JP2002510913A - Connection setup method for an incoming call intended for a subscriber of a communication network, and a service control unit supporting the connection setup - Google Patents

Abstract

(57) [Summary] The connection setup method of the present invention relates to a service controlled by a service control unit (SCP) from a subscriber database (HLR) based on a query (SRI) of a switching device (GMSC) that receives a call. Information (T-CSI) and an identifier (ID) for addressing to a service switching unit (MSSP) that is actually in charge are transmitted, and an initialization message (IDP) having the identifier (ID) is transmitted from the switching device (GMSC) to the service. The request is transmitted to the control unit (SCP) and transmitted from the service control unit (SCP) to transmit the mobility number (MSRN) indicating the location of the subscriber directly to the service switching unit (MSSP). The connection setup is shortened by requesting the mobility number directly via the service control unit, ie by avoiding the usual two-stage interrogation. This provides a significant gain in terms of signaling cost and connection setup time.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a connection setup method for an incoming call directed to a subscriber of a communication network, and a service control unit that supports the connection setup.

The communication network is, for example, configured as a fixed communication network or a mobile communication network (known as the GSM mobile communication network Global System for Mobile Communications), and has mutually networked switching devices. In a mobile communication network, a base station is connected to each switching device, and the base station connects a communication terminal device via an air interface. The communication terminal allows network access for wireless subscribers of the wireless network. The switching device also serves as a transition to another network, for example a data transmission network or a fixed communication network.

[0003] It is also well known from GSM mobile networks that a subscriber database is used as a storage unit, in which individual subscriber data (eg services registered for each subscriber) are stored. Is stored. One of these storage units is embodied as a so-called home register, which generally resides in a fixed, defined place, in which the data on which the registration of the subscriber is based is stored. Have been. Depending on the current location of the mobile subscriber, the storage unit is provided as a so-called visitor register. Depending on the location of the mobile subscriber, the storage unit also changes with respect to the visitor register in which data specific to that subscriber is located.

[0004] In general, additional services for the subscribers of the communication network (fixed communication network or mobile communication network) are supported by the structure of an intelligent network IN having a service control point. The profile of this service control unit and the additional services stored therein, including the information necessary for its realization, are variable depending on the respective communication network. In this case, the service available in the intelligent network is a service switching unit (service switching unit).
At point), the user is prompted to abort normal call processing and activate access to additional services. "The CAMEL feature, proposed revisions to the
stage 1 description ", ETSI / STC / SMG1., 14.03.95., GSM 02.78, Version 0.4.
0, pages 1-14, CAMEL (Customized Application for Mobil network
Enhanced Logic) platforms are known, which allow the support of additional subscriber-specific services for each provider, for example, if this subscriber is abroad. For this purpose, additional services specific to the operator can be used across the network and service boundaries of one communication network. This is because the CAM signaling (CAMEL Application) required for the requested service is required by the service switching unit that facilitates the additional service.
This is the case, for example, in which part information can be processed and signaling information from the home register and signaling information to the home register can be exchanged with service control units for additional services across network boundaries.

[0005] At the time of call connection setup, a two-stage location inquiry (Interrogation) is performed by a switching device in charge of an incoming call. In this case, the exchange first sends a query to the home register in a first step, which triggers a dialog with the service control unit upon entry of the IN / CAMEL subscription for the incoming call of the subscriber. In the second phase, further interrogation of the home register is attempted, which registers the mobility number of the switching equipment actually serving the called wireless subscriber (mobile subscriber roaming number: Mobil).
Subscriber Roaming Number) and transmits it to the switching device in charge of the incoming call.
This implies high signaling costs and long connection setup times in the network, as well as a lack of flexibility in terms of signaling traffic when errors occur and the IN service is not supported by the communication terminal.

[0006] It is an object of the present invention to provide a method and a service control unit which can improve the connection setup for incoming calls.

This object is achieved according to the invention by a method according to the features of claim 1, and by claim 1
The problem is solved by using the service control unit described in the second feature. Advantageous embodiments result from the dependent claims.

In the connection setup method according to the present invention, information on a service controlled by the service control unit and an identifier of the service switching unit actually in charge are transmitted from the subscriber database based on an inquiry of the switching device receiving the call. An initialization message having the identifier is transmitted from the switching device to the service control unit, and a request from the service control unit to transmit the mobility number indicating the location of the subscriber is transmitted directly to the service switching unit. The connection setup is shortened by requesting the mobility number directly via the service control unit, ie by avoiding the usual two-stage interrogation. This provides a significant gain in terms of signaling cost and connection setup time. This results in an optimum interworking between the service control unit and the service switching unit or devices of the communication network, for example, the switching device and / or the communication terminal serving the called subscriber.

According to one embodiment of the invention, the data or parameters in the request are transmitted directly from the data control unit to the service switching unit, and the call connection is controlled simply and flexibly. In a particularly advantageous embodiment of the invention, a direct connection to the switching device and / or the communication terminal serving the subscriber is set up by transmitting the connection indicator from the service switching unit in the request. This allows information transmission and data transmission between the service control unit and the communication terminal device directly without the insertion circuit of another network device or without occupying the signaling capacity in the network. Advantageous applications of direct data transmission are, for example, additional or optional parameters for charging a call during an existing connection or during connection setup are transmitted to the subscriber's mobile station via the service control unit. Is to be done. In general, future parameters or data which are not yet known and are not fully applied today can also be transmitted directly from the service control unit to the mobile station, without using the additional capacity in the mobile radio network.

According to an advantageous embodiment of the invention, the call forwarding registered for the subscriber is disabled by the request itself or by the service indicator transmitted with the request from the service control unit.

In another embodiment of the invention, an error message is sent from the service switching unit to the service control unit. This error message is transmitted to the switching device which is inquiring the identifier of the call transfer destination when registering the call transfer of the subscriber in response to the initialization message. This is a call control (camel service environment Call For
warding is performed prior to coordinated call forwarding (gsm Call Forwarding) in the communication network (eg, switching equipment or subscriber database).
For this, a certain unified process of call transfer using the service control unit is defined. Thus, a clear and defined interworking between the network devices of the mobile radio network and the service units of the intelligent network is obtained.

The subject of the invention is explained in more detail below with reference to the figures.

FIG. 1 shows a block circuit diagram of a communication network. FIGS. 2 to 4 show, in a schematic diagram, a device for implementing the method according to the invention and the flow of messages corresponding to the various cases of connection setup.

FIG. 1 shows a mobile radio network operating according to the GSM standard as a communication network, and the method of the present invention will be described with reference to the mobile radio network. However, the invention is not limited to mobile networks using GSM technology, but is equally applicable to other networks using other access technologies. The communication network KN usually comprises a plurality of switching devices MSC / VLR interconnected. The switching device MSC / VLR establishes a connection to the wireless subscribers A and B via a base station BS wired to the switching device MSC / VLR and an air interface between the base station BS and the mobile station MS. Form. The mobile station MS is a communication terminal device of the subscriber A that initializes a calling MOC (Mobile Originated Call), or an incoming MTC (Mobile Terminated Ca).
ll) is the communication terminal of subscriber B. Another switching device GMSC / VLR
Form a network transition to another network, for example a fixed telecommunications network PSTN.

[0015] Furthermore, the communication network KN comprises a service control unit SCP (which is
CAMEL Phase 1 has a CSE (CAMEL Service Environment) and a service switching unit SSP to support the network structure of an intelligent network. In this case, each service switching unit SS
P together with the switching equipment MSC / VLR and the switching equipment GMSC / VLR form a service switching unit MSSP, which acts at the interface between the communication network KN and the intelligent network. In this connection, each service control unit SCP must be connected to the switching equipment MSC / VLR or GMSC / VLR, or directly to each service switching unit MSSP. This is shown in the block diagram. This can be done via the communication network KN or via another network. 7 to be achieved. In this embodiment, two service control units SCP exist in the communication network KN, and an INAP signaling unit (Intelligent Network Applicat
ion Part) or CAP signaling part (CAMEL Application Part)
It is directly connected to two data exchange units SSP. Information can also be exchanged between devices of the mobile radio network GSM using a MAP signaling unit (Mobile Application Part). According to FIG. 1, the subscriber database HLR is arranged as a home register of the subscribers A, B, ie a separate memory unit in the communication network KN, which is, for example, the switching device MSC / VLR shown.
, GMSC / VLR. Two switching devices MSC / VLR, GMS
The C / VLR has a subscriber database or visitor register VLR,
This visitor register stores the subscriber data of the subscribers A and B which the mobile subscriber holds in the service area of the respective switching equipment.

When an incoming call directed to the wireless subscriber B, for example, an incoming call from the fixed communication network PSTN, reaches the switching device GMSC / VLR of the network transition unit, connection setup is performed based on the incoming mobile subscriber call number MSISDN. Are initialized and processed. On the basis of the interrogation of the switching device GMSC / VLR, the home register HLR stores information on the services (IN services) controlled by the service control unit SCP and the service switching unit MS.
It sends the SP identifier together with the switching equipment MSC / VLR serving the subscriber B. The service control unit SCP which manages the service is preferably selected according to the SCP address entered in the home register. Switching device GM
The SC / VLR forms an initialization message after its reception and sends this together with the identifier to the selected service control unit SCP. The service control unit SCP forms a request to transmit a mobility number MSRN indicating the location of the wireless subscriber. This mobility number is sent directly to the service switching unit MSSP specified by the identifier. The mobility number is transferred via the service control unit SCP (home register HLR).
By making the request directly (without going through) the normal re-interrogation via the switching device GMSC / VLR can be avoided. This provides significant gains in terms of signaling costs and connection setup times for incoming calls using services managed by each service control unit SCP. Service control unit SCP and service switching unit MS
The optimal interworking between the SP or the communication network KN and / or the switching equipment MSC / VLR serving the called subscriber of the communication terminal MS results from the direct request according to the invention. According to the invention, each service control unit SCP, in accordance with the invention, supports a connection set-up, a storage device SP for storing an initialization message and an identifier for addressing of the service switching unit MSSP, and a mobility number for the service switching unit MS.
A control unit SE which forms a direct request for transmission via the switching unit MSC / VLR serving the SP or the subscriber B.

FIG. 2 shows the flow of messages between devices involved in connection setup. Here the exchange device GMSC, home register HLR, memory device S
There is a service control unit SCP with P and a control device SE, a service switching unit MSSP and a communication terminal MS. The subscriber A initializing the call selects the mobile subscriber call number MSISDN of the wireless subscriber B (for example in a fixed network). This call number is received by the switching unit GMSC of the mobile radio network at the network transition (step 1). In response, the switching device GMSC sends an inquiry SRI (Send Routing Info) to the home register HLR (step 2), and this home register sends information T-CSI (CAMEL Subscription Identity) to the wireless subscriber. Is stored. With this information T-CSI, the service control unit SCP becomes IN / CAME.
It is identified to be included in the call connection for management of the L service. The information T-CSI also implicitly defines the service control unit SCP to be branched. Therefore, home register HLR stores information T-CSI and identifier I.
D are sent back to the interrogating exchange GMSC so that they can be identified by the data exchange unit MSSP, ie the exchange responsible for subscriber B (step 3). The switching device GMSC sends the initialization message IDP (Init
ial Detection Point), and this message has an identifier ID for the service control unit SCP in addition to other parameters, for example, a service key (Service Key) (step 4). Here, signaling relating to the CAP protocol or another IN protocol is performed.

The storage device SP of the service control unit SCP stores the incoming message I
The DP is stored including the identifier ID. The control device SE of the service control unit SCP forms a request RRN (Request Roaming Number), whereby the service switching unit MSSP or the switching device in charge is requested to transmit the mobility number MSRN directly from the service control unit SCP ( Step 5). Parameters or data are added to the request RRN by the control device SE. Some of these include the mobile subscriber identifier IMSI, the mobile subscriber call number MSISDN, the reference information CR (Call
Reference), additionally connection indicator DDL (Direct Data Link)
And / or Service Indicator SII (Service Interaction Indicator)
) Is sent directly. The service indicator SII indicates that registered call forwarding (gsm Call Forwarding) for the wireless subscriber B is not performed, for example, in the switching equipment, and the connection indicator DDL indicates that the switching equipment serving the wireless subscriber from the service switching unit MSSP. And / or indicates that a direct connection to the communication terminal MS is set up. Connection indicator D
The DL can also be transmitted, so that the called subscriber (here, subscriber B)
Service switching unit MSSP and service control unit SC
The connection for transmitting information to and from P is maintained until a later time. Instead of transmitting the service indicator SII as a parameter in the request RRN, the request RRN itself can also control the call switching registered implicitly for the subscriber from the data switching unit MSSP.

Furthermore, the service control unit SCP can directly transmit additional data ADD (Additional Data) in the request RRN, for example e-parameters, which calculate the cost of the call at the communication terminal MS. The additional data ADD contains information on the time or event to be reported again from the service switching unit MSSP to the service control unit SCP. Suppression of possible announcements is identified by the parameter SOA (Supression Of Announcement) and is directly requested RR
Triggered by the service control unit SCP in N. By this means, the service control unit SCP additionally provides the subscriber B or the subscriber B
Can be transmitted to the communication terminal device MS. This has not been possible until now, especially up to a point after connection setup or during an existing connection.

The service switching unit MSSP sends the mobility number MSRN, preferably together with the identifier KLI (Keep Linkage), in response to the request RRN. This identifier signals the service control unit SCP which keeps the switching equipment and / or the communication terminal MS serving the wireless subscriber, for example, for the duration of the data transmission (step 6).

When receiving the mobility number MSRN, the service control unit SCP
Forms a message CON (Connect) in some cases, and returns the mobility number MSRN in the message to the inquiring switching device GMSC as a response to the initialization message IDP (step 7). This means that the mobility number MSRN is transmitted from the home register HLR as usual to a separate second query (Interr).
This means that it can be supplied from the service control unit SCP at an earlier point in time for the quickest possible connection setup, instead of being supplied after the ogation.

The switching device GMSC sends a connection setup message IAM (Initial Ad
dress message), and the mobility number MS transmitted this message.
The service is transmitted to the switching device of the service switching unit MSSP in charge of the subscriber B together with the RN (step 8). This further connection setup is performed according to the well-known GSM process, where a wireless call PAG (Paging) is first transmitted to one or more radio cells of the location area via one or more base stations ( Step 9), the message CONA by the communication terminal device MS of the subscriber B
(Connect Ack) is confirmed (step 10). In response, the switching device of the service switching unit MSSP sends a response message ANS (Answer) to the switching device GMS.
C, whereby the establishment of the connection setup is signaled to the called subscriber B (step 11).

FIG. 3 shows a connection setup according to the present invention in a case where the service control unit SCP receives an error message ERR instead of the mobility number MSRN in response to a direct request RRN. Therefore, this means differs from the means of FIG. 2 only in the means from step 6 and steps 1 to 4 of the connection setup proceed as described above. When the error message ERR (Error) is reported, the cause of the error is transmitted parameters such as FNS (Facility Not Supported), AS (Absent Subscriber) or N
Displayed based on MSA (No MSRN Available). The parameter FNS signals that subscriber B is basically reachable, but that the desired service cannot be used. Call forwarding, for example forwarding to the CAMEL / IN announcement service (cseCallForwarding), can be applied in this case. Parameter AS
Indicates that subscriber B is generally unreachable, and the parameter NMSA
Indicates that no free mobility number exists in the service switching unit MSSP.

[0024] Call transfer for the subscriber is supported and the service control unit SC
If the identification and the check according to the information cseCF stored by P are possible (step 7), the control unit SE determines the identifier cseFTN (Forward) of the call transfer destination.
To Number) is formed, and this is included in the message CON and transmitted to the inquiring switching device GMSC as a response to the initialization message IDP. Further connection setup is performed using a new call destination, as is well known. If, as a result of the check, call transfer is not supported for the subscriber, the control unit SE
Forms a trigger message RC and sends it back to the interrogating exchange GMSC in response to the initialization message IDP. The switching device GMSC registers the connection set-up which is not valid and carries out the usual measures, for example triggering a call or a new inquiry at a later point in time. The advantage of requesting the mobility number directly via the service control unit SCP is that if an error message occurs in response and if call transfer cseCF by IN / CAMEL service is supported, this will Before the possible call transfer (gsmCF) provided in the mobile radio network, for example in the switching equipment. As a result, a unified call forwarding process is achieved, which can be registered in the mobile radio network in the network device (gsmCF) as well as in the service control unit (cseCF) in connection with the subscriber.

FIG. 4 shows a connection setup according to the invention similar to FIG.
Here, the mobility number MSRN is received by the service control unit SCP in response to the direct request RRN (see step 6) and transmitted by the message CON to the switching device GMSC (step 7). The difference from the above-described sequence is that the service control unit SCP has another message RRB.
(Request Report BCSM) is transmitted together with the parameter TNR (T-Not-Reachable), and when the unreachability to the subscriber B is identified by the service switching unit MSSP on the visitor side only after the transmission of the mobility number MSRN, the service control is performed. The connection process by the unit SCP is permitted. The switching device GMSC sets the information armTNR based on the received parameter TNR, and prepares in advance so that connection processing via the service control unit SCP becomes possible when the connection setup is negative. The switching device sends a connection setup message IAM together with the assigned mobility number MSRN to the switching device of the service switching unit MSSP in charge of subscriber B (step 9). The service switching unit MSSP or the switching device in charge of the called subscriber (here, subscriber B) receives the information SNR (Subscriber Not R).
failed to reach or connect to this subscriber based on
If a paging response is detected, the additional information stored for the connection sgsmCF (supress gsmCF) and the SOA make it impossible to suppress call forwarding and the corresponding announcement service in the mobile radio network (gsmCF). Is triggered (step 10). Thereafter, the trigger message RC is returned to the switching device GMSC (step 11).

On the basis of the previously adjusted information armTNR, the switching device GMSC does not trigger a connection, but forms a message ERB (Event Report BCSM) having information DPE (Detection Point Encountered) and sends this to the service control unit SCP. Send. Thereby, it is possible to inquire about the support of the call transfer of the cseCF (step 12). If the control device SE in the service control unit SCP reports a positive test result of cseCF (step 14),
An identifier cseFTN (Forward To Number) of the destination of the call transfer is formed, which is queried in the message CON as a response to the message ERB.
Sent to MSC. As a result, even if the recognition of unreachability to the subscriber is delayed, IN
It is guaranteed that the call transfer cseCF by the / CAMEL service is performed before the possible call transfer of the gsmCF. As a result, a uniform process of call transfer is achieved, which can be registered in the mobile radio network (gsmCF) as well as in the service control unit (cseCF) in connection with the subscriber.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of a communication network.

FIG. 2 is a schematic diagram of an apparatus operating in the first embodiment of the method of the present invention.

FIG. 3 is a schematic diagram of an apparatus operating in a second embodiment of the method of the present invention.

FIG. 4 is a schematic diagram of an apparatus operating in a third embodiment of the method of the present invention.

Claims (18)

[Claims] 1. A networked switching device (GMSC, MSC) connectable to a communication terminal (MS) accessible to the subscriber via another device (BS) and / or at least one other A switching device operated via a transition to the existing network (PSTN), at least one subscriber database (HLR) storing data of subscribers registered in the communication network, and at least one service switching unit (HLR). MSSP) and a service control unit (SCP) for managing services, the method for setting up a connection for an incoming call directed to a subscriber of a communication network, comprising the steps of: From the subscriber database (HLR) based on the service control unit (S P) to send information (T-CSI) on the service controlled by the P) and an identifier (ID) for addressing to the service switching unit (MSSP) that is actually in charge, The service control unit (SCP) to send a request to transmit a mobility number (MSRN) indicating the location of the subscriber from the service control unit (SCP) directly to the service switching unit (MSSP). ), A connection setup method for an incoming call. 2. The service switching unit (M) including data or parameters from the service control unit (SCP) in a request (RRN) directly.
The method according to claim 1, wherein the method comprises transmitting to the SSP). 3. A request (R) from the service control unit (SCP).
The method according to claim 1 or 2, wherein the service indicator (SII) is transmitted in the RN) and the call forwarding registered for the subscriber based on the service indicator is not used. 4. A request (R) from the service control unit (SCP).
4. The method according to claim 1, further comprising transmitting additional data (ADD) for calculating a billing of the call to be included in the RN. 5. A request (R) from the service control unit (SCP).
RN) and sends a connection indicator (DDL) to the switching equipment (MSC) and / or a communication terminal (MS) serving the subscriber by the service switching unit (MSSP) based on the connection indicator. 5. The method according to claim 1, wherein a connection is set up. 6. A request (R) from the service control unit (SCP).
RN) to transmit a connection indicator (DDL), and based on the connection indicator, a service switching unit (MSS) serving a called subscriber.
6. The method as claimed in claim 1, wherein a connection for transmitting information between P) and the service control unit (SCP) is maintained until a later point in time. 7. The method according to claim 1, wherein the call transfer registered for the subscriber on the basis of the received request (RRN) is not used by the service switching unit (MSSP).
The described method. 8. The service switching unit (MSSP) transmits a mobility number (MSRN) to a service control unit (SCP), and the service control unit transmits a mobility number (MSRN) to a message (C).
The method according to any of the preceding claims, wherein the message is sent to the interrogating switching device (GMSC) in response to the initialization message (IDP) included in ON). 9. An identifier (KL1) from the service switching unit (MSSP).
) Together with the mobility number (MSRN) and the service control unit (S
To the service control unit (S) according to the mobility number.
Switching equipment (MSC) in which the CP serves the direct connection maintenance to the subscriber
The method according to claim 8, and / or signaling to a communication terminal (MS). 10. The service switching unit (MSSP) sends an error message (ERR) to a service control unit (SCP), and when the service control unit registers a call transfer (cseCF) for a subscriber, the call transfer is performed. 7. The method according to claim 1, wherein the destination identifier (cseFTN) is included in the message and transmitted to the inquiring switching device (GMSC) in response to the initialization message (IDP). 11. An error message (ERR) is transmitted from the service switching unit (MSSP) to a service control unit (SCP), and a trigger message (cseCF) is registered when the service control unit registers a call transfer (cseCF) for a subscriber. The method according to any of the preceding claims, wherein the REL is transmitted to the interrogating switching device (GMSC) in response to the initialization message (IDP). 12. A networked switching device (GMSC, MSC) connectable to a communication terminal device (MS) accessible to the subscriber via another device (BS) and / or at least one other A switching device operated via a transition to a public switched telephone network (PSTN), at least one subscriber database (HLR) storing data of subscribers registered in the communication network, and at least one service switching unit (HLR). An initialization message (IDP) stored in a service control unit (SCP) having a service control unit (SCP) for managing a service and supporting a connection setup for an incoming call directed to a subscriber of a communication network; Storage device (SP) Serial initialization message (IDP) exchange device (GMS for receiving the call
C), has an identifier (ID) addressing the service switching unit (MSSP) that is actually in charge, and has a control unit (SE) forming a request (RRN), the request comprising: A service control unit supporting connection setup for incoming calls, which is transmitted directly to a service switching unit (MSSP) for transmission of a mobility number (MSRN) representing the location of the subscriber. 13. The service switching unit (MSSP) wherein data or parameters are formed by the control unit (SE) and are directly sent as requests (RRN).
13. The service control unit according to claim 12, which is transmitted to: 14. A service indicator (S) by said controller (SE).
Service control unit according to claim 12 or 13, wherein II) is formed and transmitted as a request (RRN) and call forwarding (gsmCF) registered for the subscriber based on the service indicator is not used. 15. Additional data (ADD) for calculating the billing of the call by said controller (SE) is formed in the communication terminal (MS) and requested (RRN).
The service control unit according to any one of claims 12 to 14, transmitted as: 16. The control unit (SE) generates additional data (ADD) indicating a time or an event, and the data is added to a service control unit (S).
CP) to the service switching unit (MSSP) and the request (
A service control unit according to any one of claims 12 to 15, transmitted as RRN). 17. A connection indicator (SE) by the controller (SE).
DDL) is formed and transmitted as a request (RRN), and direct from the service switching unit (MSSP) to the switching device (MSC) and / or the communication terminal (MS) serving the subscriber based on the connection indicator. Service control unit according to any one of claims 12 to 16, wherein the connection is set up. 18. The service switching unit (M) by means of a memory device (SP).
The mobility number (MSRN) transmitted from the SSP is stored and formed by the controller (SE) as a response to the initialization message (IDP) of the switching device (GMSC) inquiring about the message (CON) by the message (CON). C
The service control unit according to any one of claims 12 to 17, wherein a mobility number (MSRN) is transmitted together as (ON).