WO2009118046A1

WO2009118046A1 - Service control device and method for establishing a communication connection

Info

Publication number: WO2009118046A1
Application number: PCT/EP2008/053708
Authority: WO
Inventors: Claudio Treschau
Original assignee: Nokia Siemens Networks Oy
Priority date: 2008-03-28
Filing date: 2008-03-28
Publication date: 2009-10-01

Abstract

The invention relates to a method for establishing a communication connection between a first mobile terminal of a calling user and a second mobile terminal of a called user, said method comprising the steps of: a. sending a connection request comprising at least identification data of the calling user and of the called user from the first mobile terminal to a mobile switching centre, b. determining whether the called user has subscribed to a prepaid service, c. detecting whether the called user is roaming in a visited network remote from a home network of the called user, and d. determining whether roaming charges are due for the services of the remote network. In order to enable additional services even if the account of the called user is empty, it is proposed that the method further comprises the steps of: e. detecting if the calling user accepts to take over the roaming charges for the called user, and f. charging the calling user with due roaming charges if the calling user accepts to take over the charges.

Description

SERVICE CONTROL DEVICE AND METHOD FOR ESTABLISHING A COMMUNICATION CONNECTION

1. Field of the Invention

The invention relates to the field of prepaid telecommunica- tion services between mobile terminals, in particular to a method for establishing a communication connection between a first terminal of a calling user and a second terminal of a called user according to the preamble of claim 1 and to a service control device according to the preamble of claim 7.

2. Background of the Invention

In opposite to fixed net telephony, mobile subscribers are charged for incoming calls in the case of roaming and in some countries, especially in Asia and North America also if the called party is in the HPLMN. If for some reason the called party is not in the position to take over such roaming fees, e.g. if a prepaid account of the called user is empty or if the called user simply does not want to pay for being called, such a user will be difficult to reach. The experience shows that many users simply switch off their mobile terminals if they are roaming in foreign countries in order to avoid roaming fees.

Of course, this situation may become bothersome, if e.g. the user has to be urgently reached or if the caller would accept to take over the roaming charges for the callee. In modern telecommunication networks, so called "Intelligent Networks" (IN) are superimposed on a physical network for providing intelligent network components and additional functionalities. Messages generated upon dialling a number asso- ciated to a special intelligent network service are directed to Service Switching Points (SSP) which would then contact a service control point (SCP) associated to the calling user in the intelligent network system.

The service control point evaluates parameters of the call in order to flexibly generate special services tailored to the needs of the user. For mobile telecommunication services, the intelligent networks specifications are standardized by the 3GPP and include e.g. the CAMEL application part CAP or the Siemens Intelligent Network Application Part SINAP, in particular in its extended version SINAP7m+.

3. Summary of the Invention

It is an object of the invention to overcome the above- described difficulties relating to roaming charges, which occur in particular if the called user is a prepaid user.

A further object of the invention is to implement a function for taking over the roaming charges of a called user by means of standard intelligent network's functionalities.

According to a first aspect of the invention, a method for establishing a communication connection between a first terminal of a calling user and a second terminal of a called is proposed. The method comprises the steps of sending a connection request, determining whether the called user is a pre- paid user and detecting whether the called user is roaming and whether roaming charges are due for the services.

The step of sending a connection request includes sending i- dentification data of the calling user and of the called user from the calling mobile terminal to a Mobile Switching Centre (MSC) . The step of determining whether the called user is a prepaid user includes in particular determining whether fees to be paid by the called user are subtracted from a prepaid account of the calling user based on the identification data of the called user. In the above-defined sense, the expression "roaming fees" also covers fees due if the called user is in the HPLMN.

In order to enable the calling of a roaming user even if his prepaid account is empty, it is proposed that the method further comprises the steps of detecting if the calling user accepts to take over the roaming charges for the called user and charging the calling user with due roaming charges if the calling user accepts to take over these charges. Accordingly, the accounting of the service to be established can be managed in an easy and satisfactory way for all participants. The roaming user will be satisfied because he can be reached even if his prepaid account is empty, the calling user will be satisfied because he will be able to reach the called user in urgent situations if only he accepts to take over the roaming charges and the network service provider will be satisfied because additional services may be sold.

According to a preferred embodiment of the invention, the step of determining whether the called user is a prepaid user is executed by using a subscription information request message from a service control point of the calling user to a home location register of the called user. Moreover, it is proposed that the step of detecting if the calling user accepts to take over charges for the called user is performed by evaluating a number dialled by the calling user. In particular, the calling user may dial a certain prefix indicating that he will accept to take over the roaming charges .

It is noted that the takeover of roaming charges may be linked to the condition that the prepaid account of the called user is empty or may be not linked to this condition. Accordingly, the calling user may indicate to take over the roaming charges only if the prepaid account is empty or that he accepts to take over the roaming charges in any case.

Moreover, it is proposed that the step of detecting whether the called user is roaming in a visited network remote from his home network is executed by using a location information request message from a service control point of the calling user to a home location register of the called user.

A double charging of the roaming fees may be avoided if the method further comprises the step of sending information for suppressing the charging of the prepaid account of the called user.

A further aspect of the invention relates to a service control device for use in a communication network implementing the above-described method. The service control device com- prises in particular means for receiving a connection request comprising at least identification data of the calling user and of the called user, wherein the connection request may be transmitted from a first mobile terminal to a mobile switching center communicating with the service control device, means for determining whether the called user is a prepaid user, means for detecting whether the called user is roaming in a visited network remote from a home network of the called user, and means for determining whether roaming charges are due for the services of the remote network.

In order to enable the takeover of roaming charges in a controlled way, it is proposed that the service control device further comprises means for determining whether the calling user is willing to take over the roaming charges and means for charging the calling user at least with the due roaming charges if the calling user is willing to take over the roaming charges.

Moreover, the service control point may comprise means for implementing the above-described advantageous embodiments of the method according to the invention. A description of these means and of the advantages thereof is omitted in order to avoid repetitions. The above description of the advantageous of the method equally applies to embodiments of the service control point implementing this method.

Further characterizing features of the invention will become apparent from the following description of preferred embodi- ments of the invention. The embodiments are specific combinations of characterizing features of the invention and the skilled person will easily find further favourable combinations and sub-combinations of the characterizing features in order to adapt the method and device according to the inven- tion to specific circumstances. The embodiments do not limit the general idea of the invention as defined in the independent claims. 4. Brief Description of the Drawings

Fig. 1 is a schematic representation of a telecommunication network and of a method for establishing a communication con- nection according to the invention.

Fig. 2 is a schematic representation of a telecommunication network and of a method for establishing a communication connection according to a second embodiment of the invention.

5. Detailed Description of the Invention

Fig. 1 is a schematic representation of a method and of a te- lecommunication system for establishing a communication connection between a first mobile terminal A of the calling user and a second mobile terminal B of a called user. The first mobile terminal A is actually supported by a mobile switching centre VMSC-A, which is part of a Home Public Land Mobile Network (HPLMN) . The second mobile terminal B is actually ^λroaming' in the area of the second mobile switching center MSC-VLR, which is part of a Visited Public Land Mobile Network VPLMN. The visited public land mobile network VPLMN is not the home network of the second user and the second user is not subscribed to the VPLMN.

The telecommunication network according to Fig. 1 is an intelligent network (IN) working based on the CAMEL protocol as specified in the third generation partnership project 3GPP. Each of the mobile terminals A, B is associated to a service control point SCP-A, SCP-B managing the intelligent network for functionalities associated to the respective mobile terminal A, B. In the case of Fig. 1, both the first user and the second user are subscribed to prepaid services, wherein fees to be paid by the respective users are subtracted from a prepaid account managed by a prepaid subscription (PPS) service implemented in the respective service control points SCP-A, SCP-B.

In a first step of the method according to the invention, the first mobile terminal A of the calling user generates a mobile originating call (MOC) by dialling a prefix (prefix 1) indicating that the first user is willing to take over the roaming charges for the called user with the second user equipment B. If the mobile switching center VMSC-A receives the MOC-message, the message content including the prefix and the mobile subscriber ISDN number MSISDN-B of the second user is forwarded to the service control point SCP-A associated to the first user. The prefix and the MSISDN-B are forwarded as the called party (CdPa) parameter.

The A-party PPS detects the prefix and determines via a request to the home location register (HLR-B) of the second user whether the called party is also a prepaid service subscriber. This request is performed via Any Time Subscription Information (ATSI) . This assures that only call charges for prepaid service subscribers are taken over. Moreover, the service control point and the PPS service implemented therein determines whether the called user is roaming in a visited network remote from a home network of the called user. This is achieved using an anytime interrogation (ATI) request.

Based on this information, the call charges for both legs (the MOC leg of the calling mobile terminal A and the roaming leg for the called mobile terminal B) will be calculated and charged to the prepaid account of the A-party managed by the A-party PPS service. The PPS service logic implemented in the SCP-A then generates a connect message (CON) by removing the first prefix from the MSISDN-B and by replacing it with a second prefix (prefix 2), putting the resulting combination into the destination rout- ing address field of the connect message and by putting the combination of a further prefix (which may be identical to the first prefix 1 and the mobile subscriber ISDN number MSISDN-A of the calling user into a "generic number" field of the connect message CON.

The content of the generic number field will be taken over into a field for defining an additional calling party and will be displayed on the second mobile terminal B later on. The further prefix may generate a specific display on the called mobile terminal B, the display indicating that the calling user will take over the roaming charges such that the called user may accept the communication connection by knowing that he will not be charged for it.

Based on the second prefix (prefix 2) and the "Destination Routing Address" parameter of the connect message, the service switching point SSP implemented in the VMSC-A executes an action that removes the prefix and requests to suppress the prepaid subscription handling for the mobile terminating call (MTC) -leg from the home location register (HLR) -B associated to the called user. The service switching point uses a "Send Routing Information" (SRI) -message for this purpose including a command for suppressing the automatic billing of the prepaid account of the called user. The SRI-message con- tains a "suppress-T-CSI"-flag.

Finally, the VMSC-A executes the normal call-set up to the called party using the mobile subscriber roaming number (MSRN) received in a sent routing information-response message (SRI-Resp) .

In the above embodiment, the detection whether the calling user accepts to take over the roaming charges is performed by evaluating the first prefix added to the MSISDN-B in the mobile originating call message. The detection whether the called user is ready is achieved using the ATI request to the HLR-B and the determination whether the called user is a pre- paid user is achieved using the ATSI request sent from the SCP-A to the HLR-B. Based on the result, the first user is charged with the due roaming charges in addition to his regular call charges. The suppression of the charging of the prepaid account of the called user is achieved by adding a sec- ond prefix to the MSISDN-B in the connect (CON) message and by including a corresponding parameter in the sent routing information (SRI) -request .

Fig. 2 shows a method and a telecommunication system accord- ing to a further embodiment of the invention, wherein the first user is a postpaid user not subscribed to a prepaid service. In comparison to the embodiment of Fig. 1, the functions performed by the A-party PPS service in the embodiment of Fig. 1 are implemented in a general A-party intelligent network (IN) service in the embodiment of Fig. 2.

As in Fig. 1, the called charges for the terminating leg (e.g. the roaming leg for the called user B) are calculated by the service control point SCP-A associated to the calling user, which uses the any time subscription information (ATSI) request and the anytime information (ATI) request in order to determine the network the roaming user B is camped on. The thus determined call charges are written to the Mobile Originating Call Charging Data Record (MOC CDR) of the postpaid A-party subscriber using a furnish charging information (FCI) message, in particular the free format data parameter thereof. The further processing is identical to the processing described with reference to Fig. 1 and is omitted in order to avoid repetitions.

Another embodiment of the general A-party intelligent network (IN) service associated to the calling user is to write an indication that the calling user is willing to take over the "roaming" charges for the called user as well and further needed information like the location of the called user into the Mobile Originating Call Charging Data Record (MOC CDR) of the post-paid A-party subscriber using a furnish charging information (FCI) message, in particular the free format data parameter thereof. It is than task of the post-processing for the Mobile Originating Call Charging Data Record (MOC CDR) to calculate the correct charges for the calling user and put this on the bill.

The invention may be completely realised by means of a ready existing intelligent network technologies and neither additional network element nor special routines for updating or running this potential network element are necessary. The call success rate and the revenues for the network operator are increasing because additional communication connections are possible.

The end users will be satisfied since the calling party can reach the called user B despite B does not have any money at his account. The B-party will be satisfied because he can get calls even when he has no money at his account if someone really needs to talk to him.

Claims

1. Method for establishing a communication connection between a first mobile terminal of a calling user and a second mobile terminal of a called user, said method comprising the steps of: a. sending a connection request comprising at least identification data of the calling user and of the called user from the first mobile terminal to a mo- bile switching centre, b. determining whether the called user has subscribed to a prepaid service, c. detecting whether the called user is roaming in a visited network remote from a home network of the called user, and d. determining whether roaming charges are due for the services of the remote network, characterized by further comprising the steps of: e. detecting if the calling user accepts to take over the roaming charges for the called user, and f . charging the calling user with due roaming charges if the calling user accepts to take over the charges .

2. Method according to claim 1, wherein the step of determining whether the called user is a prepaid user is executed by sending a subscription information request message from a service control point of the calling user to a home location register of the called user.

3. Method according to one of the preceding claims, wherein said step of detecting if the calling user accepts to take over charges for the called user is performed by evaluating a prefix dialled by the calling user.

4. Method according to one of the preceding claims, wherein the step of detecting whether the called user is roaming in a visited network is executed by sending a location information request message from a service control point of the calling user to a home location register of the called user.

5. Method according to one of the preceding claims, further comprising the step of sending information for suppressing the charging of the prepaid account of the called user .

6. Method according to one of the preceding claims, wherein said step of determining whether the calling user is willing to take over the roaming charges based on subscription data of the calling user is performed in a service control device by evaluating a prefix of a num- ber dialled by the calling user.

7. Service control device for use in a communication network, said service control device comprising: a. means for receiving a connection request comprising at least identification data of a calling user and of a called user from the first mobile terminal to a mobile switching centre, b. means for determining whether the called user has subscribed to a prepaid service, c. means for detecting whether the called user is roaming in a visited network remote from a home network of the called user, and d. means for determining whether roaming charges are due for the services of the remote network, characterized by further comprising: e. means for determining whether the calling user is willing to take over the roaming charges for the called user and f . means for charging the calling user at least with the due roaming charges if the calling user is willing to take said over said roaming charges.

8. Service control device according to claim 7, wherein said means for determining whether the called user is a prepaid user is configured to send a subscription information request to a home location register of the called user .

9. Service control device according to claim 7 or 8, wherein said means for detecting whether the called user is roaming in a visited network is configured to send a location information request to a home location register of the called user.

10. Service control device according to one of claims 7 - 9, wherein said means for determining whether the calling user is willing to take over the roaming charges based on subscription data of the calling user is configured to evaluate a prefix of a number dialled by the calling user .

11. Service control device according to one of claims 7 - 9, wherein said means for charging the calling user least with the due roaming charges is configured to add information for suppressing the charging of the called user and indicating that the calling user takes over the roaming charges to a connect message sent to a mobile switching centre.

12. Service control device according to claim 11, wherein said information for suppressing the charging of the called user is added as a prefix to a routing address of the called user.