JP5402540B2 - Communication system and relay control method - Google Patents

Description

  The present invention relates to a communication system and a relay control method for relaying communication using hierarchical nodes.

  In recent years, in mobile communications, in order to be able to receive services provided by mobile communications operators even in dead zones such as homes and underground where radio waves from normal base stations do not reach, ultra-small base stations The femtocell base station is being installed in the dead zone. The femtocell base station is connected to a broadband line laid in a home or underground, and is connected to a network of a mobile communication carrier via the broadband line and the Internet. The broadband line is, for example, an optical line or a cable TV line.

  In addition, a normal base station is a base station which is installed on the roof of a building or the like and has a radius of several hundred meters to several tens of kilometers, which is a range in which communication with the base station is possible. On the other hand, the cell of the femtocell base station has a radius of about several tens of meters, which is a very narrow range compared to a normal base station.

  Even when communication is performed via a femtocell base station, a portable terminal that performs communication via a normal base station can be used as it is. In addition, since the number of mobile terminals that can be connected to one femtocell base station is very small, one mobile terminal can occupy one femtocell base station, and high-speed communication is possible. realizable.

  Femtocell base stations are assumed to be installed in various facilities such as households, and with the spread of femtocell base stations, traffic on the network of broadband lines, the Internet, and mobile operators increases. It is expected that. Hereinafter, the term “network” refers to each or all of the broadband line, the Internet, and the network of the mobile communication carrier.

  In recent years, home appliances including personal computers, televisions, game machines and the like have been connected to the network, and traffic on the network has increased.

  In this way, traffic on the network is expected to increase steadily, and there is a concern that the communication quality of communication via the femtocell base station will deteriorate. Further, a provider providing a network is required to reinforce facilities constituting the network in order to cope with increasing traffic. Along with this, the operating cost of the equipment is expected to increase.

  By the way, in communication via a femtocell base station, even when a call is made between portable terminals existing in a cell of the same femtocell base station, user data (voice packet) is transmitted between the portable terminals via the network. Sent and received. Therefore, the user pays a communication fee to a telecommunications carrier, an Internet provider, a mobile telecommunications carrier, etc. that provides a broadband line, even though communication is performed between adjacent mobile terminals via the same femtocell base station. Must-have.

  Here, for example, Patent Literature 1 discloses a technology that enables reduction of traffic on a network and reduction of communication charges paid by a user.

  In the technique disclosed in Patent Document 1, a wireless base station (wireless device) connected to a private branch exchange (IP-PBX) capable of controlling communication closed in a building, and a network of a mobile communication carrier And a wireless base station (wireless device) connected to. Then, the terminal (communication device) performs call control by selecting one of the radio base stations (radio devices) according to the type of communication.

  By using the technique disclosed in Patent Document 1, in the case of communication between terminals existing in a range where radio waves from a wireless base station connected to a private branch exchange reach, it is possible not to go through the network. it can. Thereby, it is possible to reduce the traffic on the network and reduce the communication fee paid by the user.

JP 2009-105937 A

  However, when the technique disclosed in Patent Document 1 described above is used, there is a problem that a private branch exchange must be provided.

  An object of the present invention is to provide a communication system and a relay control method capable of realizing a reduction in traffic on a network and a reduction in a communication fee paid by a user without providing a private branch exchange.

In order to achieve the above object, a communication system of the present invention has a plurality of nodes that are layered and connected to nodes in adjacent layers, and a plurality of terminals, and among the plurality of nodes that are layered There is a plurality of lowest-layer nodes, each of the plurality of terminals is connected to one of the plurality of lowest-layer nodes, and the communication system relays communication between the plurality of terminals using the nodes. ,
A relay node that relays the communication among the plurality of hierarchized nodes is determined according to each of the lowest-layer nodes to which the plurality of terminals performing communication are connected.

In order to achieve the above object, the relay control method of the present invention includes a plurality of nodes that are hierarchized and connected to nodes in adjacent hierarchies, and a plurality of terminals, and A communication system in which a plurality of lowermost nodes among nodes exist, each of the plurality of terminals is connected to one of the plurality of lowermost nodes, and communication between the plurality of terminals is relayed using the nodes The relay control method in
In accordance with each of the lowest-layer nodes to which the plurality of terminals that perform communication are connected, a relay node determination process that determines a relay node that relays the communication among the plurality of hierarchical nodes.

  In the communication system of the present invention, a relay node that relays the communication is determined among the plurality of hierarchized nodes according to each of the lowest-layer nodes to which a plurality of terminals that perform communication are connected.

  As a result, communication via the network can be minimized. Therefore, it is possible to reduce the traffic on the network and the communication fee paid by the user without providing a private branch exchange.

It is a block diagram which shows the structure of one Embodiment of the communication system of this invention. It is a block diagram which shows an example of a structure of each apparatus with which the communication system shown in FIG. 1 is provided, (a) is a block diagram which shows an example of a structure of a terminal, (b) shows an example of a structure of a femtocell base station. A block diagram and (c) are block diagrams showing an example of a configuration of a gateway. It is a block diagram which shows an example of a structure of each apparatus with which the communication system shown in FIG. 1 is provided, (a) is a block diagram which shows an example of a structure of a mobile switching unit, (b) is an example of a structure of a subscriber management server. FIG. It is a figure which shows an example of the structure of the table which the database shown in FIG.3 (b) has, (a) is a figure which shows an example of a structure of a subscriber information table, (b) is an example of the structure of a group information table. FIG. FIG. 5 is a sequence diagram for explaining an operation when a terminal moves into a cell of a femtocell base station in the communication system shown in FIGS. FIG. 5 is a sequence diagram for explaining an operation when extension communication is performed in the communication system shown in FIGS. 1 to 4. FIG. 5 is a sequence diagram for explaining an operation when extension communication is performed in the communication system shown in FIGS. 1 to 4. 5 is a flowchart for explaining an operation in which a mobile switching device determines a relay node in the communication system shown in FIGS. It is a block diagram which shows the structure of other embodiment of the communication system of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an embodiment of a communication system according to the present invention.

  As shown in FIG. 1, the communication system of this embodiment includes terminals 100-1 to 100-n and 200-1 to 200-n, femtocell base stations 10 and 20, which are a plurality of hierarchized nodes, and a gateway. 40, a mobile switching device 50, and a subscriber management server 60. In the present embodiment, among the terminals 100-1 to 100-n and 200-1 to 200-n, communication between a caller terminal that is a caller of communication and a callee terminal that is a callee is a node. Relay using. Of the plurality of hierarchized nodes, the mobile switch 50 is the uppermost node, and the femtocell base stations 10 and 20 are the lowermost nodes.

  In the figure, the network above the gateway 40 is a network of a mobile communication carrier. The femtocell base stations 10 and 20 are connected to a broadband line provided by a communication carrier, and are further connected to a gateway 40 via the Internet 30.

  In the present embodiment, the terminals 100-1 to 100-n exist in the cell of the femtocell base station 10. Then, the terminals 100-1 to 100-n receive position information which is transmitted from the femtocell base station 10 and is information for identifying the femtocell base station 10. That is, the terminals 100-1 to 100-n are connected to the femtocell base station 10 by radio when present in the cell of the femtocell base station 10. Similarly, the terminals 200-1 to 200-n are connected to the femtocell base station 20 by radio.

  Further, in this embodiment, in order to make the explanation easy to understand, a case where there are two femtocell base stations will be described, but the number of femtocell base stations is not limited to two.

  2 is a block diagram showing an example of the configuration of each device included in the communication system shown in FIG. 1, (a) is a block diagram showing an example of the configuration of terminal 100-1, and (b) is a femtocell base. 2 is a block diagram showing an example of the configuration of the station 10, and FIG. The terminals 100-2 to 100-n and 200-1 to 200-n have the same configuration as the terminal 100-1, and the femtocell base station 20 has the same configuration as the femtocell base station 10.

  3 is a block diagram illustrating an example of the configuration of each device included in the communication system illustrated in FIG. 1, as in FIG. 2, and FIG. 3A is a block diagram illustrating an example of the configuration of the mobile switching device 50. (B) is a block diagram showing an example of the configuration of the subscriber management server 60.

  First, referring to FIG. 2A, the terminal 100-1 includes an air IF (InterFace) unit 101, a storage unit 102, and a call processing unit 103.

  The air IF unit 101 mediates wireless communication between the terminal 100-1 and the femtocell base station 10.

  The storage unit 102 stores in advance a terminal ID (IDentification) that identifies the terminal 100-1 and an external line number that is a terminal number in the second format that identifies the terminal 100-1 when performing communication. Further, in accordance with an instruction from the call processing unit 103, an extension number that is a terminal number in the first format for identifying the terminal 100-1 when performing communication is stored. In addition, the number of digits of a number differs between an outside line number and an extension number, for example. That is, the format differs between the outside line number and the extension number.

  The call processing unit 103 performs call processing related to outgoing and incoming calls. Specifically, when the call processing unit 103 receives the position information transmitted from the femtocell base station 10, the call processing unit 103 sends a position registration request including the received position information and the terminal ID stored in the storage unit 102 to the femtocell. It transmits to the mobile switching device 50 via the base station 10. Further, the call processing unit 103 receives a location registration response that is a response to the location registration request transmitted from the mobile switching device 50, and stores the extension number indicated by the extension number information included in the received location registration response in the storage unit 102. Remember. This extension number is an extension number given to the terminal 100-1. Further, when the terminal 100-1 starts communication as a caller terminal, the call processing unit 103 receives an input of the terminal number of the callee terminal of the communication from the user. A user is a subscriber of a mobile communication carrier. Further, the terminal number received from the user is an outside line number or an extension number. Hereinafter, communication using an extension number is referred to as extension communication. Then, the call processing unit 103 transmits a call request including the terminal ID stored in the storage unit 102 and the received terminal number to the mobile switch 50 via the femtocell base station 10.

  Next, referring to FIG. 2 (b), the femtocell base station 10 includes an air IF unit 11, a gateway IF unit 12, a call processing unit 13, and a data control unit 14.

  The air IF unit 11 mediates wireless communication between the femtocell base station 10 and the terminals 100-1 to 100-n.

  The gateway IF unit 12 mediates communication between the femtocell base station 10 and the gateway 40.

  The call processing unit 13 performs call processing among the terminals 100-1 to 100-n, the gateway 40, and the mobile switching device 50. Specifically, the call processing unit 13 transmits position information for identifying the femtocell base station 10 to terminals existing in the cell of the femtocell base station 10. In addition, the call processing unit 13 receives a location registration request, a transmission request, and the like transmitted from the terminals 100-1 to 100-n and transmits them to the gateway 40. Further, the call processing unit 13 transmits the location registration response and the like transmitted from the gateway 40 to the corresponding terminals 100-1 to 100-n. Further, the call processing unit 13 receives the route control request transmitted from the mobile switch 50. The route control request is transmitted to a node determined as a relay node that relays communication between the originating terminal and the terminating terminal. The route control request includes, for example, information related to the relay node facing the node in the communication.

  The data control unit 14 receives user data transmitted from the terminals 100-1 to 100-n and the gateway 40. Then, the received user data is transferred to the terminals 100-1 to 100-n and the gateway 40 according to the information included in the route control request received by the call processing unit 13. Specifically, for example, the data control unit 14 specifies a port number included in the route control request, and receives from the terminals 100-1 to 100-n to a gateway having an IP (Internet Protocol) address included in the route control request. User data transferred.

  Next, referring to FIG. 2 (c), the gateway 40 includes a femtocell base station IF unit 41, a mobile switching device IF unit 42, a call processing unit 43, and a data control unit 44.

  The femtocell base station IF unit 41 mediates communication between the gateway 40 and the femtocell base stations 10 and 20.

  The mobile switching device IF unit 42 mediates communication between the gateway 40 and the mobile switching device 50.

  The call processing unit 43 performs call processing between the femtocell base stations 10 and 20 and the mobile switch 50. Specifically, the call processing unit 43 receives a location registration request, a transmission request, and the like transmitted from the femtocell base stations 10 and 20 and transmits them to the mobile switch 50. Further, the call processing unit 43 receives the location registration response transmitted from the mobile switch 50 and transmits it to the femtocell base stations 10 and 20. In addition, the call processing unit 43 receives the route control request transmitted from the mobile switch 50.

  The data control unit 44 receives user data transmitted from the femtocell base stations 10 and 20, the mobile switching device 50, and another gateway (not shown). Then, the received user data is transferred to the femtocell base stations 10 and 20, the mobile switch 50, and other gateways according to the information included in the route control request received by the call processing unit 43. Specifically, for example, the data control unit 44 designates the port number included in the route control request, and transfers the received user data to the femtocell base station of the IP (Internet Protocol) address included in the route control request. .

  Next, referring to FIG. 3A, the mobile switching device 50 includes a gateway IF unit 51, a subscriber management server IF unit 52, a call processing unit 53, and an extension control unit 54.

  The gateway IF unit 51 mediates communication between the mobile switching device 50 and the gateway 40.

  The subscriber management server IF unit 52 mediates communication between the mobile switch 50 and the subscriber management server 60.

  The call processing unit 53 performs call processing among the femtocell base stations 10 and 20, the gateway 40, and the subscriber management server 60. Specifically, the call processing unit 53 receives the location registration request transmitted from the gateway 40. Then, an update request for updating the position information of the terminal identified by the terminal ID, including the position information and the terminal ID included in the received position registration request, is transmitted to the subscriber management server 60. The call processing unit 53 receives extension number information that is transmitted from the subscriber management server 60 and is a response to the update request. Then, a location registration response including the received extension number information and a response to the location registration request is transmitted to the gateway 40. Further, the call processing unit 53 receives a call request transmitted from the gateway 40.

  The extension control unit 54 includes a terminal ID and a terminal number included in the outgoing call request received by the call processing unit 53, and issues an information acquisition request for acquiring information stored in the subscriber management server 60 to the subscriber management. Send to server 60. Further, the extension control unit 54 receives an information acquisition response that is transmitted from the subscriber management server 60 and is a response to the information acquisition request. And based on the information contained in the received information acquisition response, the relay node which relays communication between a transmission side terminal and a receiving side terminal is determined. The operation for determining a relay node will be described in detail in the operation flow described later. Further, the extension control unit 54 transmits a route control request to the relay node.

  Finally, referring to FIG. 3 (b), the subscriber management server 60 includes a mobile switching unit IF unit 61, a control unit 62, and a database 63.

  The mobile switching device IF unit 61 mediates communication between the subscriber management server 60 and the mobile switching device 50.

  The database 63 has a subscriber information table in which terminal IDs of all subscribers of mobile communication carriers are associated with external line numbers, extension numbers, and position information. The database 63 has a group information table in which position information for identifying femtocell base stations is grouped.

  4 is a diagram illustrating an example of a configuration of a table included in the database 63 illustrated in FIG. 3B. FIG. 4A is a diagram illustrating an example of a configuration of a subscriber information table, and FIG. 4B is a group information table. It is a figure which shows an example of a structure of.

  In the table illustrated in FIG. 4, for example, “A” is position information for identifying the femtocell base station 10, and “B” is position information for identifying the femtocell base station 20. In this case, the position information “A” and “B” belong to the same group 1 as shown in FIG. That is, the femtocell base stations 10 and 20 connected to the gateway 40 belong to the same group.

  Referring to FIG. 3B again, the control unit 62 receives the update request transmitted from the mobile switching device 50. Then, in the subscriber information table of the database 63, the position information corresponding to the terminal ID included in the received update request is updated with the position information included in the received update request. Then, the extension number associated with the terminal ID included in the received update request is acquired from the subscriber information table, and extension number information indicating the acquired extension number is transmitted to the mobile switch 50. Here, the extension number is determined in advance, but a random number that does not overlap with the extension number of another terminal may be generated as the extension number. Further, the control unit 62 receives the information acquisition request transmitted from the mobile switching device 50. Then, information corresponding to the terminal ID and terminal number included in the received information acquisition request is acquired from the subscriber information table and group information table of the database 63. Then, the control unit 62 transmits an information acquisition response including information acquired from the database 63 to the mobile switching device 50.

  The operation of the communication system configured as described above will be described below.

  First, an operation when the terminal 100-1 shown in FIG. 1 has moved into the cell of the femtocell base station 10 will be described.

  FIG. 5 is a sequence diagram for explaining the operation when the terminal 100-1 moves into the cell of the femtocell base station 10 in the communication system shown in FIGS.

  First, when the terminal 100-1 moves into the cell of the femtocell base station 10, the call processing unit 103 of the terminal 100-1 is transmitted from the femtocell base station 10 and identifies the femtocell base station 10. The position information 201 is received.

  Next, the call processing unit 103 transmits a location registration request 202 including the received location information 201 and the terminal ID stored in the storage unit 102 to the mobile switching device 50 via the femtocell base station 10.

  The call processing unit 53 of the mobile switch 50 that has received the location registration request 202 transmitted from the terminal 100-1 sends the update request 203 including the location information and the terminal ID included in the received location registration request 202 to the subscriber management server. 60.

  The control unit 62 of the subscriber management server 60 receives the update request 203 transmitted from the mobile switch 50. Then, the control unit 62 uses the subscriber information table of the database 63 to obtain the location information of the terminal 100-1 associated with the terminal ID included in the received update request 203, and the femto included in the received update request 203. It is updated with position information for identifying the cell base station 10.

  In addition, the control unit 62 acquires the extension number associated with the terminal ID included in the received update request 203 from the subscriber information table, and transmits the extension number information 204 indicating the acquired extension number to the mobile switch 50. To do.

  Receiving the extension number information transmitted from the subscriber management server 60, the call processing unit 53 of the mobile switch 50 transmits a location registration response 205 including the received extension number information to the terminal 100-1.

  The call processing unit 103 of the terminal 100-1 that has received the location registration response 205 transmitted from the mobile switching device 50 via the femtocell base station 10 receives the extension number indicated by the extension number information included in the received location registration response 205. Is stored in the storage unit 102.

  Next, an operation when communication is performed in the communication system shown in FIGS. 1 to 4 will be described.

  FIG. 6 is a sequence diagram for explaining an operation when extension communication is performed in the communication system shown in FIGS. FIG. 6 shows an operation in extension communication from the terminal 100-1 existing in the cell of the femtocell base station 10 to the terminal 100-2 existing in the cell of the same femtocell base station 10. That is, the terminal 100-1 is a caller terminal, and the terminal 100-2 is a callee terminal.

  FIG. 7 is a sequence diagram for explaining the operation when extension communication is performed in the communication system shown in FIGS. FIG. 7 shows an operation in extension communication from the terminal 100-1 existing in the cell of the femtocell base station 10 to the terminal 200-1 existing in the cell of the femtocell base station 20. That is, the terminal 100-1 is a caller terminal, and the terminal 200-1 is a callee terminal. Further, it is assumed that the position information for identifying the femtocell base station 10 and the position information for identifying the femtocell base station 20 belong to the same group in the group information table that the database 63 has.

  FIG. 8 is a flowchart for explaining an operation in which the mobile switch 50 determines a relay node in the communication system shown in FIGS.

  First, the call processing unit 103 of the terminal 100-1 receives an input of the terminal number of the receiving terminal from the user.

  Next, the call processing unit 103 transmits a call request 301 including the terminal ID stored in the storage unit 102 and the received terminal number to the mobile switching device 50 via the femtocell base station 10.

  The call processing unit 53 of the mobile switching device 50 receives the call request 301 transmitted from the terminal 100-1 (Step S1).

  Next, the extension control unit 54 of the mobile switch 50 transmits an information acquisition request 302 including a terminal ID and a terminal number included in the call request received by the call processing unit 53 to the subscriber management server 60.

  The control unit 62 of the subscriber management server 60 that has received the information acquisition request 302 transmitted from the mobile switching device 50 has information corresponding to the terminal ID and terminal number included in the received information acquisition request 302 in the database 63. Obtained from the subscriber information table and group information table. In the case of the operation illustrated in FIG. 6, information regarding the terminal 100-1 and the terminal 100-2 is acquired. On the other hand, in the case of the operation illustrated in FIG. 7, information regarding the terminal 100-1 and the terminal 200-1 is acquired.

  Then, the control unit 62 transmits an information acquisition response 303 including the acquired information to the mobile switching device 50.

  The extension control unit 54 of the mobile switching center 50 receives the information acquisition response 303 transmitted from the subscriber management server 60 (step S2).

  Next, the extension control unit 54 confirms the format of the terminal number included in the call request received in step S1 (step S3).

  As a result of the confirmation in step S3, if the terminal number format is an external line number format, the extension control unit 54 notifies the call processing unit 53 to that effect. Then, the call processing unit 53 that has received the notification performs connection using the outside line number (step S4).

  On the other hand, as a result of the confirmation in step S3, if the terminal number format is the extension number format, the extension control unit 54 is included in the received call request based on the information included in the received information acquisition response 303. The position information associated with the terminal number is compared with the position information associated with the terminal ID included in the received call request (step S5).

  If the two pieces of position information match as a result of the comparison in step S5, the extension control unit 54 of the mobile switching device 50 transmits a route control request 306 to the femtocell base station 10 as shown in FIG. 6 (step S6). .

  Note that the route control request 306 transmitted to the femtocell base station 10 includes an instruction to return user data in communication between the terminal 100-1 and the terminal 100-2 at the femtocell base station 10. Thereby, the femtocell base station 10 becomes a relay node, and user data is not transmitted to the gateway 40 and the mobile switch 50. Further, the femtocell base station 10 that has received the route control request 306 transmitted from the mobile switch 50 sends a route control response 307 indicating that the route control request 306 has been received to the mobile switch 50 as shown in FIG. Send.

  On the other hand, if the two pieces of position information do not match as a result of the comparison in step S5, the extension control unit 54 determines whether the two pieces of position information belong to the same group from the information included in the received information acquisition response 303. Confirm (step S7).

  As a result of the confirmation in step S7, when the two pieces of position information belong to the same group, the extension control unit 54 of the mobile switch 50 sends a route control request 308 to the femtocell base station 10 as shown in FIG. The route control request 309 is transmitted to the femtocell base station 20. Further, the extension control unit 54 transmits a route control request 310 to the gateway 40 (step S8).

  Note that the route control requests 308 and 309 transmitted to the femtocell base stations 10 and 20 include the IP address and port number of the gateway 40. Further, the route control request 310 transmitted to the gateway 40 includes the IP addresses and port numbers of the femtocell base stations 10 and 20. Thereby, the communication path | route of the femtocell base station 10-the gateway 40-the femtocell base station 20 is set. That is, the femtocell base stations 10 and 20 and the gateway 40 serve as relay nodes, and no user data is transmitted to the mobile switch 50.

  In addition, the femtocell base stations 10 and 20 and the gateway 40 that have received the route control requests 308 to 310 transmitted from the mobile switch 50 indicate that the route control requests 308 to 310 have been received, as shown in FIG. Control responses 311 to 313 are transmitted to the mobile switching device 50.

  On the other hand, as a result of the confirmation in step S7, if the two pieces of position information do not belong to the same group, the extension control unit 54 notifies the call processing unit 53 to that effect. The call processing unit 53 that has received the notification performs a disconnection process (step S9).

  Before the route control requests 306 and 308 to 310 are transmitted, the call signal 304 is transmitted from the call processing unit 53 of the mobile switch 50 to the receiving terminal. In the case of the operation shown in FIG. 6, the calling signal 304 is transmitted to the terminal 100-2 that is the receiving terminal, and in the case of the operation shown in FIG. 7, the calling signal 304 is sent to the terminal 200 that is the receiving terminal. -1. Then, when the mobile switch 50 receives the call response signal 305 transmitted from the called terminal, the user data is relayed by the relay node as described above.

  As described above, in the communication system according to the present embodiment, a relay node that relays communication is determined from a plurality of hierarchized nodes according to each femtocell base station to which a terminal that performs communication is connected. .

  As a result, communication via the network can be minimized. Therefore, it is possible to reduce the traffic on the network and the communication fee paid by the user without providing a private branch exchange.

  In addition, the users of the terminals 100-1 to 100-n and 200-1 to 200-n recognize whether it is extension communication or extension communication using the extension number by using the extension number or the extension number. Can communicate. In the case of extension communication, the user can communicate without worrying about communication charges.

  Further, by reducing the traffic on the network, it is possible to contribute to improving the communication quality of communication via the femtocell base station.

  In the present embodiment, the case where there is one gateway has been described, but the number of gateways is not limited to one.

  FIG. 9 is a block diagram showing the configuration of another embodiment of the communication system of the present invention.

  The communication system shown in FIG. 9 includes two gateways 40-1 and 40-2. The femtocell base station 10 and the femtocell base station 20 are connected to different gateways.

  Even in such a configuration, the femtocell base station 10 connected to the gateway 40-1 and the femtocell base station 20 connected to the gateway 40-2 are grouped in the same group as described above. It is possible to perform extension communication that is not relayed by the mobile switching device 50. Specifically, this can be realized by the mobile switching device 50 transmitting a route control request to the gateways 40-1 and 40-2 and the femtocell base stations 10 and 20.

  In this case, the route control request transmitted to the gateway 40-1 includes the IP addresses of the femtocell base station 10 and the gateway 40-2. Further, the route control request transmitted to the gateway 40-2 includes the IP addresses of the femtocell base station 20 and the gateway 40-1. The route control request transmitted to the femtocell base station 10 includes the IP address of the gateway 40-1, and the route control request transmitted to the femtocell base station 20 includes the IP of the gateway 40-2. Address etc. are included. As a result, the communication paths of the femtocell base station 10 to the gateway 40-1 to the gateway 40-2 to the femtocell base station 20 are set.

  Moreover, the extension number given to a terminal does not necessarily need to be associated with the terminal ID on a one-to-one basis, and may be given randomly within the same group. By giving a random extension number, extension communication is performed between a visitor's terminal such as a public facility and a telephone (a terminal existing in the cell of the femtocell base station) installed in the public facility. It becomes possible.

  Further, the extension number given to one terminal is not limited to one, and a plurality of extension numbers may be given.

10, 20 Femtocell base station 11, 101 Air IF unit 12, 51 Gateway IF unit 13, 43, 53, 103 Call processing unit 14, 44 Data control unit 30 Internet 40, 40-1, 40-2 Gateway 41 Femtocell Base station IF unit 42, 61 Mobile switching unit IF unit 50 Mobile switching unit 52 Subscriber management server IF unit 54 Extension control unit 54
60 subscriber management server 62 control unit 63 database 100-1 to 100-n, 200-1 to 200-n terminal 102 storage unit 201 location information 202 location registration request 203 update request 204 extension number information 205 location registration response 301 outgoing request 302 Information acquisition request 303 Information acquisition response 304 Call signal 305 Call response signal 306, 308 to 310 Route control request 307, 311 to 313 Route control response

Claims (4)

There are a plurality of nodes that are hierarchized and connected to nodes in adjacent hierarchies, and a plurality of terminals, and there are a plurality of lowermost nodes among the plurality of hierarchized nodes, and Each of the plurality of hierarchized nodes corresponding to each of the lowest layer nodes to which the plurality of terminals that are connected are connected to any of the plurality of lowest layer nodes and perform communication. It was determined relay node for relaying a communication between the plurality of terminals a communication system for relaying using a node that the determined,
A terminal ID for identifying each of the plurality of terminals, position information for identifying the lowest layer node to which each of the plurality of terminals is connected, and a first identification for identifying each of the plurality of terminals when performing communication. A server that stores group information in which the location information is grouped, and stores the subscriber information in association with the terminal numbers of the first and second formats.
The originating terminal that is the originating side of the communication stores the terminal ID of the originating side terminal in advance and accepts the terminal number of the terminating side terminal that is the terminating side of the communication when starting the communications, and the accepted terminal number And the stored terminal ID,
The highest layer node, which is the highest layer node among the plurality of hierarchized nodes, receives the terminal number and the terminal ID transmitted from the originating terminal, and the received terminal number is in the first format. The location information associated with the received terminal number is compared with the location information associated with the received terminal ID based on the subscriber information. When the position information matches, the lowest-layer node identified by the matched position information is set as the relay node, and as a result of the comparison, when the two position information does not match, based on the group information, It is confirmed whether or not the two position information belongs to the same group, and if the two position information belongs to the same group as a result of the confirmation, before the two position information are identified by each of the two position information Communication system and each of the lowermost node, and said each said node lowermost node is connected to the relay node. The communication system according to claim 1 ,
A communication system in which each of the plurality of terminals and the lowermost node are wirelessly connected. There are a plurality of nodes that are hierarchized and connected to nodes in adjacent hierarchies, and a plurality of terminals, and there are a plurality of lowermost nodes among the plurality of hierarchized nodes, and Each of the plurality of hierarchized nodes corresponding to each of the lowest layer nodes to which the plurality of terminals that are connected are connected to any of the plurality of lowest layer nodes and perform communication. a relay control method in a communication system for relaying using a node determines a relay node for relaying, the determined communication between said plurality of terminals,
When the originating terminal that is the originator of communication starts communications, it accepts the terminal number of the terminating terminal that is the recipient of the communication, and the received terminal number and the terminal of the sender terminal that is stored in advance A process of transmitting the ID;
A process in which a top layer node, which is a top layer node among the plurality of hierarchized nodes, receives a terminal number and a terminal ID transmitted from the originating terminal;
The uppermost layer node identifies a terminal ID identifying each of the plurality of terminals, position information identifying the lowest layer node to which each of the plurality of terminals is connected, and the plurality of terminals when performing communication If the received terminal number is in the first format, the received terminal number is associated with the received terminal number based on the subscriber information associated with the first and second format terminal numbers for identifying each A process of comparing the received location information with the location information associated with the received terminal ID;
When the uppermost node matches the two pieces of position information as a result of the comparison, a process of setting the lowermost node identified by the matched position information as the relay node;
If the top layer node does not match the two position information as a result of the comparison, a process of checking whether the two position information belongs to the same group based on group information obtained by grouping the position information When,
As a result of the confirmation, if the two position information belongs to the same group, the uppermost layer node and each of the lowermost node identified by each of the two position information and the respective uppermost node A relay control method including a process of setting a node to which a lower-layer node is connected as the relay node . In the relay control method according to claim 3 ,
The relay control method in which each of the plurality of terminals and the lowermost node are connected by radio.

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