MXPA97008856A - Method and system for the termination of called enjoyment in mobility applications detelecomunicacio - Google Patents

Abstract

The present invention relates to a method for directing calls from a public switched telephone network to a mobile station within a mobile telephone network including the mobile telephone network a plurality of mobile telephone stations, a plurality of base stations to communicate with the mobile telephone stations, a plurality of mobile service switching centers for directing calls between the base stations and between the base stations and the public switched telephone network, a plurality of visitor location records for storing data in relation to the telephone stations mobile phones, and at least one local location register for storing all handling data in relation to all mobile telephone stations in the mobile telephone network, the method comprising the steps of: receiving a call directed to a mobile telephone station from of u a public switching telephone network in a mobile services switching center, attempting to locate a profile of the mobile telephone station in a visitor location record, the profile having an HLR demand indicator to indicate whether the local location registration should be requested verify a state of the HLR demand indicator, if the profile of the mobile telephone station is located in the visitor location record, send a demand message to a local location record requesting addressing information for the call, if the HLR demand indicator is set affirmative, complete the call to the mobile telephone station using the profile in the visitor location record, if the HLR demand indicator is set negative, send a demand message to the local location record requesting address information for the call, if the mobile phone profile is not in the visitor location record, and complete the call to the mobile telephone station using the routing information received from the local location record, if a demand message has been sent requesting address information to the loc location record

Description

METHOD AND SYSTEM. FOR TERMINATION OF IMPROVED CALL IN TELECOMMUNICATIONS MOBILITY APPLICATIONS Background of the Invention 1. Field of the Invention The invention disclosed is broadly related to telecommunications systems and more particularly relates to mobility applications. 2. Background Information In 1982, the global system for mobile communications (GSM) was established in Europe to provide a cellular mobile radio system. The basic function of GSM is to provide a mobile service of total vagabonding. The GSM protocol has been selected to be used around the world for digital cellular telephone service. The operating principles of the existing GSM digital cellular telephone system are described in the following references: Balston, DM, "Pan-European Cellular Radio," ("Pan-European Cellular Radio") IEEE Electrical and Communications Journal, No. 1, pp. 7-13, 1989. Gooidman, D.J., "Second Generation Wireless Information Networks" ("Second Generation Wireless Information Networks"), IEEE Transactions on Vehicular Technology, VT-40, May 1991, p. 366-374. Pautet, M.B., and Monly, M., "GSM Protocol Architecture: Radio Subsystem Signaling" ("GSM Protocol Architecture: Radio Subsystem Signaling"), IEEE Vehicular Technology Conference, May 1991, p. 326-332. A cellular mobile radio system includes a variety of elements. There are mobile stations (cell phones). Each cell of the cellular network contains a base station that transmits calls to and receives calls from mobile stations using a radio. There are base station controllers (BSC) which control a group of base stations. There are mobile switching centers (MSCs) which direct calls between the base stations, other mobile switching centers and the public switched telephone network. Each MSC is associated with a local location record (HLR) and a visitor location record (VLR). The HLR stores a mobile station profile for each mobile station in the network. When operating a mobile station, the profile of the mobile station in the HLR corresponding to that mobile station is sent over a data network to a VLR associated with the MSC serving the cell in which the mobile station is located. Several data network messages are required to complete each transaction. A transaction occurs each time a call is placed or received by a mobile station, as well as each time a mobile station is switched on. A problem of the prior art is that the call traffic capacity of the system is limited by the data handling capability of the data network that couples the VLRs with the local location register. The message handling capacity of the data network can be increased by increasing the number of HLRs or by increasing the overall performance of the data network, but this requires investment in new or additional equipment. SUMMARY OF THE INVENTION An object of the invention is a method for reducing the traffic of network messages between a local location register (HLR) and other portions of a mobile network of global systems (GSM). These and other objects, features and advantages are carried out by the invention disclosed herein. The invention provides for the selective elimination of the need to access the HLR for those calls made to a mobile station having its own local location in the same base station as that which receives the call coming from the public switched telephone network. According to the invention, the visitor location register (VLR) includes a mobile station profile for each local mobile station in the vicinity of the base station. A HLR demand indicator is included with the mobile station profile that determines if access from this base station to the HLR is required, for example to advance the call or for vagrancy informat If the HLR demand indicator indicates that access to the HLR is not needed, then sufficient informatis available in the mobile statprofile to provide appropriate addressing informatto the local mobile switching center (MSC) at the local base stat to complete the call to the mobile stat If the mobile statis located anywhere in the GSM network and is not located close to the base statreceiving the call from the public switching telephone network, or alternatively, if it is desired to have a call advance feature, then the subscriber profile stored in the VLR at the base statwill have its HLR demand indicator set. When the HLR demand indicator is established, the incoming call from the public switching telephone network will initiate a response through the MSC and the VLR, to cause the base statto access the HLR in order to obtain the addressing informatnecessary to complete the call. The HLR demand indicator in the VLR serves as a flag or actuator to initiate access by the HLR base stat In this way, the large number of calls from a public switched telephone network directed to a mobile statwithin the geographical vicinity of the base statreceiving the incoming call can be handled without exchanging control informatwith the centralized HLR. DESCRIPTOF THE FIGURES The objects, features and advantages will be appreciated more fully in relatto the accompanying figures. Figure 1 is an architectural diagram of a GSM network, according to the invent Figure 2 is an organizatl diagram showing the local locatrecord and the visitor locatrecords, according to the invent Figure 3 is a flowchart of a sequence of operatl steps for the MSC 300 call processing program, according to the invent Figure 4 is a functl block diagram of the mobile switching center 104, and its MSC 400 processor, according to the invent Figure 5 illustrates a data flow diagram of the GSM network in the prior art.

Figure 6 is a data flow diagram illustrating the GSM network, according to the invention. Figure 7 is a data flow diagram of the GSM network, according to the invention. Figure 8 is a data flow diagram of the GSM network in the prior art. Figure 9 is a data flow diagram of the GSM network according to the invention. Figure 10 is a sequence diagram of a basic call with a subscriber present, according to the invention. Figure 11 is a sequence diagram of a basic call with a subscriber not present, according to the invention. Figure 12 is a sequence diagram of the go-HLR parameter in the ISD mode for the basic, subscriber call present, according to the invention. Figure 13 is a sequence diagram of a basic call, without a subscriber present, for the alternate modality of the invention referred to in Figure 12. DETAILED DESCRIPTION OF THE INVENTION In Figure 1, many of the elements shown represent a plurality of elements similar, although only a limited number are shown and described. The public switching telephone network 102 is connected to the mobile services switching center (MSC) 104. The base station controller (BSC) 106 is connected to the MSC 104, and the base transceiver station (BTS) 108 is connected to the BSC 106. Each BTS 108 illustrated in Figure 1 represents a plurality of BTSs 108 that are part of a group of base stations controlled by the BSC 106. The BTS 108 transmits and receives radio signals on the antenna 114. For most of the the network, the BTSs are organized in a repetition pattern of seven cells or twelve cells with an omnidirectional coverage for each one. In this way, the seven or twelve BTSs are connected to each BSC 106. Most BTSs have between 20 and 30 voice channels with a signaling channel carrying out all the functions of paging and access per cell. Each BSC 106 represents a plurality of BSCs connected to the MSC 104. The BSC 106 controls the operation of each connected BSC 108. Each MSC 104 represents a plurality of MSCs. The MSC 104 is a digital exchange with a distributed control architecture specially adapted for operation in the cellular environment. The base transceiver stations 108 and the base station controllers 106 are connected to the MSCs 104 on digital lines. The MSCs in a local area are connected to form a local network 100. Each local network 100 has an access MSC 105 that provides communication with other local networks 100 'over the communication line 109 and with the local location register. (HLR 110, on communication line 111. The system also includes mobile stations 120 representing a plurality of mobile stations present in the network. The mobile station 120 includes the mobile station component 122 and its antenna 124, which receives and transmits radio signals with the antenna 114 of the base station 100. The mobile station 120 also includes the subscriber identity module (SIM) 126 which personalizes a mobile station 120. Each visitor location register (VLR) 112 is associated with an MSC 104. Each MSC 104 typically has its own VLR 112, but this is not required. The access MSC 105 provides access services between a VLR 112 and the MSC 104, when the VLR 112 is located separately from the MSC 104, as shown in Figure 1. The VLR 112 stores the selected data in relation to the stations mobile 120 which are visitors within the local network 100 associated with the VLR 112 and its MSC 104. The data stored in the VLR 112 is transferred from the HLR 110 to the VLR 112 for each mobile station 120 within the local network 100 of the VLR 112 These data may include the international mobile station (IMSI) identity, the international mobile station ISDN number and other information that includes the current geographical location of the mobile station 120 and the services available for the mobile station 120., for example, voice services or complementary data services. Each MSC 104 is associated with a local location register (HLR) 110 in the network. In principle, only one local location register 110 needs to exist for the entire GSM network. In practice, there are generally several in order to accommodate the large amount of data that is required to be stored in the HLR 110. The local location register (HLR) 110 stores all the handling data in relation to all the mobile stations 120 in the net. These data include the international mobile station (IMSI) identity, the mobile station profile of the unique capabilities and services for the mobile station 120, and the location of the mobile station 120 within the total GSM network. The HLR 110 is connected over the signaling network 113 to the MSCs 104 within each network 100 via the access MSC 105. The control messages are exchanged between the MSC 104, the VLR 112 and the HLR 110, using the protocol of communication by mobile application (MAP). Each mobile station 120 is assigned to a specific HLR 110 and the code forming a part of the station identity (IMSI) for a particular mobile station 120 will include the information identifying the specific HLR 110. This information is used to allow make calls when, for example, a mobile station 120 visits a different network to its local network. The mobile station 120 is requested to pass the IMSI over the uplink to the nearest base station 100 and this value is advanced through the MSC 104 to the VLR 112 connected to the MSC 104. In the GSM systems of the prior art , the VLR 112 then accesses the HLR 110 through fixed network links, in order to obtain the selected information necessary for the registration of the mobile station 120. A mobile station roaming number (MSRN) and a mobile subscriber identity Temporary (TMSI) are also assigned by the visited network. An authentication process is carried out and if this is successful access is allowed and the calls originated by the mobile station can be made then, while the registration of the location of the mobile station allows incoming calls coming from the telephone network of public switching 102, are directed to the correct base station 100 and sent over the radio link to the mobile station 120. A call can be placed from the public switching telephone network 102 through the mobile services switching center 104, directed to the mobile station 120. If the geographic location of the mobile station 120 is closer to one of the base transceiver stations 108 'or 108A' connected in the remote network 100 ', which is controlled by the service switching center mobile (MSC) 104 ', then the call is routed from the local network 100 and its mobile services switching center 104, to the network remote 100 'and the mobile services switching center 104'. Then, in the remote network 100 ', the MSC 104' directs the call to any base transceiver station 108 'or 108A' depending on which one is closest to the mobile station 120. If a call is placed to a mobile station 120 which is located within the service area of one of the base transceiver stations 108 or 108a directly connected to the mobile services switching center 104, then the call is switched from mobile service switching (MSC) 104 directly to the base transceiver station 108 or 108A which is in the closest proximity to the mobile station 120. In the prior art the VLR 112 always accesses the HLR 110 over the fixed network link 113, in order to obtain the selected information necessary for the registration of the mobile station 120 and the local network 100. The reference by the VLR 112 to the local location register 110 occurs each time a call is placed between the telephone network of public office 112 and mobile station 120, in the prior art. It can be seen that the signaling activity between the HLR and the VLR is significantly high and can form a bottleneck that limits the number of cellular calls that can be placed in the GSM network of the prior art. In Figure 2 it can be seen how the present invention performs the reduced data flow. Figure 2 shows the HLR 110, the VLR 112 and the VLR 112 'in more detail. The HLR 110 includes a plurality of profiles 202 for a plurality of mobile stations 120. For example, a profile 202 of the mobile station 120A is the profile corresponding to the mobile station 120A of Figure 2. A demand indicator of HLR is included. 204 F (A) together with a profile for each mobile station 120. The demand indicator of HLR 204 is a binary value which when set to zero indicates that there is no need for a VLR 112 to make a reference on line 113 to HLR 110. When the demand indicator of HLR 204 F (A) is set equal to a binary value of one, the indicator indicates that it is necessary for VLR 112 to make a reference on line 113 to HLR 110. The indicator HLR demand is established as long as a service is activated in the HLR that requires an HLR interaction for mobile termination calls. An example of such a service is the "Impediment of any Incoming Call" or "Call Forward". As long as the subscriber activates this service, during the HLR update of the VLR, the indicator is set so that the calls are forced to demand the HLR. As long as these types of services are inactivated, the HLR demand indicator restarts. When the HLR demand indicator is restarted, the VLR contains enough information so that HLR access is not necessary in order to direct the call. It is also included in the HLR 110 together with a profile for a mobile station such as the mobile station 120A, information about the location of the mobile station 120A within the total GSM network. That information is in the form of an identifier 206 of the VLR 112 for the local network 100 within which the mobile station 120 is currently located. As seen in Figure 2, the mobile station 120A and the mobile station 120B are located within the local network area 100 considering that the mobile station 120C, 120D and 120E are within the remote network area 100 '. The mobile stations 120A and 120B are indicated as being located in the VLR 112. The mobile stations 120C, 120D and 120E are indicated as being located in the VLR 112 '. This information is used to direct the software copy of the selected profile information from the local location register 110 to the VLR 112 or 112 'whose network 100 or 100' is the current location for the corresponding mobile station 120. As shown in figure 2, the selected profile information is copied from HLR 110 to VLR 112, according to the geographical information for each respective mobile station 120, stored in HLR 110. The profile for mobile station 120A and 120B which is designated as profile information 202 ', it is stored in the VLR 112. Also stored in the VLR 112 is the demand indicator value of HLR for the corresponding mobile stations. Similarly, the profile information for the mobile stations 120C, 120D and 120E which is referred to as profile information 202 'in FIG. 2, is stored in the VLR 112'. In the VLR 112 'the demand indicator information 204' is also stored for those three mobile stations 120C, 120D and 120E. Turning now to the flowchart of Figure 3, which is better understood with reference to Figure 2, step 301 has the MSC 104 receiving a call from the public switching telephone network 102 which goes to one of the mobile stations 120. Then in step 302, MSC 104 attempts to locate the profile of mobile station 202 'and its corresponding VLR 112. Then in step 304, if the mobile station profile 202 'is located in the VLR 112, then the status of the HLR demand indicator 204' is verified. Then in step 306, if the demand flag of HLR 204 'is set to "yes" which is a binary value of 1, then the MSC 104 initiates the message "send addressing information" to the centralized HLR 110 over the line 113. Alternatively, and according to the invention, in step 308, if the indicator 204 'is set to "no" which corresponds to a binary value of zero, then the MSC 104 completes the call to the station mobile 120, based on the profile information 202 'stored in its local VLR 112. Alternatively, in step 310, if the mobile station profile 202' can not be found in the VLR 112, then the MSC 104 initiates a request to "send addressing information" to HLR 110, on line 113, and MSC 104 then complete the call as indicated by HLR 110 after it copies its profile information to VLR 112, or makes a transfer of information of direct signaling on the line ea 111 towards the MSC 104.

In this way, the signaling traffic between the VLR 112 and the local location register 110 is significantly reduced, thereby increasing the total effective capacity of the GSM network. Turning now to Figure 4, the mobile services switching center (MSC) 104 is illustrated in a block diagram, focusing on the MSC 400 processor. The MSC 400 processor includes a memory 402, connected via the 404 bus to the switching system 406, the communication adapter 408, the second communication adapter 410 and the central processing unit (CPU) 412. The switching system 406 selectively controls the switching between the public switching telephone network 102 through of communication adapter 408, base station controller 106, and base station controller 106A. The second communication adapter 410 controls the interconnection of the MSC 104 with the remote MSC 104 'on the line 109 and the HLR 110 on the line 111. The memory 402 of the MSC 400 processor includes the visitor location register 112 which is a partitioned area of the memory within which profile information may be stored for the visitor mobile stations 120. Also included in the memory 402 is the MSC 105 access which provides the access services between the MSC 104 and the base station controllers , the public switching telephone network, the remote MSC, and the HLR. Also included in the memory 402 is the MSC 300 call processing program whose flowchart is shown in Figure 3. The operating system 450 is also included in the memory 402. All the programs stored in the memory 402 are sequences of Executable instructions running on the CPU 412, carrying out the methods of the invention. Turning now to Figure 5, the prior art data flow between the MSC / VLR and the HLR is observed in detail. In Figure 5, the mobile station is within the local MSC network. In response to an incoming call 501 request from Part A 500, the MSC / VLR 520 sends a request 502 to direct the information to the HLR 530. The HLR 530 sends the addressing information 503. The MSC / VLR 520 sends a acknowledgment 504 for the received addressing information and the HLR 530 sends an acknowledgment 505 for the acknowledgment 504. The MSC / VLR 520 then completes the call 506 to the Part B. It is noted that in each case where places a call between the public switching telephone network and a mobile station, several references have to be made from the MSC / VLR 520 to the HLR 530. Returning now to figure 6, the data flow between the MSC is observed in detail / VLR and the HLR according to the present invention. The mobile station is located within the local MSC network. No need to access between the MSC / VLR 620 and the HLR 630. This significantly reduces the traffic bottlenecks that occur between the MSC / VLR 620 and the HLR 630. In response to an incoming call 601 request from the Party At 600, the MSC / VLR 620 searches 602 in its local VLR, finds the necessary subscriber information for Part B in the VLR and does not send any messages to the HLR 110. The MSC / VLR 620 then completes 603 the call to the Party B 610. In Figure 7, the mobile station is not in the immediate vicinity of the MSC which handles a call between the public switching telephone network and the mobile station. Access must be made between the MSC / VLR 720 and the HLR 730 to obtain the appropriate profile information to redirect the call to the MSC within whose domain the mobile station is currently located. In response to an incoming call 701 from Part A, the MSC / VLR 720 searches 702 on the VLR to direct the information for Part B 710 and finds that the demand bit of HLR is set. The MSC / VLR 720 then sends a request 703 to direct the information to the HLR 730. The HLR 730 sends the addressing information 704. The MSC / VLR 720 sends an acknowledgment 705 for the received addressing information and the HLR 730 sends an acknowledgment 706 for the acknowledgment 705. The MSC / VLR 720 then completes the call 707 to Part B 710. Returning now to Figure 8, this process is shown in more detail. Here, the destination mobile station is not within the service area of the MSC receiving the call from the public switched telephone network. In response to an incoming call request 801 from Part A 800, the MSC / VLR 820 sends a request 802 to direct the information to the HLR 830. The HLR 830 sends 803 the addressing information to the MSC / VLR 820 'where the mobile station for Part B 810 is actually located. The MSC / VLR 820 'sends 804 an acknowledgment for the routing information to the HLR 830, which then passes acknowledgment to the MSC / VLR 820. The acknowledgments 804 and 805 identify the MSC / VLR 820' with the MSC / VLR 820. The MSC / VLR 820 then directs 806 the call to the MSC / VLR 820 'which then completes 807 the call to the Part B 810. Figure 9 illustrates the data flow between the VLR and the HLR for the invention when the mobile station is not within the domain of the MSC that handles the call between the public switched telephone network and the mobile station. In response to an incoming call 901 request from Part A 900, MSC / VLR 920 searches 902 on the VLR for profile information about Part B 910, but can not find it. The MSC / VLR 920 then sends a request 903 to direct the addressing information to the HLR 930. The HLR 930 sends 904 the addressing information to the MSC / VLR 920 'where the mobile station for the Part B 910 is actually located. The MSC / VLR 920 'sends an acknowledgment 905 for the routing information to the HLR 930, which then passes the acknowledgment 906 to the MSC / VLR 920. The acknowledgments 905 and 906 identify the MSC / VLR 920' with the MSC / VLR 920. The MSC / VLR 920 then directs 907 the call to the MSC / VLR 920 'which then completes 908 the call to the Part B 910. In Figure 10, an incoming long distance call 1018 to the local exchange vehicle 1016 (LEC), or an incoming local call 1020 from LEC 1016 activates MSC 1014 to request information about the destination mobile station from local VLR 1012. MSC 1014 does this by sending the number of International ISDN of mobile station 1022 (MSISDN) to local VLR 1012. The destination mobile station is presented within the service area of MSC 1014, so that VLR 1012 returns the identity of international mobile station 1024 (IMSI) and the mobile station's roving number 1 026 (MSRN). With the IMSI 1024 and the MSRN 1026, the MSC 1014 is then able to complete the call. In Figure 11, an incoming long distance call 1018 to the local exchange vehicle 1016 (LEC), or an incoming local call 1020 from the LEC 1016 activates the MSC 1014 to request information about the destination mobile station from VLR 1012. The MSC 1014 does this by sending the international ISDN number of mobile station 1022 (MSISDN) to the local VLR 1012. Here, the destination mobile station is not presented within the service area of the MSC 1014, so that the VLR 1012 returns an unknown subscriber error message 1028. The MSC 1014 then accesses the HLR 1010 when sending the MSISDN 1022 to the HLR 1010. In the same message, the MSC 1014 also sends the mobile station advance number 1030 and the network signaling information 1032 to HLR 1010. HLR 1010 accesses the VLR where the destination mobile station is currently located, here VLR 1008. HLR 1010 sends the IMSI 1024 of the mobile station and the MSISD to VLR 1008. N 1022, the number 1034 of the requested MSC, the support capability of the GSM 1036 and the network signaling information 1032. The VLR 1008 then returns the destination mobile station's roaming number 1026 to the HLR 1010. The HLR 1010 then sends the IMSI 1024 and MSRN 1026 to MSC 1014 which then completes the call. In Figure 12, the HLR demand indicator is presented in the ISD mobile station profiles. An incoming long distance call 1018 to the local exchange vehicle 1016 (LEC), or an incoming local call 1020 from LEC 1016 activates MSC 1014 to request information about the destination mobile station of local VLR 1012. MSC 1014 does this by sending the international ISDN number of mobile station 1022 (MSISDN) to Local VLR 1012. The destination mobile station is presented within the service area of the MSC 1014, so that the VLR 1012 returns the international mobile station identity 1024 (IMSI) and the mobile station roaming number 1026 (MSRN). . With the IMSI 1024 and the MSRN 1026, the MSC 1014 is then able to complete the call. In Figure 13, the HLR demand indicator is presented in the ISD mobile station profiles. An incoming long distance call 1018 to the local exchange vehicle 1016 (LEC), or an incoming local call 1020 from the LEC 1016 activates the MSC 1014 to request information about the destination mobile station of the local VLR 1012. The MSC 1014 does this when sending the international ISDN number of mobile station 1022 (MSISDN) to local VLR 1012. Here, whether the destination mobile station is not present within the service area of the MSC 1014 or the demand indicator of HLR be established in affirmative. If the destination mobile station is not presented within the service area of the MSC 1014, the VLR 1012 returns an unknown subscriber error message 1028. If the HLR demand indicator is set to affirmative, the VLR 1012 returns a message of IR-HLR 1038. In any case, the MSC 1014 then accesses the HLR 1010 when sending the MSISDN 1022 to the HLR 1010. In the same message, the MSC 1014 also sends the mobile station advance number 1030 and the signaling information of the mobile station 1030. network 1032 to HLR 1010. HLR 1010 accesses the VLR where the destination mobile station is currently located, here VLR 1008. HLR 1010 sends to VLR 1008 mobile station IMSI 1024 and MSISDN 1022, number 1034 of the requested MSC , the support capability of the GSM 1036 and network signaling information 1032. The VLR 1008 then returns the destination mobile station rover number 1026 to the HLR 1010. The HLR 1010 then sends the IMSI 1024 and the MSRN 1026 to the MSC 101 4 then complete the call. Although the present invention is illustrated by the GSM protocol, it will be observed by those skilled in the art that GSM is only one of the various mobility protocols. The invention is applicable to any network in which HLRs and VLRs, or similar network elements, are used to track mobility.

Claims (4)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore what is described in the following claims is claimed as property. A method for directing calls from a public switched telephone network to a mobile station within a mobile telephone network, including the mobile telephone network a plurality of mobile telephone stations, a plurality of base stations to communicate with mobile telephone stations , a plurality of mobile service switching centers for directing calls between the base stations and between the base stations and the public switched telephone network, a plurality of visitor location records for storing data in relation to the visiting mobile telephone stations, and at least one local location register for storing all handling data in relation to all mobile telephone stations in the mobile telephone network, the method comprising the steps of: receiving a call directed to a mobile telephone station from a network switching telephone Public n a mobile switching center services; attempting to locate a profile of the mobile telephone station in a visitor location record, the profile having a demand indicator of HLR to indicate whether the local location registration should be requested; verify a status of the HLR demand indicator, if the profile of the mobile telephone station is located in the visitor location record; send a demand message to a local location record requesting addressing information for the call, if the HLR demand indicator is set affirmative; complete the call to the mobile telephone station using the profile in the visitor location record, if the HLR demand indicator is set negative; send a demand message to the local location record requesting routing information for the call, if the mobile telephone profile is not in the visitor location record; and completing the call to the mobile telephone station using the routing information received from the local location register, if a demand message requesting addressing information has been sent to the local location register. The method according to claim 1, characterized in that it further comprises the step of: receiving address information from the local location register. 3. A system for directing calls from a public switched telephone network to a mobile station within a mobile telephone network, including the mobile telephone network a plurality of mobile telephone stations, a plurality of base stations to communicate with mobile telephone stations , a plurality of mobile service switching centers for directing calls between the base stations and between the base stations and the public switched telephone network, a plurality of visitor location records for storing data in relation to the visiting mobile telephone stations, and at least one local location register for storing all handling data in relation to all mobile telephone stations in the mobile telephone network, the apparatus comprising: means, coupled to a public switched telephone network, to receive a call directed towards a telephone station mobile phone from a public switched telephone network; means, coupled to the means of receiving calls and a visitor location register, to try to locate a profile of the mobile telephone station in the visitor location record, the profile having a demand indicator of HLR to indicate whether the location record Local should be requested; means, coupled to the profile location means, to verify a status of the HLR demand indicator, if the profile of the mobile telephone station is located in the visitor location record; means, coupled to the state verification means and a local location register, for sending a first demand message to a local location register requesting addressing information for the call, if the HLR demand indicator is set affirmative; means, coupled to the state verification means, for completing the call to the mobile telephone station using the profile in the visitor location register, if the demand indicator of HLR is set negative; means, coupled to the profile location means and the local location register, to send a second demand message to the local location register requesting addressing information for the call, if the mobile telephone profile is not in the registration of the call. visitor location; and means, coupled to the profile location means, to the state verification means and to the local location register, to complete the call to the mobile telephone station using the address information received from the local location register, if a first or second demand message has been sent requesting addressing information to the local location record. 4. The system according to claim 3, characterized in that it further comprises: means, coupled to the local location register and the call termination means, to receive addressing information from the local location register.