WO2003058933A1

WO2003058933A1 - Method and system for call forwarding

Info

Publication number: WO2003058933A1
Application number: PCT/FI2002/000984
Authority: WO
Inventors: Ilkka Veuro; Joni Nisula
Original assignee: Oy Radiolinja Ab
Priority date: 2001-12-20
Filing date: 2002-12-04
Publication date: 2003-07-17
Also published as: AU2002346772A1; FI20012529A0; FI20012529A

Abstract

A call forwarding method and system for several telecommunication network subscriber connections (B1, B2, B3, B4,…, Bn). According to the invention, a call forwarding service is arranged in the telecommunication network by arranging in the call forwarding server (10, 11, 12) a group of subscriber connections (B1, B2, B3, B4,…, Bn), which is composed of, at least, two telecommunication network subscriber connections, and that the call forwarding service is updated by sending the service call number from the subscriber connection of the group of subscriber connections, whereupon the subscriber connection from which the above mentioned call number was sent, is updated to be the shared receiving subscriber connection of the subscriber group.

Description

Method and system for call forwarding

The present invention relates to the accessibility management in telecommunication networks. More specifically, the object of the present invention is the method and system for call forwarding in communication networks.

In this application, a communication network refers to all such analog and/or digital communication and data transmission networks to which the terminal equipment are connected by means of a fixed or wireless connection, i.e. the communication network can be, for example: a fixed telecommunication network i.e. PSTN (Public Switched Telephone Network), including, i.a. CSTN (Circuit Switched Telephone Network) and ISDN (Integrated Services Digital Network); a fixed data transmission network including, i.a. CSPDN (CSPDN, Circuit Switched Public Data Network) networks and PSPDN (PSPDN, Packet Switched Public Data Network) and IP- networks (IP, Internet Protocol), a wireless telecommunication network, preferably a PLMN (Public Land Mobile Network).

The communication network can also be the above-mentioned networks in closed use.

In the following, to make it simple, communication networks are, in general, referred to by the term "telecommunication network" and more specifically by the terms

"fixed telecommunication network", when referring to a telecommunication network to where terminal equipment are connected by wire, and - a "PLMN", when referring to a telecommunication network, to where the terminal equipment are connected over a wireless interface. To control the connection setups i.e. the calls coming to the telecommunication network subscriber connections, the "intelligence" of the telecommunication networks can be increased by providing the telecommunication network with an IN (Intelligent Network), which can be arranged, one or more, in the telecommunication network. To control the connection setup i.e. the calls coming to the telecommunication network subscriber connections, the "intelligence" of the telecommunication network can be increased by using also an information system, which, per se, can be a very simple computer unit, such as a PC.

At present, the telecommunication network connection subscriber activates the call forwarding, regardless of the type of the subscriber connection, typically so that first, a connection-oriented connection is made from the subscriber connection to the call forwarding control unit, such as a server, after which, the control unit is updated by the commands from the subscriber connection, normally being audio frequency signals i.e. DTMF signals (DTMF, Dual Tone Multi- Frequency). The disadvantage and problem of such call forwarding which is based on the connection-oriented connection and the DTMF command is that, sending the DTMF command takes time and is open to mistakes. In consequence of the second subscriber connection number incorrectly given by the DTMF command the object of directing the call to another subscriber number is lost. Sending the DTMF command also has the weakness that, in order to send the DTMF command, a telecommunications link i.e. a connection-oriented connection, which is subject to a charge for the caller, must be created.

To reduce the risk of errors in the long DTMF commands, the Finnish patent 104931 proposes a method and equipment for directing the calls to a control unit, which is a tone server, or to a database connected to it between the previously stored mobile phone and fixed network subscriber connection so that, after the A- number identification, first the right to direct the calls is checked, and then with the DTMF command, given from the subscriber connection to the control unit, the call forwarding to the mobile phone or the removal of the transfer is enabled. Then, the DTMF commands are simply e.g. "1" = call forwarding on, or "2" = call forwarding off, whereupon the risk of error can be substantially reduced. A fundamental weakness of the solution is, however, that the solution is limited to only two network subscriber connections of different types, which are the mobile network subscriber connection and the fixed network subscriber connection, and that the Fl-patent 104931 does not explain a solution for directing the calls to the fixed network subscriber connection, instead of the mobile network.

The primary objective of the present invention is to facilitate the management of the incoming calls to the subscriber connection numbers of the individual subscriber, and to create a new system for activating the call forwarding.

These objectives have been achieved by the above-mentioned call forwarding method and system, whose characteristic features have been specified in the accompanying claims.

It is generally characteristic for the call forwarding method according to the invention that in the call forwarding method, a call forwarding service is arranged in the telecommunication network, by arranging in the call forwarding server a group of subscriber connections, which is composed of at least two telecommunication network subscriber connections, and that the call forwarding service is updated by sending the call number of the call forwarding service from the optional subscriber connection of the group of subscriber connections, so that the subscriber connection of the group of subscriber connections from which the said call number is sent, is updated to be the shared receiving subscriber connection i.e. a call forwarding subscriber connection.

According to its preferred embodiment it is characteristic for the method according to the invention that the call forwarding server is updated by means of a connectionless connection, which is created in the connection setup step, between the subscriber connection of the group of subscriber connections and the call forwarding server, by sending the call number of the call forwarding server from the subscriber connection of the group of subscriber connections i.e. from the activating subscriber connection. Then, based on the caller identifier signaling during the connection setup step, a calling subscriber connection is identified, after which the call forwarding server is updated in order to define the call receiving subscriber connection.

It is generally characteristic for the call forwarding method according to the invention, that the call forwarding system creates in the telecommunication network a call forwarding service for the several pre-selected subscriber connections, that a group of subscriber connections has been stored to the control and memory unit i.e. to the call forwarding server of the call forwarding service, the group consisting of, at least, two telecommunication network subscriber connections, and that the call forwarding server is updated by sending the call number of the call forwarding server from the optional subscriber connection of the group of subscriber connections, so that, the subscriber connection of the group of subscriber connections, i.e. the activating subscriber connection, which sends the above mentioned call number, is updated to be the shared receiving subscriber connection of the group of subscriber connections i.e. the call forwarding subscriber connection.

According to its preferred embodiment, it is characteristic for the system according to the invention that the call forwarding server is updated by using the connectionless connection, which is created between the subscriber connection of the group of subscriber connections and the call forwarding server, by sending the call number of the call forwarding server from the subscriber connection of the group of subscriber connections. Thus, it is preferred that, based on the caller identifier signaled during the connection setup step, a calling subscriber connection is identified, and the call receiving subscriber connection is updated in the call forwarding server. The call identifier is, for example in the CCS (Common Channel Signalling) a CLI-identifier (CLI, Caller Line Identity) of the IAM (Initial Address Message), which, in order to identify the caller, is picked up from the IAM. Depending on the signaling type in the telecommunication network, being for example the CAS and R2-signalings used in the communications networks and the various signalings used in the data transmission networks, the caller identifier can, without the use of the invention suffering, be other than the above mentioned CLI.

According to a prefeπed embodiment of the invention, the call forwarding server is a network element of the telecommunication network, which can, according to the invention, optionally be: a PLMN element, connected to the HLR (HLR, Home Location Register); and/or a fixed telecommunication network's network element, connected to the home exchange i.e. the local switching exchange of the fixed telecommunication network belonging to the group of subscriber connections. The network element is then preferably a computer unit, such as a PC, arranged to be controlling the connection setup i.e. the calls coming to the telecommunication network's subscriber connections.

According to the invention, the call forwarding server can be a network element of the IN connected to the PLMN and/or to the fixed telecommunication network, and connected or being integrated to the IN service control point for controlling the connection setup i.e. the calls coming to the telecommunication network subscriber connections.

According to the invention, the subscriber connections can all be the PLMN subscriber connections or fixed telecommunication network's subscriber connections or both the fixed telecommunication network's subscriber connections and PLMN subscriber connections. To retrieve the shared number of the call receiving subscriber connection during the call forwarding server call routing, a call forwarding number matrix in the form of an indexed x,y-coordinates, in which the subscriber connection number selected by the customer operates as the call forwarding number search index, has been created in the memory unit of the call forwarding server.

To update the number of the shared call receiving subscriber connection, a call forwarding number matrix in the form of an indexed x,y-coordinates, in which the number of the subscriber connection intended to be the shared call receiving subscriber connection operates as the call forwarding number update index, has been created in the memory unit of the call forwarding server.

The advantages of the invention are, for example that, the updating of the call forwarding service according to the invention, is fast and does not require the sending of even one subscriber connection number of the target subscriber connection, that only the sending of the call number of the call forwarding service from the service user's subscriber connection that the user wants to be a shared call receiving subscriber connection, updates and activates the call forwarding service, which routes all subscriber connections of the pre-selected group of subscriber connections, to the subscriber connection in question, where the call number was sent. The call forwarding service according to the invention operates through the connectionless connection, whereby only a simple call number sending updates the call forwarding service.

The invention is explained in the following with a prefeπed embodiment by referring to the accompanying patent drawing, where

FIG.l. shows diagrammatically the general basic principle of the present invention,

FIG.2 illustrates the system according to the first embodiment of the invention, FIG.3 illustrates the system according to the second embodiment of the invention,

FIG.4 illustrates the system according to the third embodiment of the invention, FIG. 5 illustrates a general principle for updating the call forwarding number, FIG.6 illustrates a prefeπed means for storing the subscriber connection numbers in a matrix form to a call forwarding system according to the invention.

To understand the invention, the fixed telecommunication network and the PLMN and the connection setup step in them is explained at first.

The exchange system in the fixed telecommunication network is hierarchic. The individual subscriber connections of the telecommunication network are connected through their connection cables to the terminal exchange, which forms the lowest exchange level managed by the telecommunication operator. The terminal exchanges are connected to the higher-level local switching exchanges. The local switching exchanges in turn are connected to the higher-level transfer exchanges, which form the highest exchange level managed by the telecommunication network operator. To enable the international traffic, the transfer exchanges are connected to the international exchanges. In such fixed telecommunication network, the location of each subscriber connection is always fixed and previously known.

The PLMN, such as for example the GSM- or GPRS- or UMTS-network, is substantially different from the fixed telecommunication network, because there is a wireless interface between the subscriber connections and the PLMN, and because the subscribers can move freely in the whole PLMN service area, comprising of the coverage areas that are covered by the individual base stations of the PLMN-network base station system. An integral part of the operation of the PLMN is an ongoing subscriber location registration function, with which information on the PLMN exchange, on whose service area the subscriber at each time is located, is updated to the PLMN HLR-register. Creating the communication connection from one subscriber connection to another, in the telecommunication network, is called the connection setup step. Following the connection setup is the communication or telecommunication step.

In the following, the term home exchange refers to the lowest exchange level exchange i.e. the terminal exchange of the fixed telecommunication network, to which the subscriber connections are connected through their connection cable, or the PLMN exchange, such as e.g. a GSM-exchange or a GPRS-support node, on whose service area an individual subscriber is at each time located. The analyzing of the call number of the target subscriber connection, related to the connection setup, is performed in the home exchange of the calling subscriber connection, and the caller identity i.e. A-Id, which in e.g. CCS-signaling is an IAM containing, among other things, the target subscriber connection's complete subscriber connection number, and the caller's CLI-identifier, i.e. the calling line identity, is sent from the calling subscriber connection's home exchange.

When the target subscriber connection is a subscriber connection of a fixed telecommunication network, based on the subscriber connection number of the target subscriber connection, the location of the target subscriber connection and the home exchange are known exactly. Then the sending of the call number of the target subscriber connection starts the connection setup to the target subscriber connection. After the caller's home exchange has received the call number of the target subscriber connection, the caller's home exchange will analyze the call number of the target subscriber connection, after which, the caller's home exchange signals the caller's caller identifier to the target subscriber connection's home exchange. The target subscriber connection's home exchange replies to the connection setup signaling by sending a confirmation message after the target subscriber connection is able to receive the call, or an incoming call alerts in the target. When the target subscriber connection is a PLMN subscriber that can move freely in the PLMN service area, the connection setup will have substantially more steps, than when the target subscriber connection is the fixed telecommunication network's subscriber connection. Consequently, before the caller's caller identity can be sent to the target subscriber connection's home exchange, the cuπent location of the target subscriber connection and its home exchange must be defined.

Because the principle of the connection setup is not dependent on the type of the PLMN or the subscriber connection, and because the equivalent network elements and operations can be found in all the PLMNs according to typical standards, the connection setup in PLMNs, represented by a GSM-network, is described for simplicity.

If the calling subscriber connection is a subscriber connection of a fixed telecommunication network, the call number of the target subscriber connection is signaled to the PLMN gateway exchange. If however, the calling subscriber connection is a PLMN subscriber connection, the call number of the target subscriber connection is signaled to the calling subscriber connection's home exchange. After the gateway exchange or the calling subscriber connection's home exchange has received the call number of the target subscriber connection, the target subscriber's call number is analyzed. Since PLMN does not know before hand, where the target subscriber is located at each time, i.e. what is the target subscriber's home exchange (or through which intermediate PLMN the target subscriber can be reached), a routing enquiry is made by using the MAP (Mobile

Application Protocol) to the PLMN's HLR, to which the location register function constantly updates the information from the PLMN exchange, on whose service area the target subscriber is located. In this connection, the HLR makes a routing number enquiry by using the MAP-protocol to the VLR (Visitor Location Register) of the PLMN of the service area in question, and sends the routing number to the gateway exchange or to the calling subscriber's home exchange, which uses the routing number for choosing the route to the target subscriber's home exchange. When the connection setup signaling is in the target subscriber's home exchange, the target subscriber's home exchange will enquire from its VLR, on which service cell group area the target subscriber is at that time located. Finally, the base station system under the target subscriber's home exchange finds the target subscriber from the individual service cell. The target subscriber's home exchange replies to the connection setup message by sending a confirmation message after the target is able to receive a call or an incoming call alerts in the target.

Both in the fixed telecommunication network, and in the PLMN, an ISUP- protocol (ISUP, ISDN User Part) is preferably used for the cormection setup signaling, and MAP-protocol is used for the routing enquiries.

When the intelligence aπanged in the telecommunication network i.e. the IN or a

PC is used for the call routing, information or sign of the fact that the IN or a PC is controlling the connection setup to the target subscriber connection starting from the target subscriber home exchange, where a PC or the IN's SCP (Service Control Point) is connected to, is triggered to the target subscriber's home exchange and/or to the PLMN's HLR. Then the data transmission between the target subscriber's home exchange and the PC or the IN's SCP, is supported by a suitable application protocol i.e. an AP-protocol, which e.g. in the IN's is preferably the IN AP-protocol (Intelligent Network Application Part).

Referring to Figure 1. According to the basic idea of the method according to the invention, a call forwarding service is created in the telecommunication network for the several pre-selected telecommunication network's subscriber connections Bl, B2, B3, B4,..., Bn. Then, a call forwarding server 10, 11, 12 is aπanged in the telecommunication network, and to its memory and/or control unit, the pre- selected telecommunication network group of subscriber connections B are saved, each of which containing at least two different subscriber connections. The subscriber connections can belong to one telecommunication network, to separate telecommunication networks and/or to various telecommunication networks. However, it is prefeπed that, the subscriber connections belonging to one group are managed by a single physical or juridical direction.

The group of the subscriber connections can be created with the help of and/or by e.g. the telecommunication network operator. Then, the telecommunication network operator stores all optional subscriber connection numbers as a group B to the subscriber connection number register, located in the memory and control unit of the call forwarding server 10, 11, 12 implementing the call forwarding service.

When the call forwarding service according to the invention is completely offered by the telecommunication network operator, will the telecommunication network operator also provide the changes/removals/additions of the subscriber connection numbers of the subscriber connection number register of the group B of the subscriber connections, and the turning on/ off of the call forwarding service.

It should be emphasized that, it is not essential for the present invention, how the call forwarding service turning on and/or turning off or, the changing/removing/- adding of subscriber connection numbers are implemented. Thus, it is only noted shortly that, in the call forwarding server, a subscriber connection number register's user interface can be aπanged, that being most preferably a graphic user interface, whereupon the data transfer connection has preferably been aπanged over the IP -network, whereupon the call forwarding service user can easily modify the individual subscriber connection numbers of the group of subscriber connections B, or add individual subscriber connection numbers to the group of subscriber connections B, or remove subscriber connection numbers from the group of subscriber connections B. Instead of, or beside, the graphical user interface it is of course possible to use other solutions in modifying the subscriber connection number register, and a solution that can be mentioned is the SMS sent to the call forwarding service modifying state call number: e.g. "REMOVE abcdef, bcdefg" or "ADD cdefgh", and/or a series of DTMF commands: "2" = remove, "3" = remove the third subscriber connection of the group, or "3" = add, "cdefgh" = subscriber connection number ("abcdef, "bcdefg" and "cdefgh" mean different alphanumeric subscriber connection numbers). In addition to this, it is prefeπed in the case of the call forwarding service, that the service users have a possibility to turn the call forwarding service off and receive calls to all the individual subscriber connections of the group of subscriber connections B, or coπespondingly to turn the call forwarding service on when they so require. Such call forwarding service "off '/"on"- state, which is not essential to the present invention either, can be created with e.g. a specific call forwarding service "off '/"on"- state call number, and when calling to it, the call forwarding service "off '/"on"- state will be automatically activated. Optionally, the call forwarding service "off '/"on"- state can be activated over the data network from the call forwarding server user interface, or by the "OFF'V'ON" SMS from one of the group of subscriber connections subscriber connection, or by giving the DTMF command "0" = "off tai "1" = "on" to the call forwarding service modifying state call number.

Still refeπing to Fig. 1. According to the basic idea of the call forwarding method according to the invention, the call forwarding service is updated by sending the call forwarding service call number from an optional subscriber connection, which belongs to the group of subscriber connections. Then this subscriber connection of the group of subscriber connections from which the above- mentioned call number service was sent is updated as the shared receiving subscriber connection of the group B i.e. a call forwarding subscriber connection.

According to a prefeπed embodiment of the invention, the call forwarding server

10, 11, 12 is updated through a connectionless connection. A connectionless connection is created between the group of subscriber connections B subscriber connection Bl, B2, B3, B4,..., Bn and the call forwarding server 10, 11, 12 by sending the call forwarding server call number, which is performed from an optional subscriber connection of the group of subscriber connections i.e. from the activating subscriber connection of the call forwarding service. The sending of the call number of the call forwarding server starts the connection setup from the subscriber connection to the call forwarding server 10, 11, 12.

Refer to Fig. 5, where a flow chart of the call forwarding method according to the invention is shown. The calling subscriber connection, which belongs to the subscriber group B stored in the call forwarding server 10, 11, 12 memory unit is identified on the basis of the caller identifier, which e.g. is an IAM used in CCS, signaled during the connection setup step. When the connection setup message is an IAM, the identification of the calling subscriber connection is based on the CLI-identifier (CLI, Caller Line Identity) of the IAM. After identifying the calling subscriber connection, the subscriber connection of the group of subscriber connections B coπesponding to the caller identifier is updated as the new call receiving subscriber connection in the call forwarding server 10, 11, 12.

As it is further shown in Fig. 5, the call forwarding service is first activated or created in the telecommunication network for the use of the user. The telecommunication network operator can implement the inclusion of this connection and the desired subscriber connections to the call forwarding service. Optionally, the call forwarding service can be activated with a separate call forwarding server user interface e.g. over the IP-network. Also, to connect the service, an SMS-message, preferably containing the required subscriber connection numbers included in the call forwarding service, is sent to the call forwarding service connection call number. Additionally, the call forwarding service can be activated by the DTMF commands sent to the call forwarding service connection call number.

When the call forwarding service is used in the call forwarding method according to the invention, the caller identification is preferably used by picking up the CLI from the IAM signaled during the connection setup. With the CLI-identifier, it is possible to identify the call forwarding service user, and find out if the calling subscriber connection belongs to the group B of subscriber connections. In addition to this, the calling subscriber connection is, with the CLI-identifier and after the identification, activated as a new shared call receiving subscriber connection i.e. a call forwarding subscriber connection.

After the shared call receiving number i.e. the call forwarding number has been activated, all the subscriber connections belonging to the group of subscriber connections B are in the call forwarding service, and all the calls meant for the individual subscriber connections belonging to the group of subscriber connections B alert in the activated shared call forwarding number.

To activate the new shared call forwarding number and to update it to the call forwarding service, the call forwarding server is thus called with the call forwarding service call number and with a connectionless connection from the optional subscriber connection Bl, B2, B3, B4,...,Bn of the group B of subscriber connections i.e. from the activating subscriber connection of the call forwarding service updating. As a result of this, the call forwarding service updates automatically the new routing information to the telecommunication network, after which, the calls meant for all the individual subscriber connections of the group of subscriber connections are routed to alert only in the new activated shared call forwarding number.

In the following, refeπing to Figs. 2, 3, 4 showing prefeπed embodiments of the call forwarding system according to the invention, creating a call forwarding service in the telecommunication network for the several pre-selected subscriber connections Bl, B2, B3, B4,...,Bn.

In general, in the call forwarding service control and memory unit 10, 11, 12, which is preferably a call forwarding server, is saved the group B of the subscriber connections Bl, B2, B3, B4,...,Bn, which is composed of at least two telecommunication network subscriber connections that can belong to the same telecommunication network, to separate telecommunication networks and/or to different telecommunication networks, and that according to the basic principle of the invention, the call forwarding server is updated by the sending of the call number of the call forwarding server from the optional subscriber connection of the group of subscriber connections so that, the subscriber connection of the group of subscriber connections from where the above mentioned call number selection was sent, becomes the new shared receiving subscriber connection i.e. the call forwarding subscriber connection of the subscriber connection group.

According to the prefeπed embodiment of the invention, the sending of the call number of the call forwarding service starts the connection setup to the call forwarding server 10, 11, 12. Then the call forwarding server is updated through the connectionless connection of the connection setup, created between the subscriber connection Bl, B2, B3, B4,...,Bn of the subscriber connection group B and the call forwarding server 10, 11, 12 by the sending of the call number of the call forwarding server from the subscriber connection of the group of subscriber connections. Then, on the basis of the CLI-identifier (CLI, Caller Line Identity) of the IAM signaled during the connection setup step, the calling subscriber connection can be identified and the call receiving subscriber connection can be updated to the call forwarding server.

According to the prefeπed embodiments of the invention, the call forwarding server 10, 11, 12 is a telecommunication network's network element. It is prefeπed, according to the invention that, the call forwarding server can be adapted freely as a part of one or more telecommunication networks. The call forwarding server can then optionally be: a PLMN network element 10, with a data transmission connection to preferably the PLMN's HLR 4, as it is shown in Figs. 2 and 3, a network element 12 of a fixed telecommunication network, with a data transmission connection to preferably the home exchange 5 of the fixed telecommunication network subscriber connection B4, as shown in Fig. 2; a network element 11 of the IN, which is connected to the PLMN and/or PSTN, and with a data transmission connection to or integrated in the IN's

SCP -point 6, which in its turn has a data transmission connection to, preferably, both the home exchange 5 of the subscriber connection B4 belonging to the fixed telecommunication network group B, and the HLR 4 of the PLMN.

In the embodiment shown in Fig. 2, the call forwarding server is composed of the network element part 10 connected to the HLR of the PLMN, and of a second network element part 12 connected to the home exchange 5 of the subscriber connection B4 in the fixed telecommunication and belonging to the group B. It must be emphasized that the call forwarding server 10, 12 can naturally be also a single unit server, whereupon the call forwarding server is aπanged in a data transmission connection to both the HLR 4 and the home exchange 5. In the example of Fig. 2, the group B of the subscriber connections B2, B3, B4, selected to be in the call forwarding service, is composed of the subscriber connection B4 of the fixed telecommunication network and of the PLMN subscriber connections B2, B3.

In Fig. 2 it is illustrated an implementation where the shared receiving subscriber connection of all the subscriber connections B2, B3, B4 belonging to the group of subscriber connections B, is the receiving subscriber connection B3, and where the calling subscriber connection is the subscriber connection A of the fixed telecommunication network.

When the calling subscriber connection A sends the call number of one of the individual PLMN subscribers B2 or B3 belonging to the group B, following the connection setup the alert occurs only in the call receiving subscriber connection B3 which was updated to be shared. After sending of the call number from the calling subscriber connection A, the IAM message of the connection setup process is signaled first from the calling subscriber connection to the PLMN's gateway exchange 2, which requests the routing number from the HLR 4 to the called subscriber connection. Because the call forwarding server 10, 12 has updated the information that the call has been transfeπed to the receiving subscriber connection updated to be shared, to the HLR, the gateway exchange receives the routing number, as reply to the routing number enquiry, instead of to the called number of the routing number, to the shared call receiving subscriber connection. The IAM is signaled to the home exchange 1 of the shared call receiving subscriber connection on the basis of this routing number information. It must be emphasized that the PLMN subscriber connections B2 and B3 can be located on the service areas of different home exchanges. When the home exchange of the shared call receiving subscriber connection B3 has received the IAM, and when the shared call receiving subscriber cormection is ready to receive the call, the home exchange of the shared receiving subscriber connection sends a confirmation message to the calling subscriber connection, after which the communication between the calling subscriber connection of the telecommunication network or networks and the subscriber connection updated to be the shared call receiving subscriber connection can start.

Fig. 2 illustrates also a call forwarding updating, where the shared call receiving subscriber connection is a subscriber connection B4 of the fixed telecommunication network or a subscriber connection A of the PLMN. When the calling subscriber connection A sends a call number of an individual subscriber connection belonging to the group B, following the connection setup only the shared call receiving subscriber connection B4 alerts.

If the called subscriber connection is a subscriber connection B2 or B3 of the PLMN, the IAM of the connection setup process is signaled first from the calling subscriber connection A to the gateway exchange 2 of the PLMN, when the calling subscriber connection is a subscriber connection of a fixed telecommunication network, or to the mobile phone exchange when the calling subscriber connection is a subscriber connection of a PLMN. The gateway or mobile phone exchange asks for the routing number to the called subscriber connection from the HLR 4. Because the call forwarding server 10, 12 has updated to the HLR 4 the information on the call forwarding to the call receiving subscriber connection B4, updated to be shared, the gateway exchange or the mobile phone exchange will receive a reply from the routing number enquiry HLR, according to which the connection setup will be routed to the home exchange 5 of the shared call receiving subscriber connection B4. When the home exchange of the shared call receiving subscriber connection has received the IAM and is ready to receive the call, the home exchange of the shared call receiving subscriber connection a confirmation message to the calling subscriber connection, after which the communication between the calling subscriber connection A and the shared call receiving subscriber connection B4 can start.

If also the called subscriber connection is a subscriber connection of a fixed telecommunication network, the IAM of the connection setup process is signaled first to the home exchange of the calling subscriber cormection A, which is a fixed telecommunication network exchange or a mobile phone exchange and which signals the IAM to the called subscriber connection home exchange, which is an exchange of the fixed telecommunication network. Because the call forwarding server 10, 12 has updated to the called subscriber connection home exchange the information on the call forwarding to the receiving subscriber connection B4, updated to be shared, the connection setup is directed from the home exchange of the called subscriber connection to the shared home exchange 5 of the call receiving subscriber connection. When the shared home exchange of the call receiving subscriber connection has received the IAM and is ready to receive the call, the home exchange of the shared call receiving subscriber connection a confirmation message to the calling subscriber connection A, after which the communication between the calling subscriber connection and the shared call receiving subscriber connection B4 can start.

In the second embodiment of the invention shown in Fig. 3, the call forwarding server 10 has been aπanged in the PLMN and it has a data transmission connection to the HLR 4 of the gateway exchange 2 of the PLMN. The calling subscriber connection A can, in this embodiment of Fig. 3, be a subscriber connection of the fixed telecommunication network or of the PLMN. The group of subscriber connections B connected to the call forwarding service is composed of the PLMN subscriber connections B 1 , B2.

It should be noted that, although in the embodiment of Fig. 3, all the PLMN subscriber connections Bl and B2 of the group B have been presented to be connected to one home exchange 1, other PLMN mobile phone exchanges can naturally operate as the home exchanges of the subscriber connections of the group, simply because in the PLMN, the subscriber connections can move in the areas of all the PLMN exchange service areas.

If the called subscriber connection is a subscriber connection B2 of the PLMN, the IAM of the connection setup process is signaled first from the calling subscriber connection A to the gateway exchange 2 of the PLMN, when the calling subscriber connection is a subscriber connection of a fixed telecommunication network, or to the mobile phone exchange, when the calling subscriber connection is a subscriber connection of a PLMN. The gateway exchange or the mobile phone exchange asks for the routing number for the called subscriber connection from the HLR 4. Because the call forwarding server 10 has updated to the HLR the information on the call forwarding to the call receiving subscriber connection B3, updated to be shared, the gateway exchange or. the mobile phone exchange will receive a reply from the routing enquiry HLR, according to which the connection setup will be directed to the home exchange 1 of the shared call receiving subscriber connection. When the home exchange of the shared call receiving subscriber connection has received the IAM and is ready to receive the call, the home exchange of the shared call receiving subscriber connection a confirmation message to the calling subscriber connection, after which the communication between the calling subscriber connection A and the shared call receiving subscriber connection B3 can start.

In the third embodiment of the invention in Fig. 4, the routing of the calls and the traffic in the telecommunication network is controlled by the IN, and called the IN-service. In the embodiment of Fig. 4, the IN's SCP -point 6 has a data transmission connection to at least one exchange 5 of the fixed telecommunication network, and being the home exchange of the subscriber connection/s B4 of the fixed telecommunication network belonging to the group B, and to, at least one, mobile phone exchange of the PLMN, being the home exchange of the subscriber connection B2, B3 belonging to the group B. In the embodiment of Fig. 4, the call forwarding server 11 has been integrated or it has the data transmission connection to the IN's SCP-point 6, and both the subscriber connection of the fixed telecommunication network and the PLMN belong to the group B.

When the connection setup is IN-controlled, the routing is based on the call forwarding information received from the SCP-point 6 and the call forwarding server 11. Then the routing number that relates to the subscriber connection B3, updated to be the shared call receiving subscriber connection, can be requested for directly from the HLR 5. This speeds up considerably the connection setup and the signaling of the IAM related to the connection setup, from the calling subscriber connection A home exchange 5 to the home exchange 1 of the call receiving subscriber connection B3 that has been selected to be shared.

It should be noted that although, in the embodiment of Fig. 4, all the PLMN subscriber connections of the group B have been shown to be connected to one home exchange 1, other PLMN mobile phone exchanges can naturally operate as the home exchanges of the subscriber connections of the group B already solely because the subscriber connections in the PLMN can move in all the PLMN exchange service areas.

If the called subscriber connection is a subscriber connection B2 of the PLMN, and B3 has been updated to be the shared call receiving subscriber connection, the

IAM of the connection setup process is signaled first from the calling subscriber connection A to the gateway exchange 2 of the PLMN, when the calling subscriber connection is a subscriber connection of a fixed telecommunication network, or to the mobile phone exchange, when the calling subscriber connection is a subscriber connection of a PLMN. The gateway exchange or the mobile phone makes the routing number enquiry of the called subscriber connection to the HLR 4. Because the call forwarding server 10 has updated to the HLR the information on the call forwarding to the shared call receiving subscriber connection B3, the gateway exchange or the mobile phone exchange will receive a response to the routing number enquiry, according to which the connection setup will be directed to the home exchange 1 of the shared call receiving subscriber connection. When the home exchange of the shared call receiving subscriber cormection has received the IAM and is ready to receive the call, the home exchange of the shared call receiving subscriber connection sends a confirmation message to the calling subscriber connection, after which the communication between the calling subscriber connection A and the shared call receiving subscriber connection B3 can start.

Figure 4 shows also an update, where the subscriber connection B4 of the fixed telecommunication network has been updated to be the shared call receiving subscriber connection. Then the IAM is signaled to the home exchange of the calling fixed telecommunication network subscriber connection, if the calling subscriber connection is a fixed telecommunication network exchange, or to the mobile phone exchange operating as the home exchange of the PLMN subscriber cormection, if the calling subscriber connection is a PLMN subscriber connection. Because the call directing server 11 connected to the IN's SCP-point 6 has updated the information on the shared call receiving subscriber connection B4 to the home exchanges 1 and 5, the connection setup will be directed, according to the call forwarding information, to the home exchange 1 of the shared call receiving subscriber connection. When the home exchange of the shared call receiving subscriber connection has received the IAM and is ready to receive the call, the home exchange of the shared call receiving subscriber connection sends a confirmation message to the calling subscriber connection, after which the communication between the calling subscriber connection A and the shared call receiving subscriber connection B4 can start.

It should also be noted that although, in the embodiment of the Figure 4, the PLMN exchanges B2, B3 of the group of subscriber connections B have been shown to be connected to one home exchange 1, other PLMN exchanges can naturally operate as the home exchanges of these subscriber connections B2, B3, already solely because the subscriber connections in the PLMN can move in the service areas of all the PLMN's exchanges.

Refeπing to Fig. 6, where a memory register of the group of subscriber connections B aπanged in the call forwarding server 10, 11, 12 is shown, the call forwarding service activating subscriber connection Bl, B2, B3, B4...Bn belonging to the group B, is on the y-axis of the matrix, and where the subscriber connections Bl, B2, B3, B4...Bn belonging to the group B are on the x-axis of the matrix. Call forwarding numbers have been listed in columns under each activating subscriber connection in the matrix, after that a connectionless connection is made from the activating subscriber connection to the call forwarding service call number.

To retrieve the shared calls receiving subscriber connection in the call forwarding server call routing situation, it has, according to the invention, been created an indexed call forwarding number matrix in the shape of a x,y-coordinates in the memory unit of the call forwarding server 10, 11, 12, in this, the call number of the subscriber connection Bl, B2, B3...Bn made in the calling subscriber connection operates as a search index. Additionally, according to the invention, to update the shared call receiving subscriber connection number, there has been formed in the memory unit of the call forwarding server 10, 11, 12 an indexed call forwarding number matrix in the shape of an x,y-coordinates, where the activating subscriber connection meant to be the shared call receiver subscriber connection B3 operates as the call forwarding number update index.

The invention has been explained above only as an example with the prefeπed embodiments and implementations. Naturally, this has not been intended to limit the invention to the individual embodiments and implementation. Thus, as it is known by those skilled in the art, and also because also equivalent solutions can be considered, many optional solutions and modifications are possible in the scope of the inventive idea and the scope of protection defined in the accompanying claims.

Claims

1. A call forwarding method for several subscriber connections (Bl, B2, B3, B4,...,Bn) of the telecommunication network, characterized in that, in the call forwarding method, a call forwarding service is aπanged in the telecommunication network by aπanging in the call forwarding server (10, 11, 12) a group (B) of subscriber connections (Bl, B2, B3, B4,..., Bn), which is composed of, at least, two telecommunication network subscriber connections, and that the call forwarding service is updated by sending the call number of the call forwarding service from the optional subscriber connection of the group of subscriber connections so that, the subscriber connection of the group of the subscriber connections from which the above mentioned call number is sent, is updated to be the shared receiving subscriber connection i.e. the call forwarding subscriber connection of the subscriber group.

2. A call forwarding method according to claim 1, characterized in that the call forwarding server (10, 11, 12) is updated by means of a connectionless connection, which is created between a subscriber connection (Bl, B2, B3, B4, ...,Bn) of the group of subscriber connections (B) and the call forwarding server (10, 11, 12) by sending the call forwarding server call number from the subscriber connection of the group of subscriber connections.

3. A call forwarding method according to claim 2, characterized in that, based on the caller identifier signaled in the connection setup step, the calling subscriber connection is identified, after which the call forwarding server is updated to define the call receiving subscriber connection.

4. A call forwarding system for several subscriber connections (Bl, B2, B3, B4,...,Bn) of the telecommunication network characterized in that the call forwarding system creates in the telecommunication network a call forwarding service for several pre-selected subscriber connections (Bl, B2, B3, B4,..., Bn), that in the call forwarding service control and memory unit (10, 11, 12) i.e in the call forwarding server, there has been stored a group of subscriber connections (B), which is composed of, at least two telecommunication network subscriber connections, and that the call forwarding server is updated by sending the call number of the call forwarding server from the optional subscriber connection of the group of subscriber connections (B) so that, the subscriber connection of the group of subscriber connections that sends the above mentioned call number is being updated to be the shared receiving subscriber connection i.e. the call forwarding subscriber connection of the group of subscriber connections.

5. A call forwarding system according to claim 4, characterized in that the call forwarding server (10, 11, 12) is updated by means of a connectionless connection created between a subscriber connection (Bl, B2, B3, B4, ..., Bn) of the group of subscriber connections (B) and the call forwarding server (10,

11, 12) by sending the call number of the call forwarding server from the subscriber connection of the group of subscriber connections.

6. A call forwarding system according to claim 5 characterized in that, based on the caller identifier signaled in the connection setup step, the calling subscriber connection is being identified, and the call receiving subscriber connection is updated in the call forwarding server.

7. A call forwarding system according to claim 6, characterized in that the caller identifier is preferably a CLI which can be picked up from the IAM used in the CCS, or a coπesponding caller identifier unambiguously identifying the calling subscriber connection in the telecommunication network.

8. A call forwarding system according to any one of claims 4 to 7, characterized in that, to direct the connection setup i.e. the calls coming to the telecommunication network subscriber connections, the call forwarding server is optionally a PLMN network element, which is connected to the HLR (4) or a network element (12) of a fixed telecommunication network, which is connected to the home exchange (5) of the fixed telecommunication network belonging to the group of subscriber connections (B).

9. A call forwarding system according to any one of claim 8, characterized in that the network element is a computer unit, such as a PC, which has been aπanged to direct the connection setup i.e. the calls coming to the telecommunication network subscriber connections.

10. A call forwarding system according to any one of claims 4 to 9, characterized in that, to direct the connection setup i.e. the calls coming to the telecommunication network subscriber connections, the call forwarding server is a network element (11) of an IN connected to the fixed telecommunication network and or to PLMN, and which is connected to or integrated in the IN's SCP-point.

11. A call forwarding system according to any one of claims 4 to 10, characterized in that, in the memory unit of the call forwarding server (10,

11, 12) it has been created an indexed call forwarding number matrix in the shape of an x,y-coordinates, where the number of the subscriber connection (Bl, B2, ...Bn) operates as the search index of the call forwarding number selected by the user.

12. A call forwarding system according to any one of claims 4 to 11, characterized in that in the memory unit of the call forwarding server (10, 11, 12) it has been created an indexed call forwarding number matrix in the shape of an x,y-coordinates, where the subscriber connection number meant to be the shared call receiving subscriber connection (B3) operates as the update index of the call forwarding number.

3. A call forwarding system according to any one of claims 4 to 12, characterized in that, the subscriber connections are either all PLMN subscriber connections (Bl, B2, B3) or the subscriber connections (B4) of a fixed telecommunication network or both subscriber connections of a fixed telecommunication network (B4) and PLMN subscriber connections (Bl, B2, B3).