MXPA00005720A - System and method of responding to an incoming call while conferencing - Google Patents

Abstract

A method and apparatus for responding to an incoming call on one of a plurality of external telephone lines when a conference call is in progress on that external telephone line includes the following. First, caller identification information is received relating to the incoming call. Then the plurality of handsets involved in the conference call are notified that an incoming call has been received. Should it be desired to answer that incoming telephone call via a callback, a pre-recorded message is transmitted to the caller of the incoming call requesting the caller hang up and the incoming telephone call is terminated. The caller of the incoming call is then called back on a unused external telephone line using the previously received caller identification information relating to that incoming call. Finally, one of the plurality of handsets involved in the conference call is connected to the caller of the incoming call.

Description

SYSTEM AND METHOD TO RESPOND TO A LLANA THAT ENTERS WHILE IT IS IN CONFERENCE DESCRIPTION OF THE INVENTION The present invention relates to a multi-line subscriber telephone system, and to a method for operating said system, which implements an incoming call waiting feature for a call that enters an external telephone line, which is in use in a conference call without requiring that the conference call be suspended while the incoming call is answered. Figure 1 is a block diagram of a telephone subscriber system. In Figure 1, a plurality of bidirectional external telephone lines 5 is coupled to corresponding terminals of a telephone system called client premises equipment (CPE) 30. The CPE 30 is also bidirectionally coupled to a plurality of headphones 20. The headphones 20 they can be coupled to the CPE 30 through standard telephone cables, or through wireless radio transceivers in the CPE 30 and headphones 20, or through a combination of cable and wireless links. For example, current multi-line business telephone systems can link up to four external telephone lines and up to twelve corresponding telephone headsets. These headphones can be, for example, wireless headphones that operate over a radio frequency (RF) link in the unlicensed 900 MHz frequency band. In general, when a user wishes to place an outgoing call, he takes one of the headphones 20. The CPE 30 sends this and connects that handset to an unused one of the external telephone lines. 5. The user hears a dial tone and makes the outgoing call in the usual way. When an incoming call arrives on one of the external telephone lines 5, the CPE 30 assigns one of the headphones 20 to that telephone line. There are many known techniques for assigning the incoming telephone call to a handset. For example, the assignment may be a permanent assignment where each handset 20 is assigned to a corresponding line of the external telephone lines 5, or the CPE 30 can simply direct the incoming call to any unused handset 20, or all calls which enter initially may be directed to an individual handset 20 (e.g., a receptionist), or all of the headphones 20 may sound in response to all incoming calls. Any technique can be used to assign the incoming call to one or more headphones. The headset 20 assigned to receive the incoming telephone call sounds, the user takes the headset 20 and answers the incoming call in the usual way. There are several known features that can be provided by a telephone system 10 as illustrated in Figure 1. For example, system 10 can provide internal users of the system with an intercommunication feature. This feature can be implemented by allowing an internal user to call another directly through CPE 30 without using any of the external telephone lines 5. This feature can also allow several internal users to form an internal conference call between themselves, also through of the CPE 30 without using an external telephone line 5, all in a known way. Another example is the ability to form a conference call by allowing more than one of the headphones 20 to be connected to an individual external telephone line 5, thus allowing more than one local user to speak to the party at the other end of the telephone line. external 5. This feature can be implemented by allowing a user to place a call that goes over one of the external telephone lines 5 in the manner described above, and then allowing the user to an other internal users to that telephone call by connecting their headsets 20 in common to the external telephone line 5 connected to the external part, all in a known way. A known aspect, which is provided by the telephone transmission system to which external telephone lines 5 are coupled, is the "call waiting". This aspect provides an alert signal to a subscriber's handset, which is actually docked in a telephone call when an incoming call is trying to connect to that subscriber's handset. In response to the alert signal, the handset provides an indication of an incoming telephone call to the subscriber, in the form of a buzzing sound. In response to this indication, that subscriber can temporarily suspend the current telephone call (that is, place it on "hold") and answer the incoming telephone call. When the recently received telephone call is completed, the subscriber can reconnect to the original telephone call. In a normal consumer arrangement, where a standard telephone is attached to the external telephone line, no special circuit system or equipment is necessary to implement this aspect, since this aspect is provided by the central office. In a multi-line subscriber telephone system wherein a plurality of headsets 20 are connected to a plurality of external telephone lines 5, the CPE 30 need not provide any service for this aspect other than connecting a headset 20 to a telephone line. external 5. However, since the multi-line telephone system may also provide other functions along with the "call waiting" aspect and / or improvements to the "call waiting" aspect, the CPE 30 in such a system may include a circuit system to interact with the central office and provide the "call-waiting" aspect. Another known aspect that is provided by the telephone transmission system is the "caller ID (ID)". This feature is implemented by the central office. The "caller ID" inserts information regarding a telephone call that enters a subscriber when the subscriber's handset receives the indication of an incoming call. The information regarding the incoming telephone call includes the telephone number from which that call is made. That information can be displayed on the called handset 20, and used to determine who is calling and what action to take. This information can also be provided to a computer system, which can search previously stored data in relation to the calling telephone number and display that data to the called party. There are two modes of "caller ID". In I mode of the "caller ID", the phone being called is available to receive incoming (ie hung) telephone calls. The information regarding the incoming telephone call is transmitted from the central office to the headset that is being called as a part of the sound signal between the first and second sounds. There must be a device on the site of the headset that is called to be able to extract this information and either deploy it or supply it to a computer system, as described above. The user of the called handset can consult the information presented, or of the computer system, and decide whether to accept the incoming call and take the handset, or not. Mode II of the "caller ID" can be used together with the "call waiting" feature, described above. In mode II of the "caller ID", the called telephone can be paired in a telephone call (ie off-hook). The information regarding the incoming call, including the called telephone number, is sent together with the alert signal indicating that an incoming call is trying to connect to the currently occupied handset. As with mode I of the "caller ID", there must be an apparatus that can extract this information, and either deploy it or supply it to a computer system. The subscriber receives the "call waiting" buzz, as described above and can view the information regarding the incoming telephone call. Based on that information, the subscriber can decide whether or not to suspend the present telephone call and accept the new incoming call. A combination of the above known aspects is the conference call and "call waiting". European Patent Application No. EP 0 805 582, published on November 5, 1997, describes the principle of establishing a conference call in a subscriber telephone system, for example. The patent of E.U.A. 6,009,158, issued December 28, 1999, describes the caller's identification and related telephone services and functions. The patent of E.U.A. No. 5,857,017, issued January 5, 1999 and the patent of E.U.A. No. 5,894,504, issued April 13, 1999, describe call waiting and related telephone services and functions. Referring again to Figure 1, more than one local handset 20 may simultaneously be calling an external party through one of the external telephone lines 5, when an incoming call arrives for that external telephone line. In currently known systems, when the CPE (CAS) alert signal arrives from the central office, one, several, or all local headphones 20 produce a buzz indicating that a call is waiting. In response, one of the headphones can take control and place the actual conference call on hold to answer the incoming call. The control headset is connected, on the external telephone line, to the calling party of the incoming call. However, this places the entire conference call on hold. None of the local headphones can talk to the original external conference party. Only when the local control handset 20 completes the telephone call to the newly arrived incoming call is the external part that is reconnected to the local headset 20 and the conference call is re-established. It is desirable that the local headset users 20 involved in a conference call be notified of the newly arrived incoming call. However, it is also desirable that the user of one of the local headset control headphones 20 be able to answer the incoming call without unduly disrupting the conference call. In accordance with the principles of the present invention, a method for responding to an incoming call on one of a plurality of external telephone lines when a conference call is in progress on that external telephone line includes the following steps. First, the ID information of the mode II caller is received in relation to the incoming call. Then, the plurality of headphones involved in the conference call are notified that an incoming call has been received. If you wish to answer that incoming telephone call, a pre-recorded message is transmitted to the caller of the incoming call requesting that the caller hang up. The caller on the incoming call is then called on an unused external telephone line using the caller ID information previously received in connection with that incoming call. Finally, one of the plurality of headphones involved in the conference call is connected to the calling party of the incoming call. According to another aspect of the present invention, a telephone subscriber system includes a source of a plurality of external telephone lines, a plurality of headphones and a base unit, which is coupled between the external telephone line source and the headphones. There is a conference call circuit system in the base unit, which establishes a conference call involving the headphones and one of the external lines. The caller's identification circuit system, which is coupled to the external telephone lines, receives caller ID information related to an incoming telephone call on the conference call line. The call waiting circuit system sends a notification to the headset that an incoming call has been received, and receives instructions from a control headset to answer the incoming call via automatic call forwarding. A voice message circuit system transmits a pre-recorded message to the calling party of the incoming call requesting that the caller hang up. The automatic call diversion circuit system places an automatic call forwarding of the incoming call on an unused line using the caller's identification information, and connects the control headset to the automatic diverting line of the call. call. A multi-line subscriber telephone system in accordance with the present invention provides the call waiting function for an external telephone line carrying a conference call without requiring that the conference call be unduly interrupted, and without requiring any change in the head office. In the drawings: Figure 1 is a block diagram of a known subscriber telephone system; Figure 2 is a more detailed block diagram of customer premises equipment according to the principles of the present invention; Figure 3 is a waveform diagram illustrating time control of signals transmitted from the central office to the customer's premises equipment, and is useful in understanding the operation of the present invention; and Figures 4 and 5 are flowcharts also useful for understanding the operation of the present invention. Figure 2 is a more detailed block diagram of the customer premises equipment 30 (or base unit) in accordance with the principles of the present invention. In Figure 2, the base unit is coupled to headphones 20 (of Figure 1) via an RF link, preferably in the 900 MHz band. One skilled in the art will understand that headphones 20 can be coupled to the base unit through any suitable means. In the embodiment illustrated in Figure 2, four bidirectional external telephone lines 5 are coupled to corresponding terminals of four corresponding POTS interface circuits (old plan telephone service) 32, (POTS 1, POTS 2, POTS 3, POTS 4, respectively), and to respective input terminals of a sound input signal recognition circuit 34. Each of the respective POTS interface circuits has an output terminal and an input terminal coupled to corresponding terminals of a processor circuit. of digital signal and telephony interface 36 (DSP / TI). The sound input signal recognition system 34 has a four-line output terminal coupled to a corresponding input terminal of the DSP / TI circuit 36. The DSP / TI circuit 36 has a bidirectional output terminal coupled to a corresponding terminal of the RF circuit system 38. The RF circuit system 38 is coupled to an RF antenna 35. The DSP / TI circuit 36 includes a microprocessor 40. The microprocessor 40 is coupled to a code memory 42 and an audio message memory 44 through a system bus 45. Although illustrated as separate memory, one skilled in the art will understand that these memories may be different portions of a single memory circuit. Further, although it is illustrated as external to I DSP / TI 36, one skilled in the art will understand that the DSP / TI 36 may internally include all, or a portion of the audio message memory 44 and the code memory 42. The DSP / TI circuit is also coupled to an ID processing circuit of the caller 39 through a bidirectional signal line. During operation, the POTS interface circuits 32 operate in a known manner to receive signals from and transmit signals to the external telephone network, including both audio signals, as well as the various other non-voice signals transmitted over the external telephone lines . The sound input signal recognition circuit 34 especially recognizes the sound signals received from the external telephone lines, and provides indications of the presence of sound signals on the respective external telephone lines to the DSP / TI circuit 36 also in a form known Similarly, the RF circuit system 38 operates to transmit audio signals to and receive audio signals from the headphones 20 (of Figure 1). In the illustrated embodiment, the RF circuit system employs a combination of time division multiplexer and frequency band selection to overcome source interference and to maintain reliable links between the base unit 30 and the remote headset 20 in a form known In the illustrated embodiment, four headphones 20 are present. However, the known RF circuit system can support 12 or more 20 headphones. The DSP / TI circuit 36 operates as a 4 x 12 telephone switch to connect the four external telephone lines 5 to up to 12 headphones 20. The microprocessor 40 reads the instructions from the code memory 42 and reads the data from and writes data to the code memory 42. Accordingly, the code memory 42 may include non-volatile read-only memory (ROM) containing the program code for the microprocessor 40, and read / write memory (RAM) for the data. In addition, the microprocessor 40 includes an input / output circuit system (not shown) for receiving status signals from and transmitting control signals to the various interface circuits, and internal registers (not shown) in order to control the operation of the telephone system 10, all in a known manner. For example, the microprocessor 40 can control the telephone system 10 in a known manner, to allow a conference call to be established. To do this, a telephone call is first established between a remote party through one of the external telephone lines 5 and several of the headphones 20 (of Figure 1) through the RF circuit system 38 and the antenna 35. A Once established, the microprocessor 40 continues to verify that external telephone line for several warning signals, that the external telephone network (to which the external telephone lines are connected) sends to the base unit 30. This signal is the warning signal of client "call waiting" of mode II. Figure 3 is a waveform diagram illustrating the time control of a "call waiting" and "caller ID" sequence of signals transmitted between the central office and the customer premises team, and figures 4 and 5 are flow charts, all useful for understanding the operation of the present invention in response to this signal sequence. Referring to Figure 3, the horizontal axis represents time, and the illustrated signals, represented by rectangles, are non-voice signals inserted into the external telephone line currently in use for a conference call, as described above. In the leftmost portion of the waveform, a standard voice conversation is being presented. At or just from time 50, an incoming call is received for the external telephone line. A CPE alert signal (CAS), of known format and having a duration of 75 to 85 milliseconds (ms) is transmitted from the central office to the base unit 30 to alert the base unit of the incoming call, it is say, the CAS is a "call-waiting" signal. This signal requires a recognition signal (ACK), also sent from the base unit to the central office in 100 ms of the term of the CAS signal. At time 52, the base unit begins the transmission of the recognition signal, ACK, of known format and having a duration of 60 + 5 ms towards the central office. At time 54, in 500 ms after receiving an acknowledgment signal (ACK), the central office transmits a data reinforcement, in a known frequency shift key format, to the base unit. The data reinforcement can include one or more messages. Specifically, this data reinforcement contains caller ID information (CID) related to the incoming call. The duration of this data reinforcement depends on the amount of data in the messages. The CID information contained within the data reinforcement can be extracted, and the data related to the incoming telephone call can be displayed to the user, as described above. In order for the signals to be successfully transmitted between the central office and the base unit, the telephone conversation on the external telephone line is muted during the signal sequence illustrated in Figure 3. From the end of the CAS signal at the time 51 to no more than 50 ms after the end of the data reinforcement in time 55, the conversation is muted. The length of time in which the conversation remains muted is about 1 second, which is not unduly intrusive.

Figure 4 illustrates the operation of the base unit, while verifying the external telephone line to detect the CAS signal. In the illustrated embodiment, wherein the operation of the base unit is controlled by the microprocessor 40, the flow diagram of Figure 4 represents the operation of a portion of the program executed by the microprocessor 40. In block 102, the microprocessor 40 in the base unit 30 begins to verify the external telephone line 5 on which the conference call is being presented. In block 104, the CAS signal is recognized. In block 106, the conference call is muted and the acknowledgment signal is transmitted to the central office. In block 108, the data reinforcement containing the CID information is received. The CID information is extracted and stored in the code memory 42 for later retrieval. In block 110, the conference call is not muted. In block 112, an indication that an incoming call is on hold, which may be in the form of a buzz, is sent from the base unit 30 to all the headsets 20 involved in the conference call, together with the caller ID information related to the incoming call. The base unit 30 then begins to wait for a response from the headset 20. If so, then a portion 200 of the microprocessor program 40 is executed to answer the incoming call. Otherwise, in block 116, the chronometer is decreased. In block 118, if the timer has reached zero, then it is assumed that no handset 20 is handling the incoming call, and the verification program is terminated in block 120. On the other hand, if the chronometer has not reached zero, then the headphones 20 are checked again to determine if one or more has answered the incoming call. Referring to Figure 5, the program portion 200 of the microprocessor 40 for handling the input call is illustrated and entered into the block 202. In block 204, it is determined whether more than one of the headphones 20 has responded to the Incoming call. If more than one handset 20 has answered the incoming call, then the response control is selected. This can be done through any of the known methods for selecting one of a plurality of competition resources, such as the one that first enters first is served, or line of exit, or a priority scheme. In block 206, the microprocessor 40 determines whether the control handset 20 indicated that the incoming telephone call was not handled using the automatic call diversion scheme, described in more detail below. If an automatic call diversion was indicated by the control handset 20 in block 206, then in block 208 a check is made to determine if one of the external telephone lines 5 is free. If any control handset 20 does not request an automatic call diversion, or no external telephone line 5 is available, then the incoming call is handled in the normal "call waiting" manner. That is, the current conference call is suspended in block 224. This means that the external conference call part is temporarily disconnected from the base unit 30 (i.e., it is placed as hung), and the control handset 20 is coupled to receive the incoming call. In block 220, microprocessor 40 waits until the incoming call is completed. Only at that time, in block 222, the external conference call part is reconnected to the base unit 30 and the control handset 20 is reconnected to the conference call, all in a known manner. However, if an automatic call diversion is requested by the control handset 20, and an external telephone line is available 5, then an automatic call forwarding sequence is initiated. In block 210, the current conference call is suspended, i.e., the external conference call part is placed as off-hook. In block 212, the microprocessor 40 retrieves the dice representing a pre-recorded vos message from the audio message memory 44 and transmits the voice message to the calling party of the incoming call. This message instructs the calling party to hang up the phone, and it will be automatically diverted immediately. The base unit then ends the incoming telephone call. In block 214, the current conference call is resumed on the current external telephone line 5, with the exception of the control handset 20. In block 216, a call is placed over the free external telephone line for the number of the call input, as indicated by the previously stored CID information (block 108 of Figure 4). When this automatic call forwarding is placed, the control headset 20 is connected to that external telephone line of block 218. The microprocessor 40 then waits for that call to be completed in block 220. When the call being made is completed , then the control handset 20 is reconnected to the conference call in block 222. By allowing a local headset the opinion of handling an incoming call on a line already involved in a conference call by a bypass mechanism automatic call as described above, a complete conference call does not need to be interrupted while the incoming call is answered. Rather, the call just needs to be interrupted long enough to send a voice message to the caller to hang up. Afterwards, only one of the local headphones needs to leave the conference call to answer the incoming call. This is especially advantageous in a business establishment where conference calls are probably very important, and less manageable to be interrupted.

Claims (14)

1. - A method for responding to an incoming call on one of a plurality of external telephone lines (5) to which a subscriber telephone system (10), comprising a plurality of headphones (20), is coupled, when a call from conference is in progress on one of the external telephone lines, the method comprises the steps of: receiving (108) identifying information of the caller in relation to the incoming call; notifying (112) the plurality of headphones involved in the conference call that an incoming call has been received, the method characterized by the additional steps of: receiving instructions (114) from one of a plurality of control headphones to respond ( 200) to the incoming call through the automatic call forwarding; transmitting (212) a pre-recorded message to the caller of the incoming call requesting that the caller hang up; placing an automatic call diversion (216) in the calling of the incoming call into one of a plurality of unused external telephone lines using the caller's identification information in relation to the incoming call; and connecting (218) one of the plurality of control headphones involved in the conference call to the external telephone line for automatic call diversion.

2. - The method according to claim 1, further comprising the step of reconnecting one of the plurality of control headphones to the conference call when the automatic call forwarding is completed.

3. The method according to claim 1, wherein the step of receiving identification information from the caller comprises the steps of: verifying one of the plurality of external telephone lines for non-voice signals from a central office coupled to the plurality of external telephone lines; detect a customer premises equipment alert signal; mute the conference call; send an acknowledgment signal to the central office; receive the data reinforcement containing the identification information of the caller; Do not mute the conference call; and store the caller's identification.

4. The method according to claim 1, wherein the step of transmitting the pre-recorded message comprises the steps of: suspending the conference call; transmit the pre-recorded message to the caller of the incoming call; end the incoming phone call; and resume the conference call.

5. The method according to claim 1, wherein the step of receiving instructions comprises the steps of: determining whether more than one of the plurality of headphones responds to the notification; if more than one of the plurality of headphones has responded to the notification, select one of more than one of the plurality of headphones as the control handset; and receive instructions from the control headset.

6. The method according to claim 1, wherein the telephone subscriber system further comprises a base unit, further comprising the step of connecting the plurality of headphones to the base unit through a radio frequency link of 900. MHz.

7. A base unit (30) of a telephone subscriber system (10) having a source of a plurality of external telephone lines (5) and a plurality of headphones (5), wherein the base unit is coupled between the external telephone line source and the plurality of headphones, the base unit comprising: headphones and one of the plurality of external lines (5); a calling circuit identification system (39), coupled to one of the external telephone lines, to receive (108) caller identification information in relation to an incoming telephone call; a call waiting circuit system for notifying (112) the plurality of headsets that an incoming call has been received, wherein the call waiting circuit system is for receiving (114) instructions from a control headset. the plurality of headphones to respond (200) to the incoming call by automatic call forwarding; a voice message circuit system (40, 44) for transmitting (212) a pre-recorded message to the caller of the incoming call requesting that the caller hang; and an automatic call diversion circuit system for placing an automatic call diversion (216) to the caller of the incoming call on an unused line of the plurality of external telephone lines using caller ID information to the incoming call and to connect (218) a headset to control the plurality of headsets to the internal telephone line for automatic call diversion.

8. The system according to claim 7, wherein the caller's identification circuit comprises: a circuit system for verifying one of the plurality of external telephone lines for non-voice signals from a central office coupled to the plurality of external telephone lines; a circuit system for detecting a customer premises equipment alert signal; a circuit system to mute the conference call; a circuit system for sending a recognition signal to the central office; a circuit system for receiving a data reinforcement containing the identification information of the caller; a memory to store the identification information of the caller; and a circuit system to not mute the conference call.

9. The system according to claim 8, wherein the automatic call diversion circuit system comprises a circuit system for recovering the caller's identification information from the memory.

10. The system according to claim 7, wherein the call waiting circuit comprises: a circuit system for determining if more than one of the plurality of headphones responds to the notification; a circuit system for selecting one of more than one of the plurality of headphones as the control handset if more than one of the plurality of headphones has responded to the notification; a circuit system to receive instructions from the control headset.

11. The system according to claim 7, wherein the voice message circuit system comprises: a memory for storing data representing the pre-recorded message circuit system for suspending the conference call; a circuit system for recovering data representative of the memory message; a circuit system for converting representative message data to an audio message signal; a circuit system for transmitting the audio message signal to the caller of the incoming call; a circuit system to terminate the incoming telephone call; and a circuit system to resume the conference call.

12. The system according to claim 7, wherein the automatic call diversion circuit system further comprises a circuit system for reconnecting the control headset of one of the plurality of headsets to the conference call when automatic call forwarding is completed.

13. The system according to claim 7, wherein the conference call circuit system, the call waiting circuit system, the voice message circuit system and the automatic call diversion circuit system are included in a microprocessor.

14. The system according to claim 7, wherein the base unit and each of the plurality of headphones comprise 900 MHz radio frequency transceivers to connect the headphones to the base unit.