GB2283881A

GB2283881A - Telephone communications assembly

Info

Publication number: GB2283881A
Application number: GB9422816A
Authority: GB
Inventors: Michael Bryan Davison
Original assignee: SDX Business Systems PLC
Current assignee: Avaya ECS Ltd
Priority date: 1993-11-12
Filing date: 1994-11-11
Publication date: 1995-05-17
Also published as: GB9422816D0; GB9323357D0

Abstract

A telephone communications assembly comprises a switch (5) having at least two extension ports (2, 4) and at least one trunk line port (6, 7) connectable to the extension ports. A telephone transmitting and receiving device (9) is connected to one of the truck line ports (6), the device being adapted for use directly in a public, non-wired communication network. <IMAGE>

Description

TELEPHONE COMMUNICATIONS ASSEMBLY The invention relates to a telephone communications assembly comprising a switch having at least two extension ports and at least one trunk line port connectable to the extension ports.

Assemblies incorporating such switches are known in the form of private branch exchange equipment (PBX) and the like and conventionally such equipment is connected via the or each trunk line port to a public switched telephone network (PSTN).

One problem which arises with conventional private branch exchange equipment is linking that equipment to a PSTN when the equipment is inaccessible by cable or where a microwave link is not cost-effective. In such situations, the use of a PBX is not possible.

One approach to solving this problem is described in US-A-4890315. This describes the connection of a switch to a radio telephone which communicates with a remote base station which in turn is connected to a land line telephone system. The drawback of this approach is that a specialised radio communication link must be set up between the remote units and effectively this constitutes a radio communication tied line. Communication bandwith is limited.

In accordance with the present invention, a telephone communications assembly comprises a switch having at least two extension ports and at least one trunk line port connectable to the extension ports; and a telephone transmitting and receiving device connected to the or one of the trunk line port(s), the device being adapted for use directly in a public, non-wired communication network.

We have realised that it is possible to connect a private branch exchange switch directly to a telephone device, such as a mobile or cellular telephone device, using an existing approved trunk line interface and hence enable land line based extensions to use the public, non wired network directly. This enables the problems outlined above to be overcome and also avoids the need to use an intermediate PSTN with the result that the cost of accessing someone having a mobile telephone, for example, is reduced. A further advantage is that the assembly is substantially self-contained and can be moved from building to building without the need for physical connections to an outside carrier.

This is particularly useful in the case of building sites, for example. Typically, a portable office is taken to a building site. The office will include a PBX and a number of extensions and conventionally has be to connected to a specially provided, land line based trunk. The invention avoids this altogether by linking the PBX into a mobile telephone device which are carried together in the portable office.

Another important application is in building security where conventionally an alarm is connected to the switch so as to call a remote telephone when activated. This has the drawback that the land line telephone can be cut thus preventing the remote alarm call. With the invention this problem is overcome by avoiding use of the land line.

In some cases, the assembly may further comprise a second trunk line port connected to another telephone communications network. This might be, for example, a hard wired connection of a conventional type. In that case, preferably, the switch further includes a detector for detecting the destination of a call from an extension port and causing the switch to route the call to one or other of the trunk line ports as appropriate. Thus, if the destination is a telephone within the mobile telephone network then the switch will route the call via the first trunk line port but otherwise via the second trunk line port.

An example of a telephone communications assembly according to the invention will now be described with reference to the accompanying drawing which is a schematic, block diagram.

The drawing illustrates a private branch exchange switch 1 connected to a number of extensions, of which three are shown 2-4. These can be any form of telephone communication device and are shown in this example as telephone handsets 2,3 and a fax machine 4. The switch 1 includes a switch unit 5 connected to a pair of trunk line ports 6,7 and to the extensions 2-4 via a switch controller 8. The switch unit 5 is able to route calls between any of the extensions 2-4 and either of the trunk line ports 6,7 and in either direction.

The trunk line port 6 is connected directly to a mobile telephone 9 forming part of a cellular PSTN 10. The mobile telephone 8 is shown in the drawing as being a separate unit from the switch 1 although in practice it may be embodied within the switch assembly and not be separately movable. The trunk line port 7 is connected via a hard wired connection or radio link to a conventional PSTN network 11.

In operation, a user dials a desired number on one of the extension devices, for example the device 2. The dialled telephone number is sensed by the controller 8 within the switch 1 and the controller determines in a conventional manner, from the first few digits, whether the called telephone is within the mobile telephone network 10 or not. If it is within the mobile telephone network, then the controller 8 actuates the switch unit 5 to route the call to the trunk line port 6 and hence to the mobile telephone unit 9. The unit 9 then dials the appropriate number as supplied from the extension 2 and switch unit 5 so that the call is initiated directly in the mobile telephone network. If the called telephone is not within the mobile telephone network then the controller 8 causes the switch unit 5 to route the call via the trunk line port 7 to the conventional PSTN 11.

In other applications, only the port 6 is provided so that all calls are routed via the mobile telephone 9.

Claims

1. A telephone communications assembly, the assembly comprising a switch having at least two extension ports and at least one trunk line port connectable to the extension ports; and a telephone transmitting and receiving device connected to the or one of the trunk line port(s), the .

device being adapted for use directly in a public, nonwired communication network.

2. An assembly according to claim 1, wherein the public, non-wired communication network is a radio communications network.

3. An assembly according to claim 2, wherein the radio communications network is a cellular network.

4. An assembly according to claim 3, wherein the cellular network is a mobile telephone communication network.

5. An assembly according to any of the preceding claims, wherein the switch includes a second trunk line port connected to another telephone communications network.

6. An assembly according to claim 5, wherein the switch further comprises a detector for detecting the destination of a call from an extension port and causing the switch to route the call to one or other of the trunk line ports as appropriate.

7. A telephone communications assembly substantially as hereinbefore described with reference to the accompanying drawing.