WO2004054293A1

WO2004054293A1 - Transfer of ussd messages to/from ussd external node

Info

Publication number: WO2004054293A1
Application number: PCT/NL2002/000844
Authority: WO
Inventors: Maartje Margaretha Wortman
Original assignee: Me-Omnicom B.V.
Priority date: 2002-12-09
Filing date: 2002-12-18
Publication date: 2004-06-24
Also published as: AU2002353663A1

Abstract

Method for providing USSD message transmission in a telecommunications system between a first network element (10; 1) and a second network element (1; 10). The first and second network element (10; 1) are forming part of or being connected to an originating telecommunications network (2; 11; 20), respectively a recipient telecommunications network (11; 20; 2). The method comprises the steps of obtaining routing data of the second network element (1; 10) in the recipient telecommunications network (11; 20; 2) using HLR interrogation with MAP&lowbar;SEND&lowbar;ROUTING&lowbar;INFORMATION signalling messages, and forwarding the USSD messages from the first network element (10; 1) to the second network element (1; 10) using the obtained routing data. The communication can be initiated by either an application on an USSD external node or a mobile subscriber device as the first network element (10; 1).

Description

TRANFER OF USSD MESSAGES TO/FROM USSD EXTERNAL NODE

Description

Field of the invention

The present invention relates to a method for providing (direct or indirect) communication in a telecommunications system between a first network element and a second network element, the first network element forming part of or being connected to an originating telecommunications network, and the second network element forming part of or being connected to a recipient telecommunications network, in which the originating and recipient telecommunications network are interconnected networks.

In a further aspect, the present invention relates to a telecommunications system, comprising at least an originating and a recipient telecommunications network, the originating telecommunications network comprising a first network element, the recipient telecommunications network comprising a second network element.

State of the art Such a method and system are known, e.g. in present Global System for Mobile

Communications (GSM) telecommunications networks, in which an application is being executed on a server to provide a service to a subscriber. Modern mobile telecommunications networks, such as the GSM allow the transfer of USSD (Unstructured Supplementary Services Data) messages between an application and a Mobile Station (MS). The transfer can be initiated either by the application or by the MS. The application can be resident either in the first telecommunications network or in an internet protocol (IP) network, which is in communication with the first telecommunications network using an appropriate interface, such as a gateway.

In the present invention, the term 'subscribed to' is to be understood to the fact that a network element, such as a mobile subscriber device or mobile station, has a record in a register of the second telecommunications network, such as the home location register (HLR) in a GSM network. The record comprises data, which is necessary to make a connection with the network element. A mobile station MS is automatically registered at the nearest mobile services switching center MSC, the servicing MSC, which is located either in the home network or in a further visited network. As part of the registration process the HLR holding the subscription record for the concerned mobile station MS, sends a copy of the relevant subscriber data, e.g. including the supplementary services to which this particular user has subscribed, to the MSC currently servicing the mobile station MS. The subscriber data is sent using the Insert Subscriber Data command of the MAP protocol used by the GSM standards.

Some messaging protocols, such as the USSD protocol mentioned above, have a disadvantage that they can only be used in a single telecommunications network. When a network element, such as a mobile subscriber device is subscribed to a telecommunications network different from the telecommunication network with which a further network element, such as an application, is in communication (the originating or servicing telecommunications network), it is not possible to initiate and establish (USSD) message exchange from the application to that mobile subscriber device or vice versa. In present GSM networks this is caused by the fact that the mobile subscriber device, to which the application can send the USSD message, is not registered in the home location register (HLR) of the servicing telecommumcations network. The application can not send an USSD message to a mobile subscriber device subscribed to another mobile telecommunications network as the HLR of the serving telecommunications network has no routing information record for mobile subscriber devices subscribing to other telecommunications networks. For the same reason this is not possible even when a mobile subscriber device is roaming (logged on) into the servicing telecommunications network. The term 'logged on' or 'registered' is understood to mean that the information how to connect to mobile subscriber device is known in the associated telecommunications network. This may be the mobile subscriber device's home network or a visited network (roaming).

Modern mobile telecommunications networks, such as the GSM allow the transfer of USSD messages between an application and a Mobile Station (MS). The procedures for conveying USSD messages between an application and a mobile station MS are described in the GSM03.90 technical specifications. The transfer can be initiated either by the application or by the MS. The messages initiated by the mobile station MS can be delivered either to an application resident within or connected the home network (HPLMN) or resident within or connected to the visited network (VPLMN). The GSM technical standard 02.90 specifies in which way the mobile station has to address the application through an USSD message. An exemplary USSD man-machine interface allows the user to input a string with the following format to be used on the mobile station MS: "*SC*<data>#", wherein SC stands for the service code and the data field is a text string which can contain any number of characters. The aforementioned GSM standard reserves three digits for the service code SC. Service codes in the range 150-199 are referred to as visited public land mobile network (VPLMN) service codes and are intended for invoking applications located in the network where the mobile station is currently logged on (registered) regardless whether this is the home network (HPLMN) of the mobile station MS or it is just a visited network.

Service codes in the range 100-149 are referred to as home public land mobile network(HPLMN) service codes and are intended for invoking applications located in the home network of the MS, where the MS is subscribed to.

This addressing scheme is limiting access for the USSD messages initiated by the mobile station to only applications located into or connected to either the home network or the visited network. It is currently not possible for the mobile station to initiate and submit USSD messages to an application connected to a third network wherewith the mobile station MS has no relation.

Summary of the invention

The present invention seeks to provide a method and a telecommunications network for conveying messages between a mobile subscriber device, particularly USSD messages, and an application resident in e.g. a server of an LP network or a (servicing) mobile telecommunications network such as the GSM network, in which the MS is not subscribed to the servicing mobile telecommunications network. The application servicing mobile telecommunications network is the GSM network where the application resides or to which the application is connected. According to the present invention, a method is provided of the type as defined in the preamble of claim 1, in which the method comprises the steps of obtaining routing data of the second network element in the recipient telecommunications network using a first protocol, forwarding messages from the first network element to the second network element using a second protocol and the routing data, in which the second protocol is different from the first protocol.

In a first aspect of the present invention, the first network element is a server executing an application and the second network element is a mobile subscriber device subscribed to the recipient telecommunications network, and the communication is initiated by the application.

This allows to use the routing data obtained using the first protocol, e.g. according to the MAP protocol sections for SMS or voice calls, which is part of the signaling system #7 (SS#7) protocol suite, to route the messages, e.g. USSD messages, originating from the application to a mobile subscriber device subscribed to and in communication with a different telecommunications network.

The messaging services of the mobile telecommunications system are therefore extended to providing USSD messaging channels for applications connected to the serving (originating) telecommunications network to users subscribing to other (recipient) telecommunications networks.

In a second aspect, the present invention also seeks to provide a solution to the problems arising when a mobile subscriber initiates a communication with an application on a different teleconrmunications network. According to this aspect, the first network element is a mobile subscriber device subscribed to the originating telecommumcations network and the second network element is' a server executing an application, connected into the recipient telecommunications network, and the communication is initiated by the mobile subscriber device. The recipient telecommunications network is in this aspect neither the home network nor the visited network (when the mobile station is roaming) of the mobile station. This allows to use the routing data obtained using the first protocol, e.g. according to the signaling system #7 (SS#7) protocol, to route the message, e.g. USSD message, originating from the mobile station located in an originating network to an application located in or connected to a recipient network which is different than the home network or the network that may be visited by the mobile station MS. These cross-network USSD messaging channels created by this invention enables mobile users to access applications, and hence the services provided by those applications, regardless the mobile telecommunications networks where the applications are located or connected to. This can lead to economies of scale in the wireless services space.

The expanded messaging service can be made available by the application serving telecommunications network to commercial providers. Although above SS#7 and USSD are mentioned in association with GSM, these are meant as examples. The present invention also relates to other signalling and messaging protocols for GSM and other types of telecommunications networks, such as TDMA, CDMA, GPRS and 3G networks.

In a further embodiment, the present method uses the SS#7 signalling protocols, which is are standardised protocols widely used in GSM networks and can therefore easily be integrated into existing mobile telecommunications systems. No proprietary transactions or protocols are used at the interface level between the present method implemented in the originating telecommunications network and the recipient telecommunications network, so as to use the full potential of the standardised capabilities of both originating and recipient telecommunications network and to minimise cost of the realisation and integration of the present method. This in parallel will lead to small cost of operations and maintenance.

Further in the context of the second aspect of this invention: to allow addressing of the recipient network element, the second network element is advantageously assigned a unique identification (such as a MSISDN) in the recipient telecommunications network and the routing data is obtained using the unique identification. Although currently the MSISDNs are of course already assigned to a mobile subscriber devices, it may advantageously also be assigned to the application, to allow initiation of communication by the mobile subscriber device. When the originating network element is a mobile subscriber device wishing to communicate with an application being executed on a recipient telecommunications network, the unique application identification may also comprise a service code in a VPLMN service code range (i.e. 150-199) of a telecommunications network in which the mobile subscriber device is logged on to. This allows the associated telecommunications network to correctly forward the message to the recipient telecommunications network. Advantageously, the message syntax to be used is prescribed or pre-recorded in the mobile subscriber device. In a further embodiment of the present method, the routing data comprises an identification or global title of a mobile services switching center which is part of the recipient telecommunications network and services the second network element, e.g. the mobile subscriber device. The recipientsecond telecommunications network may be the mobile subscriber device's home network, or a visited network. This allows to directly address a message from the application to the mobile services switching center with which the mobile subscriber device is in communication.

In an even further embodiment which is applicable to the method in which the application initiates the communication, the routing data comprises an identification (or global title as used in the SS#7 protocols) of a Home Location Register, which is part of the recipient telecommumcations network and services the second network element, i.e. the mobile subscriber device. By forwarding the message from the application to the HLR of the recipient telecommunications network, the further routing to the mobile subscriber device may be implemented via the HLR in the recipient telecommunications network.

This allows an efficient use of the telecommunications network resources and may e.g. be easily implemented

In certain applications, e.g. relating to transactional or mobile payment services, it is desired to protect the messages sent to the mobile subscriber device. For this, in a further embodiment of the present invention, the communication with the second network element using the second protocol is at least partly encrypted, prior to transmitting the message. The method comprises the further steps of receiving data from the first network element, encrypting at least partially the received data, inserting the encrypted data in a message according to the second protocol, forwarding the message to the second network element, receiving back the message from the second network element after insertion of a special code by the user in the second network element, decrypting the received message, and passing on the decrypted message to the first network element. This provides data integrity, prevents endeavoring and resolves the client non-repudiation issue associated with a transactional service. In a further aspect, the present invention provides a telecommunication system of the type as defined in the preamble of claim 10, in which the telecommunications system further comprises processing means which are arranged to execute the method according to the present method. In case that the communication is initiated by the mobile subscriber device, the processing means may be positioned distributed, i.e. first processing means maybe part of the originating telecommunications network and second processing means may be part of the recipient telecommunications network. This allows efficient allocation of method steps over the relevant telecommunications networks.

The present telecommunications network realised with the integration of the processing means executing the present method within one mobile telecommunications network may interconnect with several other telecommunication networks, (or public land mobile networks), thus opening the messaging channels for applications to an unprecedented wide population of (mobile) subscribers .

The first or second network element form part of the originating or recipient telecommunications network, or may be comprised in a data network, which is interconnected with the originating or recipient telecommunications network.

To allow easy implementation of the encryption and decryption functionality of the present method, the telecommunications system further comprising data encryption/decryption means for at least partially encrypting messages from the processing means.

In an even further aspect, the present invention relates to a computer program product comprising executable code, which when loaded on a processing system connected to a telecommunications network, enables the processing system to execute the method steps as defined according to the present invention.

Short description of drawings

The present invention will now be explained in further detail using a number of exemplary embodiments, with reference to the accompanying drawings, in which Fig. 1 shows a schematic view of a telecommunications network with an application communicating with a mobile subscriber device according to the state of the art;

Fig. 2 shows a schematic view of a telecommunications network with an application communicating with a mobile subscriber device according to a first embodiment of the present invention; Fig. 3 shows a schematic view of a telecommunications network with an application communicating with a mobile subscriber device according to a second embodiment of the present invention;

Fig. 4 shows a schematic view of a telecommunications network with an application communicating with a mobile subscriber device according to a third embodiment of the present invention;

Fig. 5 shows a schematic view of a telecommunications network with a mobile subscriber device initiating communication with an application according to the state of the art; and Fig. 6 shows a schematic view of a telecommunications network with a mobile subscriber device initiating communication with an application according to a first embodiment of a further aspect of the present invention.

Detailed description of embodiments The present invention can be implemented in a number of various aspects.

One (first) aspect relates to the communication between an application and a mobile subscriber device when the communication is initiated by the application. The other (second) aspect relates to the communication between a mobile subscriber device and an application when the communication is initiated by the mobile subscriber device. The two aspects of the method are completely independent of each other, meaning that one will perform without the other. The first aspect is clarified with reference to the Figs. 1 through 4 and the second aspect will be clarified with reference to the Figs. 5 and 6.

In Fig. 1, a schematic view is shown of a telecommunications network system, in which an application 10 communicates with a recipient mobile subscriber device 1. The mobile subscriber device 1 is logged on to a telecommunications network 2, which further comprises a mobile services switching center (MSC) 3, a visitor location register (VLR) 4, and a home location register (HLR) 5.

Modern mobile telecommunications networks 2, such as the Global System for Mobile Communications (GSM), allow the transfer of Unstructured Supplementary Services Data (USSD) messages between the application 10 and the mobile subscriber device 1, hereinafter referred to as Mobile Station (MS). The transfer can be initiated either by the application 10 or by the MS 1. The application 10 can be resident either in a server or processing system in a public land mobile network 2 (PLMN) or in a separate internet protocol (IP) network 7, as depicted in Fig. 1.

The GSM system and other types of telecommunications networks, such as TDMA, CDMA, 3G are well known to the person skilled in the art, as well as the USSD specifications, and the TCP/IP protocol used in the IP network 7, and are therefor not discussed here in detail.

Modern telecommunications networks 2, such as a GSM network, use signalling protocols to transport control data over the elements of the network 2 (MSC 3, VLR 4, HLR 5 and USSD gateway 6). A description of the Signalling System number 7 and the IS-41 protocol is given in The Communications Handbook, CRC Press, Boca Raton 1997 and Signalling System #7 by Travis Russel. McGrawHill Series 1995 and other public specifications from the International Telecommunications Union- Telecommunications Standards Society (ITU-TS).

The protocol layers of the Signalling System # 7 relevant to this invention are briefly described:

1) A Message Transfer Part (MTP) consisting of three layers: MTP Level 1 responsible for signalling data link functions and equivalent of the OSI Model Layer 1, MTP Level 2 responsible for signalling link functions and equivalent of the OSI Model Layer 2, and MTP3 responsible for signalling network functions and equivalent to the lower sub-layer of the OSI Model Layer 3.

2) A Signalling Connection Control Part (SCCP) completing the functions of MTP Level 3 as to provide the full functional equivalent of the OSI Model Layer 3.

3) An Applications Part, consisting of the Transaction Capabilities Application Part (TCAP) which provides services to the Mobile Application Part (MAP) especially created for the GSM System.

The GSM system uses the Signalling System # 7 which has been enhanced by a Mobile Application Part (MAP) which is specified in GSM Technical Specification 09.02 (Mobile Application Part (MAP) specification) or ETSI European Telecommunication Standard ETS 300 599 (February 1995). This invention is applicable for any vendor specific variants of these protocols, such as for example the EMAP from Ericsson.

The USSD message can be network initiated or mobile initiated. For the network initiated scenario, as described with reference to the Figs. 1-4, the initiating application 10 can reside on the MSC 3, VLR 4, or HLR 5. If the application resides on an IP network 7, the network 2 further incorporates an USSD gateway 6. The protocols used between the application 10 and the USSD gateway 6 are e.g. described in SMPP V 5.0, Short Message Peer to Peer protocol, SMSForum, www.smsfoiavm.net. The application 10 needs to open an SMPP session to the USSD gateway 6 as described in the SMPP specifications. Subsequently the message is conveyed to the MS 1 using USSD messages.

The telecommunications network 2 used by the application 10 to convey its USSD messages is named the application servicing network 2 or originating network. This naming applies for both scenario's: when the application 10 resides on the MSC 3, VLR 4 or HLR 5 of the network 2 or when the application 10 connects to the network 2 through an USSD gateway 6.

The USSD message is forwarded by the USSD gateway 6 through an USSD operation to a home location register HLR 5 in the network 2. The USSD operation can be either a request, asking the MS 1 to provide information in its response, or it can be a notification requiring no information in the response from the MS 1. The HLR 5 contains routing information for each MS 1 subscribing to the telecommunications network 2. The routing information stored in the HLR 5 is in the form of a Global Title (GT) of the visitor location register VLR 4. A mobile station MS 1 is automatically registered at the nearest mobile services switching center MSC 3, the servicing MSC, either in the network 2 or in a further network (to be discussed below). The GT (global title) of the serving MSC 3 is registered in the VLR 4 of the serving network 2. If the MS 1 is registered in the network 2 the routing information stored in the HLR 5 for that specific MS 1 is the GT of the VLR 4 in the network 2. If the MS 1 is registered in a further network (e.g. a visited network, not shown) the routing information stored in the HLR 5 for that specific MS 1 is the GT of the VLR 4 in the further network.

When the HLR 5 receives the USSD message from the USSD gateway 6 (or from an application 10 residing on the HLR 5), it retrieves from its own database the routing information for the recipient MS 1 to which the USSD message should be delivered to. The routing information indicates on which VLR 4 the specific MS 1 is registered.

Subsequently the HLR 5 forwards the USSD message (request or notification) to the respective VLR 4, which can be in the network 2 or in a further network. When the VLR 4 receives the USSD message from the HLR 5, it retrieves from its own database the routing information for the recipient MS 1. The routing information indicates on which MSC 3 the specific MS 1 is registered in that network. Subsequently the VLR 4 forwards the USSD message (request or notification) to the respective MSC 3, which at its turn delivers the USSD message to the recipient MS 1. It is important to note that the MS 1, to which the application can send the USSD message, must subscribe to the servicing network 2, i.e. the network 2 to which the application 10 is connected, and more particularly must be registered in the HLR 5 of the servicing network 2. The application 10 can not send an USSD message to an MS 1 subscribed to another mobile telecommunications network, as the HLR 5 of the application servicing network 2, the network used by the application 10 for sending the USSD messages, has no routing information record for mobile stations MS 1 subscribed to other networks. For the same reason this is not possible even when a foreign MS 1 (MS 1 which is a subscriber of another network than the servicing network 2) is roaming into the servicing network 2.

According to a first aspect of the present invention, this problem is solved using a foreign subscriber USSD message server 12 (FSUMS). This FSUMS 12 is implemented as part of the servicing or originating network 2, as depicted in the schematic views of Fig. 2 to Fig. 4. In Figs. 2-4, different networks are involved, which are indicated by different reference signs. Although the different networks comprise the same functional units MSC, VLR, HLR, different reference signs are used to indicate to what kind of network the specific unit belongs.

Fig. 2 shows the telecommunications network, in which the first or application servicing network 2 comprises the message server FSUMS 12. The telecommumcations network is capable of conveying messages submitted by an application 10 resident either on an IP network 7 (as shown in Figs. 2-4) or, alternatively, on the same server on which the FSUMS 12 is resident, to recipient MS's 1 subscribing to a further or recipient network 11, and potentially visiting network 20. The further network 11, 20 is interconnected with the servicing network 2 using signalling transfer points (STP) 9, which are known as such to the person skilled in the art. The recipient MS 1 may be registered (logged on) either in its respective home network 11 (to which the recipient MS 1 has subscribed, embodiment of Figs. 2 and 3) or may be roaming in the servicing network 2 or in another network 20 (Fig. 4) which is interconnected with the servicing network 2 using STP's 9. hi each case the application will be able to submit the message, particularly the USSD message to the recipient MS 1.

When the FSUMS 12 receives the message from the application 10, either through the short message peer to peer (SMPP) protocol when the application 10 resides on an IP network 7, or through an internal communication facility when the application 10 resides on the FSUMS 12, it converts the message to an USSD operation. The conversion is carried out by a USSD gateway which is part of the FSUMS 12. The USSD operation can be an USSD request or an USSD notification, depending whether the application expects some information back from the recipient MS 1. The recipient MS 1 is referred to through its identification number (e.g., a Mobile Station International ISDN Number (MSISDN) and a corresponding International Mobile Station Identity (LMSI).

The FSUMS 12 comprises a Gateway MSC entity. The Gateway MSC entity on FSUMS 12 carries out one of the elements of this invention: it submits a MAP-layer query command to the network 2 about the recipient MS 1. The used command can be either MAP-SEND-ROUTING-INFO-FOR-SM service request (used for short messages) or MAP-SEND-ROUTΓNG-INFORMATION service request (used for calls). The MAP query contains the MSISDN of the recipient MS. The signalling system #7 network will convey the query to a signalling transfer point (STP) 9 where the Global Title translation will take place according to the rules established in the respective STP 9. The STP 9 may potentially interrogate a Mobile Number Portability Signalling Relay Function (MNP_SRF) entity if number portability is supported in the respective network 11, 20. After resolving the GT, the STP 9 will forward the MAP query to the HLR 15 of the concerned network 11 where the recipient MS 1 is subscribed to. The exact routing of the MAP query command from the FSUMS 12 to the HLR 15 of the network 11 where the recipient MS 1 is subscribed to is subject of the Global Title translation methods and procedures as used by the networks 2 and 11. The queried HLR 15 will respond to the MAP query command with MAP- SEND-ROUTING-INFO-FOR-SM service response (used for short messages) respectively MAP-SEND-ROUTING-INFORMATION service response (used for calls). Either response contains the GT of the responding HLR 15 from the network 11 where the recipient MS 1 is subscribed to and the GT of the MSC 13, 23 on which the recipient MS 1 has last time registered (logged on), which is the servicing MSC 13, 23. It additionally contains the LMSI of the recipient MS 1.

The FSUMS 12 retrieves the GT of the responding HLR 15 and the GT of the servicing MSC 13, 23 from the MAP service response. The present method provides two alternatives, both of them being supported and implemented by the FSUMS 12.

The first alternative, as depicted in Fig. 2, consists of inserting the GT of the HLR 15 from the subscription network 11, i.e. the network 11 where the recipient MS 1 is subscribing to, into the USSD request or the USSD notification. Subsequently the FSUMS 12 forwards the USSD message through the corresponding MAP command MAP_UNSTRUCTURED_SS_REQUEST or MAP_UNSTRUCTURED_SS_NOTIFY to the HLR 15 in the subscribing network 11 of the recipient MS 1. In the subscribing network 11 the USSD message is treated according to the normal procedures explained earlier with reference to Fig. 1, until in reaches the recipient MS.

The second alternative, as depicted in Fig. 3 and 4, consists of inserting the GT of the servicing MSC 13, 23, obtained from the MAP service response, into the USSD request or the USSD notification. The servicing MSC 13, 23 can be in the subscribing network 11 of the recipient MS 1 (Fig. 3) or it can be in a visited network 20 (Fig. 4). Subsequently, the FSUMS 12 forwards the USSD message through the corresponding MAP command MAP_UNSTRUCTURED_SS_REQUEST or MAP_UNSTRUCTURED_SS_NOTΓFY to the servicing MSC 13, 23 either in the network 11 (Fig. 3) or when roaming in the network 20 where the recipient MS is registered (Fig. 4).

The second alternative is much more efficient from a resource and performance point of view, however there may be scenario's in which the first alternative has to be used due to several legacy reasons.

In the following, a further aspect of the present invention will be explained in more detail, referring to communication between a mobile subscriber device 1 (or Mobile Station MS) and an application, in which the communication is initiated by the MS 1. Where applicable, elements having the same functionality as in the Figs. 1-4 as described above, are shown with the same reference numeral in Figs. 5 and 6. Here, the originating network is the network to which the MS 1 is logged on: this can be a roaming network 20 or the home network to which the MS 1 is subscribed to (Home PLMN 11). Fig. 5 shows a schematic diagram of a known implementation in which USSD messages are used to start a communication session between the MS 1 and the application 10. The handling of the USSD operation initiated by the mobile station MS 1 to conventional GSM systems is illustrated. The user enters a service code and text string using a keypad (not shown) on the mobile station MS 1. A USSD Handler which is part of the MS 1 analyzes the service code to determine whether the USSD Handler recognizes the service code SC. If the service code is not recognized (which is the case for service codes between 100 and 199 allocated to USSD applications) then the USSD message containing the service code SC and text string is sent from the MS 1 to the MSC/VLR 23 in the PLMN 20 where the MS is logged on (in the case of Fig. 5, this is a network 20, in which the MS 1 is roaming). Note that although the MSC and the VLR are described herein as one entity or single node 23, one skilled in the art will recognize that the MSC and the VLR can be implemented as separate nodes in the mobile telecommunications network 20. The MSC/VLR 23 uses its implemented USSD Handler to determine whether the service code is recognized, i.e. whether the service code is in the range 150-199. If the service code is one of the HPLMN 11 service codes (100-149), which means that the MSC/VLR 23 cannot interpret or process locally the USSD message, the MSC/VLR 23 will forward the message to the HLR 15 in the home PLMN 11 where the MS 1 is subscribed. The USSD handler which is part of the HLR 15 in the home mobile telecommunication network 11 may be capable of routing further the USSD message towards the recipient application 10 only for those applications located in or connected to the same PLMN 11 wherein the HLR 15 is operating.

It is not possible to forward the USSD message directly from the servicing MSC/VLR 23 to the recipient application 10: the USSD message has to be firstly passed to the subscriber's HLR 15, which increases capacity demands on the specific HLR 15. It is also not possible to route the USSD message from the subscriber's HLR 15 to the recipient application 10 when the recipient application 10 is not located into nor connected to the subscriber's home PLMN 11 as the HLR 15 neither has nor it can obtain routing information as how to route the USSD message towards such an application 10.

When the USSD handler on the MSC/VLR 23 recognizes the service code as being a VPLMN service code (150-199) it shall process the request locally according to the aforementioned GSM 03.90 specifications and in this case the processing may include:

- Setting up or releasing signaling and /or speech channels;

- Passing the USSD request to another network entity (unchanged or changed); - Passing a different USSD request to another network entity;

- Requesting further information from the MS 1.

In this scenario the MSC/VLR 23 will forward the USSD message directly to an application which must be connected to or co-located within the same network 20 with the MSC/VLR 23. In any other case the MSC/VLR 23 will have to reject the USSD message submitted by the mobile station MS 1.

According to an embodiment of the present invention these problems are solved using a foreign application USSD message server (FAUMS) 30, 31. A schematic diagram of this embodiment is shown in Fig. 6. This FAUMS 30, 31 has two parts: a first part 30 being implemented in the mobile station MS servicing mobile telecommumcations network or originating network (which can be the home PLMN 11 or a further PLMN 20 to which the MS 1 is logged on), and a second part 31 being implemented in the application servicing mobile telecommunications network 2, the recipient network. The MS servicing PLMN 11 (as shown in Fig. 6 this is the home network to which the MS 1 is subscribed, but this network could also be a network 20, in which the MS 1 is roaming) is the PLMN wherein the MS 1 is currently logged on, while the application servicing PLMN 2 is the PLMN wherein the application 10 is located or is connected to. The FAUMS server 30, 31 provides therefore a direct path for USSD messages initiated by an MS 1 in the originating network 11, 20 to an application 10 located into or connected to the recipient network 2 with no regard to whether the recipient network 2 is or is not the subscribing network 11 of the submitting mobile station 1.

Figure 6 shows the telecommumcations system comprising a mobile station MS servicing mobile telecommunications (second) network 11 (in relation to the embodiment of Fig. 6 the originating network) and an application servicing mobile telecommunications (first) network 2 (in relation to the embodiment of Fig. 6 the recipient network). The second network 11 is comprising the first part 30 of the message server FAUMS, while the first network 2 is comprising the second part 31 of the message server FAUMS. As an element of the invention the application 10 located within or connected to the first network 2, which is the final recipient for the USSD message submitted by the MS 1, is assigned one or more Mobile Station International ISDN Number(s) (MSISDN) (and corresponding International Mobile Station Identity (ies)(LMSI)) as a recipient number for the USSD message. The MSISDN(s) are belonging to the numbering plan of the first network 2 and will be called USSD application mobile number(s) in the following. The assignment is stored in the database of a standard home location register HLR 32 embedded in the second part 31 of the message server FAUMS. As another element of this invention, the HLR 32 embedded in the second part 31 of the FAUMS server is responding to any query addressed to the first network 2 and concerning one of the MSISDN numbers associated with the recipient application 10, i.e. one of the USSD application mobile numbers. The queries maybe addressed through the MAP commands currently supported in the GSM networks, as for example the MAP-SEND-ROUTΓNG-LNFO-SM request service (used for SMS) or MAP- SEND-ROUTΓNG-Γ FORMATION request service (used for calls). The standard HLR 32 embedded in the second part 31 of the message server FAUMS will positively respond to such a query.

As an additional element of the invention, in the query response the HLR 32 embedded in the second part 31 of the message server FAUMS is providing routing information, in the format of an ID or global title, about a standard mobile services switching center MSC/visitor location register VLR 33 also embedded in the second part 31 of the messaging server FAUMS and servicing the MSISDN(s) associated with the recipient application 10, e.g. the USSD mobile application numbers. Herewith the queried MSISDN is seen by a querying foreign network (e.g. network 11 in Fig. 6) as being logged on and being served by the MSC/VLR 33 embedded in the second part 31 of the message server FAUMS. Hence the application 10 to which the respective MSISDN has been assigned is being advertised as logged on or on-line and any message addressed to this application by any interconnected mobile telecommunications network (11, 20) will be collected by the MSC/VLR entities 33 embedded in the second part 31 of the message server FAUMS. Herewith the application can be reached by any USSD message submitted by any subscriber of any interconnected mobile telecommunication network in the wireless space. This is an unsurpassed achievement that enables economies of scales for application providers. Both the HLR 32 and the MSC/VLR 33 embedded in the second part 31 of the messaging server FAUMS are standard GSM network entities and therefore are accessible by means of signaling system (SS#7) from all other entities of the interconnected mobile telecommunications networks. According to this invention the MSC/VLR 13 in the second network 11 forwards the USSD message received from the MS 1 unchanged to the first part 30 of the message server FAUMS, which is a network entity of this second network 11. This is in full alignment with the second scenario described in the aforementioned standard, the GSM03.90 technical specifications. The first part 30 of the message server FAUMS has an embedded gateway function Gateway MSC (GMSC) 34, which is another standard GSM function. When the first part 30 of the message server FAUMS receives the USSD message from the MSC/VLR 13, it parses the routing data in the text field, which enables routing the USSD messages towards the recipient application. It is another element of this invention that the first part of the text field of the

USSD message contains the USSD application mobile number (MSISDN), which is the MSISDN assigned in the first network 2 to the recipient application 10. The USSD message entered by the end-user on the mobile station 1 has therefore the following syntax: *SC*<MSISDN><additional data>#". After the parsing operation has been completed the standard GMSC entity 34 embedded in the first part 30 of the FAUMS server submits a MAP layer command MAP-SEND-ROUTrNG-LNFO-SM service request (used for short messages) or MAP-SEND-ROUTLNG-INFORMATION service request (used for calls) to the second network 2. This command contains the MSISDN inventively retrieved by the first part 30 of the message server FAUMS from the text field of the USSD message. The MAP command is routed from the second network 11 to the standard HLR 32 embedded in the second part 31 of the messaging server FAUMS integrated in the first network 2. The routing procedure is based on standard signaling procedures and global title translation procedures used in the GSM system and the SS#7 signaling system. The standard HLR 32 embedded in the second part 31 of the message server FAUMS responds with an MAP-SEND-ROUTIN-INFO-SM service response respectively MAP-SEND-ROUTING-INFORMATION service response, containing potentially the LMSI associated with the application 10, as well as the routing data,(ID or global title) of the standard MSC/VLR 33 embedded in the second part 31 of the messaging server FAUMS .

Subsequently the first part 30 of the message server FAUMS forwards the USSD message directly to the second part 31 of the message server FAUMS, particularly to the standard MSC/VLR entity 33 embedded in the second part 31 of the message server FAUMS using a corresponding MAP command,

MAP_UNSTRUCTURED_SS_REQUEST or MAP_UNSTRUCTURED_SS_NOTTFY MAP depending of the nature of the USSD message submitted by the MS 1. The MSC/VLR entity 33 in the second part 31 of FAUMS forwards the USSD message internally to a USSD gateway 35 embedded in the second part 31 of the message server FAUMS. The USSD gateway 35 maps the USSD mobile application number, the MSISDN number contained in the incoming USSD message, to a network address according to the lookup table held by the USSD gateway 35. The network address may be any address in a data network, e.g the earlier mentioned data network 7. The USSD gateway 35 converts the USSD message to an SMPP message and submits the SMPP message to the recipient application 10 resident at the network address found in the routing table.

If this routing table does not provide a data network address entry for the concerned MSISDN but instead it provides an URL (Universal Resource Locator), the USSD gateway 35 converts the USSD message to an internal message and forwards this internal message to a Web Server embedded by the second part 31 of the message server FAUMS. The embedded Web Server submits an HTTP (Hyper Text Transaction Protocol) request to the concerned URL, which can be located on an intranet, extranet or the public Internet. This HTTP request will be resolved according to the usual procedures currently available in the aforementioned network types, involving DNS (Domain Name Service) servers for resolving the names contained in the URL. The USSD gateway will subsequently receive a response from either the application 10 or the Web Server.

The USSD gateway 35 converts the received response into an USSD response and sends that back to the mobile station 1 in the second network 11.

The internal communication means between the internal entities of the two parts 30, 31 of the message server FAUMS are irrelevant for this invention and subject to implementation choices. The communication between the first part 30 and the second part 31 of the message server FAUMS is based on standard signaling protocols SS#7, hence the two parts of the message server can be easily integrated in the first and second mobile telecommunications network.

A further important aspect of the present invention is the encryption method provided for services wherein there is a need to protect data, such as the mobile payment services, which may be executed by the application 10.

The encryption method prescribed by this invention is using any conventional or Public Key Infrastructure encryption standard. The method consists of executing both the encryption and decryption at the server side of the application 10 in the first network 2. The mobile station 1 just sends back the encrypted message, hence solving the non-repudiation issue in such a transaction. The data provided by the application 10 is encrypted by the processing means 12, 30, 31 (FSUMS or FAUMS), when needed only partially as indicated by the application 10, and the output, which may be partially encrypted and partially plain, is inserted as a payload in the USSD message and forwarded to the mobile station 1 using an USSD Request operation. The mobile station 1 receives the (partially) encrypted message, the user may enter a special code on the mobile station 1 and sends the message back to the processing means (FSUMS server 12 or first part 30 of FAUMS), which decrypts it and passes it to the application 10. The advantage of this method is that it can be used in combination with any simple mobile device 1 capable of receiving and sending USSD messages, as there is no need for enhanced encrypting and decrypting functionality on the mobile side. Currently there are hundreds of millions of such devices 1 in usage throughout the world. This in combination with the other powerful advantage of the earlier described embodiments of this invention of enabling an application to reach any mobile device by use of an USSD message, creates the ideal space for transactional services for example.

The present invention has been described above using a number of exemplary embodiments, directed at mobile telecommunication systems as in use today, specifically the GSM network. For the person skilled in the art, it will be clear that the present invention is not limited in scope to these embodiments, but extends to all types of network systems. The scope of the present invention is only limited by the features as described in the following claims.

Claims

1. Method for providing communication in a telecommunications system between a first network element (10; 1) and a second network element (1; 10), the first network element (10; 1) forming part of or being connected to an originating telecommunications network (2; 11; 20), and the second network element (1; 10) forming part of or being connected to a recipient telecommunications network (11 ; 20; 2), in which the originating and recipient telecommunications network (2; 11; 20) are interconnected networks, comprising the steps of: - obtaining routing data of the second network element (1 ; 1 ) in the recipient telecommunications network (11; 20; 2) using a first protocol, - forwarding messages from the first network element (10; 1) to the second network element (1; 10) using a second protocol and the routing data, in which the second protocol is different from the first protocol.

2. Method according to claim 1, in which the first network element is a server executing an application (10) and the second network element is a mobile subscriber device (1) subscribed to or visiting the recipient telecommunications network (11; 20), and the communication is initiated by the application (10).

3. Method according to claim 1, in which the first network element is a mobile subscriber device (1) subscribed to or visiting the originating telecommunications network (11; 20) and the second network element is a server executing an application (10), and the communication is initiated by the mobile subscriber device (1).

4. Method according to one of the claims 1, 2 or 3, in which the second protocol is the Unstructured Supplementary Services Data protocol.

5. Method according to one of the claims 1 through 4, in which the first protocol is the MAP protocol section for SMS (Short Message Service) or voice calls.

6. Method according to one of the proceeding claims, in which the second network element (1; 10) is assigned a unique identification in the recipient telecommunications network (11; 20; 2), and the routing data is obtained using the unique identification.

7. Method according to one of the proceeding claims, in which the routing data comprises an identification of a mobile services switching center (13; 23) which is part of the recipient telecommunications network (11; 20; 2) and services the second network element (1; 10).

8. Method according to any one of the proceeding claims, in which the routing data comprises an identification of a Home Location Register (15), which is part of the recipient telecommunications network (11; 2) and services the second network element

9. Method according to any one of the proceeding claims, in which the communication with the second network element (1; 10) using the second protocol is at least partly encrypted, and the method comprises the further steps of receiving data from the first network element (10; 1); encrypting at least partially the received data; inserting the encrypted data in a message according to the second protocol; forwarding the message to the second network element (1; 10); receiving back the message from the second network element (1; 10) after insertion of a special code by the user in the second network element (1; 10); decrypting the received message; passing on the decrypted message to the first network element (10; 1).

10. Telecommunications system, comprising at least an originating and a recipient telecommunications network (2; 11; 20), the originating telecommunications network (2; 11; 20) comprising a first network element (10; 1), the recipient telecommunications network (11; 20; 2) comprising a second network element (1; 10), the telecommunications system further comprising processing means (12; 30, 31) which are arranged to communicate with the originating and the recipient telecommunications network (2; 11; 20) and to execute the method according to any one of the claims 1 through 9.

11. Telecommunication system according to claim 10, in which the first network element is a server executing an application (10) and the second network element is a mobile subscriber device (1) subscribed to the recipient telecommunications network (11; 20), and the processing means are arranged to execute any one of the claims 1, 2 or 4 through 9.

12. Telecommunication system according to claim 10, in which the first network element is a mobile subscriber device (1) subscribed to the recipient telecommunications network (11; 20) and the second network element is a server executing an application (10), and the processing means comprise first processing means which are part of the originating network and second processing means which are part of the recipient network, in which the processing means are arranged to execute any one of the claims 1 or 3 through 9.

13. Telecommunications system according to claim 12, in which the first or second network element (10; 1) is part of a data network (7), which is interconnected with the originating or recipient telecommunications network (2; ' 11 ; 20).

14. Telecommunications system according to one of the claims 10 through 13, further comprising data encryption/decryption means for at least partially encrypting messages, in which the processing means (12; 30, 31) are arranged to execute the further method steps of claim 9.

15. Computer program product comprising executable code, which when loaded on a processing system connected to a telecommunications network (2; 11; 20), enables the processing system to execute the method steps as defined according to one of the claims 1 through 9.