CALL UNIT FOR USE IN AN EMERGENCY CALL SYSTEM

Abstract: A call unit for use in an emergency call system comprises speech receiving and transmitting means (11) capable of operating in a handsfree mode. A first non-volatile memory (10a) stores information determining the destination of an emergency call made from the unit. Such call is initiated by microprocessor operating means (9) operating in a normal mode in response to a control signal from a generator, for example a radio signal generator (6), located remote from the unit. This operation initiates dialling by an automatic dialler (8) to an emergency call destination, and on connection handsfree two-way speech communication is permitted. The unit includes switch means (16) having a first normal switching condition in which the microprocessor operates in the normal mode. The switch means (16) responds to an incoming call signal on the telephone line to adopt a second switching condition causing the microprocessor to operate in a receive mode. In this mode receipt of a control signal from the signal generator (6) causes the microprocessor to enable handsfree two-way speech communication between the call unit and the incoming caller without the user of the unit physically having to be present at the call unit itself.

Description: CALL UNIT FOR USE IN AN EMERGENCY CALL SYSTEM Technical Field This invention relates to a call unit for use in an emergency call system. Background Art Emergency call systems for elderly or infirm people are becoming widespread, both in sheltered housing schemes . and in ordinary residential locations. In large sheltered housing schemes emergency calls may be transmitted from equipment in a resident's dwelling to the office of a warden or guardian by way of a private intercommunication network. In some cases calls may be transmitted by way of the public telephone network to a remote monitoring or receiving station, usually staffed by personnel suitably trained and equipped to summon assistance for the calling resident. In a typical application to non-sheltered dwellings, i.e. application to an individual private home occupied by an elde.rly or infirm person, an emergency call unit would normally be connected directly to the subscriber telephone line serving the dwelling in question, and would incorporate an automatic dialling device actuated in response to an external stimulus to dial a call on the public telephone network. Following establishment of a connection with a remote receiving station, the unit would transmit data identifying the origin of the call to the staff of the receiving station, and in many cases also an indication of the manner in which the emergency call was initiated. In such an.application the initiation of the emergency call may be by specific manual actuation of a push-button or pull-cord alarm switch (which may be integrated with the unit or remote therefrom), by an environmental detection unit (for example a smoke detector), or by a device that responds to a prolonged period of inactivity in the dwelling where the call unit is located. Alternatively the call may be raised by a remote trigger device, for example a radio, infra-red or ultrasonic transmitter continuously worn or carried by the protected person or kept permanently in that person's vicinity. Such devices must of necessity be extremely simple, so that they may be operated by a person of possibly restricted mental capacity and limited dexterity.. For this reason, known remote alarm trigger devices generally feature a single large pushbutton as their only actuating means. Emergency call units of the type described may in some cases provide a speech facility, in addition to the data transmission facility, so enabling the staff at the receiving station to ascertain the nature of the emergency by dialogue with the caller. In such cases a loudspeaker and microphone are employed in the emergency call unit to provide a loudspeaking "handsfree" speech facility, with the speech direction under the control of the operator at the receiving station, thus eliminating the need for the ' protected person to perform any manual action such as pressing a switch or lifting a handset whilst making a call. Furthermoxe, control by the operator at the receiving station generally extends to clearing the call, thus ensuring that emergency calls cannot be accidentally disconnected by the caller. It will be understood from the foregoing that a unit of the type described is designed for the specific function of reporting an emergency situation, and thus cannot provide the communication facility available with an ordinary telephone, i.e. the facility of dialling a call to any selected destination. Conversely an ordinary telephone instrument cannot provide the facilities needed to provide the integrity of operation essential in an emergency call system, namely automatic dialling, transmission of data identifying the calling party, loudspeaking operation under control of the staff at the receiving station, and termination of calls by the receiving station staff only. Hence, in cases where the protected resident requires an ordinary telephone facility in addition to the emergency call facility, an ordinary telephone is often provided at the dwelling in question. Because of the high cost of provision of separate subscriber telephone lines for the emergency call unit and the ordinary telephone, it is conventional to connect both items of equipment to a common telephone line. A disadvantage of this shared use of a telephone line is that the emergency call unit will not work if the telephone is in use, or if the handset of the telephone is left "off the hook". The users of emergency call units as aforesaid i.e. the elderly, infirm or disabled, experience one particularly acute problem with the telephone. Although there is generally no particular requirement for a telephone user wishing to make an outgoing call to reach the telephone instrument and perform the required dialling or other operating functions within a limited time interval, the time available for answering an incoming call is always restricted to the length of time the caller is prepared to wait for the called party to reply. This duration will vary between callers, between circumstances in which the call is made, and according to numerous other imponderable factors. Reaching a ringing telephone and answering it before the caller "rings off" is thus often a serious problem for the elderly or infirm. The object of the invention is to solve the aforementioned problem. Disclosure Of Invention According to the present invention we provide a call unit for use in an emergency call system, the unit comprising having speech receiving and transmitting means capable of operating in a handsfree mode, an automatic dialler, a first non-volatile memory capable of storing at least a first set of information that determines the destination of an emergency call made from the unit, operating means which in normal mode is responsive to a control signal from a control signal generator located remote from the unit to initiate autodialling to the emergency call destination via a telephone line to which the call unit is connected, and means enabling handsfree two-way speech communication between the call unit and the emergency call destination once telephonic connection has been established therebetween, in which the call unit includes switch means having a first normal switching condition in which the operating means is enabled to operate in said normal mode, said switch means being responsive to an incoming call signal on the telephone «line to adopt a second switching condition in which the operating means is enabled to operate in a receive mode, wherein on receipt of a control signal from the control signal generator the operating means enables handsfree two- way speech communication between the .call unit and the incoming caller. The advantage of this arrangement for an elderly or an infirm subscriber will be immediately apparent. If a telephone call is made to the subscriber the call unit will transmit an audible tone in the usual way, and answering of the call can then be initiated merely by the generation of a control signal at a location remote from the unit. Handsfree two-way telephonic communication by way of the loudspeaker/microphone unit is then enabled and the call can proceed normally without the subscriber having had to reach the call unit. In the absence of an incoming call, generation of the control signal will initiate an emergency call. The operating means may comprise a receiver for a remotely generated radio, infrared, ultrasonic or other control signal not requiring wire for its transmission, and means responsive to a signal received at the receiver. The control signal generator may then be fully portable so that it may be carried by the subscriber or left closely adjacent to the subscriber at all times. Alternatively the control signal generator may be a switch remote from the call unit but connected thereto by wires. A plurality of . such switches could be located at strategic points in a dwelling. The operating means may be such that it will respond to all control signal generators when in the normal mode, but only to one or more control signal generators when in the receive mode. According to a second feature of the invention a call unit for use in an emergency call system comprises speech receiving and transmitting means capable of operating in a handsfree mode, an automatic dialler, a first non-volatile memory capable of storing at least a first set of information that determines the destination of an emergency call made from. the unit, operating means which in normal mode is responsive to a control signal from a control signal generator located remote from the unit to initiate autodialling to the emergency call destination via a telephone line to which the call unit is connected, and means enabling handsfree two-way speech communication between the call unit and the emergency call destination once telephonic connection has been established therebetween, a second non-volatile memory capable of storing at least a second set of information that determines the destination of a normal, non-emergency, telephone call made from the unit, and the operating means, when enabled to operate in said normal mode, operates on receipt of a control signal to initate a call to the emergency call destination in accordance with the first set of information if said first set of information is present in said first memory, or, if said first set of information is absent from said first memory to initiate a call to the normal call destination. Short-code dialling systems are now conventional in telephones, numbers to be dialled being stored in a non- volatile memory and being recallable from that memory by operation of one or two buttons on the telephone to initiate a dialling function. This feature of the invention makes use of the facility in the event that an emergency contact number has not been programmed into the first non-volatile memory or that somehow it has been lost therefrom. Under these circumstances, if an emergency call is initiated that call will automatically be routed to a number stored in the second memory. If the second memory contains a plurality of numbers, then the programming will be such that the number chosen is the highest priority, number in that memory. Brief Description Of Drawings Figure 1 is a block diagram of a unit according to the invention. Figure 2 shows a plan view of a call unit. Mode For Carrying Out The Invention Figure 1 shows a call unit 1 connected to the public switched telephone network 4 by way of which calls may be made to an emergency call receiving station 2 or to any ordinary subscriber telephone 3. The call unit incorporates a controlling microprocessor 9, and in addition embodies a radio signal receiver 7, an automatic dialler 8, a non-volatile memory 10, a loudspeaker and microphone unit 11, a handset 12, a voice switching unit 13, a keypad 14, a call switch 15, a ring detect unit 16 having a first normal switching condition, a line switch 17, a tone ringer 18, and a tone signaller 19. The construction of the individual units is immaterial to the invention, and suitable units will be familiar to those skilled in the art. The unit also has associated therewith one or more sensors 5 which may include, for example, a manually operated switch or switches mounted on the unit or remote therefrom, together with environmental detectors, such as a smoke detector. Also associated with the unit is a control signal generator comprising a radio signal transmitter 6, in a form that may conveniently be carried on the person of a subscriber or kept closely adjacent to the subscriber. For example, a push-button operated transmitter unit may be worn on a cord around the neck of the subscriber. The memory 10 is divided into two sections, a first section 10a storing information concerned with the emergency call function of the unit and containing the emergency telephone number or numbers and unique identification code of .the unit, and a second section 10b capable of storing telephone numbers for normal, non- emergency use, which numbers may be programmed into the unit by the subscriber through the medium of the keypad. Non-volatile memory is used in each of the two sections, for example a serial EARGM such as the ER 1400, manufactured by General Instrument Corporation in the U.S.A. The telephone numbers stored in the second section 10b of the non-volatile memory may be subsequently recalled f om that memory by operation of one or two buttons on the keypad 14 and will cause that number to be applied to the automatic dialler 8. Referring to Figure 2 , three dedicated keys 20 are provided on the front panel of the call unit, the operation of any one of which will cause the unit to automatically dial the telephone number that has been assigned to that key. For example, one key may contain the telephone number of the subscriber's doctor, the second the phone number of a close relative and the third that of a friend. Each dedicated telephone number may be up to 16 digits, and can be dialled automatically in the normal handset mode by lifting the handset and pushing the required single button. Alternatively, the handset may be left on the hook and the call switch 15 pressed, followed by the required single dedicated button, thus enabling handsfree mode operation by the subscriber. In addition to the three dedicated telephone numbers . stored in memory, a repertory dialling facility may also be provided, that allows up to eight phone numbers of up to 16 digits to be stored internally in the second section 10b of the non-volatile memory. These can be dialled automatically using a two key sequence, in accordance with well known technology in this field. One of the stored dedicated numbers will be assigned the highest priority, for example that programmed into* section 10b of the memory and associated with one of the keys 20 or with keypad numeral 1. The principal operating mode of the unit is that of . readiness to make an emergency call if required. An mergency call is initiated by operation of any one of the sensors 5, e.g. a ceiling mounted pull switch, or by . operation of the radio signal transmitter 6. In order to reassure the subscriber that an emergency call has been raised, initially a call progress light 21 on the call unit will flash and a reassurance tone will sound from the speaker. During this period the alarm may be reset using a reset switch (not shown) on the rear of the unit, so aborting the call and returning the call unit to standby mode. If, after the pre alarm period, no reset has occurred then a signal is applied to the microprocessor 9, which calls from the first section 10a of the memory 10 the number to which an emergency call should be routed. That number is applied to the automatic dialler which, via the public switched telephone network, calls the receiving station 2. An operator at the receiving station manages a control unit and is suitably equipped to answer incoming emergency calls and to arrange assistance for the subscriber. When a call is received at the receiving station the public switched telephone network line is looped and a handshaking routine exchanged between the receiving station and the call unit. The handshake signals are received and decoded . at the call unit by the tone signaller 19. Once this has been effected the microprocessor of the call unit transmits from the first section 10a of the memory, via the tone signaller, information coded appropriately for transmission over the public switched telephone network, which information indicates at least the identity of the unit from which the call has originated and the method of originating the call. Thus, distinction may be made between manual operation by a manually operated switch forming one of the sensors 5 or by radio transmitter 6, between operation by an environmental sensor and between operation by an inactivity monitor if no activity within the subscriber's dwelling has been detected for a set period. Speech communication is then effected between the receiving station and the call unit, transmission being by way of the speaker and microphone unit 11 in the call unit and typically being in half duplex mode with direction under control of the operator at the receiving station. On completion of the cali, the operator at the receiving station then clears down the call by sending tones to the subscriber's call unit, which causes opening of the line switch 17. The call unit will now return to its standby state, either ready to raise an emergency call, or to receive an ordinary incoming telephone call. If, however, no cleardown signal is sent, a fail safe timer is provided in the call unit which opens the line switch after a predetermined time interval, for example five minutes. If required, the first section 10a of the memory may also be programmed to contain a second emergency telephone number that is used by the microprocessor to initiate automatic dialing to the second number if a call to the principal emergency number should fail for any reason. If the alarm autodialling mode thus far described is activated and no emergency numbers have been programmed into the first section 10a of the non-volatile memory of the call unit, then the microprocessor will interrogate the second area 10b of memory, and the unit will attempt to dial the number associated with the first dedicated key. If no such number has been entered then the call unit will emit a warning tone and the call progress light will remain on until reset. If this dedicated number has been entered, then the call unit will dial it and open up a direct speech path in a handsfree mode. No attempt will be made to establish whether a successful connection has been made and the handshaking and unit identification protocols will not be used. The call will be cleared automatically after a preset time. It will be appreciated that any outgoing calls will be overriden from the call unit 1 upon operation of the radio trigger 6, or operation of one of the sensors 5, for example a ceiling mounted pull switch. The secondary operating mode of the unit is as a conventional telephone. The handset is lifted and the line checked for a dial tone. The required number is then entered using full or repertory dialling from the keypad and a connection established. Termination of the call can take place at any stage by replacing the handset. In addition, one of the three dedicated keys 20 may be used, by first lifting the handset and then pressing the relevant dedicated key. Handsfree mode can be used on outgoing calls merely by pushing the call switch 15 without lifting the handset. All the dialling procedures available when using the handset are also available in the handsfree mode. Outgoing calls can also be transferred to the handset by lifting it. When in the handsfree mode half-duplex speech communication takes place by way of the loudspeaker/microphone unit 11, speech direction being controlled by the voice switching unit 13. When a call to the unit is dialled by way of the public switched telephone network from a remote telephone 3, the ringing current on the telephone line causes the tone ringer 18 to sound. The ringing current is also detected by a ring detector unit 16 which changes from its normal switching condition to a second switching condition and sends a signal to the microprocessor 9, which may if required disable any selected one of the sensors 5. If the call is now answered by simply lifting the handset 12 this fact is registered and the microprocessor causes the line switch 17 to close, so completing a communication path through the handset. When the call is finished the handset is replaced and the microprocessor returns all elements to their normal standby condition. Alternatively, rather than lift the handset, answering of the incoming call may be initiated simply by operating the radio transmitter 6. The signal received therefrom by the receiver 7 is passed to the microprocessor 9, which has been enabled by the second switching condition of the ring detector unit 16 to control closing of the line switch 17 and thus enable the voice switching unit 13 so opening a speech path to the loudspeaker and microphone unit 11. Hands-free communication is thus established through the loudspeaker and microphone unit, the tone ringer stops sounding and the subscriber can then conduct a conversation with the caller. Operation of the radio signal transmitter 6 to answer the call also changes the state of the microprocessor to one in which the next operation of the radio signal transmitter will open the line switch 17 to terminate the call, enable any disables sensors 5 to return the call unit to its normal state of alarm call readiness, and return the radio signal transmitter and receiver to their alarm raising function. Hence, on finishing the conversation, the subscriber simply operates the radio transmitter again, so causing a return to the alarm standby state. Thus, handsfree mode can be entered on incoming calls simply by . pressing the transmitter trigger when the ringing is heard, the call being terminated simply by pressing the trigger again. The user need not be physically present at the call unit itself. When in the handsfree mode it is desirable that the call progress light will remain on. In addition to using the transmitter to control answering of an incoming call, such call may be answered by any one of the sensors 5 which have not been disabled. This has the advantage in situations where the person is not able to reach the radio transmitter, or the call unit handset, but is situated in the near vicinity of a sensor, e.g. a ceiling mounted pull switch. Although the foregoing description has been written in terms of a radio signal transmitter and receiver for control purposes, it will be appreciated that other types of control signal, for example, infrared or ultrasonic may alternatively be used. Industrial Applicability The advantage to an elderly or infirm person of being able to initiate receipt of an incoming telephne call from a remote location will be immediately apparent. Furthermore, the use of a single radio transmitter for initiating such answering, or for giving an alarm call, is highly advantageous as the subscriber has only one single instrument to operate and will not have the problem of selecting the correct instrument if in a confused state of mind.

Claims: CLAIMS 1. A call unit for use in an emergency call system, the unit comprising speech receiving and transmitting means capable of operating in a handsfree mode, an automatic dialler, a first non-volatile memory capable of storing at least a first set of information that determines the destination of an emergency call made from the unit, operating means which in normal mode is responsive to a control signal from a control signal generator located remote from the unit to initiate autodialling to the emergency call destination via a telephone line to which the call unit is connected, and means enabling handsfree two-way speech communication between the call unit and the emergency call destination once telephonic connection has been established therebetween, in which the call unit . includes switch means having a first normal switching condition in which the operating means is enabled to operate in said normal mode, and responsive to an incoming call signal on the telephone line to adopt a second switching condition in which the operating means is enabled to operate in a receive mode wherein on receipt of a control signal from the control signal generator the operating means enables handsfree two-way speech communication between the call unit and the incoming caller. 2. A call unit according to claim 1 in which the operating means when in said normal mode is capable of . responding to a control signal from any one of a plurality of emote control signal generators. 3. A call unit according to claim 2 in which the operating means when in said receive mode is capable of responding to a control signal from at least one selected remote control signal generator, but not from at least one. other remote control signal generator. 4. A call unit according to claim 1 in which the operating means when in said normal and said receive mode is capable of responding to a control signal not requiring wire for its transmission. 5. A call unit according to claim 4 in which the control signal is a radio signal and the operating means includes a radio receiver for said signal. 6. A call unit according to claim 1 in which said switch means is a unit capable of detecting a ringing signal on the incoming telephone line, and of adopting said second switching condition on detection of said ringing signal. 7. A call unit according to claim 1 in which said operating means comprises a microprocessor. 8. A call unit according to claim 1, and including a second non-volatile memory capable of storing at least.a second set of information that determines the destination of a normal, non-emergency, telephone call made from the unit, and the operating means, when enabled to qperate in said normal mode, operates on receipt of a control signal to initiate ' a call to the emergency call destination in accordance with said first set of information if said first set of information is present in said first memory, or, if said first set of information is absent from said first memory, to initiate a call to the normal call destination. 9. A call unit according to claim 8 in which said second set of information comprises a plurality of telephone numbers each for a respective normal call destination, said numbers each have a priority allocation, and said operating means initiates said normal destination call to the number with the highest priority allocation. 10. A call unit according to claim 8 in which the unit includes a manually operable keypad by way of which said second set of information may be entered into said second memory.

Inventors: JONES DAVID, PINDER RUSSELL STUART, JONES, DAVID, PINDER, RUSSELL, STUART
Applicants: TUNSTALL TELECOM LTD, TUNSTALL TELECOM LIMITED
Application year: 1985
Main classification: H04M11
IPC codes: H04M11