Switching of multimedia sessions of a mobile terminal to an equipment of a local home network

0001BASCULEM ENT OF SESSI ONS MULTI MEDI AS OF A TERM I NAL MOBI LE ON AN EQUI PEM ENT OF A LOCAL NETWORK

DOM ESTI THAT

0003Field of invention and prior art

0004The present invention relates to multimedia services, such as conversational services, instant messaging or broadcasting of audiovisual programs, which are accessible both on a mobile terminal, such as for example a mobile phone, a communicating personal digital assistant (PDA). , SmartPhone, etc., and on fixed equipment such as a PC, television, etc. It relates more particularly to the switching possibilities offered to a user on the move in order to optimize the monitoring of multimedia sessions initiated outdoors ("outdoors") from the mobile terminal via a mobile communication network (for example via the GSM network, GPRS, UMTS, I -WLAN, etc.) when the latter accesses a domestic environment ("indoor") comprising one or more fixed equipment capable of supporting the multimedia sessions in progress.

0005Several solutions for converging services and networks from fixed and mobile networks, called "fixed-mobile convergence", are now offered by telecommunications equipment manufacturers and are starting to be commercially deployed by telecommunications operators.

0006However, the solutions of equipment manufacturers are not always retained by standardization organizations (such as 3GPP ("Third Generation Partnership Project") for mobile networks or ETSI TI SPAN for fixed networks) and therefore remain so-called solutions " owners ", that is to say solutions limited to enriched multimedia services specific to the terminal provided by the equipment manufacturer and which do not allow the use of simple services such as an instant messaging session with sharing of content between several users when the environment is not entirely compatible with the supplier's solution.

0007In addition, the mobile communication standards in force (see in particular document 3GPP TS 23.228 V6.4.1 (2004-01), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; IP Multimedia Subsystem (I MS); Stage 2 (Release 6)>>) offer a fixed-mobile convergence with support for user mobility by relying on an I MS architecture ("IP Multimedia Subsystem") specific to the mobile network, this I MS architecture being reused and adapted (by I¹ETSI TI SPAN) to take into account the specificities of fixed networks. However, the fixed-mobile convergence approach envisaged in current mobile communication standards (3GPP) only considers the case where the user moves from an outside environment to a domestic environment, always using the same terminal.

0008Current solutions, whether proprietary or from specifications, allow a user (entering a domestic environment equipped with a fixed local network and having a multimedia session in progress on his mobile terminal) to continue his multimedia session on the fixed local network of the home environment instead of the mobile network on which it was previously initiated but always with the same terminal. Fixed-mobile convergence occurs only at the level of the information transport network, the user's session no longer passing through the mobile communication network but through the fixed network as soon as the user is attached to the home local network.

0009Consequently, none of the solutions currently proposed takes into account the domestic equipment available in a local local network to offer the user optimized failover solutions, particularly in terms of cost, ergonomics, resources, etc. However, a user approaching a home local network may wish to transfer his or her current multimedia session (s) to one or more items of equipment in the home local network more suited to the session (s). Object and brief description of the invention

0010The present invention provides a solution allowing a user of a mobile terminal to benefit, for the multimedia session or sessions in progress on his mobile terminal, from the resources available in a domestic environment when he enters the local network of this environment. To this end, the invention relates to a method for switching multimedia session of a mobile terminal connected to a mobile communication network on at least one household equipment connected to a local home network further comprising a domestic gateway, the mobile terminal and the domestic gateway being in connection with an application system by which multimedia sessions are established, said method comprising a step of establishing at least a first multimedia session between the mobile terminal and the application system via the mobile communication network, characterized in that it further comprises the following steps:

0011a) detection of the proximity of the local home network by the mobile terminal, b) selection of one or more domestic devices able to support the first multimedia session in progress on the mobile terminal, c) validation from the mobile terminal of at least one domestic item of equipment selected, d) establishment of a second multimedia session between the validated domestic item of equipment and the application system, e) closure of the first multimedia session. The method of the invention allows a user entering a domestic environment to switch his current multimedia session on his mobile terminal to domestic equipment on the local network. Thus, with or without interruption of service (ie perceptible by the user) provided through the current multimedia session, the user can take advantage of the potential offered by the equipment available in the home local network by choosing the equipment best suited for the session (data processing capacities , display, sound, etc.). In addition, it can also benefit from a reduction in communication costs by using services via a fixed network rather than a mobile network.

0012For the operator with whom the user initiated the multimedia session from his mobile terminal, the method of the invention allows him to build customer loyalty by offering new innovative services which are available to the user regardless of the access network used. The operator can also provide its users with continuity of service regardless of the environment in which they find themselves (outdoor or domestic) and, consequently, keep its customers for the duration of the multimedia session.

0013According to one aspect of the invention, the method further comprises, after step a) and before step b), a step ai) of sending, by the mobile terminal to the home gateway of the home local area network, data relating to the establishment of the first multimedia session in progress on the mobile terminal. Thus, the domestic gateway will be able to select, in step b), the domestic equipment or items of equipment as a function of this data and of the capacities of the domestic equipment connected to the domestic local area network to support the first multimedia session. If necessary, if the capacities of the available domestic terminals are at least equivalent to those of the mobile terminal, a second multimedia session may be defined between the application system and the domestic terminal.

0014According to another aspect of the invention, the home gateway identifies, regularly or in response to the reception of the data relating to the restoration of the first multimedia session, at least the capacities of the household equipment connected to the home local area network, which makes it possible to propose to the user for the changeover a list of suitable equipment which is actually available at this moment.

0015In step d), the second multimedia session can be established in response to a multimedia session establishment request sent by the mobile terminal to the application system or in response to a multimedia session establishment request sent by the home gateway .

0016In the first case, data relating to the establishment of the second multimedia session between the validated domestic equipment and the application system are sent by the domestic gateway to the mobile terminal. The user can thus control the moment of the switchover by not triggering it, for example, only when he is physically present in front of the chosen domestic equipment.

0017The present invention also relates to a mobile terminal comprising means for detecting the radio field of an access point of a domestic local area network, said domestic local area network comprising one or more domestic items of equipment connected to a domestic gateway and means for exchanging data with said gateway via a radio link with the access terminal, characterized in that it further comprises means for, in response to the detection of the radio field, send to said home gateway information relating to the establishment of a multimedia session in progress between said mobile terminal and an application system.

0018With such a mobile terminal, the user can switch his current multimedia session to domestic equipment on the local network and, consequently, benefit from continuity of service without being obliged to continue the session on his mobile terminal when he enters. in a domestic environment.

0019According to one aspect of the invention, the mobile terminal further comprises means for displaying a list of domestic equipment sent by the domestic gateway and means for selecting at least one domestic equipment from said list. The user can thus choose the domestic equipment on which he wishes to continue his multimedia session. The mobile terminal may further comprise means for sending a request for the establishment of a new multimedia session between the selected domestic appliance or devices and the application system, said request being based on the information relating to the establishment of the multimedia session. in progress between the mobile terminal and the application system. In this case, the user decides when to switch. The invention also relates to a computer program product downloadable from a communication network and / or stored on a computer-readable medium and / or executable by a microprocessor of the mobile terminal described above, the program comprising code code instructions. program for, in response to detection of the radio field, send to said home gateway information relating to the establishment of a multimedia session in progress between said mobile terminal and an application system.

0020The computer program product further comprises instructions for displaying a list of household equipment sent by the domestic gateway and means for selecting at least one household equipment from said list.

0021The computer program product may further comprise instructions for sending a request for the establishment of a new multimedia session between the selected domestic appliance or devices and the application system, said request being based on the information relating to the establishment of the multimedia session in progress between the mobile terminal and the application system.

0022This program can be stored on a recording medium. The invention also relates to a home gateway in connection with a plurality of home equipment in a home local network, characterized in that it comprises means for identifying at least the capacities of household equipment connected to said local home network and for determining a list of household equipment able to support a multimedia session in progress between a mobile terminal and an application system in function said capacities listed and data relating to the establishment of the current multimedia session.

0023Thanks to the home gateway according to the invention, dynamic management of the equipment of the home local area network is carried out, which makes it possible to constantly know the capacities of the home local area network actually available.

0024According to one aspect of the invention, the gateway further comprises means for sending a request for the establishment of a new multimedia session between at least one household appliance and the application system, said request being based on information relating to the restoration of the multimedia session in progress between said mobile terminal and the application system.

0025Finally, the invention relates to a computer program product downloadable from a communication network and / or stored on a computer-readable medium and / or executable by a microprocessor of the domestic gateway described above, characterized in that it comprises instructions for identifying at least the capacities of household equipment connected to the network and for determining a list of household equipment able to support a multimedia session in progress between a mobile terminal and an application system as a function of said capacities and data relating to the reestablishment of the current multimedia session.

0026The computer program product may further include program code instructions for sending a request to establish a new multimedia session between at least one home appliance and the application system, said request being based on information relating to the establishment of the multimedia session in progress between the mobile terminal and the application system. This program can be stored on a recording medium.

0027Brief description of the designs

0028Other characteristics and advantages of the invention will emerge from the following description of particular embodiments of the invention, given by way of nonlimiting examples, with reference to the appended drawings, in which: FIG. 1 is a global schematic view of a system in accordance with an embodiment of the invention, FIG. 2 illustrates the sequence of steps implemented in a method for switching multimedia sessions in accordance with an embodiment of the invention, FIG. 3 illustrates the sequence of steps implemented in a method for switching multimedia sessions in accordance with another embodiment of the invention.

0029Detailed description of the embodiments of the invention

0030The invention is intended to allow the switching of one or more multimedia sessions of a mobile terminal connected to a mobile telecommunication network on one or more domestic equipment belonging to a domestic local area network.

0031By multimedia session is meant any period of continuous communication during which a user accesses one or more media, such as voice, text, image, video or the like, from a terminal. For example, a multimedia session can correspond to a simple telephone conversation, a video communication, the broadcasting of an audiovisual program, a conversation on instant messaging, etc.

0032Figure 1 is an overall view of a system of the invention in accordance with an embodiment of the invention. The elements which intervene during the implementation of the method for switching multimedia sessions of the invention in the system of FIG. 1 are a user 1 equipped with a mobile terminal 2 (for example mobile phone, personal digital assistant PDA, smartphone, etc.), a domestic environment 10 (for example a dwelling, a public place (station, airport, restaurant, etc.)) comprising a plurality of domestic equipment such as a landline telephone 11, a PC computer 12, a television set 13 and an audio player 14, a domestic gateway 15 ("Home Gateway") and at least one radio terminal 16 (for example a Wi Fi ™ terminal) whose radio field covers a domestic radio zone 160, and a application system 20. The landline telephone 11, the PC computer 12, the television set 13, the audio player 14, the radio terminal 16 and the home gateway 15 to which the latter are connected form a local home network 150. In FIG. 1, it is considered that the external environment corresponds to all the space situated outside the domestic radio zone 160

0033The application system 20 which can be implemented on a remote server is intended to manage the establishment and monitoring of all multimedia sessions concerning the user on his mobile terminal (session initiated or session intended for the user as in the case of an incoming session intended for the user). The application system 20 can for example be a system from the IP Multimedia or I MS (“IP Multimedia Subsystem”) sub-domain which is a known architecture standardized for next generation NGN networks (“Next Generation Networking”) for operators of telephony and which provides fixed and mobile multimedia services. This system uses voice over IP network technology ("I nternet Protocol") based on a 3GPP ("3rd Generation Partnership Project") implementation standardized by SI P ("Session I nitiation Protocol") operating on a standard I P. L protocol. I MS architecture supports existing telephone systems and allows users to use multimedia services both on the move in an outdoor environment ("roaming" situation) and from a domestic environment. To this end, the I MS architecture uses standard IP protocols, defined by the I ETF ("Internet Engineering Task Force"). Thus, a multimedia session, whether carried out between two users under I MS architecture, between an I MS user and an Internet user, or even between two Internet users, is established using exactly the same protocol. The service development interfaces are also based on the I P protocols.

0034The architecture of an I MS system, the different entities of such a system, the registration of user equipment with an I MS system as well as the establishment of a multimedia session in an I MS system are notably described in detail in document EP 1 560 368 (or US 11/046 480), in the document <<3GPP TS 23.228 V6.4.1 (2004-01), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; IP Multimedia Subsystem (I MS); Stage 2 (Release 6) >>, available at I nternet http://www.3gpp.org/ftp/specs/archlve/23 series / 23.228 /, and in document RFC3261 of the working group I ETF ( working group on the I nternet network, or I nternet Engineering Task Force), available at I nternet <img file="WO2008009838A2_D0001.tif" />

0035The connection between the application system 20 and the mobile terminal 2 is provided via a mobile communication network 21 (for example via the GSM, GPRS, UMTS, I -WLAN network, etc.) while the connection between the application system 20 and the home gateway 15 is done via a fixed communication network 22 (for example via a PSTN, xDSL, HFC, FTTH network, etc.).

0036The home gateway 15 is the interface between a wide area network such as the fixed communication network 22 (WAN "Wide Area Network" interface) and a local network such as the home local network 150 (LAN interface "Local Area Network"). It is the focal point of all media flows: telephone, data, videos, images, music ... In a known manner, the domestic gateway, such as for example the Livebox ™ domestic gateway of the company France Telecom ™, ensures the control of all the household equipment by wire or radio links (for example a Wi Fi ™ link) for broadcasting on one or more of these devices of the media streams entering the local home network. An example of such a domestic gateway is in particular described in detail in document WO 2005/112365.

0037In accordance with the invention, the home gateway 15 further includes specific functionalities enabling it to know in real time the resources of home equipment of the local network so as to propose one or more home equipment able to support the multimedia session in progress on the the user's mobile terminal for switching when the latter enters the home radio zone 160. To this end, the home gateway 15 can maintain a permanent table for the management and knowledge of the home local network 150 which notably includes the presence of home equipment connected to the home local network, the IP addresses assigned to this equipment, the characteristics multimedia sessions in progress in the local home network as well as the compression / decompression or "CoDecs" algorithms used (for example the CoDec M-JPEG). The permanent management of a table is not compulsory, the domestic gateway can also establish this information instantly when necessary. The domestic gateway is also able to exchange data with the mobile terminal 2 via the radio terminal 16, in particular to transmit to the mobile terminal a list of household equipment able to support the multimedia session in progress on the mobile terminal and to receive the domestic equipment selected in this list from the mobile terminal. These functionalities are integrated into the domestic gateway in the form of computer instructions.

0038In addition, prior to the establishment of this service, the mobile terminal is provided with means capable of pairing (or association) with the radio terminal 16 forming the radio access point of the domestic gateway 15, this in order to detect the domestic radio zone 160. To this end, there will be recognition by the mobile terminal 2 of the network forming the domestic radio zone 160. In the case for example of a domestic radio zone formed by a Wi Fi ™ field, the mobile terminal will be able to locate the identifier of the WiFi ™ network (SSI D) which is periodically broadcast by the access point (the terminal radio 16). The mobile terminal 2 comprises, in accordance with the invention, an application or client software for monitoring the reception of the identifier of the radio network corresponding to the domestic radio zone. The detection of the home radio zone 160 by the mobile terminal is done, in a known manner, according to the protocols and principles defined by the type of link that is used (eg Wi Fi ™). The general principle being that the mobile terminal 2 is in the listening position (detection mode) of a radio signal emitted by the access point constituted by the radio terminal 16.

0039Furthermore, in the case of a Wi Fi ™ network, the security level of the pairing between the mobile terminal and the access point to the radio network of the home radio zone can be increased by the use of WEP keys. ("Wired Equivalent Privacy") and WPA ("Wi Fi ™ Protected Access") corresponding to well-known security protocols defined respectively in the I EEE 802.1 1 standard and in the I EEE 802.11 i standard.

0040A method of multimedia session switching according to an embodiment of the invention which is implemented in the system of FIG. 1 will now be described in relation to FIG. 2.

0041For reasons of simplification, we will only consider here the situation where: - there is only one radio access point to the domestic radio zone

0042160: radio terminal 16,

0043- user 1 has only one multimedia session A in progress during the switchover,

0044- the changeover is only made on domestic equipment of the local local network 150.

0045In the implementation described in connection with FIG. 2, the switching of the multimedia session is triggered by the user's mobile terminal to the application system. The service considered here as being the subject of the multimedia session is a conversational service such as a conversation by instant messaging ("chat") between two users.

0046At the start (step S1), the user 1 connects to the mobile communication network 21 in an external environment ("outdoor" situation), that is to say that he accesses said network in a space located outside the domestic radio zone 160. The mobile communication network can for example be a well-known UMTS network ("Universal Mobile Telecommunications System") which the mobile terminal accesses by attaching to a GPRS support node (SGSN node) of its operator as specified by the procedure described in specification TS 33.102 ("Security architecture"). The HLR (Home Location Register) database which stores the data of the user's network profile generates the authentication vectors at the SGSN node, mutual authentication between the terminal and the SGSN node being then carried out.

0047After having connected to the mobile communication network 21, the user 1 registers with the application system 20 (step S2). More precisely, in order to be able to have access to the multimedia services to which user 1 has subscribed to his operator, user 1 registers with the I MS which is the instantiation (chosen here for example) of the application system. The attachment to the I MS is done by registering the user via the SI P "Register" method as defined in RFC 3261 specified by the I ETF. One of the data used as a parameter is the public identity of the user which is used to identify this user with third-party users (the user can have several public identities). The registration of the user in the application system 20 allows him to receive in particular requests for the establishment of multimedia sessions initiated by third-party users (either from a fixed or mobile network) such as a request for the establishment of 'a conversational session ("chat") for example.

0048The user 1 then makes a request to establish a multimedia session A between his mobile terminal 2 and the application system 20 (step S3). In a known manner, user 1 sends from his terminal an "I NVITE" request (method described in RFC 3261) to establish this multimedia session. The important data corresponding to the parameters of this request are: - the public identity of the calling user and that of his interlocutor called in the case of a conversational service,

0049- the "contact" parameter which allows the network to route information relating to the session (signaling and media data) to the terminals used by users for the session in question,

0050- the characteristics of the media desired by the caller for this session, namely: the type of media (voice, image), the quality of service desired via, in particular, the definition of CoDecs for activated media, the presentation of the IP address of the terminal and sending and receiving ports for the media (s) used.

0051All of these parameters are described in the SDP ("Session Description Protocol" - defined in RFC 2327) section of the "I NVITE" method. Before establishing this session, there is negotiation of the media parameters between the different users. The establishment of the multimedia session is reflected in the mobile network by a resource reservation mechanism. In a UMTS mobile network, this reservation of resources corresponds to the activation of the "PDP Context" ("Packet Data Protocol Context") between the terminal and the operator's GGSN ("Gateway GPRS support Node") for the transfer of the media thus ensuring a quality of service guarantee for the multimedia session.

0052The user 1 then moves in the external environment in the direction of the domestic environment 10. When the user enters the domestic radio zone 160, his mobile terminal 2 immediately detects the radio terminal 16 transmitting the radio field covering the zone home radio (step S4). In fact, the mobile terminal simultaneously scans several signaling channels (also called beacon channels) of the networks which surround it. It is therefore capable of detecting and signaling its entry into the domestic radio zone (identification of the WiFi ™ SSI D network). Depending on the implementation cases, there may be use of WEP and WPA protocols or security keys for authentication of the mobile terminal.

0053Once the connection has been established with the radio terminal 16, the terminal 2 is attached to the local home network 150 (step S5). This connection is made thanks to the known function DHCP ("Dynamic Host Control Protocol") which allows the home gateway 15 (router) to assign an IP address to the mobile terminal 2 entering the local home network.

0054The mobile terminal 2 then sends the information relating to the establishment of the current multimedia session of the user through its interface with the home gateway 15 (step S6) (that is to say the data / parameters necessary for reproduce the current multimedia session). This information corresponds in particular to the type of session (such as the type of media selected) and to the negotiated network resources (such as the CoDecs and the bandwidth used). Depending on the implementation chosen, the sending of this information can be triggered either by a request from the domestic gateway after detecting the mobile terminal (attachment), or by the mobile terminal directly if it has been programmed in this way following its connection to the local home network. In the next step (step S7), the home gateway 15 analyzes, as a function of the information relating to the current multimedia session transmitted by the mobile terminal, the context of the home local network to define the switching possibilities that can be offered to the user. user, that is to say determines the household equipment capable of correctly handling the transfer of the multimedia session in progress on the mobile terminal 2. This analysis takes into account parameters, such as the availability of household equipment connected to the gateway, the rights of the user for the equipment candidates for failover, the capacity of household equipment such as the CoDecs implemented on them, as well as the bandwidth available. The purpose of the analysis is to establish, according to the multimedia session in progress on the mobile terminal, the domestic equipment likely to correctly receive the transfer of the session. Once the analysis has been carried out, the list of equipment (s) of the local home network 150 candidate (s) is proposed to the user 1 via his mobile terminal 2 (display of the list on the terminal), with , possibly, a choice of parameters relating for example to the CoDecs and to the bandwidth (high definition or not) which will be allocated to the second multimedia session B (that is to say the one which will take place on a domestic device after tilting) (step S8).

0055From the proposed list, the user selects the home equipment (for example the PC computer 12) of the home local area network 150 from which his multimedia session will be continued after the switching and the information corresponding to the selected equipment. is communicated to the home gateway 15 (step S9).

0056In the event of refusal of switching, the switching process stops and the user continues his session as previously established on his mobile terminal. This means that the user's multimedia session remains transported over the mobile communication network 21.

0057In the event of acceptance of switching over to one of the household appliances proposed, the process of the invention continues as detailed below.

0058The parameters to be considered for the switchover are taken into account and transmitted by the home gateway 15 to the mobile terminal 2 (step S10). These parameters correspond to:

0059- the public identity of the user which remains unchanged during this changeover,

0060- the "Contact" parameter which is modified so as to no longer route the information to the mobile terminal but to the terminal selected by the user during step S9. This "Contact" parameter, defined in RFC 3261, can have the following syntax: <sip: user_name @ IP_address_of_domestic_selected_selected> - the characteristics of the media (s) resulting from the context analysis during step S7 . These characteristics are entered in the SDP ("Session Description Protocol") fields. The terminal IP address as well as the send and receive ports for the media (s) used correspond to those of the domestic equipment selected in the local home network.

0061These parameters are transmitted by the home gateway 15 to the mobile terminal 2 using a protocol supported by the radio interface between the mobile terminal and the home gateway from which the terminal is paired. For example, for Bluetooth ™ technology, the Bluetooth ™ CTP protocol ("Cordless Telephony Profile") could be used, or, for Wifi ™ technology, the 802.11 b (/ g) protocol, implemented on the company's LiveBox ™ France Telecom ™, could be used.

0062The sending of these parameters between the home gateway and the mobile terminal can also be carried out during the previous step SB.

0063However, these parameters are preferably transmitted at this stage of the process (step S10) rather than during step S8 since this makes it possible in particular to avoid sending information concerning all of the candidate household equipment when only some will be choose if the user requests the switchover in step S9. In addition, at this stage, it is possible to decorrelate the network level information (choice of domestic equipment (s)) from the application level information (information necessary for establishing multimedia sessions). Once the selection of the terminal for the switchover has been made (step S9), the local home network lowers the parameters necessary for the application system to prepare the switchover of the session to the chosen domestic equipment following the validation of the mobile terminal (cf. subsequent step S11). The mobile terminal 2 sends a switchover request to the application system 20 (step S11). All the parameters necessary for the switchover mentioned above are present in the request.

0064Upon receipt of the changeover request by the application system 20, the operator checks the conformity of the request with the service profile of the user. Then, the application system 20 prepares the transfer of the multimedia session A (initial session on the mobile terminal in an external environment) to the multimedia session B (session established towards the domestic equipment chosen in the domestic local network) (step S12).

0065If the network resources required for the multimedia session B in the fixed network 22 and at the level of the local home network 150 are not already available before the switchover for the service in question, there is allocation of these resources (step S13). Optionally, the application system can perform a notification for confirmation of the end of the multimedia session A by the user (step S14). According to the possibilities of service implementation, the application system can leave the user the choice to determine the end of his current multimedia session A. From a point of view of the user, this means can allow in certain cases the transfer without interruption like, for example, by cutting the session of a match broadcast on his mobile terminal only when he is actually in front of his television set (domestic equipment chosen beforehand). The application system ends the user's multimedia session A

0066(step S15).

0067The network resources which were allocated for the multimedia session A are released at the mobile network 21 (step S16). Likewise, the resources of the correspondent's network in connection with the user 1 in the multimedia session A are also released.

0068At this time, the user 1 has his multimedia session B on the selected household equipment of the home local network 150.

0069Multimedia session B continues until the end of the call. We will now describe in relation to FIG. 3 an implementation of a multimedia session switching method according to another embodiment of the invention which is implemented in the system of FIG. 1. This implementation described in FIG. 3 differs from that described previously in FIG. 2 in that the switching of the multimedia session is triggered, no longer by the user's mobile terminal, but by the home gateway of the home local area network. to the application system.

0070As before, we consider here that: - there is only one radio access point to the domestic radio zone

0071160: radio terminal 16,

0072- user 1 has only one multimedia session A in progress during the switchover,

0073- the changeover is only made on domestic equipment of the local local network 150.

0074The service that is the subject of the multimedia session is a conversational service such as an instant messaging conversation ("chat") between two users.

0075The steps S11 to S19 correspond respectively to the steps S1 to S9 described previously in relation to FIG. 2. For the sake of simplification, the steps S11 to S19 will not be described again here and we will refer to the description of the steps S1 to S9 made previously.

0076As a reminder, during step S19 the user 1 sends from his mobile terminal 2 the domestic equipment (for example the computer PC 12) of the domestic local area network 150 which he has selected for switching his session multimedia, the information corresponding to the selected equipment being communicated to the home gateway 15. In this embodiment of the method of the invention, it is the home gateway 15 which invokes the request to switch from the multimedia session to the selected home equipment (step S20). To this end, the home gateway 15 initiates a new multimedia session B by generating a new request "I NVITE" (method described in RFC 3261) which integrates the parameters resulting from the analysis of the context. This new request "I NVITE" allows the user to maintain communication (that is to say multimedia session A) with his correspondent as long as step S23 is not triggered to end session A. parameters considered for failover are:

0077- the public identity of the user which remains unchanged during this changeover,

0078the "Contact" parameter is modified so as to no longer route the information to the mobile terminal but to the terminal selected by the user during the previous step S19. This "contact" parameter, defined in RFC 3261, can have the following syntax:

0079<sip: username @ IP_address_of_domestic_selected_> - in the SDP fields: characteristics of the media (s) including the desired CoDecs, terminal IP address and the send and receive ports for the media (s) used corresponding to the equipment selected from the local home network. The following steps S21 to S25 respectively correspond to the steps S12 to S16 described previously in relation to FIG. 2 and to which we will refer for the sake of simplification. The only difference is that in step S21 (corresponding to step S12 previously described with FIG. 2), the preparation of the transfer from the multimedia session A (initial session on the mobile terminal in an external environment) to the multimedia session B (session established towards the domestic equipment chosen in the domestic local network) is carried out by the application system 20 in response to the switching request which is sent here by the home gateway 15 of the home local network 150.

0080By enabling the switchover of the multimedia session or sessions in progress on the user's mobile terminal to one or more items of equipment on a home network, the present invention provides both the user and the operator with numerous advantages. . At the operator level, the invention allows in particular: o to reduce its rate of loss of subscribers ("churn") in its customers by proposing new innovative services which are made available to the user whatever the access network used, o to optimize the operational costs for the mobile network services which can be transported over fixed networks at lower cost, o allow continuity of service ensuring the operator retains his client for the entire duration of the extended session.

0081At the user level, the invention makes it possible in particular: o to have continuity of service ensuring the customer to extend their session when they enter the local home network, o to reduce their costs of using services by accessing via a fixed rather than mobile network, o creating new uses through the possibility of choosing a variety of equipment, o managing mobility more easily regardless of the network used (whether in an "indoor" or "outdoor" situation ).

0082The present invention can be implemented on different 3GPP mobile communication networks, on any type of fixed communication network and with any type of application system similar to I 'MS.