Information orientation network system, publisher node, router, system control method, and system control program

Abstract

To provide an information orientation network system, a publisher node, a router, a system control method, and a system control program that contribute to reliable content distribution.SOLUTION: In an information orientation network system, a publisher node once detecting a router in most recent connection relation changes as its device moves re-notifies a second router which newly enters into the most recent connection relation of possession of a content. A plurality of routes having been re-notified transfer the re-notification to other routers in connection relation respectively, and update their transfer destinations of a content request to the publisher node or router as the transfer source of the re-notification.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an information-centric network system, a publisher node, a router, a system control method, and a system control program. [Background technology]

[0002] A technology called information-centric networking (ICN) is being researched (see, for example, Patent Document 1). In this information-centric network, a router caches content distributed from a publisher node, and routing is performed based on the content name. Therefore, a subscriber node only needs to access any of the routers that store the content, which results in distributed access to publisher nodes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-091375 Summary of the Invention [Problem to be solved by the invention]

[0004] The following analysis has been made from the perspective of the present invention, and the disclosures of the above prior art documents are incorporated herein by reference.

[0005] As described above, in an information-centric network, access to publisher nodes is distributed, so even mobile nodes that are vulnerable to access concentration can be used as publisher nodes. However, if a publisher node moves, a problem occurs in that subscriber nodes cannot access the publisher node using routing based on content names.

[0006] Specifically, when a router holds content, it is sufficient for the subscriber node to be able to access that router, and access to the publisher node is not essential. Therefore, the publisher node is neglected as an access destination, and the movement of the publisher node is not followed.

[0007] However, because routers cache content, at some point the content will be deleted from all routers. Also, because routers cache content while relaying it, if the content has never been distributed from the publisher node, not all routers will have the content. In this case, access to the publisher node becomes necessary, but the publisher node's movement creates the problem of being unable to access the publisher node using routing based on the content name.

[0008] In other words, conventional information-centric networks have a problem in that content distribution becomes impossible due to the movement of publisher nodes.

[0009] Therefore, an object of the present invention is to provide an information-centric network system, a publisher node, a router, a system control method, and a system control program that contribute to reliable content distribution. [Means for solving the problem]

[0010] According to a first aspect of the present invention, a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting the content; The publisher node: a router detection unit that detects a router that is in a closest connection relationship among a plurality of routers; a notification unit that notifies a first router that is closest to the router that the first router has the content; a re-notification unit that, when detecting that a router in a closest connection relationship has changed due to movement of the device itself, re-notifies a second router that has newly become the closest connected router of possession of the content; Each of the plurality of routers a notification processing unit that, upon receiving the notification, transfers the notification to other routers with which it has a connection relationship, and registers the publisher node or router that transferred the notification in a storage unit as a transfer destination of content requests from subscriber nodes; a re-announcement processing unit that, upon receiving the re-announcement, transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of a content request to the publisher node or router that has transferred the re-announcement; An information-centric network system is provided.

[0011] According to a second aspect of the present invention, a router detection unit that detects a router that is in a closest connection relationship among a plurality of routers; a notification unit that notifies a first router that is closest to the router that the first router has the content; a re-notification unit that, when detecting that a router in a closest connection relationship has changed due to the movement of the device itself, re-notifies a second router that has newly become the closest connected router of the possession of the content; A publisher node having a publisher node is provided.

[0012] According to a third aspect of the present invention, a notification processing unit that, upon receiving a notification regarding the possession of content, transfers the notification to other routers with which it has a connection relationship, and registers the publisher node or router that transferred the notification in a storage unit as a transfer destination of content requests from subscriber nodes; a re-announcement processing unit that, upon receiving a re-announcement regarding the possession of the content, transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of a content request to the publisher node or router that transferred the re-announcement; A router is provided having:

[0013] According to a fourth aspect of the present invention, a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting content; In an information-centric network system including: The publisher node: Among multiple routers, the router with the closest connection relationship is detected, The first router in the closest connection relationship is notified of the possession of the content, When detecting that the router in the closest connection relationship has changed due to the movement of the device itself, the device re-notifies the second router that has become the new closest connection relationship that it possesses the content; Each of the plurality of routers Upon receiving the notification, the notification is forwarded to other routers having a connection relationship, and the publisher node or router that forwarded the notification is registered in the storage unit as a forwarding destination of content requests from subscriber nodes; Upon receiving the re-announcement, the router transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of content requests to the publisher node or router that transferred the re-announcement. A system control method is provided.

[0014] According to a fifth aspect of the present invention, a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting content; In an information-centric network system including: The publisher node, Among multiple routers, the router with the closest connection relationship is detected, The first router, which is the closest to the router, notifies the router of the possession of the content. When detecting that the router in the closest connection relationship has changed due to the movement of the device itself, the device re-notifies the second router that has become the new closest connection relationship that it possesses the content; In each of the plurality of routers, When the notification is received, the notification is transferred to another router having a connection relationship, and the publisher node or router that transferred the notification is registered in the storage unit as a transfer destination of content requests from the subscriber node; When receiving the re-announcement, the re-announcement is forwarded to other routers with which the router has a connection relationship, and the forwarding destination of the content request is updated to the publisher node or router that forwarded the re-announcement. A system control program is provided. [Effects of the Invention]

[0015] According to each aspect of the present invention, there are provided an information-centric network system, a publisher node, a router, a system control method, and a system control program that contribute to reliable content distribution. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram for explaining an overview. [Figure 2] FIG. 1 illustrates an example of a router. [Figure 3] FIG. 2 illustrates an example of a publisher node. [Figure 4] FIG. 10 is a diagram for explaining notification processing. [Figure 5] FIG. 10 is a diagram for explaining a re-notification process. [Figure 6] FIG. 10 is a diagram illustrating an example of a processing flow by a publisher node. [Figure 7] FIG. 10 is a diagram illustrating an example of a processing flow by a node. [Figure 8] FIG. 10 is a diagram illustrating content distribution when a publisher node is not moving. [Figure 9]FIG. 10 is a diagram illustrating content distribution after a publisher node has moved. [Figure 10] FIG. 1 illustrates a conventional technique. [Figure 11] FIG. 10 is a diagram for explaining notification processing. [Figure 12] FIG. 10 is a diagram for explaining a re-notification process. [Figure 13] FIG. 1 illustrates an example of a computer as a publisher node. [Figure 14] FIG. 1 illustrates an example of a computer serving as a router. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the reference numerals used in the following description are used for convenience to identify each element as an example to facilitate understanding, and are not intended to limit the present invention to the illustrated embodiment. Furthermore, the connecting lines between blocks in each drawing include both bidirectional and unidirectional lines. Unidirectional arrows are used to schematically indicate the flow of the main signal (data) and do not exclude bidirectionality. Furthermore, although not explicitly shown, input and output ports exist at the input and output ends of each connecting line in the circuit diagrams, block diagrams, internal configuration diagrams, connection diagrams, and the like shown in this disclosure. The same applies to input and output interfaces.

[0018] An overview of the present invention will now be described. As shown in Fig. 1, an information-centric network system 100 includes a publisher node 10 that distributes content, a plurality of routers 20 that constitute the information-centric network, and a subscriber node 30 that requests content.

[0019] Publisher node 10 has router detection unit 11, notification unit 12, and re-notification unit 13. Router detection unit 11 detects the closest connected router among multiple routers 20. Notification unit 12 notifies the closest connected first router of its possession of content. When re-notification unit 13 detects that the closest connected router has changed due to movement of its own device, it re-notifies the second router that has newly become the closest connected router of its possession of content.

[0020] Each router 20 has a notification processing unit 21 and a re-notification processing unit 22. When the notification processing unit 21 receives a notification, it forwards the notification to other routers with which it has a connection relationship, and registers the publisher node 10 or router 20 that forwarded the notification in a storage unit as a forwarding destination of content requests from the subscriber node 30. When the re-notification processing unit 22 receives a re-notification, it forwards the re-notification to other routers with which it has a connection relationship, and updates the forwarding destination of content requests to the publisher node 10 or router 20 that forwarded the re-notification.

[0021] It should be noted that "router 20" is a general term for each router, and includes "first router," "second router," "other router," etc., but the reference numerals will be omitted as appropriate to avoid confusion.

[0022] In the above-described information-centric network system 100, even if the publisher node 10 moves, the subscriber node 30 will notify the publisher node 10 again at the new location, eliminating the problem of the subscriber node 30 being unable to access the publisher node 10.

[0023] [Embodiment 1] The information-centric network system 100 described above will be explained below using a specific example.

[0024] Similar to the overview above, the information-centric network system 100 includes a publisher node 10 , a plurality of routers 20 , and a subscriber node 30 .

[0025] As shown in Fig. 2, each router 20 has an announcement processing unit 21, a re-announcement processing unit 22, and a memory, as well as general components (such as ports, not shown) for fulfilling the functions of the router 20. Two tables called a Forwarding Information Base (FIB) and a Pending Interest Table (PIT) are stored in the memory. When distinguishing between routers, they are referred to as "router A" and the reference numerals are omitted as appropriate. Reference numerals are also omitted for "other routers" and "routers in the closest connection relationship (closest routers)" to avoid confusion.

[0026] The FIB is a table that associates content names (Name) with forwarding destinations (Next) of content requests from the subscriber node 30. For example, for router B in Fig. 4, this means that a content request with content name: data-P is forwarded to router C. Overall, based on the content name: data-P, the content request is routed (relayed and forwarded) from subscriber node 30 to router A to router B to router C to publisher node 10.

[0027] The PIT is a table related to unresolved content requests, and registers the content name (Name) written in the content request and the node (Requested) that accepted the content request. For example, for router B in FIG. 8, this means that a content request for content name: data-P has been accepted from router A, but is unresolved. Here, when router B receives the content (data-P) itself, it refers to the PIT and forwards the received content (data-P) to router A. Overall, content is distributed in the following order based on content name: data-P: publisher node 10 → router C → router B → router A → subscriber node 30.

[0028] The notification processing unit 21 transfers the notification and registers the information in the FIB. For example, router B in FIG. 4 receives a notification from router C that publisher node 10 has content name: data-P. At that time, router B transfers the notification to routers A and E. Router B also registers content name: data-P in Name in the FIB, and registers router C in Next. By performing these processes, the FIB of router B becomes as shown in FIG. 4.

[0029] The re-announcement processing unit 22 transfers the re-announcement and updates the FIB. For example, suppose that the publisher node 10 moves from the state shown in FIG. 4 to the state shown in FIG. 5. At this time, for example, router B in FIG. 4 receives a re-announcement from router E indicating that publisher node 10 holds content name: data-P. At this time, router B transfers the re-announcement to routers A and C. Router B also updates Next for content name: data-P in the FIB to router E. By performing this processing, the FIB of router B is updated to that shown in FIG. 5.

[0030] 5, a content request from the subscriber node 30 is routed from the subscriber node 30 to the router A, router B, router E, and then to the publisher node 10 based on the content name: data-P. The content is also distributed from the publisher node 10 to the router E, router B, router A, and then to the subscriber node 30 based on the content name: data-P.

[0031] The publisher node 10 is exemplified by, for example, a smartphone. Specifically, as shown in Fig. 3, the publisher node 10 has a router detection unit 11, a notification unit 12, a re-notification unit 13, and a memory, as well as general components (such as a communication function, not shown) for fulfilling the functions of the publisher node 10. Note that, since the present application is premised on the fact that the publisher node 10 is mobile, it is considered that the publisher node 10 and the router 20 are connected wirelessly, but a wired connection is also possible.

[0032] The router detection unit 11 detects router C as the router with the closest connection relationship in Fig. 4. Also, the router detection unit 11 detects router E as the router with the closest connection relationship in Fig. 5. Note that hereinafter, the router with the closest connection relationship will be referred to as the "closest router."

[0033] Various existing technologies can be applied to detect the nearest router. For example, existing smartphones have a function to automatically detect and switch to the optimal access point. This optimal access point may be considered the nearest router. Alternatively, the router detection unit 11 may periodically make an inquiry to the currently connected router 20. Here, the router 20 that first responds to the inquiry can be said to be the nearest router, and if the router 20 that responded is different from the previous time, the router detection unit 11 can determine that the router in the nearest connection relationship has changed.

[0034] The notification unit 12 notifies the first router, which is the closest router in the connection relationship, that it possesses the content. Fig. 4 shows the state after the notification unit 12 has notified router C, which acts as the "first router," that it possesses the content:data-P. Note that the trigger for the notification by the notification unit 12 may be, for example, the storage of content by the content distributor or an instruction to distribute the content.

[0035] The re-notification unit 13 re-notifies the second router, which has now become the nearest connected router, of the possession of the content. Figure 5 shows the state after the re-notification unit 13 has re-notified router E, acting as the "second router," of the possession of the content:data-P. This re-notification updates the FIBs of routers B, C, and E.

[0036] The subscriber node 30 is a node that acquires content, and is exemplified by a smartphone, for example.

[0037] An example of the flow of processing by the publisher node 10 and the router 20 will be described below.

[0038] As shown in Fig. 6, when content is stored in the publisher node 10 (step S11, Yes), the publisher node 10 detects the router 20 that is closest to the publisher node 10 (step S12). The publisher node 10 then notifies the detected closest router (first router) that it owns the content (step S13). Thereafter, the publisher node 10 periodically detects the closest router (step S14, No). Here, if the publisher node 10 detects that the closest router has changed due to movement of the publisher node 10 (step S14, Yes), the publisher node 10 again notifies the second router, which has newly become the closest router, that it owns the content (step S15).

[0039] 7, when the router 20 receives a notification (step S21, Yes), it registers the information in the FIB (step S22). After that, when the router 20 receives another notification (step S23, Yes), it updates the information in the FIB (step S24).

[0040] The content distribution process and the like follow the same flow as before.

[0041] The following describes the differences between the present invention and the prior art. First, in common with the present invention and the prior art, announcement is made by storing content in the publisher node 10, resulting in the state shown in FIG. 4. Here, when a request is made from the subscriber node 30 with the content name: data-P, the content request is routed from the subscriber node 30 to router A, router B, router C, and finally to the publisher node 10. At this time, the PIT of each router 20 is in the state shown in FIG. 8.

[0042] Suppose that publisher node 10 moves in the state shown in Figure 4. At this time, in the present invention, the FIB of router 20 is updated as shown in Figure 5 by re-notification from publisher node 10. Therefore, when content name: data-P is requested from subscriber node 30, the PIT of router 20 becomes as shown in Figure 9. In other words, the content request from subscriber node 30 is routed from subscriber node 30 to router A, router B, router E, and publisher node 10, and reaches publisher node 10.

[0043] On the other hand, in the conventional technology, the FIB of the router 20 remains as shown in Figure 4 even after the publisher node 10 has moved. Therefore, as shown in Figure 10, the content request is routed from the subscriber node 30 to router A, then router B, and then router C. Router C fails to send the content request because the publisher node 10, to which the content request is to be forwarded, no longer exists.

[0044] Such a failure to send a content request in the prior art can be said to be due to the publisher node 10 being neglected as an access destination and not being taken into consideration for its movement. In other words, the prior art assumes that the publisher node 10 is a fixed device such as a server, and does not assume that the publisher node 10 will move.

[0045] [Transformation] The FIB update based on the re-announcement may be the addition of information. For example, when Router B receives the re-announcement, it updates the Next entry in its FIB from "Router C" to "Router E." It may also add "Router E."

[0046] [Embodiment 2] In an information-centric network, content names may have a hierarchical name structure that includes an Internet domain name, and the movement of a publisher node 10 may require a change of domain name.

[0047] For example, content data-P from AAA Company may have the content name AAA.com / data-P. Here, suppose that publisher node 10 makes an announcement via router C1 installed within AAA Company. Then, suppose that publisher node 10 moves and makes a re-announcement via router C2 also installed within AAA Company, just like router C1. In this case, there is no problem with AAA.com / data-P, which means content distributed from within AAA Company.

[0048] However, if the re-announcement is made via Router E installed outside AAA, the content will no longer be distributed from within AAA, and so the domain name AAA.com / will need to be changed. However, changing the content name will cause problems in terms of publicizing the content name.

[0049] Therefore, the router detection unit 11 periodically inquires of the closest connected router about the network to which the device belongs. Furthermore, if the reply to the inquiry from the closest connected router is different from the previous reply, the re-notification unit 13 determines that the closest connected router 20 has changed due to the device's movement, and that the network to which the device belongs has also changed. The re-notification unit 13 then re-notifies the second router, which has now become the closest connected router, of the possession of the content. In particular, the notification unit 12 notifies the content name, and the re-notification unit 13 notifies the second router of another content name, while re-notifying that the other content name is the same as the content name already notified by the notification unit.

[0050] A specific example will be explained. As shown in Fig. 11, the network to which routers C1 to C3 belong is considered to be the local area network of AAA company. It is assumed that publisher node 10 announces the content name: AAA.com / data-P when the nearest router is router C1. At this time, the FIBs of routers A and the like are in the state shown in Fig. 11. Furthermore, publisher node 10 inquires of router C1 about the network to which it belongs, and receives a response from router C1 indicating that it belongs to the local area network of AAA company.

[0051] Assume that publisher node 10 moves from the state shown in FIG. 11 and the nearest router becomes router E. At this time, publisher node 10 inquires of router E about the network to which it belongs and receives a response indicating that it belongs to a public network. Here, because the response from router E differs from the response from router C1, publisher node 10 determines that the nearest router has changed due to its own movement and that the network to which it belongs has also changed. Publisher node 10 then notifies router E of the content name: BBB.com / data-P. At this time, it re-notifies that content name: BBB.com / data-P is the same as content name: AAA.com / data-P.

[0052] At this time, the FIB of router 20 will be in the state shown in Figure 12. For example, in addition to the content name: AAA.com / data-P, the content name: (BBB.com / data-P) indicating that the content is the same is additionally registered in the Name field of the FIB of router B. Also, router E is additionally registered in the Next field of the FIB of router B. In this state, when a request for content name: AAA.com / data-P is received, router B will consider AAA.com / data-P = (BBB.com / data-P) and will forward the content request to both router C1 and router E.

[0053] As a result, even after the publisher node 10 moves and the content name: BBB.com / data-P is re-announced, a content request based on the content name: AAA.com / data-P will reach the publisher node 10 from the subscriber node 30. This eliminates the problem that the subscriber node 30 cannot access the publisher node 10.

[0054] [Embodiment 3] Assume that publisher node 10 announces content name: AAA.com / data-P via router C1, then moves and re-announces it via router C2. At this time, the re-announcement is sent to routers C1 to C3 within AAA's local area network, and the FIB is updated. In other words, even if routers A, B, D, and E receive the re-announcement, no changes occur in the FIB, so there is no need to forward the re-announcement to routers A, B, D, and E. Therefore, it is possible to leave the re-announcement at routers C1 to C3.

[0055] That is, the re-notification unit 13 detects that the response from the router C2 to the inquiry about the belonging network is the same as the previous response from the router C1, but that the nearest router has changed due to the movement of the own device (publisher node 10).At that time, the re-notification unit 13 re-notifies the routers C1 to C3 that belong to the same belonging network as the router C2 that has become the new nearest router that it possesses the content.

[0056] For example, it is conceivable to specify router 20 belonging to the local area network of AAA company as the destination of the re-announcement. As shown in Fig. 11, the local area network of AAA company is connected to the public network via router C1, but it is sufficient if router C1 does not forward the re-announcement to router B.

[0057] The load on the network is reduced because the range of the re-announcement transfer is narrowed.

[0058] The present invention can also be implemented as a program that causes a computer to execute processing. For example, a computer serving as publisher node 10 includes a memory, a CPU (Central Processing Unit), and an interface, as shown in Fig. 13. The CPU reads and executes the program of the present invention from the memory, thereby realizing processing modules corresponding to router detection unit 11, notification unit 12, and re-notification unit 13.

[0059] 14, the computer serving as the router 20 implements processing modules corresponding to a notification processing unit 21 and a re-notification processing unit 22. The memory stores an FIB and a PIT.

[0060] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes.

[0061] (Appendix 1) a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting the content; The publisher node: a router detection unit that detects a router that is in a closest connection relationship among a plurality of routers; a notification unit that notifies a first router that is closest to the router that the first router has the content; a re-notification unit that, when detecting that a router in a closest connection relationship has changed due to movement of the device itself, re-notifies a second router that has newly become the closest connected router of possession of the content; Each of the plurality of routers a notification processing unit that, upon receiving the notification, transfers the notification to other routers with which it has a connection relationship, and registers the publisher node or router that transferred the notification in a storage unit as a transfer destination of content requests from subscriber nodes; a re-announcement processing unit that, upon receiving the re-announcement, transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of a content request to the publisher node or router that has transferred the re-announcement; Information-oriented network systems.

[0062] (Appendix 2) The router detection unit periodically inquires of the nearest connected router about the network to which the router belongs, When the reply to the inquiry from the closest connected router is different from the previous reply, the re-notification unit determines that the closest connected router has changed due to the movement of the device itself, and that the network to which the device belongs has also changed, and re-notifies the second router that has newly become the closest connected router of the possession of the content. 10. The information-centric network system of claim 1.

[0063] (Appendix 3) the notification unit notifies the name of the content; the re-notification unit notifies the user of a different content name, and re-notifies the user that the different content name is the same as the content name already notified by the notification unit; 1. An information-centric network system as described in Appendix 2.

[0064] (Appendix 4) When the re-notification unit detects that the response to the inquiry from the closest connected router is the same as the previous response, but that the closest connected router has changed due to the device moving, the re-notification unit re-notifies the possession of the content to a router that belongs to the same network as the second router that has newly become the closest connected router. 1. An information-centric network system as described in Appendix 3.

[0065] (Appendix 5) a router detection unit that detects a router that is in a closest connection relationship among a plurality of routers; a notification unit that notifies a first router that is closest to the router that the first router has the content; a re-notification unit that, when detecting that a router in a closest connection relationship has changed due to the movement of the device itself, re-notifies a second router that has newly become the closest connected router of the possession of the content; A publisher node having

[0066] (Appendix 6) a notification processing unit that, upon receiving a notification regarding the possession of content, transfers the notification to other routers with which it has a connection relationship, and registers the publisher node or router that transferred the notification in a storage unit as a transfer destination of content requests from subscriber nodes; a re-announcement processing unit that, upon receiving a re-announcement regarding the possession of the content, transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of a content request to the publisher node or router that transferred the re-announcement; A router having:

[0067] (Appendix 7) a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting content; In an information-centric network system including: The publisher node: Among multiple routers, the router with the closest connection relationship is detected, The first router in the closest connection relationship is notified of the possession of the content, When detecting that the router in the closest connection relationship has changed due to the movement of the device itself, the device re-notifies the second router that has become the new closest connection relationship that it possesses the content; Each of the plurality of routers Upon receiving the notification, the notification is forwarded to other routers having a connection relationship, and the publisher node or router that forwarded the notification is registered in the storage unit as a forwarding destination of content requests from subscriber nodes; Upon receiving the re-announcement, the router transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of content requests to the publisher node or router that transferred the re-announcement. System control method.

[0068] (Appendix 8) a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting content; In an information-centric network system including: The publisher node, Among multiple routers, the router with the closest connection relationship is detected, The first router, which is the closest to the router, notifies the router of the possession of the content. When detecting that the router in the closest connection relationship has changed due to the movement of the device itself, the device re-notifies the second router that has become the new closest connection relationship that it possesses the content; In each of the plurality of routers, When the notification is received, the notification is transferred to another router having a connection relationship, and the publisher node or router that transferred the notification is registered in the storage unit as a transfer destination of content requests from the subscriber node; When receiving the re-announcement, the re-announcement is forwarded to other routers with which the router has a connection relationship, and the forwarding destination of the content request is updated to the publisher node or router that forwarded the re-announcement. System control program.

[0069] The features described in Supplementary Notes 2 to 4 above can also be applied to the publisher node in Supplementary Note 5, the router in Supplementary Note 6, the system control method in Supplementary Note 7, and the system control program in Supplementary Note 8.

[0070] The disclosures of the above-cited patent documents and other documents are incorporated herein by reference and may be used as the basis or part of the present invention, as necessary. Modifications and adjustments of the embodiments and examples are possible within the scope of the entire disclosure of the present invention (including the claims), and further based on the basic technical concepts thereof. Furthermore, various combinations and selections (including partial deletions) of the various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible within the scope of the entire disclosure of the present invention. In other words, the present invention naturally embraces various modifications and alterations that would be possible by a person skilled in the art in accordance with the entire disclosure and technical concepts, including the claims. In particular, with regard to the numerical ranges set forth herein, any numerical value or subrange within that range should be construed as specifically set forth, even if not otherwise specified. Furthermore, the disclosures of the above-cited documents, when used in part or in whole in combination with the disclosures herein as part of the disclosure of the present invention, in accordance with the spirit of the present invention, are also deemed to be included in the disclosures of this application. [Explanation of symbols]

[0071] 10 publisher nodes 11 Router detection section 12 Announcement Department 13 Re-announcement department 20 Router 21 Notification Processing Section 22 Re-notification processing section 30 subscriber nodes 100 Information-oriented Network System

Claims

1. a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting the content; The publisher node: a router detection unit that detects a router that is in a closest connection relationship among a plurality of routers; a notification unit that notifies a first router that is closest to the router that the content is held; a re-notification unit that, when detecting that a router in a closest connection relationship has changed due to movement of the device itself, re-notifies a second router that has newly become the closest connected router of possession of the content; Each of the plurality of routers a notification processing unit that, upon receiving the notification, transfers the notification to other routers with which it has a connection relationship, and registers the publisher node or router that transferred the notification in a storage unit as a transfer destination of content requests from subscriber nodes; a re-announcement processing unit that, upon receiving the re-announcement, transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of a content request to the publisher node or router that has transferred the re-announcement; Information-oriented network systems.

2. The router detection unit periodically inquires of the nearest connected router about the network to which the router belongs, When the reply to the inquiry from the closest connected router is different from the previous reply, the re-notification unit determines that the closest connected router has changed due to the movement of the device itself, and that the network to which the device itself belongs has also changed, and re-notifies the second router that has newly become the closest connected router of the possession of the content.

2. The information-centric network system according to claim 1.

3. the notification unit notifies the name of the content; the re-notification unit notifies the user of a different content name, and re-notifies the user that the different content name is the same as the content name already notified by the notification unit; 3. The information-centric network system according to claim 2.

4. When the re-notification unit detects that the response to the inquiry from the closest connected router is the same as the previous response, but that the closest connected router has changed due to the movement of the device, the re-notification unit re-notifies the possession of the content to a router that belongs to the same network as the second router that has newly become the closest connected router.

4. The information-centric network system according to claim 3.

5. a router detection unit that detects a router that is in a closest connection relationship among a plurality of routers; a notification unit that notifies a first router that is closest to the router that the content is held; a re-notification unit that, when detecting that a router in a closest connection relationship has changed due to the movement of the device itself, re-notifies a second router that has newly become the closest connected router of the possession of the content; A publisher node having

6. a notification processing unit that, upon receiving a notification regarding the possession of content, transfers the notification to other routers with which it has a connection relationship, and registers the publisher node or router that transferred the notification in a storage unit as a transfer destination of content requests from subscriber nodes; a re-announcement processing unit that, upon receiving a re-announcement regarding the possession of the content, transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of a content request to the publisher node or router that transferred the re-announcement; A router having:

7. a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting content; In an information-centric network system including: The publisher node: Among multiple routers, the router with the closest connection relationship is detected, The first router, which is the closest to the router, notifies the router of the possession of the content. When detecting that the router in the closest connection relationship has changed due to the movement of the device itself, the device re-notifies the second router that has become the new closest connection relationship that it possesses the content; Each of the plurality of routers Upon receiving the notification, the notification is forwarded to other routers having a connection relationship, and the publisher node or router that forwarded the notification is registered in the storage unit as a forwarding destination of content requests from subscriber nodes; Upon receiving the re-announcement, the router transfers the re-announcement to other routers with which it has a connection relationship, and updates the transfer destination of content requests to the publisher node or router that transferred the re-announcement. System control method.

8. a plurality of routers constituting an information-centric network; a publisher node that distributes content; a subscriber node requesting content; In an information-centric network system including: The publisher node, Among multiple routers, the router with the closest connection relationship is detected, The first router, which is the closest to the router, notifies the router of the possession of the content. When detecting that the router in the closest connection relationship has changed due to the movement of the device itself, the device re-notifies the second router that has become the new closest connection relationship that it possesses the content; In each of the plurality of routers, When the notification is received, the notification is transferred to another router having a connection relationship, and the publisher node or router that transferred the notification is registered in the storage unit as a transfer destination of content requests from the subscriber node; When receiving the re-announcement, the re-announcement is forwarded to other routers with which the router has a connection relationship, and the forwarding destination of the content request is updated to the publisher node or router that forwarded the re-announcement. System control program.

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