Patent Publication Number: US-2009221296-A1

Title: Communication terminal, network server, and communication network system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a communication network system where a network server dynamically assigns a telephone number and a terminal identity to a communication terminal. 
     2. Description of Related Art 
       FIG. 6  shows a system for assigning a telephone number used in the current mobile communication system in Japan. As shown in  FIG. 6 , at least one eleven-digit telephone number formed of a three-digit service identification number “XXX” (“090” or “080”) and an eight-digit subscriber number “YYYYYYYY” is fixedly assigned to a mobile phone terminal. 
     Moreover, although not illustrated, a mobile station identity (MSI, which may hereinafter be referred to as a terminal identity) represented as the finite number of digits is fixedly assigned to a mobile phone terminal. Use of the mobile station identity enables a network server to determine (verify) whether or not a mobile phone terminal is under official contract even when a subscriber has changed mobile network operators by using a mobile number portability (MNP) service. 
     Since a telephone number and a mobile station identity need to be fixedly assigned to a mobile phone terminal in the current mobile communication system, it is concerned that telephone numbers may run out with increase in the number of subscribers or that mobile station identities may run out with increase in the number of MNP service users. 
     As a countermeasure against this problem, there is a proposal to increase the number of digits of a telephone number or a mobile station identity. However, with increase in the number of digits, there will be a need to reconstruct a communication infrastructure, make adaptations on a mobile phone terminal, and the like. Therefore, it is difficult to implement the proposal. 
     Meanwhile, Japanese Patent Application Publication No. 2002-261935 describes a telephone number distribution system as follows. In this system, a temporary telephone number is issued to a telephone terminal while the temporary telephone number is associated with a telephone number fixedly assigned to the telephone terminal. Then, a telephone call made by another telephone terminal using the temporary telephone number is transferred to the telephone terminal. However, this system is simply for hiding a true telephone number and preventing others from maliciously using the true telephone number. For this reason, this system is not capable of solving the above-described problem at all. 
     A communication terminal according to an aspect of the present invention includes: first means for transmitting to a network a communication start request having a first telephone number and a first terminal identity which are previously permitted to use; and second means for originating a call by using a second telephone number or a second terminal identity which has been received as a response to the communication start request and is necessary to continue communication. 
     Furthermore, a network server according another aspect of the present invention includes: first means for verifying a communication terminal based on a first terminal identity in response to a communication start request of the communication terminal, the request including a first telephone number and the first terminal identity which are previously permitted to use; and second means for informing the communication terminal of a second telephone number or a second terminal identity which is necessary for the communication terminal to continue communication, in accordance with the verification of the communication terminal. 
     Moreover, a communication network system according to another aspect of the present invention includes: a communication terminal for transmitting a communication start request having a first telephone number and a first terminal identity which are previously permitted to use; and a network server for verifying the communication terminal based on the first terminal identity in response to the communication start request and informing the communication terminal of a second telephone number or a second terminal identity which is necessary for the communication terminal to continue communication, in accordance with the verification of the communication terminal. 
     In other words, according to the present invention, a network server can dynamically assign a telephone number or a terminal identity to a communication terminal, thereby allowing the communication terminal to perform communication. 
     SUMMARY 
     According to the present invention, it is possible to, only when necessary, assign a telephone number and a terminal identity to a communication terminal where the frequency of communication is relatively low (for example, a terminal which downloads debugging software and acquires inventory control information), thereby effectively utilizing a telephone number and a terminal identity. 
     Furthermore, since there is no need at all to change a system itself of a telephone number and a terminal identity, there is also an advantage that renovation for the existing communication infrastructure and communication terminal is not necessary. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are block diagrams showing configuration examples of an embodiment of a communication network system according to the present invention. 
         FIG. 2  is a sequence diagram showing a first operation example of the embodiment of the communication network system according to the present invention. 
         FIG. 3  is a sequence diagram showing an example of the establishment of control connection and of security control operations in the embodiment of the communication network system according to the present invention. 
         FIG. 4  is a view showing a configuration example of a layer  3  processing signal used in the embodiment of the communication network system according to the present invention. 
         FIG. 5  is a sequence diagram showing a second operation example of the embodiment of the communication network system according to the present invention. 
         FIG. 6  is a view showing a system to assign a telephone number used in the current mobile communication system in Japan. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Descriptions will hereinafter be given of an embodiment of a communication network system according to the present invention with reference to  FIGS. 1A to 5 . 
     Configuration Example: FIG. 1 
     A communication network system according to the embodiment includes: a communication terminal  10  shown in  FIG. 1A ; and a network server  20  shown in  FIG. 1B . The communication terminal  10  includes: a transmitter/receiver  11  being a wireless interface with the network server  20 ; a SIM card  12  storing in advance a telephone number PN and a mobile station identity MSI; and a controller  13  which requests the network server to start communication via the transmitter/receiver  11 , and which continues communication using a telephone number or a mobile station identity informed by the network server  20  as a response to the request. 
     In addition, the controller  13  includes a layer  3  function defined in a general mobile communication scheme. In other words, as shown in  FIG. 1A , the controller  13  includes: a radio resource control (RRC) controlling radio resource such as a wireless carrier and a time slot; a mobility management (MM) managing location registration, cell switching, and the like; and a call control (CC) controlling call connection such as an incoming or outgoing call. Please note that, in the following descriptions, the radio resource control, the mobility management, and the call control in the controller  13  may be represented by codes RRC 10 , MM 10 , and CC 10 , respectively. 
     On the other hand, as shown in  FIG. 1B , the network server  20  includes: a base station  21  and a radio controller  22  which form a radio access network (RAN); and an exchange  23  and a service controller  24  which form a core network (CN). 
     Moreover, the base station  21 , the radio controller  22 , and the exchange  23  include radio resource controls RRC 21  to RRC 23 , respectively. The radio controller  22  and the exchange  23  include mobility managements MM 22  and MM 23 , and call controls CC 22  and CC 23 , respectively. Please note that, in the following descriptions, the radio resource controls RRC 21  to RRC 23 , the mobility managements MM 22  and MM 23 , and the call controls CC 22  and CC 23  may collectively be called codes RRC 20 , MM 20 , and CC 20 , respectively. 
     Operation Examples: FIGS. 2 to 5 
     Next, descriptions will sequentially be given of a first and a second operation example of the embodiment with reference to  FIGS. 2 to 5 . Here, the first operation example deals with a case where the network server  20  dynamically assigns a telephone number to the communication terminal  10 . Moreover, the second operation example deals with a case where the network server  20  dynamically assigns a mobile station identity to the communication terminal  10 . 
     Please note that each processing in the network server  20  described in the first and the second operation example may be performed singly by any one of the radio controller  22 , the exchange  23 , and the service controller  24 , which are shown in  FIG. 1B , or may be performed in cooperation. 
     First Operation Example (Dynamic Assignment of Telephone Number): FIGS. 2 to 4 
     As shown in  FIG. 2 , the communication terminal  10  (the controller  13 ) first originates a call using a temporary telephone number PN 1  and a mobile station identity MSI assigned fixedly thereto, and then requests the network server  20  to start communication (Step S 1 ). Here, it is sufficient if a value that the network server  20  can at least recognize the communication terminal  10  as a terminal which requests dynamic allocation of a telephone number is set for the temporary telephone number PN 1 . For example, it is possible to cause the communication terminal  10  to share the same telephone number with another communication terminal as the temporary telephone number. 
     Communication start processing is then performed by mutual operations of the communication terminal  10  and the network service  20 , and the communication terminal  10  is verified (Step S 2 ). Moreover, in the communication start processing, the establishment of control connection and security control (Step S 21 ), a call setup (Step S 22 ), and a radio access bearer setup and a line setup (Step S 23 ) are performed as illustrated in  FIG. 2 . 
     In other words, as shown in  FIG. 3 , the radio resource control RRC  10  in the communication terminal  10  transmits an RRC connection request (a signal) to the radio resource control RRC 20  in the network server  20  (Step T 1 ). The radio resource control RRC 20  transmits RRC connection start notification to the radio resource control RRC 10  (Step T 2 ). In response to this, the radio resource control RRC 10  transmits an RRC connection completion report to the radio resource control RRC 20  (Step T 3 ). These Steps T 1  to T 3  make it possible to establish control connection between the communication terminal  10  and the network server  20 , thereby transmitting and receiving control information. 
     Here, as shown in  FIG. 4 , a signal SG processed at a layer  3 , is approximately composed of an address field F 1 , a control field F 2 , and an information field F 3 . In the address field F 1 , the type of processing at the layer  3  and the mobile station identity MSI are stored, and an extended bit for absorbing the system dependency of an MSI bit length is provided. Furthermore, in the control field F 2 , a transmission sequence number and a receipt sequence number for making it possible to control the order of signals SG are stored, and in the information field F 3 , various types of information used at the layer  3  are stored. 
     The mobility management MM 10  in the communication terminal  10  which detected the establishment of control connection requests the mobility management MM 20  in the network server  20  to register the location (Step T 4 ). Additionally, in order to ensure the security of the control connection, verification between the mobility managements MM 10  and MM 20  is performed (Steps T 5  and T 6 ), and security control between the radio resource control RRC 10  and RRC 20  is performed (Steps T 7  and T 8 ). 
     Moreover, the network server  20  recognizes that the communication terminal  10  is a valid terminal (a contract terminal) when receiving a security response from the communication terminal  10  in the above Step T 8 . 
     Afterwards, the mobility management MM 20  transmits a location registration response to the mobility management MM 10 . However, at this point, the mobility management MM 20  uses a temporary MSI (TMSI) instead of the mobile station identity MSI as illustrated in  FIG. 3  (Step T 9 ). The TMSI is for being temporarily assigned for the purpose of improving the efficiency of subsequent communication (reducing the amount of information (bit length)) while being associated with the mobile station identity MSI. The mobility management MM 10  transmits a TMSI assignment response to the mobility management MM 20  (Step T 10 ) Returning to  FIG. 2 , a call setup between the communication terminal  10  and the network server  20  (Step S 22 ), a radio access bearer setup in radio sections, and a line setup based on a connection destination number (unillustrated) and the like (Step S 23 ) are performed by mutual operations of the communication terminal  10  and the network server  20 . Consequently, communication between the communication terminal  10  and the network sever  20  becomes possible. 
     The communication terminal  10  then checks whether or not the temporary telephone number PN 1  has been changed (that is, whether or not a new telephone number has been assigned by the network server  20 ) (Step S 3 ). At this point, the temporary telephone number PN 1  has not been changed. Therefore, the communication terminal  10  performs the processing of assigning a telephone number shown in Step S 5 . Furthermore, the network server  20  checks whether or not a telephone number that the communication terminal  10  used to originate a call is the temporary telephone number PN 1  (Step S 4 ), and again, the processing goes to Step S 5  to perform the processing of assigning a telephone number. 
     Specifically, the communication terminal  10  first transmits information UI unique to its own terminal (for example, a manufacturer, a model name, and a manufacturing number) to the network server  20  (Step S 51 ). The network server  20  verifies the terminal unique information UI using information previously acquired from a manufacturer of the communication terminal  10  and the like (Step S 52 ). 
     If the verification result is “OK” (Step S 53 ), the network server  20  secures a telephone number PN 2  for causing the communication terminal  10  to continue communication (Step S 54 ), and informs the communication terminal  10  of the telephone number PN 2  (Step S 55 ). Here, the telephone number PN 2  is one of the finite number of telephone numbers prepared in advance at the network server  20  (a number smaller than the number of communication terminals using the network server  20 ) Please note that the network server  20  informs the communication terminal  10  of guidance such as originating a call again later when failing to secure a telephone number. 
     Then, the communication terminal  10  and the network server  20  complete the communication once after performing the specified processing of ending communication (Step S 56 ). Please note that if the verification result is “NG” in the above Step S 53 , securing and informing a telephone number are not performed in the above Steps S 54  and S 55 , respectively. 
     After the communication terminal  10  saves the original telephone number PN 1  in memory (unillustrated) and the like, a call is originated again by using the telephone number PN 2  informed in the above Step S 55  and the mobile station identity MSI (Step S 6 ). Accordingly, the communication terminal  10  is verified in the above Step S 2 . In this case, since the telephone number has been changed from PN 1  to PN 2  (in other words, since the network server  20  already assigned to the communication terminal  10  the telephone number PN 2  instead of the temporary telephone number PN 1 , and the communication terminal  10  originated a call by using the assigned telephone number PN 2 ), the communication terminal  10  and the network server  20  continue communication without performing the processing of assigning a telephone number as shown in the above Step S 5  (shift during communication) (Step S 71 ). 
     When the communication ends, the communication terminal  10  discards the telephone number PN 2  (writes a telephone number used for originating a call back to PN 1  saved) (Step S 72 ). 
     In addition, the network sever  20  records a communication charge to a billed party corresponding to the terminal unique information UI previously designated by a manufacturer of the communication terminal  10  and the like (Step S 73 ). Consequently, it is possible to securely bill a communication charge even if a telephone number is dynamically assigned to the communication terminal  10 . 
     In addition, the network server  20  releases the telephone number PN 2  secured in the above Step S 54  (makes reassignment to another communication terminal possible) (Step S 74 ). Consequently, it is possible to effectively use the finite number of telephone numbers. 
     Second Operation Example (Dynamic Assignment of Mobile Station Identity): FIG. 5 
     As shown in  FIG. 5 , the communication terminal  10  first originates a call by using the telephone number PN assigned fixedly thereto and a temporary mobile station identity MSI 1 , and requests the network server  20  to start communication (Step S 8 ). Here, it is sufficient if a value is set for the temporary mobile station identity MSI 1  so that the network server  20  can recognize the communication terminal  10  as a terminal which requests dynamic allocation of a mobile station identity and can normally perform communication start processing similar to Step S 2  (please refer to  FIG. 2 ) shown in the above first operation example. For example, it is possible to cause the communication terminal  10  to share the same mobile station identity with another communication terminal as the temporary mobile station identity MSI 1 . 
     The communication terminal  10  and the network server  20  then check whether or not the temporary mobile station identity MSI 1  has been changed, respectively, unlike the above Steps S 3  and S 4  (Steps S 9  and S 10 ), as well as going to Step S 11  to perform the processing of assigning a mobile station identity. Please note that although not illustrated, the network server  20  checks (determines) whether or not a telephone number used to originate a call is the telephone number PN in parallel with the above Step S 10 . 
     In other words, similarly to the above Steps S 51  and S 52 , the communication terminal  10  transmits the terminal unique information UI to the network server  20 , and the network server  20  verifies the information. 
     If the verification result is “OK”, the network server  20  secures a mobile station identity MSI 2  and informs the communication terminal  10  of the mobile station identity MSI 2 , unlike the above Steps S 54  and S 55  (Steps S 111  and S 112 ). Here, the mobile station identity MSI 2  is one of the finite number of mobile station identities prepared in advance at the network server  20 , similarly to the telephone number shown in the above first operation example. 
     Then, the communication terminal  10  and the network server  20  complete the communication once, similarly to the above Step S 56 . The communication terminal  10  originates a call again using the telephone number PN and the mobile station identity MSI 2  (Step S 12 ). Consequently, both of the communication terminal  10  and the network server  20  shift during communication, similarly to the above Step S 71 . 
     When the communication ends, the communication terminal  10  discards the mobile station identity MSI 2  (Step S 131 ). In addition, the network server  20  releases the mobile station identity MSI 2  after recording a communication charge similarly to the above Step S 73  (Step S 132 ). Consequently, even if a mobile station identity is dynamically assigned to the communication terminal  10 , it is possible to securely bill a communication charge and effectively use the finite number of mobile station identities. 
     Although the inventions has been described above in connection with several preferred embodiments thereof, it will be appreciated by those skilled in the art that those embodiments are provided solely for illustrating the invention, and should not be relied upon to construe the appended claims in a limiting sense. 
     For example, it is also possible to provide the present invention as a program for causing a computer to execute each processing of a communication terminal and a network server as shown in the above embodiment.