Patent Publication Number: US-2023156469-A1

Title: Wireless communication apparatus and server apparatus

Description:
RELATED APPLICATIONS 
     The present application is a continuation based on PCT Application No. PCT/JP2021/027420, filed on Jul. 21, 2021, which claims the benefit of Japanese Patent Application No. 2020-127747 filed on Jul. 28, 2020. The content of which is incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a wireless communication apparatus and a server apparatus. 
     BACKGROUND OF INVENTION 
     In order for a wireless communication apparatus to receive a cellular communication service from a communication operator, Subscriber Identity Module (SIM) information (e.g., an International Mobile Subscriber Identity (IMSI)) corresponding to the communication operator is required. 
     In recent years, a SIM management apparatus is widely used that manages a plurality of pieces of SIM information, each of which corresponds to a respective one of a plurality of communication operators. 
     The wireless communication apparatus acquires, from the SIM management apparatus, the SIM information appropriate for the wireless communication apparatus itself (e.g., SIM information corresponding to a communication operator at a location of the wireless communication apparatus) and stores the SIM information in a storage. The wireless communication apparatus uses the stored SIM information to receive a cellular communication service from a communication operator corresponding to the SIM information (e.g., see Patent Literature 1). 
     Citation List 
     Patent Literature 
     Patent Literature 1: JP 2013-505658 T 
     SUMMARY 
     In a first aspect, a wireless communication apparatus includes a storage, a communicator configured to perform wireless communication with a cellular network, and a controller configured to establish a first wireless connection with the cellular network when available Subscriber Identity Module (SIM) information is not stored in the storage, the first wireless connection being an unencrypted connection. The communicator is configured to transmit predetermined information to the cellular network through the first wireless connection, the predetermined information being used to establish a second wireless connection with the cellular network, and the second wireless connection being an encrypted connection. The controller is configured to, after the first wireless connection is released, establish the second wireless connection with the cellular network by using the predetermined information. The communicator is configured to receive the available SIM information through the second wireless connection. 
     In a second aspect, a server apparatus includes a communicator configured to receive, from a wireless communication apparatus, predetermined information used to establish an encrypted wireless connection between the wireless communication apparatus and a cellular network, through an unencrypted wireless connection between the wireless communication apparatus and the cellular network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram illustrating a configuration of a mobile communication system according to an embodiment. 
         FIG.  2    is a diagram illustrating a configuration of a wireless communication apparatus  100  according to an embodiment. 
         FIG.  3    is a diagram illustrating a configuration of a base station  200  according to an embodiment. 
         FIG.  4    is a diagram illustrating a configuration of a core network apparatus  400  according to an embodiment. 
         FIG.  5    is a diagram illustrating a configuration of a server apparatus  300  according to an embodiment. 
         FIG.  6    is a diagram illustrating an operation example of a mobile communication system according to an embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     When a wireless communication apparatus acquires SIM information from a SIM management apparatus, a wireless communication means for accessing the SIM management apparatus is required. In particular, when a storage of the wireless communication apparatus includes no SIM information, such a wireless communication means needs to be provided separately, which problematically leads to inefficiency. 
     In view of this, the object of the present disclosure is to efficiently acquire the SIM information from the SIM management apparatus. 
     A cellular communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference signs. 
     Configuration of Mobile Communication System 
       FIG.  1    is a diagram illustrating a configuration of a mobile communication system 1 according to an embodiment. 
     As illustrated in  FIG.  1   , the mobile communication system 1 includes a wireless communication apparatus  100 , a SIM management apparatus  600 , and a cellular network  10 . 
     The wireless communication apparatus  100  may be any wireless communication apparatus, such as a communication module, an IoT apparatus, a mobile phone, a smartphone, and a personal computer. 
     The SIM management apparatus  600  manages a plurality of pieces of SIM information, each of which corresponds to a respective one of a plurality of different communication operators. The SIM information is information stored in a SIM card issued by the communication operator. The SIM information includes subscriber identification information for identifying a subscriber, operator identification information for identifying a communication operator, and contract information related to available services to which a subscriber has subscribed. The subscriber identification information is, for example, an International Mobile Subscriber Identity (IMSI). 
     The SIM management apparatus  600  transmits, to the wireless communication apparatus  100 , the SIM information appropriate for the wireless communication apparatus  100  in response to a request from the wireless communication apparatus  100 . 
     For example, the SIM management apparatus  600  manages X SIM cards corresponding to a communication operator A of a country A, Y SIM cards corresponding to a communication operator B of a country B, and Z SIM cards corresponding to a communication operator C of a country C. The SIM management apparatus  600  stores pieces of SIM information, each of which corresponds to a respective one of these SIM cards. The SIM management apparatus  600  transmits, to the wireless communication apparatus  100 , the SIM information corresponding to one SIM card of X SIM cards corresponding to the communication operator A, in response to receiving a request message including information indicating that the wireless communication apparatus  100  is in the country A. 
     The SIM management apparatus  600  communicates with the cellular network  10  via another network (e.g., the Internet). 
     The cellular network  10  may support any mobile communication scheme including the second generation mobile communication scheme such as Global System for Mobile communications (GSM) (trade name), the third generation mobile communication scheme such as Code Division Multiple Access (CDMA), the fourth generation mobile communication scheme such as Long Term Evolution (LTE), and further the fifth generation mobile communication scheme. Such a mobile communication scheme may be referred to as Radio Access Technology (RAT). The fifth generation mobile communication scheme may be referred to as New RAT (NR). Such a mobile communication scheme may be a mobile communication scheme defined by a standardization entity. The standardization entity may be the 3rd Generation Partnership Project (3GPP), the Institute of Electrical and Electronics Engineers (IEEE), or the like. 
     The cellular network  10  includes a base station  200 , a server apparatus  300 , a core network apparatus  400 , and an authentication apparatus  500 . 
     The base station  200  provides a mobile communication service in a coverage area of the base station  200  by using at least one of the above-described mobile communication schemes. Such a coverage area may be referred to as a “cell”. The base station  200  manages one or more cells. 
     The core network apparatus  400  performs location management of the wireless communication apparatus  100 , subscriber authentication, security, and the like. An example of the core network apparatus is a Mobility Management Entity (MME) or an Access and Mobility Management Function (AMF). 
     The authentication apparatus  500  includes a subscriber database in which the subscriber identification information of the subscriber and a shared key corresponding to the subscriber are associated with each other, and stored, the subscriber having a contract with the communication operator managing the cellular network  10 . The SIM information held by the wireless communication apparatus  100  includes the subscriber identification information and the shared key. The shared key may be referred to as a K value. 
     The authentication apparatus  500  performs a shared key based authentication procedure on the wireless communication apparatus  100  accessing the cellular network  10 . This encrypts a wireless connection between the wireless communication apparatus  100  and the cellular network  10 . 
     The authentication procedure is a procedure for verifying the consistency between the shared key on the wireless communication apparatus  100  side and the shared key on the authentication apparatus  500  side. An example of such an authentication procedure is an Authentication and Key Agreement (AKA) procedure defined in the 3GPP. The AKA procedure is as follows. 
     Firstly, the core network apparatus  400  in the cellular network  10  acquires the subscriber identification information from the wireless communication apparatus  100 , and transmits an authentication data request message including the subscriber identification information to the authentication apparatus  500 . 
     Secondly, the authentication apparatus  500  refers to the subscriber database to identify the shared key to be associated with the received subscriber identification information, and calculates an expected response value by applying an algorithm to the shared key. The authentication apparatus  500  transmits, to the core network apparatus  400 , an authentication data response message including the expected response value and algorithm information indicating the algorithm. 
     Thirdly, the core network apparatus  400  transmits a user authentication request message including the algorithm information to the wireless communication apparatus  100 . 
     Fourthly, the wireless communication apparatus  100  calculates a response value by applying, to the shared key, an algorithm same as, and/or similar to, the algorithm applied by the authentication apparatus  500  regarding the algorithm, and transmits a user authentication response message including the response value to base station  200 . 
     Fifthly, the core network apparatus  400  compares the expected response value with the response value and determines that the authentication procedure is successful if the expected value is the same as, and/or similar to the response value. 
     In response to the success of the authentication procedure, a wireless communication between the wireless communication apparatus  100  and the cellular network  10  is encrypted. This allows the wireless communication apparatus  100  to receive cellular communication services from the cellular network  10 . 
     The server apparatus  300  performs each process related to the shared key described below. 
     Configuration of Wireless Communication Apparatus 
       FIG.  2    is a diagram illustrating a configuration of the wireless communication apparatus  100  according to an embodiment. 
     As illustrated in  FIG.  2   , the wireless communication apparatus  100  includes an antenna  110 , a communicator  120 , a controller  130 , and a storage  140 . 
     The antenna  110  transmits and receives radio signals to and from the base station  200 . The communicator  120  performs wireless communication with the base station  200  via the antenna  110 . 
     The communicator  120  supports at least one of the above-described mobile communication schemes. The communicator  120  receives the SIM information from the SIM management apparatus  600  through the wireless communication. 
     The controller  130  performs various types of processing and control in the wireless communication apparatus  100 . The controller  130  includes at least one processor. The processor may include a baseband processor and a Central Processing Unit (CPU). The baseband processor performs modulation and demodulation, coding and decoding, and the like of a baseband signal. The CPU performs various types of processing by executing programs stored in the storage  140 . The controller  130  stores the SIM information received by the communicator  120  in the storage  140 . 
     The storage  140  stores the programs to be executed by the controller  130 , and information and data to be used for the processing by the controller  130 . The storage  140  includes a volatile memory and a non-volatile memory. 
     The storage  140  includes a SIM information region provided to store the SIM information received by the communicator  120 . The non-volatile memory includes the SIM information region. 
     The controller  130  receives the cellular communication service from the communication operator corresponding to the SIM information by using the SIM information stored in the SIM information region. 
     When the SIM information is not stored in the SIM information region, the controller  130  is basically incapable of receiving the cellular communication service, but is capable of receiving some restricted cellular communication services. For example, when the SIM information is not stored in the SIM information region, the wireless communication apparatus  100  can establish an unencrypted wireless connection with the cellular network  10  as described below. 
     Base Station 
       FIG.  3    is a diagram illustrating a configuration of the base station  200  according to an embodiment. 
     As illustrated in  FIG.  3   , the base station  200  includes an antenna  210 , a communicator  220 , a controller  230 , a storage  240 , and a backhaul communicator  250 . 
     The antenna  210  transmits and receives radio signals to and from the wireless communication apparatus  100 . The communicator  220  performs wireless communication of the wireless communication apparatus  100  via the antenna  210 . 
     The communicator  220  supports at least one of the above-described mobile communication schemes. 
     The controller  230  performs various types of processing and control in the base station  200 . The controller  230  includes at least one processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation and demodulation, coding and decoding, and the like of a baseband signal. The CPU performs various types of processing by executing programs stored in the storage  240 . 
     The storage  240  stores the programs to be executed by the controller  230 , and information and data to be used for the processing by the controller  230 . 
     The backhaul communicator  250  is connected to the core network apparatus  400  via an interface between the base station and the core network. The backhaul communicator  250  is connected to a neighboring base station via an inter-base station interface. 
     Core Network Apparatus 
     The core network apparatus  400  according to an embodiment will be described.  FIG.  4    is a diagram illustrating a configuration of the core network apparatus  400  according to an embodiment. 
     As illustrated in  FIG.  4   , the core network apparatus  400  includes a controller  430 , a storage  440 , and a backhaul communicator  450 . 
     The controller  430  performs various types of processing and control in the core network apparatus  400 . The controller  430  includes at least one processor. 
     The storage  440  stores the programs to be executed by the controller  430 , and information and data to be used for the processing by the controller  430 . 
     The backhaul communicator  450  is connected to the base station  200  via the interface between the base station and the core network. 
     Server Apparatus 
     The server apparatus  300  according to an embodiment will be described.  FIG.  5    is a diagram illustrating a configuration of the server apparatus  300  according to an embodiment. 
     As illustrated in  FIG.  5   , the server apparatus  300  includes a controller  330 , a storage  340 , and a backhaul communicator  350 . 
     The controller  330  performs various types of processing and control in the server apparatus  300 . The controller  330  includes at least one processor. The processor executes the programs stored in the storage  340  to perform various types of processing. 
     The storage  340  stores the programs to be executed by the controller  330 , and information and data to be used for the processing by the controller  330 . 
     The backhaul communicator  350  is connected to each of the base station  200 , the core network apparatus  400 , and the authentication apparatus  500  via predetermined interfaces. 
     The wireless communication apparatus  100  configured as described above needs to access the SIM management apparatus  600  to acquire the available SIM information when the SIM information is not stored in the storage  140 , or when the SIM information stored in the storage  140  is not available. Here, “the SIM information is not available” means that the communication operator corresponding to the SIM information is not a communication operator in a region (country) where the wireless communication apparatus  100  is located, that the subscriber corresponding to SIM information has canceled the contract, and the like. 
     The wireless communication apparatus  100  needs to perform the authentication procedure with the cellular network  10  (authentication apparatus  500 ) to establish an encrypted wireless connection with the cellular network  10  in order to access the SIM management apparatus  600 . 
     However, since the wireless communication apparatus  100  does not hold the available SIM information (or the available SIM information is not stored in the storage  140 ), the wireless communication apparatus  100  does not have the shared key necessary to perform the authentication procedure, and cannot perform the authentication procedure. 
     The embodiment is an embodiment for solving such a problem. 
     In an embodiment, the wireless communication apparatus  100  transmits predetermined information for calculating the shared key to the server apparatus  300  in the cellular network  10  through a first wireless connection, which is unencrypted, with the cellular network  10 . The wireless communication apparatus  100  calculates the shared key based on the predetermined information. 
     The server apparatus  300  receives the predetermined information through the first wireless connection, and calculates the shared key based on the received predetermined information. The server apparatus  300  transmits the calculated shared key to the authentication apparatus  500 . The authentication apparatus  500  stores the shared key. 
     This allows the shared key to be shared between the wireless communication apparatus  100  and the authentication apparatus  500 . 
     The wireless communication apparatus  100  establishes a second wireless connection, which is encrypted, with the cellular network  10  by performing the shared key based authentication procedure with the authentication apparatus  500 . 
     The wireless communication apparatus  100  accesses the SIM management apparatus  600  through the second wireless connection and receives available SIM information from the SIM management apparatus  600 . 
     This allows the wireless communication apparatus  100 , which holds no available SIM information, to acquire available SIM information from the SIM management apparatus  600 . 
     The predetermined information is transmitted through the first wireless connection unencrypted, and may be intercepted by another wireless communication apparatus  100  (a wireless communication apparatus  100  which is not transmitting the predetermined information). Once having intercepted the predetermined information, another wireless communication apparatuses  100  can perform the shared key based authentication procedure, which negatively affects security of the cellular network  10 . 
     The server apparatus  300  sets a validity period for the shared key, and when the validity period expires, the server apparatus  300  transmits a request to delete the shared key to the authentication apparatus  500 . Thus, while the predetermined information is intercepted by another wireless communication apparatus  100 , the security of the cellular network  10  is not negatively affected after the validity period expires. 
     Operation Example 
       FIG.  6    is a diagram illustrating an operation example of a mobile communication system according to an embodiment. 
     In step S 101 , the wireless communication apparatus  100  (controller  130 ) determines whether the available SIM information is stored in the storage  140 . Here, when the SIM information is not stored in the storage  140  or the SIM information stored in the storage  140  is not available, the wireless communication apparatus  100  determines that the available SIM information is not stored in the storage  140 , and proceeds to the processing of step S 102 . 
     In step S 102 , the wireless communication apparatus  100  (controller  130 ) performs a connection procedure with the base station  200 , and establishes the first wireless connection. The first wireless connection is an unencrypted connection. For example, in the connection procedure, the wireless communication apparatus  100  notifies the base station  200  that the wireless communication apparatus  100  wants to establish a wireless connection for transmitting the predetermined information for generating the shared key. The base station  200  (core network apparatus  400 ) completes the connection procedure without performing the authentication procedure and establishes an unencrypted first wireless connection. 
     In step S 103 , the wireless communication apparatus  100  (communicator  120 ) transmits the predetermined information to the server apparatus  300 . 
     The predetermined information includes at least random number information indicating a random number calculated in the wireless communication apparatus  100 . The predetermined information may further include information indicating a time (current time) when the predetermined information is transmitted. The random number may have a format of IMSI. The random number having the format of IMSI may be used in the authentication procedure (the AKA procedure described above) as the temporary subscriber identification information of the wireless communication apparatus  100 . 
     In step S 104 , the wireless communication apparatus  100  (controller  130 ) calculates the shared key based on the predetermined information. 
     In step S 105 , the server apparatus  300  (controller  430 ) calculates the shared key based on the predetermined information. 
     Here, the wireless communication apparatus  100  and the server apparatus  300  calculate the shared key by applying the same algorithm to the predetermined information. Such an algorithm may be shared in advance between the wireless communication apparatus  100  and the server apparatus  300 . The server apparatus  300 , in response to receiving the predetermined information, may notify the wireless communication apparatus  100  of the algorithm. 
     In step S 106 , the wireless communication apparatus  100  (controller  130 ) stores the calculated shared key in the storage  140 . When the random number based on when the shared key is calculated has the format of IMSI, the wireless communication apparatus  100  stores the random number, as the subscriber identification information of the wireless communication apparatus  100 , in association with the shared key. 
     In step S 107 , the server apparatus  300  transmits the calculated shared key to the authentication apparatus  500 . When the random number based on when the shared key is calculated has the format of IMSI, the server apparatus  300  transmits the random number as the subscriber identification information of the wireless communication apparatus  100  together with the shared key. The server apparatus  300 , in response to transmitting the shared key, sets the validity period for the shared key, and starts a first timer having a first timer value equal to a length of the validity period. 
     In step S 108 , the authentication apparatus  500  stores the shared key. When the random number (subscriber identification information) is transmitted together with the shared key in step S 107 , the authentication apparatus  500  stores the shared key in association with the random number. 
     In accordance with the processing of steps S 102  to S 108 , the shared key is shared between the wireless communication apparatus  100  and the authentication apparatus  500 . 
     In step S 109 , the wireless communication apparatus  100  releases the first wireless connection. 
     In step S 110 , the wireless communication apparatus  100  establishes the second wireless connection (encrypted wireless connection) with the base station  200 . 
     Specifically, the wireless communication apparatus  100  performs the shared key based authentication procedure with the authentication apparatus  500  during the connection procedure with the base station  200 . This allows the second wireless connection encrypted to be established between the wireless communication apparatus  100  and the base station  200 . 
     Here, when the wireless communication apparatus  100  stores the subscriber identification information in step S 106 , the wireless communication apparatus  100  may perform the AKA procedure described above as the authentication procedure. 
     In step S 111 , the server apparatus  300  transmits a request to delete the shared key to the authentication apparatus  500 , in response to expiration of the first timer started in step S 107 . 
     In step S 112 , the authentication apparatus  500  deletes the shared key stored in step S 108 . 
     In step S 113 , the wireless communication apparatus  100  accesses the SIM management apparatus  600  through the second wireless connection to acquire the available SIM information from the SIM management apparatus  600 . The wireless communication apparatus  100  uses the acquired SIM information to receive the cellular communication service from the communication operator corresponding to the SIM information. 
     In the operation example described above, after the server apparatus  300  performs the processing in step S 107 , the server apparatus  300  may transmit information indicating a second timer value smaller than the first timer value to the wireless communication apparatus  100  through the first wireless connection. The wireless communication apparatus  100  starts the second timer having the second timer value in response to receiving the information, and performs the processing of step S 110  to step S 111  before the second timer expires. Accordingly, the wireless communication apparatus  100  can establish the second wireless connection before the shared key is deleted in the authentication apparatus  500 . 
     Other Embodiments 
     In the embodiment described above, the server apparatus  300  is separate from the base station  200 , but the server apparatus  300  and the base station  200  may constitute a single network apparatus. In this case, the processing performed by the server apparatus  300  in the above-described embodiment may be performed by the base station  200 . 
     In the embodiment described above, the server apparatus  300  is separate from the core network apparatus  400 , but the server apparatus  300  and the core network apparatus  400  may constitute a single network apparatus. In this case, the processing performed by the server apparatus  300  in the above-described embodiment may be performed by the core network apparatus  400 . 
     A program that causes a computer to execute each of the processing operations according to the embodiments described above may be provided. The program may be recorded in a computer readable medium. Use of the computer readable medium enables the program to be installed on a computer. Here, the computer readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. 
     Embodiments have been described above in detail with reference to the drawings, but specific configurations are not limited to those described above, and various design variation can be made without departing from the gist of the present disclosure. 
     Reference Signs 
     
         
         1: Mobile communication system 
           10 : Cellular network 
           100 : Wireless communication apparatus 
           110 : Antenna 
           120 : Communicator 
           130 : Controller 
           140 : Storage 
           200 : Base station 
           210 : Antenna 
           220 : Communicator 
           230 : Controller 
           240 : Storage 
           250 : Backhaul communicator 
           300 : Server apparatus 
           330 : Controller 
           340 : Storage 
           350 : Backhaul communicator 
           400 : Core network apparatus 
           430 : Controller 
           440 : Storage 
           450 : Backhaul communicator 
           450 : Backhaul communicator 
           600 : SIM management apparatus