Telephone call establishing procedure includes checking with server list of available terminals to call, prior to establishing call

The present invention relates to a method for establishing a telephone call between two terminals.

Usually, to establish a telephone communication between two telephones through a telephone network such as the PSTN network (switched telephone network) or the GSM cellular network, one of the telephones calls the other, the network directs the call to the terminal called who, on reception of the call, rings and answers. This method of establishing a telephone call has various drawbacks. One of these drawbacks is that the phone call might disturb the called party. The present invention aims first of all to avoid such a disturbance.

To this end, the invention relates to a method of establishing a telephone call between two terminals through a telephone network, in which

one of the terminals calls a connection server and sends it a request for the purpose of receiving a list of available terminals belonging to a given group;

the server searches a table for the available terminals belonging to said group and transmits the list of available terminals to the calling terminal;

the calling terminal selects one of the terminals from the list in order to get in touch with it through the telephone network.

Thus, the server indicates to the calling terminal the availability status of the terminals of the group, which prevents it from disturbing the called party when the latter is unavailable.

Another drawback of the method of establishing a telephone call of the prior art lies in the fact that the caller must necessarily know the number of the called terminal. The latter can therefore not remain anonymous. The invention also aims to overcome this drawback.

Thus, in a particular embodiment of the invention, the calling terminal notifies the server of the selected terminal, the server searches said table for a telephone call number associated with the selected terminal and puts the calling terminal and the selected terminal in contact. by call transfer.

The server is responsible for connecting the calling terminal with an available terminal, in other words ready to be called, by simple call transfer. Thanks to this, the calling terminal does not need to know the call number of the terminal to be called.

In another embodiment of the invention, the calling terminal directly calls the selected terminal.

In this case and advantageously, the calling terminal having stored a table of corresponding terminals containing, for each corresponding terminal, an identifier and an associated telephone call number, the server transmits to the calling terminal a list of identifiers of available terminals and, automatically, the calling terminal searches its table for the telephone call number associated with the identifier of the selected terminal and calls said number.

As a variant, the server transmits to the calling terminal a list of available terminals containing, for each terminal, an identifier and an associated telephone call number and, automatically, the calling terminal extracts from said list the call number associated with the identifier of the selected terminal and calls said number.

Advantageously, each terminal wishing to receive a call from another terminal of a given group declares itself available from the server for this group. A terminal can belong to different groups and declare itself available for one or more of these groups.

After declaring itself available for a given group, said terminal can declare itself unavailable to the server for said group in order to no longer receive calls from terminals of said group via the server.

After the expiration of a time delay from the moment when the terminal declared itself available for a given group, the server can automatically change said terminal from the available state to the unavailable state for said group. Thanks to this, the terminal does not need to notify the server that it declares itself unavailable. The server can also consult the telephone network in order to determine whether the terminal is reachable or unreachable in order to update its availability status.

The invention also relates to a connection server for implementing the method defined above, comprising means of connection to a telephone network, means of connection to a database intended to store a plurality of tables listing a plurality of groups of terminals with, for each terminal, its state of availability and its telephone call number, database management means, means of communication with a terminal, arranged to receive a request to acquire a list of available terminals belonging to a given group and to send the list of available terminals in response to said request, and call transfer means.

The invention also relates to a terminal for implementing the previously defined method, arranged to communicate through a telephone network, comprising communication setting means arranged to acquire a list of available terminals and to call directly, automatically, a terminal selected from said list.

The invention will be better understood with the aid of the following description of a particular embodiment of the method and of the server of the invention with reference to the appended drawing in which:

- Figure 1 shows a schematic view of two terminals and a connection server;

- Figure 2 a functional block diagram of the server of Figure 1 and

- Figures 3 and 4 show a flowchart of the various steps of the method of the invention.

In FIG. 1, two terminals 1 and 2 have been shown, in this case GSM cellular telephones, a connection server 3, a database 4 and a GSM cellular telephone network 5.

The database 4 stores a plurality of tables respectively associated with a plurality of groups of terminals. The table of a group contains, for each terminal of the group, an identifier, a telephone number, a confidential code and an availability status indication specifying whether the terminal is declared available or unavailable. A group of terminals can be made up of a set of friendly terminals or terminals wishing to participate in a discussion, a voice forum, on a given topic.

The server 3 is intended to put terminals in telephone connection through the network 5. It comprises a module 30 for an interface for connecting to the GSM network 5, a module 31 for connecting to the database 4, a module 32 for management. of the database 4, a module 33 for communication with terminals and a module 34 for call transfer. The module 32 for managing the database 4 is intended to store, delete, modify and consult information in the database 4. In addition, after the expiration of a time delay of a predefined duration, here two hours, from the moment when a terminal listed in the database 4 has declared itself available, the module 32 automatically switches this terminal from the available state to the unavailable state in the database

4. The communication module 33 comprises a speech recognition block and a speech synthesis block allowing the server 3 to communicate vocally with terminals and their users. The call transfer module 34 is intended to perform call transfers in order to connect terminals through the GSM network 5.

The method of establishing a telephone call between the two terminals 1 and 2, through the GSM network 5, will now be described, with reference to FIG. 3.

From the outset, it will be noted that the server 3 and the terminals, with their users, communicate by voice.

In a step 60, a plurality of terminals, and in particular terminals 1 and 2, call the server 3 and register in a group of friendly terminals. When registering, each terminal provides the server 3 with its GSM telephone number, a confidential code and indicates its current state of availability for this group. The server 3 assigns an identifier, here group A, to the group, informs the terminals thereof and stores all the information relating to group A in a specific table of the database 4.

In a step 61, under the control of its user, the terminal 2 wishing to receive calls from other terminals of group A calls the server 3 through the GSM network 5. In a step 62, after establishment of the telephone communication between the terminal 2 and server 3, terminal 2 identifies itself by providing server 3 with the identifier of its group, namely group A, its personal identifier and its confidential code. The server 3 checks the validity of these identification data (group identifier, personal identifier and confidential code), by comparison with those contained in the database 4. If the identification is correct, in a step 63a, the terminal 2 declares itself available from server 3 for group A. Otherwise, server 3 signals terminal 1 that its identification is incorrect and interrupts communication with calling terminal 2, in a step 63b. In a step 64, the server 3 records in the table of group A of the database 4 the indication that the terminal 2 is available. Furthermore, each terminal of group A wishing to receive calls from other terminals of the same group declares itself available from the server 3 for this group A, as has just been explained. Of course, a terminal could belong to different groups and declare different availability states for the different groups.

In a step 65, the terminal 1 calls the server 3 through the GSM network 5. After establishing the communication between the terminal 1 and the server 3, the terminal 1 identifies itself, in a step 66. If the identification is correct, we go to step 67a. Otherwise, we go to step 67b in which the server 3 signals to the terminal 1 that its identification is incorrect then interrupts the communication with the terminal 1.

In step 67a, terminal 1 sends server 3 a request to receive the list of available terminals belonging to group A, terminal 1 thus declaring itself implicitly available for group A. In step 68, server 3 then stores the indication that terminal 1 is available for group A. In a step 69, the server 3 searches the table of group A for the terminals declared available for this group A then, in a step 70, transmits to the calling terminal 1 the list of identifiers of the terminals available in group A. This list contains in particular the identifier of the terminal 2. In a step 71, after having received the list, the terminal 1 selects the terminal 2 therein, under the control of its user, and notifies the server 3 of the selected terminal 2. In a step 72, on receipt of the request, the server 3 searches the table of group A for the telephone call number of the terminal 2 and, in a step 73, proceeds to a call transfer to the terminal 2 in order to connect the two terminals, calling 1 and called 2, through the GSM network 5.

In a step 74a, if the terminal 2 picks up on reception of the transferred call, a telephone communication through the GSM network 5 is established between the two terminals 1 and 2. Otherwise, the call remaining unanswered, the terminal 2 hangs up in a step 74b.

After declaring itself available, a terminal can call server 3 and, after identification, voluntarily declare itself unavailable for group A. Server 3 then changes the terminal in question from the available state to the unavailable state in the base. data 4. In any event, after expiration of a two-hour delay from the moment the terminal declared itself available, the server 3 automatically declares it unavailable for group A by changing the terminal in question from the available state. in the unavailable state in the database 4.

As a variant, the time delay could be eliminated. In order to update the availability status of the terminals, the server 3 could also consult the telephone network in order to determine whether the terminals are reachable or unreachable.

Terminals could belong to different groups and have different availability states for different groups.

It is also possible to connect terminals wishing to discuss a particular topic. In this case, the server offers the calling terminals various discussion topics in order to form discussion groups, or voice forums. These themes can be offered by the terminals themselves. The server could also offer the terminal themes adapted to the place where it is located.

In two variant embodiments of the establishment method of the invention, differing from the method which has just been explained only by what will now be described, after having received the list of available terminals transmitted by the server 3, the terminal 1 directly calls the selected terminal 2, through the telephone network 5.

In the first variant, each terminal 1, 2, subscribed to the connection service of the server 3, comprises an application for establishing telephone communication. This application includes a module for storing a table of corresponding terminals and a call module. The storage module is intended to record in memory a table of corresponding terminals containing, for each corresponding terminal, an identifier and an associated telephone call number. The call module is designed to automatically (that is to say without user intervention) acquire a list of available terminals containing the identifiers of the available terminals, transmitted by the server 3, search for the number of telephone call from a terminal selected by a user from the table of corresponding terminals and call this number directly. During the method of establishing a communication between the two terminals 1 and 2, the server 3 transmits to the calling terminal 1 a list of available terminals containing the identifiers of these terminals, the calling terminal selects therein the identifier of the terminal 2, under the control of its user, and, automatically, searches the corresponding terminal table for the corresponding telephone call number and calls this number directly in order to establish a telephone call with terminal 2.

In the second variant embodiment, the list of available terminals transmitted by the server 3 to the terminal 2 contains, for each terminal, an identifier and a telephone call number. Each terminal 1, 2 subscribed to the connection service includes a connection application capable of acquiring the list of available terminals, extracting therefrom the call number of a terminal selected by the user and calling this number, from automatic way. During the process of establishing a telephone call, the server 3 transmits to the terminal 1 the list of available terminals, the terminal 1 selects a terminal there, under the control of its user, and, automatically, extracts the list from it. telephone number of the selected terminal and calls this number directly.

The terminals could also notify their state of availability to the server 3 by sending a message, for example an SMS, containing identification data of the terminal and the indication that the terminated! is available or unavailable.

Of course, the invention could be applied to any other telephone network.