A METHOD AND A SYSTEM FOR SIGNALLING BETWEEN A DIGITAL MOBILE COMMUNICATION SYSTEM AND A DATA COMMUNICATION NETWORK

Abstract: A method and a system for signalling between a digital mobile communication system and a data communication network is revealed. A user terminal associated with the mobile communication system raises a request for information retrieval from a data terminal in the data communication network and the system carries out steps that comprise recognition of the request for information retrieval, direction of the request to a number retrieval database and forwarding of the request to a conversion database. One preferred embodiment of the invention concerns a GSM system. The number retrieval database FNR has been implemented in such GSM systems. All connections in the system, both speech and non-speech, are connected with the aid of FNR, which forwards a connections request to the HLR mobile switching centre to which the receiving terminal/subscriber is connected.

Description: A METHOD AND A SYSTEM FOR SIGNALLING BETWEEN A DIGITAL MOBILE COMMUNICATION SYSTEM AND A DATA COMMUNICATION NETWORK TECHNICAL AREA The present invention concerns methods and systems for managing services in telecommunication and data 5 communication networks. The invention concerns in particular connection of services. INTRODUCTION Users of mobile terminals desire in many cases to have access to a wide and varied range of services: everything 0 from apparently simple services such as forwarding and voice mail to more advanced services such as, for example, Internet access. These services may be directly accessible in the mobile network to which the user is connected, or in other networks that are connected to the 5 mobile network in which the user is located. Furthermore, a situation that often occurs is that the user is connected to one network that the user only visits temporarily, that is, the user is in what is known as "roaming" mode. 0 It is true that these desires are met within the framework of existing technology in that the mobile switching centres in the networks of mobile systems cope with connections, etc., in order to provide as far as is possible access to the services that the user desires. 5 However, these solutions create a heavy load, that is, they require a great deal of processor power in the subsystems, such as SSF in the GSM system, that are used during the connections. For example, in the case in which the GSM system is considered, problems are 0 associated with users who are in roaming mode. In order to make possible connection of services in Internet-based networks, for example with the aid of the SIP protocol, the solution that is currently chosen is to assign to all users an IN category, which in this way makes it possible to start up the SSF functions in the mobile switching centre that manages connection to the service desired. This means, among other things, that roaming users cannot use the service, since this type of IN category cannot be transferred between the networks of different operators. Furthermore, this solution involves problems of the SSF functional unit often becoming overloaded and the problem that a user who is already in a situation in which an IN category has previously been assigned to him or her cannot use the service. DESCRIPTION OF THE INVENTION The present invention aims to alleviate problems that are associated with the known technology in association with connection of services to a user terminal in a mobile communication network. This is achieved with a method and a system according to the attached claims. A method for control of signalling between a digital mobile communication system and a data communication network is revealed. A user terminal associated with the mobile communication system raises a request for information retrieval from a data terminal in the data communication network and the system carries out steps that comprise recognition of the request for information retrieval, direction of the request to a number retrieval database that exists in a switching centre of a mobile communication system, forwarding of the request to a conversion database, in which conversion of the request takes place according to an existing communication protocol for connection initiation that is present in the data communication network. A reply from the data terminal is received, which is then subjected to a procedure for recognition whereby further management of the communication with the user terminal depends on the information that has been received from the data terminal . One preferred embodiment of the invention concerns a GSM system that comprises a mobile services switching centre that comprises a number of functional components with which one skilled in the art is fully familiar. The number retrieval database FNR has been implemented in such GSM systems and is a central part of the implementation of the invention. All connections in the system, both speech and non-speech connections, are connected with the aid of FNR, which forwards a request for connection to the HLR mobile services switching centre to which the receiving terminal/subscriber is connected. The invention is based on the innovation of replacing, when connection to a service is required, the address that FNR uses in order to address the destination by an address of the service. This takes place by replacing the HLR address of the destination (the SCCP address) with an SCCP address of an SIP agent. Such a solution means that the subscribers/users of a mobile operator can obtain access to services that are available in packet-switched networks that are connected with the aid of SIP, and that the users who are in roaming mode in the networks of other operators can also obtain this access to SIP-initiated services in packet- switched networks. Examples of services that can be provided with the aid of connections that are carried out according to the invention are: call-blocking for incoming calls, call filtering, Freephone, number portability, call distribution, etc. One advantage of the present invention is that services can be provided rapidly and flexibly to all subscribers in the network including those subscribers that A temporarily roam in another network, since FNR is used instead of SSF for the connection. A second advantage of the present invention is that the problem with the load on the SSF units disappears, and that conflicts on assignment of IN category can be avoided . BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows schematically a system according to the present invention. Figure 2 shows schematically signalling between units according to a first embodiment of the invention. Figure 3 shows schematically signalling between units according to a second embodiment of the invention. PREFERRED EMBODIMENTS Figure 1 illustrates a system according to the invention in a manner familiar to one skilled in the art. A mobile terminal 101, which can be, for example, a telephone or another type of more or less intelligent terminal, is connected to a first mobile network 102 through a radio interface, etc., (not shown) according to known GSM technology. The functional units that are required for traffic between users, such as the mobile terminal 101, to work are present in the first mobile network 102. These units are: a mobile system switching centre 110, a mobile system switching centre with gateway function 112 and a home location register 111. As is illustrated in Figure 1, the first mobile network 102 is connected to a second mobile network 107 to which a user 106 may be connected in the same way as to the first mobile network 102. A user 106 who has his or her home in the first mobile network 102 and visits the second mobile network 107, as is schematically illustrated in Figure 1, is then said to be in "roaming" mode . The first mobile network 102 is connected to a data communication network 103 via a gateway functional unit 104. A number of parties that provide services are present in the data communication network 103, which, for example, may be a local network or a part of the Internet. These service providers are illustrated very schematically by a service server 105. Communication with parties connected to the data communication network 103 takes place according to the IP protocol as is known to one skilled in the art, while communication within the mobile networks 102, 107 occurs according to GSM-specific protocols. Communication, comprising signalling, is illustrated in Figure 1 by round symbols between the various units. MAP communication 120 and ISUP communication 121 are used within the mobile networks 102, 107. Communication between the first mobile network 102 and the gateway function 104, and communication between the mobile networks 102, 107 also occur according to MAP 122, 123. Since the gateway function 104 communicates with an IP network, in the form of the data communication network 103, information is exchanged between the gateway function 104 and the data network 103 according to standard Internet protocols. Within the framework of this invention, communication takes place according to SIP 124. Figures 2 and 3 illustrate in a certain amount of detail signalling between the units that are shown in Figure 1. Reference numbers in Figures 2 and 3 have the same significance as equivalent numbers in Figure 1. Figure 3 also shows a short message service centre (SMSC) 250. Figure 2 shows how a call connection is established via an FNR/HLR home location register 111 and where a subscriber uses a service server in a data communication network that is connected to a mobile network. The signalling sequence can be illustrated with the aid of the following table: Figure 3 shows how a short message service (SMS) signal is established via an FNR/HLR home location register 111, and it shows how a subscriber uses a service server in a data communication network that is connected to a mobile network. The signalling sequence can be illustrated with the aid of the following table: It is true that the invention has been exemplified in the embodiments described above using signalling in GSM systems with the use of specifically denoted GSM functions. This, however, must not be seen as a limitation. The invention can be applied in all systems, for example D-AMPS systems, in which equivalent functions are implemented.

Claims: CLAIMS 1. Method for control of signalling between a digital mobile communication system and a data communication network, whereby a user terminal associated with the mobile communication system raises a request for information retrieval from a data terminal in the data communication network, comprising: - recognition of the request for information retrieval, - direction of the request to a number retrieval database existing in a switching centre of a mobile communication system, - forwarding of the request to a conversion database in which conversion of the request takes place according to an existing communication protocol for connection initiation that is present in the data communication network, - reception of a reply from the data terminal, - recognition of the reply received whereby further management of the communication with the user terminal depends on the information that has been received from the data terminal. 2. Method according to claim 1, whereby the information retrieval is related to forwarding of a connection that the user terminal intends to establish with a second user terminal in a communication network. 3. Method according to claim 1 or 2, whereby the request for information retrieval is converted from a communication protocol that is present in the mobile communication system to the communication protocol for connection initiation that exists in the data communication network. 4. Method according to any of the claims 1-3, whereby the communication protocol present in the mobile communication system is MAP. 5. Method according to any of the claims 1-4, whereby the communication protocol present in the data communication system is SIP. 6. Method according to any of the claims 1-5, whereby the mobile communication system functions according to GSM and the number retrieval database is an FNR. 7. The method according to claim 6, whereby addressing in the FNR is carried out using SCCP addresses and the request is addressed to the conversion unit in the form of its SCCP address. 8. System for control of signalling between a digital mobile communication system and a data communication network, whereby a user terminal associated with the mobile communication system raises a request for information retrieval from a data terminal in the data communication network, comprising: - means for recognition of the request for information retrieval, - means for direction of the request to a number retrieval database in a switching centre of a mobile communication system, - means for forwarding of the request to an conversion database in which conversion of the request takes place according to an existing communication protocol for connection initiation that is present in the data communication network, - means for reception of a reply from the data terminal, - means for recognition of the reply received whereby further management of the communication with the user terminal depends on the information that has been received from the data terminal. 9. System according to claim 8, whereby the mobile communication system comprises means for managing the MAP communication protocol. 10. System according to claim 8 or 9, whereby the mobile communication system is a GSM system and the number retrieval database is an FNR.

Inventors: AAHLIN JOACHIM, EKSTROEM ROGER, AAHLIN, JOACHIM, EKSTROEM, ROGER
Applicants: AAHLIN JOACHIM, EKSTROEM ROGER, TELIA AB PUB, AAHLIN, JOACHIM, EKSTROEM, ROGER, TELIA AB (PUB)
Application year: 2001
Main classification: H04Q7
IPC codes: H04Q3, H04W76, H04W80