Method and apparatus for establishing a video telephony session

0001The present invention relates to a method and a device for establishing a videophone session.

0002It also relates to a telephone handset associated with a device to video telephony according to the present invention.

0003The invention lies in the area of ​​video telephony in which the image enriches audio communication between two parties via a telecommunications network.

0004Known audio and video data transfer devices on the same telecommunications network. The exchange of data flow between videophones on a type of telecommunications network Switched Telephone Network (PSTN) allows owners of such videophones to communicate by voice and the picture with their matching if the course has an equivalent terminal.

0005Transferring the image to a PSTN nevertheless requires strong reduction in the quality of the transmitted image. This penalizes the use of such services.

0006In the American patent application published as 2001/0056466 describes a collaborative work session setup system on a computer via an Internet-type network enrichment of telephone call set up on the same telecommunication network.

0007The use of the Internet as a medium of communication Telephone is now widespread and can thus penalizes high use scale of these systems.

0008Are also known videotelephony systems in which the voice is transferred via a first telecommunications network while the image is transmitted over a second telecommunication network.

0009This type of video telephony system penalizes the user of such a system in meaning that it is necessary to establish two simultaneous calls on both networks different telecommunication, thereby increasing the cost of the call billed to the user.

0010In addition, this videophone system requires modification or networks telecommunication and the cost of deployment of such services limited the implementation thereof.

0011The invention aims to solve the drawbacks of the prior art by providing a method and a system for preparing video telephony session in which the user during a conventional audio telephone call by via a PSTN, can enrich its good video data quality while ensuring limited communication cost. The invention also aims to ensure that users of the present invention a good session video calling and without having to change the telecommunications networks used by the present invention.

0012To this end, in a first aspect, the invention provides a method establishment of a videotelephony session between two devices videophone connected via a packet telecommunications network, characterized in that each videophone device is connected to a telephone handset, each telephone handset is connected to a switched telephone network via the videophone device to which it is connected and the method comprises the steps, performed by each videophone device, for detecting an establishment of telephone communication between two telephone handsets by through the switched telephone network, for detecting at least one predetermined command generated from a telephone handsets and establishment of a videophone session between the two devices videophone connected to telephone handsets over the packet telecommunications network.

0013Correspondingly, the invention relates to a device for video telephony establishing a videotelephony session between two devices videophone connected via a packet telecommunications network, characterized in that each videophone device is connected to a telephone handset, each telephone handset is connected to a switched telephone network via the videophone device to which it is connected and that the videophone device comprises detecting means within a telephone communication between the two telephone sets via the telephone network switched, means for detecting at least one predetermined command generated from a telephone handsets and means of establishing a session video telephony between the two devices connected to video telephony handsets telephone to the packet telecommunications network.

0014Thus, when two parties are in communication via a PSTN network, it is possible to establish a session between the videophone subscribers via another telecommunication network ensuring high quality of restitution of the transmitted video images.

0015According to another aspect of the invention, the predetermined command is a predetermined combination of tone dialing signals.

0016Thus, using the tone dialing signal as command to establish a video telephony session between the two corresponding, conventional handsets can be used in the invention.

0017According to another aspect of the invention, each videophone device detects a predetermined command generated from the combined respectively telephone to which it is connected.

0018Thus, video telephony session can be established only if each corresponding wants video telephony session is established. This desire is materialized by generating an institution controlling the videophone session through its Handset.

0019According to another aspect of the invention, video telephony session is performed by via a linking server.

0020According to another aspect of the invention, each videophone device registers with the matchmaking server.

0021According to another aspect of the invention, each device receives a videophone confirmation of its registration with the matchmaking server and generates the less a predetermined message to the handset which is connected.

0022Thus, the call is automatically informed of the possibility of order a videophone session establishment without having to exchange with Remote corresponding information such as the possession of a device video telephony according to the present invention.

0023According to another aspect of the invention, when establishing the telephone communication between two telephone sets, the number of Phone handset called dialed from the handset caller is detected and stored by the video telephony device connected to the handset telephone calling.

0024Thus, the video telephony device calling party has information identifying the called party.

0025According to another aspect of the invention, the stored telephone number is transferred by the videophone device connected to the telephone calling handset by via packet telecommunications network to update server in relationship for determining URI Uniform Resource Identifiers public and / or private corresponding to video telephony device connected to the handset phone called.

0026Thus, and without the intervention of a correspondent, it is possible to determine the address of the remote videophone device and therefore can establish a session video calling on another telecommunication network than the one the communication was initiated.

0027According to another aspect of the invention, the telephone communication between the two telephone sets via the switched telephone network is released when the videophone session on the telecommunication network packets is established between the two devices videophone.

0028Thus, the cost of video telephony session is reduced.

0029The invention also relates to a method for establishing a session video calling video calling between two devices connected via a network packet telecommunication, characterized in that each device videophone is connected to a telephone handset, each handset is connected to a switched telephone network via the device videophone which it is connected and in that the method comprises the steps, carried out each handset determination during communication telephone with a remote handset to handset connection remote telephone to the PSTN through a remote videophone device, recording control of the device videophone to which the telephone handset is connected to a connection server via a packet telecommunications network, information of the user of the handset to the handset connection remote switched telephone network via a device video calling and recording of video telephony device to the server and order to establish a video call session between the device videophone which the handset is connected and video telephony device remote, videotelephony session being established on a telecommunication network by packets.

0030Correlatively, the invention provides a telephone handset to be switched connected to a telephone network via a device video telephony, the telephone handset comprising means for determining when a telephone communication with a remote telephone receiver connection of the remote telephone handset to the telephone switched network via a remote videophone device, control means videophone device registration to which the handset is connected to a connection server via a telecommunications network packet, user information of the resources of the telephone receiver connection of the remote telephone handset to the telephone switched network via a videophone device and recording device video telephony server and control means establishing a session video telephony between the videophone device to which the handset is connected and remote video telephony device, video telephony session being established on a packet telecommunication network.

0031Thus, the call is automatically informed of the possibility of order a videophone session establishment without having to exchange with Remote corresponding information such as the possession of a device video telephony according to the present invention.

0032The invention also relates to computer programs stored on a medium information, said program comprising instructions for carrying implement the processes videophone session set previously described, when loaded and executed by a computer system.

0033The characteristics of the invention mentioned above, as well as other, appear more clearly on reading the following description of an example of embodiment, the description being made in conjunction with the accompanying drawings, which:<sl><li>Fig. 1 represents the architecture of the videophone system according to the present invention;</li><li>Fig. 2 shows a block diagram of a visual telephone apparatus according to present invention;</li><li>Fig. 3 shows the algorithm of establishment of a videophone session performed by a videophone device of a user who made a call telephone to a corresponding according to a first embodiment of the present invention;</li><li>Fig. 4 shows the algorithm of establishment of a videophone session performed by a videophone device of a user having received a call a corresponding telephone according to a first embodiment of the present invention;</li><li>Fig. 5 shows the algorithm of establishment of a videophone session performed by a telephone handset of a user who made a call telephone to a corresponding according to a second embodiment of the present invention;</li><li>Fig. 6 shows the algorithm of establishment of a videophone session performed by a telephone handset a user receiving a call a corresponding telephone according to a second embodiment of the present invention;</li><li>Fig. 7 shows the algorithm of establishment of a videophone session performed by a videophone device of a user who made a call telephone to a corresponding according to a second embodiment of the present invention; </li><li>Fig. 8 shows the algorithm of establishment of a videophone session performed by a videophone device of a user having received a call a corresponding telephone according to a second embodiment of the present invention.</li></sl>

0034Fig. 1 represents the architecture of the videophone system according to the present invention.

0035The videophone system according to the present invention enables two subscribers 10 and 20 in telephone communication via a network Switched Telephone 170 to establish a video call session through a telecommunications packet network 180.

0036The subscriber 10 has a video calling device 100a connected to a network telecommunication packet 180 and the telephone communications network switched PSTN 170.

0037The packet communication network 180 is for example a network Internet type comprising a connection server 185.

0038The contact 185 update server identifies corresponding wishing make a video call session, and when the videophone session is open, plays the role of proxy for video telephony communication devices.

0039In general, a proxy is a server that acts as an interface between a subscriber and another remote node. The proxy forwards the messages generated by the subscriber to the recipient. The recipient replies to the proxy as if it was generating the message. The proxy then forwards the response to the subscriber.

0040The videophone device 100a is also connected to a TV 130a. This connection is done for example through an outlet "scart" allowing the transfer of audio signals and composite video signals and color between the videophone device 100a and 130a TV.

0041The TV 130a is a conventional TV and used according to the present invention as a display means of the received video sequence and processed by the 100a video telephony device.

0042The TV 130a is also used as means of sound reproduction audio messages from the corresponding 20 remote.

0043The videophone 100a of device 120a is connected to a telephone handset. The 120a handset is by example and not limited to a combined DECT telephone wire type. DECT stands for Digital Enhanced Cordless Telephone. The handset is connected to the videophone device 100a through a radio link with a base station 110a DECT.

0044The handset 120a is alternatively a telephone handset © compliant WIFI or Bluetooth ©.

0045© WIFI is the trade name for the IEEE 802.11 standard technology ETSI (European Telecommunications Standards Institute), Bluetooth © is the name commmercial of 802.15 technology, standardized by IEEE (Institute of Electrical and Electronics Engineers).

0046The videophone device 100a, 160a are also associated with a microphone, video camera 150a 140a and at least one speaker. It is noted here that the microphone 160a, 150a and 140a camera speaker can be integrated or not the videophone device 100a.

0047The microphone 160a allows the subscriber 10 can talk to the subscriber 20 when the videophone session is established.

0048The speaker 140a retrieves sound generated messages the subscriber 20 when the videophone session is established.

0049150a allows the camera to capture images that are transferred to the subscriber 20 when video telephony session is established.

0050The subscriber 20 has, as subscriber 10, a videophone device 100b identical to the videophone device 100a connected to telecommunication networks 170 and 180, a TV 130b and 120b a telephone handset connected to the device videophone 100b via a base station 110b.

0051The videophone device 100b is also associated with a microphone 160b, a video camera 150b and 140b at least one speaker.

0052Fig. 2 shows a block diagram of a visual telephone apparatus according to invention.

0053The videophone apparatus 100 is adapted to detect a command predetermined made during a telephone call with a corresponding via the PSTN 170 by the handset user telephone 120 connected to the videophone device 100 to establish a session videoconference between the user and the corresponding via network Internet 180.

0054The videophone device 100 includes a communication bus 201 which are connected a CPU 200, a ROM 202, a RAM 203, receiving means DTMF 209, Acronym of Dual Tone Multi Frequency or touch tone dialing signals, a communication interface with the Internet network 180 and an input interface output 206.

0055The ROM 202 stores among other programs involving out the invention which will be described later with reference to Figs. 3, 4, 7 and 8. The ROM 202 is for example an EEPROM, acronym EEPROM.

0056More generally, the programs according to the present invention are stored in a storage means. This storage medium is readable by a computer or a microprocessor 200. This storage means is integrated or not video telephony device 100, and may be removable.

0057When powering on the videophone device 100, programs according to the present invention are transferred into RAM 203 which contains while the executable code of the invention as well as the necessary data for setting practice of the invention.

0058The microprocessor 200 is for example based on an architecture RISC.

0059The videophone device 100 provides the connection between the base station 110 telephone handset 120 and the PSTN 170 via an interface 210 PSTN network and a base station interface 208.

0060The PSTN interface 210 and base station 208 are interconnected by via DTMF receiving means 209.

0061DTMF signal receiving means 209 is adapted to detect the signal DTMF tone dialing passing between the base station interface 208 and the PSTN 170. These DTMF network are eg the number of Destination phone or a set of predetermined DTMF corresponding to predetermined keys on the telephone handset 120.

0062The receiving means 209 DTMF signals, is in a particular mode achievement, capable of distinguishing the tone dialing signals DTMF predetermined generated via the telephone handset which he is connected to predetermined DTMF tone dialing signals generated through the telephone handset of the remote party.

0063The DTMF signal receiving means 209 will then process in this variation the predetermined DTMF tone dialing signals generated via the telephone handset to which it is connected.

0064The PSTN network interface 210 is a standard interface, known as the Interface name Z. It allows among others to control line seizure or a hook thereof.

0065The PSTN interface 210 is capable of releasing a call established between two parties when video telephony session is established.

0066The PSTN 210 network interface is adapted to generate a current loop between the video telephony device 100 and the base station 110 when the session videophone is established so as to allow the transfer of audio information between the videophone device 100 and the handset 120.

0067The base station interface 208 is in a particular mode of the present invention, connected to coding means 205 audio decoding video.

0068The network interface 207 is an interface for transmitting and receiving information by way of the telecommunication network 180 packets.

0069This interface allows the exchange of messages for establishing a session videophone subscribers between October 2 and 20. It also allows the transfer of audiovisual data when video telephony session is established.

0070The network interface 207 is, in a preferred embodiment, an interface allowing a local network for example of Ethernet communication with computing devices of the subscriber or a communication with a modem example ADSL. ADSL stands for "Asynchronous Digital Subscriber Line. "

0071Alternatively, the network interface 207 comprises an ADSL modem.

0072The input output interface 206 is an interface capable of shaping the signals from the microphone 160 and camera 150 for a transfer thereof to the Party during a videophone session. The input output interface 206 is also able to process and decode the audiovisual signals received during the corresponding a videophone session that they are returned by the speaker 140 or the handset 120 and the TV 130.

0073For this, the input output interface 206 comprises an audio decoder encoder Video 205.

0074The video encoder audio decoder 205 is adapted to decode the received data by via the network interface 180 and to form analog signals 130 transferred to the TV via a SCART connection type and to the least a speaker such as for example the speaker 140.

0075For example, the video encoder audio decoder 205 is adapted to encode and / or decode the data according to the H.263 standard.

0076The video encoder audio decoder 205 is adapted to encode the signals from the microphone 140 and camera 150 in the form of digital signals for that these are transferred to the telecommunication network 180.

0077In an alternative embodiment of the present invention, the encoder-decoder audio video 205 is adapted to decode the audio signals received via the network interface 207 and transmitted to the handset 120. this same variant, the audio from the handset signals are coded 120 by the video encoder audio decoder 205 in the form of digital signals for that these are transferred to the telecommunication network 180.

0078The input output interface 140 further comprises connection means for connecting devices such as recording devices video sequences such as video recorders, image capture devices such as camcorders or digital cameras.

0079Later, when we speak of the elements of the device video calling 100 described above, which shall include an index "a" when these are elements 100a videophone device of the subscriber 10 and an Index "b" when the latter are elements of the videophone device 100b the subscriber 20.

0080Fig. 3 shows the algorithm of establishment of a videophone session performed by a videophone device of a user 10 that do a telephone to a corresponding 20 in a first mode embodiment of the present invention.

0081The processor 200a 100a videophone device reads, from memory Still ROM 102a, the program instructions corresponding to steps E300 E314 of FIG. 3 and loads them into random memory 203a to execute.

0082At step E300, the processor 200a 100a videophone device detects a line plug carried by the base station 110a of the telephone handset 120a of the subscriber 10.

0083This detection is for example done by detecting the appearance of a current Power in the telephone line linking the base station 110a and the switch PSTN network manager 170 telephone subscriber line 10.

0084This detection is performed by the RTC 210 a network interface and is notified to 200a 100a videophone processor device.

0085Upon detecting the occurrence of an electric current in the telephone line connecting the base station 110a and the PSTN network switch 170, the processor 200a proceeds to the next step E301.

0086In the next step E301, the processor 200a controls the receiving means DTMF signals 209a so that it enters into a detection process DTMF tone dialing signals on the link between the interface base station 208a and 210a PSTN network interface.

0087The tone detection is performed for a period predetermined for example of the order of 30 seconds.

0088By that stage, the processor 200a proceeds to step E302 which comprises check whether at least one touch-tone DTMF was detected on the link between the base station interface 208a and 210a PSTN network interface. This corresponds to the dialing a telephone number of a caller.

0089If not, the CPU 200a stops the algorithm returns to step E300 and awaits a new line of plug detection.

0090If so, the processor 200a stored in the RAM 203a equivalents symbols to tone dialing signals DTMF previously detected.

0091These symbols are the telephone number of the correspondent that the subscriber 10 wants to join. This call is for example the subscriber 20.

0092This operation performed, the processor 200 passes to the next step E304.

0093At that step, the processor 200 controls the signal receiving means DTMF 209a so that it enters a signal detection process DTMF tone dialing on the connection between the station interface base 208a and 210a PSTN network interface.

0094At the following step E305, the processor 200a checks whether signal dialing tone corresponding to predetermined symbols been detected.

0095These symbols are predetermined for example and without limitation the sequence of symbols "# *".

0096This detection process of tone dialing signals DTMF consisting of E304 and E305 step is performed as a signal tone dialing corresponding to predetermined symbols have not detected and that for the duration of the telephone call.

0097Upon detection of the tone dialing signals corresponding the predetermined symbols, the processor 200a passes to the following step E306.

0098By dialing 120 on the telephone handset that sequence of symbols predetermined, the subscriber 10 has expressed the wish to move from one communication traditional telephone with his corresponding to a videophone communication.

0099Indeed, in a conventional telephone conservation, correspondents, if they have video telephony devices of the present invention may decide by mutual agreement to switch to video calling on a network of telecommunication permitting substantial transmission rates. This network according to the present invention a DSL network.

0100At step E306, the processor 200 a videophone device performs establishing a videophone session.

0101For this, the CPU 200a controls the transfer via the network interface 207a and the packet communication network 180 a message to the matchmaking server 185.

0102According to a preferred embodiment, the establishment of the session video telephony is performed according to the SIP protocol. SIP Acronym of "Session Initiation Protocol" is described in the recommendation of the IETF RFC 3261.

0103Of course, other protocols may be used in the present invention. These protocols are for example H323 or MGCP acronym for "Gateway to Digital Media Controller Protocols".

0104The message transferred to the step E306 is a message type "Register" compliant with the SIP protocol.

0105The "Register" message is a message to save the device 100a in the video telephony connection server 185. This message includes the address URL and IP address of the video telephony device 100.

0106This is done, the processor 200a expects the next step E307 the reception via the network interface 207a and the network Telecommunications 180 a confirmation message from the update server in 185 relationship.

0107This message is of the "200 OK" when SIP is used.

0108This is done, the control processor 200a to the stage E308 transfer via the network interface 207a and the network telecommunications packet of a message to the update server in 185 relationship of "Invite" message compliant with the SIP protocol.

0109This message includes the telephone number stored previously to the step E303.

0110The contact 185 update server determines from this phone number in E.164 format (CCITT recommendation), the resource identifiers URI uniform public and / or private for the phone number included in the "Invite" message.

0111These uniform resource identifiers are stored in a base data associated with the matchmaking server 185.

0112This is done, the processor 200a expects the next step E309 the reception via the network interface 207a and the network Telecommunications 180 a confirmation message from the update server in 185 relationship.

0113This message is of the "200 OK" when SIP is used.

0114As will be described with reference to Fig. 4, in the connection server 185 performs various tasks prior to the generation of the message confirmation.

0115On receiving the confirmation message, the CPU 200a proceeds to step Next E310.

0116At step E310, the processor 200a enters a reception waiting loop a busy tone generated by the PSTN switch 170 to which the 120a handset is associated. This busy signal corresponds to the release of the telephone line from the subscriber 20 at the step E407 Fig. 4 to be described later.

0117The detection of the busy tone is performed by the receiving means DTMF signals 209a.

0118Upon detection by the means for receiving DTMF tone signals 209a a occupation, 200a processor controls the opening of the telephone line, thus interrupting the telephone call and goes to the next step E311. In Meanwhile, the control processor 200a establishing the PSTN interface 210a a current loop 110a with the base station of the handset telephone 120a.

0119At step E311, the CPU 200a controls the transfer via the network interface 207a and the packet communication network 180 a message to the matchmaking server 185 of an acknowledgment message reception.

0120This acknowledgment message is a message of "SIP ACK" when SIP is used.

0121In an alternative embodiment of the present invention, the processor 200a does not perform the waiting loop of the step E310 and the processor 200a in parallel the transfer of the acknowledgment message, controls the opening of the line telephone and so interrupts the telephone communication and the establishment by the PSTN network interface 210a of a current loop with the base station 110a the handset 120a.

0122This done, the videophone device 100a is then connected to step E312 the videophone device 100b of the corresponding via the matchmaking server 185 which then acts as a proxy.

0123During the videophone session, video signals received from the device videophone remote 100b are decoded and transferred to the television 130a.

0124The audio signals from the remote videophone device 100b are decoded 130a and transferred to the TV and / or the speaker 140a and / or combined telephone 120a.

0125During the session videophone, video signals received from the camera 150a are encoded and transferred to the remote videophone device 100b.

0126Audio signals received from the microphone 160a and / or the telephone handset 120a are decoded and transferred to the remote videophone device 100b.

0127In the next step E313, the processor 200a enters a waiting loop receiving a combination of tone dialing signals DTMF by the receiving means of DTMF signals 209a.

0128This combination of voice frequency signals corresponds for example to tone dialing associated with the symbols "* #" and is representative of the wish of the subscriber 10 to stop the videophone session.

0129Upon detection by the DTMF signal receiving means 209a of a combination of dialing signals DTMF tone, the processor 200a proceeds to the next step E314.

0130Alternatively, the processor 200a between the step E313 in a waiting loop detecting an on-hook of the telephone handset 120a by the subscriber 10.

0131At step E314, the CPU 200a controls the transfer via the network interface 207a and the packet communication network 180 a message to the matchmaking server 185 a message end control videophone session and ends the present algorithm.

0132Fig. 4 shows the algorithm of establishment of a videophone session performed by a videophone device of a user having received a call a corresponding telephone according to a first embodiment of the present invention.

0133The processor 200 of 100b videophone device of the called subscriber 20 reads, in From the ROM 202b 100b videophone device subscriber 20, the program instructions corresponding to steps E400 to E410 of FIG. 4 and load in RAM 203b to execute.

0134At step E400, the processor 200b videophone device 20 detects telephone call signal such as a ringing signal generated by the switch PSTN network 170 which is connected the base station 110b of the telephone handset 120b and an outlet line 110b performed by the base station and the handset 120b telephone subscriber 20.

0135This detection is performed by the PSTN network interface 210b and is notified to 200b processor 100b videophone device.

0136Upon detection of the call signal and decision line, the processor goes 100b at the following step E401.

0137In this step, the processor 200b controls the signal receiving means DTMF 209b so that it enters a signal detection process DTMF tone dialing on the connection between the station interface base 208b and 210b PSTN network interface.

0138In the next step E402, the processor 200b checks whether signal dialing tone corresponding to predetermined symbols been detected.

0139These symbols are predetermined for example and without limitation the sequence of symbols "# *".

0140This detection process of tone dialing signals DTMF consisting of steps E401 and E402 is made until the signal tone dialing corresponding to predetermined symbols have not detected and that for the duration of the telephone call.

0141Upon detection of the tone dialing signals corresponding the predetermined symbols, the processor 200b proceeds to the next step E403.

0142By dialing the telephone handset 120b this sequence of symbols predetermined, the subscriber 20 has expressed the wish to move from one communication traditional telephone with his corresponding to a videophone communication.

0143Indeed, in a conventional telephone conservation, correspondents, if they have video telephony devices of the present invention may decide by mutual agreement to switch to video calling on a network of telecommunication permitting substantial transmission rates. This network according to the present invention a DSL network.

0144At step E403, the processor 200b 100b videophone device performs establishing a videophone session.

0145For this, the CPU 200b controls the transfer via the network 207b and the telecommunications packet network 180 of an interface message to the matchmaking server 185.

0146According to a preferred embodiment, the establishment of the session video telephony is performed according to the SIP protocol.

0147Of course, other protocols may be used in the present invention. These protocols are for example H323 or MGCP acronym for "Gateway to Digital Media Controller Protocols". In this case, the two video telephony devices must still use the same protocol Logon.

0148The forwarded message to the E403 step is a message type "Register" compliant with the SIP protocol.

0149The "Register" message is a message to save the device 100b in the videophone connection server 185. This message includes the address URL and IP address of the videophone device 100b.

0150This is done, the processor 200b expects the next step E404 the reception via the network interface 207b and network Telecommunications 180 a confirmation message from the update server in 185 relationship.

0151This message is of the "200 OK" when SIP is used.

0152This is done, the processor 200b proceeds to the next step E405 and awaits the reception through the network interface 207b and network Telecommunications 180 an invitation message of the update server in 185 relationship.

0153This invitation message has been previously issued by the device 100a video telephony subscriber 10 to the matchmaking server 185 and retransmitted by it at 100b videophone device of the subscriber 20.

0154This is done, the control processor 200b to the next step E406 transfer via the network interface 207b and network Telecommunications 180 a confirmation message to the server linking 185 a confirmation message.

0155This message is of the "200 OK" when SIP is used.

0156This message is then transmitted by the matchmaking server 185 to 100a videophone device of the subscriber 10 and corresponds to the message received step E309 of the algorithm of FIG. 3.

0157This is done, the processor 200b proceeds to step E407 and control the release of the line 120b between the handset and the PSTN 170. Meanwhile, the control processor 200b establishing the PSTN interface 210b of a current loop with the base station 110b of the handset 120b telephone.

0158In the next step E408, the processor 200b waits for the reception by the interface 207b network an acknowledgment message from the matchmaking server 185 a message.

0159This acknowledgment message is a message of "SIP ACK" when SIP is used.

0160This acknowledgment message is the message sent by the device videophone 100a to step E311 to the matchmaking server 185.

0161On receiving this message, the video calling device 100b is then connected to the video telephony device 100a via the provisioning server in 185 relationship which then acts as a proxy.

0162During the videophone session, video signals received from the device videophone remote 100a are decoded and transferred to the TV 130b.

0163The audio signals 100a remote videophone device are decoded 130b and transferred to the TV and / or 140b speaker and / or combined 120b telephone.

0164During the session videophone, video signals received from the camera 150b are encoded and transferred to the remote videophone device 100a.

0165Audio signals received from the microphone 160b and / or the telephone handset 120b are decoded and transferred to the remote videophone device 100a.

0166In the next step E409, the processor 200b enters a waiting loop receiving a combination of tone dialing signals DTMF by the receiving means of DTMF signals 209b.

0167This combination of voice frequency signals corresponds for example to tone dialing associated with the symbols "* #" and is representative of the wish of the subscriber 20 to stop the videophone session.

0168Upon detecting by the signal receiving means of a DTMF 209b combination of dialing signals DTMF tone, the processor 200b proceeds to the next step E410.

0169Alternatively, the processor 200b between the step E409 in a waiting loop detecting an on-hook of the telephone handset 120b by the subscriber 20.

0170At step E410, the processor 200b controls the transfer via the network 207b and the telecommunications packet network 180 of an interface message to the matchmaking server 185 a message end control videophone session and ends the present algorithm.

0171Fig. 5 shows the algorithm of establishment of a videophone session performed by a telephone handset of a user who made a call telephone to a corresponding according to a second embodiment of the present invention.

0172In this embodiment, the handsets of the caller and the call, unlike the first embodiment, are adapted to report to subscribers can switch to a video telephony session when both subscribers have video calling compatible devices.

0173In this second embodiment and example, the subscriber performs 10 a phone call to the subscriber 20.

0174The CPU 120a handset of subscriber 10 reads, from the ROM the handset 120a of the subscriber 10, the instructions program corresponding to steps E500 to E508 of FIG. 5 and the load RAM 120a of the handset to run.

0175At step E500, the processor 120a handset detects a plug the subscriber line 10.

0176In the next step E501, the processor 120a generates handset on the telephone line the tone dialing signals corresponding to the telephone number, in this case the number of the customer's telephone 20.

0177The dialed number, the CPU 120a generates handset the next step E502 message noted A Message to the handset telephone 120b via the PSTN network 170.

0178This message is for example a combination of dialing signals tone or a short message of the SMS type. SMS stands for "Short Message Service".

0179A message is representative of the ownership by the subscriber of a device 10 videophone 100a according to the present invention.

0180This is done, the processor 120a handset passes the step E503 and awaits a response message noted message B combined 120b telephone subscriber 20.

0181This message is for example a combination of dialing signals tone or a short message of the SMS type.

0182The message B is representative of the possession by the subscriber 20 of a device videophone 100b according to the present invention.

0183B if no response message is received within a predetermined time period, the processor 120a handset stops the present algorithm. Indeed, a non-response 120b handset explicitly states that the subscriber B does not have a video telephony device 100b according to the present invention.

0184If the CPU 120a handset receives a response message 120b handset of the subscriber 20, the processor of the handset 120a passes to the following step E504.

0185At this stage, the CPU 120a generates a telephone handset command for generation of tone dialing signals corresponding to a predetermined sequence of symbols such as the sequence of symbols "# *".

0186These tone dialing signals are intended for the device of videophone 100a, as will be explained with reference to Fig. 7.

0187This is done, the processor 120a handset passes the step E505 and awaits a response message noted Message C10 device 120a video telephony.

0188This message is for example a combination of voice frequencies.

0189C10 message is representative of the compatibility and acceptance by the in connection server 185 of the recording device 100a videophone a videophone session.

0190C10 if no response message is received within a time period predetermined, the CPU 120a stops this handset algorithm. Indeed, a non-response videophone device 100a indicates explicitly that the recording of video calling device 100a at a session of video telephony failed.

0191If the CPU 120a handset receives a response message 100a videophone device, the processor passes handset 120a the next step E506.

0192At that step, the processor of the telephone handset 120a control activating a notification means such as for example a diode emitting 120a present on the telephone handset. Of course, Other notifications are also envisaged, such as for example a message voice announcement.

0193This notification is an invitation to switch telephone communication 170 on the PSTN network to a videophone session on the network telecommunication packet 180.

0194This transaction, the processor of the handset passes the following step E507, and waits for a predetermined control by the subscriber 10 through the keyboard 120a handset.

0195This order is for example pressing a predetermined key and representative of the acceptance by the subscriber of the communication 10 tilt telephone current PSTN network 170 to a video telephony session on packet telecommunication network 180.

0196If no command is received within a predetermined time, the CPU 120a handset stops the present algorithm.

0197If an order is received, the processor of the handset 120a passes at the following step E508 and controls the generation of a message in the form of tone dialing signals corresponding to a sequence predetermined symbols.

0198Such tone denoted D10 messages are for the device videophone 100a, as will be explained with reference to Fig. 7.

0199This is done, the CPU 120a stops the handset present algorithm.

0200Fig. 6 shows the algorithm of establishment of a videophone session performed by a telephone handset a user receiving a call a corresponding telephone according to a second embodiment of the present invention.

0201The processor 120b of handset of subscriber 20 reads, from the ROM 120b of the handset of the subscriber 20, the instructions program corresponding to steps E600 to E607 of FIG. 6 and the load RAM 120b of handset to run.

0202At step E600, the processor 120b handset detects a signal call generated by the PSTN switch 170 which is connected the station 1 base 10b of the handset 120b and line seizure by the subscriber 20.

0203This transaction, the processor of the handset 120b passes the step E601 and awaits receipt of a message from the handset 120a the subscriber 10.

0204This message is for example a combination of dialing signals tone or a short message of the SMS type.

0205This message is the message A as described in reference to step E502 of the Fig. 5. A message is representative of the ownership by the subscriber 10 a videophone device 100a according to the present invention.

0206A no message is received within a predetermined time, the Processor 120b handset stops the present algorithm. Indeed, no message explicitly states that the subscriber does not have a videophone device 100a according to the present invention.

0207If the processor 120b handset receives a message from A 120a telephone handset of the subscriber 10, the processor of the telephone handset 120b proceeds to the next step E602.

0208At step E602, the processor generates a telephone handset 120b reply message recorded message B to the 120a Handset the subscriber 10.

0209This message is for example a combination of dialing signals tone or a short message of the SMS type.

0210The message B is representative of the possession by the subscriber 20 of a device videophone 100b according to the present invention.

0211This operation performed, the processor 120b handset passes the next step E603.

0212In this step, the processor 120b generates a telephone handset command for generation of tone dialing signals corresponding to a predetermined sequence of symbols such as the sequence of symbols "# *".

0213These tone dialing signals are intended for the device of videophone 100b, as will be explained with reference to Fig. 8.

0214This transaction, the processor of the handset 120b passes the step E604 and awaits a response message noted Message C20 of the device videophone 120b.

0215This message is for example a combination of dialing signals tone.

0216C20 message is representative of the compatibility and acceptance by the in connection server 185 of the recording device 100b videophone a videophone session.

0217C20 if no response message is received within a time period predetermined, the CPU 120b stops this handset algorithm. Indeed, a non-response videophone device 100b indicates explicitly that the recording of video calling device 100b to a session video telephony failed.

0218If the processor 120b handset receives a response message 100b videophone device, the processor passes handset 120a the next step E605.

0219At this stage, the telephone handset 120b control processor activating a notification means such as for example a diode emitting 120b present on the handset.

0220This notification is an invitation to switch telephone communication 170 on the PSTN network to a videophone session on the network telecommunication packet 180.

0221This transaction, the processor of the handset 120b passes the next step E606 and waits for a predetermined control by the subscriber 20 via keyboard 120b handset.

0222This order is for example pressing a predetermined key and representative of the acceptance by the subscriber of the communication 20 tilt telephone current PSTN network 170 to a video telephony session on packet telecommunication network 180.

0223If no command is received within a predetermined time, the Processor 120b handset stops the present algorithm.

0224If a command is received, the processor 120b handset password at the following step E607 and controls the generation of a message in the form of tone dialing signals corresponding to a sequence predetermined symbols.

0225These dialing signals tone, recorded messages D20 are for the videophone device 100b, as will be explained later with reference to Fig. 8.

0226This transaction, the processor of the handset 120b stops present algorithm.

0227Fig. 7 shows the algorithm of establishment of a videophone session performed by a videophone device of a user who made a call telephone to a corresponding according to a second embodiment of the present invention.

0228In this second embodiment and example, the subscriber performs 10 a phone call to the subscriber 20.

0229The processor 200a 100a videophone device reads, from memory Still ROM 102a, the program instructions corresponding to steps E700 to E716 of FIG. 7 and loads them into random memory 203a to execute.

0230Steps E700 to E704 are identical to steps E300 E304 of FIG. 3, those will not be described further.

0231At step E705, the processor 200a checks whether dialing signals voice frequencies corresponding to predetermined symbols were detected.

0232These symbols are predetermined for example and without limitation the sequence of symbols "# *".

0233Upon detection of the tone dialing signals corresponding the predetermined symbols, the CPU 200a proceeds to the next step E706.

0234These tone dialing signals were generated automatically by the processor of the telephone handset 120a to step E504 of Fig. 5 described earlier.

0235At step E706, the processor 200a videophone 10 controller transfer via the network interface 207a and the network telecommunications packet of a message to the update server in 185 relationship.

0236According to a preferred embodiment, the establishment of the session video telephony is performed according to the SIP protocol.

0237Of course, other protocols may be used in the present invention. These protocols are for example H323 or MGCP acronym for "Gateway to Digital Media Controller Protocols".

0238The message transferred to the step E706 is a message type "Register" compliant with the SIP protocol.

0239The "Register" message is a message to save the device 100a in the video telephony connection server 185. This message includes the address URL and IP address of the videophone device 100a.

0240This is done, the processor 200a expects the next step E707 the reception via the network interface 207a and the network Telecommunications 180 a confirmation message from the update server in 185 relationship.

0241This message is of the "200 OK" when SIP is used.

0242If no message is received, the matchmaking server 185 has not accepted recording the video telephony device 100a to a video telephony session and 200a processor stops the present algorithm.

0243If a registration confirmation message is received, the processor 200a goes to the next step E708.

0244At step E708, the processor 200a controls the transfer of a voice message the destination handset 120a via the network interface RTC 210.

0245This message, denoted C10 message is representative of the compatibility and acceptance by the matchmaking server 185 to the device registration 00a 1 videophone to videophone session.

0246The C10 message is for example formed of a series of signals DTMF tone dialing.

0247This is done, the CPU 200a proceeds to the next step E709.

0248In this step, the processor 200a checks for a predetermined period of time receiving a message denoted D10 generated by the telephone handset 120a.

0249D10 if no response message is received within a time period predetermined, the processor 200a stops the present algorithm.

0250Indeed, a non-response of the telephone handset 120a explicitly indicates 10 that the subscriber does not want the current phone call on PSTN network 170 is switched to a videophone session on the network telecommunication packet 180.

0251If the processor 200a receives a message noted D10 handset 120a, the processor 200 passes to the next step E710.

0252Steps E710 to E716 are identical to steps E308 to E314 of FIG. 3, those will not be described further.

0253When the E716 step is performed, the CPU 200a stops this algorithm.

0254Fig. 8 shows the algorithm of establishment of a videophone session performed by a videophone device of a user having received a call a corresponding telephone according to a second embodiment of the present invention.

0255The processor 200b 100b videophone device called subscriber 20 reads, from the ROM 202b of the videophone device 100b the subscriber 20, the program instructions corresponding to steps E400 to E410 Fig. 4 and load in RAM 203b to execute.

0256The steps E800 and E801 are identical to steps E400 and E401 of FIG. 4, they shall not be described further.

0257At step E802, the processor 200b checks whether dialing signals voice frequencies corresponding to predetermined symbols were detected.

0258These symbols are predetermined for example and without limitation the sequence of symbols "# *".

0259These tone dialing signals were generated automatically by the processor 120b E603 handset in step Fig. 6 described earlier.

0260Upon detection of the tone dialing signals corresponding the predetermined symbols, the processor 200b proceeds to the next step E803.

0261At step E803, the processor 200b videophone 20 controller transfer via the network interface 207b and network telecommunications packet of a message to the update server in 185 relationship.

0262According to a preferred embodiment, the establishment of the session video telephony is performed according to the SIP protocol.

0263Of course, other protocols may be used in the present invention. These protocols are for example the H323 protocol or protocol MGCP.

0264The message transferred to the step E306 is a message type "Register" compliant with the SIP protocol.

0265The "Register" message is a message to save the device 100b in the videophone connection server 185. This message includes the address URL and IP address of the videophone device 100b.

0266This is done, the processor 200b expects the next step E804 the reception via the network interface 207b and network Telecommunications 180 a confirmation message from the update server in 185 relationship.

0267This message is of the "200 OK" when SIP is used.

0268If no message is received, the matchmaking server 185 has not accepted recording the video telephony device 100b in a video telephony session and 200b processor stops the present algorithm.

0269If a registration confirmation message is received, the processor 200b goes to the next step E805.

0270At step E805, the processor 200b controls the transfer of a voice message the destination handset 120b via the network interface RTC 210.

0271This message, denoted C20 message is representative of the compatibility and acceptance by the matchmaking server 185 to the device registration 100b videophone to videophone session.

0272The C20 message is for example formed of a series of signals DTMF tone dialing.

0273This is done, the processor 200b proceeds to the next step E806.

0274In this step, the processor checks 200b for a predetermined period of time receiving a message denoted D20 generated by the telephone handset 120b.

0275D20 if no response message is received within a time period predetermined, the processor 200b stops the present algorithm. Indeed, a non response 120b handset explicitly states that the subscriber does 20 not wish the current telephone call on the PSTN 170 or tilted to a video telephony session over the telecommunication network 180 packets.

0276If the processor 200b receives a message noted D20 handset 120b, 200b processor goes to the next step E807.

0277Steps E807 to E812 are identical to steps E405 to E410 of FIG. 4, they shall not be described further.

0278When the E812 step is performed, the CPU 200b stops this algorithm.

0279Of course, the present invention is not limited to the embodiments embodiments described herein, but encompasses, on the contrary, any variant within the scope of the skilled person.