Abstract:
Emergency call system which enables an individual to summon assistance includes an emergency call unit connectable to a telephone line, at least one remote speakerphone unit having a speakerphone and connectable to the same telephone line as the emergency call unit, and at least one pendant adapted to be worn by the individual and including a button. The emergency call unit is arranged to determine whether any remote speakerphone units are off-hook when the button on the pendant is actuated and if so, send a signal to each remote speakerphone unit to disconnect from the telephone line. If one of the remote speakerphone units is off-hook, it will not interfere with the functioning of the emergency call unit. The emergency call unit is also arranged to dial a predetermined emergency telephone number when the button on the pendant is actuated and the telephone line is available for an outbound call.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to arrangements and methods for controlling and using speakerphones associated with telephones. 
         [0002]    The present invention also relates generally to emergency call systems, and in particular, to emergency call systems for aiding persons in distress, for example, due to medical, fire, burglary or other emergencies. 
       BACKGROUND OF THE INVENTION 
       [0003]    Nowadays, a vast majority of telephones include a speakerphone which allows for hands-free use of the telephone. When the speakerphone is activated, e.g., by pressing a button on the telephone, a user can talk and listen over the telephone line so long as the user remains within the reception or talking range of a microphone associated with the telephone and within the listening range of the speakerphone. If the user moves out of the reception range, although they can speak, the other party to the call will not be able to hear the user. Similarly, if the user moves out of the listening range, the user will not be able to hear the other party to the call. 
         [0004]    If the user then walks into a room with a similar telephone equipped with a speakerphone and microphone, the user will have to press a button on this telephone in order to join the call. Thus, as the user walks around a home or office having multiple telephones, the user will have to individually activate each speakerphone in order to enable its use. 
         [0005]    It would therefore be desirable to provide a speakerphone control technique for use with multiple telephones having speakerphones which allows a user to walk through a home or office while conducting a telephonic conversation with another party without having to individually activate each and every speakerphone in the home or office. 
         [0006]    Emergency call systems are known in which a person in distress can get immediate help. Specifically, in such systems, the person presses a button on a remote emergency pendant which transmits a signal to an alarm in the person&#39;s house. The alarm then sends a signal to a central station, and a person at the central station must then dial the telephone numbers from a prescribed list in order to obtain aid for the distressed person. 
         [0007]    However, such an arrangement is relatively complicated and costly. Specifically, such an arrangement operates in a similar manner to a central burglar or fire alarm in a house, and requires a separate, complicated wiring assembly for the house, at a considerable cost. Also, such a system requires that a central station be provided, and therefore, the subscriber to such a system must pay a monthly fee for such service, adding further to the cost of the system. 
         [0008]    Also, a problem with known systems is that if a central station, upon calling a telephone number for aid, continuously receives a busy signal, the central station may stop calling after a number of attempts, so that the person in distress does not receive aid. 
         [0009]    Emergency call systems have therefore been invented which are connected to the telephone line and enable a caller to automatically call a plurality of other parties to leave an emergency message, sometimes, simply by pressing a button. 
         [0010]    Examples of such emergency call systems are disclosed in U.S. Pat. Nos. 6,212,260 and 6,614,883, incorporated by reference herein, wherein the emergency call systems include an emergency call unit having a memory for storing telephone numbers to be called and an emergency message, an emergency key, and a microprocessor for controlling, among other things, storage of the telephone numbers and emergency message in the memory, dialing of the telephone numbers in sequence upon activation of the emergency key, and transmission of the emergency message to the dialed telephone number to automatically advise of an emergency. 
         [0011]    Such emergency call systems can also be equipped to enable the user in need of assistance to talk to the called party via a speakerphone on the emergency call unit. 
         [0012]    If an emergency call system includes both a remote emergency pendant and an emergency call unit, when faced with an emergency situation, the user can depress a button on the emergency call unit or a button on the pendant to summon help so that the emergency call unit will automatically connect to the telephone line and dial a predetermined set of telephone numbers. There are thus two different ways to summon assistance, depending on the user&#39;s proximity to the emergency call unit, i.e., if the user is far from the emergency call unit, they can press the button on the pendant while if they are close, they can press the button on the emergency call unit. In at least the latter case, the speakerphone will automatically be activated to allow the user in the emergency situation to converse, if possible, with a called party via the speakerphone. However, note that use of the speakerphone is only possible when the person in the emergency situation is in the same room or in the general vicinity of the emergency dialer. 
         [0013]    By contrast, the emergency pendant can transmit an emergency request from distances of over 100 feet. So while aid can be summoned from a greater distance using the remote emergency pendant, the person summoning help will not be able to converse with a called party from such a distance. Further if an extension telephone is off-hook, the emergency call unit will not be able to place any emergency calls since it cannot gain control of the telephone line. 
         [0014]    It would therefore be desirable to provide an emergency call unit which overcomes the deficiencies described above in that it allows an emergency speakerphone dialer system to be configured to permit communication between the called party and the person placing the emergency call, and allow emergency calls to be placed even when an extension telephone is off-hook. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0015]    Accordingly, it is an object of the present invention to provide emergency call systems that eliminate deficiencies of prior art emergency call systems described above. 
         [0016]    It is another object of the present invention to provide new and improved emergency call units which permit communication between the called party and the person placing the emergency call. 
         [0017]    It is still another object of the present invention is to provide new and improved emergency call units which allow emergency calls to be placed even when an extension telephone is off-hook. 
         [0018]    It is yet another object of the present invention to provide new and improved techniques to control speakerphones associated with telephones. One such technique allows simultaneous activation of the speakerphone of multiple telephones situated throughout a home or office so that a user can walk throughout the home or office and use the closest speakerphone to participate in the telephonic conversation. 
         [0019]    In accordance with one aspect of the present invention, a speakerphone control system includes a pendant adapted to be worn by the individual and including one or more response mechanisms for responding to a user&#39;s action and a plurality of speakerphone units coupled to a common telephone line and adapted to be arranged throughout a structure with partially overlapping or non-overlapping listening and talking ranges. Each response mechanism is arranged to convert the user&#39;s action into signals receivable by the speakerphone units to cause selected ones of the speakerphone units to activate their speakerphones such that when the speakerphone units are activated and a call is in progress on the telephone line, the user can interact with different speakerphone units. 
         [0020]    The response mechanism may be one or more depressible buttons, a microphone and a voice-recognition circuit coupled thereto and combinations of the same. The response mechanism can be arranged to answer an incoming call or initiate an outgoing call based on the user&#39;s action. 
         [0021]    An emergency call system in accordance with the invention which enables an individual to call for or summon assistance when desired includes an emergency call unit adapted to be connected to a telephone line, at least one remote speakerphone unit having a speakerphone and adapted to be connected to the same telephone line as the emergency call unit, and at least one pendant adapted to be worn by the individual and including at least one button. The emergency call unit is arranged to determine whether any of the remote speakerphone units are off-hook when a button on the pendant is actuated and if so, send a signal to each remote speakerphone unit to disconnect from the telephone line. In this case, if one of the remote speakerphone units is off-hook, it will not interfere with the functioning of the emergency call unit. The emergency call unit is also arranged to dial a predetermined emergency telephone number when the button on the pendant is actuated and the telephone line is available for an outbound call. 
         [0022]    The emergency call unit may be arranged to send a signal to each remote speakerphone unit to activate its speakerphone while or after it dials the predetermined emergency telephone number. This allows the individual to hear the outbound dialing and communicate with the called party once the call is answered from any of the remote speakerphone units. 
         [0023]    The emergency call unit may also be arranged to send a signal to each remote speakerphone unit to disable a keypad thereon at least while the emergency call unit dials the predetermined emergency telephone number. 
         [0024]    The emergency call unit may also be arranged to send a signal to each remote speakerphone unit to deactivate its speakerphone after the emergency call unit completes a call to the predetermined emergency telephone number. 
         [0025]    In one configuration, each remote speakerphone unit is associated with a respective pendant. In another configuration, only one pendant is provided and communicates only with the emergency call unit. 
         [0026]    Another embodiment of an emergency call system for enabling an individual to call for assistance which may be incorporated into the emergency call system described above or used independent therefrom includes a pendant adapted to be worn by the individual and including at least one button and a communications unit having a speakerphone and being arranged to enable communications. The communications unit is arranged to activate and deactivate the speakerphone upon actuation of a button on the pendant. The communications unit may also be arranged to activate the speakerphone upon one depression of the first button and deactivate the speakerphone upon a subsequent depression of that button. In this case, the communications unit may also be arranged such that upon the subsequent depression of the first button, it deactivates the speakerphone even when the associated handset is removed from engagement with the communications unit. 
         [0027]    This embodiment is particularly useful in a situation where another telephone unit is connected to same telephone line as the communications unit whereby the communications unit is arranged such that actuation of the button connects the speakerphone to the telephone line when the telephone unit is in use. 
         [0028]    Another embodiment of an emergency call system in accordance with the invention which may be incorporated into the emergency call systems described above or used independent therefrom includes an emergency call unit adapted to be connected to a telephone line, an extension telephone, and an over-ride accessory for connecting the extension telephone to the same telephone line as the emergency call unit. The over-ride accessory communicate with the emergency call unit, e.g., via an RF transmission arrangement, and connects or disconnects the extension telephone from the telephone line based on signals from the emergency call unit. Thus, the emergency call unit includes a transmission portion or component for transmitting a command signal indicative of whether the over-ride accessory should connect or disconnect the extension telephone from the telephone line and the over-ride accessory including a receiving portion or component for receiving the command signal from the transmission portion or component. The emergency call unit may be arranged to transmit the command signal upon a determination that an outbound call cannot be made on the telephone line. 
         [0029]    The above and other objects, features and advantages of the present invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals identify like elements, and wherein: 
           [0031]      FIG. 1  is an illustration of a building showing the manner in which a speakerphone control technique is used in accordance with the invention; 
           [0032]      FIG. 2  is a schematic of a first embodiment of an emergency call system according to the present invention; 
           [0033]      FIG. 3  is a schematic of a second embodiment of an emergency call system according to the present invention; 
           [0034]      FIG. 4  is a schematic of a third embodiment of an emergency call system according to the present invention; 
           [0035]      FIG. 5  is a schematic of a fourth embodiment of an emergency call system according to the present invention; and 
           [0036]      FIG. 6  is a schematic of a pendant for use in an emergency call system according to the present invention. 
           [0037]      FIG. 7  is a schematic of another configuration of an emergency call system in accordance with the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]    Referring first to  FIG. 1 , a speakerphone technique in accordance with the invention allows a user in a home or office  10  to receive an incoming call and/or place a call with only a single depression of a button  12  on for example, a pendant  14 , while providing use of multiple speakerphone units  16 . That, by pressing button  12 , the user can activate a plurality of speakerphone units  16  distributed through the home or office  10 , for example, one in each room, and participate in a telephonic conversation using the speakerphone units  16  while the user is walking throughout the home or office  10 . Although in this embodiment and other embodiments described below mention that one or more buttons are situated on a pendant, it is envisioned that in addition to or as an alternative to one or more buttons on a pendant, one or more buttons can be arranged on the speakerphone units  16 , for example, either on the base or handset thereof. Such buttons would perform the same functions as the button(s) on the pendant, described more fully below. 
         [0039]    Housed in pendant  14  is an electronic mechanism which converts the pressing of the button  12  into an electronic signal designed to activate one or more of the speakerphone units  16 . The design and construction of this electronic mechanism, as well as an electronic mechanism in each speakerphone unit  16  to receive the signal from the pendant&#39;s electronic mechanism, would be readily ascertainable by one skilled in the art. 
         [0040]    As used in the description of  FIG. 1 , a speakerphone unit  16  is a telephone which has a speakerphone feature and also includes a microphone to thereby enable the user to participate in the conversation, listening and talking, without having to handle the telephone or a handset thereof. 
         [0041]    This is possible provided the user is always within range of one of the speakerphone units  16  while they walk around the home or office  10 . When the speakerphone units  16  are those having sensitive speakerphones, such as a ClearVoice model sold by Telemergency, Ltd., then the user can be 20 feet or more away from the speakerphone unit  16  and still the speakerphone unit  16  will pick up the user&#39;s speech. For the user to hear the voice of the other party through the speakerphone, the volume setting of the speakerphone units  16  can be adjusted as necessary to ensure the user can hear, not only the other party but also preferably an incoming ring, at any location throughout the home or office  10 . The number of speakerphone units  16  needed to ensure complete coverage through the home or office  10  depends, for example, on the model of speakerphone unit  16  used and the configuration and size of the home or office  10 . 
         [0042]    In use, a user would press button  12  when he or she hears an incoming ring tone. In one user-settable implementation, the incoming ring tone is activated on each speakerphone unit  16  while another setting would allow for generation of the incoming ring tone on only selected ones of the speakerphone units  16 , on only a single speakerphone unit  16 , or on only the speakerphone unit  16  closest to the user&#39;s current location. The user can activate this selectivity feature to limit the areas of the home or office  10  in which this technique can be applied. 
         [0043]    Once button  12  is pressed, the selected speakerphone unit(s)  16  would be activated simultaneously (i.e., when each receives the electronic signal generated upon depressing button  12  on pendant  14 ) and connected to the telephone line to allow the user to talk in the vicinity of any selected speakerphone unit  16  and have their voice be received by that speakerphone unit  16 . They would also hear the calling party&#39;s voice which would be generated at the selected speakerphone unit(s)  16 . 
         [0044]    Thus, an incoming call can be picked up on a single speakerphone unit  16  and the other speakerphone units  16  connected to the same telephone line can be joined into the call. The same ability to enable multiple parties to participate in a conversation on a single telephone line using multiple speakerphone units  16  or the handsets  16 B thereof can be applied to an outgoing call made from one of the speakerphone units  16 . Both techniques can be achieved once a phone call is in progress using one of the speakerphone units  16  or a handset thereof by pressing a button  16 A on the speakerphone unit  16 , or a button on the handset of the speakerphone unit  16  or a button on a pendant. 
         [0045]    A result of the use of the speakerphone technique described above, in which selected ones or all of the speakerphone units  16  in a home or office  10  are simultaneously activated, is that multiple users can participate in the same telephone call even when situated in different parts of the home or office  10  and using different speakerphone units  16 . Thus, one person in room  18  and another person in room  20  in home or office  10  can all participate in a conversation, i.e., a conference call. This can all be done simply by pressing button  12  on pendant  14 . 
         [0046]    To make an outgoing call, the user would dial the number at one of the speakerphone units  16  and then depress button  12 . Thus would join all speakerphone units  16  to the outgoing call. When the called party answers, the user can then freely walk around the home or office and converse with the called party. 
         [0047]    An additional design of the speakerphone units  16  described above allows for use of the speakerphone units  16  as an intercom system. Since the speakerphone units  16  would typically be placed throughout a home or office, it would be highly conducive for use as an intercom system. In such a system, a user would press button  12  when he or she hears wants to activate the intercom and communicate with someone else in the home or office, who might be situated at a distance from the user. In one scenario, button  12  activates all of the speakerphone units  16  whereas in other implementations, multiple buttons can be provided on pendant  14  and each activates a different group or overlapping group of speakerphone units  16  (described more fully below). Once button  12  is pressed, the selected speakerphone unit(s)  16  would be activated simultaneously (i.e., when each receives the electronic signal generated upon depressing button  12  on pendant  14 ) and allow the user to talk in the vicinity of any selected speakerphone unit  16  and have their voice be received by any other activated speakerphone unit  16  (as an intercom system). They in turn would hear the voice of other users talking into other speakerphone units  16 . 
         [0048]    The outgoing telephone line is bypassed during intercom use, and the telephone handsets may even be off-hook without interfering with the intercom system. However, the internal wiring of the speakerphone units  16  in the home or office is used for the intercom. As a result, any incoming sounds, such as a busy signal, must be filtered out so that they do not interfere with the conversations. To this end, a filter can be incorporated into the speakerphone units  16  to filter such noise, e.g., noise indicative of an inactive telephone sent by the telephone company. Alternatively, and for those situations when the telephone company sends a voice message about an inactive telephone, a designated button can be provided on the speakerphone units  16  which can be pressed to activate the intercom mode and cause a signal to be transmitted over the telephone line, e.g., every 5-15 seconds, to delay reception of a signal from the telephone company indicative of an inactive telephone. Such a signal can be the same as the signal generated when one of the telephone buttons is pressed since this will delay the generation of an inactive telephone signal as the telephone company is thereby caused to think an outgoing call is in progress. The user can also press one of the buttons every 5-15 seconds for the same effect. 
         [0049]    A result of the use of the speakerphone technique described immediately above, in which selected ones or all of the speakerphone units  16  in a home or office  10  are simultaneously activated, is that multiple users can participate in the same conversation even when situated in different parts of the home or office  10  and using different speakerphone units  16 . Thus, one person in room  18  and another person in room  20  in home or office  10  can all participate in a conversation by implementing the intercom system option. This can all be done simply by pressing button  12  on pendant  14 . 
         [0050]    A variation on the intercom system allows a person to use the handset  16 B of a speakerphone unit  16 , i.e., they would not have to use the speakerphone and microphone capabilities of the speakerphone unit  16 . Rather, the person picks up the handset  16 B and presses a button  16 A on the speakerphone unit  16  (which could also be arranged on the handset  16 B itself) and the speakerphone unit  16  bypasses the telephone line and activates the other speakerphone units  16  to provide for intercom use via the handset  16 b and the speakerphone units  16 . Note that if the handset is cordless, then both the handset of the speakerphone unit  16  and the base of the speakerphone unit may be part of the intercom network. 
         [0051]    In the embodiment described above, pendant  14  includes a button  12  to activate the selected speakerphone unit(s)  16 . Alternatively, pendant  12  can include multiple buttons with each being designated to activate one or more of the speakerphone units  16 . When multiple buttons are provided, different combinations of buttons can activate different sets of speakerphone units  16 . Markings as to which buttons or combination of buttons activate which speakerphone unit or units can be provided on the pendant. Moreover, one or more buttons may be designated to call a respective predetermined telephone number so that by simply pressing a button having a desired designation, a command is sent to a speakerphone unit  16  to initiate a call to the predetermined telephone number and some or all of the speakerphone units  16  are activated. 
         [0052]    When a single button  12  is provided on a pendant  14 , pendant  14  can be designed with appropriate electronics to cause one depression of button  12  to activate the selected speakerphone unit(s) and a subsequent depression of the button  2  to deactivate the speakerphone unit(s)  16 . Alternatively, a second button can be provided in which case, one button is designated for activating the selected speakerphone unit(s)  16  and the other button is designated for deactivating the selected speakerphone unit(s)  16 . 
         [0053]    Instead of one or more buttons, pendant  14  may include a microphone  22  which allows for voice-recognition in order to generate the electronic signal to be sent to the speakerphone unit(s)  16  to cause their remote activation. When the user speaks a word, a voice-recognition circuit in the pendant  14  would recognize it and then causes activation of the selected speakerphone unit(s)  16 . Different voice commands can be designated by the user, e.g., via programming of the voice recognition circuit, to activate one or more of the speakerphone units  16  or different sets of speakerphone units  16 . 
         [0054]    Instead of one or more buttons or a voice-recognition circuit, any other type of user response mechanism which is designed or programmed to respond to an action by the user may be used in accordance with the invention. 
         [0055]    Any of the speakerphone control techniques described above can also be implemented in combination with an emergency call system whereby depressing a button designated “Emergency” or saying “Emergency” causes the activation of all speakerphone units  16  as well as initiation of an outgoing call to a pre-determined telephone number (a telephone number to be called in case of an emergency). Pressing the button or saying the emergency condition word will thereby allow the user to communicate with the called party so long as the user is within range of any one of the speakerphone units  16 . 
         [0056]    Referring now to  FIG. 2 , a first embodiment of an emergency call system in accordance with the invention is designated generally as  30  and includes a communications unit  32  having a speakerphone  34  which can be activated by a remote pendant  36 . A call can be placed from the communications unit  32 , and if desired the speakerphone  34  can be activated by depressing a designated emergency button  38  on the unit  32  itself or by depressing a button  40  on the pendant  36 . 
         [0057]    It is important to appreciate that this system is not necessarily an emergency dialer in that there are no stored emergency call numbers that can be called as part of a predetermined dialing sequence when either button  38  on the communications unit  32  or button  40  on the pendant  36  is pressed. Rather, this emergency call system  30  is essentially a standard speakerphone whose speakerphone operation can be controlled by a pendant that can transmit commands to the communications unit  32  to turn the speakerphone  34  on and off. To this end, any conventional transmission and reception arrangement could be used with the transmitter portion of this arrangement being residence in the pendant  36  and activated upon depression of button  40  and the receiver portion being resident in the communications unit  32  and coupled to the speakerphone  34  to activate it, e.g., via an electronic coupling. 
         [0058]    Further, it is possible that a telephone call can be placed from a different telephone (other than the handset  42  associated with communications unit  32 , and the communications unit  32  can be connected to that call using its speakerphone by depressing a button  40  on the pendant  36 . That is, when a call is in progress on the telephone line with which the communications unit  32  is connected, the user can press button  40  on pendant  36  and join that call in progress and converse with the participants to that call using speakerphone  34 . 
         [0059]    It is possible to design the electronic control system in the communications unit  32  so that depressing the button  40  on the pendant  36  a second time (as detection via the receiver portion of the transmission arrangement coupling the pendant  36  to the communications unit  32 ) will cause the communications unit  32  to hang-up, i.e., disconnect or terminate usage of the speakerphone  34 , even if the built-in handset  42  is removed from its cradle on the emergency call unit  30 . This unique feature allows the user to place a call using the handset  42 , remotely activate the speakerphone  34 , and hang-up using the remote pendant  36  without replacing the handset  42  in its cradle. Therefore, communications unit  32  cannot tie up the telephone line even if the handset  42  is not replaced in its cradle. 
         [0060]    Another embodiment of an emergency call system in accordance with the invention is shown in  FIG. 3  and designated generally as  44 . This embodiment is particularly useful for users who do not desire to use the special remote speakerphone unit described above, and desire audio communication at additional locations in the area. This embodiment provides for an “over-ride” accessory  46  that can be used with a standard telephone to essentially disconnect the telephone from the telephone line when an emergency request is made by the main emergency speakerphone unit. 
         [0061]    Over-ride accessory  46  is placed between an extension telephone  48  and a telephone jack  50  connecting to the telephone line. Installation of accessory  56  involves removing the cord of the extension telephone  48  from the telephone jack  50  and plugging it into the accessory  46  which is then plugged into the jack  50 . The over-ride accessory  46  is equipped with a means of receiving a signal, typically an RF communication, from the main emergency call unit  52  having a speakerphone  54  that can be used to connect and disconnect the extension telephone  48  from the telephone line. Emergency call unit  52  may include features described in U.S. Pat. Nos. 6,212,260 and 6,614,883 and U.S. patent application Ser. No. 11/356,519 filed Feb. 17, 2006, incorporated by reference herein. 
         [0062]    Thus, over-ride accessory  46  includes a receiver component  56  of a communications arrangement with the transmitter portion or component  58  of the communications arrangement being resident in, for example, the emergency call unit  52 . 
         [0063]    When the emergency call unit  52  is commanded to place calls to the stored telephone numbers, it must seize control of the telephone line so that it can place telephone calls. If it is determined that the line is busy, either a telephone was inadvertently left off-hook or someone is on a call, it will transmit a signal to the over-ride accessory  46  to disconnect the extension telephone  48  from the telephone line. The emergency call unit  52  will then take control of the telephone line, and dial the first number. 
         [0064]    Once the emergency call unit  52  has control of the telephone line, it could reconnect the extension telephone  48  to the telephone line and begin the dialing process. However, note that keys pressed on an extension telephone could interfere with the dialing process, and the desired emergency telephone numbers may not be dialed properly. Therefore, as an alternative, the extension telephone may be disconnected from the telephone line until a telephone number has been dialed successfully. 
         [0065]    An over-ride accessory  46  could be placed between each extension telephone  48  and the telephone jack  50  to which the extension telephone  48  is connected. 
         [0066]    By using one emergency call unit having a speakerphone and one or more remote speakerphone units (and/or standard extension telephones with over-ride accessories), it becomes possible to configure an emergency call system that not only affords emergency protection for the user, but also provides a means of possible communication with the called parties from other rooms and locations throughout, e.g., a home or apartment (when special remote speakerphones are used). In addition, any extension telephone that is off-hook cannot prevent an emergency call from being placed. 
         [0067]      FIG. 4  is a schematic of such an emergency call system  60  which includes an emergency call unit  62  having a speakerphone  64  (e.g., of the type disclosed in U.S. patent application Ser. No. 11/356,519, two remote speakerphone units  66 A with speakerphones  68 , an extension telephone  66 B and an over-ride accessory  70  interposed between the extension telephone  66 B and the jack. 
         [0068]    Various operative situations arise for the use of such an emergency call system  60 . First, consider a situation in which a handset of extension telephone  66 B is off-hook. Emergency call unit  62  cannot make any calls to the stored telephone numbers since it cannot get control of the telephone line. The extension telephone handset that is off-hook has locked out the emergency dialer. (It is of course possible to send a command signal to the over-ride accessory  70  to disconnect the extension telephone  66 B from the line.) In the following discussion, the speakerphone unit  66 A could be a standard telephone or speakerphone equipped with an over-ride accessory. For clarity, we shall refer to any unit capable of accessing a telephone line as a remote speakerphone unit. 
         [0069]    Second, consider a situation in which all remote speakerphone units  66 A are remote speakerphones, each equipped or associated with a pendant  78  for example, in the manner described above with respect to  FIG. 2 , and the main emergency call unit  62  is equipped with a means of communicating with the remote speakerphone units, typically with an RF transmitter (the transmit portion or component  74  being resident in the emergency call unit  62  and the receiver portion or component  76  being resident in the remote speakerphone). A remote speakerphone that is off-hook will also prevent calls from being made. If an emergency call unit  62  is equipped with a means of sending a signal to the remote speakerphones, it could command them to hang-up and thereby allow the emergency call unit  62  to place an emergency call. 
         [0070]    The person in distress depresses a button  80  on the emergency pendant  78  requesting help. The emergency call unit  62  checks the telephone line to determine if any remote speakerphone unit  66 A, e.g., handset  72 , is off-hook. If no remote speakerphone is off-hook, the emergency call unit  62  goes off-hook, seizes the telephone line, and proceeds to dial the first predetermined telephone number. 
         [0071]    On the other hand, if the emergency call unit  62  determines that one or more speakerphone units  66 A is off-hook, it will send a signal to each unit to hang-up. This clears the line and permits the emergency call unit  62  to go off-hook, seize the telephone line and commence the dialing operation. 
         [0072]    Once the main emergency call unit  62  has successfully taken control of the telephone line, it can send a signal to the other remote speakerphone units  66 A to go off-hook in the speakerphone mode. At this point, the main emergency call unit  62  and remote speakerphone units  66 A can broadcast the audio tones through the speakers indicating that the telephone number is being dialed. Once connected to the called party, all speakerphone units are able to communicate with the called party. 
         [0073]    Note that while the telephone number is being dialed by the emergency call unit  62 , the keypad on the remote speakerphone units  66 A can be disabled. This prevents the inadvertent pressing of a key on the keypad from interfering with the dialing process initiated by the emergency call unit  62 . Alternatively, the keypad on a remote speakerphone unit  66 A can be disabled during the entire emergency process to further prevent any incorrect signaling or interference. 
         [0074]    When the call is completed, and the main emergency call unit  62  hangs up, it will send a command to the remote speakerphone units  66 A to also hang up. The telephone line is now cleared again. The main emergency call unit  62  can now go off-hook, seize the telephone line, command the remote speakerphone units  66 A to go off-hook, and dial the next telephone number. 
         [0075]    Thus with such a system, a user requesting help will be able to request assistance by depressing a button  80  on a remote pendant  78 , and will be able to communicate with a called party from the area where the main emergency call unit  62  is located and all other areas equipped with a remote speakerphone unit  66 A. All remote speakerphone units  66 A and over-ride accessories  70  must be configured to respond to the transmission from the main emergency call unit  62 . 
         [0076]    The main emergency call unit  62  is in complete control of all operations during the calling sequences. At no time is it possible for the telephone line to be tied up preventing an emergency call from being placed. During normal situations, the main emergency call unit  62  and remote speakerphone units  66 A can be used as standard speakerphones with optional remote speakerphone activation. 
         [0077]    Referring now to  FIG. 5 , for those users requesting only emergency pendant use, an emergency call system can be provided which includes a single button pendant  82  that transmits an emergency request to a main emergency speakerphone unit  84  which will exercise control over any and all the remote speakerphone units  86  and over-ride accessories  88  associated with extension telephones  90 . This transmission is via a communications arrangement having a transmitter portion  92  resident in the main emergency speakerphone unit  84  and a receiver component  94 ,  96  resident in each of the remote speakerphone units  86  and over-ride accessories  88 . 
         [0078]    For those users requesting both emergency pendant use as well as remote speakerphone activation, a two-button pendant  98  can be provided (see  FIG. 6 ). One button  100  will be designated as the emergency request button (in accordance with the embodiment shown in  FIG. 5 ) and the second button  102  will be designated as the remote speakerphone activation button (in accordance with the embodiment shown in  FIG. 2 ). 
         [0079]    A variation of any of the embodiments of the invention described above is to provide a conventional cordless telephone which is tied into the speakerphone units or telephones. That is, a cordless telephone may be provided as the handset of any or all of the speakerphone units or telephones in the systems described above. This enables use of the systems at greater distances from the speakerphone units or telephones, e.g., outside of the home or office. 
         [0080]    Moreover, a repeater can be applied in any of the embodiments of the invention described above to increase the range of wireless communications. 
         [0081]    Another variation of the use of multiple speakerphone units in accordance with the invention for emergency dialing purposes is implemented when each speakerphone unit is designed to hold multiple telephone numbers to be called, for example, when a button on a pendant is pressed (in a manner described above). In such a situation, if there were four speakerphone units sixty feet apart and a person was thirty feet from the closest unit when he or she depresses a button on the speakerphone unit to initiate an emergency dialing routine, the first telephone number in the closest speakerphone unit would be dialed and the others speakerphone units would not dial any numbers. The speakerphone unit that is thirty feet from the user would be activated and the pendant would also be activated. Activation of the pendant would in turn activate the other speakerphone units and when the user comes in range of these subsequently activated speakerphone units, he or she can communicate using them. In this manner, communication can be seamless with the dialed party as the user moves in the home or office into and out of the range of multiple speakerphone units. Even if the user is a significant distance from one of the speakerphone units, he or she could still use the speakerphone units since it is activated via activation of the pendant. This is potentially useful since the range of the pendant is far in excess of the speakerphone range of a unit. 
         [0082]    Another variation of the invention involves providing communications between three locations using the speakerphone units. This may be accomplished by linking multiple telephone numbers in one or more of the speakerphone units. Thus, when a first speakerphone unit is activated, e.g., by depressing a button on a pendant, it would dial one number and connect to a similar, second speakerphone unit which in turn would be programmed to dial a third number. Dialing of the third number may be an automatic response or more preferably, only when receiving a call from the first speakerphone unit or a specific one of a pre-determined telephone numbers. To accomplish this, a processor in the speakerphone unit can be programmed to use the conventional “Caller ID” function to identify the source of an incoming call and compare the identified number to a list of numbers stored in its memory. If there is a match to one of the stored numbers, the speakerphone unit would dial another telephone number associated with the incoming number. In this manner, two or more connections are established between speakerphone units. Programming or design of the speakerphone units to achieve this function could be determined by one of ordinary skill in the art. 
         [0083]    Another embodiment of the invention enables a user of a cellular telephone, or other remote telecommunications device, to connect to the speakerphone units, i.e., into the speakerphone network. Using a cellular telephone, the user calls a telephone number assigned to the speakerphone unit and ties or links into the speakerphone unit. The speakerphone unit is activated, or multiple speakerphone units are activated, so that people in the home or office in which the speakerphone unit(s) is/are located can listen to whatever is being said or occurring in the vicinity of the cellular telephone and vice versa. Activation of the speakerphone unit may be either by a pendant as described above or can be by other means, such as by pressing a button on the speakerphone unit itself. Programming or design of the speakerphone units to achieve this function could be determined by one of ordinary skill in the art. 
         [0084]    In yet another embodiment of the invention shown schematically in  FIG. 7 , a master speakerphone unit  104  is designated and other speakerphone units  106  are considered slave units. The slave units  106  may be extension phones with speakerphone capabilities or other types of speakerphone units, such as described above. A pendant  108  having one or more buttons  110 , as described in any of the embodiments above, is associated with the master speakerphone unit  104  which may also include one or more buttons  112 . 
         [0085]    During emergency operation, when the user presses either button  110  or button  112 , the master speakerphone unit  104  is activated and dials the first telephone number stored in its memory. At the same time, it activates all of the slave speakerphone units  106 , i.e., activates their speakerphones. This can be achieved by the master speakerphone unit  104  sending a signal to the slave speakerphone units  106 , e.g., a wireless signal from a control module on the master speakerphone unit  104  to a reception and control module on the slave speakerphone unit  106 . The construction of such modules to provide for signal transmission and reception is readily ascertainable to one of ordinary skill in the art. 
         [0086]    Upon activation of the slave speakerphone units  106  by the master speakerphone unit  104 , once the called party connects to the telephone line, there will be an open telephone line between the master speakerphone unit  104  and the called party, with all of the slave speakerphone units  106  also being connected to the telephone line. In this manner, the user can talk and so long as they are within range of at least one of the master or slave speakerphone units  104 ,  106 , they can communicate with the called party. This is particularly useful is the user is immobile and cannot reach any of the master or slave speakerphone units  104 ,  106  but is within range of one of them. Additionally, this system is also applicable for non-emergency uses in that the user can roam around their home or office once the master speakerphone unit  104  activates the slave speakerphone units  106  and converse with the called party so long as they are within range of any one of the master or slave speakerphone units  104 ,  106 . 
         [0087]    An important aspect of this configuration of an emergency call system is that when the first telephone call is finished, the master speakerphone unit  104  is programmed to disconnect from the (first) called party and send a signal to disconnect all of the slave speakerphone units  106  from the telephone line. Then, the master speakerphone unit  104  is programmed to call a second telephone number stored in its memory and continue the process of calling the numbers in its memory and sequentially connecting and disconnecting the slave speakerphone units from the telephone line at the start and end of each call, respectively. 
         [0088]    To differentiate between the connection of the slave speakerphone unit  106  to the telephone and disconnection, master speakerphone unit  104  is preferably arranged to send different signals. One signal is a connect or activation signal (sent when the master speakerphone unit  104  is dialing a number) and the other is a disconnect or deactivation signal (sent when the master speakerphone unit  106  has terminated the call). 
         [0089]    It is also possible to construct the master speakerphone unit  104  to control the slave speakerphone units  106  based on the depression of one or more buttons on the pendant. For example, if the pendant includes two buttons, one button could be depressed to cause the master speakerphone unit  104  to activate all of the slave speakerphone units  106  and the other button could be depressed to cause the master speakerphone unit  104  to deactivate all of the slave speakerphone units  106 . A single button could be used with the sequential pressing of the button causing either activation or deactivation of the slave speakerphone units  106  by the master speakerphone unit  104 , but two buttons are preferred over one. 
         [0090]    Another variation of the invention entails programming multiple emergency call units in accordance with the invention with the same list of telephone numbers to call in an emergency situation. A pendant is provided with one or more buttons, and the speakerphone units include reception modules all designed to receive the same signal from the pendant when a button thereon is depressed. All the speakerphone units are connected to the same telephone line. With this set-up, so long as the user depresses the button within range of any of the speakerphone units, telephone calls will be made in the sequence of numbers stored in the memory of the speakerphone units. This set-up therefore increases the range of the system. The speakerphone units are programmed so that if more than one receives the signal from the pendant, only one initiates the calling sequence. 
         [0091]    Additional variations of the invention involve use of cellular telephones. Indeed, whenever mention is made of use of a speakerphone unit, any telecommunications unit which includes a microphone and a speaker is encompassed thereby. A cellular telephone or a satellite communication unit typically include a microphone and speaker and therefore can be used as speakerphone units in any of the embodiments of the invention described above. 
         [0092]    Having described a specific preferred embodiment of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to that precise embodiment, and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope or spirit of the invention as defined by the appended claims.