JPWO2014162691A1 - Cellular communication system, mobile station, base station, control node, and method related thereto - Google Patents

Abstract

The mobile station (400A) receives broadcast information broadcast in the cell (310) from the base station (300) so that a plurality of mobile stations (400A and 400B) can receive the encrypted information included in the broadcast information. Configured to process messages. Here, the encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station (400A) among the plurality of mobile stations (400A and 400B). Thereby, for example, the mobile station that should use (or discard) the content included in the cell broadcast information can be specified with fine granularity.

Description

  The present invention relates to a cellular communication system for broadcasting a message to a plurality of mobile stations in a cell.

  In the field of cellular communication networks, systems are known that broadcast messages to a plurality of mobile stations that are camping on a cell. For example, the 3rd Generation Partnership Project (3GPP) defines Cell Broadcast Service (CBS) (see Non-Patent Document 1). The main use of CBS is to deliver important warning messages to mobile stations. 3GPP defines a Public Warning System (PWS) that distributes important warning messages to mobile stations using CBS (see Non-Patent Document 2). 3GPP Release 11 is used as an PWS for the Earthquake and Tsunami Warning System (ETWS) used in Japan, the Commercial Mobile Alert System (CMAS) used in North America, the Korean Public Alert System (KPAS) used in Korea, and European countries Standardized EU-ALERT. Note that KPAS and EU-ALERT are minor variations of CMAS, and KPAS and EU-ALERT alarm messages are delivered to mobile stations in the same manner as CMAS. Therefore, explicit reference to KPAS and EU-ALERT will be omitted below, but the description regarding CMAS below applies to KPAS and EU-ALERT as well.

  The mobile station can receive PWS notification (that is, ETWS notification and CMAS notification) when connected to the Home Public Land Mobile Network (HPLMN) in order to receive normal service (see Non-Patent Documents 1 and 2). reference). Further, the mobile station can receive the PWS notification even when roaming, that is, when connected to the Visited PLMN (VPLM) to receive normal service (see Non-Patent Documents 1 and 2). .

  Furthermore, a mobile station that supports ETWS or CMAS can receive ETWS notification or CMAS notification in the limited service state (see Non-Patent Documents 2 and 3). Here, limited service means emergency call, ETWS and CMAS. A mobile station is responsible for PLMN identity if the Universal Subscriber Identification Module (USIM) is not implemented, if it cannot find a suitable public land mobile network (PLMN) cell, or if location registration fails. First, camp on the acceptable cell and enter the limited service state. A mobile station in a limited service state can initiate an emergency call, receive an ETWS notification, and receive a CMAS.

  The alarm message delivery procedure in Universal Mobile Telecommunications System (UMTS) and Evolved Packet System (EPS) is defined in Non-Patent Document 1. FIG. 15 shows the configuration of a distribution network for alarm messages (specifically, CBS messages) in UMTS and EPS. FIG. 16 is a sequence diagram showing an alarm message delivery procedure in UMTS. FIG. 17 is a sequence diagram showing an alarm message delivery procedure in EPS, that is, Long Term Evolution (LTE).

  The Cell Broadcast Entity (CBE) described in FIGS. 15 to 17 is an apparatus or system for message delivery that makes a transmission request for an alarm message. For example, a server of the Japan Meteorological Agency that transmits earthquake early warnings corresponds to CBE. The Cell Broadcast Center (CBC) receives an alarm message transmission request from the CBE, determines an alarm message distribution area, and determines the contents of the alarm message. The distribution area is based on information for specifying the target area included in the transmission request from the CBE, based on the sector unit, cell unit, location registration area (eg routing area, tracking area) unit, or communication carrier It is determined in any other area unit to be defined.

  In the case of UMTS, CBC has an interface with Radio Network Controller (RNC) or Serving GPRS Support Node (SGSN). In the examples of FIGS. 15 and 16, the CBC is connected to the RNC. The CBC sends a Write-Replace message to the RNC. The Write-Replace message includes the content of the alarm message to be distributed to the mobile station and the designation of the distribution area. Based on the Write-Replace message, the RNC determines a base station (that is, NodeB) to which the alarm message is to be distributed, and requests the target base station (NodeB) to broadcast the alarm message. Then, the base station (NodeB) transmits broadcast information including an alarm message using downlink channels received by a plurality of mobile stations located in its own cell.

  In the case of UMTS, the alert message is broadcast using Common Traffic Channel (CTTH), which is a downlink logical channel. CTTH is mapped to a Forward Access Channel (FACH) that is a transport channel and is transmitted on a Secondary Common Control Physical Channel (S-CCPCH) that is a physical channel. The base station (NodeB) transmits CTTH Indicator indicating CTTH transmission as broadcast information. Specifically, CTTH Indicator is transmitted as one of system information (that is, System Information Block Type 5 (SIB5)) in Primary Common Control Physical Channel (P-CCPCH) and Broadcast Control Channel (BCCH). Further, the base station (NodeB) transmits a paging message indicating that the system information (BCCH) is changed on the S-CCPCH, thereby prompting the mobile station in a standby state to receive the system information.

  The above-described transmission using CTTH in UMTS is used for transmission of ETWS Secondary Notification and CMAS notification. On the other hand, the ETWS Primary Notification is transmitted using a paging message indicating that there is a change in system information.

  The mobile station of UMTS can receive ETWS Primary Notification, ETWS Secondary Notification, and CMAS notification when in a standby state (CELL_PCH state, URA_PCH state). Also, a UMTS mobile station can receive an ETWS Primary Notification when in a communication state (CELL_DCH state). Further, even in the limited service state, the UMTS mobile station can receive the ETWS Secondary Notification and the CMAS notification by receiving the system information.

  The distribution of the alarm message in EPS shown in FIG. 17 is also performed by the almost same architecture as that of UMTS. However, in EPS, the CBC is connected to the mobility management entity (MME), and the alarm message is supplied to the base station (eNodeB) via the MME. The base station (eNodeB) transmits an ETWS Indication bit indicating that the alarm message is delivered using the paging message. The paging message is mapped to the Paging Channel (PCH) and transmitted on the Physical Downlink Shared Channel (PDSCH). Then, the base station (eNodeB) transmits system information (System Information Block (SIB)) including an alarm message. ETWS Primary Notification is transmitted in SIB Type 10 (SIB10), and ETWS Secondary Notification is transmitted in SIB Type 11 (SIB11). CMAS Notification is transmitted in SIB Type 12 (SIB12). The base station (eNodeB) broadcasts system information including an alarm message in the cell using the Broadcast Control Channel (BCCH) / Downlink Shared Channel (DL-SCH) / Physical Downlink Shared Channel (PDSCH).

  An EPS mobile station attempts to receive a paging message at least once in the Default Paging Cycle, regardless of whether it is in a standby state (RRC_IDLE state) or a communication state (RRC_CONNECTED state). Then, in response to receiving the paging message in which the ETWS Indication bit is set, the mobile station starts receiving system information (SIB) including an alarm message. Therefore, an EPS mobile station can perform ETWS Primary Notification, ETWS Secondary Notification, and CMAS notification in any of a standby state (RRC_IDLE state) and a communication state (RRC_CONNECTED state). Further, even when the EPS mobile station is in the limited service state, it can receive ETWS Primary Notification, ETWS Secondary Notification, and CMAS notification by receiving system information.

3GPP TS 23.041 V11.5.0 (2012-12) “3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Technical realization of Cell Broadcast Service (CBS) (Release 11)”, December 2012 3GPP TS 22.268 V11.5.0 (2012-12) “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Public Warning System (PWS) requirements (Release 11)”, December 2012 3GPP TS 36.304 V11.2.0 (2012-12) “3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode (Release 11)”, December 2012 3GPP TS 23.682 V11.3.0 (2012-12) “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Architecture enhancements to facilitate communications with packet data networks and applications (Release 11)”, December 2012

  The inventors of this case examined the expansion of the use of cell broadcast information. Here, the cell broadcast information means information broadcast in a cell so that a plurality of mobile stations can receive the content (message) for the mobile station. A specific example of cell broadcast information is a CBS message broadcast in the CBS architecture. As described above, the distribution of a highly important alarm message such as PWS notification is one of the main uses of cell broadcast, but the use of cell broadcast is not limited to this. When the use of cell broadcast is expanded, the inventors of the present case may discard the content (message) included in the cell broadcast information without presenting it to the user in a mobile station that does not need to receive the cell broadcast information. We found that there are favorable cases.

  Non-Patent Document 1 describes that cell broadcast information (specifically, CBS message) in the CBS architecture is identified by a message identifier. Furthermore, Non-Patent Document 1 discards a CBS message to which a message identifier in a PLMN operator specific range (ie, A000 hex to AFFF hex) is assigned, unless the mobile station receives it from HPLMN (or Equivalent HPLMN). It stipulates that it should be. However, in this case, all mobile stations that have received the CBS message to which the Message Identifier within the PLMN operator specific range is assigned from the HPLMN operate to present the content included in the CBS message to the user. Also, all mobile stations that have received a CBS message to which a Message Identifier within the PLMN operator specific range is assigned from other than HPLMN operate so as to discard the CBS message. That is, it is determined whether the content included in the CBS message is to be presented to the user or discarded based only on the index indicating whether the CBS message that is a PLMN operator specific is received from the HPLMN. Therefore, the technique of Non-Patent Document 1 may have too coarse a granularity to specify a mobile station that should present (or discard) the content included in the CBS message to the user.

  Accordingly, one of the objects of the present invention is to provide a cellular communication system, a mobile station, and a base for specifying a mobile station that should use (or discard) the content included in the cell broadcast information with fine granularity. It is to provide a station, a control node, and a method and a program related thereto.

  In the first aspect, the cellular communication system includes a control node, a base station, and a plurality of mobile stations. The control node is configured to send a broadcast request including an encrypted message to the base station. The base station is configured to receive the broadcast request and broadcast in a cell so that the plurality of mobile stations can receive broadcast information including the encrypted message. Each of the plurality of mobile stations is configured to receive the broadcast information including the encrypted message in the cell. Furthermore, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In the second aspect, the mobile station includes a radio communication unit and a message processing unit. The wireless communication unit is configured to receive broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive the wireless communication unit. The message processing unit is configured to process an encrypted message included in the broadcast information. Here, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In the third aspect, the base station includes a transmitter that broadcasts in a cell so that a plurality of mobile stations can receive broadcast information including an encrypted message. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In the fourth aspect, the control node includes a control unit that transmits a broadcast request including the encrypted message to the base station. The broadcast request causes the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message. Furthermore, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In a fifth aspect, a message distribution system includes a distribution control unit that transmits a broadcast request including an encrypted message to a cellular communication network. The broadcast request causes the cellular communication network to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message. Furthermore, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In a sixth aspect, a method performed in a mobile station includes receiving broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive, and an encrypted message included in the broadcast information Processing. Here, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In a seventh aspect, a method performed in a base station includes broadcasting in a cell so that a plurality of mobile stations can receive broadcast information including an encrypted message. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In an eighth aspect, a method performed at a control node includes sending a broadcast request including an encrypted message to a base station. The broadcast request causes the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message. Furthermore, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In a ninth aspect, a method performed in a message delivery system includes sending a broadcast request that includes an encrypted message to a cellular communication network. The broadcast request causes the cellular communication network to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message. Furthermore, the encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In a tenth aspect, a program includes a group of instructions for causing a computer to perform a control method related to a mobile station. The control method includes processing an encrypted message included in broadcast information broadcast in a cell from a base station so that a number of mobile stations can receive it. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In the eleventh aspect, the program includes a group of instructions for causing a computer to perform a control method related to the base station. The control method includes controlling the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including an encrypted message. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In a twelfth aspect, a program includes a group of instructions for causing a computer to perform a control method related to a control node. The control method includes controlling the control node to transmit a broadcast request including an encrypted message to a base station. The broadcast request causes the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  In the thirteenth aspect, the program includes a group of instructions for causing a computer to perform a control method related to the message delivery system. The control method includes controlling the message delivery system to send a broadcast request including an encrypted message to a cellular communication network. The broadcast request causes the cellular communication network to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station among the plurality of mobile stations.

  According to the above-described aspect, the cellular communication system, the mobile station, the base station, and the control for enabling the mobile station that should use (or discard) the content included in the cell broadcast information to be specified with fine granularity. Nodes and methods and programs related to them can be provided.

It is a block diagram which shows the structural example of the cellular communication system which concerns on 1st Embodiment. It is a sequence diagram which shows an example of the delivery procedure of the cell broadcast information containing the encrypted message which concerns on 1st Embodiment. It is a sequence diagram which shows an example of the distribution procedure of the decryption key for decrypting the encrypted message which concerns on 1st Embodiment. It is a sequence diagram which shows the other example of the distribution procedure of the decryption key for decrypting the encrypted message which concerns on 1st Embodiment. It is a sequence diagram which shows an example of the registration procedure of the new message delivery service which concerns on 1st Embodiment. It is a block diagram which shows the structural example of the message delivery system which concerns on 1st Embodiment. It is a block diagram which shows the structural example of the broadcast node which concerns on 1st Embodiment (in the case of EPS). It is a block diagram which shows the structural example of the control node which concerns on 1st Embodiment (in the case of EPS). It is a block diagram which shows the structural example of the base station which concerns on 1st Embodiment (in the case of EPS). It is a block diagram which shows the structural example of the mobile station which concerns on 1st Embodiment. It is a block diagram which shows the structural example of the cellular communication system which concerns on 2nd Embodiment. It is a sequence diagram which shows an example of the delivery procedure of the cell broadcast information containing the encrypted message which concerns on 2nd Embodiment. It is a block diagram which shows the structural example of the cellular communication system which concerns on 3rd Embodiment. It is a sequence diagram which shows an example of the delivery procedure of the cell broadcast information containing the encrypted message which concerns on 3rd Embodiment. It is a figure which shows the structure of the delivery network of the alarm message in UMTS and EPS concerning a background art. It is a sequence diagram which shows the delivery procedure of the alarm message which concerns on background art (in the case of UMTS). It is a sequence diagram which shows the delivery procedure of the alarm message which concerns on background art (in the case of EPS).

  Hereinafter, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted as necessary for clarification of the description.

<First Embodiment>
FIG. 1 is a block diagram illustrating a configuration example of a cellular communication system 1 according to the present embodiment. In the present embodiment and other embodiments described later, the case where the cellular communication system 1 is a 3GPP UMTS or EPS will be described.

  The cellular communication system 1 includes a plurality of mobile stations (User Equipment (UE)) 400, a message distribution system 500, and a cellular communication network 10. The cellular communication network 10 performs cell broadcast of cell broadcast information. Cell broadcast information refers to information broadcast in a cell so that a plurality of mobile stations 400 can receive the content (message) for the mobile station. In the case of UMTS and EPS, the cell broadcast information may be a CBS message. The cellular communication network 10 includes a broadcast node 100, a control node 200, and a base station 300 as nodes related to cell broadcast. The cell broadcast by the cellular communication network 10 may be performed in the same manner as the cell broadcast using the CBS architecture described in the background art. Below, the cell broadcast in the cellular communication system 1 which concerns on this embodiment is demonstrated.

  The message distribution system 500 corresponds to Cell Broadcast Entity (CBE), and transmits a broadcast request to the cellular communication network 10. In the present embodiment, the message distribution system 500 transmits a broadcast request including an encrypted message to be cell broadcast to the cellular communication network 10. The encrypted message is encrypted so that it can be decrypted with a decryption key held only in at least one specific mobile station 400A among the plurality of mobile stations 400. Therefore, the specific mobile station 400A can receive the cell broadcast information including the encrypted message and decrypt the encrypted message. On the other hand, the mobile station 400B that does not hold the decryption key can receive the cell broadcast information, but cannot decrypt the encrypted message included therein.

  The broadcast node 100 corresponds to a Cell Broadcast Center (CBC), receives a broadcast request including an encrypted message from the message distribution system 500, determines a distribution area of cell broadcast information, and a control node corresponding to the distribution area 200 transmits a broadcast request.

  The control node 200 is a node having an interface with the broadcast node 100. In the case of EPS, the mobility management entity (MME) corresponds to the control node 200, and in the case of UMTS, the radio network controller (RNC) corresponds to the control node 200. The control node 200 receives a broadcast request (that is, a UMTS Write-Replace message or an EPS Write-Replace-Warning-Request message) from the broadcast node 100. This broadcast request includes content to be broadcast (that is, an encrypted message in the present embodiment) and a distribution area specification. The control node 200 determines a base station 300 to perform cell broadcast based on the distribution area information, and requests the target base station 300 to perform cell broadcast.

  The base station 300 manages the cell 310 and can perform bidirectional wireless communication with a plurality of mobile stations 400 in the cell 310 using an uplink channel and a downlink channel. In the case of EPS, eNodeB corresponds to the base station 300, and in the case of UMTS, NodeB corresponds to the base station 300. The base station 300 receives a broadcast request (that is, a UMTS Broadcast Request message or an EPS Write-Replace-Warning-Request message) from the control node 200. In response to receiving the broadcast request, the base station 300 broadcasts the cell broadcast information including the encrypted message in the cell 310 so that the plurality of mobile stations 400 can receive the broadcast request. As already described, in the case of UMTS, cell broadcast information is transmitted using, for example, CTTH (or CTTH and a paging signal). In the case of EPS, for example, cell broadcast information is transmitted by being included in system information.

  Each of the plurality of mobile stations (UEs) 400 receives broadcast information including encrypted messages in the cell 310. As already described, the specific mobile station 400A among the plurality of mobile stations 400 holds the decryption key, can decrypt the encrypted message, and can acquire the decrypted message. Since the other mobile station 400B does not hold the decryption key, it cannot decrypt the encrypted message included in the broadcast information. Accordingly, the other mobile station 400B may discard the broadcast information including the encrypted message or the encrypted message included in the broadcast information.

  A decryption key for decrypting an encrypted message included in the cell broadcast information may be stored in advance in a USIM or the like installed in the specific mobile station 400. Further, the decryption key may be transmitted from the message distribution system 500 or another node to the specific mobile station 400 via the user plane or the control plane.

  As understood from the above description, in the cellular communication system 1 of this embodiment, the content (message) included in the cell broadcast information is encrypted, and only the specific mobile station 400A holding the decryption key is used. Decrypted content can be obtained. That is, in this embodiment, the mobile station 400 that should use the content included in the cell broadcast information is limited to the specific mobile station 400A having the decryption key. For example, when a plurality of mobile stations 400 receive cell broadcast information from the HPLMN common to them, only the specific mobile station 400 having the decryption key can decrypt and use the encrypted content (message). . Therefore, according to the present embodiment, the mobile station 400 that should use (or discard) the content included in the cell broadcast information can be specified with a fine granularity using the presence or absence of the decryption key as an index.

  Next, a specific example of a procedure for distributing cell broadcast information including an encrypted message will be described below. FIG. 2 is a sequence diagram illustrating an example of a procedure for distributing cell broadcast information including an encrypted message. FIG. 2 shows a case where the cellular communication system 1 is EPS.

  In step S11, the message delivery system 500 (for example, CBE) transmits a broadcast request including the encrypted message to the broadcast node 100 (for example, CBC). In step S12, the broadcast node 100 transmits a Write-Replace Warning Request message including the encrypted message to the control node 200 (for example, MME). In step S <b> 13, the control node 200 selects a base station 300 that should perform cell broadcast, and transmits a Write-Replace Warning Request message including an encrypted message to the selected base station 300. In step S14, the base station 300 broadcasts the cell broadcast information including the encrypted message in the cell 310. The specific mobile station 400A that holds the decryption key receives the cell broadcast information, receives the encrypted message, and uses the decrypted message (step S15). For example, the specific mobile station 400A may present the decoded message to the user, or may control the operation of the specific mobile station 400 according to the decoded message. On the other hand, the mobile station 400B that does not hold the decryption key receives the cell broadcast information and discards the encrypted message included therein (step S16).

  The cell broadcast information may include an indication that the message is encrypted. The display notifies the mobile station 400 that the message is encrypted. Further, the display may notify the mobile station 400 which one of a plurality of decryption keys related to a plurality of message delivery services should be used. For example, the display may be a specific identifier of cell broadcast information assigned to each message delivery service (for example, a specific Message Identifier in a CBS message). For example, the display may be included in the cell broadcast information as content together with the encrypted message.

  The display indicating that the message is encrypted may include a first display indicating whether or not the message is encrypted and a second display for specifying a decryption key to be used. The first display may be, for example, a specific identifier of cell broadcast information (for example, a specific message identifier in a CBS message). The second display may be included in the cell broadcast information as content, for example. In this case, the content (or payload) of the cell broadcast information includes an unencrypted plaintext second display and an encrypted message. In general, the data size (number of octets) of the identifier of cell broadcast information is smaller than the data size (number of octets) of the content of cell broadcast information. Therefore, by using the content of the cell broadcast information, it is possible to easily identify a plurality of decryption keys (that is, a plurality of message delivery services).

  Next, a specific example of the decryption key distribution procedure will be described with reference to FIGS. FIG. 3 shows an example of a procedure for distributing a decryption key via a user plane (U-Plane). In step S21, the specific mobile station 400A transmits a request for subscription to the message distribution service to the message distribution system 500 via the user plane. The user plane refers to a network that transfers user packets transmitted or received to the mobile station 400. In the case of EPS, the user plane includes a Serving Gateway (S-GW) and a Packet Data Network Gateway (P-GW). In step S22, the message delivery system 500 transmits a response to the subscription request to the specific mobile station 400A via the user plane. The response to the subscription request includes a decryption key for decrypting the encrypted message included in the cell broadcast information. In step S23, the specific mobile station 400A stores the received decryption key in a memory in the specific mobile station 400A.

  FIG. 4 shows an example of the procedure for distributing the decryption key via the control plane (C-Plane). In step S31, the specific mobile station 400A establishes an RRC (Radio Resource Control) connection with the base station 300 prior to transmission of an attach request message. In step S32, the specific mobile station 400A transmits an attach request message. The attach request message is transmitted to the core network via the base station 300. Since FIG. 4 shows the case where the control node 200 is an MME, the attach request message is sent to the control node 200. In step S33, the control node 200 requests the subscriber information server 209 to authenticate the specific mobile station 400A, update the location of the specific mobile station 400A (location registration), or both in response to receiving the attach request message. In the case of EPS, the subscriber information server 209 corresponds to a Home Subscriber Server (HSS). The subscriber information server 209 manages the decryption key to be transmitted to the specific mobile station 400A, and transmits an acknowledgment including the decryption key to the control node 200 (step S34). In step S35, the control node 200 transmits an attach acceptance message including the decryption key to the specific mobile station 400A. In step S36, the specific mobile station 400A stores the received decryption key in a memory in the specific mobile station 400A.

  The procedures in FIGS. 3 and 4 are examples. For example, the specific mobile station 400A may receive the code necessary for generating the decryption key from the message distribution system 500 or the subscriber information server 209 instead of the decryption key itself. In this case, the specific mobile station 400A may generate a decryption key using the received code. Further, the specific mobile station 400A may receive the decryption key not when transmitting the attach request message but when transmitting the bearer establishment request message, the service request message, or the location registration update request message.

  Next, a specific example of a new message delivery service registration procedure will be described with reference to FIG. In step S41, the message distribution system 500 (for example, CBE) transmits a new message distribution service registration request to the broadcast node 100 (for example, CBC). The registration request includes, for example, a service identifier (ID: Identifier) indicating a new message delivery service. In step S42, the broadcast node 100 receives the registration request and assigns a Message Identifier to a new message delivery service related to the registration request. The Message Identifier is used to identify the encrypted message, broadcast request, and broadcast information for the new message delivery service. The Message Identifier may be, for example, a Message Identifier assigned to a CBS message or a Warning Type Value (WTV).

  In step S43, the broadcast node 100 transmits a response (positive response or negative response) to the registration request in step S41 to the message distribution system 500. When the acknowledgment is received, the message delivery system 500 generates a decryption key for decrypting the encrypted message related to the new message delivery service (step S44). In step S44, the message delivery system 500 may also generate an encryption key for encrypting the message. When the decryption key is distributed via the control plane shown in FIG. 4, the message delivery system 500 may transmit the decryption key to the subscriber information server 209 (step S45). On the other hand, when the decryption key is transmitted from the message distribution system 500 to the specific mobile station 400A according to the procedure shown in FIG. 3, step S45 is omitted.

  Next, block diagrams (FIGS. 6 to 10) of the message distribution system 500, the broadcast node 100, the control node 200, the base station 300, and the mobile station 400 will be described below. 6 to 10 show only main components related to the description of the cell broadcast.

  FIG. 6 is a block diagram illustrating a configuration example when the message delivery system 500 is a CBE. The distribution control unit 501 determines message distribution by cell broadcast, and transmits a broadcast request including the encrypted message to the broadcast node 100. The broadcast request may include message delivery area information.

  FIG. 7 is a block diagram illustrating a configuration example when the broadcast node 100 is a CBC. The distribution request unit 101 receives a broadcast request from the message distribution system 500, identifies the control node 200, and transmits a broadcast request (that is, a Write-Replace Warning Request message) to the control node 200. In the present embodiment, the Write-Replace Warning Request message includes an encrypted message.

  FIG. 8 is a block diagram illustrating a configuration example when the control node 200 is an MME. The distribution request unit 201 receives a broadcast request (that is, a Write-Replace Warning Request message) from the broadcast node (CBC) 100, determines a base station (eNodeB) 300 to perform cell broadcast, and determines a target base station (eNodeB ) 300 to send a broadcast request (that is, a Write-Replace Warning Request message). In the present embodiment, the Write-Replace Warning Request message includes an encrypted message.

  FIG. 9 is a block diagram illustrating a configuration example when the base station 300 is an eNodeB. The wireless communication unit 301 wirelessly transmits a downlink signal including a plurality of downlink channels, and receives an uplink signal including a plurality of uplink channels from the mobile station 400. The plurality of downlink channels include a broadcast channel (for example, CTTH or BCCH) used for transmission of cell broadcast information, a paging channel (for example, Paging Control Channel (PCCH)), and the like. The broadcast unit 302 receives a broadcast request (that is, a Write-Replace Warning Request message) from the control node 200, and controls the radio communication unit 301 to transmit cell broadcast information including an encrypted message.

  FIG. 10 is a block diagram illustrating a configuration example of the mobile station 400. The wireless communication unit 401 can receive a downlink signal including a plurality of downlink channels from the base station 300. Further, the radio communication unit 401 can transmit an uplink signal including a plurality of uplink channels to the base station 300. The wireless communication unit 401 receives cell broadcast information broadcast from the base station 300 in the cell 310 and supplies an encrypted message included in the cell broadcast information to the message processing unit 402.

  When the decryption key is held in the mobile station 400, the message processing unit 402 decrypts the encrypted message using the decryption key, and uses the decrypted message. On the other hand, if the decryption key is not held in the mobile station 400, the message processing unit 402 discards the encrypted message.

<Second Embodiment>
In the present embodiment, a modified example of the above-described first embodiment will be described. Specifically, this embodiment shows an example in which the first embodiment is applied to Machine Type Communication (MTC). 3GPP and the European Telecommunications Standards Institute (ETSI) are considering standardization of MTC. MTC is also called a Machine-to-Machine (M2M) network or a sensor network. 3GPP defines a mobile station (User equipment (UE)) mounted on a machine and a sensor for MTC as an “MTC device”. MTC devices are mounted on various devices such as machines (eg, vending machines, gas meters, electric meters, automobiles, railway vehicles) and sensors (eg, sensors related to environment, agriculture, traffic, etc.). The MTC device connects to the Public Land Mobile Network (PLMN) and communicates with the MTC application server (Application Server (AS)). The MTC application server is arranged outside the PLMN (external network), executes the MTC application, and communicates with the MTC UE application installed in the MTC device. The MTC application server is generally controlled by an MTC service provider (M2M service provider).

  3GPP is a network architecture that includes Service Capability Server (SCS) and Machine Type Communication Interworking Function (MTC-IWF), and reference points (interfaces) related to these to enable MTC application servers to communicate with MTC devices. ) (See Non-Patent Document 4). The SCS is an entity that connects an MTC application server to a 3GPP PLMN and enables the MTC application server to communicate with a UE (that is, an MTC device) via a PLMN service defined by 3GPP. The SCS also enables the MTC application server to communicate with the MTC-IWF. It is assumed that the SCS is controlled by a PLMN operator or an MTC service provider.

  MTC-IWF is a control plane entity belonging to PLMN. MTC-IWF has a connection with SCS, and nodes in PLMN (for example, Home Subscriber Server (HSS), Short Message Service-Service Center (SMS-SC), Serving GPRS Support Node (SGSN), Mobility Management Entity) (MME), Mobile Switching Center (MSC)). The MTC-IWF acts as a control plane interface for interworking between the M2M service layer including the SCS and the 3GPP PLMN while hiding the details of the 3GPP PLMN topology.

  3GPP assumes a direct model, an indirect model, and a hybrid model as end-to-end communication architecture between the MTC application of the mobile station and the MTC application server. In the direct model, the MTC application server directly connects to the PLMN in order to perform user plane communication with the mobile station. On the other hand, in the indirect model, the MTC application server is indirectly connected to the PLMN via the SCS. In the indirect model, the MTC application server can use services such as device triggering on the control plane, and can perform user plane communication with a mobile station via the SCS. The hybrid model is a combination of the direct model and the indirect model described above.

  FIG. 11 is a block diagram illustrating a configuration example of the cellular communication system according to the present embodiment. FIG. 11 shows the indirect model described above. That is, the MTC application server 52 is connected to the cellular communication network (PLMN) 10 via the SCS 51. The SCS 51 has an interface with the MTC-IWF entity 16 in order to use the control plane service, and has an interface with the P-GW 18 for user plane communication.

  The MTC-IWF entity 16 is a control plane entity belonging to the cellular communication network (PLMN) 10. The MTC-IWF entity 16 may be a single independent physical entity, or may be a functional element added to another network entity (for example, the HSS 209 or the MME 200). The MTC-IWF entity 16 has a connection with the SCS 51 via a Tsp reference point. The Tsp reference point is, for example, Application Programming Interfaces (API), and uses a Diameter-based protocol. The MTC-IWF entity 16 has a connection with a node in the cellular communication network (PLMN) 10. Specifically, the MTC-IWF entity 16 has a connection with the HSS as the subscriber information server 209 via the S6m reference point, and the Charging Data Function / Charging Gateway Function (CDF) via the Rf / Ga reference point. / CGF) 13 and a connection with the MME as the control node 200 via the T5b reference point. Further, in the example of FIG. 11, the MTC-IWF entity 16 has a connection with the CBC as the broadcast node 100.

  The specific mobile station 400A shown in FIG. 11 executes the MTC UE application 410 and behaves as an MTC device. A mobile station 400A as an MTC device is connected to a cellular communication network (PLMN) 10 via a radio access network (RAN) 15 including a base station 300. Then, the mobile station 400A performs user plane communication with the MTC application server 52 via the S-GW 17 and the P-GW 18. Furthermore, the mobile station 400A uses a control plane service, for example, a cell broadcast service provided by the broadcast node 100, the control node (MME) 200, and the base station (eNodeB) 300.

  In the cellular communication system shown in FIG. 11, the MTC-IWF entity 16, the SCS 51, and the MTC application server 52 can be regarded as corresponding to the message delivery system (CBE) 500 according to the first embodiment. Note that the configuration example of FIG. 11 is merely an example. For example, the broadcast node 100 may have an interface with the SCS 51 or the MTC application server 52. In this case, it can be considered that the SCS 51, the MTC application server 52, or the SCS 51 and the MTC application server 52 correspond to the message delivery system (CBE) 500 according to the first embodiment.

  Subsequently, a specific example of a procedure for distributing cell broadcast information including an encrypted message according to the present embodiment will be described below. The basic distribution procedure of this embodiment may be the same as that of the first embodiment. Therefore, a specific example of signaling in the MTC-IWF entity 16, the SCS 51, the MTC application server 52, and the like will be mainly described here.

  FIG. 12 is a sequence diagram showing an outline of a procedure for distributing cell broadcast information according to the present embodiment. In step S51, registration of a new message delivery service is performed. Step S51 corresponds to the message delivery service registration procedure described with reference to FIG. In step S52, the message is registered with the specific mobile station 400A that receives the new service and the decryption key is distributed to the specific mobile station 400A. Step S52 corresponds to the decryption key distribution procedure via the user plane described with reference to FIG. 3 or the decryption key distribution procedure via the control plane described with reference to FIG. In step S53, cell broadcast information including an encrypted message is broadcast. Step S53 corresponds to the distribution procedure of the cell broadcast information described with reference to FIG.

  Steps S51 to S53 may be performed according to any one of Pattern 1 to Pattern 4 shown below.

<Pattern 1>
In pattern 1, the MTC-IWF entity 16 is responsible for generating encryption keys and decryption keys and encrypting messages. Distribution of the decryption key to the specific mobile station 400A is performed via the user plane. Pattern 1 includes the processes listed in the following (1A) to (1C).

(1A) Message delivery service registration phase (step S51)
The MTC application server 52 requests a message delivery service from the SCS 51.
-SCS51 produces | generates the service ID matched with the new message delivery service.
The SCS 51 transmits a service registration request including the service ID to the MTC-IWF entity 16.
The MTC-IWF entity 16 requests a message ID (for example, Warning Type Value (WTV)) from the broadcast node (CBC) 100.
The broadcast node (CBC) 100 assigns a free message ID (for example, WTV), and notifies the MTC-IWF entity 16 of the assigned message ID.
The MTC-IWF entity 16 generates an encryption key and a decryption key corresponding to the service ID and message ID (for example, WTV) (the encryption key and the decryption key may be the same. Necessary for generating the encryption key and the decryption key) Code may be generated.)
The MTC-IWF entity 16 associates and manages an encryption key and a decryption key corresponding to a service ID and a message ID (for example, WTV).
The MTC-IWF entity 16 transmits a message ID (for example, WTV) and a decryption key to the SCS 51 (transmission of the encryption key is not necessary).
The SCS 51 associates and manages a service ID, a message ID (for example, WTV), and a decryption key.
The SCS 51 transmits a registration completion response including the service ID to the MTC application server 52.

(1B) Mobile station registration and decryption key distribution phase (step S52)
The specific mobile station 400A requests the SCS 51 to subscribe to the message delivery service.
The SCS 51 associates the identifier of the specific mobile station 400A with the message delivery service (for example, for billing).
-SCS51 transmits service ID, message ID (for example, WTV), and a decryption key to the specific mobile station 400A.
The specific mobile station 400A manages the service ID, the message ID (for example, WTV), and the decryption key in association with each other.

(1C) Message distribution phase (step S53)
The MTC application server 52 transmits a broadcast request (including a service ID, a message to be distributed, a distribution policy, etc.) to the SCS 51.
The SCS 51 sends a broadcast request (including service ID, message to be distributed, distribution policy, etc.) to the MTC-IWF entity 16.
The MTC-IWF entity 16 encrypts the message with the encryption key corresponding to the service ID included in the broadcast request.
The MTC-IWF entity 16 transmits a broadcast request (including a message ID (eg, WTV), an encrypted message, a distribution policy, etc.) to the broadcast node (CBC) 100.
The broadcast node (CBC) 100 requests the control node (MME) 200 that manages the distribution area specified based on the distribution policy to transmit the encrypted message by cell broadcast.
The control node (MME) 200 requests the cell broadcast of the encrypted message from the base station (eNodeB) 300.
The specific mobile station 400A receives the cell broadcast information in the cell 310, and decrypts and uses the encrypted message.
The other mobile station 400B that is not registered in the message distribution service discards the broadcast information in which the WTV that is not managed by the mobile station 400B is specified. The other mobile station 400B may discard the encrypted message in response to the inability to decrypt the encrypted message.

<Pattern 2>
In pattern 2, the SCS 51 is responsible for generating the encryption key and decryption key and encrypting the message. Distribution of the decryption key to the specific mobile station 400A is performed via the user plane. Pattern 2 includes the processes listed in the following (2A) to (2C). The process in phase (2B) is the same as the process in phase (1B) described above.

(2A) Message distribution service registration phase (step S51)
The MTC application server 52 requests a message delivery service from the SCS 51.
-SCS51 produces | generates the service ID matched with the new message delivery service.
The SCS 51 transmits a service registration request including the service ID to the MTC-IWF entity 16.
The MTC-IWF entity 16 requests a message ID (for example, Warning Type Value (WTV)) from the broadcast node (CBC) 100.
The broadcast node (CBC) 100 assigns a free message ID (for example, WTV), and notifies the MTC-IWF entity 16 of the assigned message ID.
The MTC-IWF entity 16 manages the service ID and the message ID (for example, WTV) in association with each other.
The MTC-IWF entity 16 transmits a message ID (for example, WTV) to the SCS 51.
-The SCS 51 generates an encryption key and a decryption key corresponding to the service ID and message ID (for example, WTV). (The encryption key and the decryption key may be the same. The code necessary for generating the encryption key and the decryption key is generated. May be.)
The SCS 51 associates and manages a service ID, a message ID (for example, WTV), and an encryption key and a decryption key.
The SCS 51 transmits a registration completion response including the service ID to the MTC application server 52.

(2B) Mobile station registration and decryption key distribution phase (step S52)
The specific mobile station 400A requests the SCS 51 to subscribe to the message delivery service.
The SCS 51 associates the identifier of the specific mobile station 400A with the message delivery service (for example, for billing).
-SCS51 transmits service ID, message ID (for example, WTV), and a decryption key to the specific mobile station 400A.
The specific mobile station 400A manages the service ID, the message ID (for example, WTV), and the decryption key in association with each other.

(2C) Message distribution phase (step S53)
The MTC application server 52 transmits a broadcast request (including a service ID, a message to be distributed, a distribution policy, etc.) to the SCS 51.
-SCS encrypts the message with the encryption key corresponding to the service ID.
The SCS 51 transmits a broadcast request (including service ID, encrypted message, distribution policy, etc.) to the MTC-IWF entity 16.
The MTC-IWF entity 16 transmits a broadcast request (including a message ID (eg, WTV), an encrypted message, a distribution policy, etc.) to the broadcast node (CBC) 100.
The broadcast node (CBC) 100 requests the control node (MME) 200 that manages the distribution area specified based on the distribution policy to transmit the encrypted message by cell broadcast.
The control node (MME) 200 requests the cell broadcast of the encrypted message from the base station (eNodeB) 300.
The specific mobile station 400A receives the cell broadcast information in the cell 310, and decrypts and uses the encrypted message.
The other mobile station 400B that is not registered in the message distribution service discards the broadcast information in which the WTV that is not managed by the mobile station 400B is specified. The other mobile station 400B may discard the encrypted message in response to the inability to decrypt the encrypted message.

<Pattern 3>
In pattern 3, the MTC-IWF entity 16 is responsible for generating encryption keys and decryption keys and encrypting messages. Distribution of the decryption key to the specific mobile station 400A is performed via the control plane. Pattern 3 includes the processes listed in the following (3A) to (3C). Note that the processing in phase (3C) is the same as the processing in phase (1C) described above.

(3A) Message distribution service registration phase (step S51)
The MTC application server 52 requests a message delivery service from the SCS 51.
-SCS51 produces | generates the service ID matched with the new message delivery service.
The SCS 51 transmits a service registration request including the service ID to the MTC-IWF entity 16.
The MTC-IWF entity 16 requests a message ID (for example, Warning Type Value (WTV)) from the broadcast node (CBC) 100.
The broadcast node (CBC) 100 assigns a free message ID (for example, WTV), and notifies the MTC-IWF entity 16 of the assigned message ID.
The MTC-IWF entity 16 generates an encryption key and a decryption key corresponding to the service ID and message ID (for example, WTV) (the encryption key and the decryption key may be the same. Necessary for generating the encryption key and the decryption key) Code may be generated.)
The MTC-IWF entity 16 associates and manages an encryption key and a decryption key corresponding to a service ID and a message ID (for example, WTV).
The MTC-IWF entity 16 transmits a service ID, a message ID (for example, WTV), and a decryption key to the subscriber information server (HSS) 209 (transmission of the encryption key is not necessary).
The subscriber information server (HSS) 209 manages a service ID, a message ID (for example, WTV), and a decryption key in association with each other.
The MTC-IWF entity 16 transmits a registration completion response including the service ID to the SCS 51.
The SCS 51 transmits a registration completion response including the service ID to the MTC application server 52.

(3B) Mobile station registration and decryption key distribution phase (step S52)
The control node (MME) 200 requests a message ID (for example, WTV) and a decryption key from the subscriber information server (HSS) 209 at the time of the attach request or service request of the specific mobile station 400A.
The subscriber information server (HSS) 209 determines that the specific mobile station 400A is a subscriber of the message distribution service, and a message ID corresponding to the message distribution service permitted to be used by the specific mobile station 400A (for example, , WTV) and the decryption key are transmitted to the control node (MME) 200.
The control node (MME) 200 transmits a message ID (for example, WTV) and a decryption key to the specific mobile station 400A in response to an attach request or a service request.
The specific mobile station 400A manages the message ID (for example, WTV) and the decryption key in association with each other.

(3C) Message distribution phase (step S53)
The MTC application server 52 transmits a broadcast request (including a service ID, a message to be distributed, a distribution policy, etc.) to the SCS 51.
The SCS 51 sends a broadcast request (including service ID, message to be distributed, distribution policy, etc.) to the MTC-IWF entity 16.
The MTC-IWF entity 16 encrypts the message with the encryption key corresponding to the service ID included in the broadcast request.
The MTC-IWF entity 16 transmits a broadcast request (including a message ID (eg, WTV), an encrypted message, a distribution policy, etc.) to the broadcast node (CBC) 100.
The broadcast node (CBC) 100 requests the control node (MME) 200 that manages the distribution area specified based on the distribution policy to transmit the encrypted message by cell broadcast.
The control node (MME) 200 requests the cell broadcast of the encrypted message from the base station (eNodeB) 300.
The specific mobile station 400A receives the cell broadcast information in the cell 310, and decrypts and uses the encrypted message.
The other mobile station 400B that is not registered in the message distribution service discards the broadcast information in which the WTV that is not managed by the mobile station 400B is specified. The other mobile station 400B may discard the encrypted message in response to the inability to decrypt the encrypted message.

<Pattern 4>
In pattern 2, the SCS 51 is responsible for generating the encryption key and decryption key and encrypting the message. Distribution of the decryption key to the specific mobile station 400A is performed via the control plane. The pattern 4 includes the processes listed in the following (4A) to (4C). The process in phase (4B) is the same as the process in phase (3B) described above. Further, the processing in phase (4C) is the same as the processing in phase (2C) described above.

(4A) Message distribution service registration phase (step S51)
The MTC application server 52 requests a message delivery service from the SCS 51.
-SCS51 produces | generates the service ID matched with the new message delivery service.
The SCS 51 transmits a service registration request including the service ID to the MTC-IWF entity 16.
The MTC-IWF entity 16 requests a message ID (for example, Warning Type Value (WTV)) from the broadcast node (CBC) 100.
The broadcast node (CBC) 100 assigns a free message ID (for example, WTV), and notifies the MTC-IWF entity 16 of the assigned message ID.
The MTC-IWF entity 16 manages the service ID and the message ID (for example, WTV) in association with each other.
The MTC-IWF entity 16 transmits a message ID (for example, WTV) to the SCS 51.
-The SCS 51 generates an encryption key and a decryption key corresponding to the service ID and message ID (for example, WTV). (The encryption key and the decryption key may be the same. The code necessary for generating the encryption key and the decryption key is generated. May be.)
The SCS 51 associates and manages a service ID, a message ID (for example, WTV), and an encryption key and a decryption key.
The SCS 51 transmits a service ID (for example, WTV) and a decryption key to the MTC-IWF entity 16.
The MTC-IWF entity 16 transmits a service ID, a message ID (for example, WTV), and a decryption key to the subscriber information server (HSS) 209 (transmission of the encryption key is unnecessary).
The subscriber information server (HSS) 209 manages a service ID, a message ID (for example, WTV), and a decryption key in association with each other.
The MTC-IWF entity 16 transmits a registration completion response including the service ID to the SCS 51.
The SCS 51 transmits a registration completion response including the service ID to the MTC application server 52.

(4B) Mobile station registration and decryption key distribution phase (step S52)
The control node (MME) 200 requests a message ID (for example, WTV) and a decryption key from the subscriber information server (HSS) 209 at the time of the attach request or service request of the specific mobile station 400A.
The subscriber information server (HSS) 209 determines that the specific mobile station 400A is a subscriber of the message distribution service, and a message ID corresponding to the message distribution service permitted to be used by the specific mobile station 400A (for example, , WTV) and the decryption key are transmitted to the control node (MME) 200.
The control node (MME) 200 transmits a message ID (for example, WTV) and a decryption key to the specific mobile station 400A in response to an attach request or a service request.
The specific mobile station 400A manages the message ID (for example, WTV) and the decryption key in association with each other.

(4C) Message distribution phase (step S53)
The MTC application server 52 transmits a broadcast request (including a service ID, a message to be distributed, a distribution policy, etc.) to the SCS 51.
-SCS encrypts the message with the encryption key corresponding to the service ID.
The SCS 51 transmits a broadcast request (including service ID, encrypted message, distribution policy, etc.) to the MTC-IWF entity 16.
The MTC-IWF entity 16 transmits a broadcast request (including a message ID (eg, WTV), an encrypted message, a distribution policy, etc.) to the broadcast node (CBC) 100.
The broadcast node (CBC) 100 requests the control node (MME) 200 that manages the distribution area specified based on the distribution policy to transmit the encrypted message by cell broadcast.
The control node (MME) 200 requests the cell broadcast of the encrypted message from the base station (eNodeB) 300.
The specific mobile station 400A receives the cell broadcast information in the cell 310, and decrypts and uses the encrypted message.
The other mobile station 400B that is not registered in the message distribution service discards the broadcast information in which the WTV that is not managed by the mobile station 400B is specified. The other mobile station 400B may discard the encrypted message in response to the inability to decrypt the encrypted message.

  It should be noted that the procedure shown in FIG. 12 and the procedures according to patterns 1 to 4 are merely examples. For example, the procedure for registering a new message delivery service in step S51 may be omitted. A plurality of message delivery services may use the same message ID (for example, Message Identifier of CBS Message or WTV). A plurality of message delivery services that use the same message ID may use different encryption keys and decryption keys for each delivery service. Thereby, the independence between message delivery services is ensured.

  Also, registration of the specific mobile station 400A that receives the message distribution service corresponding to step S52 and distribution of the decryption key to the specific mobile station 400A are performed in the user plane between the MTC application server 52 and the specific mobile station 400A. Also good. In this case, in order to transmit the decryption key, a secure transmission path (for example, a transmission path using Secure Socket Layer (SSL) or Transport Layer Security (TLS)) between the MTC application server 52 and the specific mobile station 400A. May be used.

<Third Embodiment>
In the present embodiment, modifications of the first and second embodiments will be described. The first and second embodiments use message encryption so that the mobile station 400 that should use (or discard) the content contained in the cell broadcast information can be specified with fine granularity. An example is shown. In the first and second embodiments, it can be said that the specific mobile station 400A has a privilege to receive a restricted message. In other words, it can be said that the decryption key held in the specific mobile station 400A is a privilege granted to the specific mobile station 400A from the network to permit the restricted message. There is an advantage that the use of the message can be surely limited to only the specific mobile station 400A by giving the decryption key to the specific mobile station 400A instead of simply granting the privilege (authority). This is because the other mobile station 400B that does not have the privilege (that is, the decryption key) cannot decrypt the message.

  However, in order to be able to specify the mobile station 400 that should use (or discard) the content included in the cell broadcast information with a fine granularity, it is simply a privilege (permitted to allow limited message reception) ( (Authority) may only be given to the specific mobile station 400A. In this case, the message transmitted in the broadcast information does not need to be encrypted. The specific mobile station 400A to which the privilege is granted receives the cell broadcast information and uses the restricted message included in the cell broadcast information. On the other hand, the other mobile station 400B to which the privilege is not granted receives the cell broadcast information and discards the restricted message. In the present embodiment, an example in which the mobile station 400 that should use (or discard) the content included in the cell broadcast information according to the presence / absence of the privilege is shown.

  FIG. 13 is a block diagram illustrating a configuration example of the cellular communication system 2 according to the present embodiment. The configuration example of FIG. 13 is the same as the configuration example of the first embodiment shown in FIG. That is, the cellular communication system 2 includes a plurality of mobile stations (User Equipment (UE)) 2400, a message distribution system 2500, and a cellular communication network 210. The cellular communication network 210 performs cell broadcast of cell broadcast information. The cellular communication network 210 includes a broadcast node 2100, a control node 2200, and a base station 2300.

  Message distribution system 2500 corresponds to Cell Broadcast Entity (CBE) and transmits a broadcast request to cellular communication network 210. In the present embodiment, the broadcast request includes a message restricted for the specific mobile station 2400A. The broadcast request may include a display indicating that the message is a restricted message (hereinafter, restricted display). Note that if the message delivery system 2500 is a system specialized for sending restricted messages, the broadcast request need not include an indication indicating that the message is a restricted message. This is because the broadcast node 2100 can determine whether or not it is a broadcast of a restricted message by the broadcast request transmission source system.

  Broadcast node 2100 sends a broadcast request including a restricted message and a restriction indication to control node 2200. The control node 2200 determines the base station 2300 to perform cell broadcast based on the distribution area information, and requests the target base station 2300 to perform cell broadcast of the restricted message. In response to receiving the broadcast request, the base station 2300 broadcasts the cell broadcast information including the restricted message and the restriction indication in the cell 2310 so that the plurality of mobile stations 2400 can receive it.

  Each of a plurality of mobile stations (UEs) 2400 receives broadcast information including a restricted message in cell 2310. Among the plurality of mobile stations 2400, the specific mobile station 2400A has a privilege (privileged data) and is allowed to use a restricted message. Since the other mobile station 2400B is not given a privilege (privileged data), use of the restricted message included in the broadcast information is prohibited. Therefore, the other mobile station 2400B may discard the broadcast information including the restricted message or the restricted message included in the broadcast information.

  The restriction display included in the cell broadcast information may be a specific identifier (for example, a specific Message Identifier in the CBS message) of the cell broadcast information assigned to each message delivery service. Further, for example, the restriction display may be included in the cell broadcast information as content together with the restricted message.

  The privilege (privilege data) for permitting the use of the restricted message may be stored in advance in a USIM or the like installed in the specific mobile station 2400. In addition, the message delivery system 2500 or another node may grant a privilege to the specific mobile station 2400 in communication via the user plane or the control plane.

  FIG. 14 is a sequence diagram illustrating an example of a procedure for distributing cell broadcast information including a restricted message and a restriction display. FIG. 14 shows a case where the cellular communication system 1 is EPS.

  In step S61, the message delivery system 2500 (eg, CBE) transmits a broadcast request including the restricted message to the broadcast node 2100 (eg, CBC). In step S62, the broadcast node 2100 transmits a Write-Replace Warning Request message including the restricted message to the control node 2200 (for example, MME). In step S63, the control node 2200 selects the base station 2300 to perform cell broadcast, and transmits a Write-Replace Warning Request message including the restricted message and the restriction indication to the selected base station 2300. In step S64, the base station 2300 broadcasts in the cell 2310 cell broadcast information including a restricted message and a restriction indication. The privileged specific mobile station 2400A receives the cell broadcast information and uses the restricted message (step S65). For example, the specific mobile station 2400A may present the restricted message to the user, or may control the operation of the specific mobile station 2400 according to the restricted message. On the other hand, the mobile station 2400B to which the privilege is not given receives the cell broadcast information, believes the restriction display, and discards the restricted message (step S66).

  The granting of privileges to the specific mobile station 2400A can be performed in the same procedure as the procedure for giving the decryption key to the specific mobile station 400A in the first and second embodiments. For example, similar to the procedure shown in FIG. 3 or FIG. 4, the specific mobile station 2400A may obtain privileges from the message distribution system 2500 or the subscriber information server in communication via the control plane or the user plane. Further, the specific mobile station 2400A may obtain a privilege not when transmitting an attach request message but when transmitting a bearer establishment request message, a service request message, or a location registration update request message.

  As can be understood from the above description, in the cellular communication system 2 of the present embodiment, the use of the content (message) included in the cell broadcast information is limited only to the specific mobile station 2400A to which privileges are given. That is, in the present embodiment, the mobile station 2400 that should use the content included in the cell broadcast information is limited to the specific mobile station 2400A to which privileges are given. For example, when a plurality of mobile stations 2400 receive cell broadcast information from the HPLMN common to them, only the specific mobile station 2400 to which privileges are given can use the content (restricted message). Therefore, according to this embodiment, the mobile station 2400 that should use (or discard) the content included in the cell broadcast information can be specified with a fine granularity using the presence or absence of privilege as an index.

<Other embodiments>
In the first to third embodiments, the specific examples in which the cellular communication system 1 is UMTS or EPS are shown. However, the application destinations of the first and second embodiments are not limited to the UMTS and EPS cellular communication systems. That is, the first and second embodiments are widely applicable to cellular communication systems that broadcast messages to a plurality of mobile stations in a cell.

  The processing of the message distribution system 500, the broadcast node 100, the control node 200, the base station 300, and the mobile station 400 described in the first to third embodiments is performed by at least one processor (eg, microprocessor, MPU (Micro It may be realized by causing a computer system including a processing unit (DSP) and a digital signal processor (DSP) to execute a program. Specifically, one or a plurality of programs including an instruction group for causing a computer system to execute an algorithm described using a flowchart, a sequence diagram, and the like may be created, and the programs may be supplied to the computer.

  This program can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W and semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  Furthermore, the above-described embodiment is merely an example relating to application of the technical idea obtained by the present inventors. That is, the technical idea is not limited to the above-described embodiment, and various changes can be made.

  The technical idea shown in the embodiment described above can be described as, for example, the following supplementary notes, but is not limited thereto.

(Appendix 1)
A control node;
A base station,
Multiple mobile stations,
With
The control node is configured to send a broadcast request including a message and a restriction indication to the base station;
The base station is configured to receive the broadcast request and broadcast in a cell so that the plurality of mobile stations can receive broadcast information including the message and a restriction indication;
Each of the plurality of mobile stations receives the broadcast information including the message and the restriction indication in the cell, and uses the message when the privilege corresponding to the restriction indication is granted, and the restriction indication Configured to discard the message if the privilege corresponding to is not granted,
Cellular communication system.
(Appendix 2)
Further comprising a message delivery system for supplying the encrypted message to the control node;
The mobile station is configured to obtain the privilege in communication with the message delivery system via a control plane or a user plane.
The cellular communication system according to attachment 1.
(Appendix 3)
The specific mobile station transmits a request for subscription to a message delivery service to the message delivery system,
In response to the subscription request, the message delivery system grants the privilege to the mobile station via a user plane.
The cellular communication system according to attachment 2.
(Appendix 4)
A subscriber information server for managing subscriber information of the plurality of mobile stations;
The mobile station is configured to obtain the privilege via a control plane including the subscriber information server.
The cellular communication system according to appendix 1 or 2.
(Appendix 5)
The mobile station includes a Machine Type Communication (MTC) device,
The message delivery system includes at least one of MTC Interworking Function (MTC-IWF), Service Capability Server, and MTC Application Server (AS).
The cellular communication system according to Supplementary Note 2, Supplementary Note 3, or Supplementary Note 4 that cites Supplementary Note 2.

(Appendix 6)
A mobile station,
A wireless communication unit for receiving broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive the data;
A message processing unit for processing a message included in the broadcast information;
With
The broadcast information includes the message and a restriction indication;
The message processing unit uses the message when a privilege corresponding to the restriction indication is given to the mobile station, and when the privilege corresponding to the restriction indication is not given to the mobile station, Discard the message,
Mobile station.
(Appendix 7)
The mobile station according to appendix 6 or 7, wherein the message processing unit obtains the privilege in communication via a control plane or a user plane with a message distribution system that supplies the message to a cellular communication network including the base station.
(Appendix 8)
The message processing unit transmits a request for subscription to a message distribution service to the message distribution system;
The message processing unit obtains the privilege from the message delivery system via a user plane;
The mobile station according to appendix 7.
(Appendix 9)
The mobile station according to appendix 6 or 7, wherein the message processing unit obtains the privilege via a control plane including a subscriber information server that manages subscriber information of the plurality of mobile stations.

(Appendix 10)
A transmitter for broadcasting in a cell so that a plurality of mobile stations can receive broadcast information including a message and a restriction indication;
The restriction indication causes the message to be discarded in a mobile station that is not given a privilege corresponding to the restriction indication among the plurality of mobile stations.
base station.

(Appendix 11)
A method performed in a mobile station,
Receiving broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive, and processing a message included in the broadcast information;
With
The broadcast information includes the message and a restriction indication;
The processing uses the message when a privilege corresponding to the restriction indication is given to the mobile station, and uses the message when the privilege corresponding to the restriction indication is not given to the mobile station. Including discarding the message,
Method.

(Appendix 12)
A method performed in a base station,
Broadcasting in a cell so that a plurality of mobile stations can receive broadcast information including messages and restriction indications,
The restriction indication causes the message to be discarded in a mobile station that is not given a privilege corresponding to the restriction indication among the plurality of mobile stations.
Method.

(Appendix 13)
A non-transitory computer-readable medium storing a program for causing a computer to perform a method related to a mobile station,
The method includes processing a message included in broadcast information broadcast in a cell from a base station for reception by a plurality of mobile stations;
The broadcast information includes the message and a restriction indication;
The processing uses the message when a privilege corresponding to the restriction indication is given to the mobile station, and uses the message when the privilege corresponding to the restriction indication is not given to the mobile station. Including discarding the message,
A non-transitory computer readable medium.

(Appendix 14)
A non-transitory computer-readable medium storing a program for causing a computer to perform a method related to a base station,
The method includes controlling the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including a message and a restriction indication;
The restriction indication causes the message to be discarded in a mobile station that is not given a privilege corresponding to the restriction indication among the plurality of mobile stations.
A non-transitory computer readable medium.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2013-079965 for which it applied on April 5, 2013, and takes in those the indications of all here.

1 Cellular Communication System 10 Cellular Communication Network 13 Charging Data Function / Charging Gateway Function (CDF / CGF)
15 Radio Access Network (RAN)
16 Machine Type Communication Inter Working Function (MTC-IWF) entity 17 Serving Gateway (S-GW)
18 Packet Data Network Gateway (P-GW)
51 Service Capability Server (SCS)
52 MTC Application Server (AS)
100 broadcast node 101 distribution request unit 200 control node 201 distribution request unit 209 subscriber information server 300 base station 301 wireless communication unit 302 broadcast unit 310 cell 400, 400A, 400B mobile station 401 wireless communication unit 410 MTC UE application 402 message processing unit 500 Message Distribution System 501 Distribution Control Unit

Claims (42)

A control node;
A base station,
Multiple mobile stations,
With
The control node is configured to send a broadcast request including an encrypted message to the base station;
The base station is configured to receive the broadcast request and broadcast in a cell so that the plurality of mobile stations can receive broadcast information including the encrypted message;
Each of the plurality of mobile stations is configured to receive the broadcast information including the encrypted message in the cell;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Cellular communication system.   The cellular communication system according to claim 1, wherein each of the plurality of mobile stations is configured to discard the encrypted message when it does not hold the decryption key. Further comprising a message delivery system for supplying the encrypted message to the control node;
The specific mobile station receives the decryption key or a code necessary for generating the decryption key from the message distribution system via a control plane or a user plane.
The cellular communication system according to claim 1 or 2. The specific mobile station transmits a request for subscription to a message delivery service to the message delivery system,
In response to the subscription request, the message delivery system transmits the decryption key or the code to the specific mobile station via a user plane.
The cellular communication system according to claim 3. A subscriber information server for managing subscriber information of the plurality of mobile stations;
The specific mobile station receives the decryption key or a code necessary for generating the decryption key via a control plane including the subscriber information server.
The cellular communication system according to any one of claims 1 to 3. The specific mobile station includes a Machine Type Communication (MTC) device,
The message delivery system includes at least one of MTC Interworking Function (MTC-IWF), Service Capability Server, and MTC Application Server (AS).
The cellular communication system according to claim 5, wherein the cellular communication system is cited.   The cellular node according to any one of claims 1 to 6, wherein the control node is configured to select a target base station from among a plurality of base stations, and to transmit the broadcast request to the target base station. Communications system.   The cellular communication system according to claim 7, wherein the control node is configured to receive distribution area information of the encrypted message and select the target base station using the distribution area information.   The cellular communication system according to any one of claims 1 to 8, wherein the broadcast information is a CBS message broadcast from the base station according to a Cell Broadcast Service (CBS) of a Third Generation Partnership Project (3GPP).   The cellular communication system according to any one of claims 1 to 9, wherein the control node is a cell broadcast center (CBC), a mobility management entity (MME), or a radio network controller (RNC). A mobile station,
Wireless communication means for receiving broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive the data;
Message processing means for processing an encrypted message included in the broadcast information;
With
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Mobile station.   The mobile station according to claim 11, wherein the message processing unit discards the encrypted message when the decryption key is not held.   The message processing means is necessary for generating the decryption key or the decryption key from a message distribution system that supplies the encrypted message to a cellular communication network including the base station via a control plane or a user plane. The mobile station according to claim 11 or 12, which receives a code. The message processing means transmits a request for subscription to a message distribution service to the message distribution system;
The message processing means receives the decryption key or the code transmitted from the message delivery system via a user plane in response to the subscription request;
The mobile station according to claim 13.   12. The message processing means receives the decryption key or a code necessary for generating the decryption key via a control plane including a subscriber information server that manages subscriber information of the plurality of mobile stations. The mobile station of any one of -13. The message delivery system includes at least one of MTC Interworking Function (MTC-IWF), Service Capability Server, and MTC Application Server (AS).
The mobile station according to claim 13, claim 14, or claim 15 quoting claim 13.   The mobile station according to any one of claims 11 to 16, wherein the broadcast information includes the encrypted message and non-encrypted incidental information that can be processed by the plurality of mobile stations. .   The mobile station according to any one of claims 11 to 17, wherein the broadcast information is a CBS message broadcast from the base station according to a Cell Broadcast Service (CBS) of a Third Generation Partnership Project (3GPP). Transmitting means for broadcasting in a cell so that a plurality of mobile stations can receive broadcast information including an encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
base station.   The base station according to claim 19, wherein the transmission unit receives a broadcast request including the encrypted message from a control node.   The base station according to claim 19 or 20, wherein the broadcast information includes the encrypted message and non-encrypted incidental information that can be processed by the plurality of mobile stations.   The base station according to any one of claims 19 to 21, wherein the broadcast information is a CBS message broadcast from the base station according to a Cell Broadcast Service (CBS) of a Third Generation Partnership Project (3GPP). Control means for transmitting a broadcast request including an encrypted message to the base station;
The broadcast request causes the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Control node.   The control node according to claim 23, wherein the control means transmits the decryption key or a code necessary for generating the decryption key to the specific mobile station.   The control node according to claim 24, wherein the control means receives the decryption key or the code to be transmitted to the specific mobile station from a subscriber information server that manages subscriber information of the plurality of mobile stations.   The control node according to any one of claims 23 to 25, wherein the control unit selects a target base station from a plurality of base stations and transmits the broadcast request to the target base station.   27. The control node according to claim 26, wherein the control means receives distribution area information of the encrypted message and selects the target base station using the distribution area information.   The control node according to any one of claims 23 to 27, wherein the broadcast information is a CBS message broadcast from the base station according to a Cell Broadcast Service (CBS) of a Third Generation Partnership Project (3GPP).   The control node according to any one of claims 23 to 28, wherein the control node is a Cell Broadcast Center (CBC), a Mobility Management Entity (MME), or a Radio Network Controller (RNC). A delivery control means for transmitting a broadcast request including an encrypted message to a cellular communication network;
The broadcast request causes the cellular communication network to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Message delivery system.   31. The message delivery system according to claim 30, further comprising management means for transmitting the decryption key or a code necessary for generating the decryption key to the specific mobile station via a control plane or a user plane.   The distribution control means receives a request for subscription to a message distribution service from the specific mobile station, and transmits the decryption key or the code to the specific mobile station via a user plane in response to the subscription request. The message delivery system according to claim 31. The specific mobile station includes a Machine Type Communication (MTC) device,
The message delivery system includes at least one of MTC Interworking Function (MTC-IWF), Service Capability Server, and MTC Application Server (AS).
The message delivery system according to claim 31 or 32.   The message distribution system according to any one of claims 30 to 33, wherein the broadcast information is a CBS message broadcast according to a Cell Broadcast Service (CBS) of a Third Generation Partnership Project (3GPP). A method performed in a mobile station,
Receiving broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive, and processing an encrypted message included in the broadcast information;
With
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Method. A method performed in a base station,
Broadcasting in a cell so that a plurality of mobile stations can receive broadcast information including an encrypted message,
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Method. A method performed in a control node,
Sending a broadcast request including an encrypted message to a base station;
The broadcast request causes the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Method. A method performed in a message delivery system,
Sending a broadcast request including an encrypted message to a cellular communication network;
The broadcast request causes the cellular communication network to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
Method. A non-transitory computer-readable medium storing a program for causing a computer to perform a control method related to a mobile station,
The control method includes processing an encrypted message included in broadcast information broadcast in a cell from a base station so that a plurality of mobile stations can receive it,
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
A non-transitory computer readable medium. A non-transitory computer-readable medium storing a program for causing a computer to perform a control method related to a base station,
The control method includes controlling the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including an encrypted message,
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
A non-transitory computer readable medium. A non-transitory computer-readable medium storing a program for causing a computer to perform a control method related to a control node,
The control method includes controlling the control node to transmit a broadcast request including an encrypted message to a base station;
The broadcast request causes the base station to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
A non-transitory computer readable medium. A non-transitory computer-readable medium storing a program for causing a computer to perform a control method related to a message delivery system,
The control method includes controlling the message delivery system to send a broadcast request including an encrypted message to a cellular communication network;
The broadcast request causes the cellular communication network to broadcast in a cell so that a plurality of mobile stations can receive broadcast information including the encrypted message;
The encrypted message is encrypted so that it can be decrypted by a decryption key held only in at least one specific mobile station among the plurality of mobile stations.
A non-transitory computer readable medium.

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