LT4603B - Equipment for switching between diferent telephone network terminals - Google Patents

Abstract

The equipment for switching between a first radio terminal (4) and a second terminal (3) of two telephone networks differently associated (2, 5), respectively, comprises: linking means (11, 12, 121, 122) for connecting the two terminals (3, 4); and means for controlling (20) the linking means (11, 12) controlled by one of the two terminals (3, 4) and means for switching off (11) the connection between one of the terminals (3) and its associated network (2) are provided.

Description

Exterior views of telephone networks operating over radio channels, such as the GSM network, provide users with high connectivity flexibility. However, each of these networks has only a limited geographical coverage. In addition, these networks, be they radio or public switched telephone networks (PSTNs), are all so different that their respective terminals are not interchangeable.

A wired interface is known in the art which allows a cellular transmitter-receiver to make and receive calls using both cellular and wired services (WO 94/17639).

The issue raised by the applicant may be considered when the user is using a GSM mobile telephone terminal at home and when the telephone terminal is connected to a PSTN. When the user is at home and his GSM mobile terminal is bypassed for convenience, the user may be at some distance from it and, at the same time, may be close to another terminal he is not calling.

In short, the applicant is considering the problem of interchangeability of terminals, at least from a functional point of view.

That's it! The present invention provides a device for connecting at least a first radio terminal 20 to a second terminal from two different respective connected telephone networks, comprising:

- connecting means for connecting the two terminals together;

- and control means for controlling said connection means controlled by at least one of two terminals.

In this way, the call can be diverted from one terminal to another.

The network that offers the most enticing technical characteristics or rates can also be selected for the outgoing call.

The invention will be more readily understood by reference to the description of the preferred embodiments of the connection device according to the present invention, given by way of example with reference to the accompanying drawings, in which:

- FIG. 1 is a very schematic representation of the connection function of the coupling device 5,

- FIG. 2 is a view of the device shown in FIG. 1, block diagram.

The switching device, denoted by 1, is shown connected to a public switched telephone network (PSTN) telephone line 2, to a telephone terminal 3 for connection to a PSTN and to a telephone handset 4 capable of connecting to a GSM radiotelephone network 5.

The connection device 1 allows separate connection of the terminal 3 with either the PSTN 2 or the telephone handset 4 with the GSM network 5 as shown in FIG. 1 and as will be explained below. In the figure, the two links indicated by arrows represent the Device 1 switching commands from Terminal 3 and Terminal 4, respectively.

As shown in Figs. 2, the device 1, defined by a dotted line, has a directional selection or switching system formed by two identical relays 11, 12, the main function of which is illustrated in FIG. 1. For clarity of the diagram, terminals 3 and 4 are shown disconnected from Device 1.

Although only one directional relay is shown in Figs. 1, but here is an opportunity for the Call Voltage Adjustment overhead, which requires additional contacts. They may belong to the same relay or another relay of the same type. The latter option has been chosen in order to distinguish more clearly between the various directional selection functions. As a result, the Direction Selection function of Figure 1 is shown in Figure 2 through relay contact levers 11, 12 which are left to right, as will be explained below.

Relay 11 has two contact levers, each with two contact positions: initial and active (2RA). The two pivotable ends of the movable levers are respectively connected (at positions 221, 222) to a switch 22 forming a connection with the two wires of line 2. Two corresponding initial contacts are connected (at positions 231, 232) to a switch 23 forming a connection to terminal 3, while the two active contacts activate (at positions 111, 112) the call voltage setting circuit 13.

Relay 12 has pivotable ends of two contact levers connected by wired links 121,122 to two / four-way exchange circuit 14. Two active contacts are respectively connected to connections 231,232 leading to terminal 3.

Circuit 14 is coupled to a switch 24 connecting GSM telephone handset 4 with two pairs of wires for transmission and reception, respectively.

The microprocessor 20 coupled to the switch 24 controls the relays 11, 12 via the interface circuit 16 and coupled to the output of the detector circuit 13. Microprocessor 20 is also connected in both directions to a switch 23 for V24 data lines and a separate circuit 15. The latter isolates the voltage between PSTN line 2, microprocessor 20 and group of switches 24, together with relays.

11, 12, detector 13 and double / quadruple exchange circuit 14. In this way, the GSM terminal 4 is electrically isolated from the PSTN line 2.

A charging element 17, powered from an AC source, coupled to a switch 24 for recharging the elements of a telephone handset 4. It is also coupled to the microprocessor 20 such that the latter can control the loading member 17 to provide an optimal loading frequency over time.

The contact of the switch 24 coupled to the microprocessor 20 transmits the presence signal of the telephone 4 to the microprocessor. The connection of this contact to the microprocessor 20 is shifted through the load resistor to the supply voltage of the microprocessor 20. The GSM telephone handset 4 is provided with a corresponding switch having a grounding lever such that said grounding operates when the handset is turned on.

There is a manual control switch 18 that controls the microprocessor 20 to control the switch group 11,12.

In the example, the terminal 3 is essentially comprised of a cordless telephone and a base station having a unit 1 and a support or socket (24) for a GSM telephone handset 4. Thus, the latter is powered from this base station via a charging element 17. In other examples The switches 22, 23, 24 may be remotely connected to the stationary device 1 by wire, optical (e.g., infrared) or radio communication.

Terminal 3 also has a local power supply similar to a charging cell 17, not necessarily battery connected to wires 121, 122, to move it toward terminal 3 DC power supply when the latter is isolated from the PSTN line 2 by an on / off relay 11, 12. , which switches terminal 3 to the aforementioned local power supply.

The operation of the connection device will now be explained.

In the first case, starting from the starting position, in the absence of a telephone call, the incoming call from the PSTN 2 goes through relay 11 and forces the terminal 3 to send the call signal and set up the telephone connection in the usual way. During this phase, the GSM telephone handset 4 may be disconnected from the switch 24, if necessary, to establish a sending or receiving GSM call. In this way, terminals 3 and 4 are independent of each other.

In the second case, still starting from the initial position, the incoming call from the GSM network 5 passes through the GSM handset 4, arriving as before to the terminal 3. Thus, the GSM telephone handset 4 audio connection circuits (connected to the microphone and speaker). are output to a two-wire / four-wire audio signal tuning circuit 14 via a switch 24. The dual wire reaches terminal 3 via a relay 12 which is switched to a working position by microprocessor 20. The cut-off relay 11 is similarly turned on to its working position by isolating the PSTN line 2 from the terminal 3 now occupied and connecting this line to the call voltage detector 13 to alert a possible second incoming call currently leaving the PSTN 2. In this case, the microprocessor 20 sends V24 signals alerting the presence of a call to the PSTN to terminal 3, which issues an audible signal to the user. The user of the terminal 3 can then receive the call by activating a switch 18 which controls the relays 11, 12. The user can terminate this connection via PSTN 2 and then switch direction selection elements 1.1, 12 to generalize the connection on the GSM network.

5.

The microprocessor 20 is itself controlled from at least one of the terminals 3 and 4. In the example, the terminal 3 essentially stores all connection status information (about PSTN or GSM calls received and received) to regulate the microprocessor 20 itself and has the appropriate software. Therefore, the GSM handset 4 transmits to the terminal 3 all information related to GSM transmissions.

This information is transmitted through a microprocessor 20 which couples the switches 23 and 24 together with the circuit 15.

During this phase, the microprocessor 20 is open, i. he usually transmits this information without interpreting it.

The third case involves outgoing calls, Terminal 3 connects to

PSTN 2 in the classic way. The switch 18 allows control of the directional selection elements 11,12 for the outgoing call to the GSM network 5.

It is to be understood that the switch 18 is provided herein, inter alia, for heuristic reasons and that the control of the directional selection elements 11,12 could go either from one terminal 3 to another terminal 4 by activating a button on the latter.

The device according to the invention can be adapted to accommodate different types of telephone terminals, whether analogue or digital, with a suitable analogue-to-digital converter, if necessary. At the user's choice, forwarding of incoming calls to one or another terminal may be used by modifying directional selection elements known to those skilled in the art.

Definition of the Invention

Claims (10)

Definition of the Invention A device for connecting at least a first radio communication terminal (4) and a second terminal 5 (3) to two different, respectively connected telephone networks (2, 5), characterized in that it has: - connecting means (11, 12, 121, 122) for connecting the two terminals (3, 4) together; and control means for controlling said coupling means (11, 12) adjustable by at least one of two terminals (3, 4). Device according to Claim 1, characterized in that the tripping means (11) are arranged between one of the terminals (11). 3) and its associated network (2). 3. Device according to claim 2, characterized in that the trip means (11) are connected to switch said terminal (3) to a local power supply. Device according to one of Claims 2 and 3, characterized in that the switching means comprise a switching relay (11) connected to the telephone to be connected. 20 network line (2). 5. Apparatus according to claim 4, characterized in that the switching means are arranged for connecting the line (2) to the call detector (13). 25th Device according to one of Claims 1 to 5, characterized in that the coupling means (121, 122) are wires. 7. A device according to claim 6, further comprising a power supply (17) for the radio terminal (4) and comprising a support for the terminal (4). 8. Device according to one of claims 1 to 7, characterized in that the control means comprise a microprocessor (20) connected to two switches (23, 24) for connection to the terminals (3, 4). 5 Device according to claim 8, characterized in that one of the switches (24) has a contact for detecting the presence of the first terminal (4). Device according to one of Claims 1 to 9, characterized in that the first terminal (4) is of the GSM type and the second terminal (3) is of the wired type and the tuning means (14) are connected to harmonize the audio signals between the two terminals (3). 4). 1/2