Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W8/00—Network data management
  • H04W8/26—Network addressing or numbering for mobility support
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L61/00—Network arrangements, protocols or services for addressing or naming
  • H04L61/45—Network directories; Name-to-address mapping
  • H04L61/4505—Network directories; Name-to-address mapping using standardised directories; using standardised directory access protocols
  • H04L61/4511—Network directories; Name-to-address mapping using standardised directories; using standardised directory access protocols using domain name system [DNS]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L61/00—Network arrangements, protocols or services for addressing or naming
  • H04L61/50—Address allocation
  • H04L61/5007—Internet protocol [IP] addresses
  • H04L61/5014—Internet protocol [IP] addresses using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L61/00—Network arrangements, protocols or services for addressing or naming
  • H04L61/50—Address allocation
  • H04L61/5084—Providing for device mobility
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W60/00—Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W8/00—Network data management
  • H04W8/18—Processing of user or subscriber data, e.g. subscribed services, user preferences or user profiles; Transfer of user or subscriber data
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W80/00—Wireless network protocols or protocol adaptations to wireless operation
  • H04W80/04—Network layer protocols, e.g. mobile IP [Internet Protocol]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/14—Backbone network devices

Definitions

• the invention relates to telecommunications technology, and particularly to mechanisms that support mobility management in telecommunication networks.
• An object of the invention is thus to provide a new mecha- nism for mobility management in telecommunication networks.
• the invention is based on the idea that a telecommunication network is provided with a packet network domain name server and a packet network address server for managing location information on radio subscribers.
• a subscriber registers as a user of a network service, an IP address is reserved for the subscriber from the address server.
• one or more name identifiers have been or are reserved from the domain name server for indicating the subscriber.
• the new IP address is updated on the domain name server, wherefrom other network nodes may now ask for the subscriber's IP address by means of the name identifier(s) reserved for the subscriber.
• the domain name server thus enables the subscriber to be called by means of several names even if the IP address changes when the location of the subscriber changes sufficiently within the network.
• the invention enables a simple way of introducing additional capacity for location information management since no information has to be updated in a centralized subscriber register when a subscriber registers in a network.
• the centralized subscriber register may, however, be used for check- ing whether or not the subscriber is authorized to use the network's services.
• An advantage of the invention is that it enables standard IP protocols and devices to be utilized in the implementation of location management.
• Figure 1 shows storing subscriber information and location information
• Figure 2 shows updating subscriber location information
• Figure 3 shows call control to subscriber B
• Figure 4 shows returning a subscriber's call to a new location register
• Figure 5 shows operator-controlled updating of subscriber information
• Figure 6 shows dispatcher-controlled updating of group information
• TETRA TErrestrial Trunked RAdio
• IP Internet Protocol
• PMR Private Mobile Radios
• PAMR Public Access Mobile Radios
• PLMN Public Land Mobile Networks
• PSTN Public Switched Telephone Networks
• a TETRA system is a digital telecommunication system, which is developed for public safety and security, public trunking operators and utilities and industry.
• a typical TETRA system basic network architecture comprises Digital Exchanges for TETRA (DXT), to which TETRA Base Stations (TBS) are connected.
• the TETRA system can use a decentralised subscriber database structure, i.e. the system may comprise a home location register HLR and/or a Home Database (HDB), which comprises permanent information on a subscriber and/or a group in the subscribers' home network, and a visitor location register VLR and/or a Visitor Database (VDB), which comprises tem- porary information on a subscriber and/or a group visiting a network.
• Each DXT element may be accompanied by a VLR ⁇ /DB element.
• Some exchanges DXT serve as gateway mobile services switching centres or gateways to other telecommunication networks.
• IP protocol is the actual network protocol, which is responsible for routing an IP message including an address from a source to a destination.
• TCP/IP proto- col Transmission Control Protocol/Internet Protocol
• data is transferred as packet- switched data transfer.
• packet-switched data transfer data is divided into packets wherein each packet, in addition to information payload, comprises a source address and a destination address.
• Each packet is routed through a packet-switched network individually on the basis of the address information. This, then, enables data packets relating to the same communication to travel via different routes and by different delays from the source to the destination, depending on the load of the network.
• each DXT unit can be provided with a direct "exit" of its own through an adjacent router in order to forward IP packets from the TETRA network to the Internet, or vice versa.
• a router is herein used to refer to a device and/or software in a telecommunication network node, a host, capa- ble of directing, on the basis of an address, the information to be transferred in the network to another, possibly different network.
• each exchange DXT may constitute its own IP subnetwork that has its own local IP address space, as shown in the example of Figure 1.
• an IP subnetwork may comprise two or more exchanges DXT, which thus share a common local address space.
• An IP packet comprising an IP address that belongs to the local address space of an IP subnetwork will be routed to the particular subnetwork.
• Figure 1 shows storing TETRA system subscriber information and location information according to the invention and the preferred embodiments thereof.
• a subscriber database resides in an HLR.
• the information comprises different numbers and identifiers of a terminal, calling and receiving rights of a subscriber and supplementary services activated for a user.
• the subscriber information in the home location register according to the system of the invention does not contain location in- formation.
• a large network may comprise visitor location registers VLR.
• An exchange and a VLR may also be combined into one network element.
• the mobility management in a telecommunication network comprises, in addition to the above-mentioned elements, an address server DHCP (Dynamic Host Configuration Protocol), which is responsible for allocating IP addresses to subscribers at the exchanges' request. Subscriber location information is updated on the address server DHCP.
• the network may also comprise a DNS (Domain Name Server) to enable a terminal, such as a mobile station MS, to be paged using several names even if the IP address changes as the subscriber's location changes.
• the DNS carries out name-address conversions.
• a domain name server DNS and an address server DHCP may be combined into one element.
• IP network may, for instance, be an operator's intranet, a local area network LAN or even the Internet.
• the transfer of messages associated with the mobility management according to the invention is carried out through an IP network.
• the actual calls may be estab- lished either as circuit-switched calls (e.g. a TETRA call) or as packet-switched calls (e.g. a Voice over Internet Protocol (VoIP) call).
• circuit-switched calls e.g. a TETRA call
• VoIP Voice over Internet Protocol
• an IP address is reserved for the subscriber station from an address server DHCP.
• some identifiers such as an MSISDN (Mobile Station ISDN Number), ITSI (International TETRA Subscriber Identity), abbreviated number and a name, may have been or are reserved from the domain name server DNS for indicating the subscriber.
• the new IP address is updated on the domain name server DNS to enable future identification of the subscriber by means of the identifiers reserved for the sub- scriber, as well as the IP address.
• an identifier or identifiers may be permanently added to the domain name server when the subscriber is being created and/or temporarily in connection with registration, for example. This could be the case when, for example, an identifier can be transmitted from a sender in a message requesting for registration.
• an HLR ele- ment for example, may be asked for an identifier/identifiers when, for instance, the domain name server temporarily stores the identifiers.
• FIG. 2 shows updating subscriber location information.
• the exchange DXT_1 may first check from the sub- scriber's home location register HLR whether or not the subscriber is authorized to use the services of the network.
• the exchange DXT_1 does not, however, give the subscriber location information to the home location register HLR, as is the case in the conventional systems.
• the exchange may establish an IP connection to the old location exchange DXT_2 by means of the subscriber's identifier.
• the domain name server DNS may have been asked for the IP address corresponding with the user's name, and the IP network may route messages to the old exchange DXT_2 on the basis of the old IP address.
• the exchange may use a message for providing the information on the new location.
• the old location exchange DXT_2 may remove the subscriber information from its register and, in step 7, it may or may not send information on the subscriber, such as the groups to which the subscriber belongs, for example, to the new exchange DXT_1.
• the connection to the old location exchange DXT_2 can thus be established entirely by means of the IP network elements, without loading the home location register.
• the location exchange DXT_1 may ask the address server DHCP for a new address for the subscriber MS_1. If the IP subnetwork has changed, the address server DHCP may give the subscriber a new address and update this on the domain name server. The information on the subscriber's previous location exchange DXT_2 may now also be removed. The new VLR information may also be updated in the HLR.
• a new IP address can always be reserved for the subscriber from a location exchange subnetwork, after which the IP network routers are automatically able to deliver the data packets.
• An address can be reserved using the DHCP protocol, which is the Internet standard.
• the address server DHCP based on the DHCP protocol issues the address.
• a necessary number of identifiers are created for the subscriber in the standard Internet domain name server DNS. This element maintains information on the IP addresses corresponding with the names.
• ISSI7000200 An example of a practical identifier is ISSI7000200, which can be created from the selection of a network or a caller when the subscriber registers. Similarly, identifiers can be created in all those manners in which a subscriber has to be accessible in a network, such as MSISDN0405384208, FSSN65977 and TAPIOLA00230. Identifiers can also be created in a home location register in a similar manner. If, for example, one HLR is the home lo- cation register of all ISSI (Individual Short Subscriber Identity) numbers starting with 6 and 7, two names, HLR6 and HLR7, may be reserved for the home location register. In such a case, connections are established from the exchanges and operator/dispatcher systems simply by using the name.
• ISSI Intelligent Short Subscriber Identity
• FIG. 3 shows call control to subscriber B. Since in the case according to Figure 3 subscriber A makes a call to another mobile subscriber, the exchange DXT_1 of subscriber A is able to create an identifier (IP host name) from the number selected by subscriber A.
• IP host name IP host name
• the exchange DXT_1 may start establishing an IP connection to the subscriber, and in step 2, in connection with connection setup, the domain name server may be asked for the IP address corresponding with the identifier of subscriber B.
• the IP network is able to route messages to the location exchange DXT_2 of subscriber B in step 4.
• the messages may be routed via one or more gateway elements, for example.
• the call can be set up to an exchange DXT 3 of subscriber B through a central network.
• the subscribers' rights can be checked e.g. on the basis of the subscriber information copied into a local area register VLR_3.
• a call can thus be established without loading the subscribers' home location registers HLR. Messages are routed to a correct exchange automatically by means of the IP network routers.
• a call from subscriber A to subscriber B can be established either as a circuit- switched call (e.g. a TETRA call) or as a packet-switched call (e.g. a Voice over Internet Protocol (VoIP) call).
• a circuit- switched call e.g. a TETRA call
• VoIP Voice over Internet Protocol
• Figure 4 shows returning a subscriber's call to a new location exchange.
• call return may be requested for in the new location exchange DXT_1.
• the exchange DXT_1 may check from the subscriber's home location register HLR whether or not the subscriber is authorized to use the services of the network.
• the exchange DXT_1 may establish an IP connection to the old location exchange DXT 2 by means of the subscriber's identifier.
• the domain name server DNS may or may not have been asked for the IP address corresponding with the subscriber's name.
• the IP network may route messages to the old location exchange DXT_2 on the basis of the IP ad- dress.
• the exchange DXT_1 may use a message to provide the subscriber's new location and possibly to ask for call return as well.
• the old location exchange DXT_2 may remove the information on the subscriber from its register and, in step 7, possibly send information on the subscriber, such as the groups the subscriber belongs to and information on the ongoing call, such as informa- tion on a second subscriber to the call, to the new exchange DXT_1.
• the location exchange DXT_1 may ask the address server DHCP for a new address for the subscriber. If the IP subnetwork has changed, the address server DHCP may give the subscriber a new address and update the information on the domain name server.
• the exchange DXT_1 may establish an IP con- nection to the location exchange DXT_3 of the other party to the call on the basis of the received IP address.
• the domain name server can be asked for the IP address corresponding with the subscriber's name, and the IP network routes the messages to the old location exchange DXT_2 on the basis of the IP address.
• the call may be connected to the new location exchange DXT_1 through the central network.
• a call can thus be returned without loading the subscribers' home location registers. Messages are routed to a correct exchange automatically by means of the IP network routers. On the other hand, there is no need for tunnelling of the IP packets using e.g. mo- bile IP technology, which loads the IP network, because a new address for the subscriber is requested in the new location exchange, and the other party to the call is informed of this.
• mo- bile IP technology which loads the IP network
• FIG. 5 shows operator-controlled updating of subscriber information.
• the changes in the subscriber information carried out by the opera- tor can be made in the home location register HLR of the subscriber information in step 1.
• the HLR is able to establish an IP connection to the local area register VLR of the subscriber's location exchange by means of the subscriber's identifier.
• the domain name server DNS can be asked for the IP address corresponding with the subscriber's name, and the IP network may route the messages to the location exchange and the local area register VLR on the basis of the IP address.
• the local area register VLR can acknowledge the changes to the home location register HLR in step 5.
• the home location register HLR does not have to convey the information to the local area register VLR. Instead, the subscriber's names can be created on the domain name server DNS.
• FIG. 6 shows dispatcher-controlled updating of group information.
• the dispatcher changes the group information in step 1
• the changes can be carried out directly in the home location register HLR.
• the home location register may establish an IP connection to the local area register VLR of the subscriber's location exchange by means of the subscriber's identifier.
• the domain name server DNS can be asked for the IP address corresponding with the subscriber's name, and the IP network may route the messages to the location exchange on the basis of the IP address.
• the local area register VLR can acknowledge the changes to the home location register HLR in step 5.
• the invention enables IP technology to applied to storing and inquiring location information. In this manner, most of the update load of the centralized subscriber register, i.e. location updates, for example, may be turned into the responsibility of the elements using the IP technology.
• the IP technology has introduced powerful equipment and standardized development and application tools.
• an IP network domain name server DNS and an address server DHCP can be arranged in a cellular radio network in order to manage radio subscribers' location information, as described above.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Databases & Information Systems (AREA)
• Mobile Radio Communication Systems (AREA)
• Data Exchanges In Wide-Area Networks (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2001
  • 2001-03-30 FI FI20010665A patent/FI112770B/fi not_active IP Right Cessation
• 2002
  • 2002-03-27 WO PCT/FI2002/000268 patent/WO2002080491A1/en not_active Application Discontinuation
  • 2002-03-27 EP EP02712971A patent/EP1386468A1/en not_active Withdrawn

Non-Patent Citations (1)

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