Abstract:
A method of managing mobile station operational parameters is disclosed in which a mutual authentication between a mobile station and a network is performed. The present method allows a mutual authentication while maintaining the updating procedure of the mobile station operational parameters in the conventional procedure.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. P99-6891, filed on Mar. 3, 1999, which is hereby incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     This invention relates to a mobile communication system and more particularly to a method of managing mobile station operational parameters in the mobile communication system. In the present invention, the mobile station operational parameters are managed such that a mutual authentication between a mobile station and a network can be performed while maintaining the same number of operational parameter updating. 
     BACKGROUND OF THE INVENTION 
     Mobile communication networks based on cellular or personal communication system (PCS) have been expanding due to the rapid development in the information and communication field. Accordingly, various functions of the mobile communication networks have been continuously upgraded to provide a more convenient communication service to subscribers. 
     To upgrade specific functions on the network, a network manager must change both programs and operational parameters installed in communication apparatus such as a base station (BS), a base station controller (BSC), a mobile switching center (MSC), a home/visitor location register (HLR/VLR), and authentication center. Moreover, the network manager must also change specific parameters in each mobile stations. However, to change specific parameters in a mobile station, the mobile station must be either physically connected to a system enabled to change such parameters or a user must manually and appropriately operate the keypad of the mobile station. 
     Therefore, a technology which allows changing of specific parameters of the mobile station by wireless communication has been developed, known as the Over-The-Air Parameter Administration (OTAPA). The OTAPA is disclosed in IS-725-A, pp. 1-19 and 3-75 to 3-78, Apr. 13, 1999 or the PCT application No WO 98/41044 by Northern Telecom Inc., fully incorporated herein. 
     According to the IS-725-A, an authentication procedure for a communication network is included in the OTAPA process such that a mobile station may confirm whether the network is correct, but an authentication procedure for a mobile station is not included. As a result, a person may illegally change the specific parameters of a mobile station and receive illegal communication service, thereby affecting the overall service to the authorized users, i.e. mobile stations, of a network. Therefore, the reliability of the management system for authorized users of a network may be dropped, and the quality of service may also decline. 
     Although the network may first perform an authentication procedure of a mobile stations before the OTAPA process, if the authentication procedure of the mobile station is performed independently, the entire OTAPA process will be elongated. Moreover, a separate authentication procedure must be added, thereby increasing the load in a communication network. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to solve at least the problems and disadvantages of the related art. 
     An object of the present invention is to allow a management which can perform a mutual authentication between a mobile station and a network. 
     A further object of the present invention is to allow a management which can perform a mutual authentication between a mobile station and a network while maintaining the same number of mobile station operational parameter updating procedure as in the conventional procedure. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 
     To achieve the objects and in accordance with the purposes of the invention, as embodied and broadly described herein, a method of managing mobile station operational parameters in a wireless communication network comprises the notifying a mobile station that an update of the mobile station operational parameters has been initiated upon an update request from the mobile station; performing a mutual authentication procedure between the mobile station and a network; transmitting from the network, at least one mobile station operational parameter to the mobile station; and receiving and updating the corresponding mobile station operational parameters at the mobile station. 
     The mutual authentication may further comprise generating and transmitting from the network, a first random number to the mobile station, and generating a first authentication utilizing the first random number; generating at the mobile station, a second authentication utilizing the first random number and a second random number, and transmitting to the network the second random number with the second authentication, and then generating a third authentication utilizing the second random number; comparing at the network, the second authentication with the first authentication and authenticating the mobile station; generating at the network, a fourth authentication unitizing the second random number when the first authentication and the second authentication are equivalent, and transmitting the fourth authentication to the mobile station; comparing at the mobile station, the third authentication with the fourth authentication and authenticating the network in accordance with the results of the comparison. 
     Also, the mutual authentication may further comprise generating and transmitting, at the mobile station, a third random number to the mobile station, and generating a fifth authentication utilizing the third random number; generating, at the network, a sixth authentication utilizing the third random number and a fourth random number, and transmitting the fourth random number with the sixth authentication to the mobile station, and then generating a seventh authentication utilizing the fourth random number; comparing, at the mobile station, the fifth authentication with the sixth authentication and authenticating, at the mobile station, the network in accordance with the comparison result; generating, at the mobile station, an eighth authentication unitizing the fourth random number when the fifth authentication and the sixth authentication are equivalent, and transmitting the eighth authentication to the network; comparing, at the network, the seventh authentication with the eighth authentication and authenticating the mobile station in accordance with the comparison results. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
     FIGS. 1 and 2 are time sequence diagrams explaining a mutual authentication procedure between a mobile station and a network according to a first embodiment of the present invention; 
     FIG. 3 is a time sequence diagram explaining the detailed OTAFA process according to a first embodiment of the present invention; and 
     FIGS. 4 and 5 are time sequence diagrams explaining a mutual authentication procedure between a mobile station and a network according to a second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     To perform OTAPA, various functions are implemented in each mobile station and each element of a wireless communication network. 
     Both a mobile station and a network must have a capacity,to internally generate a random number when necessary, and must store a secret key (A_KEY) as well as a shared secret data (SSD). The A_KEY is a 64 bit pattern stored in a mobile station and in either a home location register (HLR) or an authentication center (AC). It is used to generate or update the mobile station&#39;s SSD. The SSD is a 128 bit pattern stored in the mobile station and is known by a base station. Also, the HLR must know that each mobile station supports the OTAPA function. 
     The OTAPA procedure can generally be divided into four parts. First, the network notifies a mobile station the start of a mobile station operational parameter update in response to a user&#39;s request through the mobile station by a manual operation of the pad on the mobile station, a user&#39;s request through the network, or in response to the network during specific states of either the mobile stations of the network. In the present invention, the network encompasses the elements between a mobile switching center and an authentication center (AC). 
     Second, the mutual authentication procedure between the mobile station and the network is performed. In the authentication procedure, the network may first authenticate the mobile station and then the mobile station may authenticate the network; or the mobile station may first authenticate the network and then the network may authenticate the mobile station. 
     FIGS. 1 and 2 explain a first embodiment of the mutual authentication procedure in which the network authenticates the mobile station prior to the mobile station authentication of the network. 
     Referring to FIGS. 1 and 2, the network generates a first random number RAND and requests a unique challenge order from a mobile station MS using OTAPA Request message as shown in a 2  of FIG. 2. A message notifying the initiation of the mobile station operational parameters update may be included in the OTAPA message. Also, the network generates a first authentication AUTHRs utilizing the first RAND. 
     The mobile station MS receives the first RAND from the network and generates a second authentication AUTHRm utilizing the first RAND. The mobile station further generates and transmits to the network a second random number RANDBS with the second AUTHRm. Thus, the mobile station MS generates a unique challenge response and requests a base station challenge order to a HLR or AC through a base station BS or MSC/OTAPA of the network utilizing the OTAPA response as shown in b 2  and c 2  of FIG.  2 . Thereafter, the mobile station MS generates a third authentication AUTHBSm utilizing the second RANDBS. 
     In the above case, the third authentication AUTHBSm is generated after transmitting the second random number RANDBS and the second authentication AUTHRm. However, the mobile station may generate the third authentication AUTHBSm prior to the transmission of the second random number RANDBS and the second authentication AUTHRm. 
     After receiving the transmission from the mobile station MS, the HLR/AC of the network compares the second AUTHRm with the first AUTHRs generated in the network. If the first AUTHRs and the second AUTHRm are equivalent, the network generates a fourth authentication AUTHBSs utilizing the second RANDBS and transmits the fourth authentication AUTHBSs to the mobile station MS through a validation request as shown in e 2  of FIG.  2 . Here, the network may first generate the fourth authentication AUTHBSs and then transmit the fourth AUTHBSs depending upon the comparison. 
     The mobile station MS receives the fourth AUTHBSs from the network and compares the third AUTHBSm with the fourth AUTHBSs. If the two authentications AUTHBSm and AUTHBSs are equivalent, the mobile station MS forwards to the network a message indicating that a mutual authentication was successfully performed through a validation response as shown in f 2  of FIG.  2 . 
     In the above described mutual authentication procedure, the mobile station may generate the first authentication. In such case, the network would generate and store the first random number RND, and transmit the first random number RAND to the mobile station MS. When the first random number RAND is received, the mobile station MS would generate the first authentication utilizing the first random number RAND transmitted by the network, and generate and transmits the second random number RANDBS with the first authentication to the network. The mobile station MS would next generate the second authentication utilizing the second random number RANDBS. 
     Thus, the network would generate the third authentication utilizing the first RAND and compare the first authentication with the third authentication to authenticate the mobile station MS. If the first and third authentications are equivalent, the network would generate the fourth authentication utilizing the second random number RANDBS and transmit the fourth authentication to the mobile station MS. 
     In the above cases, the mobile station may generate the second authentication prior to the transmission of the second random number RANDBS and the first authentication. Also, the network may first generate the fourth authentication and then transmit the fourth authentication depending upon the result of the comparison. 
     Therefore, the mobile station MS would authenticate the network by comparing the fourth and the second authentications, and if the mutual authentication is successfully performed, the network transmits the necessary parameter value(s) to the mobile station MS. Finally, the mobile station MS receives the parameter values and updates the old parameters). 
     FIG. 3 is a sample time sequence diagram explaining the OTAFA process according to an embodiment in which the mobile station generates the first authentication. Referring to FIG. 3, when operational parameters of a mobile station MS  10  requires a change due to a user&#39;s request through the MS  10  or the network, or due to specific states of either the MS  10  or the network, an Over-the-Air Service Provisioning Function (OTAF)  40  of the network queries the HLR  50  to determine the MS′  10  availability for the OTAPA, as shown in a 3  and b 3  of FIG.  3 . 
     The SMSRequest (SMSREQ) is utilized either in an operation requesting a Short Message Service (SMS) of the mobile station MS  10  or in the OTAPA procedure requesting a location information for the OTAPA functions in accordance with the present invention. The Service Indicator (SRVIND) is utilized to determine the service options as OTA Service Provisioning (OTASP) or OTAPA. Also, the smsreq is the response message for the SMSREQ. Generally, messages indicating an initiation of an operation is denoted by capital letters, while messages indicating a response to the operation is expressed in small letters. 
     If the MS  10  is OTAPA capable, the OTAF  40  generates and stores a random number RAND to be used in the authentication process. The OTAF  40  also notifies the start of the OTAPA procedure to the MS  10  through a message shown in c 3 . Particularly, the OTAF  40  transmits the random number RAND with the message SMSDelivery Point To Point (SMDPP). 
     The SMDPP is utilized in the transmission of the short message in SMS and in the transmission of messages between the MS  10  and the OTAF  40  as defined in IS-683-A. The ActionCode (ACTCODE) is a parameter utilized in the determination of the contents for update and the SMS_BearerData is a parameter for transmitting messages between the MS  10  and the OTAF  40 . 
     Subsequently, the MS  10  receives the random number RAND from the OTAF  40  and generates a XCREDSSD by a XOR operation using the shared secret data SSD and the secret key A_KEY. The MS  10  generates an authentication AUTHR utilizing the XOREDSSD, and also utilizing a Mobile Identification Number (MIN) and an Electric Serial Number (ESN), already stored therein. The MS  10  then generates a new random number RAND_OTAPA to be used for authenticating the network and generates a new authentication AUTH_OTAPA utilizing the RAND_OTAPA, the XOREDSSD, the MIN and the ESN. 
     Particularly, the AUTHR is obtained by performing an authentication algorithm utilizing the secret key A_KEY, the random number RAND and the MIN stored in the MS  10 . If the network were to generate the first authentication, the first authentication would be obtained by performing an authentication algorithm utilizing the secret key A_KEY, the random number RAND and the MIN stored in the AC  60 . Here, the MIN is a 40 bit number and is a digital representation of the 10 digit number assigned to a mobile station. The ESN is a 32 bit number assigned by the mobile station manufacturer to uniquely identify the mobile station equipment. 
     Thus, the MS  10  transmits to the OTAF  40  a response message with the random number RAND_OTAPA and the authentication AUTHR generated using the random number RAND from the OTAF  40 , shown in e 3  of FIG.  3 . Here, the Smdpp is a response message of the SMDPP message, the RAND_OTAPA (Random OTAPA) is a random number, and a NAM Lock Indicator (NAM_LOCK_IND) is a parameter indicating whether an update of parameter(s) is protected. 
     Subsequently, the OTAF  40  receives the OTAPA response message transmitted from the MS  10 . If the OTAF  40  determines that the NAM is protected, the OTAF  40  initiates the authentication procedure by converting the received random number RAND_OTAPA into a random number RANDBS. The OTAF  40  then transmits to the AC  60  the random number RANDBS, the authentication AUTHR and the random number RAND as shown in f 3  and g 3 . The OTASPREQ is a parameter utilized by the OTAF  40  to initiate the authentication procedure. 
     After receiving the random numbers RAND and RANDBS with the authentication AUTHR, the AC  60  again generates the authentication AUTHR using the random number RAND, XOREDSSD, MIN, and ESN by the same algorithm as described with reference to the MS  10 . Accordingly, the AC  60  compares the internally generated authentication AUTHR with the authentication AUTHR received from the MS  10 . If the two authentications are equivalent, the AC  60  generates and transmits to the OTAF  40  the fourth authentication AUTHBS with the generated XOREDSSD, MIN, ESN as shown in h 3  and i 3 . Here, the Authentication Response Base Station Challenge (AUTHBS) is equivalent to the authentication AUTHR, but denotes an authentication value obtained during a BASE Station Challenge. 
     The authentication AUTHBS utilized in the network is then converted into the authentication AUTH_OTAPA, a format for transmission or reception between the MS  10  and the OAF  40 . Thus, the OTAF  40  receives the authentication AUTHBS from the AC  60  in a message shown in h 3  and j 3 , and converts the authentication AUTHBS into the authentication AUTH_OTAPA. The converted authentication AUTH_OTAPA is transmitted to the MS  10 . 
     Receiving the authentication AUTH_OTAPA from the OTAF  40 , the MS  10  compares the received authentication AUTH_OTAPA with the internally generated authentication AUTH_OTAPA. If the two authentications AUTH_OTAPA are equivalent, the MS  10  recognizes that the mutual authentication between the MS  10  and the network is successfully performed. Accordingly, the MS  10  transmits to the OTAF  40  a message allowing the parameter update procedure as shown in  13 . 
     Thereafter, the OTAF  40  transmits to the MS  10  the necessary parameters as shown in m 3  to o 3 , and if appropriate also transmits an instruction message to store the parameters, shown in q 3 . Upon receiving the storage instructions from the OTAF  40 , the MS  10  updates or changes the old parameters with the newly received parameters and transmits to the OTAF  40  a message indicating a successful parameter update, shown in r 3  and s 3 . Finally, the OTAF  40  transmits to the MS  10  a message indicating a completion of the entire authentication procedure, shown in t 3  to v 3 . 
     FIGS. 4 and 5 illustrate time sequence diagrams explaining a mutual authentication procedure between a mobile station and a network according to a second embodiment of the present invention. 
     Referring to FIGS. 4 and 5, the network transmits to a mobile station MS a message notifying the initiation of OTAPA as shown in a 5  of FIG.  5 . The message notifying the OTAPA initiation may be included in the OTAPA message. Receiving the message, the mobile station MS generates a first random number RANDBS and generates a first authentication AUTHBSm utilizing the random number RANDBS. The mobile station MS also transmits to the network the random number RANDBS through OTAPA response as shown in b 5  and c 5  of FIG. 5 
     The network receives the random number RANDBS and generates a second authentication AUTHBSs using the random number RANDBS. The network further generates a random number RAND to be used in the authentication of the mobile station MS, and generates a third authentication AUTHRs utilizing the random number RAND. The network then transmits to the mobile station MS the generated authentication AUTHBSs with the random number RAND as shown in d 5  and e 5  of FIG.  5 . As in the first embodiment of the present invention, the third authentication AUTHRs may be generated either before or after transmitting the second authentication AUTHBSs and the random number RAND. 
     Upon receiving the authentication AUTHBSs and the random number RAND, the mobile station MS compares the authentication AUTHBSs with the internally generated authentication AUTHBSm in order to authenticate the network. If the two authentications AUTHBs and AUTHBSm are equivalent, the mobile station MS generates a fourth authentication AUTHRm using the random number RAND from the network. Thus, the mobile station MS transmits to the network the generated authentication AUTHRm through the Unique Challenge Response message as shown in f 5  of FIG.  5 . Here also, the mobile station MS may first generate the fourth authentication AUTHRm and then transmit the fourth authentication AUTHRm depending upon the results of the comparison. 
     Thus, the network receives the authentication AUTHRm from the mobile station MS through the Unique Challenge Response and compares the authentication AUTHRm with the internally generated authentication AUTHRs. If the two authentication AUTHRs and AUTHRm are equivalent, the authentication of the mobile station MS is successfully performed. Accordingly, the mutual authentication in which the mobile station MS authenticates the network prior to the network authentication of the mobile station MS is completed. 
     In the second embodiment of the mutual authentication procedure, the network may also generate the first authentication. In such case, the mobile station MS would generate and store the first random number RANDBS, and transmit the first random number RANDBS to the network. When the first random number RANDBS is received, the network would generate the first authentication utilizing the first random number RANDBS transmitted by the mobile station MS, and generate and transmits the second random number RAND with the first authentication to the mobile station MS. The network would next generate the second authentication utilizing the second random number RAND. 
     Thus, the mobile station MS would generate the third authentication utilizing the first RANDBS and compare the first authentication with the third authentication to authenticate the network. If the first and third authentications are equivalent, the mobile station MS would generate the fourth authentication utilizing the second random number RAND and transmit the fourth authentication to the network. 
     In the above cases, the network may generate the second authentication prior to the transmission of the second random number RAND and the first authentication. Also, the mobile station MS may first generate the fourth authentication and then transmit the fourth authentication depending upon the result of the comparison. 
     Therefore, the network would authenticate the mobile station MS by comparing the fourth and the second authentications, and if the mutual authentication is successfully performed, the network transmits the necessary parameter value(s) to the mobile station MS. Finally, the mobile station MS receives the parameter values and updates the old parameter(s). Moreover, the OTAFA procedure is carried out an analogous manner as described with respect to the first embodiment of the present invention. 
     In sum, a mutual authentication between a mobile station MS and a network according to the present invention can be performed within the OTAFA procedure in the related art. Thus, the present invention makes it difficult to change the mobile station operational parameter abnormally or illegally by unauthorized mobile station users. As a result, the present invention allows companies of the wireless communication network to increase legal subscription availability of mobile stations, thereby increasing the quality of service and reliability to manage networks. 
     The foregoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.