GB2356773A

GB2356773A - A radio interface unit controlled by a standard telephone

Info

Publication number: GB2356773A
Application number: GB9928137A
Authority: GB
Inventors: Robert Wisniewski; Edward P Morton
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 1999-11-26
Filing date: 1999-11-26
Publication date: 2001-05-30
Also published as: GB9928137D0

Description

2356773 TELEPHONE APPARATUS

TECHNICAL FIELD OF THE INVENTION

This invention relates to an interface unit, which allows a user to gain access to a radiocommunication network, by connecting a standard telephone thereto.

In particular, the invention relates to an interface unit which can be reset from the standard telephone.

BACKGROUND OF THE INVENTION

W099/13659 describes an interface unit, which allows a fixed subscriber, using a standard telephone, to gain access to a satellite or cellular radio telephone system. The advantage of such an interface is that it allows the provision of a telephone service to the subscriber, without the need to establish a fixed link. For subscribers in remote areas, therefore, it can be economically advantageous to provide.the telephone service by means of an interface unit of this type.

In use of the interf ace unit, it may be advantageous to position it in a relatively inaccessible location, for example to avoid tampering, or to minimise visual disturbance.

However, it is necessary to provide a method of resetting the unit, that is, returning the unit to an initialization condition.

Because the unit may be relatively inaccessible, it is therefore preferable that the unit should be able to be reset from the standard telephone.

SUMMARY OF THE INVENTION

This invention relates to an interface unit, which allows a standard telephone set to be connected to a radio telephone transceiver, and which is reset when it detects that a hookswitch of the telephone set has been operated in accordance with a predetermined criterion.

For example, the predetermined criterion may be that the hookswitch has been released a specified number of times without any call having been made. As another example, the predetermined criterion may be that the hookswitch has been released a specified number of times within a particular time period.

These criteria may be combined.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a block schematic diagram of an interface unit in accordance with the invention.

Figure 2 is a flowchart showing a mode of operation of a unit in accordance with the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows a telephone system including an interface unit 2 in accordance with the invention. The is unit 2 includes a radio transceiver 4 which communicates with a network, such as a cellular or satellite radio telephone network, via an appropriate antenna 6. The transceiver is under the control of a micro controller and associated memory 8. The unit 2 further includes a subscriber line interface circuit (SLIC) 10, which is also under the control of the micro controller 8, and to which a standard DTMF phone 12, or other DTMF generator, may be connected. A DTMF detector 14 monitors signals output from the SLIC 10 in response to dialled tones and other signals received thereby, and is connected to the micro controller 8. A tone generator 16, acting under the control of the micro controller 8, generates ringing and other tones for supply to the SLIC 10, for transmission to a user.

The SLIC 10 is also connected to the radio transceiver 4 for audio communication.

Figure 2 is a flow chart showing an algorithm used by the interface unit of the present invention. The algorithm is embodied in the operating software of the micro controller 8, which interprets and acts upon signals received from the SLIC 10, which in turn detects DTMF tones and other signals received from the telephone set, representing specific operations carried out at the telephone set.

In particular, the SLIC is able to detect whether the telephone set is on hook or off hook, and sends a corresponding signal to the micro controller 8. The invention, in this embodiment, lies in the way in which the micro controller 8 interprets and acts upon, such signals.

The method starts at step 22 and, at step 24, it is detected that the telephone has been taken off the hook, that is, that the hookswitch has been released.

In response to this, at step 26, a count value OFF-HOOK-DETECT is increased by one. Further, if the count value reaches the value 1, an off hook reset control timer is started.

Incidentally, if, at any stage, the off hook reset control timer expires, that is, the counted time reaches a specified value, then the method passes to step 28, and then to step 30, in which the off hook reset control timer is stopped and reset, and the count value OFF-HOOK-DETECT is reset to zero. In a preferred embodiment, the specified value is configurable by an operator, but it may typically be set to 15 minutes, for example.

Following the increase in the count value OFF-HOOK-DETECT at step 26, the method passes to step 32, in which it is determined whether the count value OFF-HOOK-DETECT has reached a threshold value X. In a preferred embodiment, the threshold value X is configurable by an operator, but it may typically be set to 6, for example.

If the count value OFF HOOK DETECT has reached the threshold value X, then the method passes to step 34, and the interface unit is reset. In other words, the operating software is forced to jump to the location at which it would restart if the power to the unit were switched off and then on again. The unit is thus set to an initialization condition.

The unit can theref ore be reset by a user, by means of the standard telephone set, without directly accessing the interface unit, by taking the standard telephone set off hook and on hook repeatedly within a specified time period.

If the unit is not reset, because step 32 determines that the threshold has not been reached, the method proceeds to step 36. In step 36, normal call set-up procedures are begun, although they are of course terminated if the telephone set is put back on hook.

In. step 38, it is determined whether a call has been connected. A determination is made that a call has been connected if the user makes a connection to a called party or if the user obtains an engaged tone, for example. If it is determined that no call has been connected, the method proceeds to step 40, and continues, for example, to detect future occasions when the telephone goes off hook.

However, if it is determined in step 38 that a call has been connected, that is, that the user has made a connection to a called party or has obtained an engaged tone, for example, then the method passes to step 42. In step 42, the of f hook reset control timer is stopped and reset, and the count value OFF-HOOK-DETECT is reset to zero. Thus, once the timer and count values have been reset in step 42, the process of counting the number of times that the telephone is taken off hook is restarted.

There is therefore disclosed an interface unit, and a control method thereof, which allow a remote user, connected to the unit by means of a standard telephone, to reset the unit.

It will be appreciated that the interface unit may be controlled on the basis of any specified sequence of operation of the hook switch of the remote telephone, either in combination with or separately from operation of other keys of the remote telephone. Moreover, although the invention has been described with reference to resetting the interface unit, any other feature of the interface unit may be controlled in a similar way. For example, as a test of a telephone set, the interface unit may operate in response to a particular sequence of hook switch operations and other key presses to cause the telephone set to ring.

Claims

1. An interface unit, having means for connecting a standard telephone set thereto, and having a radio transceiver, and further having means for detecting operation of a hookswitch on a standard telephone set connected thereto, wherein the unit is reset when it detects receipt of signals representing operation of a hookswitch on the telephone set, meeting a predetermined criterion.

2. An interface unit as claimed in claim 1, wherein the predetermined criterion relates to receipt of a specified number of signals each representing one release of a hookswitch within a specified time period.

3. An interface unit as claimed in claim 1, wherein the predetermined criterion relates to receipt of a specified number of signals each representing one release of a hookswitch within a specified time period, without an intervening successful call connection.

4. An interface unit as claimed in claim 1, wherein the predetermined criterion relates to receipt of a specified number of signals each representing release of a hookswitch without a specified alternative DTMF tone intervening.

5. An interface unit, having means for connecting a standard telephone set thereto, and having a radio transceiver, and further having means for detecting signals received from a standard telephone set connected thereto, wherein the unit is controlled on the basis of signals representing operation of a hookswitch on the telephone set.