FI92007C - Method for establishing a call in a mobile network, a mobile switching center and a visitor location register - Google Patents

Description

92007

The invention relates to a method for setting up a call in a mobile telephone network comprising at least one mobile telephone exchange, a subscriber database containing the subscriber database and a subscriber register of the subscriber data of the subscriber database of the first visited and registered subscriber registers in the service area of the mobile switching center. in which method: during call set-up, the mobile switching center sends a message to the calling subscriber in which the calling subscriber dials the telephone number of the called subscriber to whom the call from the calling subscriber is to be established, the calling subscriber sends the called subscriber's telephone number to the mobile switching center.

In addition, the invention relates to a mobile switching center comprising: means for transmitting messages from a mobile link center via base stations to subscribers, means for directing and connecting calls from a calling subscriber to a called subscriber, means for transmitting messages between a mobile switching center and a mobile telephone.

The invention further relates to a visitor register of a mobile telephone system, which comprises: a subscriber database for storing subscriber information of subscribers;

Various cellular radio or cellular telephone systems are currently in use and planned, in which the geographical area covered by the system is divided into smaller 2,2007 separate radio regions, i.e. cells so that while in the cell, the radiotelephone or cellular telephone communicates with the fixed cellular elements of the mobile telephone network. The mobile phones in the system are free to move from one cell to another in the system. Eras such a system is the digital mobile phone system GSM (Global System for Mobiles). Typically, in such cellular radio and mobile telephone systems, calls are routed and connected from one subscriber to another by means of mobile services switching centers (MSCs) and forwarding. However, the mobility of subscribers in the area of the cellular and mobile telephone system requires certain conditions for the operation of the system.

15 The mobility of subscribers made possible by modern cellular radio and mobile telephone systems is based on the fact that a network component has information about where each subscriber in the network is located at any given time. In this case, incoming calls, or other telecommunication messages or telecommunication services, can be routed to the subscriber in question, if the subscriber in question is to be called.

Information about the subscriber's location is usually stored. subscriber database, which also contains subscriber-specific information on the services available to the subscriber. The subscriber database is conventionally implemented in registers comprised by the mobile telephone network, for example in the GSM system in the Visitor Location Register (VLR), which stores the Traffic LLs of the subscribers of each subscriber located in the VLR service area of the VLR service area. The GSM system also has a Home Location Register (HLR), in which the VLR identifier of the visitor register in the territory of which each subscriber is currently located is stored for each subscriber.

I i 3 92007

Figure 1 shows a signaling diagram of a prior art routing information query. The left side of the figure shows a base station system BSS with base station controllers and base stations, as well as subscribers connected to the base stations via radio-5. In the prior art solution, calls are routed from the calling subscriber to the called subscriber in such a way that the calling subscriber sends a connection request to the mobile telephone network and setup the called subscriber identifier, typically the called subscriber's telephone number, i.e. the GSM system. (Mobile Station international PSTN / ISDN Number) for the mobile switching center MSC of the mobile telephone network. Thereafter, in the base station system 15, the BSS allocates a communication channel, e.g., a radio channel, to the calling subscriber and notifies the mobile switching center MSC by sending an As-signmentComplete message 101. Next, when the mobile switching center B number, then the call switching and control block of the mobile switching center MSC analyzes the given telephone number of the called subscriber and detects that the call is directed to the mobile telephone of the mobile telephone system in question. In this case, the mobile switching center MSC initiates a query of the call-25 routing information from the home directory of the called subscriber by means of the MAP protocol (MAP = Mobile Application Part) of the HLR mobile telephone system. This is done in the GSM system according to the standard "GSM 09.02 version 3.8.0, January 1991, Mobile Application Part Specification 30 DCS, ETSI, section 5.4.2.3". In this case, the mobile switching center sends a routing information request message 102 (SendRouting information) containing the MSISDN number of the called subscriber to the home location register HLR, which retrieves the information of the called subscriber from the subscriber database 4 with the location information of the called subscriber. Thereafter, the home location register HLR requests by sending the roaming number request message 103 (Provi-deRoamingNumber) from the visitor location register VLR, the identity of which the home location register HLR has received as the location information of the called subscriber 5 from its database MSR

Mobile Station Roaming Number). The roaming number is used as routing information to route the call to the called subscriber. The roaming number contains information on which VLR area of the visitor register the called subscriber 10 in question is as well as an identifier reserved for this called subscriber during the call set-up. The visitor location register VLR sends the roaming number of the called subscriber as a message 104 (RoamingNumber) to the home location register HLR of the called subscriber. When the home location register HLR has received the roaming number from the tracker register VLR, the home location register HLR forwards the roaming number to the mobile services switching center MSC requesting it by sending a routing information inquiry message 102 to the mobile services switching center MSC. Thereafter, the call switching and control block 20 of the mobile switching center MSC receives the routing information contained in the roaming number and analyzes it. If the result of the analysis is that the called subscriber is roaming in the VLR area of the "own" visitor register in question, the requested mobile switching center MSC visited starts paging the called subscriber. After the subscriber search process and any associated subscriber identification. 30 (identification) and authentication (Authentication) have been successfully completed, the visitor location register VLR sends the subscriber information via the register interface block of the mobile switching center MSC to the call switching and control section, which checks the services allowed for that subscriber 35 and if the called subscriber can be connected, .: 5 92007 connect to the called subscriber the telecommunication service, for example the voice channel, which is to be connected to the called subscriber. At the same time, the visitor location register VLR releases the roaming number of the called subscriber for new use, after receiving the Sendlnfo-ForlcCall message 106 sent by the mobile switching center MSC.

The problem with this known prior art method and its implementing system is that if the called subscriber is in the service area of the same visitor location register VLR 10 in which the calling subscriber is also located, then all the information needed to route a call or other telecommunication service from the calling subscriber to the called subscriber are in the visitor location register VLR, so the system will ask them unnecessarily for the home location register 15 HLR. In this case, the home registry still requests the roaming number from the visitor location register VLR, which sends the roaming number to the visitor location register for further transmission to the mobile switching center in whose service area the subscribers in question are located. As a result, a large amount of unnecessary signaling and messaging traffic is created in the mobile phone-20 network, which consumes the signaling capacity of the mobile phone network. At the same time, the mobile home network register and the visitor register are overloaded with unnecessary location information queries.

A further disadvantage of the prior art is that if the mobile network is so small in subscriber size that the data of all its subscribers can fit in one visited register VLR, the mobile network must still have a home register, although subscribers can only move in one VLR area, and to the mobile switching center of the calling subscriber only one visitor location register VLR as routing information when the mobile switching center wants to route the call to the called subscriber. Naturally, there are an unnecessary network element in the mobile network in the mobile network.

The object of the present invention is to enable the simplest possible connection establishment method for establishing a telecommunication connection between a calling and a called subscriber located in the VLR service area of the same visitor location register. In this case, unnecessary signaling traffic and unnecessary home location register HLR are avoided if there is only one visitor location register VLR in the network.

This novel method and systems for generating speech Wong mobile telephone network is achieved KEK-10 sinnonmukaisella method using which is characterized described in the following, to menetelmåvaiheista: a mobile switching center pyytåå låhettå, denying the subscriber information request message of its own, ensimmåistå visited register maintained låhettåmåån the called subscriber's subscriber data from the mobile switching center, first visitor location register 15 searches the called subscriber information about the subscriber data isthmus -the first register of visitors sends a subscriber information inquiry message acknowledgment message to the mobile switching center.

This new type of system for making a call in a mobile telephone network consists of at least one new-20 type mobile switching center, characterized in that the mobile switching center further comprises a selected called subscriber for retrieving the connection number contained in the phone number.

This new type of system for making a call in a mobile telephone network further consists of at least one new type of visitor register, which is known. 30 that it comprises means for retrieving the subscriber's subscriber information from the subscriber database on the basis of the called subscriber's telephone number in response to a subscriber information query sent by the mobile telephone link center.

The invention is based on the idea that when the kut-35 Suva subscriber has sent an MSC message to the mobile switching center «

I I

7 92007 the telephone number of the subscriber called via the base station system BSS, so that instead of the mobile switching center asking the home location register HLR of the called subscriber of the called subscriber in which the called subscriber is located, this is done as follows. The mobile switching center MSC always first queries the called subscriber's ti-wide information from the visitor location register VLR in whose service area the calling subscriber is located, and if the called subscriber's information is found in the subscriber database of that visitor-10 register. -le. If, on the other hand, the information of the called subscriber is not found during this query from the visitor register, the mobile switching center MSC queries the home register HLR of the called subscriber for the ID of the visitor register, i.e. the location information of the called subscriber in whose service area the called subscriber is located. To answer this question, the home registry requests a roaming number from the visitor location of the called subscriber's location area 20 and, after receiving it, the home registry transmits that roaming number to the mobile switching center, which establishes a communication link between the calling and called subscribers. That is, in this case, after the mobile switching center has requested the called subscriber 25 information from the visitor location register, the operation is performed in the same manner as in the prior art case.

An advantage of such a method and system for making a call in a mobile telephone network is that the invention avoids unnecessary signaling traffic and unnecessary querying of the called subscriber's information from the home directory if the called subscriber's information is in the same caller register in the service area. In this case, the load on the visitor location register VLR also decreases, since the home register HLR of the called subscriber does not query 35 roaming numbers from the visitor location register. This is particularly the case when the majority of subscribers to a mobile telephone network are in the service area of the same visitor register. In this case, a reduction in the load on the subscriber's home register is also achieved.

5 An additional advantage of the invention is that if fixed mobile telephones or wireless subscriber lines (DAL, Drahtlose Anschlussleitung, wireless Subscriber line) are to be connected to the mobile switching center, the routing information of which is always the same and which are called by subscribers are in the service area of the same visitor register as the fixed subscribers in question, so that in order to transfer calls between these subscribers it is not necessary to request the routing information of the called subscriber from this home location register HLR. The use of such fixed mobile telephones or wireless subscriber connections is particularly advantageous in areas where it is desired to quickly build the necessary subscriber connections.

The invention will be described in more detail below with reference to the accompanying drawings, in which Fig. 1 shows a signaling diagram of a prior art routing information query, Fig. 2 shows a signaling diagram of a subscriber information query according to the invention, in the visitor location register in the service area of which the calling subscriber is located, Fig. 4 shows a block diagram of a mobile switching center according to the invention and a visitor location register, FIG.

Figure 1 shows a signaling diagram of a routing information query according to the prior art 9 92007. The description of Figure 1 is in the general part of the description of this patent application.

Fig. 2 shows a signaling diagram of a subscriber data query according to the invention, the network-5 test elements shown in the figure are the same as the network elements shown in Fig. 1. According to Fig. 1, after the calling subscriber has sent a connection establishment request to the mobile switching center MSC via the base station system BSS and when the communication channel is reserved for the calling subscriber and the reservation is notified by saying 201 to the mobile switching center MSC, the operation according to the invention begins. The mobile services switching center MSC sends a subscriber information message (IS_THIS_SUBSCRIBER_KNOWN) 202 to the visitor register of the calling subscriber, i.e. to the first visitor register VLR1, which contains the MSISDN number of the called subscriber as 15 parameters. The visitor register VLR1 retrieves the location information of the called subscriber from its subscriber database and if it is in the subscriber database the visitor register VLR1 sends the called subscriber information to the subscriber information inquiry message the connection of the telecommunication connection between the calling and the called subscriber. If the information of the called subscriber is not in the subscriber database of the guest register VLR1, the guest register VLR1 is sent to the mobile switching center MSC in the acknowledgment message of the negative subscriber information inquiry message (UNKNOWN_SUB-SCRIBER), which is described in connection with

Fig. 3 shows a signaling diagram of a routing information query according to the invention in the case that the information of the called subscriber is not in the first, visitor register VLR1 in the service area of which the calling subscriber is located. Figure 3 up to message 303 is similar to Figure 2 up to message 203. That is, message 301 corresponds to message 201 and message 302 corresponds to message 202. Since the first visitor register VLR has not found the called subscriber information in the subscriber database and the visitor register VLR1 has sent a negative subscriber information inquiry-5 the routing information query message 304 (Sen-dRoutinglnformation) corresponding to the message 102 of Fig. 1 to the home directory HLR of the called subscriber. This interrogation of routing information from the home directory, subsequent retrieval of the roaming number from the second visitor location register VLR2, transmission of the roaming number to the mobile switching center MSC and connection establishment between the calling and called subscriber is otherwise the same as described , for the description of Fig. 1, but in this case the second visitor register VLR2 acts as the visitor register. The subscriber database of this second visitor register thus contains the location information of the called subscriber. Thus, in Fig. 20, message 305 corresponds to message 103, message 306 corresponds to message 104, message 307 corresponds to message 105, and message 308 corresponds to message 106. Likewise, as a result of querying the routing routing information, the mobile switching center MSC establishes a communication connection between the calling subscriber and the called subscriber.

Figure 4 shows a block diagram of the mobile switching center MSC 414 and the visitor location register VLR 415 and some associated network elements, i.e. the base station controller BSC 413 and the home location register HLR 412. The mobile switching center MSC connects to , through which subscribers connect to the mobile telephone network. Associated with the A-interface 401 is a mobile switching center call switching and control block 402 which performs call connection and call control (callcont-35 roll) and a register interface block 403 which performs information transmission between the mobile switching center MSC and the subscriber registers, e.g. With VLR. In the implementation according to the invention, the call switching and control block 402 is associated with an inter-call set-up control block 55, the function of which is to send the subscriber information inquiry message 202 shown in Fig. 2 to the visitor register, the subscriber of the mobile network in question. The intercom establishment control block 405 is connected to the mobile part MAP 406, by means of which the mobile switching center 10 communicates with, inter alia, the home location register HLR 412. The visitor location register VLR also has a mobile part MAP 411, by means of which the visitor location register VLR 415 communicates with the home location register HLR 412. The mobile switching center MSC connects to the visitor register VLR 415 via the register interface 403 and the intercom establishment control 15. The visitor register VLR has a subscriber database 410 in which the information of the subscribers in the service area of the visitor register VLR is stored. The subscriber database can be read and stored therein by means of a data processor 209 associated with the subscriber database 410. The database processor 409 is controlled by the VLR subscriber operations control 408, which is connected to the registry interface 403 of the mobile switching center MSC. a signal transmitted from the MSisdn processor 407 to the database processor 409, which in the case of the invention is able to retrieve information about this subscriber from the subscriber database 410 based on the MSISDN number of the called subscriber. or blocking incoming calls, are retrieved from the subscriber database in the subscriber database and returned in an acknowledgment message via the MSisdn handler 407 to the call set-up control 405, which transmits the data to the mobile caller. a link center MSC for call switching and control block 402, which performs the connection of the communication connection between the calling and the called subscriber. If, on the other hand, the subscriber-5 database 410 does not have the called subscriber information, the MSisdn handler 407 sends a subscriber information query message to the mobile call center MSC for intercom establishment control 405 , sending the routing information query message 304 (SendRou information) shown in Fig. 3. Thereafter, the operation continues as described in connection with Figure 3. Regarding the implementation of the mobile switching center MSC and the visited register VLR, it should be noted that they can be implemented as a single network element to which even the home location register HLR can be connected.

Figure 5 shows an example of a prior art connection established by means of a block diagram. The calling subscriber 50 sends 501 the call set-up request contained in the MSISDN number of the called subscriber 20 via the system BSS to the mobile switching center MSC. The mobile switching center MSC requests 502 the information of the calling subscriber A from the visitor location register, which sends 503 it to the mobile switching center MSC. Thereafter, the mobile switching center 25 requests 504 the routing information of the called subscriber from the home location register HLR, which requests 505 roaming numbers from the visitor location register VLR, and if the calling and called subscribers are in the service area of the same visitor location register The visitor register sends 506 the roaming number to the home location register HLR which sends 507 its routing information to the mobile switching center MSC. Thereafter, the mobile switching center requests 508 from the visitor location register VLR called subscriber information, which is transmitted 509 to the mobile switching center MSC. The mobile switching center then establishes a desired communication connection between the calling subscriber A and the called subscriber B.

Figure 6 shows a block diagram of an example of a connection according to the invention implemented by means of a block diagram.

The calling subscriber A sends a call set-up request containing the MSISDN number of the called subscriber 601 via the base station system BSS to the mobile switching center MSC. The mobile station MSC requests 602 the information of the calling subscriber A from the visitor location register VLR, which sends 603 them to the mobile station 10 MSC. The mobile switching center then asks 604 whether the called subscriber is known from the visitor location register VLR, which sends 605 information that the subscriber is known as well as information about the subscriber's possible immediate call transfer or incoming call barring information to the mobile switching center MSC. Thereafter, the mobile switching center MSC requests 606 from the visitor location register VLR the information of the called subscriber B, i.e. for example information about possible additional services of the subscriber, for example conditional call forwarding, which may be subscriber unreachable -20 call forwarding, subscriber not answering call forwarding, call forwarding or from the queuing service. The visitor location register VLR 607 transmits this information to the mobile services switching center MSC, which establishes 608 the desired communication connection.

The drawings and the related explanation are only intended to illustrate the idea of the invention. The details of the method and system for establishing a call in a mobile telephone network according to the invention may vary within the scope of the claims. Although the invention 30 has been described above mainly in connection with a GSM system, the method according to the invention, the mobile switching center and the visitor location register can be used in other types of cellular radio systems.

Claims (5)

A method of establishing a call in a mobile telephone network comprising at least one mobile telephone exchange 5 (MSC, 414), an understanding visitor register (VLR1, 415) with a subscriber database (401) for storing the service area of the mobile telephone exchange (MSC, 414) subscriber (A, B) subscriber data and a home directory (HLR, 412) for storing subscriber (A, B) routing data with a visitor register (VLR, 415) accuracy and forwarding to the mobile telephone exchange (MSC, 414), in which procedure: the mobile telephone exchange (MSC, 414) sends a message to a calling (A) subscriber during the call request, in which the calling (A) subscriber is asked for the called (B) subscriber's telephone number, to which the subscriber calls from the calling (A) ) the subscriber must be connected, the calling (A) subscriber sends the called (B) subscriber's telephone number to the mobile telephone exchange (MSC, 414), the mobile telephone exchange (MSC, 414) switches a data communication channel al from the calling (A) subscriber to the mobile telephone exchange (MSC, 414), the method being further annotated by the following step: by requesting such a subscriber data request message (202) the mobile telephone exchange (MSC, 414) , understand visitor register (VLR1, 415) so that the called (B) subscriber's subscriber data to the mobile telephone exchange (MSC, 414), understand the visitor register (VLR1, 415) searches the called (B) subscriber's subscriber data in its subscriber database (414), 35 it understands the visitor register (VLR1, 415) sends to * * 18 92007 the mobile telephone exchange (MSC, 414) a receipt message (203) to the subscriber data request message. The method of claim 1, characterized in that, when the subscriber (B) subscriber's subscriber data is in the understand visitor register (VLR1, 415) subscriber database (410), it locks the understand visitor register (VLR1, 415) the called ( B) the subscriber's subscriber data from its own database (410), understanding the visitor register (VLR1, 415) transmits the called (B) subscriber's subscriber data to the mobile telephone exchange (MSC, 414) in the receipt message (203) to the subscriber data request message, the mobile telephone exchange (MS) (510) establishes a connection between the calling (A) subscriber and the called (B) subscriber. The method of claim 1, characterized in that when the called (B) subscriber is within a second visitor register (VLR2, 415) service area, the subscriber data of the called (B) subscriber is not in the understanding of the subscriber register ( VLR1, 415) subscriber database (410), but in the second visitor register (VLR2) subscriber database (410), it understands visitor register (VLR1) to the mobile exchange (MSC, 414) a denial acknowledgment message (303) to the subscriber request message, MSC, 414) sends a routing request message (304) to the called (B) subscriber's home register (HLR, 412), the called (B) subscriber's home register (HLR, 412) sends a roaming number request message (305) to the second visitor register (VL2). ) within our service area the called (B) subscriber is located, the second visitor register (VLR2) transmits the calling subscriber's roaming number (3). 06) to the called (B) subscriber's home register (HLR, 412), the home register (HLR, 412) sends the roaming number to the mobile telephone exchange (MSC, 414), the mobile telephone exchange (MSC, 414) establishes a connection between the calling (A) subscriber and the called (B) subscriber. Mobile telephone exchange (MSC, 414), comprising: means (401) for conveying messages from the mobile telephone exchange via base stations (BSS, 413) to subscribers, means (402) for controlling and switching calls from a caller (A ) subscriber to a called (B) subscriber, means (403, 406) for conveying messages between the mobile telephone exchange and the visitor's register of the mobile phone system and home register, characterized in that the mobile telephone exchange also comprises a means (405) for the request of the called subscriber 20 subscriber data in the visitor register (VLR, 415) subscriber database (410) on the basis of the called (B) subscriber's telephone number in response to one of the calling (A) subscriber's sand, in the called (B) subscriber's telephone number request connection connection request (501). 5. Visitor register (VLR, 415) in a mobile telephone system, comprising visitor register: a subscriber database (410) for storing subscriber data on subscribers (A, B), a database manager (409) for locking and storing subscriber data on the subscribers (A, B) in the subscriber database, a subscriber functions controller (408) for conveying messages between mobile telephone exchanges (MSC, 414) and the subscriber database manager (409), the visitor register (VLR, 415) being characterized accordingly; 9 2 0 0 7 further comprising means (407) for searching subscriber data about the subscribers in the subscriber database (410) on the basis of the called (B) subscriber's telephone number in response to one of the mobile telephone exchange (MSC) true request for subscriber data (202). • «