Abstract:
With a conventional hands-free system formed by a radio apparatus and a hands-free apparatus connectable to each other by a local radio link, accepting a call on the hands-free apparatus is ineffective after the radio apparatus starts to send a reply message. There is provided a method for hands-free control to solve this problem. The method comprises measuring time since transferring a call arrived at the radio apparatus to the hands-free apparatus, and establishing a voice channel on the local radio link in a case where an operation is done to accept the call on the hands-free apparatus while the reply message is being sent.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2004-113012 filed on Apr. 7, 2004; the entire contents of which are incorporated herein by reference.  
       FIELD OF THE INVENTION  
       [0002]     The present invention relates to a method for controlling a hands-free system, a radio apparatus, and a hands-free apparatus.  
       DESCRIPTION OF THE BACKGROUND  
       [0003]     Radio communications are now widely used, including on moving vehicles or in any busy situations. Hands-free systems are used for such kinds of radio communications to assure traffic safety or any kind of conveniences. A hands-free system is formed by a radio apparatus, e.g., a cellular phone, and a hands-free apparatus.  
         [0004]     A radio apparatus and a hands-free apparatus are linked to each other by a local radio link to form a hands-free system, provided that they are capable of sending and receiving radio signals through the link. Examples of such a local radio link are Bluetooth (TM) and a wireless local area network (WLAN), and particularly in the Bluetooth specifications there is provided a standardized hands-free profile to support such kinds of applications.  
         [0005]     Here is assumed a hands-free system formed by a radio apparatus and a hands-free apparatus. The hands-free apparatus has a microphone, a loud speaker, and an operation panel. The hands-free apparatus is connectable to the radio apparatus by a local radio link, and the radio apparatus may be set normal, i.e., to be used while being held by a human hand, or hands-free. When the radio apparatus is set hands-free, a control channel is established on the local radio link.  
         [0006]     The radio apparatus is used as an ending node of a communication network. An incoming phone call received at the radio apparatus is transferred to the hands-free apparatus through the control channel. The call may be accepted on the hands-free apparatus, i.e., by operating the operation panel thereof. When the call is accepted on the hands-free apparatus, a voice channel is established on the local radio link to enable a voice communication in a hands-free manner, using the microphone and the loud speaker of the hands-free apparatus.  
         [0007]     When a call arrives at the radio apparatus from another ending node of the communication network, i.e., the other party on the phone, the call is transferred from the radio apparatus to the hands-free apparatus through the control channel. If the call is not accepted on the hands-free apparatus during a predetermined time period, the radio apparatus reads out a reply message, like “Sorry, I am not available for the time being”, stored in a built-in memory and sends the reply message to the other party, as one of usual functions of radio apparatuses.  
         [0008]     Accepting the call on the hands-free apparatus is usually ineffective after sending the reply message begins. That is inconvenient, in a case where an operation to accept the call has to be delayed due to an instantaneous traffic situation or some other reasons although such an operation has been intended.  
         [0009]     Vehicular phone systems were improved to alleviate a danger when a call arrives at a radio apparatus included in the system, and the improved systems are disclosed in the Japanese published patent applications, e.g., H11-4190 and 2003-51895, the English versions of which are available on the Japan Patent Office website.  
         [0010]     The former one of those conventional systems determines if the vehicle is moving or not, when a call from another party arrives at the radio apparatus, based on the velocity data obtained by a velocity measurement unit on board. When it is determined that the vehicle is moving, a reply message is sent back, saying that the call cannot be accepted since the vehicle is moving, and a spoken message of the other party is recorded, if any.  
         [0011]     The latter one sends a reply message to the other party including vehicular status in addition to the information if it is moving or not at the time when the call arrives at the radio apparatus. That may help not to receive repetitive calls from the other party, who understands the vehicular status well due to the contents of the reply message.  
         [0012]     These conventional techniques, however, do not solve the problem that accepting the call on the hands-free apparatus is ineffective after sending a reply message begins.  
       SUMMARY OF THE INVENTION  
       [0013]     To solve the technical problem described above, an advantage of the present invention is to provide a method for controlling a hands-free system that enables accepting a call by operating the hands-free apparatus, even after sending a reply message begins.  
         [0014]     According to one aspect of the present invention to achieve the above advantage, there is provided a method for controlling a hands-free system formed by a radio apparatus and a hands-free apparatus connectable to each other by a local radio link. The radio apparatus is configured to be a first ending node of a communication network, and to have a memory. The hands-free apparatus is configured to enable an operation to accept a call thereon.  
         [0015]     The method for hands-free control comprises establishing a control channel on the local radio link, receiving a call at the radio apparatus, the call being sent by a second ending node of the communication network, sending the call from the radio apparatus to the hands-free apparatus through the control channel, measuring time on the radio apparatus after sending the call to the hands-free apparatus, starting to send a reply message read out of the memory to the second ending node, in a case where a period of the measured time reaches a predetermined time period while the call is not accept on the hands-free apparatus, establishing a voice channel on the local radio link in a case where the call is accepted on the hands-free apparatus before a period of the measured time reaches the predetermined time period, or in a case where the call is accepted on the hands-free apparatus while the reply message is being sent, and conducting a hands-free voice communication between the second ending node and the hands-free system, after establishing the voice channel.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a block diagram of a first embodiment of a hands-free system of the present invention.  
         [0017]      FIG. 2  is a block diagram of a main part of a radio apparatus of the first embodiment.  
         [0018]      FIG. 3  is a diagram of a processing sequence and signal flows of the first embodiment of a method for controlling a hands-free system of the present invention.  
         [0019]      FIG. 4  is a diagram of a processing sequence and signal flows of a second embodiment of a method for controlling a hands-free system of the present invention.  
         [0020]      FIG. 5  is a diagram of a processing sequence and signal flows of a third embodiment of a method for controlling a hands-free system of the present invention.  
         [0021]      FIG. 6  is a block diagram of a fourth embodiment of a hands-free apparatus of the present invention.  
         [0022]      FIG. 7  is a diagram of a processing sequence and signal flows of the fourth embodiment of a method for controlling a hands-free system of the present invention.  
         [0023]      FIG. 8  is a diagram of a processing sequence and signal flows of a fifth embodiment of a method for controlling a hands-free system of the present invention.  
         [0024]      FIG. 9  is a diagram of a processing sequence and signal flows of a sixth embodiment of a method for controlling a hands-free system of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     A first embodiment of the present invention will be described with reference to  FIG. 1  through  FIG. 3 .  FIG. 1  is a block diagram of a hands-free system of the first embodiment.  
         [0026]     The hands-free system  1  is formed by a radio apparatus  10  and a hands-free apparatus  20 . The radio apparatus  10  is used as a first ending node of a communication network  30 . A second ending node  40  is connected to the communication network  30 . An example of the second ending node  40  is, though not limited to, a cellular phone. The radio apparatus  10  and the hands-free apparatus  20  are connectable to each other by a local radio link, e.g., Bluetooth (TM) or WLAN. The radio apparatus  10  may be set either normal, i.e., to be used being held by a human hand, or hands-free.  
         [0027]     The hands-free apparatus  20  has, e.g., a panel on which an operation is performed to accept a call sent from other ending nodes including the second ending node  40 , and transferred from the radio apparatus  10  being set hands-free. The panel may be physically or virtually (e.g., on a screen) implemented. The hands-free apparatus  20  has, e.g., a microphone and a loud speaker to enable voice inputs and outputs in a hands-free manner.  
         [0028]      FIG. 2  is a block diagram of a main part of the radio apparatus  10  shown in  FIG. 1 . The radio apparatus  10  has a first antenna  11  used for sending and receiving radio signals to and from the communication network  30  (more precisely a radio station belonging thereto). Those radio signals carry data and voice conveyed by the communication network  30 .  
         [0029]     The first antenna  11  is connected to a first radio circuit  12  that performs transmission of radio signals including coding, modulation, amplification, and so on, and reception of radio signals including amplification, demodulation, decoding, and so on.  
         [0030]     The radio apparatus  10  has a second antenna  13  used for sending and receiving local radio signals to and from the hands-free apparatus  20 . Those local radio signals carry data through a control channel established on the local radio link, and carry voice through a voice channel established on the local radio link.  
         [0031]     The second antenna  13  is connected to a second radio circuit  14  that performs transmission of local radio signals including coding, modulation, amplification, and so on, and reception of local radio signals including amplification, demodulation, decoding, and so on.  
         [0032]     The radio apparatus  10  has a memory  15  on which stored is a reply message. The reply message is, e.g., “Sorry, I am not available for the time being, such and such”.  
         [0033]     The radio apparatus  10  has a control circuit  16  that is connected to the first radio circuit  12 , the second radio circuit  14 , and the memory  15  via a common bus  17 . The control circuit  16  is, e.g., a microprocessor unit or a digital signal processor, and performs a hands-free control of the first embodiment.  
         [0034]     A method for controlling the hands-free system  1  of the first embodiment will be described with reference to  FIG. 3 , which is a diagram of a processing sequence and signal flows among the second ending node  40 , the radio apparatus  10 , and the hands-free apparatus  20  of the first embodiment.  
         [0035]     The control circuit  16  exchanges data necessary to establish a control channel with the hands-free apparatus  20 , according to a specified protocol of the local radio link. Local radio signals carrying those data are sent to and received at the second radio circuit  14  and the second antenna  13 . As the result a control channel is established on the local radio link (Step “S 1 ”). The control circuit  16  sets the radio apparatus  10  hands-free and waits for a call arriving from any other ending node of the communication network  30 .  
         [0036]     The control circuit  16  receives a call sent by the second ending node  40  and conveyed by the communication network  30 , with the first antenna  11  and the first radio circuit  12  (Step “S 2 ”). The control circuit  16  sends the call to the hands-free apparatus  20  through the control channel, with the second radio circuit  14  and the second antenna  13  (Step “S 3 ”).  
         [0037]     The control circuit  16  measures time after sending the call to the hands-free apparatus  20  (Step “S 4 ”). The hands-free apparatus  20  requests the radio apparatus  10  to establish a voice channel on the local radio link, through the control channel, when the call is accepted on the hands-free apparatus  20 . The control circuit  16  is thereby aware if the call has been accepted on the hands-free apparatus  20  or not.  
         [0038]     When a period of the measured time reaches a predetermined time period while the call is not accepted on the hands-free apparatus  20  (“YES” of Step “S 5 ”), the control circuit  16  reads the reply message out of the memory  15 , and starts to send the reply message to the second ending node (Step “S 6 ”, or “ARM STARTING”, where “ARM” stands for an automatic reply message), with the first radio circuit  12  and the first antenna  11 .  
         [0039]     While the reply message is being sent (Step “S 7 ”), the call has been neither accepted nor rejected yet. When the call is accepted on the hands-free apparatus  20  in the meantime (“YES” of Step “S 8 ”), the control circuit  16  receives a request to establish a voice channel, and is aware that the call has been accepted on the hands-free apparatus  20 , as described above.  
         [0040]     The control circuit  16  exchanges data necessary to establish a voice channel with the hands-free apparatus  20 , according to a specified protocol of the local radio link. Local radio signals carrying those data are sent and received with the second radio circuit  14  and the second antenna  13 . As the result a voice channel is established (Step “S 9 ”).  
         [0041]     Once the voice channel is established on the local radio link, the control circuit  16  receives incoming voice messages from the second ending node  40  with the first antenna  11  and the first radio circuit  12 , and transfers to the hands-free apparatus  20  through the voice channel with the second radio circuit  14  and the second antenna  13 . The control circuit  16  receives outgoing voice messages from the hands-free apparatus and sends to the second ending node  40  vice versa. A hands-free voice communication is thus conducted between the second ending node  40  and the hands-free system  1  (Step “S 10 ”).  
         [0042]     When the call is accepted on the hands-free apparatus  20  before the measured time reaches the predetermined time period (“NO” of Step “S 5 ”), the hands-free apparatus  20  and the radio apparatus  10  establish the voice channel (Step “S 9 ”) as described above. This sequence goes through a circled “A” as illustrated in  FIG. 3 .  
         [0043]     When the call is not accepted on the hands-free apparatus  20  before sending the reply message ends (“NO” of Step “S 8 ”), the control circuit  16  rejects the call and goes back to the status of waiting for an arriving call before Step “S 2 ”. This sequence goes through a circled “B” as illustrated in  FIG. 3 .  
         [0044]     A spoken message sent from the second ending node  40  may be recorded and stored on the memory  15  before rejecting the call, in a case where the reply message includes inviting to leave a message.  
         [0045]     The radio apparatus  10  may be set normal before the call is accepted on the hands-free apparatus  20 . A normal voice communication is conducted while the radio apparatus  10  is being held by a human hand in such a case.  
         [0046]     According to the first embodiment described above, accepting a call on the hands-free apparatus is allowed not only before starting to send the reply message but also while it is being sent. This advantage makes hands-free systems more convenient and user-friendly than conventional ones.  
         [0047]     A second embodiment of the present invention will be described with reference to  FIG. 4 .  FIG. 1  and  FIG. 2  will also be referenced as a hands-free system of the second embodiment has the same configuration as the one of the first embodiment shown in  FIG. 1  and  FIG. 2 .  
         [0048]     The same reference numerals given to the apparatuses, components or units in these figures will be used in the following description, and a detailed explanation of them is omitted. A ringing sound is stored on the memory  15  in addition to the reply message described in the first embodiment.  
         [0049]      FIG. 4  is a diagram of a processing sequence and signal flows among the second ending node  40 , the radio apparatus  10 , and the hands-free apparatus  20  of the second embodiment.  
         [0050]     Establishing a control channel on the local radio link (Step “S 41 ”), receiving a call at the radio apparatus  10  (Step “S 42 ”), sending the call to the hands-free apparatus (Step “S 43 ”), and measuring time (Step “S 44 ”) are identical to Steps “S 1 ”, “S 2 ”, “S 3 ”, and “S 4 ”, respectively, in  FIG. 3 , and a detailed explanation of these steps is omitted.  
         [0051]     While measuring time (Step “S 44 ”), the control circuit  16  exchanges data necessary to establish a voice channel in advance according to a specified protocol, with the hands-free apparatus  20 , and establish the voice channel on the local radio link (Step “S 45 ”). The voice channel established in advance is identical to the voice channel in the first embodiment, and is used to transfer sounds as well as voice messages.  
         [0052]     The control circuit  16  reads the ringing sound out of the memory  15 , and sends the sound to the hands-free apparatus  20  through the voice channel, with the second radio circuit  14  and the second antenna  13  (Step “S 46 ”). The hands-free apparatus  20  rings by reproducing the sound, e.g., from the loud speaker.  
         [0053]     When a period of the measured time reaches a predetermined time period while the call is not accepted on the hands-free apparatus (“YES” of Step “S 47 ”), the control circuit  16  releases the voice channel with the hands-free apparatus  20  (Step “S 48 ”). Then the control circuit  16  reads the reply message out of the memory  15 , and starts to send the reply message to the second ending node  40  (Step “S 49 ”) as at Step “S 6 ” in  FIG. 3 .  
         [0054]     Sending the reply message (Step “S 50 ”), accepting the call on the hands-free apparatus  20  (Step “S 51 ”), establishing the voice channel (Step “S 52 ”), and conducting a hands-free voice communication (Step “S 53 ”) are identical to Steps “S 7 ”, “S 8 ”, “S 9 ”, and “S 10 ”, respectively, in  FIG. 3 , and a detailed explanation of these steps is omitted. It should be noted, though, that Step “S 52 ” is re-establishing the voice channel in the second embodiment.  
         [0055]     When the call is accepted on the hands-free apparatus  20  before the measured time reaches the predetermined time period (“NO” of Step “S 47 ”), the sequence goes through a circled “C” as illustrated in  FIG. 4 , and a detailed explanation of which will be described later as another embodiment of the present invention.  
         [0056]     When the call is not accepted before sending the reply message ends (“NO” of Step “S 51 ”), the control circuit  16  rejects the call and goes back to the status of waiting for an arriving call before Step “S 42 ”. This sequence goes through a circled “D” as illustrated in  FIG. 4 .  
         [0057]     According to the second embodiment described above, the hands free-apparatus informs of the call arrival by ringing. This advantage helps an earlier acknowledgement of a call arrival and enables a smoother hands-free voice communication.  
         [0058]     A third embodiment of the present invention will be described with reference to  FIG. 5 .  FIG. 1  and  FIG. 2  will also be referenced as a hands-free system of the third embodiment has the same configuration as the one of the first embodiment shown in  FIG. 1  and  FIG. 2 .  
         [0059]     The same reference numerals given to the apparatuses, components or units in these figures will be used in the following description, and a detailed explanation of them is omitted. A ringing sound is stored on the memory  15  as in the second embodiment.  
         [0060]      FIG. 5  is a diagram of a processing sequence and signal flows among the second ending node  40 , the radio apparatus  10 , and the hands-free apparatus  20  of the third embodiment. Steps “S 41 ” through “S 47 ” are the same as in  FIG. 4 , and that is why the same reference names are given to these steps, a detailed explanation of which is omitted.  
         [0061]     When the call is accepted on the hands-free apparatus  20  before the measured time reaches the predetermined time period (“NO” of Step “S 47 ”, and Step “S 47   a ”), the hands-free apparatus  20  and the radio apparatus  10  maintain the voice channel established at Step “S 45 ” and conduct the hands-free voice communication of Step “S 53 ” using the voice channel.  
         [0062]     When a period of the measured time reaches a predetermined time period while the call is not accepted on the hands-free apparatus (“YES” of Step “S 47 ”), the sequence follows Steps “S 48 ” through “S 52 ” in  FIG. 4 , as described in the second embodiment.  
         [0063]     According to the third embodiment described above, the voice channel is not released and is used to transfer voice messages between the radio apparatus and the hands-free apparatus, thus simplifying the sequence in a case where the call is accepted within the predetermined period.  
         [0064]     A fourth embodiment of the present invention will now be described with reference to  FIG. 6  and  FIG. 7 .  FIG. 1  will also be referenced since a hands-free system in the fourth embodiment has the same configuration as the one in the first embodiment shown in  FIG. 1 . The same reference numerals given to the apparatuses, components or circuits in these figures will be used in the following description, and a detailed explanation of these is omitted.  
         [0065]      FIG. 6  is a block diagram of a hands-free apparatus  20  of the fourth embodiment. The hands-free apparatus  20  has an antenna  21  used for sending and receiving local radio signals to and from the radio apparatus  10 . These local radio signals carry data through a control channel established on the local radio link, and carry voice through a voice channel established on the local radio link.  
         [0066]     The antenna  21  is connected to a radio circuit  22  that performs transmission of local radio signals including coding, modulation, amplification, and so on, and reception of local radio signals including amplification, demodulation, decoding, and so on.  
         [0067]     The hands-free apparatus  20  has an operation device  23  that is, e.g., a panel physically or virtually (e.g., on a screen) implemented, on which an operation is performed to accept a call from other ending nodes including the second ending node  40 . The hands-free apparatus  20  has, e.g., a microphone and a loud speaker (both are not shown) to enable voice inputs and outputs in a hands-free manner.  
         [0068]     The hands-free apparatus  20  has a hands-free control circuit  24  that is connected to the radio circuit  22  and the operation device  23  via a common bus  25 .  
         [0069]     The hands-free apparatus  20  sends and receives local radio signals to and from the radio apparatus  10  with the radio circuit  22  and the antenna  21 , and has the radio apparatus  10  send and receive radio signals to and from the communication network  30 , as controlled by the hands-free control circuit  24 . A sequence including such sending and receiving will be described later. The hands-free control circuit  24  is, e.g., a microprocessor or a digital signal processor, and performs a hands-free control of the fourth embodiment.  
         [0070]     A method for controlling the hands-free system  1  in the fourth embodiment will be described with reference to  FIG. 7 , which is a diagram of a processing sequence and signal flows among the second ending node  40 , the radio apparatus  10 , and the hands-free apparatus  20  in the fourth embodiment.  
         [0071]     The hands-free apparatus  20  exchanges data necessary to establish a control channel with the radio apparatus  10 , according to a specified protocol of the local radio link. Local radio signals carrying these data are sent and received with the radio circuit  22  and the antenna  21 . As the result a control channel is established on the local radio link (Step “S 71 ”). The radio apparatus  10  sets itself hands-free as described in the first embodiment.  
         [0072]     The radio apparatus  10  receives a call sent by the second ending node  40  and conveyed by the communication network  30  (Step “S 72 ”), and transfers the call to the hands-free apparatus  20  through the control channel (Step “S 73 ”). The hands-free apparatus  20  receives the call with the antenna  21  and the radio circuit  22 .  
         [0073]     The hands-free control circuit  24  measures time after receiving the call (Step “S 74 ”). When a period of the measured time reaches a predetermined time period while the call is not accepted with the operation device  23  (“YES” of Step “S 75 ”), the hands-free control circuit requests the radio apparatus  10  to start to send a reply message to the second ending node  40  (Step “S 76 ”). The radio apparatus  10  then reads the reply message out of its memory and starts to send (Step “S 77 ”).  
         [0074]     While the reply message is being sent (Step “S 78 ”), the call has been neither accepted nor rejected yet. When the call is accepted with the operation device  23  in the meantime (“YES” of Step “S 79 ”), the hands-free control circuit  24  exchanges data necessary to establish a voice channel with the radio apparatus  10 , according to a specified protocol of the local radio link. Local radio signals carrying those data are sent and received with the radio circuit  22  and the antenna  21 . As the result a voice channel is established (Step “S 80 ”).  
         [0075]     Once the voice channel is established on the local radio link, a hands-free voice communication is conducted between the second ending node  40  and the hands-free system  1  (Step “S 81 ”) as described in the first embodiment.  
         [0076]     When the call is accepted with the operation device  23  before the measured time reaches the predetermined time period (“NO” of Step “S 75 ”), the hands-free apparatus  20  and the radio apparatus  10  establish the voice channel (Step “S 80 ”) as described above. This sequence goes through a circled “E” as illustrated in  FIG. 3 .  
         [0077]     When the call is not accepted with the operation device  23  before sending the reply message ends (“NO” of Step “S 79 ”), the hands-free control circuit  24  requests the radio apparatus  10  to reject the call and goes back to the status of waiting for an arriving call before Step “S 72 ”. This sequence goes through a circled “F” as illustrated in  FIG. 7 .  
         [0078]     According to the fourth embodiment described above, the hands-free system may be controlled by the hands-free apparatus and obtains the same effect as in the first embodiment.  
         [0079]     A fifth embodiment of the present invention will now be described with reference to  FIG. 8 .  FIG. 1  and  FIG. 6  will also be referenced as a hands-free system in the fifth embodiment has the same configuration as the one in the fourth embodiment shown in  FIG. 1  and  FIG. 6 . The same reference numerals given to the apparatuses, components or circuits in these figures will be used in the following description, and a detailed explanation of these is omitted.  
         [0080]      FIG. 8  is a diagram of a processing sequence and signal flows among the second ending node  40 , the radio apparatus  10 , and the hands-free apparatus  20  of the fifth embodiment. Steps “S 71 ” through “S 74 ” are the same as those in  FIG. 7 , and a detailed explanation of these steps is omitted.  
         [0081]     While measuring time (Step “S 74 ”), the hands-free control circuit  24  exchanges data necessary to establish a voice channel in advance according to a specified protocol, with the radio apparatus  10 , and establish the voice channel on the local radio link (Step “S 85 ”). The voice channel established in advance is identical to the voice channel in the fourth embodiment, and is used to transfer sounds as well as voice messages.  
         [0082]     The radio apparatus  10  sends a ringing sound read out of its memory through the voice channel to the hands-free apparatus  20  (Step “S 86 ”). The ringing sound is received by the antenna  21  and the radio circuit  22 , and the hands-free control circuit controls reproducing the ringing sound by, e.g., driving the loud speaker.  
         [0083]     When a period of the measured time reaches a predetermined time period while the call is not accepted with the operation device  23  (“YES” of Step “S 87 ”), the hands-free control circuit  24  releases the voice channel with the radio apparatus  10  (Step “S 88 ”). Then the hands-free control circuit  24  requests the radio apparatus  10  to start to send a reply message to the second ending node  40  (Step “S 89 ”). The radio apparatus  10  then reads the reply message out of its memory and starts to send (Step “S 90 ”).  
         [0084]     The following Steps “S 91 ”, “YES” of “S 92 ”, “S 93 ” and “S 94 ” are identical to the Steps “S 78 ”, “YES” of “S 79 ”, “S 80 ” and “S 81 ”, respectively, and a detailed explanation of these is omitted.  
         [0085]     When the call is accepted with the operation device  23  before the measured time reaches the predetermined time period (“NO” of Step “S 87 ”), the sequence goes through a circled “G” as illustrated in  FIG. 8 , and a detailed explanation of which will be described later as another embodiment of the present invention.  
         [0086]     When the call is not accepted with the operation device  23  before sending the reply message ends (“NO” of Step “S 92 ”), the hands-free control circuit  24  requests the radio apparatus  10  to reject the call and goes back to the status of waiting for an arriving call before Step “S 72 ”. This sequence goes through a circled “H” as illustrated in  FIG. 8 .  
         [0087]     According to the fifth embodiment described above, the hands-free system may be controlled by the hands-free apparatus and obtains the same effect as in the second embodiment.  
         [0088]     A sixth embodiment of the present invention will now be described with reference to  FIG. 9 .  FIG. 1  and  FIG. 6  will also be referenced since a hands-free system in the sixth embodiment has the same configuration as the one in the fourth embodiment shown in  FIG. 1  and  FIG. 6 . The same reference numerals given to the apparatuses, components or circuits in these figures will be used in the following description, and a detailed explanation of these is omitted.  
         [0089]      FIG. 9  is a diagram of a processing sequence and signal flows among the second ending node  40 , the radio apparatus  10 , and the hands-free apparatus  20  of the third embodiment. Steps “S 71 ” through “S 74 ”, “S 85 ”, “S 86 ”, “YES” of “S 87 ”, “S 88 ” through “S 93 ” and “S 94 ” are the same as those in  FIG. 8 , and a detailed explanation of these steps is omitted.  
         [0090]     When the call is accepted with the operation device  23  before the measured time reaches the predetermined time period (“NO” of Step “S 87 , and Step “S 87   a ”), the hands-free apparatus  20  and the radio apparatus  10  maintain the voice channel established at Step “S 85 ” and conduct the hands-free voice communication of Step “S 94 ” using the voice channel.  
         [0091]     According to the sixth embodiment described above, the hands-free system may be controlled by the hands-free apparatus and obtains the same effect as in the third embodiment.  
         [0092]     The particular hardware or software implementation of the present invention may be varied while still remaining within the scope of the present invention. It is therefore to be understood that within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described herein.