodiment can adopt a configuration of cloud computing in which one function is shared and processed by a plurality of devices in cooperation via a network.

[0292] <<6. Conclusion>> Although the respective embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure. Moreover, components of different embodiments and modified examples may be appropriately combined.

[0293] Further, the effects in each embodiment described in the present specification are merely examples. The effects of the present disclosure are not limited thereto, and other effects may be obtained.

[0294] Note that the present technology can also have the following configurations. (1) A communication device that communicates with another communication device via an optical network, the communication device comprising: 　a control unit configured to request a management device disposed at a node of the optical network and managing a dynamic characteristic of a transmission path of the optical network to transmit dynamic characteristic information regarding the dynamic characteristic of a communication path with the another communication device by using an application programming interface (API), and configured to acquire the dynamic characteristic information from the management device. 　(2) 　The communication device according to (1), wherein the control unit acquires, as the dynamic characteristic information, information regarding at least one of a delay characteristic or a jitter characteristic of the communication path. 　(3) 　The communication device according to (1) or (2), wherein the control unit acquires, as the dynamic characteristic information, information regarding the communication path that satisfies a predetermined dynamic characteristic. 　(4) 　The communication device according to (3), wherein the control unit acquires, as the dynamic characteristic information, information regarding the communication path that satisfies a predetermined delay time. 　(5) 　The communication device according to (3) or (4), wherein the control unit acquires, as the dynamic characteristic information, information regarding the communication path that satisfies a predetermined jitter amount. 　(6) 　The communication device according to any one of (1) to (5), wherein the control unit acquires, as the dynamic characteristic information, information regarding the communication path that satisfies a predetermined condition. 　(7) 　The communication device according to (6), wherein the control unit acquires, as the dynamic characteristic information, information regarding the communication path that satisfies a predetermined communication cost. 　(8) 　The communication device according to (6) or (7), wherein the control unit acquires, as the dynamic characteristic information, information regarding the communication path that satisfies predetermined power consumption. 　(9) 　The communication device according to any one of (1) to (8), wherein the control unit acquires a notification from the management device. 　(10) 　The communication device according to (9), wherein the management device transmits the notification to the communication device in a case where there is a change in the dynamic characteristic information. 　(11) 　The communication device according to (9) or (10), wherein the management device transmits the notification to the communication device in a case where the communication path selected by the communication device is changed. 　(12) 　The communication device according to any one of (1) to (11), wherein the optical network is an all-photonics network (APN). 　(13) 　A management device disposed at a node of an optical network, the management device comprising: 　a control unit configured to receive a transmission request for dynamic characteristic information regarding a dynamic characteristic of a communication path with a first communication device via an API from a second communication device that communicates with the first communication device via the optical network, configured to acquire the dynamic characteristic of the communication path, and configured to transmit the dynamic characteristic information to the second communication device based on the acquired dynamic characteristic. 　(14) 　The management device according to (13), wherein the control unit acquires the dynamic characteristic from a database that stores the dynamic characteristic. 　(15) 　The management device according to (14), wherein the database stores the dynamic characteristic for each of a plurality of paths of the optical network. 　(16) 　A communication method of a communication device that communicates with another communication device via an optical network, the communication method comprising: 　requesting a management device disposed at a node of the optical network and managing a dynamic characteristic of a transmission path of the optical network to transmit dynamic characteristic information regarding the dynamic characteristic of a communication path with the another communication device by using an API; and 　acquiring the dynamic characteristic information from the management device. 　(17) 　A communication method of a management device disposed at a node of an optical network, the communication method comprising: 　receiving a transmission request for dynamic characteristic information regarding a dynamic characteristic of a communication path with a first communication device via an API from a second communication device that communicates with the first communication device via the optical network; 　acquiring the dynamic characteristic of the communication path; and 　transmitting the dynamic characteristic information to the second communication device based on the acquired dynamic characteristic.

[0295] 10 Management device 30 Communication device 110, 310 Communication unit 120, 320 Storage unit 121 Characteristic information database 130, 330 Control unit 131 Request acquisition unit 132 Characteristic acquisition unit 133 Generation unit 134 Notification unit 331 Information acquisition unit 332 Path selection unit 333 Communication control unit

Claims

1. A communication device configured to communicate with another communication device via an all-photonics network (APN), the communication device comprising: 　circuitry configured to 　obtain characteristic information for each of a plurality of paths in the APN between the communication device and the another communication device, 　select one path of the plurality of paths based on the characteristic information and based on data to be transmitted to the another communication device, and 　transmit the data via the one path selected.

2. The communication device according to claim 1, wherein the communication device connects to the APN via a management device, and the circuitry is further configured to obtain the characteristic information from the management device.

3. The communication device according to claim 1, wherein the characteristic information includes at least one of a delay, a jitter, and a cost for each of the plurality of paths.

4. The communication device according to claim 3, wherein the characteristic information further include delay variation, jitter variation, and dispersion amount.

5. The communication device according to claim 1, wherein the characteristic information is updated periodically.

6. The communication device according to claim 1, wherein the characteristic information is updated in a case that the APN changes.

7. The communication device according to claim 1, wherein the characteristic information is updated in real time.

8. The communication device according to claim 1, wherein criteria used by the circuitry to select the one path is based on a type of the data to be transmitted to the another communication device.

9. The communication device according to claim 8, wherein, in a case that the type of the data includes video data, the circuitry is configured to use minimization of at least one of delay or jitter as the criteria used select the one path.

10. The communication device according to claim 9, wherein the video data is for real-time video playback.

11. The communication device according to claim 10, wherein the real-time video playback includes a live music event or live sporting event.

12. The communication device according to claim 8, wherein, in a case that the type of the data includes clock data, the circuitry is configured to use minimization of at least one of delay or jitter as the criteria to select the one path.

13. The communication device according to claim 8, wherein, in a case that the type of the data does not include time-sensitive data, the circuitry is configured to use cost minimization as the criteria to select the one path.

14. The communication device according to claim 1, wherein the circuitry executes an application to obtain the characteristic information, select the one path, and transmit the data through the one path selected.

15. The communication device according to claim 14, wherein the application obtains the characteristic information, selects the one path, and transmits the data through the one path selected via an application program interface (API).

16. The communication device according to claim 1, wherein in a case that the communication device includes a low-power power source, the circuitry is configured to select the one path as a path that requires a lowest power consumption.

17. The communication device according to claim 1, wherein the plurality of paths of the APN are arranged as a mesh.

18. A management device that manages communication in an all-photonics network (APN), comprising: 　circuitry configured to 　measure at least one characteristic of each of a plurality of paths in the APN to obtain characteristic information of the plurality of paths, 　store the characteristic information, 　in response to a request from a communication device, provide the characteristic information to the communication device, and 　update the characteristic information at least one of periodically or upon a change in the APN.

19. A method for a communication device configured to communicate with another communication device via an all-photonics network (APN), the method comprising: 　obtaining characteristic information for each of a plurality of paths in the APN between the communication device and the another communication device, 　selecting one path of the plurality of paths based on the characteristic information and based on data to be transmitted to the another communication device, and 　transmitting the data via the one path selected.

20. A non-transitory computer-readable medium encoded with computer-readable instructions that, when executed by processing circuitry, cause the processing circuitry to perform the method of Claim 19.

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