FR2846172A1 - Mobile telecommunication terminal commutation process, involves sending specific message if external package commutation network sends some data to destination of terminal requiring communication in package mode - Google Patents

Abstract

The process involves sending a specific message from a core network of a network (4) to a network of radio access to commutate a terminal towards a network (6) during communication in a circuit mode via the network (4). The message is sent if an external package commutation network sends some data to the destination of the terminal requiring a communication in package mode to ensure simultaneous communication in two modes. An Independent claim is also included for a mobile telecommunication terminal.

Description

METHOD FOR AUTOMATIC SWITCHING OF A BIMODE TERMINAL

TECHNICAL AREA

  The invention relates to the field of telecommunications and relates more specifically to a method of switching a telecommunications terminal between, on the one hand, a first network comprising a radio access network and a core network capable of managing communications in circuit mode and communications in packet mode and in which, during the same communication, said terminal is able to operate only in circuit mode or only in packet mode, and on the other hand, a second network comprising resources allowing said terminal to operate simultaneously in circuit mode and in packet mode during the same communication. The invention also relates to a mobile telecommunication terminal capable of operating in a first network only in circuit mode or only in packet mode and in a second network simultaneously

in circuit mode and in packet mode.

  State of the prior art GSM and UMTS- networks are composed of

  two parts: the core network and the access network.

  In UMTS terminology, the core network is designated by the term CN (for Core Network in English) and the access network is designated by the term UTRAN (for Universal terrestrial Radio Access Network). FIG. 1 represents a detailed view of a GSM network including the part of the network relating to circuit switched services (telephony, data applications on circuits) and the part of the network relating to packet switched services used, for example , for applications accessible via the Internet. The packet switched service is introduced in the GSM standard under the name of GPRS (for General Packet Radio 10 Service). The purely GPRS part of the core network of a GSM network is made up of SGSN (for Serving GPRS Support Node) and GGSN (for Gateway GPRS Support Node). These elements are completely separate from those used for the circuit part. The only functions 15 common to the management of circuit and packet communications are the functions of HLR (for Home Location Register), EIR (for Equipment Identity Register) and

AuC (for Authentication Center).

  The separation of the support for circuit and packet applications in the core network of the GSM network allows telecommunications operators to have a certain flexibility when migrating to GPRS. However, this separation poses some problems linked to the multiplication of equipment which requires the operator to manage its network more complex. Figure 2 shows a detailed view of a UMTS network. In UMTS networks, the functions relating to the circuit and packet parts are grouped within a core network comprising two distinct domains: the CS domain (for Circuit Switched),

  - and the PS domain (for Packet Switched).

  The elements of the core network are therefore divided into three groups illustrated by FIG. 3. The first group corresponds to the CS domain and includes the MSC (for Mobile Service Switching Center) and the VLR (for Visitor Location Register). The second group corresponds to the PS domain and includes the SGSN (for Serving GPRS Support Node) and the GGSN (for Gateway 10 GPRS Support Node). The last group includes the network elements common to the PS and CS domains: the HLR, the EIR and the AuC. In the GSM and UMTS networks, the CS and PS domains are linked by

  through an optional interface (Gs).

  Unlike the GSM network, UMTS network specifications allow a mobile station to establish and maintain multiple connections simultaneously in a single call. Each connection can set up a bearer service 20 with a different QoS quality of service to convey the data flows to two or more media (voice, video,

images, files ...).

  In the GSM / GPRS network, the GPRS communication terminals are classified according to their ability to manage communications in circuit mode and

communications in packet mode.

  Three classes of terminals have been defined: - "Class A" terminals which integrate the DTM functionality (for Dual Terminal Mode) and are characterized by the ability to simultaneously manage communications in circuit mode (voice transmission for example) and packet mode communications (Internet browsing for example). "Class B" terminals which allow the offer of services in packet and circuit mode but not at the same time, and

  - "Class C" terminals which only support packet mode services.

  Note that class B terminals do not integrate the DTM functionality while this functionality is implicit in a UMTS terminal. Consequently, it is not possible to manage simultaneously a circuit mode communication and a packet mode communication with a class B terminal. The problem which the invention attempts to solve arises when a user who is already engaged in communication in packet or circuit mode, wishes to have DTM functionality without having to manually close the GSM / GPRS connection in progress, then manually restore a new one

with a UMTS network.

  The European patent application N002292205.8 25 filed by the applicant on September 9, 2002 describes a solution which allows a mobile terminal to compensate for the absence of DTM functionality during

outgoing calls.

  To this end, the invention described in this request consists in automatically switching to the packet mode network if during a circuit mode communication via the circuit mode network, the terminal requires the establishment of a communication.

in packet mode.

  This solution overcomes the lack of DTM functionality for outgoing calls, that is to say, when the user of a terminal wishes during a communication in circuit mode, to establish a communication in packet mode with the network. This is the case, for example, of a user who wishes to use the same telephone communication to exchange data with a packet switched network.

PRESENTATION OF THE INVENTION

  The invention recommends a method which makes it possible to carry out cross-system switching of a terminal.

  telecommunications to overcome the lack of DTM functionality for incoming calls, that is, when the need for packet mode communication is detected at the network level and not at the level of the user.

  This method makes it possible to switch between, on the one hand, a first network comprising a radio access network and a core network capable of managing communications in circuit mode and communications in packet mode and in which, during a same communication, said terminal is able to operate only in circuit mode or only in packet mode, and on the other hand, a second network comprising resources allowing said terminal to operate simultaneously in circuit mode and in packet mode during a same communication, For this purpose, during a communication in circuit mode via the first network, if an external packet switching network sends data to the terminal requiring communication in packet mode, the core network of this first network send a specific message to the radio access network intended to cause the terminal to switch to the second network to simultaneously ensure communication ion in

  circuit mode and communication in packet mode.

  In a preferred embodiment of the method of the invention, the first network is a network

  GSM / GPRS, and the second network is a UMTS network.

  In this implementation mode, the method comprises the following steps: - the SGSN module in charge of managing packet switched services in the GSM / GPRS network detects data coming from a network

packet switching.

  - Said SGSN module sends to the radio access network (BSS) of the GSM / GPRS network a specific message intended to cause the switching of the

terminal to the UMTS network.

  - said radio access network (BSS) sends

  at the terminal a request for switching over to the UMTS network.

  The invention also relates to a mobile telecommunication terminal capable of operating in a first network only in circuit mode or only in packet mode and in a second network simultaneously in circuit mode and in packet mode comprising means for automatically switching to the second network. if during a communication via the first network, an external packet switched network sends data to said terminal requiring a

  communication in packet mode. 5 BR VE DESCRIPTION OF THE DRAWINGS

  - Figure 1 schematically represents the architecture of a GSM / GPRS network, - Figure 2 schematically represents the architecture of a UMTS network, - Figure 3 schematically represents the distribution in domains of the elements of the core network of a UMTS network, - Figure 4 is a diagram illustrating

  schematically the method according to the invention.

  EXHIBITION OF SIZE OF SPECIFIC EMBODIMENTS

The following description relates to the

  switching of a dual-mode GSM / GPRS-UMTS terminal

  GSM / GPRS network to UMTS network.

  Figures 1 to 3 described above 20 schematically illustrate the architectures

  respective GSM / GPRS and UMTS networks.

  The process can be implemented in any

  User equipment designated by the acronym UE, (for User Equipment in English) and designating a mobile station 25 in a UMTS network.

  To illustrate the process of the invention, it is assumed that the terminal 2 supports GSM / GPRS and UMTS technologies and that the GPRS part of this terminal 2

is "Class B".

  In Figure 4 are shown schematically a mobile terminal 2, a GSM / GPRS network 4, a UMTS network 6, a BSS radio access network 8 for the GSM / GPRS network 4, and an IP server

  external 10 packet switching.

  It is assumed that the mobile terminal 2 is in communication in circuit mode (step 12) with the switch MSC (for Mobile Switching Center) in charge of managing the circuit switched services of the GSM / GPRS network 4. During this communication, data from the external IP network 10 arrives at the GSM / GPRS network 4 (step 14) and is detected (step 16) by the SGSN module in charge of managing packet-switched services in the GSM / GPRS network 4. The SGSN module generates (step 18) a specific message intended to cause the switching of the terminal 2 to the UMTS network 6 which allows the terminal to maintain the communication in circuit mode in progress and to establish a new communication in packet mode with the IP network 10. This specific message is sent (arrow 20) to the BSS 8. In step 22, the GSM / GPRS network 20 sends to the UMTS network 6 a request for the latter to take over the communication . The latter allocates (step 24) the radio resources necessary for the terminal 2. At the same time, the BSS 8 sends (step 26) to the terminal 2 a request for switching to the UMTS network 6. In step 28, the GSM / GPRS network 4 send to the SGSN module of the UMTS network 6 the data packets received from the external IP network 10. In step 30, the SGSN module of the UMTS network 6 transfers the packets to the terminal 2 and takes charge of 30 (step 32) the packet communication with the

  external IP server and communication in circuit mode in progress.

  This inter-system switching procedure is carried out in a manner transparent to the user.

Claims (4)

  1. Method for switching a telecommunications terminal between, on the one hand, a first network comprising a radio access network and a core network 5 capable of managing communications in circuit mode and communications in packet mode and in which , during the same communication, said terminal is able to operate only in circuit mode or only in packet mode, and on the other hand, a second network comprising resources allowing said terminal to operate simultaneously in circuit mode and in packet during a single communication, method characterized in that, during a communication in circuit mode via the first network, if an external packet switching network sends data to the terminal requiring communication in mode packet, the core network of this first network sends a specific message to the radio access network intended to cause switching from the terminal to the second network to simultaneously ensure circuit mode communication   and packet mode communication.   2. Method according to claim 1, characterized in that, the first network is a network   GSM / GPRS, and the second network is a UMTS network.   3. Method according to claim 2, characterized in that it comprises the following steps: 30 - the SGSN module in charge of managing packet-switched services in the GSM / GPRS network (4) detects data coming from a   packet switched network (10).   - Said SGSN module sends to the radio access network (8) of the GSM / GPRS network (4) a specific message 5 intended to cause the switching of the terminal (2) to the UMTS network (6).   - said radio access network (8) sends to the terminal (2) a switchover request to the network UMTS (6).   4. Mobile telecommunication terminal capable of operating in a first network only in circuit mode or only in packet mode and in a second network simultaneously in circuit mode and in packet mode. characterized in that it comprises - means for automatically switching   to the second network if, during a communication via the first network, an external packet switching network sends to said terminal data requiring communication in packet mode.