Communication device, management device, and communication method

Abstract

To provide a communication device, a management device, and a communication method that are capable of realizing data communication that utilizes the characteristics of an optical network.SOLUTION: 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 uses an API (Application Programming Interface) to request a management device, which is disposed at a node of the optical network and manages dynamic characteristics of a transmission path of the optical network, to transmit dynamic characteristic information regarding the dynamic characteristics of a communication path between the communication device and the other communication device. The control unit acquires the dynamic characteristic information from the management device.SELECTED DRAWING: Figure 18

Description

[Technical field]

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

[0002] One type of optical network known as the All-Photonics Network (APN) is a communications network that is entirely based on light (photonics). In an APN, optical signals are transmitted and optical-electrical conversion is not performed. In other words, in an APN, optical signals are transmitted without being converted to electrical signals. For this reason, in an APN, the processing propagation delay is generally short and the delay variation is also small. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO 2022 / 44137 [Patent Document 2] Special Publication No. 2012-532494 Summary of the Invention [Problem to be solved by the invention]

[0004] As APNs become more widespread in the future, it is expected that APNs will be built to cover wide areas, such as the whole of Japan. When an APN is built, it is expected that the APN will be built in a mesh pattern, for example, so that multiple communication routes can be used to ensure communication availability even if an accident or failure occurs.

[0005] In a mesh network, there are multiple paths from one node to another. The dynamic characteristics of the paths, such as delay time, are different for each path. Even in an APN, the delay time and delay variation are small, but they are not completely zero.

[0006] There is a demand to provide applications and services that utilize the characteristics of such optical networks (e.g., APN) for data communications.

[0007] Therefore, the present disclosure provides a communication device, a management device, and a communication method that can realize data communication that makes use of the characteristics of an optical network.

[0008] It should be noted that the above problem or objective is merely one of several problems or objectives that can be solved or achieved by several embodiments disclosed in this specification. [Means for solving the problem]

[0009] A communication device according to the present disclosure communicates with another communication device via an optical network. The communication device includes a control unit. The control unit uses an API (Application Programming Interface) to request a management device, which is disposed at a node of the optical network and manages dynamic characteristics of a transmission path of the optical network, to transmit dynamic characteristic information regarding the dynamic characteristics of a communication path between the communication device and the other communication device. The control unit acquires the dynamic characteristic information from the management device. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a communication system according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating an example of an APN 40 according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a block diagram illustrating a configuration example of a management device according to an embodiment of the present disclosure. [Figure 4] 11 is a table showing an example of characteristic information according to the embodiment; [Diagram 5] FIG. 1 is a diagram for explaining an example of dispersion according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a diagram illustrating an example of signal transmission according to an embodiment of the present disclosure. [Figure 7]FIG. 13 illustrates an example of buffering by a receiver according to an embodiment of the present disclosure. [Figure 8] FIG. 11 is a diagram illustrating another example of signal transmission according to an embodiment of the present disclosure. [Figure 9] FIG. 13 illustrates an example of buffering by a receiver according to an embodiment of the present disclosure. [Figure 10] 13 is a table showing another example of characteristic information according to the embodiment. [Figure 11] 1 is a block diagram illustrating a configuration example of a communication device according to an embodiment of the present disclosure. [Figure 12] FIG. 2 is a diagram for explaining an example of an API according to an embodiment of the present disclosure. [Figure 13] FIG. 13 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. [Figure 14] FIG. 13 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. [Figure 15] FIG. 13 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. [Figure 16] FIG. 13 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. [Figure 17] FIG. 13 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. [Figure 18] FIG. 11 is a diagram for explaining an example of a communication process according to an embodiment of the present disclosure. [Figure 19] 11 is a flowchart illustrating an example of a flow of an automatic route selection process according to an embodiment of the present disclosure. [Figure 20] 11 is a flowchart illustrating an example of a flow of a route setting process according to an embodiment of the present disclosure. [Figure 21] 11 is a flowchart illustrating an example of a flow of an event process according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted.

[0012] In addition, in this specification and drawings, similar components of the embodiments may be distinguished by adding at least one of different alphabets and numbers after the same reference numeral. However, when there is no need to particularly distinguish between similar components, only the same reference numerals are used. For example, multiple components having substantially the same functional configurations are distinguished as necessary, such as a first communication device 30_1 and a second communication device 30_2. For example, when there is no need to particularly distinguish between the first communication device 30_1 and the second communication device 30_2, they are simply referred to as communication device 30.

[0013] One or more embodiments (including examples, modifications, and application examples) described below can be implemented independently. Meanwhile, at least a part of the embodiments described below may be implemented in appropriate combination with at least a part of another embodiment. These embodiments may include novel features different from each other. Thus, these embodiments may contribute to solving different purposes or problems and may provide different effects.

[0014] <<1. Introduction>> Development of the All-Photonics Network (APN) is underway as the next-generation optical network. In an APN, essentially only optical signals are transmitted between nodes. Therefore, in an APN, optical signals are processed without being converted to electrical signals. In other words, in an APN, after optical signals are converted to electrical signals, buffering or information processing by electronic circuits is not generally performed.

[0015] Therefore, APNs generally have the characteristics of short processing propagation delay and small delay variation.

[0016] As described above, when an APN is constructed to cover a wide area, the APN is thought to be constructed in a mesh pattern in order to ensure communication availability even in the event of an accident or failure.

[0017] In such a mesh-type APN, there are multiple paths between two nodes. The transmission delay time in multiple paths is basically determined by the length of the path between the two nodes. More specifically, it is determined by the time it takes for laser light to propagate through the optical fiber between the two nodes.

[0018] Generally, all-photonics networks have short propagation delay times and small delay variations (jitter), but these are not completely zero. The propagation delay times and jitter amounts differ for each of the multiple paths.

[0019] Compared to conventional best-effort networks (e.g., the Internet), APNs have shorter transmission delays and smaller delay variations. However, in a mesh-structured APN, the propagation delay varies depending on the route selected at any given time among multiple routes.

[0020] In this way, even if an APN has a short propagation delay and small delay variation, the characteristics of the route (transmission path) differ for each selected route in reality. Therefore, it is difficult to perform transmission based on an ideal transmission path with zero delay and / or delay variation.

[0021] From the perspective of applications that use APNs to provide services to users, APNs have performance advantages over conventional best-effort networks, such as low latency and low jitter.

[0022] On the other hand, in reality, even with an APN, delay and jitter are not zero, and they are not fixed values, so it is difficult for applications to provide services that assume zero delay and jitter.

[0023] If the network architecture of the APN is constructed on the assumption that the delay and jitter are not zero, it may end up being similar to the architecture of a conventional best-effort network. In other words, by buffering signals at the transmission and reception of the APN, the same processing as that of the conventional best-effort network, such as absorbing delay variations and smoothing rate variations, may be performed.

[0024] As such, a network architecture similar to that of a conventional best-effort network may not be able to realize applications that fully utilize the characteristics of an APN. In other words, if the characteristics of the APN's communication path (transmission path) are not determined, the APN will only achieve some degree of difference in speed, low latency, and low jitter compared to a conventional best-effort network.

[0025] In this case, it cannot be said that the application can provide the user with a service that fully utilizes the features of the APN that is not of the best effort type.

[0026] Furthermore, when there are multiple transmission paths between the sender and receiver, the propagation delay time differs for each path. Also, the equipment and geographical environment of the transmission paths differ. Examples of geographical environments include physical distance, temperature, altitude, air pressure, and vibration. Due to such differences, the amount of jitter may differ for each path. Also, due to differences in equipment, power consumption may differ for each path.

[0027] In such a situation, if the transmitting side sends out data without considering the propagation delay, depending on the selected route, the receiving side's buffer may collapse, causing interruptions in the data (such as video data).

[0028] The general solution to this problem is to provide a large receive buffer on the receiving side. The amount of data stored in this receive buffer absorbs the data rate fluctuations and delay fluctuations caused by the transmission path. However, inserting a receive buffer has the problem of increasing delays.

[0029] The communication device according to this embodiment is a communication device that communicates with other communication devices via an optical network (e.g., APN). The communication device includes a control unit. The control unit requests the management device to transmit dynamic characteristic information regarding the dynamic characteristics of the communication path between the communication device and the other communication device using an API (Application Programming Interface). The management device is disposed at a node of the optical network and manages the dynamic characteristics of the transmission path of the optical network. The control unit acquires the dynamic characteristic information from the management device.

[0030] In this manner, in the optical network (e.g., APN) of this embodiment, an API is defined that enables applications and services (more specifically, communication devices that execute applications or provide services) to grasp the characteristics (e.g., dynamic characteristics) of the optical network.

[0031] By using the API, the communication device can know the status (e.g., dynamic characteristics) of the optical network. This enables the communication device to execute applications and provide services that are premised on a network with low latency and / or low jitter. Examples of dynamic characteristics include latency and jitter.

[0032] In an APN, delay and jitter are mostly determined by the static characteristics of the communication path. Furthermore, the fluctuation range of delay and jitter is basically small. Therefore, the management device can estimate (estimate) the dynamic characteristics of the APN (e.g., the amount of delay and jitter) with high accuracy.

[0033] By making use of this characteristic, a communication device that executes an application (hereinafter, also simply referred to as an application) can proactively select an optimal route according to, for example, the characteristics of data to be transmitted or received.

[0034] It is believed that the application knows best the characteristics of the data being sent and received. By selecting the optimal route, the application can take advantage of the APN characteristics and provide users with services that are appropriate for the characteristics of the data being sent and received.

[0035] To achieve this, the APN transmission framework according to this embodiment provides an API to an upper layer application. The application can obtain information about the characteristics of the APN (e.g., dynamic characteristic information) through the API, and can determine the optimal transmission method according to the service to be provided (e.g., the purpose of the data to be transmitted and received, etc.).

[0036] When the delay time and fluctuation range of a data packet are known in advance, for example, the delay time is almost constant and the fluctuation range is small, the communication system including the APN can reduce the margin of the transmission and / or reception buffer size for absorbing the delay fluctuation and rate fluctuation. The communication system can further reduce the delay time caused by temporarily storing the signal in the buffer.

[0037] Furthermore, if the amount of jitter of a data packet passing through an APN is known in advance, such as the amount of jitter being equal to or less than a predetermined value, the communication system can guarantee the accuracy of a phase locked loop (PLL) through the network.

[0038] Conventionally, clock synchronization systems have been able to achieve synchronization with the desired degree of accuracy in short-distance local environments, but it has been difficult to achieve accurate synchronization across an entire network.

[0039] As described above, the communication system according to the present embodiment can provide the amount of jitter for the APN, which enables the clock synchronization system to achieve synchronization with a desired accuracy across the entire APN.

[0040] Therefore, for example, an application can display video at a remote location using a synchronization signal generated from a high-precision clock on the sending side, allowing video to be displayed at the remote location without any loss of synchronization.

[0041] On the other hand, depending on the data being transmitted and received, there may be data that does not need to be transmitted in real time with low latency and low jitter. When transmitting such data that does not require real-time transmission, the application selects a communication path with lower network usage costs than low latency and low jitter characteristics. This allows the application to transfer data at a lower cost.

[0042] For example, there may be cases where the amount of power available for data transmission is limited, such as when data transmission is performed using green power from wind power generation, solar power generation, or when the battery is not fully charged. In such cases, the application may preferentially select a communication path with low power consumption to transmit data.

[0043] In this embodiment, an API is defined that allows an application to obtain information about dynamic characteristics of an APN, such as delay time, amount of jitter, communication cost, power consumption, etc., so that the application can select a communication path according to the data to be transmitted. This allows the application to perform data communication taking advantage of the characteristics of the APN.

[0044] The dynamic characteristic information regarding the dynamic characteristic may include information regarding a communication path according to a desired dynamic characteristic. For example, an application notifies a management device of a desired dynamic characteristic (e.g., a desired amount of delay, etc.) via an API. The management device notifies the application of information regarding a communication path according to the dynamic characteristic of the APN.

[0045] The application selects a communication path to use for data transmission from the communication paths notified by the management device. In this way, the application may specify conditions for dynamic characteristics, and the management device may notify the application of a communication path according to the conditions. In this case, too, the application can perform data communication that makes use of the characteristics of the APN.

[0046] In this way, the communication system according to the present embodiment defines an API so that the communication device 30 can select a route according to a use case. This allows the communication device 30 to know detailed information about the network and to select a route according to the detailed information about the network.

[0047] In conventional best-effort networks, it was not possible to manage (control) detailed dynamic characteristics. Or, it was difficult to perform precise route selection based on detailed operating characteristics. This is because the fluctuation range of the dynamic characteristics of conventional best-effort networks is very large. Thus, in conventional best-effort networks, even if precise route selection was performed based on detailed dynamic characteristics, the dynamic characteristics of the selected route would fluctuate, and there was a high possibility that the desired route characteristics would not be satisfied.

[0048] Therefore, in conventional best-effort networks, there was little need to acquire detailed dynamic characteristics to select precise routes. This is why it is called "best-effort," and in conventional networks there was little need for APIs to acquire information about detailed dynamic characteristics. On the other hand, APNs can now manage detailed dynamic characteristics, so applications are now required to select routes according to differences in route characteristics.

[0049] Therefore, in the communication system according to the present embodiment, the route selection that was previously performed in the lower layer of the network hierarchical model can be performed by the application in the upper layer by using the API, which makes it possible to select a communication route that satisfies the dynamic characteristics desired by the application.

[0050] In APN, delay and jitter are sufficiently small, and further reduction is a matter of degree. Therefore, in this embodiment, we focus on the issue of selecting the optimal route from multiple routes that remain even when the network has low delay and low jitter. The technology according to this embodiment allows the selection to be made by the application that is most familiar with the purpose of using the network and the characteristics of the transmitted and received data.

[0051] In this embodiment, a use case is assumed in which an application provides users with services such as large-scale real-time video and audio distribution of live music, sports, etc. However, the services provided by the application are not limited to these distributions. The technology of this embodiment can be applied to applications that provide various services, but is particularly useful for transmitting video and audio data.

[0052] <<2. Example of communication system configuration>> <2-1. Example of overall configuration of communication system> 1 is a diagram illustrating an example of an overall configuration of a communication system according to an 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, a first communication device 30_1, a second communication device 30_2, and an APN 40.

[0053] The management device 10 is a device that manages the characteristics of the APN 40. For example, the management device 10 is disposed in each node of the APN 40, as described later.

[0054] The management device 10, for example, measures and / or estimates dynamic characteristics of the APN 40 and stores the results in a characteristic information database. In addition, the management device 10, for example, obtains information (for example, dynamic characteristics) from the characteristic information database.

[0055] The characteristic information database holds, for example, the dynamic characteristics described above as well as static characteristics of the APN 40. The static characteristics include information on characteristics that do not change dynamically, such as the start point and end point of a communication path and the physical distance of a communication path.

[0056] The static characteristics may be stored in the characteristics information database in response to a notification from the management device 10, or may be stored by an administrator of the APN 40. Alternatively, the static characteristics may be stored in the characteristics information database when the APN 40 is constructed or updated.

[0057] The characteristic information database stores, for example, static characteristics and dynamic characteristics in association with each other.

[0058] The management device 10 generates dynamic characteristic information related to dynamic characteristics in response 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 related to characteristics that change dynamically in the communication path of the APN 40. The dynamic characteristic includes, for example, information related to the delay time (amount of delay) and amount of jitter in the communication path. Details of the dynamic characteristic will be described later.

[0059] The dynamic characteristic information may be information including the dynamic characteristic itself, or may be information generated according to the dynamic characteristic (for example, route information regarding a communication route). The dynamic characteristic information will be described in detail later.

[0060] The first communication device 30_1 and the second communication device 30_2 are communication devices that transmit and / or receive data to and from each other. 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.

[0061] Hereinafter, a communication device 30 that transmits data may be distinguished as a transmitting device 30T, and a communication device 30 that receives data may be distinguished as a receiving device 30R.

[0062] 1, the communication system has two management devices 10 (first management device 10_1, second management device 10_2) and communication devices 30 (first communication device 30_1, second communication device 30_2), but the number of management devices 10 and communication devices 30 is not limited to two. The communication system may have three or more management devices 10 and three or more communication devices 30.

[0063] 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.

[0064] Note that optical communication may be performed between the management device 10 and the communication device 30, or communication other than optical communication may be performed.

[0065] The details of APN 40 are explained below.

[0066] As described above, APN40 is a network that transmits optical signals, not electrical signals. In APN40, optical-electrical signal conversion, buffering by electronic circuits, and information processing are not performed. Therefore, in APN40, delay time is generally short and delay variation is small. APN40 is not a best-effort type network as typified by the conventional Internet, but is a network that can guarantee actual communication speed to a certain degree.

[0067] The APN 40 can provide a plurality of communication paths between the first communication device 30_1 and the second communication device 30_2. The APN 40 is, for example, a mesh optical network.

[0068] Fig. 2 is a diagram illustrating an example of an APN 40 according to an embodiment of the present disclosure. The APN 40 illustrated in Fig. 2 includes nodes A to J. For example, the above-mentioned management device 10 may be disposed in the nodes.

[0069] Each of the nodes A to J is connected to at least one other node via a transmission line. 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.

[0070] Each node A to J of the APN 40 is connected to one another by at least one route. The APN 40 is a mesh network. By making the APN 40 a mesh network, it is possible to ensure route redundancy, secure land on which communication lines can be laid, ensure a stable supply of power, and respond to increased traffic.

[0071] In the APN 40 according to this embodiment, there are paths that have a larger amount of jitter than other paths. In the example of Fig. 2, the path between nodes A and C (hereinafter also referred to as path AC), the path between nodes E and J (hereinafter also referred to as path EJ), and the path between nodes F and J (hereinafter also referred to as path FJ) have a larger amount of jitter than other paths.

[0072] In the APN 40 according to the present embodiment, there are routes that have larger delay variations than other routes. In the example of Fig. 2, the route between nodes B and F (hereinafter also referred to as route BF), the route between nodes F and G (hereinafter also referred to as route FG), and the route between nodes I and J (hereinafter also referred to as route IJ) have larger delay variations than other routes.

[0073] Note that the number of nodes, connections, and paths in which jitter and delay variation are large are merely examples. For example, the number of nodes included in the APN 40 according to this embodiment may be 9 or less, or 11 or more.

[0074] <2-2. Example of management device configuration> The management device 10 is, for example, a device disposed at a node of the APN 40. The management device 10 may be, for example, a device that relays a connection between the communication device 30 and the APN 40.

[0075] 3 is a block diagram showing an example of a configuration of the management device 10 according to an embodiment of the present disclosure. The management device 10 includes a communication unit 110, a storage unit 120, and a control unit .

[0076] 3 is a functional configuration, and the hardware configuration may be different from this. The functions of the management device 10 may be statically or dynamically distributed and implemented in multiple physically separated configurations. For example, the management device 10 may be composed of multiple server devices.

[0077] (Communication unit 110) The communication unit 110 is a communication interface for communicating with other communication devices (for example, other management devices 10, communication devices 30, etc.) via the APN 40. The communication unit 110 may be a network interface or a device connection interface.

[0078] For example, the communication unit 110 according to this embodiment performs communication using optical signals, that is, the communication unit 110 has a circuit for transmitting and receiving optical signals.

[0079] 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 that connects to a network other than the APN 40. For example, the communication unit 110 may be a LAN (Local Area Network) interface such as a NIC (Network Interface Card), or a USB interface configured by a USB host controller, a USB port, etc.

[0080] The communication unit 110 may be a wired interface or a wireless interface. The communication unit 110 functions as a communication means of the management device 10. The communication unit 110 communicates with other communication devices under the control of the control unit 130.

[0081] (Storage unit 120) The storage unit 120 is a data readable / writable storage device such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, a hard disk, etc. The storage unit 120 has a characteristic information database 121 that stores characteristic information including, for example, static characteristics and dynamic characteristics of the APN 40. The storage unit 120 functions as a storage unit of the management device 10.

[0082] Fig. 4 is a table showing an example of characteristic information according to this embodiment. The characteristic information shown in Fig. 4 includes static information indicating static characteristics of the APN 40 and dynamic information indicating dynamic characteristics of the APN 40. The static information is constant information that does not change over time. The dynamic information is information that may change over time.

[0083] 4 includes, for example, information indicating the start point and end point of a route, the distance between the two points, and a propagation delay time determined only by the distance. The start point and end point of a route are, for example, information specifying two adjacent nodes among the nodes A to J of the APN 40.

[0084] The distance between two points is information that indicates the physical distance between a start point and an end point. In the example of Fig. 4, the distance between two points where the start point is node A and the end point is node B is "200". Also, the distance between two points where the start point is node A and the end point is node B is "300".

[0085] A propagation delay time determined only by distance is a delay time determined by the distance between two points. A propagation delay time determined only by distance is a delay time that does not change with time. The propagation delay time determined only by the distance between two points, where the start point is node A and the end point is node B, is "20". Also, the propagation delay time determined only by the distance between two points, where the start point is node A and the end point is node B, is "30".

[0086] The dynamic information includes, for example, delay increase due to the path environment, effective delay time, dispersion, cost, and power consumption.

[0087] The delay increase due to the route environment is information that indicates the amount of delay that increases due to the environment of the route between the start point and the end point. The route environment is the environment in which the optical fiber connecting the start point and the end point is placed. Examples of the route environment include air temperature, altitude, air pressure, and vibration. The delay increase due to the route environment represents the delay fluctuation caused by the route environment.

[0088] For example, temperature varies throughout the day. The delay increase due to the route environment (route delay time) may vary according to the temperature. Thus, the delay increase due to the route environment is a parameter that may vary with time.

[0089] The delay increase due to the route environment between two points, the start point of which is node A and the end point of which is node B, is "1." Also, the delay increase due to the route environment between two points, the start point of which is node A and the end point of which is node C, is "5."

[0090] The effective delay time is information indicating the actual delay time between the start point and the end point. The effective delay time is, for example, the sum of the propagation delay time determined only by the distance and the delay increase due to the route environment.

[0091] The effective delay time between two points, whose starting point is node A and whose ending point is node B, is "21" (20+1). Also, the effective delay time between two points, whose starting point is node A and whose ending point is node C, is "35" (30+5).

[0092] The variance is information (parameter) that indicates how large the variation in delay time between a start point and an end point is, for example, and includes jitter variation and environmental factors.

[0093] Fig. 5 is a diagram for explaining an example of dispersion according to an embodiment of the present disclosure. Fig. 5 is a schematic diagram showing the relationship between the delay time (theoretical value) determined only by the distance and the actual delay time taking into account the delay factors caused by the route environment and the system delay factors caused by the equipment used.

[0094] As shown in Figure 5, the effective delay time is the delay time determined only by the distance (the propagation delay time between nodes determined only by the distance) plus the delay increase (the delay increase due to the route environment). The actual delay time is the effective delay time plus jitter. Dispersion is a parameter that indicates how large this jitter (delay variation) is.

[0095] A route with large dispersion has a large fluctuation range of delay, or in a broader sense, it can be said to be a route with a lot of jitter. Alternatively, there may be a route with small jitter even if the delay increase due to the route environment is large. For example, in an ideal transmission route with no jitter, the transmission delay time is a fixed value.

[0096] In order to absorb the jitter, the receiving side (for example, the receiving device 30R) uses a buffer. Here, the relationship between the jitter and the receiving side buffer will be explained with reference to Figs.

[0097] Fig. 6 is a diagram illustrating an example of signal transmission according to an embodiment of the present disclosure, in which an example of signal transmission is shown in an ideal transmission path with no jitter.

[0098] 6, a signal transmitted from a transmitting side (e.g., transmitting device 30T) arrives at a receiving side (e.g., receiving device 30R) with a delay of a delay time Δ. As described above, in an ideal transmission path, no jitter occurs, so the delay time Δ is constant.

[0099] Fig. 7 is a diagram illustrating an example of buffering by the receiving side according to an embodiment of the present disclosure. Fig. 7 illustrates an example of buffering by the receiving side when the signal transmission illustrated in Fig. 6 is performed.

[0100] As mentioned above, in an ideal transmission path, jitter does not occur, and the propagation time of a signal from the sender to the receiver is a constant value (propagation time Δ) that is the same as the delay time. In this way, if the amount of delay (delay time Δ) is constant and does not fluctuate, the receiver does not need to smooth the signal arrival time by buffering.

[0101] For example, if the data transmitted from the transmitting side is image data and the receiving side displays the image data on a display, if the delay time Δ is constant and does not vary, the receiving side can display the image data on the display with a delay of the delay time Δ without buffering, and can maintain the continuity of the image display.

[0102] In this way, in an ideal transmission path without jitter, the transmission delay time is a fixed value, and therefore buffering to absorb jitter on the receiving side is not required.

[0103] Fig. 8 is a diagram showing another example of signal transmission according to an embodiment of the present disclosure, in which an example of signal transmission in a transmission path in which jitter occurs is shown.

[0104] As shown in Fig. 8, a signal transmitted from a transmitting side (e.g., transmitting device 30T) arrives at a receiving side (e.g., receiving device 30R) with a delay. In the example of Fig. 8, jitter occurs, so the amount of delay varies with time. The amount of delay varies within a range of ±α, for example.

[0105] Fig. 9 is a diagram illustrating an example of buffering by the receiving side according to an embodiment of the present disclosure. Fig. 9 illustrates an example of buffering by the receiving side when the signal transmission illustrated in Fig. 8 is performed.

[0106] As mentioned above, jitter occurs in an actual transmission line, so the propagation time of a signal from the sending side to the receiving side fluctuates within a range of ±α (propagation time Δ±α).

[0107] In this way, when jitter occurs, the receiving side smooths the signal arrival time by buffering. The receiving side temporarily stores packets to ensure a continuous supply of data so that the buffer does not overflow or underflow even if the packet (signal) arrival time fluctuates by α hours.

[0108] At this time, the time that the signal is stored in the buffer on the receiving side (buffer residence time β) is much larger than the fluctuation amount α of the delay amount (β>>α).

[0109] For example, if the data transmitted from the transmitting side is image data and the receiving side displays the image data on a display, when the delay time Δ varies within the range of ±α, the receiving side needs to buffer the received signal for a buffer residence time β, and the image data is displayed on the display with a delay of Δ+β.

[0110] This allows the receiving side to maintain continuity of image display even if jitter occurs.

[0111] As described above, because jitter exists in real transmission paths, the arrival time of packets fluctuates at the receiving side. To smooth out this fluctuation, buffering is required at the receiving side.

[0112] If the delay variation (α) occurs at a high frequency, the receiver can absorb the jitter with a small buffer capacity. On the other hand, if the delay variation (α) occurs at a low frequency, the receiver needs to use a large buffer capacity to absorb the jitter.

[0113] Therefore, when the delay variation (α) occurs at a low frequency, the delay (β) caused by buffering on the receiving side becomes large. In this way, in addition to the variance of the delay variation, the frequency distribution may be considered as a more detailed characteristic of the delay variation. In other words, the frequency distribution of the delay variation may be included as dynamic information.

[0114] Returning to Fig. 4, the variance indicates, for example, the range α of the delay time fluctuation described above. In the example of Fig. 4, the variance between two points, the start point of which is node A and the end point of which is node B, is "0.1". Also, the variance between two points, the start point of which is node A and the end point of which is node C, is "0.7".

[0115] As described above, the dynamic information includes costs. The costs are, for example, expenses incurred when using a transmission line. Examples of the costs include line usage fees.

[0116] The dynamic information also includes power consumption. Power consumption is, for example, power consumed when transmitting a signal. For example, power consumption is power consumed in processing to transmit a signal. For example, if a signal is significantly attenuated when transmitting through a transmission path, the power consumption is large.

[0117] If the cost and / or power consumption does not fluctuate in the short term (or fluctuates only slightly), they may be included in the static information.

[0118] In this manner, the characteristic information database 121 holds, for example, the characteristics (characteristic information) of a route between two adjacent points shown in FIG.

[0119] 4 shows characteristic information for a case where the outbound and inbound routes of a route between two adjacent points have the same characteristics. When the characteristics of the APN 40 differ between the outbound and inbound routes, the characteristic information database 121 stores characteristic information for each of the outbound and inbound routes.

[0120] The characteristic information is updated periodically or when the status of the APN 40 changes. The characteristic information is updated, for example, in real time. Furthermore, each piece of information (parameters) shown in FIG. 4 is given as an example of a relative value, and the unit is not particularly specified.

[0121] In addition, although the characteristic information includes the characteristics between adjacent nodes here, the characteristic information is not limited to this. For example, the characteristic information database 121 may hold characteristic information including the characteristics of the path between the transmitting node and the receiving node.

[0122] Fig. 10 is a table showing another example of characteristic information according to this embodiment. In Fig. 10, some of the possible routes when the transmitting node is node A and the receiving node is node I are shown as a list. Note that Fig. 10 omits the display of routes that are obviously longer than other routes (for example, routes whose distance is longer than a predetermined value).

[0123] 10 includes static information indicating static characteristics of the APN 40 and dynamic information indicating dynamic characteristics of the APN 40. The static information includes, for example, the route from node A to node I and the route distance. The dynamic information includes the effective delay time (effective delay time) and the variance.

[0124] 10 is a route from node A to node I via nodes C and G. This route includes the route between node A and node C, the route between node C and node G, and the route between node G and node I.

[0125] For example, in APN 40 according to this embodiment, the distance between node A and node C is 300, the distance between node C and node G is 500, and the distance between node G and node I is 200 (see FIG. 4). Therefore, the route distance of "ACGI" is 300+500+200=1000.

[0126] In APN 40 according to this embodiment, the effective delay time between node A and node C is 35, the effective delay time between node C and node G is 53, and the effective delay time between node G and node I is 21 (see FIG. 4). Therefore, the effective delay time of "ACGI" is 35+53+21=109.

[0127] In APN 40 according to this embodiment, the variance between node A and node C is 0.7, the variance between node C and node G is 0.2, and the variance between node G and node I is 0.2 (see FIG. 4). Therefore, the variance of "ACGI" is 0.7+0.2+0.2=1.1.

[0128] In this way, the characteristics of the path between the sending node and the receiving node are found as the sum of the characteristics of the paths connecting each node included in the path.

[0129] In this manner, the characteristic information database 121 may hold the characteristics (characteristic information) of the route between the transmitting and receiving nodes shown in FIG.

[0130] For example, the management device 10 may store in the characteristic information database 121 characteristic information having the node where the management device 10 is located as the origin (transmission node).

[0131] The characteristic information is updated periodically or when the status of the APN 40 changes. The characteristic information is updated, for example, in real time. Furthermore, each piece of information (parameters) shown in FIG. 10 is given as an example of a relative value, and the unit is not particularly specified.

[0132] (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 realized by a processor such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a GPU (Graphics Processing Unit). For example, the control unit 130 is realized by the processor executing various programs stored in a storage device inside the management device 10 using a RAM or the like as a working area. The control unit 130 may be realized by an integrated circuit such as an ASIC or an FPGA. Any of the CPU, MPU, GPU, ASIC, and FPGA can be considered as a controller.

[0133] As shown 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 (request acquisition unit 131 to notification unit 134) constituting 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-mentioned functional blocks may be a software module realized by software (including a microprogram), or may be a circuit block on a semiconductor chip (die). Of course, each of the functional blocks may be a processor or an integrated circuit. The functional blocks may be configured in any manner. The control unit 130 may be configured in a functional unit different from the above-mentioned functional blocks. The internal configuration of the control unit 130 is not limited to the configuration shown in FIG. 3, and may be another configuration as long as it performs the processing described later.

[0134] (Request acquisition unit 131) The request acquisition unit 131 acquires a notification requesting dynamic characteristic information from the communication device 30 via an API defined in the communication system. The request acquisition unit 131 instructs the characteristic acquisition unit 132 to acquire dynamic characteristics in response to the acquired request.

[0135] (Characteristics Acquisition Unit 132) The characteristic acquisition unit 132 acquires information about dynamic characteristics from the characteristic information database 121 in accordance with an instruction from the request acquisition unit 131. The characteristic acquisition unit 132 notifies the generation unit 133 of the acquired dynamic characteristics.

[0136] (Generation unit 133) The generating unit 133 generates dynamic characteristic information based on the dynamic characteristics. For example, the generating unit 133 generates dynamic characteristic information including dynamic characteristics requested by the communication device 30 from among the dynamic characteristics acquired by the characteristic acquiring unit 132.

[0137] Alternatively, the generation unit 133 may generate dynamic characteristic information including a communication path that satisfies a condition specified by the communication device 30.

[0138] The generating unit 133 generates dynamic characteristic information in accordance with a request from the communication device 30. The generating unit 133 outputs the generated dynamic characteristic information to the notifying unit .

[0139] (Notification Department 134) The notification unit 134 notifies the communication device 30 of the dynamic characteristic information generated by the generation unit 133 .

[0140] Furthermore, when an event occurs in the APN 40, the notification unit 134 notifies the communication device 30 of the event. For example, when the dynamic characteristics of a communication path used by the communication device 30 for data transmission change, the notification unit 134 notifies the communication device 30 of the change.

[0141] For example, when a condition specified by the communication device 30 is satisfied, the notification unit 134 notifies the communication device 30 of an event. Examples of the condition specified by the communication device 30 include the type of characteristic (e.g., delay time, amount of jitter, etc.) and a change in characteristic (e.g., delay time has increased, the amount of jitter has exceeded a specified value, etc.).

[0142] In this way, the management device 10 may notify the communication device 30 of dynamic characteristic information via the API in response to a request from the communication device 30, or may notify the communication device 30 of an event triggered by the occurrence of an event such as a change in dynamic characteristics.

[0143] <2-3. Example of communication device configuration> The communication device 30 is an information processing device that communicates with other communication devices 30 via the APN 40. The communication device 30 may be, for example, a mobile phone, a smart device (smartphone or tablet), a PDA (Personal Digital Assistant), a personal computer, a camera, or the like. The communication device 30 may be a head mounted display or VR goggles having a function of wirelessly transmitting and receiving data. The communication device 30 may be any information processing device having a function of executing an application.

[0144] The communication device 30 connects to the APN 40 by connecting to, for example, the management device 10. Alternatively, the communication device 30 may connect to the APN 40 directly or by connecting to a device different from the management device 10. In this case, the communication device 30 accesses the management device 10 to obtain dynamic characteristic information related to the dynamic characteristic of the APN 40.

[0145] 11 is a block diagram showing an example of a configuration of a communication device 30 according to an embodiment of the present disclosure. The communication device 30 includes a communication unit 310, a storage unit 320, and a control unit 330.

[0146] 11 is a functional configuration, and the hardware configuration may be different from this. Also, the functions of the communication device 30 may be statically or dynamically distributed and implemented in multiple physically separated configurations.

[0147] (Communication unit 310) The communication unit 310 is a communication interface for communicating with other communication devices (for example, the management device 10 and other communication devices 30) via the APN 40. The communication unit 310 may be a network interface or a device connection interface.

[0148] For example, the communication unit 310 according to this embodiment may perform communication using optical signals, that is, the communication unit 310 may have a circuit for transmitting and receiving optical signals.

[0149] As described above, when the communication device 30 connects to a network other than the APN 40, the communication unit 310 may be a communication interface that connects to a network other than the APN 40. For example, the communication unit 310 may be a LAN (Local Area Network) interface such as a NIC (Network Interface Card), or a USB interface configured by a USB host controller, a USB port, etc.

[0150] The communication unit 310 may be a wired interface or a wireless interface. The communication unit 310 functions as a communication means of the communication device 30. The communication unit 310 communicates with other communication devices under the control of the control unit 330.

[0151] (Storage unit 320) The storage unit 320 is a data readable / writable storage device such as a DRAM, an SRAM, a flash memory, a hard disk, etc. The storage unit 320 functions as a storage unit of the communication device 30.

[0152] (Control unit 330) The control unit 330 is a controller that controls each unit of the communication device 30. The control unit 330 is realized by a processor such as a CPU, an MPU, or a GPU. For example, the control unit 330 is realized by a processor executing various programs stored in a storage device inside the management device 10 using a RAM or the like as a working area. The control unit 330 may be realized by an integrated circuit such as an ASIC or an FPGA. The CPU, the MPU, the GPU, the ASIC, and the FPGA can all be considered as controllers.

[0153] As shown 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 (information acquisition unit 331 to communication control unit 333) constituting the control unit 330 is a functional block showing a function of the control unit 330. These functional blocks may be software blocks or hardware blocks. For example, each of the above-mentioned functional blocks may be a software module realized by software (including a microprogram), or may be a circuit block on a semiconductor chip (die). Of course, each of the functional blocks may be a processor or an integrated circuit. The functional blocks may be configured in any manner. The control unit 330 may be configured in a functional unit different from the above-mentioned functional blocks. The internal configuration of the control unit 330 is not limited to the configuration shown in FIG. 11, and may be another configuration as long as it performs the processing described later.

[0154] The control unit 330 also functions as an application execution unit. The control unit 330 provides an application service to the user by operating as an application. Each unit of the control unit 330 (information acquisition unit 331 to communication control unit 333) can operate as a function of the application.

[0155] (Information acquisition unit 331) The information acquisition unit 331 requests dynamic characteristic information from the management device 10 via an 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.

[0156] (Route selection unit 332) The route selection unit 332 selects a route for transmitting data based on the dynamic characteristic information. For example, when the dynamic characteristic information includes a delay time (e.g., a real delay time) and a jitter (e.g., a dispersion), the route selection unit 332 selects a route that satisfies the communication quality (e.g., low delay and / or low jitter) required for the data to be transmitted.

[0157] On the other hand, as described below, when the dynamic characteristic information includes information on a route that satisfies a required condition (communication quality), the route selection unit 332 selects, for example, the route included in the dynamic characteristic information as the route to be used for data transmission.

[0158] The route selection unit 332 outputs the selected route to the communication control unit 333.

[0159] (Communication control unit 333) The communication control unit 333 controls the communication unit 310 so as to transmit data via the route selected by the route selection unit 332 .

[0160] <<3.Example of API>> Next, an example of APIs and event notifications defined in the communication system according to the present embodiment will be described. Note that the APIs and events described here are merely examples, and the APIs and events defined in the communication system are not limited to those described here. APIs and events other than the APIs and events described here may be defined in the communication system, or at least one of the APIs and events described here may not be defined in the communication system.

[0161] The API according to this embodiment is a program module that returns a value when a function is called with one or more arguments. The example described here is an implementation example of the API specification, and it is possible to express similar functions using different grammar.

[0162] For example, the true values ​​described below may be represented as a pointer to a memory address where the value is stored, or as a member of an object or class. Furthermore, the types of the variables described below are not particularly limited, and any type may be used.

[0163] <3-1.SetDeliveryPath()> 12 is a diagram for explaining an example of an API according to an embodiment of the present disclosure. This API, SetDeliveryPath(), is an API that specifies a destination node to which data is sent, and at the same time, specifies desired characteristics for the path, and provides an application with a path that satisfies the conditions.

[0164] SetDeliveryPath() has the role of establishing a network path with specified characteristics, that is, the communication device 30 may use this API to establish a network path with desired characteristics.

[0165] SetDeliveryPath() takes, for example, DestinationNode, Mode, and PathID as arguments. DestinationNode is an argument that indicates the node to which data is to be sent. DestinationNode represents an address that can uniquely identify a node on the network. The management device 10 identifies the destination node based on these arguments and establishes a communication path.

[0166] Mode is an argument that specifies dynamic characteristics. For example, a value from 1 to 5 is specified as Mode. "1" specifies a mode that prioritizes reducing delay. When "1" is set as Mode, the management device 10 selects a path for transmitting data to a destination node (a node set in DestinationNode) with priority given to the shortest delay time.

[0167] "2" specifies a mode that prioritizes synchronization stability through PLL stabilization. When "2" is set as the mode, the management device 10 selects a route for transmitting data to the destination node with the minimum packet jitter. In other words, the management device 10 selects a route with the minimum amount of delay jitter.

[0168] "3" specifies a low-cost priority mode. When "3" is set as the mode, the management device 10 selects a route for transmitting data to a destination node under the minimum cost (charging) condition. In other words, the management device 10 selects a route with the minimum cost (charging fee).

[0169] "4" specifies the eco-friendly mode. When "4" is set as the mode, the management device 10 selects a route for transmitting data to the destination node under the condition of minimum power consumption. In other words, the management device 10 selects a route with the minimum power consumption.

[0170] "5" is set when no particular condition for dynamic characteristics is specified. When "5" is set as the Mode, the management device 10 selects an arbitrary route from among currently available network routes.

[0171] In this embodiment, the application specifies conditions such as minimum delay time and minimum jitter as dynamic characteristics, but the conditions are not limited to these. For example, the application may specify conditions using specific numerical values. For example, the application may specify conditions for dynamic characteristics by specifically limiting numerical values, such as that the delay time is equal to or less than a predetermined time, or that the jitter value is equal to or less than a predetermined value.

[0172] When the management device 10 is able to establish a route that satisfies the conditions, an ID that uniquely specifies the route is substituted for the PathID. When the communication device 30 learns the status of the route, the communication device 30 specifies the route by this PathID. This PathID may correspond to, for example, the dynamic characteristic information described above.

[0173] The management device 10 notifies the communication device 30 of ret as a return value of SetDeliveryPath(). This return value may correspond to the dynamic characteristic information described above, for example. Alternatively, an ID that uniquely specifies a route set in PathID may correspond to the dynamic characteristic information. ret is a return value that indicates the result of a route search by the management device 10. For example, a value of 0 or 1 is set as ret.

[0174] When "0" is set as the return value, it indicates that the management device 10 was able to establish a route that satisfies the conditions. When "1" is set as the return value, it indicates that the management device 10 was unable to establish a route that satisfies the conditions.

[0175] In this way, SetDeliveryPath() has a function of preferentially selecting a route having the characteristics specified by the application in Mode. If the route selection by the management device 10 is successful, 0 is returned to ret, and a value that identifies the route is set to PathID.

[0176] When an application (or an application creator) selects a Mode according to the use case of the application (e.g., video distribution) and executes SetDeliveryPath(), the management device 10 on the network side that provides the API automatically selects a route according to the use case.

[0177] In this manner, in the communication system according to this embodiment, an application selects a mode corresponding to a use case and executes this API, so that the management device 10 automatically selects and secures a route according to the application, and provides the optimal route to the application.

[0178] Therefore, even if the application creator does not have knowledge of which route will satisfy certain dynamic characteristic conditions (e.g., low latency) when selected, or how to select the route, the application can transmit data via the optimal communication route.

[0179] <3-2.GetPathList()> 13 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. This API, GetPathList( ), is an API that an application can use to acquire a list of paths from a SourceNode to a DestinationNode.

[0180] GetPathList() has a role of acquiring a list of paths from a SourceNode to a DestinationNode. That is, the communication device 30 may use this API to acquire a list of paths from a source node to a destination node.

[0181] GetPathList() takes, for example, SourceNode and DestinationNode as arguments. SourceNode is an optional argument.

[0182] SourceNode is an argument indicating the data source node. A value (e.g., a source address) that uniquely specifies the source node is set in SourceNode. If SourceNode is omitted, the node on which the application is being executed (i.e., the node to which the communication device 30 that executes the application is connected) is set as the source.

[0183] DestinationNode is an argument that indicates the node to which data is to be sent (destination). DestinationNode represents an address that can uniquely identify a node on a network.

[0184] The management device 10 notifies the communication device 30 of the PathIDList as a return value of GetPathList(). This return value may correspond to the dynamic characteristic information described above, for example. The PathIDList is a list that uniquely indicates the number of routes from a SourceNode to a DestinationNode and the routes.

[0185] In this way, GetPathList() has a function of specifying the paths from the SourceNode to the DestinationNode as a list. An application can obtain a list of paths from the SourceNode to the DestinationNode by using this API. The application can search (select) a path having desired characteristics from this list and perform data communication via that path.

[0186] If an application selects a route using its own algorithm rather than the automatic selection by SetDeliveryPath(), it can use GetPathList() to find out what routes are available.The application can then use this list to check the information and status of each route and determine the optimal route for the application.

[0187] <3-3.GetPathStatus()> 14 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. This API, GetPathStatus(), is an API that provides the status of a path to an application.

[0188] GetPathStatus() has the role of obtaining information about the status of a network path specified by the argument PathID. That is, the communication device 30 may use this API to obtain information about the status of a desired path.

[0189] GetPathStatus() takes, for example, a PathID as an argument. The PathID is a value that uniquely specifies a route.

[0190] The management device 10 notifies the communication device 30 of PathStatus as a return value of GetPathStatus(). This return value may correspond to the dynamic characteristic information described above, for example. PathStatus is a return value that indicates the state of a network path. For example, a value from 0 to 4 is set as a value that indicates the state.

[0191] "0" indicates that the specified route is active (available for use). "1" indicates that the specified route is using (being used by the application). In other words, if the return value of GetPathStatus() is "1", the application that sent GetPathStatus() is using the route specified by the argument PathID.

[0192] "2" indicates that the specified route is occupied (used by another application). In other words, when the return value of GetPathStatus() is "2", an application other than the application that sent GetPathStatus() is using the route specified by the argument PathID.

[0193] "3" indicates that the specified route is unselectable (cannot be selected by the application). In other words, if the return value of GetPathStatus() is "3", the application that sent GetPathStatus() cannot select the route specified by the argument PathID.

[0194] "4" indicates that the specified route is unavailable. In other words, if the return value of GetPathStatus() is "4", the route specified by the argument PathID cannot be used due to a failure or other reason.

[0195] In this way, GetPathStatus() has a function of checking the state of a route (for example, whether or not the route can be selected), such as whether the network route specified by the PathID from the application can be selected.

[0196] An application can find out the status of a specified network route by specifying the network route and executing GetPathStatus().

[0197] <3-4.GetPathInformation()> 15 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. This API, GetPathInformation(), is an API that an application can use to acquire dynamic characteristics (e.g., parameters related to delay and jitter) of a transmission path.

[0198] GetPathInformation() serves as an API that returns network characteristic information, that is, the communication device 30 can use this API to obtain dynamic characteristics of a network path.

[0199] GetPathInformation() takes, for example, a PathID as an argument. PathID is an optional argument. PathID takes a value that specifies the network route about which you want to know the dynamic characteristics information. If PathID is omitted, it is assumed that the PathID of the route currently being used by the application has been specified.

[0200] The management device 10 notifies the communication device 30 of, for example, an array or a pointer indicating a memory area in which network status information (dynamic characteristics) is stored as a return value of GetPathInformation(). This return value may correspond to, for example, the dynamic characteristic information described above. The network status information includes, for example, at least one of PathID, effective delay time, variance value of delay variation (jitter value), cost, power consumption, and the like.

[0201] In this way, GetPathInformation() has the function of acquiring characteristic information of the route specified by PathID. By using this API, an application can acquire dynamic characteristics of the route specified by PathID, including delay time, jitter value, etc.

[0202] In this way, an application can obtain information about the dynamic characteristics of a route by specifying the route for which it wishes to obtain parameters related to the dynamic characteristics using the PathID and executing GetPathInformation().

[0203] The method of calculating the dynamic characteristics depends on the implementation on the network side (for example, the management device 10). The management device 10 refers to the characteristics information database 121, for example, and calculates the return value of GetPathInformation().

[0204] As described above, in the APN 40, the dynamic characteristics are almost determined by the static characteristics of the route, and the fluctuation range is small, so that the management device 10 can estimate the dynamic characteristics of the APN 40 with high accuracy.

[0205] Therefore, the management device 10 can notify the application of a reliable return value that can serve as a criterion for the application to select a route.

[0206] Also, for example, the time range for measuring the delay time and jitter value, which are examples of dynamic characteristics, depends on the implementation on the network side. The management device 10 may notify the application of the delay time and jitter value, for example, the worst value at the time of design as a fixed value. Alternatively, the management device 10 may calculate the delay time and jitter value based on the actual measurement value within a certain time range, such as the most recent few minutes.

[0207] Also, here, GetPathInformation() is an API that simultaneously notifies an application of multiple parameters such as delay time and jitter value, but the API for acquiring dynamic characteristics is not limited to this.

[0208] For example, in a communication system, an API for individually acquiring each parameter of the dynamic characteristics, such as an API for acquiring a delay time, an API for acquiring a jitter value, etc., may be defined.

[0209] <3-5.ChangePathStatus()> 16 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. This API, ChangePathStatus(), is an API that an application can use to set the status of a path specified by a PathID, for example, to usable (selectable) or unselectable.

[0210] ChangePathStatus() serves as an API for changing the status of a network path, that is, the communication device 30 can use this API to change the status of a network path.

[0211] ChangePathStatus() takes, for example, PathID and Pathstatus as arguments. PathID takes a value that specifies the network path whose status is to be changed.

[0212] PathStatus takes a value that specifies the status of a network route. For example, PathStatus is used to set whether the route specified by PathID is selectable or not selectable. Routes that an application sets as not selectable are explicitly excluded from the options for automatic route selection in SetDeliveryPath() described above.

[0213] For example, a value of 0 or 1 is set as PathStatus. "0" indicates that it is selectable (active). In other words, when "0" is set as PathStatus, the route specified by PathID is set to be selectable. "1" indicates that it is unselectable. In other words, when "1" is set as PathStatus, the route specified by PathID is set to be unselectable.

[0214] The management device 10 notifies the communication device 30 of ret as a return value of ChangePathStatus(). This return value may correspond to, for example, the dynamic characteristic information described above. ret represents the result of changing the state of the path. For example, a value of 0 or 1 is set as ret.

[0215] If the return value is set to "0", it indicates "succeeded", that is, the change to the state of the route specified by PathID was successful. If the return value is set to "1", it indicates "failed", that is, the change to the state of the route specified by PathID failed. For example, if the route specified by PathID is being used by another application or is unavailable due to a failure, the change to the state of that route to selectable (active) will fail, and the return value will be set to "1".

[0216] In this way, ChangePathStatus() has the role of setting whether the network route of the specified PathID is selectable (usable) or not selectable by the application when the application that issues this API uses the network.

[0217] By using this API, an application can explicitly disable the selection of a specific route. This allows the application to narrow down the route options when executing SetDeliveryPath(), making it more likely that a route with the dynamic characteristics desired by the application will be automatically selected. In this way, by using ChangePathStatus(), an application can control automatic route selection to some extent.

[0218] <3-6.SetPath()> 17 is a diagram for explaining another example of an API according to an embodiment of the present disclosure. This API, SetPath(), is an API that an application can use to secure a path specified by a PathID.

[0219] SetPath() has a role of setting a network path to be used in an application. That is, the communication device 30 may use this API to use a network path for communication, for example.

[0220] SetPath() takes, for example, a PathID as an argument. The PathID takes a value that specifies the network path to be used by the application.

[0221] The management device 10 notifies the communication device 30 of ret as a return value of SetPath(). This return value may correspond to, for example, the dynamic characteristic information described above. ret represents the result of securing the network path specified by PathID. For example, a value of 0 or 1 is set as ret.

[0222] The return value "0" indicates "succeeded," i.e., the route specified by PathID was successfully secured. The return value "1" indicates "failed," i.e., the route specified by PathID was not successfully secured.

[0223] In this way, SetPath() has the role of enabling an application that issues this API to occupy the network path of the PathID specified in the argument and use it for data transmission.

[0224] Applications can use this API to secure a network path (communication path) to be used for data transmission, allowing the application to start data transmission using the secured network path.

[0225] <3-7.OnPathChanged> The event OnPathChanged is an event that notifies an application when a route that the application can use is set, or when a route that the application is using is automatically changed due to a network failure or the like.

[0226] For example, when a network path used by an application is set by SetDeliveryPath() or SetPath(), an event occurs to notify the application of the state change. Alternatively, when a path used by an application is automatically changed due to a network failure or the like, an event occurs to notify the application of the state change. When an event occurs, the management device 10 notifies the application of that fact.

[0227] When this event occurs and a notification is received, the application is free to decide how to respond. In other words, when this event occurs, the application can take any action it wishes, such as checking the state of the route and changing the route as necessary, or stopping data transmission.

[0228] <<4. Processing Example>> Next, an example of processing executed in the communication system according to the present embodiment will be described.

[0229] <4-1. Communication processing> Fig. 18 is a diagram for explaining an example of a communication process according to an embodiment of the present disclosure. Fig. 18 illustrates a communication process in which a transmitting device 30T transmits data to a receiving device 30R. Here, the transmitting device 30T is connected to a network node (node) A, and the transmitting device 30T is connected to a network node (node) I.

[0230] A management device 10 is disposed in each node of the APN 40. In the example of Fig. 18, a first management device 10_1 is disposed in a network node A, and a second management device 10_2 is disposed in a network node I.

[0231] First, the transmission device 30T acquires dynamic characteristic information from the first management device 10_1 arranged in the network node A by using an API (step S1). For example, the transmission device 30T executes the above-mentioned API, SetDeliveryPath(), to select and set a communication path that satisfies a desired dynamic characteristic.

[0232] That is, the transmitting device 30T requests the first management device 10_1 to set a route by specifying the condition of dynamic characteristics required for data transmission and to notify the PathID. The first management device 10_1 sets a route that satisfies the condition of dynamic characteristics specified by the transmitting device 30T among the routes between the transmitting device 30T and the receiving device 30R, i.e., from node A to node I. The first management device 10_1 notifies the transmitting device 30T of the success of the setting and of an ID (PathID) for identifying the set route as dynamic characteristic information.

[0233] The transmitting device 30T transmits data to the receiving device 30R through the communication path set by the first control device 10_1 (step S2).

[0234] Moreover, when an event occurs, for example, when a set route becomes unusable due to a fault or the like, the first control device 10_1 notifies the transmission device 30T of the event (step S3).

[0235] Upon receiving the event notification, the transmitting device 30T executes processing such as stopping data transmission and re-setting the route.

[0236] In this way, the transmission device 30T uses the API to set a route that satisfies the desired dynamic characteristics and communicates with the reception device 30R. This allows the transmission device 30T to perform data communication that makes use of the characteristics of the APN 40.

[0237] Incidentally, here, the transmitting device 30T requests the first management device 10_1 to set a route satisfying the desired dynamic characteristic, but the method of setting the route is not limited to this.

[0238] For example, the transmitting device 30T may use GetPathList() to acquire a list of paths from the transmitting device 30T (source node) to the receiving device 30R (destination node) from the first management device 10_1.

[0239] The transmission device 30T selects a route to be used for communication from among the selectable routes that satisfy the desired dynamic characteristics, for example, by using GetPathStatus() or GetPathInformation(). The transmission device 30T secures the selected route, for example, by using SetPath().

[0240] In this manner, the transmission device 30T may directly instruct the first control device 10_1 to secure a path to be used for communication. In this case, the transmission device 30T can perform data communication making use of the characteristics of the APN 40 by acquiring information on dynamic characteristics (dynamic characteristic information) from the first control device 10_1 using GetPathInformation().

[0241] Although the transmitting device 30T selects a route for performing data communication here, the receiving device 30R may select the route. In this case, for example, the receiving device 30R executes an API for the second management device 10_2 to select and set the route. The receiving device 30R notifies the transmitting device 30T of information (for example, a Path ID) on the set route. This allows the transmitting device 30T to perform data communication using the route set by the receiving device 30R.

[0242] Alternatively, the receiving device 30R may select a route, and the transmitting device 30T may set the route. In this manner, the communication device 30 that selects a route and the communication device 30 that sets the route may be different.

[0243] <4-2. Automatic route selection process> Fig. 19 is a flowchart showing an example of the flow of an automatic route selection process according to an embodiment of the present disclosure. The automatic route selection process shown in Fig. 19 is executed by the communication device 30 functioning as an application, for example, prior to the start of data communication.

[0244] First, the communication device 30 sets the address of the destination node in DestinationNode, which is an argument of the API, SetDeliveryPath( ) (step S101).

[0245] Next, the communication device 30 determines a Mode that matches the desired route characteristics (dynamic characteristics of the route) (step S102).

[0246] The communication device 30 calls the API, SetDeliveryPath() (step S103). As a result, the communication device 30 executes SetDeliveryPath() with the arguments set in steps S101 and S102.

[0247] The communication device 30 determines whether the execution of the API has ended normally (step S104). For example, the communication device 30 determines whether the execution of the API has ended normally based on the return value (ret value) of SetDeliveryPath().

[0248] If the ret value is 1 and the API has not ended normally (step S104; No), the communication device 30 changes the value set in Mode (step S105) and returns to step S103.

[0249] If the ret value is 0 and the API has ended normally (step S104; Yes), the communication device 30 acquires the PathID value of the selected route (step S106) and ends the process.

[0250] In this way, the communication device 30 can automatically select a route having desired dynamic characteristics by executing SetDeliveryPath().

[0251] <4-3. Route setting process> Fig. 20 is a flowchart showing an example of the flow of a route setting process according to an embodiment of the present disclosure. The route setting process shown in Fig. 20 is executed by the communication device 30 functioning as an application, for example, prior to the start of data communication.

[0252] First, the communication device 30 executes GetPathList() to acquire information on the route between a source node (SourceNode) and a destination node (DestinationNode) (step S201).

[0253] The communication device 30 acquires the characteristics of the paths listed in the acquired PathIDList by GetPathInformation( ) (step S202).

[0254] The communication device 30 determines a route (PathID) that matches the desired route characteristics (step S203). The communication device 30 calls an API, GetPathStatus(), that uses the determined route (PathID) as an argument (step S204).

[0255] The communication device 30 determines whether or not the path specified by the PathID is active based on the execution result of GetPathStatus() (step S205).

[0256] If the route specified by the PathID is not active (step S205; No), the communication device 30 determines another route (PathID) that matches the desired route characteristics (step S206), and returns to step S204.

[0257] On the other hand, if the route specified by the PathID is active (step S205; Yes), the communication device 30 executes SetPath() and specifies the route to be used for data transmission (step S207).

[0258] In this way, the communication device 30 can explicitly specify a route using the PathIDList.

[0259] In this embodiment, the communication device 30 determines a route that matches the route characteristics and checks the state of the determined route, but the route setting process performed by the communication device 30 is not limited to this. For example, the communication device 30 may extract active routes from the routes listed in the acquired PathIDList, and determine a route that matches the desired dynamic characteristics from among the extracted routes.

[0260] <4-4. Event processing> Fig. 21 is a flowchart showing an example of the flow of event processing according to an embodiment of the present disclosure. The event processing shown in Fig. 21 is executed, for example, when the communication device 30 functioning as an application receives an event notification from the management device 10. Here, the communication device 30 receives an OnPathChanged event as the event notification.

[0261] When receiving the OnPathChanged event, the communication device 30 executes, for example, GetPathInformation() to acquire characteristic information (dynamic characteristics) of the automatically changed, i.e., currently selected, route (step S301).

[0262] The communication device 30 determines whether the automatically changed route satisfies desired characteristics based on the acquired characteristic information (step S302).

[0263] If the automatically changed route satisfies the desired characteristics (step S302; Yes), the communication device 30 continues data transmission via the automatically selected route (step S303).

[0264] If the automatically changed route does not satisfy the desired characteristics (step S302; No), the communication device 30 determines another route (Path ID) that matches the desired route characteristics (dynamic characteristics) (step S304). The communication device 30 determines another route, for example, in the same manner as the route setting process of FIG.

[0265] Next, the communication device 30 specifies a path to be used for data transmission by SetPath() (step S305). The communication device 30 specifies the different path (PathID) determined in step S304 by SetPath().

[0266] As a result, even if the communication path is automatically changed due to a failure or the like, the communication device 30 can continue data transmission via a communication path that satisfies the desired dynamic characteristics.

[0267] Note that the process of the communication device 30 after the event notification is performed is arbitrary. Therefore, a process other than the process shown in Fig. 21 may be performed. For example, when the communication device 30 receives the event notification, the communication device 30 may stop data transmission regardless of the dynamic characteristics of the automatically selected route.

[0268] Alternatively, when an event notification is received, the communication device 30 may stop data transmission if a route satisfying the desired dynamic characteristics cannot be set. Also, when an event notification is received, the communication device 30 may continue data transmission, for example, by using a route that does not satisfy the desired dynamic characteristics, even if a route satisfying the desired dynamic characteristics cannot be set.

[0269] The communication device 30 may determine the operation to be performed after the event notification depending on, for example, the application being executed.

[0270] As described above, the communication device 30 according to this embodiment communicates with other communication devices 30 via an optical network (for example, the APN 40).

[0271] The control unit 330 uses an API to request the management device 10, which is placed at a node of the optical network and manages the dynamic characteristics of the transmission paths of the optical network, to send dynamic characteristic information regarding the dynamic characteristics of the communication path between other communication devices 30.

[0272] The control unit 330 acquires the dynamic characteristic information from the management device 10 .

[0273] This allows the communication device 30 to perform communication according to the characteristics of the optical network.

[0274] <<5. Other embodiments>> The above-described embodiment is merely an example, and various modifications and applications are possible. The processing according to each of the above-described embodiments may be implemented in various different forms (modifications) other than the above-described embodiments. For example, the system configuration is not limited to the above-described examples, and may be in various forms.

[0275] For example, in the above-described communication system, the management device 10 is placed at each node of the APN 40, and the communication device 30 connects to the APN 40 by connecting to the management device 10, but the communication device 30 may also be placed at a node of the APN 40.

[0276] In this case, the communication device 30 is arranged in the same node as the management device 10. The management device 10 and the communication device 30 may configure a network node as one device (or system). Alternatively, the management device 10 and the communication device 30 may configure a network node as separate devices.

[0277] 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 multiple paths between a transmitting node (a source node) and a receiving node (a destination node). That is, the transmitting device 30T selects one of the multiple paths to transmit data.

[0278] However, from the viewpoint of acquiring the dynamic characteristics of the communication path, the communication path according to the present embodiment does not need to exist in a plurality of ways. That is, the APN 40 does not need to be a mesh network, and there may be only one communication path between the transmitting node and the receiving node.

[0279] In this way, even if there is one communication path, the communication device 30 can acquire the dynamic characteristics of the communication path via the API, and thereby the communication device 30 can transmit data according to the dynamic characteristics of the communication path.

[0280] The management device 10 of this embodiment or the control device that controls the communication device 30 may be realized by a dedicated computer system or a general-purpose computer system.

[0281] For example, a communication program for executing the above-mentioned 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 program is installed in a computer and the above-mentioned processing is executed to configure a control device. In this case, the control device may be a device external to the management device 10 or the communication device 30 (for example, a personal computer). Also, the control device may be a device internal to the management device 10 or the communication device 30 (for example, the control unit 130 or the control unit 330).

[0282] The communication program may be stored in a disk device provided in a server device on a network such as the Internet, and may be downloaded to a computer. The above-mentioned functions may be realized by cooperation between an OS (Operating System) and application software. In this case, the parts other than the OS may be stored on a medium and distributed, or the parts other than the OS may be stored in a server device and may be downloaded to a computer.

[0283] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically by a known method. In addition, the information including the processing procedures, specific names, various data and parameters shown in the above documents and drawings can be changed arbitrarily unless otherwise specified. For example, the various information shown in each drawing is not limited to the illustrated information.

[0284] In addition, each component of each device shown in the figure is a functional concept, and does not necessarily have to be physically configured as shown in the figure. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of them can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc. This distribution and integration configuration may be performed dynamically.

[0285] The above-described embodiments can be appropriately combined in an area where the processing contents are not contradictory. The order of each step shown in the sequence diagrams of the above-described embodiments can be appropriately changed.

[0286] Furthermore, for example, the present embodiment can be implemented as any configuration constituting an apparatus or system, such as a processor as a system LSI (Large Scale Integration), a module using multiple processors, a unit using multiple modules, a set in which other functions are added to a unit, and the like (i.e., a configuration of a part of an apparatus).

[0287] In this embodiment, a system refers to a collection of multiple components (devices, modules (parts), etc.), regardless of whether all the components are in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device in which multiple modules are housed in a single housing, are both systems.

[0288] Also, for example, this embodiment can have a cloud computing configuration in which one function is shared and processed jointly by a plurality of devices via a network.

[0289] <<6. Conclusion>> Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments as they are, and various modifications are possible without departing from the gist of the present disclosure. In addition, components of different embodiments and modifications may be appropriately combined.

[0290] Furthermore, the effects of each embodiment described in this specification are merely examples and are not limiting, and other effects may also be provided.

[0291] The present technology can also be configured as follows. (1) A communication device that communicates with other communication devices via an optical network, requesting a management device that is disposed in a node of the optical network and manages dynamic characteristics of a transmission path of the optical network to transmit dynamic characteristic information regarding the dynamic characteristics of a communication path between the other communication device and the management device using an API (Application Programming Interface); A control unit that acquires the dynamic characteristic information from the management device. A communication device comprising: (2) The communication device according to (1), wherein the control unit acquires information regarding at least one of a delay characteristic and a jitter characteristic of the communication path as the dynamic characteristic information. (3) The communication device according to (1) or (2), wherein the control unit acquires information regarding the communication path that satisfies a predetermined dynamic characteristic as the dynamic characteristic information. (4) The communication device according to (3), wherein the control unit acquires information regarding the communication path that satisfies a predetermined delay time as the dynamic characteristic information. (5) The communication device according to (3) or (4), wherein the control unit acquires information regarding the communication path that satisfies a predetermined amount of jitter as the dynamic characteristic information. (6) The communication device according to any one of (1) to (5), wherein the control unit acquires information on the communication path that satisfies a predetermined condition as the dynamic characteristic information. (7) The communication device according to (6), wherein the control unit acquires information regarding the communication path that satisfies a predetermined communication cost as the dynamic characteristic information. (8) The communication device according to (6) or (7), wherein the control unit acquires information regarding the communication path that satisfies a predetermined power consumption as the dynamic characteristic information. (9) The communication device according to any one of (1) to (8), wherein the control unit receives a notification from the management device. (10) The communication device according to (9), wherein the management device transmits the notification to the communication device when 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 when 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 in a node of an optical network, receiving a transmission request for dynamic characteristic information regarding dynamic characteristics of a communication path between a second communication device that communicates with a first communication device via the optical network, via an API; obtaining the dynamic characteristics of the communication path; a control unit that transmits the dynamic characteristic information to the second communication device based on the acquired dynamic characteristic. A management device comprising: (14) The management device according to (13), wherein the control unit acquires the dynamic characteristics from a database that stores the dynamic characteristics. (15) The management device according to (14), wherein the database stores the dynamic characteristics for each of a plurality of paths in the optical network. (16) A communication method for a communication device that communicates with another communication device via an optical network, comprising: requesting a management device that is disposed in a node of the optical network and manages dynamic characteristics of a transmission path of the optical network to transmit dynamic characteristic information regarding dynamic characteristics of a communication path between the management device and the other communication device using an API; acquiring the dynamic characteristic information from the management device; A communication method including: (17) A communication method for a management device disposed in a node of an optical network, comprising: receiving a transmission request for dynamic characteristic information regarding dynamic characteristics of a communication path between a second communication device that communicates with a first communication device via the optical network and the first communication device via an API; obtaining the dynamic characteristics of the communication path; Sending the dynamic characteristic information to the second communication device based on the acquired dynamic characteristic; A communication method including: [Explanation of symbols]

[0292] 10 Management device 30 Communication Equipment 110,310 Communications Department 120,320 storage section 121 Characteristics Information Database 130,330 Control section 131 Request acquisition part 132 Characteristics Acquisition Unit 133 Generation part 134 Notification Department 331 Information Acquisition Department 332 Route Selection Unit 333 Communication Control Unit

Claims

1. A communication device that communicates with other communication devices via an optical network, requesting a management device that is disposed in a node of the optical network and manages dynamic characteristics of a transmission path of the optical network to transmit dynamic characteristic information regarding the dynamic characteristics of a communication path between the other communication device and the management device using an API (Application Programming Interface); A control unit that acquires the dynamic characteristic information from the management device. A communication device comprising:

2. The communication device according to claim 1 , wherein the control unit acquires, as the dynamic characteristic information, information relating to at least one of a delay characteristic and a jitter characteristic of the communication path.

3. The communication device according to claim 1 , wherein the control unit acquires information about the communication path that satisfies a predetermined dynamic characteristic as the dynamic characteristic information.

4. The communication device according to claim 3 , wherein the control unit acquires information about the communication path that satisfies a predetermined delay time as the dynamic characteristic information.

5. The communication device according to claim 3 , wherein the control unit acquires information about the communication path that satisfies a predetermined amount of jitter as the dynamic characteristic information.

6. The communication device according to claim 1 , wherein the control unit acquires information about the communication path that satisfies a predetermined condition as the dynamic characteristic information.

7. The communication device according to claim 6 , wherein the control unit acquires information about the communication path that satisfies a predetermined communication cost as the dynamic characteristic information.

8. The communication device according to claim 6 , wherein the control unit acquires information about the communication path that satisfies a predetermined power consumption as the dynamic characteristic information.

9. The communication device according to claim 1 , wherein the control unit receives a notification from the management device.

10. The communication device according to claim 9 , wherein the management device transmits the notification to the communication device when the dynamic characteristic information is changed.

11. The communication device according to claim 9 , wherein the management device transmits the notification to the communication device when the communication path selected by the communication device is changed.

12. The communication device of claim 1 , wherein the optical network is an All-Photonics Network (APN).

13. A management device disposed in a node of an optical network, receiving a transmission request for dynamic characteristic information regarding dynamic characteristics of a communication path between a second communication device that communicates with a first communication device via the optical network, via an API; obtaining the dynamic characteristics of the communication path; a control unit that transmits the dynamic characteristic information to the second communication device based on the acquired dynamic characteristic. A management device comprising:

14. The management device according to claim 13 , wherein the control unit acquires the dynamic characteristics from a database that stores the dynamic characteristics.

15. The management device according to claim 14 , wherein the database stores the dynamic characteristics for each of a plurality of paths in the optical network.

16. A communication method for a communication device that communicates with another communication device via an optical network, comprising: requesting a management device that is disposed in a node of the optical network and manages dynamic characteristics of a transmission path of the optical network to transmit dynamic characteristic information regarding dynamic characteristics of a communication path between the other communication device and the management device using an API; acquiring the dynamic characteristic information from the management device; A communication method including:

17. A communication method for a management device disposed in a node of an optical network, comprising: receiving a transmission request for dynamic characteristic information regarding dynamic characteristics of a communication path between a second communication device that communicates with a first communication device via the optical network and the first communication device via an API; obtaining the dynamic characteristics of the communication path; transmitting the dynamic characteristic information to the second communication device based on the acquired dynamic characteristic; A communication method including:

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