Communication systems and communication methods

Abstract

To provide, as one objective, a communication system capable of suppressing delay and for providing access to a network via a second network (for example, a Japanese carrier) to a wireless terminal storing an identification number for accessing a first network (for example, a European carrier).SOLUTION: A communication system 200A includes: a receiving unit that receives a connection start request on a C plane from a wireless terminal 100; a selection unit that selects a gateway 200B on a U plane to a computer network 130 connected to a second network 220 based on the network ID of the second network 220 in response to the connection start request; and a transmitting unit that transmits the gateway ID of the selected gateway 200B on the U-plane to the second network 220.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a communication system and a communication method.

Background Art

[0002] With the progress of globalization, the number of devices connected to computer networks such as the Internet has increased, and the concept of the Internet of Things in which all things are networked has become widespread. Hereinafter, a networked device is referred to as an "IoT device". There are various network connection methods for IoT devices, but here, attention is paid to the case of utilizing a cellular network.

[0003] It has also become common for IoT devices network-connected by a cellular network to be exported across national borders. For example, a case where a SIM card contracted with a mobile network operator (MNO) or carrier in Europe is inserted into a product at a factory in Europe and imported into Japan can be considered.

[0004] When this IoT device attempts to access a computer network in Japan, identification numbers such as IMSI and ICCID are assigned to the SIM card, and information for identifying the above European carrier, which is the home location, is associated with the identification number. Therefore, a connection start request to the computer network is transferred to the European carrier via a Japanese carrier that is interconnected with the European carrier.

[0005] More specifically, as shown in Figure 1, when a wireless terminal 100 with a SIM card contracted with European carrier 110 is located in the service area of ​​Japanese carrier 120 and initiates access to the IP network 130, the wireless terminal 100 first sends a connection initiation request, including the IMSI, to a gateway (SGSN in 3G, S-GW in LTE) deployed in the core network of Japanese carrier 120 (hereinafter also referred to as the "visiting gateway" or "visiting carrier gateway") via a wireless base station, which is the entry point of Japanese carrier 120.

[0006] Upon receiving a connection initiation request, the visiting gateway determines that the identification number is associated with a European carrier 110 other than the Japanese carrier 120. After authenticating the existence of a contract based on information such as the European carrier 110 and the SIM card inserted in the wireless terminal 100, it refers to the DNS based on the APN (Access Point Name) received from the wireless terminal 100 and obtains the IP address corresponding to that APN. This IP address points to the gateway (GGSN in 3G, P-GW in LTE) which is the endpoint of the European carrier 110's core network (hereinafter also referred to as the "home gateway" or "home carrier gateway"). The visiting gateway then transmits or forwards the connection initiation request to the home gateway over the C-plane of a tunneling protocol such as GTP via a network that provides inter-carrier interconnection, such as GRX, and a tunnel is formed between the visiting gateway of the Japanese carrier 120 and the home gateway of the European carrier 110. The communication from the wireless terminal 100 is forwarded from the Japanese carrier 120 to the European carrier 110 via the tunnel, and then forwarded from the European carrier 110 to an external IP network, etc. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] International roaming via inter-carrier interconnection networks such as GRX allows users to access communication services even outside the service area of ​​the carrier that issued the SIM card, as long as they are within the service area of ​​a partner carrier. However, as shown in the example in Figure 1, access must be routed through the home location, which increases the communication distance and the number of network hops, causing data communication delays. This is a problem also known as "triangular routing."

[0008] Similar problems can occur, for example, when SIM cards issued by European carriers are inserted into IoT devices such as in-car systems and used worldwide.

[0009] The present invention has been made in view of these problems, and its first objective is to provide a communication system or communication method for providing access to a network via a second network (e.g., a Japanese carrier) to a wireless terminal that has (directly or indirectly) stored an identification number for accessing a first network (e.g., a European carrier), and which can suppress delay.

[0010] Another object of the present invention is to provide a second network (e.g., a Japanese carrier) or a communication method for providing access to a first network (e.g., a European carrier) via itself to a wireless terminal that stores an identification number for accessing the first network (e.g., a European carrier), and which can suppress latency. [Means for solving the problem]

[0011] To achieve this objective, a first aspect of the present invention is a communication system for providing access to a network via a second network to a wireless terminal that stores an identification number for accessing a first network, the system comprising: a receiving unit that receives a connection start request on the C plane from the wireless terminal; a selection unit that, in response to the connection start request, selects a gateway on the U plane to the network connected to the second network based on the network ID of the second network obtained; and a transmitting unit that transmits the gateway ID of the selected gateway on the U plane to the second network.

[0012] Furthermore, a second aspect of the present invention is characterized in that, in the first aspect, the acquisition is performed using the IP address of the second network.

[0013] Furthermore, a third aspect of the present invention is characterized in that, in the second aspect, the network ID of the second network is obtained by referring to the correspondence between the IP address range and the network ID based on the IP address.

[0014] Furthermore, a fourth aspect of the present invention is characterized in that, in the second or third aspect, the IP address is a destination of a U-plane included in the signaling from the second network.

[0015] Furthermore, a fifth aspect of the present invention is characterized in that, in any of the first to fourth aspects, the gateway on the U plane is selected based on the network ID and the distance from the network having the network ID.

[0016] Furthermore, a sixth aspect of the present invention is characterized in that, in the fifth aspect, the distance is a distance on a network.

[0017] Furthermore, a seventh aspect of the present invention is characterized in that, in the fifth aspect, the distance is a geographical distance.

[0018] Furthermore, an eighth aspect of the present invention is characterized in that, in any of the fifth to seventh aspects, the gateway on the U-plane is selected by referring to a gateway table that maintains the association between a plurality of network IDs and one or more gateways on the U-plane associated with networks having each network ID.

[0019] Furthermore, a ninth aspect of the present invention is characterized in that, in any of the first to eighth aspects, the gateway on the U plane is selected based on the network ID and the identification number.

[0020] Furthermore, a tenth aspect of the present invention is characterized in that, in any of the first to ninth aspects, the gateway on the U-plane is composed of one or more instances on the cloud.

[0021] Furthermore, an eleventh aspect of the present invention is characterized in that, in the tenth aspect, the gateway on the U-plane does not perform functions on the C-plane when the wireless terminal accesses the network via the second network.

[0022] Furthermore, a twelfth aspect of the present invention is characterized in that, in any of the first to eleventh aspects, it is composed of one or more instances on the cloud.

[0023] Furthermore, a thirteenth aspect of the present invention is characterized in that, in any of the first to twelfth aspects, it does not perform functions on the U-plane when providing the wireless terminal with access to the network via the second network.

[0024] Furthermore, a fourteenth aspect of the present invention is characterized in that, in any of the first to thirteenth aspects, the first network is the network of a first MNO, and the second network is the network of a second MNO different from the first MNO.

[0025] Further, in a 15th aspect of the present invention, in the 14th aspect, one or more identification numbers are directly or indirectly stored in the wireless terminal, and the identification number used when the wireless terminal transmits a connection start request is for accessing the first network.

[0026] Further, in a 16th aspect of the present invention, in the 14th or 15th aspect, the identification number is an IMSI.

[0027] Further, in a 17th aspect of the present invention, in any one of the 14th to 16th aspects, the first network and the second network are interconnected.

[0028] Further, in an 18th aspect of the present invention, in any one of the 14th to 17th aspects, the first network is connected via an interconnection system.

[0029] Further, in a 19th aspect of the present invention, in any one of the 1st to 18th aspects, the transmission unit transmits a request for generating a tunnel endpoint to the selected gateway on the U plane.

[0030] Further, a 20th aspect of the present invention is a communication system for providing access to a network via a visiting gateway to a wireless terminal storing an identification number for accessing a home gateway, the communication system including: a receiving unit that receives a connection start request on a C plane from the wireless terminal; a selection unit that, in response to the connection start request, selects a gateway on a U plane to a network connected to the visiting gateway based on the obtained network ID of the visiting gateway; and a transmission unit that transmits the gateway ID of the selected gateway on the U plane to the visiting gateway.

[0031] Furthermore, a 21st aspect of the present invention is a communication method for providing access to a network via a second network to a wireless terminal that stores an identification number for accessing a first network, the method comprising: receiving a connection start request on the C plane from the wireless terminal; selecting a gateway on the U plane to the network connected to the second network based on the network ID of the second network obtained in response to the connection start request; and transmitting the gateway ID of the selected gateway on the U plane to the second network.

[0032] Furthermore, a 22nd aspect of the present invention is a program that causes a computer to execute a communication method for providing access to a network via a second network to a wireless terminal that stores an identification number for accessing a first network, wherein the communication method includes the steps of: receiving a connection start request on the C plane from the wireless terminal; selecting a gateway on the U plane to the network connected to the second network based on the network ID of the second network obtained in response to the connection start request; and transmitting the gateway ID of the selected gateway on the U plane to the second network.

[0033] Furthermore, a 23rd aspect of the present invention is a second network that communicates with a communication system for providing access to a network via a second network to a wireless terminal that stores an identification number for accessing a first network, the second network comprising: a receiving unit that receives a connection start request and APN on the C plane from the wireless terminal; and a transmitting unit that transmits the connection start request to the communication system instructed based on the APN, wherein the communication system, in response to the connection start request, receives a gateway ID of a gateway on the U plane to the network connected to the second network, selected based on the network ID of the second network, and establishes a communication path with the gateway on the U plane instructed by the gateway ID.

[0034] Furthermore, a 24th aspect of the present invention is a communication method for communicating with a communication system for providing access to a network via a second network to a wireless terminal that stores an identification number for accessing a first network, the method comprising: receiving a connection start request and APN on the C plane from the wireless terminal; transmitting the connection start request to the communication system indicated by an IP address determined by DNS based on the APN; receiving a gateway ID of a gateway on the U plane to the network connected to the second network, selected based on the network ID of the second network, in response to the connection start request in the communication system; and establishing a communication path between the communication system and the gateway on the U plane indicated by the gateway ID.

[0035] Furthermore, a 25th aspect of the present invention is a program for causing a computer to execute a communication method for communicating with a communication system for providing access to a network via a second network to a wireless terminal that stores an identification number for accessing a first network, wherein the communication method includes the steps of: receiving a connection start request and APN on the C plane from the wireless terminal; transmitting the connection start request to the communication system indicated by an IP address determined by DNS based on the APN; receiving a gateway ID of a gateway on the U plane to the network connected to the second network, selected by the communication system in response to the connection start request based on the network ID of the second network; and establishing a communication path with the gateway on the U plane indicated by the gateway ID. [Effects of the Invention]

[0036] According to one aspect of the present invention, delays caused by routing through the home location can be suppressed by selecting a gateway on the U-plane connected to a visiting gateway based on the network ID of the visiting gateway performing a function on the C-plane, and establishing a communication path between the two. [Brief explanation of the drawing]

[0037] [Figure 1] This diagram illustrates conventional international roaming. [Figure 2] This figure shows a communication network including a communication system according to one aspect of the present invention. [Figure 3] This figure shows the flow of signals within a communication network according to one aspect of the present invention. [Figure 4] This figure shows details of a communication system according to one aspect of the present invention. [Modes for carrying out the invention]

[0038] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0039] (Summary of the present invention) Figure 2 shows a communication network including a communication system according to one aspect of the present invention. For convenience, the first network 210 is a network of a European carrier whose service area is a predetermined region within Europe, and the second network 220 is a network of a Japanese carrier whose service area is a predetermined region within Japan. The SIM card inserted into the wireless terminal 100 is assumed to be contracted with the European carrier, as in Figure 1, and holds an identification number for accessing the European carrier.

[0040] Furthermore, it is possible for two or more IMSIs to be stored on the SIM card inserted into the wireless terminal 100. Moreover, it is possible for one or more IMSIs to be stored not only on the physical SIM card of the wireless terminal 100, but also on a semiconductor chip (also called an "eSIM") incorporated into the wireless terminal 100, or for one or more IMSIs to be stored on software installed in a secure area within the module of the wireless terminal 100. Thus, various forms are conceivable in which the wireless terminal 100 directly or indirectly holds an identification number.

[0041] Here, the communication system 200A is connected to the first network 210 either directly or via an inter-carrier interconnection network such as GRX. The communication system 200A, which provides wireless communication services to end users using the wireless communication infrastructure of the first network 210 (an MNO), is positioned as part of the network of a mobile virtual network operator (MVNO). As will be explained in more detail below, a wireless terminal 100 requesting access to a network 130 such as an IP network selects a third network 200B from among several networks to form a tunnel. This configuration is a novel idea that was only made possible by attempting to operate the communication system 200A and the third network 200B across national borders by the same operator.

[0042] In the following explanation, we will assume that the communication system 200A is a separate network from the first network 210. However, we would like to add that the spirit of the present invention is also applicable, for example, when the communication system 200A is constructed as part of the first network, on the same network as the first network.

[0043] First, the wireless terminal 100 sends a connection start request to the second network 220 in order to access the computer network 130 (S301). Upon receiving the connection start request, the second network 220 determines whether the carrier associated with the identification number, such as the IMSI included in the connection start request is the second network 220. If it is not the second network 220, i.e., if the second network 220 is a visiting gateway for the wireless terminal 100, it authenticates whether there is a contract between the first network 210 and the wireless terminal 100 (the SIM card inserted in it), and then queries the DNS, which holds the mapping between the APN and the gateway's IP address, based on the APN received from the wireless terminal 100 (S302). Based on the received APN, the DNS sends the IP address of the server to be accessed corresponding to the APN to the second network 220 (S303).

[0044] DNS can be part of communication system 200A, or it can be located in a location accessible from communication system 200A or the second network 220. Each APN does not necessarily correspond to a single IP address; multiple IP addresses can be associated, and when an APN is received, allocation can be performed using a round-robin method, selected according to an identification number such as IMSI, or selected according to the IP address of the second network 220 or the visiting gateway of the second network 220.

[0045] The second network 220 then transmits to the communication system 200A or a server within the communication system 200A, indicated by the IP address corresponding to the APN, the connection initiation request (in this specification, “connection initiation request” also includes requests transmitted by the second network 220 that substantially correspond to the connection initiation request received by the second network 220), the identification number included in the connection initiation request, and the IP address of the second network 220 or the visiting gateway of the second network 220 (S304). The signaling on the C plane transmitted from the second network 220 includes the IP address of the second network 220 or the visiting gateway of the second network 220 as the destination on the U plane, and this IP address can be used. This IP address may also be considered as part of the connection initiation request.

[0046] The second network 220 may, in addition to the IP address, further transmit to the communication system 200A auxiliary information that helps the wireless terminal 100 in the communication system 200A select a gateway or a third network 200B that includes such a gateway for establishing a connection.

[0047] In the communication system 200A, the network ID of a second network 220 can be obtained or inferred from the IP address of the second network 220, based on the IP address of the second network 220 that has been obtained or received. Here, the IP address range table can be stored in the storage unit of the communication system 200A or in a storage device or storage medium accessible to the communication system 200A. Alternatively, inference can be made by reverse lookup, which converts an IP address to a domain name, or by whois query, which provides registrant information for a domain associated with an IP address.

[0048] In the communication system 200A, a gateway table is stored that holds the correspondence between a network ID and the associated gateway on the U-plane of the network having that network ID. Based on the acquired network ID, the wireless terminal 100 can select a gateway or a third network 200B containing it for establishing a connection. In addition, the communication system 200A may, if necessary, request the selected third network 200B or its gateway to generate a tunnel endpoint (TE) ID in response to a received connection initiation request (S305).

[0049] The communication system 200A receives the tunnel endpoint ID (TEID) from the third network 200B (S306) and transmits it to the second network 220 along with the gateway ID (S307). The gateway ID is, for example, the IP address of the gateway on the selected U-plane. If the gateway of the third network 200B has two or more servers that can connect to the second network 220, one of the IP addresses of those servers is selected as the gateway ID.

[0050] Upon receiving the gateway ID and TEID, the second network 220 forms a tunnel between its visiting gateway and the gateway of the third network 200B indicated by the gateway ID (S308).

[0051] In conventional international roaming, it is always necessary to return to the first network 210, which is the home carrier, to communicate, causing delays. However, according to the present invention, the wireless terminal 100 can form a U-plane tunnel with the gateway of the third network 200B associated with the second network 220, which is the visiting carrier, and can shortcut the home location, thereby significantly improving latency.

[0052] Examples of networks accessed by the wireless terminal 100 include not only IP networks such as the Internet, but also non-IP networks. In addition to public systems, private systems are also included. Private systems include on-premises private systems, and when at least a part of the third network 200B is implemented on the cloud, different IP networks on the same cloud or IP networks on different clouds are included, and the third network 200B and these private systems can be connected by dedicated lines or virtual dedicated lines.

[0053] Furthermore, please note that unless the word "only" is used, such as in "based only," "according only," or "in the case only," it is naturally assumed in this specification that additional information may also be considered.

[0054] (Details of the communication system) Figure 4 shows details of a server in a communication system according to one embodiment of the present invention. Each of the one or more servers 400 in the communication system 200A may be a server comprising a communication unit 401 such as a communication interface that receives connection start requests on the C plane from a wireless terminal 100, and a processing unit 403 such as a processor or CPU that, in response to the connection start request, selects a gateway to the computer network 130 connected to the second network 220 by referring to the gateway table stored in a storage unit 402 including a memory, hard disk, or other storage device or storage medium, based on the network ID of the second network 220 that has been acquired. The communication unit 401 transmits the gateway ID of the selected gateway to the second network 220. If the communication unit 401 has received the ID of a tunnel endpoint generated by the selected gateway, it also transmits this to the second network 220.

[0055] The server is not limited to a single physical server, but can consist of multiple accessible servers, and the storage unit 402 may be a storage device accessible from the server over a computer network. Furthermore, the operation of one or both of the communication unit 401 and the processing unit 403 can be achieved by executing one or more programs that cause a computer to perform the operation, and these programs can be recorded on a computer-readable storage medium to become a non-transient program product.

[0056] Server 400 can be an instance on a public or private cloud. Here, "cloud" in this specification means a system that can dynamically provision and provide computing resources such as CPU, memory, storage, and network bandwidth on a network as needed. For example, a cloud can be used through AWS, etc.

[0057] The communication system 200A may perform functions on the C-plane when initiating a connection to provide the wireless terminal 100 with access to the network 130 via the second network 220, but may not perform functions on the U-plane. Functions on the U-plane can be performed in a third network 200B whose service area is outside the service area of ​​one or both of the first network 210 and the communication system 200A, such as overseas. When the third network 200B is outside the service area of ​​the communication system 200A, it does not necessarily mean overseas. The third network 200B may perform functions on the U-plane when providing the wireless terminal 100 with access to the computer network 130 via the second network 220, but may not perform functions on the C-plane.

[0058] (Gateway table details) The gateway table maintained or accessible by the communication system 200A defines the correspondence between a network ID and a gateway or server associated with the network having that network ID, or the network containing such gateway or server.

[0059] In one embodiment, the gateway table defines the correspondence between a network ID and one or more gateways located near a network or its gateways, among the networks or gateways scattered in various locations, that possess the network ID (i.e., the second network 220), or the network containing such gateways (i.e., the third network 200B). Here, the "distance" to the gateway can be the distance on the network measured by the delay time. The distance on the network can be calculated, for example, by the number of hops. Alternatively, gateways can be arranged in order of proximity, starting with those closest geographically.

[0060] In another embodiment, a network ID may be associated with one or more gateways or networks containing such gateways that are outside the service area of ​​the network having the network ID (i.e., the second network 220).

[0061] Furthermore, for example, multiple gateways or networks containing them can be associated with a single network ID, and which gateway to match can be determined based on an identification number such as IMSI included in the connection initiation request. A specific identification number can be associated with a gateway or network containing it that offers a specific service on the U-plane, regardless of distance, and as an example, a gateway on the U-plane can be selected solely by its identification number.

[0062] Furthermore, the communication system 200A or a server accessible from it may monitor the processing capacity metrics of each of the multiple U-plane gateways associated with the second network 220 and select the gateway with the lower processing load. Examples of metrics to monitor include CPU load, memory utilization, disk reads, disk writes, network traffic received, and network traffic transmitted. The one or more servers associated with each gateway to the second network 220 can be instances on a public or private cloud. In the distance-based selection of gateways on the U-plane described above, it is also beneficial to ultimately select the one with the lower processing load when multiple equivalent gateways exist.

[0063] In another embodiment, the communication system 200A may receive the above-mentioned auxiliary information from the second network 220. Specifically, there may be one or more servers that serve as the exit point for the connection between the second network 220 and the third network, and the IP addresses of each server may be received as auxiliary information. In this case, the communication system 200A may select the destination gateway or the third network 200B that includes it, based on each server, and select the combination that has the shortest distance between the second network 220 and the third network 200B.

[0064] (Details of the second network) The second network 220, like the communication system 200A, has one or more servers, each server comprising a communication unit such as a communication interface, a storage unit including a storage device or storage medium such as memory or a hard disk, and a processing unit such as a processor or CPU. The communication unit performs the transmission and / or reception of the aforementioned data, and the processing unit performs the necessary processing. The storage unit may be a storage device accessible from the server over the computer network. Furthermore, the operation of one or both of the communication unit and the processing unit can be realized by executing one or more programs that cause a computer to perform such operations. These programs can be recorded on a computer-readable storage medium to become non-transient program products. In addition, the one or more servers of the second network 220 can be instances on a public cloud or a private cloud. [Explanation of symbols]

[0065] 100 wireless terminals 110 European Carriers 120 Japan Carrier 130 IP Networks 200A Communication System 200B Third Network 210 The first network 220 Second Network 400 servers 401 Communications Department 402 Storage section 403 Processing Unit

Claims

1. A communication method for providing access to a network other than the first network, via a second network which is a visiting carrier, to a wireless terminal that stores an identification number for accessing the first network, wherein a computer connected to the first network The steps include receiving from the second network a second connection start request corresponding to the first connection start request transmitted by the wireless terminal to the second network, and the IP address of the second network or its visiting gateway, In response to the second connection initiation request, the step of selecting a gateway on the U-plane to the second network that is connected to the second network and is outside the coverage area of ​​the first network, The steps include: transmitting the gateway ID of the selected gateway on the U plane toward the second network; Includes, The gateway on the U-plane is selected based on the IP address such that the network distance or geographical distance between the second network and the network is the shortest.

2. A communication method according to claim 1, The gateway on the U-plane is one or more instances on the cloud.

3. A communication method according to Claim 1, The selection is made by monitoring the metrics of each of the multiple gateways on the U-plane and selecting the gateway with the lower processing load, when there are multiple gateways on the U-plane that are of equivalent distance on the network or geographical distance.

4. A communication method for providing a wireless terminal, which stores an identification number for accessing a first network in a computer, with access to a network other than the first network via a second network that is a visiting carrier, and a program for causing a computer to execute the communication method described in claim 1.

5. A communication system for providing a wireless terminal, which stores an identification number for accessing a first network, with access to a network other than the first network via a second network that is a visiting carrier, The second network receives a second connection start request corresponding to the first connection start request transmitted by the wireless terminal to the second network, and the IP address of the second network or its visiting gateway. In response to the second connection initiation request, a gateway on the U-plane to the second network, which is outside the range of the first network, is selected to connect to the second network. The gateway ID of the selected gateway on the U plane is transmitted to the second network. The gateway on the U-plane is configured to be selected based on the IP address such that the network distance or geographical distance between the second network and the network is the shortest.

6. The communication system according to claim 5, The selection is configured to be made by monitoring the metrics of each of the multiple gateways on the U-plane and selecting the gateway with the lower processing load when there are multiple gateways on the U-plane with equivalent distance on the network or geographical distance.

7. The first network and, The communication system described in claim 5 and A communication network equipped with [the necessary components / features].

8. The second network is a visiting carrier, The communication system described in claim 5 and A communication network equipped with [the necessary components / features].

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