FR2887721A1 - Internet protocol multimedia subsystem type data storing method for e.g. fixed telephone, involves communicating storage request having secondary private and public identifiers of byte for recording in correspondence to allotted address - Google Patents

Abstract

The method involves communicating a secondary private identifier, a primary public identifier of a client and an allotted contact address of a storage request to an Internet protocol multimedia subsystem type data storage equipment (ES) to determine if the first and second bytes have the private identifier and IRS secondary value representing the type of access network. Another storage request having the private identifier and a secondary public identifier of the second byte is communicated to the equipment to carry out their recording in correspondence to the allotted contact address. Independent claims are also included for the following: (1) an Internet protocol (IP) multimedia subsystem (IMS) type data storage equipment for a communication network (2) a multimode communication terminal comprising an ISIM type card.

Description

The invention relates to communication networks connected to networks

  access of different types, and more particularly the recording of IMS-type information relating to the multimode communication terminals of the clients of these communication networks.

  Here multimode communication terminal (hereinafter called multimode terminal) means any fixed or mobile (or portable) communication equipment capable of connecting to access networks of at least two different types (connected to its network). of attachment), by means of at least two network interfaces corresponding to said different types, in order to exchange data in the form of signals, either with another terminal or network equipment, via their network (s) of attachment , or with its own home network. It may therefore be, for example, multimode mobile phones, or desktop or portable computers or digital personal assistants (PDAs) equipped with a multimode communication module.

  In addition, access networks of different types are here understood to mean access networks using different transmission technologies, for example at least two different radio access technologies such as GPRS / EDGE, UMTS (or HSDPA). ), WLAN (Wireless Local Area Network, for example Hyperlan (according to the ETSI standard) or 802. 11 (according to the IEEE standard)), WMAN (Wireless Metropolitan Area Network, for example 802.16 according to the IEEE standard), or Bluetooth or at least two wired access technologies of the LAN type (for Local Area Network), or at least one radio access technology and at least one wired access technology of the LAN type .

  As known to those skilled in the art, when a terminal, attached to a communication network, connects to an access network, the latter assigns it an IP contact address, such as 169.25.26.27. The terminal must then register its IP contact address with a recording equipment (IMS information) of its home network, managing the Internet links (or IP) within a so-called IMS layer (for IP Multimedia Subsystem - IP multimedia subsystem) and usually called S-CSCF (Serving-Call Session Control Function).

  This record 1MS consists of associating at the level of the S-CSCF the public identifier IMS of the client (which uses the terminal object of the recording), generally called IMPU (for IMs Public User Identity) and presenting for example in the form kim @ home.com, and the IP contact address that has been assigned to the terminal by a 2 2887721 access network.

  The registration procedure is done in four steps. In a first step, the terminal generates, for the S-CSCF, a first registration request comprising the public identifier of the client, the assigned IP contact address and a private identifier, generally called IMPI (for IMs Private user Identity ) and for example in the form IMP11. In a second step, the S-CSCF receives the first registration request, stores the information it contains and transmits at least the public identifier (IMPU) and the private identifier (IMPI) to an information storage device. IMS io of the communication network, generally called HSS (for Home Subscriber Server and storing for each client of the network a byte including its public identifier (IMPU), its private identifier (IMPI) and a primary value of IRS (Implicit Registration Set - implicit registration set) In a third step the HSS compares the IMS information received from the S-CSCF with that it is stored and, if the received IMS information matches that stored in one of its bytes, it acknowledges the IMS information and generates for the S-CSCF a second registration request including at least the private identifier (IMPI) and the public identifier (IMPU) so that it proceeds to them r registration in correspondence of the assigned IP contact address.

  As long as a multimode terminal is connected to a single access network, the IMS registration procedure is well suited. However, when a multimode terminal is connected to more than one access network of different types, the IMS registration procedure does not allow it to be the subject of multiple IMS records with the S-CSCF equipment. Indeed, when a multimode terminal is connected to an access network of a first type, the SCSCF equipment associates the public identifier (IMPU) of its user with the first IP contact address that has been assigned to it by this access network of a first type. If this multimode terminal then connects to an access network of a second type, the S-CSCF equipment will have to associate the public identifier (IMPU) of its user with the second IP contact address which has been assigned to it. by this access network of a second type. However, this is prohibited by technical specifications TS 24.229 (≈5.4.1.2) 3GPP. The SCSCF equipment is then obliged to delete the association of the public identifier (IMPU) and the first IP contact address, which amounts to de-registering the terminal relative to the access network of the first type, and then associating the public identifier (IMPU) to the second IP contact address in order to register the terminal relative to the access network of the second type.

  3 2887721 However, multiple IMS records would be useful in some situations because they could allow, by associating the same public identifier (IMPU) with several contact IP addresses (assigned to the same multimode terminal), to hide from users the type of access network that is used by the multimode terminal of another user, in particular.

  The invention therefore aims to overcome the aforementioned drawback, and more specifically to allow multiple IMS records of multimode terminals connected to multiple access networks.

  To this end, it proposes a method dedicated to the recording of information of the IMS type, with a recording equipment (of the S-CSCF type) of a communication network connected to access networks of the least two different types of a multimode communication terminal of a client of the communication network. This method is characterized in that it consists in: storing in an information storage device (HSS type) of the communication network, for each client (having a primary public identifier associated with a primary private identifier and a primary value of IRS) and for each type of access network, a first byte including its primary public identifier, a secondary private identifier and a secondary value of IRS representative of the type of access network, and a second byte comprising the secondary private identifier, the secondary value of IRS and a secondary public identifier, then - in case of assignment to the terminal of a client of an IP contact address, by an access network of the one of the types: - to generate, at the level of the terminal and at the destination of the recording equipment (S-CSCF), a first registration request comprising a secondary private identifier, the primary public identifier of the client and the ad assigned to the storage equipment (HSS) at least the identifiers contained in the first registration request so that it determines whether first and second bytes each contain the secondary private identifier and a same secondary value of IRS, the first byte to further include the primary public identifier, and if so that it generates a second registration request including at least the secondary private identifier and the secondary public identifier contained in the second byte determined for the recording equipment (S-4 2887721 CSCF), so that it records them in correspondence of the assigned IP contact address.

  The method according to the invention can comprise other characteristics that can be taken separately or in combination, and in particular: s - upon receipt of a first registration request the recording equipment (S-CSCF) can also communicate to the storage equipment (HSS) the assigned IP contact address it contains. In this case, the storage equipment (HSS) can integrate in the second registration request this assigned IP contact address; lo the terminal wishing to proceed with an IMS record may previously generate a secondary private identifier from the primary private identifier of the client that uses it, which is stored in an ISIM Subscriber Identification Module (ISIM) card of the terminal , and information about the type of access network that has assigned the new IP contact address; each secondary private identifier can be generated in the ISIM-type card or by a module for calculating the terminal, powered by the ISIM-type card.

  The invention also proposes an information storage device of the IMS type (S-CSCF), for a communication network connected to access networks of at least two different types, comprising: storage means storing, for each client of the communication network (having a primary public identifier associated with a primary private identifier and a primary value of IRS) and for each type of access network, a first byte including its primary public identifier, a a secondary private identifier and an IRS secondary value representative of the type of access network, and a second byte comprising the secondary private identifier, the secondary value of IRS and a secondary public identifier, and - loaded processing means, when they receive a secondary private identifier and a primary public identifier of a client, i) determine whether the storage means stores first and second multiplets cont each taking the secondary private identifier and the same secondary value of IRS, and if the first byte further comprises the primary public identifier, and if so, ii) generating a registration request including at least the identifier secondary private and the secondary public identifier contained in the second determined multiplet.

  The information storage equipment according to the invention may comprise other characteristics that may be taken separately or in combination, and in particular: when its processing means receive an IP contact address assigned to a communication terminal; a client in addition to the secondary private identifier and primary public identifier of the client, they may be responsible for integrating into the request the assigned IP contact address; at least some of the secondary private identifiers may be primary private identifiers enriched with selected information. For example, the information selected may be representative of the type of the access network that designates the secondary value of IRS stored in the first and second bytes containing the secondary private identifier that includes it; at least some of the secondary public identifiers may be primary public identifiers enriched with selected information. For example, the selected information may be representative of the type of the access network that designates the secondary value of IRS stored in the second byte containing the secondary public identifier that includes it.

  The invention also proposes a multimode communication terminal, comprising an ISIM type card (storing at least one primary client private identifier) and a loaded message generation module, when a new IP contact address is assigned to its terminal. by an access network of a given type, generating, for the recording equipment (S-CSCF) of the communication network to which its terminal is attached, a first registration request comprising a so-called secondary private identifier, generated from the primary private identifier stored in the ISIM type card and information on the type of the access network that has assigned the new IP contact address, a public identifier and the new assigned IP contact address.

  This terminal may also include a calculation module responsible for generating each secondary private identifier from the primary private identifier that is stored in the ISIM type card. In a variant, the ISIM-type card may be responsible for generating each secondary private identifier from the primary private identifier that it stores.

  Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawing, in which the single figure schematically illustrates a part of a communication network connected to two access networks, to which is connected an example of multimode terminal according to the invention, and equipped with an IMS message recording equipment and an embodiment of an IMS information storage equipment according to the invention. the invention. The attached drawing may not only serve to complete the invention, but also contribute to its definition, if any.

  The object of the invention is to enable multiple IMS records of multimode terminals attached to a communication network via at least two access networks of different types.

  FIG. 1 shows a communication network R1 consisting of a core network RC1 and a first access network RAI, a second access network RA2 connected to the core network. RC1, and a multimode communication terminal TM, capable of connecting to the first RAI and second RA2 access networks through two dedicated network interfaces (not shown).

  In the following, we consider as a nonlimiting example that the communication network R1 is a mobile network (or cell) type GPRS (its own (first) access network RAI is therefore radio type), and the second access network RA2 is of the wireless local area network (WLAN) type, for example a Hyperlan network (according to the ETSI standard) or 802.11 (according to the IEEE standard). But, the invention is not limited to these types of network. It concerns all types of access network supporting Internet connections (IP), including UMTS (or HSDPA) radio access networks, Wireless Metropolitan Area Network (WMAN), such as 802.16 according to the IEEE standard. , or Bluetooth, as well as wired access networks of the LAN type (for Local Area Network), and combinations of network (s) of radio access and network (s) of access wired LAN type.

  Furthermore, it is considered in the following that the multimode terminal is a dual-mode mobile phone (here GPRS / WLAN) capable of connecting to the first RAI and second RA2 access networks (here both radio-type, remote control). 'example). However, the invention is not limited to this type of multimode terminal. It concerns in fact any fixed or mobile (or portable) communication equipment capable of connecting to access networks of at least two different types in order to exchange data in the form of signals with another terminal or equipment. network, and in particular multi-mode fixed or mobile telephones, or desktop or portable computers or digital personal digital assistants (or PDAs) equipped with a radio and / or wired LAN type multimode communication module.

  The core network RC1 conventionally comprises a so-called IMS layer (for IP 7 2887721 Multimedia Subsystem - IP multimedia subsystem), notably comprising an IMS EE information recording equipment, such as an equipment of the S-CSCF type ( for Serving-Cali Session Control Function), and a layer of applications and services, including in particular a data storage equipment ES relating to the clients of the communication network R1, for example a HSS (for Home Subscriber Server) type equipment. The storage equipment ES comprises a processing module MT coupled to storage means BD1.

  The storage means BD1 can be arranged in any form, and especially in the form of a memory or a database. They are responsible for storing the information relating to the clients of their communication network R1, and in particular certain IMS information.

  More specifically, the database BD1 stores for each client a byte comprising a primary public identifier (or generic) of IMPU type (for IMs i5 Public User identity), which is for example in the form kim@home.com, a primary private identifier (or generic) type IMPI (for IMs Private user Identity), which is for example in the form IMP11 and which is known only by the communication network R1, and a value called IRS (for Implicit Registration Set - eg implicit registration set), eg 0 (zero).

  Moreover, in anticipation of possible multiple connections of the multimode terminals of the network clients to different types of access networks attached to the communication network R1, the database BD1 stores for each client and for each type of access network, on the one hand, a first byte comprising its primary public identifier (or generic) of the IMPU type (for example kim@home.com), a secondary private identifier and a secondary value of IRS representative of the type of access network, and secondly, a second byte comprising the secondary private identifier, the secondary value of IRS and a secondary public identifier.

  At least some secondary private identifiers, and preferably all, are for example private primary identifiers which are enriched by a selected information. For example, the enrichment consists in adding to the primary private identifier information representative of the type of the access network. Thus, if the primary private identifier of a client is IMP11 and the access network is of GPRS type, the secondary private identifier may be of the IMPI1_GPRS type. If now the primary private identifier of the client is still IMP11 and the access network 2887721 is now WLAN type, then the secondary private identifier may be of the type IMPII_WLAN.

  In addition, at least some of the secondary public identifiers, and preferably all, are for example primary public identifiers that are enriched by a selected information. For example, the enrichment consists in adding to the part dedicated to the name in the primary public identifier information representative of the type of the access network. Thus, if the primary public identifier of a client is kim@home.com and the access network is of GPRS type, the secondary public identifier can be of the type kim_gprs@home.com. If now the client's primary public identifier is still kim@home.com and the access network is now WLAN, then the secondary public identifier may be of the kim2vlan @ home type. com.

  Of course, the enrichment can be done by means of other selected information, such as numbers or more generally alphanumeric characters representative each of a type of access network.

  When the primary value of IRS is a digit, one can also choose secondary values of IRS of type digit. For example, one can assign as secondary value of IRS to the first access network (GPRS) RAI the value 1 (one) and as secondary value of IRS to the second access network (WLAN) RA2 the value 2 (two ).

  Table 1 below shows an example of storage format in the database BD1 of the data IMS relating to a client (kim) of the communication network R1, in anticipation of the connection of its dual-mode telephone TM to first RAI and / or second RA2 network (x) access.

Table 1

IMPI IMPU IRS

  IMPII kim@home.com 0 IMPI1_GPRS kim@home.com 1 IMPI1_GPRS Kim_gprs @ home. com 1 IMPI1 WLAN Kim@home.com 2 IMPI1 WLAN Kimwlan@home.com 2 Each dual-mode telephone TM, belonging to a client of the communication network R1, comprises a card of ISIM type (ISM Subscriber Identification Module) Cl, in which the customer's primary private identifier is stored (for example 9 2887721 IMPl1), and an MG message generation module coupled to the ISIM C1 type card.

  The MG message generation module is loaded, whenever a new IP contact address is assigned to its dual-mode telephone TM by an access network of a given type (RAI or RA2), to generate a first request for a message. recording D1 i to the recording equipment EE (of the communication network RI to which its dual-mode telephone TM is attached). The index i denotes here an access network. Thus, if the dual-mode telephone TM connects to the first access network RAI, the index i is for example equal to 1 (one) and the first registration request is referenced D11. If the two-mode telephone TM then connects to the second access network RA2, the index i is for example equal to 2 (two) and the first registration request is referenced D12.

  Each first registration request D1i includes a secondary private identifier (for example IMP11_gprs, if i = 1), the primary public identifier of the customer who uses the dual-mode telephone TM (for example kim@home.com) and the address of IP contact that has been assigned to the dual-mode telephone TM by the access network (eg RAI) to which it has just connected.

  The secondary private identifier is generated by the dual-mode telephone TM from the primary private identifier, which is stored in its ISIM card Cl, and the type of the access network that has assigned the new IP contact address. It is of course generated in the same way as those stored in the BD1 database of the storage equipment ES. This generation can be done in at least two ways.

  A first way is to arrange the ISIM card Cl type so that it generates the secondary private identifier from the primary private identifier and information on the type of access network that has assigned the new IP contact address, for example by enrichment as described above.

  A second way is to provide a calculation module MC, for example implanted in the generation module MG, as illustrated in the single figure, and responsible for generating each secondary private identifier from the primary private identifier which is stored in the ISIM card Cl type and information on the type of access network that has assigned the new IP contact address, for example by enrichment as described above.

  Each time the dual-mode telephone TM connects to a new access network, the latter assigns it an IP contact address that it must register with the recording equipment EE of its home network R1.

  The registration procedure is carried out in four steps which will be described below with reference to the single figure. In the following it is considered that the dual-mode telephone TM has just connected to the first RAI access network (GPRS). In a first step, the generation module MG of the bimodal telephone TM generates (arrow F11) a first registration request D11 comprising: the primary public identifier (IPMU here equal to kim@home.com) of the client (kim) , the IP contact address (here 169.25.26.27) allocated to the dual-mode telephone TM by the first access network RAI, and the secondary private identifier (IMPI, here equal to IMPI1_GPRS), generated from the primary private identifier (1MP11) which is stored in the ISIM IC type card and information designating the first RAI access network.

  Then the dual-mode telephone transmits (arrow F12) the first registration request D11 to the recording equipment EE of its home network R1.

  In a second step, the recording equipment EE: receives the first recording request D1, then - extracts the information it contains by means of a recording module ME in order to store them in memory means BD2 (which can be arranged in any form, and especially in the form of a memory or a database, and which are responsible for storing the IMS information relating to the registered multimode terminals of the clients of the communication network RI), and finally - transmits to the storage equipment ES of its communication network R1 (arrow F13) at least the primary public identifier (kim@home.com) and the secondary private identifier (IMPI1_GPRS), as well as preferably the IP contact address (169.25.26.27), in particular for authentication.

  In a third step the processing module MT of the storage equipment ES accesses the database BD1 in order to determine whether it stores a first and a second byte (IMPI, IMPU, IRS) which each contain the secondary private identifier (IMPI1_GPRS) received and the same secondary value of IRS (here equal to 1) and if this first byte further comprises the primary public identifier (kim@home.com) received.

  If this is not the case, then the processing module MT refuses to acknowledge (or authenticate) the IMS information received from the recording equipment EE and it 2887721 addresses to the latter a message of refusal of acknowledgment .

  On the other hand, if there are indeed a first and a second byte (IMPI, IMPU, IRS) which verify the two aforementioned conditions, the processing module MT acknowledges the information! MS received from the recording equipment EE by generating a second registration application D21. This second registration request D21 comprises at least the secondary private identifier (IMPI_GPRS) and the secondary public identifier (kim_gprs@home.com) contained in the second byte which verifies the aforementioned first condition, and preferably the address IP contact (169.25.26.27) received from the EE recording equipment.

  Then, the storage equipment ES transmits the second registration request D21 to the recording equipment EE (arrow F14), so that it records them in its database BD2. More precisely, the recording module ME of the recording equipment EE stores in the database BD2 the secondary private identifier (IMPI_GPRS) and the secondary public identifier (kim_gprs@home.com), contained in the second registration request D21, in correspondence of the IP contact address (169.25.26.27), also contained in the second registration request D21.

  The dual-mode telephone TM is then registered relative to the first access network RAI with the recording equipment EE. In other words, the communication network R1 now knows what type of access network is connected to the dual-mode telephone TM.

  Following this registration procedure, the IMS information, which is related to the recording of the dual-mode telephone TM with the recording equipment EE and which is stored in the database BD2, is grouped in the given table n 2. below.

Table 2

  IMPI IMPU IP contact address IMPI1GPRS Kim_gprs@home.com 169.25. 26.27 If a few times later the dual-mode telephone TM connects to the second RA2 access network (WLAN), it receives from the latter (as illustrated in the single figure) a new IP contact address (here equal to 172.15. ). He must then register his new connection (WLAN) with the EE recording equipment. To do this, it must initiate a new registration procedure similar to the previous 12 2887721 (relating to the GPRS connection).

  In a first step, the generation module MG of the bimodal telephone TM generates (arrow F21) a first registration request D12 comprising: the primary public identifier (IPMU here equal to kim @ home. Com) of the client s (kim ), the IP contact address (here 172.15.16.17) assigned to the dual-mode telephone TM by the second access network RA2, and the secondary private identifier (IMPI, here equal to IMPI1 WLAN), generated from the primary private identifier (IMPI1) which is stored in the ISIM IC type card IC and information designating the second access network RA2.

  Then the two-mode telephone transmits (arrow F22) the first registration request D12 to the recording equipment EE of its home network R1.

  In a second step, the recording equipment EE: - receives the first registration request D12, then - extracts the information it contains by means of the recording module ME in order to store them in the storage means BD2 , and finally -transmits to the storage equipment ES of its communication network R1 (arrow F23) at least the primary public identifier (kim@home.com) and the secondary private identifier (IMPI1 WLAN), as well as preferably the IP contact address (172.15.16.17).

  In a third step the processing module MT of the storage equipment ES accesses the database BD1 in order to determine whether it stores a first and a second byte (IMPI, IMPU, IRS) which each contain the secondary private identifier (IMPI1 WLAN) received and the same secondary value of IRS (here equal to 2) and if this first byte further comprises the primary public identifier (kim@home.com) received.

  If this is not the case, then the processing module MT refuses to acknowledge (or authenticate) the IMS information received from the recording equipment EE and it sends the latter an acknowledgment of refusal message.

  On the other hand, if there are indeed a first and a second byte (IMPI, IMPU, IRS) which verify the two aforementioned conditions, the processing module MT acknowledges the IMS information received from the recording equipment EE by generating a second application for registration D22. This second registration request D22 comprises at least the secondary private identifier (IMPI_WLAN) 13 2887721 and the secondary public identifier (kimwlan@home.com) contained in the second byte which verifies the first aforementioned condition, and preferably IP contact address (172.15.16.17) received from the recording equipment EE.

  Then, the storage equipment ES transmits the second registration request D22 to the recording equipment EE (arrow F24), so that it records them in its database BD2. More precisely, the recording module ME of the recording equipment EE stores in the database BD2 the secondary private identifier (IMPI_WLAN) and the secondary public identifier (kim wlan@home.com), contained in the second request Zo registration D22, in correspondence of the IP contact address (172.15.16.17), also contained in the second registration application D22.

  The dual-mode telephone TM is then not only registered relative to the first RAI access network with the recording equipment EE, but also with respect to the second access network RA2.

  Following this new registration procedure, the IMS information, which relates to the dual-mode telephone records TM with the recording equipment EE and which are stored in the database BD2, are grouped together in the given Table 3 below.

Table 3

  IMPI IMPU IP contact address IMPI1_GPRS Kim_gprs@home.com 169. 25.26. 27.16.15.17 The multiple IMS records of the multimode terminals of the clients of the R1 communication network can thus be continued with each access network connected to the latter, without this leading to a de-registration procedure. at the level of the EE recording equipment.

  The processing module MT of the recording equipment EE according to the invention, and / or the message generation module MG and the possible calculation module MC of the multimode terminal according to the invention can be implemented in the form electronic circuits, software (or computer) modules, or a combination of circuits and software.

  The invention is not limited to the embodiments of recording equipment, multi-mode terminals and multiple IMS recording method described above, only by way of example, but encompasses all variants that may consider those skilled in the art within the scope of the claims below.

  Thus, in the foregoing, an exemplary implementation of the invention has been described in the case of two radio access networks of different types. But the invention is not limited to this type of situation. It concerns all the situations in which an IMS communication network is attached to at least two access networks of different types, such as for example at least two radio access networks of different types, or at least two networks of networks. wired access of different LAN type, or at least one radio access network and at least one wired lan LAN access network.

Claims (1)

2887721 CLAIMS   1. A method for recording information of the IMS type, with a recording equipment (EE) of a communication network (R1) connected to access networks (RA1, RA2) of at least two different types of a multimode communication terminal (TM) of a client of said communication network (R1), characterized in that it consists in storing in an information storage equipment (ES) of said communication network ( R1), for each client having a primary public identifier associated with a primary private identifier and a primary value of IRS, and for each type of access network (RA1, RA2), a first byte comprising its public identifier primary, a secondary private identifier and an IRS secondary value representative of said type of access network, and a second byte comprising said secondary private identifier, said secondary value of IRS and a secondary public identifier, then in case of assignment through a network of ccès (RAi) of one of said types of an IP contact address at the terminal (TM) of a client, to generate at said terminal (TM) and to said recording equipment (EE) a first request with a secondary private identifier, the primary public identifier of said client and said assigned IP contact address, and then communicating to said storage equipment (ES) at least said identifiers contained in said first registration request so that it determines whether first and second bytes each contain said secondary private identifier and a same IRS secondary value, said first byte further including said primary public identifier, and if so generates to said recording equipment (ES) a second registration request comprising at least said secondary private identifier and the secondary public identifier contained in the second determined multiplet so that he shall register in correspondence of said assigned IP contact address.   2. Method according to claim 1, characterized in that upon receipt of a first request said recording equipment (EE) also communicates to said storage equipment (ES) said assigned IP contact address that it contains, and said storage equipment (ES) integrates into the second request said assigned IP contact address.   3. Method according to one of claims 1 and 2, characterized in that a terminal (TM) wishing to perform a record first generates a secondary private identifier from the primary private identifier of the client who uses it, 16 2887721 which is stored in an ISIM card (IC) of said terminal (TM), and information on the type of access network (RAi) that has assigned the new IP contact address.   4. Method according to claim 3, characterized in that each secondary private identifier is generated in said ISIM card (IC).   5. Method according to claim 3, characterized in that each secondary private identifier is generated in said terminal (TM) by a computing module (MC) fed by said ISIM card (IC).   6. IMS (ES) type information storage equipment for a communication network (RI) connected to access networks (RA1, RA2) of at least two different types, characterized in that it comprises i) storage means (BD1) capable of storing, for each client of said communication network (R1), having a primary public identifier associated with a primary private identifier and a primary value of IRS, and for each type an access network (RA1, RA2), a first byte comprising its primary public identifier, a secondary private identifier and an IRS secondary value representative of said type of access network, and a second byte comprising said secondary private identifier, said secondary value of IRS and a secondary public identifier, and ii) processing means (MT) arranged, in the event of receiving a secondary private identifier and a primary public identifier of a client, for determining in said way s (BD1) if they store first and second bytes each containing said secondary private identifier and the same secondary value of IRS, and if said first byte further comprises said primary public identifier, and if so to generate a registration request comprising at least said secondary private identifier and the secondary public identifier contained in the second determined byte.   7. Equipment according to claim 6, characterized in that receiving an IP contact address assigned to a multimode communication terminal (TM) of a client in addition to the secondary private identifier and primary public identifier of said client, said Processing means (MT) are arranged to integrate in the request said IP contact address assigned.   8. Equipment according to one of claims 6 and 7, characterized in that at least some of the secondary private identifiers are primary private identifiers enriched with a selected information.   9. Equipment according to claim 8, characterized in that said selected information is representative of the type of the access network (RA1, RA2) that 17 2887721 designates the secondary value of IRS stored by said storage means (BD1) in the first and second bytes containing the secondary private identifier that includes it.   10. Equipment according to one of claims 6 to 9, characterized in that at least some of the secondary public identifiers are primary public identifiers enriched with selected information.   11. Equipment according to claim 10, characterized in that said selected information is representative of the type of access network (RA1, RA2) that designates the secondary value of IRS stored by said storage means lo (BD1) in the second byte containing the secondary public identifier that contains it.   12. Multi-mode communication terminal (TM), comprising an ISIM type card (IC), storing at least one primary client private identifier, and a message generation module (MG) specific, in case of assignment to said terminal ( TM) is a new IP contact address by an access network (RAi) of a given type, connected to a communication network (RI) comprising an IMS recording equipment (EE) and whose user said terminal (TM) is a client, to generate for said recording equipment (EE) a first registration request comprising a private identifier, a public identifier and said new assigned IP contact address, characterized in that said module message generation (MG) is arranged to integrate in each first registration request a so-called secondary private identifier, generated from said primary private identifier stored in said ISIM type card (IC) and rela information. the type of access network (RAi) that assigned the new IP contact address.   13. Terminal according to claim 12, characterized in that it comprises a calculation module (MC) arranged to generate each secondary private identifier from said primary private identifier stored in said ISIM type card (IC).   14. Terminal according to claim 12, characterized in that said ISIM type card (IC) is arranged to generate each secondary private identifier from said primary private identifier that it stores.