FI112770B - A mechanism for mobility management in telecommunications networks - Google Patents

Description

112770

A mechanism for mobility management in telecommunications networks

Background of the Invention

The invention relates to telecommunication technology, and in particular to mechanisms supporting mobility management in telecommunication networks.

5 In mobile networks, the increasing number of subscribers, the reduction of cell sizes and the diversification of services increase the need to update subscriber databases and the number of location queries. Location information can be considered as the fastest changing information in subscriber data. In addition, as network size increases, subscriber mobility requires the storage of subscriber data and location information in a centralized location information database HLR (Home Location Register) and a VLR (Visitor Location Register) element of a service control center. New, growing volumes of data require greater processing and disk backup power to control terminal mobility, which is not provided by current central technologies.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is thus to provide a new mechanism for controlling mobility in telecommunication networks.

The object of the invention is achieved by a method and a system characterized by what is stated in the independent claims. Preferred embodiments of the invention are claimed in the dependent claims appended.

The invention is based on providing a packet network name server and an address server for the management of radio subscriber location information in a telecommunications network. When a subscriber signs up for a network service, the subscriber is allocated an IP address from the address server. One or more name identifiers have been or will be reserved from the name server upon registration to indicate the subscriber. The new IP address is updated to the name server, from which other network nodes may in future request the subscriber's IP address with one or more name identifiers reserved for the subscriber. Thus, the name server allows the subscriber to be called by many nicknames, even if the IP address changes sufficiently when the subscriber's location changes within the network '· * ·'.

The invention provides additional capacity for managing location data; 'Simply because, when a subscriber signs up for a network, there is no need to update any information in the central subscriber directory. However, a centralized subscriber directory can verify the subscriber's right to use network services. An advantage of invention 112770 2 is that standard IP protocols and devices can be utilized in the implementation of location management.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described in connection with preferred embodiments 5 with reference to the accompanying drawings, in which:

Figure 1 illustrates the storage of subscriber data and location data;

Figure 2 shows an update of a subscriber's location information;

Figure 3 illustrates call control for a B-subscriber;

Figure 4 illustrates a caller's return to a new location center;

Fig. 5 shows an operator-controlled subscriber information update; and Figure 6 illustrates a group-controlled update of a group information.

DETAILED DESCRIPTION OF THE INVENTION

Although the invention and its preferred embodiments will be described below in connection with TETRA (TErrestrial Trunked RAdio) and IP (Internet Protocol) systems, the basic principles of the invention can be implemented in any telecommunication system using at least one subscriber database to control subscriber mobility. These communication systems include e.g. dedicated radio networks PMR (Private Mobile Radio) and PAMR (Public Access 20 Mobile Radio), Public Land Mobile Network PLMN 'and / or Public Switched Telephone Network PSTN.

The TETRA system is a digital communication system, which has been developed for public transport purposes, for example. the police and the armed forces (for public safety and security). A typical TETRA system basic network architecture comprises digital exchanges (DXT) to which access points (TBS, TETRA Base Station) are connected. The TETRA system may use a distributed subscriber database structure, i.e., it may have a HLR and / or a Home Database (HDB) which contains persistent subscriber and / or group 30 related information in the subscriber's home network, and a VLR visitor and / or visitor database VDB ) which includes temporary information about the subscriber and / or group visiting the network. Each DXT element may have a VLR / VDB element. Some DXT exchanges act as gateways or gateways to other telecommunications networks.

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However, since the invention is not directed to the operation and / or structure of the TETRA system as such, they have been described, or to the extent that they help to understand the invention. For a more detailed description of the TETRA system, reference is made to the European Telecommunications Standards In-stitute (ETSI) specifications, which are available, for example, at www.etsi.org.

An IP system refers to an Internet-type communications network in which a message is transmitted from sender to recipient using an IP protocol. In such networks, the IP protocol is the actual network protocol whose function 10 is to route an addressable IP message from the source station to the destination station. The TCP / IP (Transmission Control Protocol / Internet Protocol) protocol, which serves as an Internet communication protocol, has the particular advantage of being independent of various hardware and software architectures.

Data transfer over Internet networks is packet-switched data-15 transfer. In it, the information is transferred in chunks to packets, each of which contains, in addition to the payload, source and destination addresses. Each packet is routed through the packet switched network independently on the basis of said address information. Thus, data packets related to the same communication can travel on different paths and with different delay from source to destination depending on network load.

20 There are various configurations of how the TETRA system DXT can be connected to an IP system communication network. In one configuration, each DXT unit may have its own direct:: '' exit '' path through an adjacent router to forward IP packets. . From the TETRA network to the Internet and vice versa. The router can be used to connect, ··. 25 denotes a device at a node in a telecommunications network, a network drive; software and / or software that can address information transmitted over an address to another, possibly different, network. In one configuration, '' only one or a few DXTs, which can be called gateway DXTs, are connected to an Internet-V 30 router, and other DXTs are connected to the Internet by their gateway - .., 1 Through DXT elements. Each exchange DXT may form its own IP subnet having its own local IP address space, as in the example of Figure 1. Similarly, an IP subnet may comprise two or more exchanges DXT, which thus have a common local address space. An IP packet with an IP address belonging to the local address space of the IP-35 subnet is routed to that subnet.

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Figure 1 illustrates the storage of subscriber data and location information of a TETRA system according to the invention and preferred embodiments thereof. The subscriber database is in the HLR home directory. Any changes to the information as well as the Subscriber's First Registration of the subscriber to Operator will be done en-5 internally there. Typically, the information consists of various terminal numbers and IDs, the calling and receiving rights of the subscriber, and additional services activated for the subscriber. However, in the system of the invention, the home location subscriber information does not include location information as in prior art implementations.

10 Depending on the size of the network, the number of subscribers, and the service types, there may be several HLRs. These registers can share the load based on the number of subscribers, the types of services, or any other method of distribution that optimizes data management. In a large network, there may be visitor location registers VLR in addition to HLRs. The exchange and the VLR can also be combined into one network element.

In a preferred embodiment of the invention, mobile network mobility management comprises, in addition to the elements mentioned above, an address server called Dynamic Host Configuration Protocol (DHCP) which serves to allocate IP addresses to subscribers upon request of exchanges. Subscriber location updates are made to the DHCP address server. The network may also include a Domain Name Server (DNS) 20, which allows multiple names to be called by a terminal, for example a mobile station MS, although the IP address changes as the subscriber's location changes. Name server DNS performs name-to-address conversions. The name server DNS and the address server DHCP can be combined into the same element.

·. Preferably, all of the elements described above are connected to one another by IP; over a packet switched network, commonly referred to as an IP network, that supports protocol and IP address based IP packet routing. An IP network can be, for example, an operator's Intranet, a local area network LAN, or even the Internet. The message exchange 30 associated with the mobility management according to the invention is performed over an IP network. Instead, the actual calls can be established either in a circuit-switched (e.g. TETRA) or packet-switched (e.g., Voice over Internet Protocol (VoIP) call).

When a radio subscriber signs up for a network service, the subscriber station is allocated an IP address from the address server DHCP. On the other hand, nameserver DNS 35 may have been reserved or reserved, for example, upon registration, with identifiers such as MSISDN (Mobile Station ISDN Number), ITSI

112770 5 (International TETRA Subscriber Identity), short number and name to identify subscriber. The new IP address will be updated for the DNS name server so that the subscriber can be further identified with the reserved identifiers in addition to the IP address. In other words, the identifier or identifiers can be permanently added to the name server when the subscriber is created and / or temporarily, for example, during registration. An example is the situation in which an identifier can be sent from a subscriber in a message requesting registration. Alternatively, for example, the HLR element may be requested for the identifier (s), for example, when the nameserver is temporarily holding identifiers.

Figure 2 shows an update of a subscriber's location information. When the subscriber changes its location to the area of the new location center DXT_1 in step 1, in steps 2 and 3, the exchange DXT1 may first check the subscriber's home location register HLR for access to the network services. Instead, the DXT_1 does not provide information about the location of the subscriber to the home location register HLR, as is the case with traditional systems. After a possible authentication, comparison of authentication challenges, the exchange can establish an IP connection in step 6 using the subscriber identifier to the old location center DXT 2. During the connection, the IP address corresponding to the subscriber's name may be requested from the DNS to the old location center. DXT_2 based on that van-20's IP address. In the message, the exchange can announce the new location of the subscriber. The old location center DXT_2 can delete the subscriber information in the register; · Send and possibly send to the new exchange DXT_1 in step 7 information about the subscriber, such as the groups to which the subscriber has joined. Thus, the connection to the old location center DXT_2 can be obtained entirely by means of the IP network elements without measuring the home location register. Finally, location center DXT_1 may request a new address from the address server DHCP for the subscriber MS_1. If the IP subnet has changed, the DHCP address server can assign a new address to the subscriber and update the information to the name server. At this point, information on the subscriber's previous location center DXT_2 can also be deleted. It is also possible to update the new 30 VLR information to the HLR register.

The subscriber can always be assigned a new IP address from the Location Center subnet, after which the IP network routers can automatically deliver the data packets to their destination. The address can be reserved using the standard DHCP protocol on the Internet. The address is assigned by the DHCP protocol-35 server. In addition, the subscriber is provided with the required set of identifiers for the Internet 112770 6 standard name server DNS. This element maintains information about the corresponding IP addresses.

Examples of practical identifiers are ISSI7000200, which can be generated when a subscriber signs up for network or caller selection.

Similarly, identifiers can be generated in any way that the subscriber must be reachable from the network, such as MSISDN0405384208, FSSN65977, TAPIOLA00230. You can also tag your home registry in the same way. For example, if one HLR is the home location register for all ISSI (Individual Short Subscriber Identity) numbers beginning with 6 and 7, two names HLR6 and HLR7 may be reserved for the home location register. In this case, the connection between the exchanges and the operator / duty system is simply done by name.

Figure 3 shows a call control to a B subscriber. Since, in the case of Figure 3, the A-subscriber's call is to another mobile subscriber, the A-subscriber exchange DXT_1 may form an IP host name from a number selected by the A-subscriber.

The exchange DXT_1 can start the IP connection to the subscriber, whereupon the name server can be asked in step 2 for the IP address corresponding to the B-subscriber identity. Based on the address retrieved in step 3, the IP network can route messages to step B DXT_2 in step 4. For example, routing can take place through one or more gateway elements. The call can then be made in step 5 through the central network to the DXT 3 of the B-subscriber center. : ': Can be done, for example, based on subscriber data copied to the local directory VLR_3.

, ·· *. Thus, in the system of the invention, the call can be made without encumbering the subscriber's home location registers HLR. Messages are routed automatically to the exchange using routers on the IP network. A call from subscriber A to subscriber B can be established either as a circuit-switched (e.g., TETRA call) or packet-switched (e.g., VoIP (Voice over Internet Protocol) - '30 call).

Figure 4 illustrates the return of a subscriber call to a new location center. When a subscriber changes location while a call is in progress, callback can be requested at the new location center DXT_1.

Initially, in steps 2 and 3, the exchange DXT_1 can check the subscriber's right to access network services from the subscriber's home location register HLR. Thereafter, in step 6, the exchange DXT_1 can establish an IP connection using the subscriber identifier 112770 to the 7 old location centers DXT_2. Prior to making this connection, the IP address corresponding to the subscriber's name may have been requested in steps 4 and 5 from the DNS. The IP network can route messages to the old location center DXT_2 based on the IP address. In the message, the exchange DXT_1 may indicate the subscriber's new location and may also request a call return. The old location center DXT_2 may delete the subscriber information from its register and may, in step 7, send some information about the subscriber to the new exchange DXT_1, such as groups to which the subscriber has joined and information about the ongoing call such as information about another subscriber. Thereafter, location center DXT_1 may, in steps 8 and 9, request a new address for the subscriber from the address server DHCP. If the IP subnet has changed, the DHCP address server may assign a new address to the subscriber and update the information / data to the name server.

In step 10, the central DXT_1 can form a center location of the second party's IP connection DXT_3 received a call using the IP address. 15 When establishing a connection, the IP address corresponding to the subscriber's name can be requested from the name server, and the IP network routes the messages to the old location center based on the IP address of the DXT-2. The call can then be connected through the central network to the new location center DXT_1.

Thus, in the system of the invention, the call can be restored without encumbering the subscribers' home registers. Messages are routed automatically to the correct exchange using routers on the IP network. On the other hand, IP network ·, ·; heavy IP packet tunneling, for example by mobile IP technology, is not required:: i: Vita because the subscriber is asked for a new address in the new location center which::: informs the other party of the call.

Figure 5 illustrates an operator-controlled subscriber information update.

. ,: Operator modifications to subscriber information can be made to the home directory HLR of the subscriber information in step 1. The HLR may establish an IP '' 'connection to the subscriber location center VLR by means of the subscriber identifier in step 4. In establishing a connection, the IP address corresponding to the subscriber's name may be requested from the name server DNS in steps 2 and 3, and the IP network may route messages to the location center and the local register based on the VLR IP address. Local; ' ". the additional register VLR may acknowledge in step 5 the changes to the home location register HLR.

. . . ; When creating a new subscriber, the home location register HLR does not need to export data to the local location register VLR. Instead, the subscriber names can be created for the DNS server.

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Figure 6 illustrates a group-controlled update of a group information. When the duty officer changes group information in step 1, the changes can be made directly to the home location register HLR. In step 4, the home location register may establish an IP connection to the local location register VLR of the subscriber's location center using the subscriber identifier.

5 When establishing a connection, the IP address corresponding to the subscriber's name may be requested from the name server in steps 2 and 3, and the IP network may route the messages to the location center based on the IP address. The local register VLR may acknowledge the changes to the home location register HLR in step 5.

In the invention, IP technology can be applied for storing location information and querying location information 10. Delivered in this manner, most of the centralized subscriber directory update load, e.g., location updates, can be delegated to elements using IP technology. With the power of IP technology, powerful hardware and standardized development and application tools are available. According to the invention, an IP network name server DNS and an address server DHCP for managing radio subscriber location information can be provided to the mobile network, as described above.

When the subscriber registers to the network according to the invention, the centralized subscriber directory HLR does not need to update the information. In conventional systems, the home location register maintains subscriber-specific location information, and the register 20 also updates the subscriber's new location. Thus, the invention provides the advantage that the capacity and / or number of HLR registers are available. There is no need to add the network, as in prior art solutions:: for example in the GSM system, is done. The invention thus found can: · ': easily obtain additional capacity for managing location information.

In addition to the above examples, the invention and its preferred; other network, telecommunication and / or auxiliary services of telecommunication systems may also be used with the embodiments.

It will be obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in many different ways. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims.

Claims (13)

1. A method of mobility control in a telecommunications network, comprising subscribers (MS A, MS_B), serving network nodes (DXT_1, DXT_2, DXT_3) and at least one home directory (CPR), where subscribers' data (MS_A, 5 MS_B) subscriber data is stored permanently, characterized by subscriber (MS_A, MS_B) location data is checked using an IP name server (DNS) and an IP address server (DHCP), messages are transmitted between the name server (DNS), the address server (DHCP) and the serving nodes (DXT_1, DXT_2, DXT_3) via an IP network, at least one identifier is reserved for the subscriber (MS_A, MS_B) from the name server (DNS) for indicating the subscriber (MS_A, MS_B), an IP address is allocated to the subscriber (MS_A, MS_B) from the address server ( DHCP) when the subscriber (MS_A, MS_B) for the first time registers in any of the serving network nodes (DXT1, DXT_2, DXT_3) in a new IP subnet, the new IP address is updated in the name server (DNS), of which the serving the network nodes (DXT_1, DXT _2, DXT_3) can request the subscriber's (MS_A, MS_B) IP address using the at least one subscriber-reserved name identifier. 20 2. A method according to claim 1, characterized in that at least one identifier is reserved in the name server (DNS) when the subscriber (MS_A, MS_B) is created. Method according to claim 1, characterized in that at least one identifier is reserved in the name server (DNS) when the subscriber (MS_A, MS_B) registers in the network. Method according to any of claims 1-3, characterized in that updating the subscriber's (MS_A, MS_B) location data comprises steps where a new serving node (DXT_1, DXT_2, DXT_3) checks the subscriber's (MS_A, MS_B) rights through a query to the subscriber's home directory (CPR) where the subscriber (MS_A, MS_B) switches the servicing node (DXT_1, DXT_2, DXT_3), the new serving node (DXTJ, DXT_2, DXT 3) requests the subscriber's (MS_A, MS_B) IP address of the name server ( DNS) using the name identifier reserved for the subscriber (MS_A, MS_B), the name server (DNS) sends to the new node (DXT1, DXT_2, DXT_3) the IP address corresponding to the name identifier, the new serving node (DXT_1 , DXT_2, DXT_3) sends information about the subscriber's (MS_A, MS_B) new location to the old serving node 5 (DXT_1, DXT_2, DXT 3) using said IP address, the old serving node (DXT1, DXT2, DXT3) removes the subscriber's (MS_A, MS_B) data from its register, the new one the serving node (DXT1, DXT 2, DXT 3) requests an IP address for said name identifier of the address server (DHCP), the address server (DHCP) allocates a new IP address to the subscriber (MS_A, MS_B) and updates it in the name server ( DNS) if the IP subnet has changed, or the address server (DHCP) retains the subscriber's (MS A, MS B) old address if the IP subnet has not changed, the address server (DHCP) notifies the IP address of the new serving node (DXT_1, DXT_2, DXT_3). Method according to any of claims 1-4, characterized in that the routing of a call from a pairing subscriber (MS A, MS_B) to a pairing subscriber (MS_A, MS_B) comprises steps where the pairing subscriber (MS_A, MS_B) ) selects the paired subscriber (MS_A, MS_B) subscriber identifier, such as a telephone number, a first node (DXT_1, DXT_2, DXT_3) serving the pairing; the subscriber (MS_A, MS_B) derives a name identifier from the selected one; the subscriber identifier; the first node (DXT1, DXT_2, DXT_3) requests the IP address of the paired subscriber (MS_A, MS_B) using said derived name; name server identifier (DNS), the name server (DNS) sends the IP address corresponding to the name identifier to the first node (DXT_1, DXT_2, DXT_3), the first node (DXT_1, DXT_2, DXT_3) directs the call using said IP address of the node serving the paired subscriber (MS_A, MS_B). A method according to any of claims 1-5, characterized by; The resetting of the subscriber's (MS_A, MS_B) calls in the new node (DXT_1, DXT_2, DXT_3) includes steps where the subscriber (MS_A, MS_B) switches the servicing node (DXT_1, DXT_2, DXT_3) and calls the new node (DXT_1, DXT_2, DXT_3) about resetting the call, the new node (DXT_1, DXT_2, DXT_3) controls from the subscriber's (MS_A, MS_B) home directory (CPR) the subscriber's (MS_A, MS_B) right to use the telecommunications network services, the new node (DXT_1, DXT_2, DXT_3) requests the subscriber's (MS__A, MS_B) IP address of the name server (DNS) using the name identifier reserved for the subscriber (MS_A, MS_B), the name server (DNS) sends to the new node the IP address corresponding to the name identifier, the new node (DXT_1, DXT_2, DXT_3) sends information about the subscriber's (MS_A, MS_B) new location, and a call reset request to the old serving node (DXT_1, DXT_2 , DXT_3) using the said IP address, the old server the node (DXT_1, DXT_2, DXT_3) removes the subscriber's data from its register and sends information about the call to the new node (DXT_1, DXT_2, DXT_3), said call information containing a name identifier for the other party in the call, the new node ( DXT1, DXT_2, DXT_3) requests a new IP address for the subscriber's (MS_A, MS_B) named identifier, the address server (DHCP) allocates a new IP address to the subscriber (MS_A, MS_B) and updates it in the name server (DNS) if The IP subnet has • been changed, or the address server (DHCP) maintains the subscriber's (MS A, MS_B) old address if the IP subnet has not been changed; the address server (DHCP) announces the IP address of the new server: the node,: the new node (DXT_1, DXT_2, DXT_3) requests if the other party's IP address on the basis of the other party's name identifier, sends the name server (DNS) to it new node (DXT_1, DXT_2, DXT_3) the IP address corresponding to the other party's name identifier, the new node (DXT1, DXT_2, DXT_3) requests call reset: by the other party's serving node (DXT_1, DXT_2, DXT_3) using of the other party's IP address, the call is redirected via the new node (DXT_1, DXT 2, DXT_3). 35 7. A method according to any of the preceding claims, characterized by an update of subscriber information in the home register 17 112770 (CPR) comprises steps where the subscriber's (MS_A, MS_B) subscriber information is changed in the home register (CPR), the home register (CPR). the name server (DNS) of the IP address corresponding to the subscriber's (MS_A, MS_B) name identifier, the home directory (CPR) transmits, on the basis of said IP address, the changed subscriber information to the node (DXT_1, DXT_2, DXT_3) was the subscriber (MS_A, MS_B). 8. A method according to any of the preceding claims, wherein a -10 signed updated update of the group traffic group's data includes steps where the group traffic group's data is changed in the home directory (HLR), the home directory (HLR) requests from the name server (DNS) about the IP address. corresponds to the name identifier of the group (MS A, MS_B), the home directory (HLR) transmits, on the basis of said IP address, the changed subscriber information to the node (DXT_1, DXT_2, DXT_3) which the server subscriber (MS_A, MS_B). Method according to any one of claims 1-8, characterized in that the name identifier is an MSISDN number, an ITSI number, a short number ISSI and / or the name of a network element or terminal. 10. Telecommunication networks, comprising subscribers (MS_A, MS_B), serving network nodes (DXT1, DXT_2, DXT_3) and at least one home directory (CPR), where subscriber (MS_A, MS B) subscriber data is permanently stored, characterized in that the telecommunications network further : includes a name server (DNS) for controlling subscriber (MS_A, MS_B) location data and for storing at least one name identifier per subscriber (MS_A, MS_B), as well as one assigned to the subscriber (MS_A, MS_B) at each individual time point IP address, so that the serving nodes (DXT_1, DXT 2, DXT_3) can request the subscriber's (MS_A, MS_B) IP address using the at least one name identifier,. an address server (DNCP), which is arranged to allocate an IP address. : to the subscriber (MS_A, MS_B) where the subscriber (MS_A, MS_B) for the first thread registers in any of the serving network nodes (DXT_1, DXT 2, DXT_3) in a new IP subnet and to update the new IP network. the address in the name server (DNS), an IP network, through which messages are transmitted between the name server (DNS), the address server (DHCP) and said serving nodes (DXT_1, DXT_2, DXT_3). Network according to claim 10, characterized by the name identifier being an MSISDN number, an ITSI number, a short number ISSI and / or the name of a network element or a terminal. Network according to claim 10 or 11, characterized in that at least one name identifier is stored in the name server (DNS) for each subscriber created (MS A, MS B). 10 13. According to claim 10, characterized in that said at least one name identifier is stored in the name server (DNS) only when the subscriber (MS_A, MS_B) is registered in the network.