Method and device for determining a signaling address of a mobile services switching center in a cellular communication system

The Invention relates to a method and a device for determining a signaling address of a mobile switching center in a cellular communication system which both circuit switched and packet switched services offering. In particular, concerns the invention combining GPRS (General Packet Radio Service) in GSM (Global Standard for Mobile Communication). Another Embodiment relates to a system, the UMTS (Universal Mobile Telecommunication offers System).

Out the prior art cellular communication systems, the offering both circuit switched and packet switched services, known.

So is in GSM TS 03.60 V6.1.0 GPRS Service Description, Stage 2, Implementation of the packet-switched GPRS in circuit switched GSM described.

in a cellular communication system which both circuit switched as well as offering packet-switched services, the communication is with devices - for example, the location updating or registration in the network - from the Mobile switching centers of the two services, the following called manageable service, adopted. to Location updating registers a terminal with the new mobile switching center the administering service and provides first terminal data. This mobile switching center will then forward the location update at the home location, the other according to the mentioned standards HLR (Home Location Register), is established. The HLR informs the previous mobile switching center of the administering service about the change of location, and delivers the new mobile switching center of the administering Service more terminal data.

After On completion of this procedure contacted the new mobile switching center the administering service the new mobile switching center of the the other service, and informing them of the change of location of the Terminal.

For this Contacting, it is necessary that the transmitting mobile switching center of the administering service to informing the signaling address of a Mobile switching center of the other service known is.

The for determining the signaling address to be informed of are mobile switching center required information using the terminal data recovered. In the prior art determines the managing mobile switching center the signaling address to be informed mobile switching center of location information of the terminal.

A Location information can be, for example, in which location area or which routing area a terminal is located.

On Location area is a spatial Unit comprising a portion of the circuit switched service, the one or more cells containing one or more but base station subsystems supplied by only one mobile switching center becomes. A mobile switching center can have several location areas take care. A routing area is a spatial unit that a includes area of ​​packet switched service, the one or more contains cells of one or more base station subsystems, but only one mobile switching center is supplied. A mobile switching center can have multiple routing areas take care.

The <figref idrefs="S15">1a</figref> and <figref idrefs="S15">1b</figref> illustrate this Related by a section of a structure of a communication network show that an area - divided in the location areas LA1, LA2, LA3, or the routing areas RA1, RA2, RA3, RA4 - supplied. <figref idrefs="S15">1a</figref> provides the structure for a circuit switched service. It provides a mobile switching center MSC1 four base station subsystems BSS 11, BSS12, BSS13, BSS 14. Two the base station subsystems BSS 11 and BSS12 provide the location area LA1, the base station subsystem BSS13 the location area LA2 and the Base station subsystem BSS 14 to location area LA3.

Analogous to provide <figref idrefs="S15">1b</figref> the structure for a packet-switched service. The mobile switching center SGSN supplied four base station subsystems BSS 11, BSS12, BSS13, BSS 14. The base station subsystem BSS 11 provides the routing area RA1, Base station subsystem BSS12 the routing area RA4, base station subsystem BSS13 the routing area RA2 and base station subsystem BSS 14 to Routing area RA3. The base station subsystems BSS 11 to BSS 14 the circuit switched service are identical with those of the packet-switched Service. This base station subsystems of both services shared.

The identified mobile switching center of the administering service from about the location of a terminal the signaling address to be informed of the mobile switching center another service, this is called site-based approach.

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in the Case of the aforementioned, GSM and GPRS services offering cellular Kommunikationssytems, It is prior art that the GPRS service-providing Mobile switching center (hereafter called GPRS service node) accepts the updating of location data of a terminal and these data are transmitted to a, the GSM service-providing, mobile switching center. Further prior art is that a GPRS service node Signaling address of a mobile switching center using of Leitwegebereichinformationen (in the above mentioned standard GSM TS 03.60 V6.1.0 GPRS Service Description, Stage 2, as Routing Area Information designated) by means of a location-based mapping table wins.

<figref idrefs="S16">2</figref> shows simplifies the process of registration of a terminal to for determining the signaling address of a mobile services switching center. A terminal MS sends, via a base station subsystem BSS, one or more messages to a mobile switching center SGSN of the packet switched service. Here is a message AM1 that the location information on terminal MS contains, transparently from the base station subsystem BSS, i.e. unchanged, to Mobile switching center SGSN transmits. The mobile switching center SGSN determined using the Location information to be notified the signaling address of a Mobile switching center of the circuit switched service.

A location-based mapping table provides a Loc2SigAddr Request LM the sought for signaling address in the reply SM. The location information on the terminal MS is included in the request LM.

On Disadvantage of determining a signaling address by means of a location data-based approach is that a change in the allocation of sites inevitably means a change one, for used the identification of signaling addresses, location-based Allocation table conditionally. These changes increase the Administration costs of the communication system.

The German Patent <patcit><text>DE 196 11 947</text></patcit> performs a process to reduce the number of location updates by using virtual location areas, a. However, this does not solve the problem determining a signaling address of a mobile services switching center.

Accordingly, it is The object of the invention to develop a method and an apparatus that the signaling address of a mobile services switching center effectively and economically determined.

This is inventively dissolved by the teaching of claim 1 and the teaching of claim 8th.

The determined in claim 1 described process the signaling address from the information, which means in the transmission path to achieve this terminal be used, a so-called device-based approach. The assignment the signaling address is thus based on data in a change the location areas or routing areas remain unchanged, thus has a device based allocation table updated less frequently be than in a location-based. This fall, both the costs for the the changes mentioned above, as the administrative costs of the association table.

More advantageous embodiments are the claims 2 to 7 and 9 to 12 to remove.

A Embodiment of the invention according to claim 2, wherein the determination of the signaling address in a mobile switching center accomplished is, offers the advantage that a few devices required are.

As advantageous to reduce production costs and the administrative costs a device based allocation table, it turns out according to claim 3 to carry out the assignment by means of identification means, the an uppermost in a system hierarchy means that the used circuit-switched and packet-switched service in common becomes. In this way you can an allocation table with possible build a few elements.

in the following the invention of an exemplary embodiment and with reference of figures, in which explained.

Following Figures show:

<figref idrefs="S15">1a</figref>: Arrangement of a cellular, circuit-switched communication for a specific area divided into the location areas LA1 to LA3,

<figref idrefs="S15">1b</figref>: Arrangement of a cellular, packet-switched communication for the same area divided into routing areas RA1 to RA4,

<figref idrefs="S16">2</figref>: Notification of a terminal until the determination of the signal at the address location-based approach,

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<figref idrefs="S16">3</figref>: Notification of a terminal up to determine the address signal by a mobile switching center the device-based procedures

<figref idrefs="S17">4</figref>: Location update for Routing area and location area,

<figref idrefs="S18">5</figref>: Hierarchy of a communication system having both a circuit-switched and a packet-switched service provides.

at the device-based approach, is at least one of the two Services jointly identified used to achieve the terminal device.

because each shared device clearly exactly a mobile switching center per Service is associated, the signaling address of the mobile switching center from knowledge of the device recordable by means of a device based Allocation table are obtained. This mapping table can There are, for example, in a GPRS service node. To the Assignment table as possible to keep small, it makes sense, means those category to identify the highest in the system hierarchy, from the circuit-switched and packet switched services used together to supply a terminal, is. According to<figref idrefs="S18">5</figref> shall illustrates what is meant by a top in the system hierarchy, jointly by the packet-switched and circuit-switched services used device is to be understood. Here,<figref idrefs="S18">5</figref> a Section of a cellular mobile Kommunikationssytems User, the both circuit switched and packet switched offering services represent. This segment includes a mobile switching center MSC of the circuit switched service and a mobile switching center SGSN of the packet switched service. In addition, several - in their not functionality unspecified - service node Node01, NODE02, NODE11, NODE21, NODE22, NODE31, NODE32 and NODE33 listed. Service node node01 is for example a node of the circuit-switched Service, service node NODE02 a node of the packet switched service. The service node NODE11 to NODE33 be by both services together used, said service node NODE11 the highest in the system hierarchy, jointly by the packet-switched and circuit-switched services is used. This device may be a base station subsystem be or a radio network controller. Among mobile switching centers within the meaning of this application are service nodes of the above-mentioned communication system to understand, who are concerned with switching tasks, and the stored messages they transport data at a location update to adjust.

For the above -mentioned case, the introduction of GPRS in GSM arises at a joint Standortbereichs- and Leitwegebereichsaktualisierung following sequence, as in <figref idrefs="S17">4</figref> shown.

in a first step registers a terminal MS via a base station subsystem BSS to a GPRS service node SGSN with a Leitwegeaktualisierungsanforderung RAUR on. The base station subsystem BSS transmits this Leitwegeaktualisierungsanforderung RAUR over one for they reserved frame relay channel. By using this Channel, the base station subsystem BSS is uniquely identified. After several messages SecFunc be for safety functions between the terminal MS, the GPRS service node SGSN and the HLR exchange. Then determined the GPRS service node SGSN of the information, which base station subsystem is used in the transmission path, the signaling address of a mobile switching center informational. Now initiates the GPRS service node SGSN in to informing mobile switching center MSC / VLR1 location updating with the Standortaktualisierungsanforderrung LAUR. The subsequent steps to up to and including Temporary subscriber identifier rearrangement message TMSIRC are for Invention no longer relevant and are accordingly not described.

at this solution The following devices may be used: A device that is decorated in a GPRS service node, comprising means for allocating a Sinalisierungsadresse a circuit switched mobile services switching center / visitor location register a GSM network to an informative, the one or more devices clearly identified.

The Device identified in offering the GPRS service node SGSN on the basis of the frame relay channel used by the base station subsystem BSS. The data used for determining the signaling address means to a Allocation table or a sorting tree be that identified the Frame relay channel assign the signaling address.

alternative can also use a sorting tree or an allocation table only the Basisstationssubbsystem from the knowledge of the frame relay channel be determined. Subsequently, on the basis of the identified Basisstationssubsytems the signaling address determined. For this purpose, a device used, set up the offering in a GPRS service node is with &lt;?page 5?&gt;Means for allocating the signaling address to the Information, which base station subsystem of both services is shared. These agents can be an allocation table or a sorting tree, which the base station subsystem indentifizierten BSS assign a signaling address.

A Notification of a terminal to be notified to the determination of the signaling address of a Mobile switching center is in <figref idrefs="S16">3</figref> illustrated. A terminal MS sends a Base station subsystem BSS, one or more messages to a Mobile switching center SGSN of a packet switched service. In this case, a message AM1 that information about the terminal MS contains, transmitted from the base station subsystem to the mobile switching center SGSN. The transmitted base station subsystem this information via one for they reserved frame relay channel NSVC. By using this channel the base station subsystem is uniquely identified. The mobile switching center SGSN determined using these ID to be notified the signaling address of a Mobile switching center of the circuit switched service. To it sends the ID in a request to an IM device based Allocation table Inf2SigAddr. The device based allocation table Inf2SigAddr provides the sought for signaling address in a Answer SM.

in one embodiment of the invention for a UMTS communication system Offerer running the process comparable from. In this configuration, a terminal via a report Radio network controller in a mobile switching center at. When transmitting from the radio network controller to the mobile switching center is a signaling channel by the SCCP (Signaling Connection Control Part) protocol, the radio network controller the clearly identified. determined in the mobile switching center an apparatus comprising means for allocating the signaling address to information that clearly one or more devices identified the sought for signaling address. In this embodiment, identifying a radio network controller. The Means for assigning can for example, be an allocation table or a sorting tree, the information of the signaling channel which is used, allocate the signaling address.