WO1992003003A1

WO1992003003A1 - Electrical apparatus for simulating functions of a complex switching device

Info

Publication number: WO1992003003A1
Application number: PCT/GB1991/001336
Authority: WO
Inventors: David Watkins
Original assignee: Good Thinking Limited
Priority date: 1990-08-09
Filing date: 1991-08-05
Publication date: 1992-02-20
Also published as: AU8298391A; GB9017535D0

Abstract

Portable electrical apparatus for simulating functions of a complex signal switching device, such as a telephone exchange, comprising electrical circuitry and at least two connectors (2, 3) for connecting communications apparatus (4, 5), e.g. telephones or modems, to the circuitry, the circuitry including simulation means (8, 11) for generating predetermined simulated signals, such as a dial tone signal, a ring tone signal etc., and control means for controlling the supply of the simulated signals to the connectors (2, 3), whereby the communications apparatus (4, 5) can be tested or demonstrated without needing to use a conventional telephone line.

Description

ELECTRICAL APPARATUS FOR SIMULATING FUNCTIONS OF

A COMPLEX SWITCHING DEVICE

TECHNICAL FIELD

The present invention relates to electrical apparatus for simulating functions of a complex switching device such as a conventional telephone exchange.

BACKGROUND ART

It is now very common-place for signals from various communications sources to be sent, via a telephone or similar link, to other apparatus adapted to receive such signals. An example is a computer associated with a modem which sends signals, through a telephone link to another modem connected to another computer. A further example is a facsimile machine which sends signals through a telephone line to another facsimile machine. Yet another example is a video conferencing terminal which sends signals through a high-speed data network to another video conferencing terminal.

When it is desired to test or demonstrate apparatus of this type, even if a sending apparatus and a receiving apparatus are present in the same building, it is necessary to utilise an appropriate signal exchange mechanism in order to ensure that the apparatus is operating in a satisfactory manner. This can clearly prove to be inconvenient if the sending and receiving apparatus cannot both be connected to the signal exchange mechanism (e.g. by means of normal telephone lines) at the same location. Even if two telephone lines are available, e.g. on an internal private automatic branch exchange (PABX) signal switching device, the telephone sockets for the sending and receiving apparatus are still usually physically far apart and it is necessary for the sending apparatus to provide routing information (e.g. the telephone number) for the relevant receiving apparatus. In addition, the two lines will be unavailable for making and receiving other calls whilst the apparatus is tested.

DISCLOSURE OF INVENTION

The present invention seeks to provide an electrical apparatus that can be used when testing or demonstrating apparatus that normally sends slgnals through a telephone or similar link.

According to a first aspect of the invention there is provided electrical apparatus for simulating functions of a complex signal switching device, the apparatus comprising electrical circuitry and at least two connector means for connecting communications apparatus to the circuitry, the circuitry including simulation means for generating predetermined simulated signals and control means for controlling the supply of the simulated signals to the connector means.

According to a second aspect of the invention there is provided a method of testing or demonstrating a communication device comprising the steps of: connecting the device to first connector means of electrical apparatus as described above, connecting another communications device to second connector means of the electrical apparatus and using the electrical apparatus to provide a connection between the two devices and thereby to test or demonstrate functions of at least one of the devices.

Preferred and optional features of the invention will be apparent from the following description and from subsidiary claims of the specification. BRIEF DESCRIPTION OP DRAWINGS

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, merely by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a block diagram of an embodiment of apparatus according with the present invention;

Figure 2 shows a more detailed block diagram of an alternative form of part of the apparatus shown in Figure 1: and

Figure 3 shows an overall block diagram of the arrangement shown in Figure 2. BEST MODE OF CARRYING OUT THE INVENTION

The apparatus described herein is contained within a housing 1 which is designed to be readily portable. The housing is provided with appropriate terminals or connectors 2, 3 to enable items such as modems 4, 5 to be connected to electrical circuitry within the housing 1. Of course, other devices which are normally utilised in conjunction with a telephone system may be connected to the described apparatus, such as two facsimile machines. The terminals or connectors 2, 3 may comprise conventional sockets adapted to receive conventional plugs as commonly provided on telephonic apparatus. It is to be understood that the housing may also be adapted to be connected to other devices used with other types of signal exchange equipment, such as video conferencing facilities etc.

Contained within the housing 1 is a power supply 6. The power supply 6 may be batteries, which may be adapted to be rechargeable, or may comprise a power supply adapted to receive mains electricity. Such a power supply would also incorporate a transformer.

The power supply 6 is connected to a control arrangement 7 which, in turn, is connected to simulation arrangements 8 to 11 which are respectively adapted to provide simulations of a dialling tone signal, a ringing tone signal, and an engaged tone signal and also to provide a simulated ring signal corresponding to the signals generated by a conventional telephone exchange. Details of such tones and signals are well known to the man skilled in the art, and can be found, for Instance, in British Standard BS 6305. Further arrangements may be provided to supply any other appropriate telephonic signals or tones. These tones may Include simulated line "noise", or simulated crossed lines. The control arrangement 7 may also be connected to a further terminal 12 to which a telephone hand-piece 13 or monitor may be connected, for example, by means of a jack plug or conventional socket, or the like.

The control arrangement 7 may comprise a plurality of manually operated switches adapted to provide the desired connections between the various items shown, and/or may comprise a micro-processor, which may be programmed to perform a similar function. Each of the simulation arrangements 8 to 11 for generating simulated tones or signals may comprise an appropriate oscillator and series of filters or may comprise a memory, in the form of a read only memory (ROM) for example, containing, in digital form, the appropriate tone or signal. In such a case, the control arrangement 7 includes a digital to analogue converter so that, when a particular tone or signal is required, the digital data in the ROM can be read and converted to provide the appropriate simulated tone or signal.

The control arrangement 7 may also be adapted to be operated to provide a poor or noisy connection between the terminals or connectors 2 and 3 to simulate a "bad line". Thus, the control arrangement 7 may include means for attenuating, amplifying and/or adding to the simulated signals. Also, signals from tone generators which generate noise or signals representing a crossed line may be mixed in, to provide a desired effect.

The apparatus may be utilised to test, for example, an arrangement incorporating two modems 4, 5. Each modem is connected to the appropriate connectors 2, 3 provided on the housing 1. The control arrangement 7 would then be operated so that initially a .simulated dialling tone signal is provided to the modem, e.g. modem 4, which is to initiate a call. In response to the. detection of an appropriate dialling signal from that modem by the control arrangement 7 (if in the form of a micro-processor or after an appropriate delay in the case of a control arrangement incorporating a plurality of switches), either the ringing tone simulator 9 or the engaged tone simulator 10 will be activated. If the engaged tone simulator 10 is activated, the simulated call should then be terminated by the calling modem 4. If the ringing tone simulator 9 is activated, then the ring signal generator 11 will supply a simulated ring signal to the connector 3 and hence to the other modem 5. After a predetermined period of time, a direct connection may be established between the modem 4 and the modem 5. Thus, the circuitry present within the housing 1 provides the connection between the connector 2 and the connector 3 with properties equivalent to the properties found on an ordinary telephone line. It is to be appreciated that if necessary voice connection can be established through the connector 12 using the hand-piece 13.

The control arrangement 7 may also be used to operate a visual display 14 to show the status of the apparatus. Means may also be provided to analyse and display details of tones received from devices attached to the connectors 2, 3.

It is to be appreciated that the apparatus as described may be adapted so that any one of the simulated tones may be made to present upon the connector 2 or on the connector 3. The control arrangement 7 may be adapted to detect dialling at one connector and to send a ringing slgnal through the other connector or vice versa. The apparatus may further be adapted to detect when a ringing signal has been answered and to establish connection between the two connectors 2 and 3 or may be adapted to establish connection between one of those connectors and the connector 12 and the associated hand-piece 13. The control arrangement 7 may also detect subsequent disconnection or termination of a connection and return to providing a simulated dialling tone.

The control arrangement is bi-directional so can supply appropriate signalε to sending and receiving devices irrespective of which connector they are connected to. The apparatus may simply be provided with two connectors for connecting to communication devices but other connectors may be provided if required.

In other words, the apparatus emulates the functions of a simple telephone exchange, although the apparatus is contained within an appropriate portable housing. Additional diagnostic ports may also be provided.

It is to be appreciated that for world-wide use it may be preferable to utilise ROM devices for simulating the various tones, and a programmable memory may be required to select the correct tones relevant to each particular country. Flgure 2 shows a box diagram illustrating an alternative form of the control and simulation arrangements. The arrangement shown in Figure 2 comprises a pulse generator 15, a monostable device 16, a dial tone oscillator 17, a mixer circuit 18, a delay circuit 19, a ring tone oscillator 20, a ringing oscillator 21, a transformer 22, a sensing circuit 23, a relay 24 and associated contacts 28, a receive socket 3, and a send socket 2.

The relay 24 controls the mode of operation of the arrangement, i.e. either data transmission mode or signalling mode. The mode is set by the status of the apparatus attached to the receive socket 3.

In the signalling mode, the relay contacts 28 are open (as shown) so that data communication between the send socket 2 and the receive socket 3 is broken, with the apparatus attached to the receive socket 3 and the apparatus attached to the send socket 2 both being in a passive state (e.g. both 'on hook' for two telephones). When the apparatus attached to the send socket 2 is activated (e.g. taken 'off hook' for a telephone), it activates the pulse generator 15, this causes the monostable device 16 to be activated and the delay circuit 19 is activated. The monostable device 16 activates the dial oscillator 17 which sends a simulated dialling tone to the apparatus attached to the send socket 2. If the pulse generator 15 continues to be activated, e.g. if a sequence of dialling pulses are received from the apparatus connected to the send socket 2, the monostable device 16 and delay circuit 19 are reinitialised until the activity ceases and the delay expires, whereupon the ring oscillators 20 and 21 send signals to the send socket 2 and the receive socket 3, respectively. The transmission of ringing signals terminates when the sensing circuitry 23 detects that the apparatus attached to the receive socket 3 has responded to the ringing signals (e.g. the receiver has been picked up in the case of a telephone). This activates the relay 24 and closes the contacts 28 and so establishes a direct connection between the send socket 2 and the receive socket 3. The apparatus is thus in the data mode in which relay contacts 28 are closed so that a free and unrestricted data communication is established between send socket 2 and the receive socket 3. When connection between the send and receive sockets 2, 3 is terminated (e.g. by both the sending and receiving device 'hanging up'), the sensing circuit 23 activates the relay 24 so as to open the relay contacts 28 once again.

A simple arrangement of a pulse generator 15, monostable device 16 and delay circuit 19 thus simulates the operation of a complex switching mechanism.

The ring ascillators 20 and 21 may be similar to each other and arranged to send the same frequency signal or combination of frequencies with the same relative amplitudes both as a ringing signal to the receiving device and as a ring-back signal to the sending device. Indeed, the same oscillator may be used to provide both the ringing signal and the ring-back signal.

The simulation arrangements used in either of the embodiments may be similar to the devices whose operation they are designed to simulate and may employ the same technology as used in a conventional switchboard or telephone exchange to generate the required signals and tones.

Figure 3 shows an overall box diagram of the arrangement shown in Figure 2, showing send and receive monitors 23, 24, 28 connected to send and receive sockets 2, 3, the control arrangement 15, 16, 19 and the simulation means 17, 18, 20, 21.

It will be appreciated from the description of the arrangements shown in Figures 1 to 3 that the apparatus functions automatically (or on operation of manual switches) to provide a connection between devices attached to the connectors 2 and 3 (if all the relevant conditions are met) but that routing information (e.g. dialling pulses representing the number 'dialled' by the sending device) is not required by the device. In fact, as described in relation to Figure 2, routing signals may simply be used to re-trigger the pulse generator 15 and hence the monostable device 16 and delay circuit 19. Thus, the control arrangement supplies a sequence of simulated signals to the sending device and then establishes a connection between the sending device and the receiving device. Unlike a conventional switchboard, it is the control arrangement 7 rather than the sending device which controls the supply, including the routing of signals to and between the connectors 2 and 3, the control being determined by the sensed status of the receiving device rather than by the sending device.

The apparatus described above can readily be provided in a small, portable housing, for instance no larger than 9 cm × 15 cm × 3 cm and weighing less than 400 g. It can therefore easily be carried in the hand and taken from location to location to test or demonstrate any form of communication device or other equipment which is normally connected by a public telephone line. It can be used at any location as it operates independently of the public telephone system. Existing telephone lines do not need to be occupied whilst the equipment is being tested or demonstrated and telephone charges for the use of such lines are not incurred. The apparatus may also be used in the development of a communications device and In training people to use such devices without incurring charges for using a conventional telephone line.

INDUSTRIAL APPLICABILITY

The apparatus described may be manufactured and used to test or demonstrate the function of communications equipment.

Claims

1) Electrical apparatus for simulating functions of a complex signal switching device, the apparatus comprising electrical circuitry and at least two connector means for connecting communications apparatus to the circuitry, the circuitry including simulation means for generating predetermined simulated signals and control means for controlling the supply of the simulated signals to the connector means.

2) Apparatus according to claim 1 wherein the simulation means are arranged to generate or emulate a dial tone signal, a ring tone signal and an engaged tone signal corresponding to the signals generated by a conventional telephone exchange.

3) Apparatus according to claim 1 or 2 wherein the simulation means are arranged to generate or emulate a ring signal corresponding to that generated by a conventional telephone exchange.

4) Apparatus as claimed in claim 2 and 3 wherein the same simulation means is arranged to generate the simulated ring tone signal and the simulated ring signal.

5) Apparatus according to any preceding claim wherein the simulation comprises means for attenuating, amplifying and/or adding to the signals supplied to the connector means for simulating a poor connection or other faults.

6) Apparatus according to any preceding claim wherein the simulation means comprises a read only memory (ROM) device containing digitally stored information and a digital to analogue converter is provided to generate the simulated signals therefrom.

7) Apparatus according to any preceding claim wherein the control means is arranged to supply a sequence of simulated signals to first connector means and then to establish a connection between the first connector means and second connector means, e.g. to simulate the operation of a conventional telephone exchange.

8) Apparatus as claimed in claim 7 wherein the control means comprises a pulse generator the output of which is connected to a monostable device and to a delay circuit the output of which are arranged to control operation of the simulation means.

9) Apparatus as claimed in claim 8 wherein the control means is arranged such that receipt of routing information from a sending device connected to one of the connection means re-triggers the pulse generator and hence the monostable device and delay circuit.

10) Apparatus as claimed in any preceding claim wherein the control means is arranged to control the supply of simulated signals to the connection means in dependence upon the sensed state of a receiving device connected to one of the connection means.

11) Apparatus according to any preceding claim wherein the control means is bi-directional and so can supply simulated signals appropriate for sending or receiving apparatus connected to any of the connection means.

12) Apparatus according to any preceding claim including connector means adapted to be connected to a hand-piece or the like for providing a voice connection to the apparatus.

13) Apparatus according to any preceding claim incorporating display means to display the status of the apparatus.

14) A method of testing or demonstrating a communications device comprising the steps of: connecting the device to first connector means of electrical apparatus as claimed In any preceding claim, connecting another communications device to second connector means of the electrical apparatus and using the electrical apparatus to provide a