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

[0001] The invention relates to multimedia services, such as dialogue services, instant messengers or broadcasts of audiovisual programs, available both on a mobile terminal, such as a mobile telephone, digital personal assistant (PDA) communicating, smartphone, etc., and on stationary devices such as a PC, TV etc.

[0002] It particularly relates to the switching options offered to the user in a mobility situation to optimize the tracking of multimedia sessions initiated outdoors ("outdoor") from a mobile terminal via a mobile communication network (e.g. via GSM, GPRS, UMTS, I- WLAN, etc.), when it accesses the home environment ("indoor") containing one or more stationary devices capable of supporting multimedia sessions in progress.

[0003] Currently, manufacturers of telecommunications devices are proposing several solutions for connecting services and networks using fixed and mobile networks, called "fixed-mobile connections", which are being developed commercially by telecommunications operators.

[0004] However, manufacturers' solutions are not always allowed by standardization bodies (such as 3GPP ("Third Generation Partnership Project") for mobile networks or ETSI TISPAN for fixed networks), becoming then called "proprietary" solutions, i.e. limited to enriched multimedia services appropriate for the terminal provided by the manufacturer, which do not allow the use of ordinary services, such as an instant messenger session with content sharing among several users when the environment is not fully compatible with the manufacturer's solution.

[0005] In addition, applicable mobile communication standards (see in particular 3GPP TS 23.228 V6.4.1 (2004-01), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; IP Multimedia Subsystem (IMS); Stage 2 (Release

6) >>), propose stationary-mobile connection with support for user mobility, based on the IMS ("IP Multimedia Subsystem") architecture specific to the mobile network, this IMS architecture is reused and adapted (by ETSI TISPAN) to take into account specificity of fixed networks. However, the fixed-mobile connection approach considered in current mobile communication standards (3GPP) only provides for the case when the user moves from the external environment to the home environment, still using the same terminal.

[0006] Current solutions, whether proprietary or resulting from specifications, allow in the best case a user (entering a home environment equipped with a local fixed network and having an active multimedia session in progress on their mobile terminal) to continue their multimedia session on the local fixed network home environment, instead of in the mobile network in which it was previously initiated, but always with the same terminal. Fixed-mobile connection is made only at the level of information transfer, with the user's session no longer running through the mobile communication network, but via the fixed-line network as soon as the user is connected to the local home network.

[0007] Therefore, none of the solutions currently proposed take into account home devices available in the local home network to offer the user optimized switching solutions, especially in terms of cost, ergonomics, resources, etc. However, a user approaching the local home network may want to switch their or their multimedia sessions in progress to one or more local home network devices more suited to one or several networks.

Object and concise description of the invention [0008] The invention proposes a solution enabling a mobile terminal user to use, for one or several multimedia sessions in progress on his mobile terminal, resources available in a home environment when he enters the local network of this environment.

[0009] To this end, the invention relates to a method of switching a multimedia session from a mobile terminal connected to a mobile communication network to at least one home device connected to a local home network, further comprising a home gate, the mobile terminal and the home gate being connected to the user system through which multimedia sessions are established, and the method comprises the step of establishing at least a first multimedia session between the mobile terminal and the user system via a mobile communication network characterized in that it further comprises the following steps:

a) detecting the vicinity of the local home network by a mobile terminal,

b) selecting one or several home devices capable of handling the first multimedia session in progress on the mobile terminal,

c) approval from the mobile terminal of at least one home device from among the selected devices,

d) establishing a second multimedia session between the approved home device and the application system. The method according to the invention allows the user entering the home environment to switch his ongoing multimedia session on his mobile terminal to the home device of the local network. In this way, with an interrupt or not (e.g. perceived by the user) of the service provided by the multimedia session in progress, the user can use the potential opportunities offered by devices available in the local home network, choosing the equipment most suited to the session (the ability to process data, display, sound, etc.). In addition, it can also benefit from reduced communication costs by using services over a fixed network rather than a mobile network.

[0011] As for the operator with whom the user initiated a multimedia session from his mobile terminal, the method according to the invention allows him to ensure the loyalty of his clientele by proposing new innovative services that are at the user's disposal, regardless of the access network used. The operator can also provide its users with service continuity, regardless of the environment in which they are located (external or home) and, as a consequence, retain their customers throughout the duration of the multimedia session.

[0012] According to an embodiment of the invention, the method further comprises, after step a) and before step b), step a1) transmitting, via the mobile terminal to the home gateway of the local home network, data related to the establishment of the first multimedia session in progress on the mobile terminal. In this way, the home gateway will be able to select, in step b), the home device or devices, depending on this data and the ability of home devices connected to the local home network to support the first multimedia session. In a given case, if the capacities of the available home terminals are at least equivalent to those of the mobile terminal, a second multimedia session between the user system and the home terminal can be established.

[0013] According to another embodiment of the invention, the home gateway records regularly or in response to the reception of data related to the restoration of the first multimedia session, at least the capabilities of home devices connected to the local home network, which allows the user to be offered a switch, a list of adapted devices that are actually available in the moment.

[0014] During step d), a second multimedia session may be established in response to a request to establish a multimedia session sent by the mobile terminal to the user system or in response to a request to establish a multimedia session sent by the home gateway.

[0015] In the first case, the data related to the establishment of the second multimedia session between the approved home device and the user system is sent through the home gateway to the mobile terminal. The user can thus control the switching moment by activating it, for example, only when it is physically present in front of the selected home appliance.

[0016] The invention also relates to a mobile terminal comprising means for detecting the radio signal of an access station to a local home network, the local home network comprising one or several devices connected to the home gate and means for exchanging data with the gate via radio communication with the access station ê pu, characterized in that it also has the means to respond to the detection of a radio signal, send to the home gate information related to the establishment of a multimedia session in progress between the mobile terminal and the user system.

[0017] Using such a mobile terminal, the user can switch his multimedia session in progress to the home device of the local network, and as a consequence, benefit from the continuity of service without having to track the session on his mobile terminal when he enters the home environment .

[0018] According to an embodiment of the invention, the mobile terminal further comprises means for displaying a list of home devices sent through the home gateway and means for selecting at least one home appliance from this list. The user can thus choose the home device on which he intends to track his multimedia session.

[0019] The mobile terminal may further comprise means for transmitting a request to establish a new multimedia session between the selected device or home devices and the user system, the request being based on information related to establishing a multimedia session in progress between the mobile terminal and the user system. In this case, the user decides when to switch.

[0020] The invention also relates to a computer program product downloaded from a communication network and / or stored on a computer readable medium and / or executed by a microprocessor of the mobile terminal described above, wherein the program includes program code instructions for transmission in response to radio signal detection. , to the home gate of information related to the establishment of a multimedia session in progress between the mobile terminal and the user system.

[0021] The computer program product further includes instructions for displaying a list of home devices sent by the home gateway and means for selecting at least one home device from this list.

[0022] The computer program product may further include instructions for sending a request to establish a new multimedia session between the selected device or home devices and the user system, the request being based on information related to the establishment of a multimedia session in progress, between the mobile terminal and the user system.

[0023] This program may be stored on a recording medium.

[0024] The invention also relates to a home gateway connected to several home devices in a local home network, characterized in that it comprises means for recording at least the capacity of home devices connected to the local home network and for determining a list of home devices capable of handling a media session in progress between depending on the stored capacity and data related to the establishment of a multimedia session in progress.

[0025] Thanks to the home gateway according to the invention, dynamic control of the devices of the local home network is performed, which allows continuous knowledge of the capabilities of the local home network actually available.

[0026] According to an embodiment of the invention, the gateway further comprises means for transmitting a request to establish a new multimedia session between the at least one home device and the user system, the request being based on information related to the establishment of a multimedia session in progress between the mobile terminal and the user system.

[0027] The invention finally relates to a computer program product downloaded from a communication network and / or stored on a computer-readable medium and / or executed by a home gate microprocessor as described above, characterized in that it includes instructions for recording at least the capabilities of home devices connected to network and for determining the list of home devices capable of supporting a multimedia session in progress, between the mobile terminal and the user system, depending on the saved capabilities and data related to the establishment of a multimedia session in progress.

[0028] The computer program product may further include program code instructions for transmitting a request to establish a new multimedia session between at least one home device and the user system, said request being based on information related to the establishment of a multimedia session in progress between the mobile terminal and the user system .

[0029] This program may be stored on a recording medium.

[0030] Document EP-1622315 describes a system and method for performing multimedia session switching from a mobile terminal between a mobile communication network and a home network.

Brief Description of the Drawings [0031] Other features and advantages of the invention will result from the following description of individual embodiments of the invention, given as non-limiting examples, with reference to the accompanying drawings, in which:

- figure 1 is a schematic overall view of a system according to an embodiment of the invention,

- figure 2 shows the ordering of steps implemented in the method of switching multimedia sessions, according to an embodiment of the invention,

- figure 3 shows the ordering of steps implemented in the method of switching multimedia sessions, according to another embodiment of the invention.

Detailed description of embodiments of the invention [0032] The invention is intended to enable switching of one or several multimedia sessions from a mobile terminal connected to a mobile communication network to one or several home devices belonging to the local home network.

[0033] A multimedia session is defined as any period of continuous communication during which the user has access to one or more media, such as voice, text, image, video or other, by means of a terminal. For example, a multimedia session may correspond to an ordinary telephone conversation, television communication, broadcasting of an audiovisual program, conversation on an Internet messenger, etc.

[0034] Figure 1 shows an overall view of the system according to the invention, according to an embodiment of the invention. Elements that are involved in using the method of switching multimedia sessions according to the invention according to the system of Fig. 1, are user 1 equipped with mobile terminal 2 (e.g. mobile telephone, personal digital assistant PDA, smartphone, etc.), home environment 10 (e.g. apartment, public place (station, airport, restaurant ...)) containing several home appliances such as landline phone 11, PC 12, television 13 and radio 14, home gate 15 ("Home Gateway") and at least radio station 16 (for example WiFi ™ station), whose radio signal covers the home radio zone 160, and the utility system 20. Landline telephone 11, PC 12, television 13, radio 14, radio station 16 and home gate 15, to which the latter are connected, form a local home network 150. Fig. 1 it is believed that the external environment corresponds to the entire space outside the home radio zone 160.

[0035] The user system 20, which can be implemented on a remote server, is intended to control the establishment and tracking of all 5 multimedia sessions related to a user on his mobile terminal (an initiated session or a session intended for the user, such as in the case of an intended user session ). The user system 20 may, for example, be an IP Multimedia or IMS ("IP Multimedia Subsystem") subdomain system, which is a known standardized architecture for NGN ("Next Generation Networking") networks for telephony operators and which allows the provision of fixed and mobile multimedia services . This system uses voice technology in the IP ("Internet Protocol") network based on the implementation of the 3GPP ("3rd Generation Partnership Project") standardized SIP ("Session Initiation Protocol") operating with the standard IP protocol. The IMS architecture is compatible with existing telephone systems and allows users to use multimedia services both when traveling in an external environment (roaming situation) and in the home environment. To this end, the IMS architecture uses standard IP protocols specified by IETF ("Internet Engineering Task Force"). In this way, a multimedia session, regardless of whether it takes place between two users in the IMS architecture, between one IMS user and an Internet user, or between two Internet users, is established using exactly the same protocol. Service deployment interfaces are also based on IP protocols.

[0036] The architecture of the IMS system, the individual units of such a system, the registration of user devices in the IMS system, as well as the establishment of a multimedia session in the IMS system are namely described in detail in document EP 1 560 368 (or US 11/046 480), in document << 3GPP TS 23.228 V6.4.1 (2004-01), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; IP

Multimedia Subsystem (IMS); Stage 2 (Release 6) >>, available at the Internet address<a href="http://www.3QDD.ora/ftp/specs/archive/23_series/23.228/,_i_w_dokumencie_RPC3261_grupyroboczej_IETF_(grupa_robocza_w_sieci_internetowej,_lub_Internet_Engineering_Task_Force),dost%c4%99pnym_pod_adresem_internetowym_http://www.ietf.ora/rfc">http: //www.3QDD.ora/ftp/specs/archive/23 series / 23.228 /, and in the RPC3261 document of the IETF working group (working group on the Internet, or Internet Engineering Task Force), available at http: // www.ietf.ora / rfc</a>.

[0037] The connection between the user system 20 and the mobile terminal 2 is provided by means of the mobile communication network 21 (e.g. GSM, GPRS, UMTS, IWLAN networks, etc.), while the connection between the user system 30 and the home gate 15 is made via using fixed-line communications networks 22 (e.g. RTC, xDSL, HFC, FTTH networks, etc.).

[0038] Home gateway 15 is an interface between a wide area network, such as fixed-line communications network 22 (WAN interface "Wide Area Network") and a local network, such as local home network 150 (LAN interface "Local Area Network"). It is the focal point of all media streams: telephone, data, video systems, images, music ... In a known way a home gate, such as France's Livebox ™ home gate

Telecom ™, provides control of all home devices via wired or radio connections (for example, WiFi ™ connection) to broadcast to one or more of these devices, media streams entering the local home network. An example of such a home gate is namely described in detail in WO

2005/112365.

[0039] According to the invention, the home gateway 15 further includes specific functions that enable it to know in real time the resources of home devices of the local network, so as to propose one or more home devices capable of supporting a multimedia session in progress on the user's mobile terminal for switching when the latter enters the home radio zone 160. To this end, the home gateway 15 can update a fixed table for management and knowledge of the local network 150, including in particular the presence of home devices connected to the local home network, IP addresses allocated to these devices, the properties of multimedia sessions in progress in the local home network as well as the packing algorithms used / unpacking or "CoDecs" (for example, CoDec M-JPEG). Permanent management of the table is not mandatory, the home gateway can also determine this information immediately when necessary. The home gateway is also capable of exchanging data with the mobile terminal 2 via radio station 16, namely to send to the mobile terminal a list of home devices capable of operating a multimedia session in progress to the mobile terminal and to receive the device or home devices selected from the list via the terminal mobile. These functions are built into the home gateway in the form of IT instructions.

[0040] Furthermore, before placing this service, the mobile terminal is provided with means capable of performing matching (or adaptation) with the radio station 16 forming the radio access point of the home gate 15, in order to detect the home radio zone 160. To this end, recognition by the terminal mobile 2 networks forming a home radio zone 160. For example, in the case of a home radio zone created by the WiFi ™ field, the mobile terminal will be able to recognize the WiFi ™ network identifier (SSID) that is transmitted periodically by the access point (radio station 16). According to the invention, the mobile terminal 2 comprises a client application or software for supervising the reception of a radio network identifier corresponding to a home radio zone. Detection of the home radio zone 160 by the mobile terminal is carried out in a known manner according to the protocols and rules defined by the type of connection used (e.g. WiFi ™). The general rule is that mobile terminal 2 is in the listening position (detection mode) of the radio signal broadcast by the access point created by the radio station 16.

[0041] In addition, in the case of WiFi ™ networks, the level of matching security between the mobile terminal and the radio access point of the home radio zone can be increased by using WEP ("Wired Equivalent Privacy") and WPA ("WiFi ™ Protected Access" ), corresponding to the well-known security protocols specified in the IEEE 802.11 standard and the IEEE 802.11i standard, respectively.

[0042] A method of switching a multimedia session according to an embodiment of the invention which is used in the system of Fig. 1 will now be described with reference to Fig. 2.

[0043] For simplicity, a situation will be considered here where:

- there is only one radio access point to the home radio zone 160: radio station 16,

- user 1 has only one multimedia session A in progress during switching,

- switching takes place only on the home appliance of the local home network 150.

[0044] In the embodiment described with reference to Fig. 2, the multimedia session switching is started by the user's mobile terminal towards the user system. The service considered here, which is the subject of a multimedia session, is a dialogue service, such as chat via an instant messenger ("chat") between two users.

[0045] At the beginning (step S1), the user 1 connects to the mobile communication network 21 in an external environment ("outdoor" situation), that is, he gains access to this network in the space outside the home radio zone 160. The mobile communications network can be, for example, the well-known UMTS (Universal Mobile Telecommunication System) network to which the mobile terminal has access by connecting to its operator's GPRS (SGSN node), such as specified in the method described in TS 33.102 ("Security architecture"). The HLR database ("Home Location Register"), which stores user network profile data, generates validation vectors for the SGSN node, and then mutual validation between the terminal and the SGSN node is performed.

[0046] After connecting to the mobile communication network 21, user 1 registers with the user system 20 (step S2). More precisely, to be able to access multimedia services that user 1 has subscribed to with his operator, user 1 registers with IMS, which is the creator (selected here for the example) of the user system. Connection to IMS is made by registering the user using the SIP "Register" method as specified in RFC 3261 specified by IETF. One of the data used as a parameter is the user's public identity, which is used to identify this user to external users (the user may have several public identities). Registering the user in the user system 20 allows him to receive, in particular, requests for establishing multimedia sessions initiated by external users (independently from a fixed or mobile network), such as a request to establish a dialogue session ("chat") for example.

[0047] User 1 then performs a request to establish a multimedia session A between its mobile terminal 2 and the user system 20 (step S3). In a known manner, user 1 sends a "INVITE" call from his terminal (method described in RFC

3261) to establish this multimedia session. Important data corresponding to the parameters of this call are:

- the public identity of the calling user and that belonging to his interlocutor, in the case of a dialogue service,

- the "contact" parameter, which allows the network to rout information related to the session (signaling and media data) to the terminals used by users at the session in question,

- characteristics of the medium chosen by the caller for this session, namely: type of medium (voice, image), quality of services required, in particular by defining codecs for activated media, presentation of the IP address of the terminal and broadcast ports and reception for the media used.

[0048] All these parameters are described in the SDP ("Session Description Protocol" part described in RFC 2327) of the "INVITE" method. Before establishing this session, there are negotiations of medium parameters between individual users. The establishment of a multimedia session manifests itself at the mobile network level through a resource reservation mechanism. In the UMTS mobile network, this resource reservation corresponds to the activation of "PDP Context" ("Racket Data Protocol Context") between the terminal and GGSN ("Gateway GPRS support Node") of the operator for medium transfer, thus providing a guarantee of service quality for a multimedia session.

[0049] The user 1 then moves in the external environment towards the home environment 10. When the user enters the home zone 160, his mobile terminal 2 immediately detects the radio station 16 of the radio signal covering the home radio zone (step S4). Indeed, the mobile terminal simultaneously tracks several signaling channels (also called control broadcasting channels) of the network that surround it. It is therefore able to detect and signal its entry into the home radio zone (WiFi ™ SSID identification). Depending on the implementation case, WEP and WPA security protocols or keys may be used for mobile terminal authentication.

[0050] After the connection to radio station 16 has been established, terminal 2 is connected to the local home network 150 (step S5). This connection is made thanks to the known DHCP ("Dynamic Host Control Protocol") function, which allows the home gateway (router) to assign an IP address to the mobile terminal 2 entering the local home network.

[0051] The mobile terminal 2 then transmits information related to the establishment of the multimedia session in progress of the user, through its interface with the home gateway 15 (step S6) (i.e. data / parameters necessary to play the multimedia session in progress). This information especially corresponds to the type of session (as the type of medium chosen) and the adopted network resources (such as codecs and bandwidth used). According to the selected implementation, the transmission of this information can be started either by a request from the home gateway after the mobile terminal is detected (connection) or directly by the mobile terminal if it has been programmed in this way as a result of its connection to the local home network.

[0052] In the next step (step S7), the home gateway 15 analyzes, depending on the information related to the multimedia session in progress transmitted by the mobile terminal, the context of the local home network for determining the switching possibilities that can be proposed to the user, i.e. determines home furnishings that can undertake the proper transmission of a multimedia session in progress to the mobile terminal 2. This analysis takes into account parameters such as, for example, the availability of home devices connected to the gateway, user rights to ready-to-switch devices, the capabilities of home devices such as codecs installed on the latter, as well as the available frequency response. The purpose of the analysis is to determine, depending on the multimedia session in progress on the mobile terminal, home furnishings to receive the correct transmission of the session.

[0053] After analysis, a list of local home network devices 150 is proposed to user 1 via his mobile terminal 2 (displaying the list on the terminal), together, possibly, with a selection of parameters related to e.g. codecs and frequency response (high resolution or not) which will be allocated to the second multimedia session B (i.e. the one that will take place on the home device after switching) (step S8).

[0054] Based on the proposed list, the user selects a home device (e.g. PC 12) from the local home network 150, from which his multimedia session will continue after switching, and information corresponding to the selected device is forwarded to the home gateway 15 (step S9) .

[0055] If the switch is refused, the switch method stops and the user continues his session in a manner previously established on his mobile terminal. This means that the user's multimedia session is transferred to the mobile communications network 21.

[0056] If switching to one of the proposed home appliances is allowed, the method according to the invention proceeds as detailed below.

[0057] The parameters considered for switching are considered and transmitted by the home gateway 15 to mobile terminal 2 (step S10). These parameters correspond to:

- the user's public identity, which remains unchanged during this switching,

- the "Contact" parameter, which is changed so that the information is no longer routed to the mobile terminal, but to the terminal selected by the user during step S9. This "Contact" parameter, specified in RFC 3261, can have the following syntax: <sp: username @ home_IP_section_of_selected_home>

- media properties resulting from context analysis during stage S7. These properties are saved in the SDP ("Session Description Protocol") fields. The Terminal IP address, as well as the transmit and receive ports for the media used, correspond to those from the home device selected in the local home network.

[0058] These parameters are transmitted by the home gateway 15 to terminal 2 using a protocol supported by the radio interface between the mobile terminal and the home gateway from which the terminal is selected. For example, for Bluetooth ™ technology, the Bluetooth ™ CTP ("Cordless Telephony Profile") protocol could be used, and for Wifi ™ technology, 802.11b (/ g) could be used, implemented in France Telecom ™ LiveBox ™.

[0059] The transfer of these parameters between the home gateway and the mobile terminal can also be done during the previous step S8.

[0060] However, these parameters are transmitted at this stage of the method (step S10) rather than during step S8, because it avoids sending information regarding the whole of the candidate home appliances, while only some of them will be selected if the user tries for switching during step S9. In addition, at this stage it is possible to remove the correlation of information from the network level (selection of home devices) with information from the utility level (information necessary to establish multimedia sessions). After selecting the terminal to switch (step S9), the local home network lowers the parameters necessary for the user system to prepare the session switch to the home device selected as a result of the mobile terminal approval (see later step S11).

[0061] The mobile terminal 2 sends a switch request to the user system 20 (step S11). The request contains all the parameters necessary for switching mentioned above.

[0062] When the switch request is received by the user system 20, the operator checks the compliance of the request with the user service profile. Then, the user system 20 prepares the transmission of multimedia session A (initial session on the mobile terminal in an external environment) to the multimedia session (session established to the home device selected in the local home network) (step S12).

[0063] If the network resources required for multimedia session B on the fixed network 22 and at the level of the local home network 150 are no longer available before switching for the service in question, these resources are allocated (step S13).

[0064] Optionally, the user system may make a notification confirming the end of multimedia session A by the user (step S14). Depending on the possibility of providing services, the user system may leave the user's choice to specify the end of multimedia session A in progress. From a user's point of view, this measure may allow in some cases non-off-stream transmission, such as when the session of a retransmitted match to its mobile terminal is turned off only when it is actually in front of its TV (home device previously selected).

[0065] The user system ends the user's multimedia session A (step S15).

[0066] Network resources that were allocated to multimedia session A are released at the mobile network level 21 (step S16). Similarly, the resources of the correspondent network connected to user 1 during the multimedia session are also released.

[0067] At this point, user 1 has his multimedia session B on the selected home device in the local home network 150.

[0068] Multimedia session B runs until the end of the connection.

[0069] The implementation of the multimedia session switching method according to another embodiment of the invention in the system of Fig. 1 will now be described with reference to Fig. 3. This implementation described on the basis of Fig. 3 differs from that previously described on Fig. 2 in that the multimedia session switching is no longer initiated by the user's mobile terminal, but by the home gateway of the local home network to the user system.

[0070] As before, it is considered that:

- there is only one radio access point to the home radio zone 160: radio station 16,

- user 1 has only one multimedia session A in progress during switching,

- switching is only carried out to one home appliance from the local home network 150.

[0071] The service that is the subject of the multimedia session is a dialogue service, such as chat via two messengers between two users.

[0072] Steps S11 to S19 correspond to steps S1 to S9, previously described with reference to Fig. 2. For simplicity, steps S11 to S19 will not be described here again and we will refer to the description of steps S1 to S9 previously made.

[0073] As a reminder, during step S19, user 1 sends from his mobile terminal 2 a home device (e.g. PC 12) of the local home network 150, which he has chosen to switch his multimedia session, wherein information corresponding to the selected device is forwarded to the home gateway 15 .

[0074] In this embodiment of the method of the invention, the home gateway 15 sends a request to switch the multimedia session to the selected home device (step S20). To this end, the home gateway 15 initiates a new multimedia session B, generating a new "INVITE" request (method described in RFC 3261) which contains parameters resulting from context analysis. This new "INVITE" request allows the user to maintain connectivity (i.e. multimedia session A) with your correspondent until step S23 is turned on to end session A. The parameters required for switching are:

- the user's public identity, which remains unchanged during switching,

- the "Contact" parameter is changed so that it no longer routes information to the mobile terminal, but to the terminal selected by the user during the previous step 19. This "Contact" parameter, specified in RFC 3261, can have the following syntax:

<sip: username @ IP_address_ of the selected home appliance>

- in SDP fields: the characteristics of the medium or media whose required codecs, terminal IP address and broadcast and receive ports for the media used correspond to the selected device of the local home network.

[0075] The following steps S21 to S25 correspond to the individual steps S12 to S16 previously described with reference to Fig. 2 and to which reference will be made for simplicity. The only difference is that in step S21 (corresponding to step S12 previously described in Fig. 2), preparing the transmission of multimedia session A (initial session on the mobile terminal in an external environment) to multimedia session B (session established for the home device selected in the local home network), is performed by the user system 20 in response to the switching request, which is here sent via home gateway 15 of local home network 150.

[0076] By allowing the switching of media sessions in progress on the user's mobile terminal to one or more home network devices, the invention provides many advantages to both the user and the operator.

[0077] At the operator level, the invention allows namely:

o reduce its subscriber loss ("churn") among its clients by offering new innovative services that are available to the user regardless of the access network used.

o optimize the operational costs of mobile network services that can be sent to fixed networks at a low cost, o ensure the continuity of the service allowing the operator to retain his client throughout the entire duration of the extended session.

[0078] At the user level, the invention allows namely:

o for having the continuity of the service enabling the client to extend his session at his entrance to the local home network, to reduce his costs of using the services by accessing them via a fixed rather than a mobile network, to create new applications, by the possibility of choosing different devices, o easier to manage their mobility, regardless of the network used (whether in "indoor" or "outdoor" situations).

[0079] The invention can be used in various 3GPP mobile communications networks, in various types of fixed communications networks and with all types of IMS-like utility systems.

Prepared and verified

Grażyna Palka

Patent Attorney