Mobile telephone telecommunications network having server centre with address assembly authorising service access and permanent connection posts set providing confidential network server centre managed between assembly posts.

Telecommunications network and method for placing telecommunications stations in communication via such a network.

The present invention relates to the field of telecommunications and, in particular, to the field of mobile or wired telephony.

More particularly, the invention relates to a public network with permanent connection capable of offering subscribers a service having functionalities identical to those of a private radio network.

As will be appreciated, the invention thus finds application in many fields. Particularly interesting applications are found in fields in which mobile workers can be reached at all times when they are on the move. Fleets of vehicles used in public transport, taxis, ambulances, etc. may thus be affected by such a service.

As is known, the use of a private radio network has two major drawbacks.

First of all, a private radio network requires the setting up by the user of a hardware infrastructure that is relatively heavy and expensive to maintain.

In addition, the use of such a network requires reserving a portion of radio spectrum with an authorized body.

Finally, the stations used with such private radio networks are specific to these networks and require an adaptation period on the part of the users.

Also, the object of the invention is to provide a telecommunications network and a telecommunications method via such a public network having functionalities similar to those of a private radio service but without exhibiting the drawbacks thereof.

Thus, according to the invention, a telecommunications network is proposed, of the type comprising permanent connection links with telecommunications stations of said network.

According to a general characteristic of this network, it comprises a server center in which are loaded a set of addresses of a part of said telecommunications stations which are authorized to access a service of permanent connection of said stations so as to creating a restricted and confidential network between these stations, the server center further comprising means for managing links established between the stations of said set.

This creates a virtual network with a closed structure in which stations can communicate with each other. When a telecommunications network of the mobile type is used and when one assigns functions identical to those of a telephone switchboard to one of the telecommunications stations, an operation identical to that of a private radio network is obtained. virtual.

According to one embodiment, the management means include means for authorizing access to predetermined functionalities, from information which is stored in the server and which is associated with the addresses of the stations. Specific levels of network access are thus created within the network. Thus, for example, at least one of the stations can have extended functionalities and constitute a telephone switchboard, said switchboard forming part of the means for managing the links.

In order to increase the security of the network and prevent its access to unauthorized third parties, the server may include means of identifying the bearer of each station in the restricted network.

According to a particular embodiment, the server center is provided with means for interfacing the network with other telecommunications networks. It is thus possible to send and receive calls from other networks, for example via a set having functionalities identical or similar to those of the switchboard.

According to yet another advantageous embodiment, the server comprises means for decoding position information of the stations in order to manage the links between the stations according to their location. In this case, for example, when one of the stations has the functionalities of a telecommunications switchboard and when this station is used to manage the allocation of vehicles of a fleet, this positioning information can be used to proceed to management of vehicle allocation.

According to yet another embodiment, the network comprises encryption means for the transfer of data in a secure manner.

The network may be a mobile network or a wired network with permanent connection or a mixed network having fixed or wired accesses, and accesses of the mobile type.

According to the invention, there is also proposed a method for placing telecommunications stations in communication via a telecommunications network as defined above, comprising the steps of:

- putting the stations in communication with the server center;

- checking the address of each telecommunication station so as to verify that the station belongs to all the stations authorized to be put into communication via the restricted network; and

- Establishment of a link between said stations under the control of the management means and according to functionalities specific to each station.

Advantageously, there is provided a step of identifying the bearer of each station, subsequent to the step of placing the stations in communication with the server center.

Other objects, characteristics and advantages of the invention will become apparent on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

- Figure 1 schematically illustrates a first embodiment of a telecommunications network, mobile type, according to the invention,

- Figures 2a to 2d illustrate a first mode of operation of the telecommunications network of Figure 1;

FIGS. 3a to 3d illustrate the operation of the network of FIG. 1 during an attempt to put an unconnected subscriber into communication;

FIGS. 4a to 4f illustrate the operation of the network during the establishment of a general call intended to be broadcast to all the stations of the restricted network;

- Figures 5a to 5e illustrate the operation of a network according to the invention, in conference mode; and

- Figures 6a to 6c illustrate the operation of the network during the establishment of a call from outside the restricted network;

- Figures 7a to 7c illustrate the operation of the network during the establishment of a call to a station outside the restricted network; and

- Figures 8a to 8c illustrate the operation of the network during a secure transfer of data.

FIG. 1 shows the general structure of a telecommunications network in accordance with the invention, designated by the general reference numeral 10.

In the exemplary embodiment shown, the invention applies to a telecommunications network of the mobile type, such as a network using a GPRS (“General Packet Radio Service”) data transmission service or a network. using a universal telecommunications system with mobiles or UMTS (“Universal Mobile Telecommunication System”). It will nevertheless be noted that the invention also applies to fixed telecommunications networks, such as networks using digital subscriber lines with asymmetric flow or ADSL (“Asymmetry Digital Subscriber Line”), ie. that is to say, in general, networks which can establish a permanent connection with a server.

In the exemplary embodiment illustrated in FIG. 1, which uses a telecommunications network of the mobile type, this network comprises a set of cells, such as C1, C2. As can be seen in this figure, each cell C1, C2 is linked to a base station BST (“Base Transceiver Station”) which has an antenna making it possible to enter into communication with mobiles of the cell, by radio waves. Each cell is provided with a number of BST base stations determined in particular as a function of the traffic density.

Each base station is connected to a base station controller BSC (“Base Station Controller”) which manages the radio resources of the base stations which depend on it.

MSC (Mobile Service Switching Center) communication centers ensure the interconnection of the base stations with each other, as well as the interconnection of the mobile network with other telecommunications networks, such as the network. PSTN switched telephone.

It will be noted that the network 10 is constituted by a network of the permanent connection type, that is to say a network in which, as soon as each of the mobile stations is put into service, and as long as this station is located in a geographical area covered by a base station, a connection is established with the base station.

Moreover, as can be seen in FIG. 1, the network 10 is provided with a server center 12 intended to create, within the network 10, a restricted and confidential network accessible only to a certain number of predetermined mobile stations.

To this end, the server center 12 incorporates, stored in memory, a list of addresses corresponding to the mobile stations authorized to belong to this restricted network, as well as software means for managing the link between these stations of the restricted network.

It comprises means of authentication / identification of the carriers of the mobile stations so as to verify that the carriers of the stations are each authorized to access this restricted telecommunications network.

In addition, the server center 12 incorporates, in memory, for each station, a list of functions to which the station is authorized to access. Thus, and as will be described in detail below, the management means authorize the establishment of communications with the group of stations of the restricted network according to the functionalities available to each station.

By way of example, each station can have one or more of the following functionalities:

- general call: this functionality consists of offering one of the members of the restricted network the possibility of calling all of the other members and of receiving answers from them. The member at the origin of this general call can allow or withdraw the possibility for each member to hear the answers of the other members and to communicate with them.

- voice mail: this feature allows voice messages to be transcribed into written messages if the user so wishes or if the terminal does not have a listening system. This functionality also allows the translation of written messages into voice messages at the user's request or if the terminal does not have a screen. This functionality can be activated by the user or triggered by the detection of the type of terminal by the server 12.

- call of a sub-group of users: this functionality allows members of a sub-group of users to communicate with each other, in conference mode. This functionality can be launched after a preliminary registration phase for all the members of the sub-group, each member can activate this functionality. At the end of this preliminary phase, the server 12 sends a warning signal to each member connected to the server. After acknowledging this signal, each user is in a conference with the others. This conference can be vocal or take the form of written exchanges. In this case, when the members of the subgroup are equipped with different terminals which can operate in voice mode or in read / write mode, a written / voice translation system is provided to establish a mixed dialogue between the terminals.

- secure data exchange: this feature allows data to be exchanged between group members or between group members and the server according to security levels suited to current use (payment by electronic means, medical record, etc. ..).

- incoming call from outside: members of the restricted network have the possibility of receiving calls from a public network outside the restricted network. An incoming call is then received via one or more members having a switchboard operator function. These incoming communications are thus filtered before their transfer to the stations of the restricted network.

- outgoing call to the outside: the members of the restricted network can also call a subscriber of an outside public network through one or more switchboard members.

Thus, as can be seen, in order to be able to provide such functionality, in addition to the functionality information which is associated with each mobile station address, the server includes, stored in memory, information relating to the nature of each telecommunications station in the network. restricted. This information can either be automatically detected by the server, or stored in memory in the server when the restricted network is created.

In order to allow easy assignment of these functions, the stations are classified into groups of stations, each group of stations having a predetermined restricted network access level.

A basic level is thus distinguished, specifically intended for telephone terminals operating essentially in voice mode, a switchboard operator level, as well as a supervision level.

At the basic level, basic functionalities such as general call, voicemail, subgroup call, incoming call from outside and outgoing call to the public network are associated. The attendant level offers the functions of the basic level and an additional function for supervising the state of the terminals, namely free, busy, etc. If necessary, an additional functionality according to which the sets of the attendant level have the position members' geographic location, is offered if the terminals have a location function or if the network is capable of providing this information. In addition, the operator level telephones have the classic functionality of a switchboard, as well as the functionality of interfacing with other networks. Finally, the supervision level offers the functionalities of the basic level and additional functions of management of the profile of each member of the restricted network and of traffic management.

When developing the restricted network, the telecommunications operator providing this service records the contact details, such as Internet addresses, telephone numbers, etc., of each member. He communicates to each member a username and a password.

Furthermore, the list of mobile stations authorized to form part of the restricted network thus produced is stored in memory in the server 12 in the form of a list of identifiers each corresponding to a mobile station of the restricted network. Each identifier is associated, as indicated above, with a list of information necessary for the operation of the restricted network, such as identifiers, functionalities, the type of corresponding set, etc.

We will now describe various operating modes of the network which has just been described.

Referring firstly to Figures 2a to 2d, we will first describe a first mode of operation of the network according to which a subscriber A requests the establishment of a communication with a subscriber B. To do this, the subscriber A transmits to the server 12 a request tending to establish a communication with the subscriber B, this request containing the address of this recipient subscriber (FIG. 2a). The server 12 then transmits to the subscriber B a specific signal intended to indicate to the latter that a communication request has been formulated, this signal preferably containing information allowing the subscriber B to know the origin of the call. (figure 2b). After acceptance of this communication request (FIG. 2c), a communication is then established by the server 12 (FIG. 2d).

Referring now to Figures 3a to 3d, in the case where the subscriber B is unavailable, after establishment of the request by the subscriber A (Figure 3a), the server 12 transmits to the latter a message offering him access. to a messaging system (figure 3b). If this proposal is accepted, subscriber A proceeds to deposit a message in subscriber B's voice mailbox (FIG. 3c). As soon as subscriber B is available, the server 12 transmits to the latter a signal intended to indicate to him that a message has been left in his voice mailbox (FIG. 3d).

Referring now to Figures 4a to 4g, the restricted network can also be used to generate a general call to all the mobile stations A, B, C, ..., X connected to the server 12. To do this, l One of the subscribers, for example the subscriber carrying the mobile station A transmits to the server 12 a general call request, in the form of a specific signal. In response, the server 12 transmits to it an acceptance signal and transmits to the subscriber A sender of the general call the list of connected members available to receive the message (FIG. 4b). During the next step, subscriber A records the message to be broadcast (FIG. 4c). During the next step, shown in FIG. 4d, the server 12 proceeds to broadcast the message to all the mobile stations. Subsequently, some of the subscribers can respond to this message (FIG. 4e), these responses then being sequentially broadcast to station A (step 4f).

Referring to Figures 5a to 5e, for the establishment of a conference between several stations of the restricted network, it is appropriate to transmit to the server 12 a request for the establishment of such a conference (Figure 5a). With this request, the subscriber A sender of this request defines a subgroup of subscribers with whom he wishes to enter into a conference, by providing the server 12 with the list of stations B, ..., X of these subscribers. During the next step, shown in FIG. 5b, the members of the sub-group thus formed receive a warning message. When one of the subscribers, such as subscriber B transmits to the server 12 an acceptance message, by which he agrees to enter into a conference with subscriber A, the communication is established and the latter is informed of the arrival of subscriber B in conference (FIG. 5c).

Likewise, as can be seen in FIG. 5d, when another subscriber X accepts to enter a conference, subscribers A and B are then notified of his arrival in conference. At the end of the conference, the subscriber A transmits to the server 12 a signal intended to cause the termination of the conference. Subscribers B and X are then notified of the end of the conference and the conference ends.

Referring now to Figures 6a to 6c, a subscriber Y to a public network outside the restricted network can call one of the members of the restricted network to establish a telephone communication with the latter.

To do this, the external subscriber Y calls the switchboard of the restricted network (FIG. 6a), which checks the state of the set of called subscriber A and the call so as to indicate the arrival of the call in from external station Y (figure 6b). If subscriber A is available and accepts this communication, the switchboard causes the transfer of the communication to subscriber A (FIG. 6c).

To call an external station Y, subscriber A calls the switchboard and sends it a request to establish a communication with an external station (FIG. 7a). In response, the switchboard establishes a communication with the external subscriber Y, by calling the latter. As soon as he obtains this communication, he calls A and transmits the communication to him (FIG. 7c).

Finally, with reference to FIGS. 8a to 8c, the telecommunications network according to the invention can be used to transfer data to a recipient in a secure manner. To do this, the subscriber A transmits to the server 12 a request for the execution of a secure transfer of data (FIG. 8a). The server 12 then implements a security module capable of encrypting the data to be transferred, calls the recipient Y of the data and then causes the secure transfer of the data to the latter (FIG. 8b). At the end of the transfer, the subscriber A transmits to the server 12 a command to stop the secure transfer (FIG. 8c).