Patent Publication Number: US-RE48232-E

Title: Method for controlling cordless telephone device, handset of cordless telephone device, and cordless telephone device

Description:
This application is a reissue of U.S. Pat. No. 9,280,314, which issued on Mar. 8, 2016 from application Ser. No. 14/514,659, which claims the benefit of U.S. Provisional Application No. 61/892,179, filed Oct. 17, 2013.  
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a technique for controlling a cordless telephone device for use in a system that allows remote control of a home electric appliance in accordance with voice instructions of a user. 
     2. Description of the Related Art 
     Recent advancements in communication technology enable remote control of a home electric appliance by using voice instructions of a user (see Japanese Unexamined Patent Application Publication No. 6-152768 and Japanese Unexamined Patent Application Publication No. 7-30675). The techniques disclosed in Japanese Unexamined Patent Application Publication No. 6-152768 (hereinafter referred to as “Patent Literature 1”) and Japanese Unexamined Patent Application Publication No. 7-30675 (hereinafter referred to as “Patent Literature 2”) allow a user to input a specific code or password to a handset of a cordless telephone device to set the operation mode of a base unit of the cordless telephone device to a speech recognition mode. The base unit executes various processes for remote control of a home electric appliance in the speech recognition mode. 
     SUMMARY 
     However, further improvements are needed in the techniques disclosed in Patent Literature 1 and Patent Literature 2. 
     In one general aspect, the techniques disclosed here feature a method for controlling a cordless telephone device including a base unit and a handset, for use in a system that allows remote control of a home electric appliance by using voice instructions of a user. The method includes a first generation step of causing a first generation unit included in the handset to generate a first stream by encoding audio input via a sound receiving unit included in the handset, and a first transmission step of transmitting the first stream to the base unit. The first generation step includes causing the first generation unit to generate instruction bit information indicating that the audio represents the voice instructions and to generate, as the first stream, a first instruction stream indicative of the voice instructions in a case where a first trigger indicating a request to start the remote control of the home electric appliance is given to the first generation unit. The first transmission step includes transmitting the instruction bit information and the first instruction stream to the base unit through a common multiplexing scheme that is common to transmission of the first stream generated in a case where the first trigger is not given to the first generation unit. These general and specific aspects may be implemented using a system, a method, and a computer program, and any combination of systems, methods, and computer programs. 
     Embodiments of the present disclosure may enable easy switching between a call mode in which a user makes a telephone call and a remote control mode in which a user takes remote control of a home electric appliance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic block diagram of a cordless telephone device according to Embodiment 1; 
         FIG. 2  is a schematic flowchart of an illustrative control method for the cordless telephone device illustrated in  FIG. 1  (Embodiment 2); 
         FIG. 3  is a schematic flowchart of an illustrative control method for the cordless telephone device illustrated in  FIG. 1  (Embodiment 3); 
         FIG. 4  is a schematic block diagram of a cordless telephone device according to Embodiment 4; 
         FIG. 5  is a schematic block diagram of a telephone handset according to Embodiment 5; 
         FIG. 6  is a schematic timing chart depicting an illustrative operation of the telephone handset illustrated in  FIG. 5  (Embodiment 6); 
         FIG. 7  is a schematic block diagram of a telephone handset according to Embodiment 7; 
         FIG. 8  is a conceptual diagram of a control system according to Embodiment 8; 
         FIG. 9  is a schematic block diagram of a wearable terminal according to Embodiment 9; 
         FIG. 10  is a conceptual diagram of a control system according to Embodiment 10; 
         FIG. 11  is a conceptual diagram of a control system according to Embodiment 11; 
         FIG. 12  is a conceptual diagram of a control system according to Embodiment 12; 
         FIG. 13  is a schematic block diagram of a wearable terminal according to Embodiment 13; 
         FIG. 14  is a conceptual diagram of a control system according to Embodiment 14; 
         FIG. 15  is a conceptual diagram illustrating a use environment of the wearable terminal illustrated in  FIG. 14 ; 
         FIG. 16  is a schematic block diagram of a wearable terminal according to Embodiment 15; 
         FIG. 17  is a conceptual diagram of a control system according to Embodiment 16; 
         FIG. 18A  is a conceptual diagram illustrating a use environment of a wearable terminal in the control system illustrated in  FIG. 17 ; 
         FIG. 18B  is a conceptual diagram illustrating a use environment of the wearable terminal in the control system illustrated in  FIG. 17 ; 
         FIG. 19  is a schematic block diagram of a cordless telephone device according to Embodiment 17; 
         FIG. 20  is a schematic flowchart of an illustrative control method for a base unit of the cordless telephone device illustrated in  FIG. 19  (Embodiment 18); 
         FIG. 21  is a schematic block diagram of a base unit according to Embodiment 19; 
         FIG. 22  is a schematic flowchart of an illustrative control method for the base unit illustrated in  FIG. 21  (Embodiment 20); 
         FIG. 23  is a schematic flowchart of control of switching to a mute mode, which is executed by the base unit illustrated in  FIG. 21  (Embodiment 21); 
         FIG. 24  is a schematic block diagram of a base unit according to Embodiment 22; 
         FIG. 25  is a schematic block diagram of a base unit according to Embodiment 23; 
         FIG. 26A  is a conceptual diagram of a control system according to Embodiment 24; 
         FIG. 26B  is a schematic block diagram of a base unit in the control system illustrated in  FIG. 26A ; 
         FIG. 27  is a conceptual diagram of a control system according to Embodiment 25; 
         FIG. 28  is a table showing illustrative data stored in a target device database in the control system illustrated in  FIG. 27 ; 
         FIG. 29  is a schematic block diagram of a wearable terminal according to Embodiment 26; 
         FIG. 30  is a conceptual diagram of a control system including the wearable terminal illustrated in  FIG. 29 ; 
         FIG. 31  is a table showing illustrative data stored in a target device database in the control system illustrated in  FIG. 30 ; 
         FIG. 32  is a conceptual diagram of a method for using the control system illustrated in  FIG. 8  (Embodiment 27); 
         FIG. 33  is a schematic block diagram of a wearable terminal according to Embodiment 28; 
         FIG. 34  is a schematic block diagram of a base unit according to Embodiment 29; 
         FIG. 35  is a conceptual diagram of a control system according to Embodiment 30; 
         FIG. 36  is a schematic block diagram of a wearable terminal according to Embodiment 31; 
         FIG. 37  is a conceptual diagram of a three-dimensional coordinate system that is set for a user&#39;s upper limb; and 
         FIG. 38  is a table showing illustrative relationships between operations demanded by a user and operations performed on a wearable terminal. 
     
    
    
     DETAILED DESCRIPTION 
     Findings on which the Present Disclosure is Based 
     The inventor has found that the techniques disclosed in Patent Literature 1 and Patent Literature 2 given above have the following difficulties. 
     The techniques disclosed in Patent Literature 1 and Patent Literature 2 require, between the handset and the base unit, a line used only for telephone calls or conversations and a line used only for remote control of home electric appliances. This increases the complexity of the design required by a control system for controlling home electric appliances, and also increases construction cost for the control system. 
     To address the problems described above, the inventor has developed the following solution. 
     A first aspect of the present disclosure provides a method for controlling a cordless telephone device including a base unit and a handset, for use in a system that allows remote control of a home electric appliance by using voice instructions of a user. The method includes a first generation step of causing a first generation unit included in the handset to generate a first stream by encoding audio input via a sound receiving unit included in the handset, and a first transmission step of transmitting the first stream to the base unit. The first generation step includes causing the first generation unit to generate instruction bit information indicating that the audio represents the voice instructions and to generate, as the first stream, a first instruction stream indicative of the voice instructions in a case where a first trigger indicating a request to start the remote control of the home electric appliance is given to the first generation unit. The first transmission step includes transmitting the instruction bit information and the first instruction stream to the base unit through a common multiplexing scheme that is common to transmission of a first stream generated in a case where the first trigger is not given. 
     According to this aspect, instruction bit information and a first instruction stream are transmitted to a base unit through a common multiplexing scheme that is common to transmission of a first stream generated in a case where the first trigger is not given. Thus, the user may be able to easily switch the operation mode of the cordless telephone device between the call mode and the remote control mode. 
     In the first aspect, the common multiplexing scheme may be a Time Division Duplex/Time Division Multiple Access (TDD-TDMA) scheme complying with a Digital Enhanced Cordless Telecommunications (DECT) standard. 
     According to this aspect, the common multiplexing scheme is a TDD-TDMA scheme complying with a DECT standard. Thus, a system for the remote control of a home electric appliance may be easily constructed. 
     In the first aspect, in a case where the first trigger is not given to the first generation unit, the first generation step may include causing the first generation unit to generate call bit information indicating that the audio represents a voice call and to generate, as the first stream, a first call stream indicative of the audio. 
     According to this aspect, the first generation unit generates call bit information. Thus, the base unit may be able to accurately determine whether or not the user wishes to enter a remote control mode, preventing or reducing erroneous switching of the operation mode of the cordless telephone device. 
     In the first aspect, the first generation step may include, in a case where the first generation unit receives the first trigger during generation of the first call stream, causing the first generation unit to generate the instruction bit information and the first instruction stream, and causing the first generation unit to switch an operation mode of the cordless telephone device from a call mode in which the audio is transferred to an intended party with which the user is engaged in the voice call to a mute mode in which transfer of the audio to the intended party is interrupted. 
     According to this aspect, upon receipt of the first trigger during the generation of a first call stream, the first generation unit switches the operation mode of the cordless telephone device from a call mode in which audio is transferred to the intended party to a mute mode in which transfer of the audio to the intended party is interrupted. Thus, the voice instructions given to the cordless telephone device may be less likely to be delivered to the intended party. This may enable the user to easily switch the operation mode of the cordless telephone device from the call mode to the remote control mode even during a telephone conversation. 
     In the first aspect, the first generation step may include causing the first generation unit to generate, during the mute mode, an alternative stream representing an alternative sound that replaces the audio. The first transmission step may include transmitting the alternative stream to the base unit through the common multiplexing scheme. 
     According to this aspect, an alternative stream is transmitted to the base unit. Thus, the intended party may be able to hear an alternative sound during the mute mode. Accordingly, the intended party may be able to recognize that the connection with the cordless telephone device is ongoing. 
     In the first aspect, the first generation step may include, in a case where the first generation unit receives a second trigger indicating a request to return to the call mode, (i) causing the first generation unit to terminate the mute mode, and (ii) causing the first generation unit to generate the call bit information and the first call stream. 
     According to this aspect, the user may be able to easily return the operation mode of the cordless telephone device from the remote control mode to the call mode during a telephone conversation. 
     In the first aspect, the first generation step may include, after a certain period has elapsed since the mute mode began, (i) causing the first generation unit to terminate the mute mode, and (ii) causing the first generation unit to generate the call bit information and the first call stream. 
     According to this aspect, the user may be able to easily return the operation mode of the cordless telephone device from the remote control mode to the call mode during a telephone conversation. 
     In the first aspect, the first generation step may include causing the first generation unit to generate, as the call bit information, information specifying an audio encoding scheme for the first call stream. 
     According to this aspect, the first call stream may be appropriately encoded using the audio encoding scheme specified in the call bit information. 
     In the first aspect, the first generation step may include causing the first generation unit to generate, as the call bit information, information specifying a bit rate for the first call stream. 
     According to this aspect, the first call stream may be appropriately encoded at the bit rate specified in the call bit information. 
     In the first aspect, the first generation step may include causing the first generation unit to generate, as the instruction bit information, information specifying an audio encoding scheme for the first instruction stream. 
     According to this aspect, the first instruction stream may be appropriately encoded using the audio encoding scheme specified in the instruction bit information. 
     In the first aspect, the first generation step may include causing the first generation unit to generate, as the instruction bit information, information specifying a bit rate for the first instruction stream. 
     According to this aspect, the first instruction stream may be appropriately encoded at the bit rate specified in the instruction bit information. 
     In the first aspect, the first generation step may include causing the first generation unit to encode the first instruction stream and the first call stream at a bit rate complying with the DECT standard using an audio encoding scheme complying with the DECT standard. 
     According to this aspect, the first instruction stream and the first call stream may be appropriately encoded at a bit rate complying with the DECT standard using an audio encoding scheme complying with the DECT standard. 
     In the first aspect, the first trigger may be given to the first generation unit by predetermined movement given to the handset, predetermined audio given to the handset, or a predetermined operation given to the handset. 
     According to this aspect, the user may be able to give predetermined movement, predetermined audio, or a predetermined operation to the handset to easily switch the operation mode of the cordless telephone device. 
     In the first aspect, the method may further include a second generation step of generating a second stream corresponding to the first stream transmitted from the handset to the base unit, and a second transmission step of transmitting the second stream. The second generation step may include (i) in a case where the base unit receives the instruction bit information and the first instruction stream, causing the base unit to generate a second instruction stream corresponding to the first instruction stream, and (ii) in a case where the base unit receives the call bit information and the first call stream, causing the base unit to generate a second call stream corresponding to the first call stream. The second transmission step may include (iii) in a case where the base unit generates the second instruction stream, causing the base unit to transmit the second instruction stream to a server that generates a control command using the second instruction stream for controlling the home electric appliance, and (iv) in a case where the base unit generates the second call stream, transmitting the second call stream to a telephone of the intended party. 
     According to this aspect, the base unit generates a second instruction stream corresponding to the first instruction stream in accordance with receipt of the instruction bit information and the first instruction stream. Thus, the user may be able to appropriately operate the home electric appliance in accordance with audio from the user. The base unit generates a second call stream corresponding to the first call stream in accordance with receipt of the call bit information and the first call stream. Thus, the user may be able to appropriately have a conversation with the intended party. 
     In the first aspect, the second transmission step may include causing the base unit to selectively transmit the second instruction stream or the second call stream via a public communication line that is common to transmission of the second instruction stream and the second call stream. 
     According to this aspect, the base unit selectively transmits the second instruction stream or the second call stream via a public communication line that is common to transmission of the second instruction stream and the second call stream. Thus, a simple connection may be made between the cordless telephone device and the public communication line. 
     In the first aspect, the second transmission step may include (i) in a case where the base unit generates the second instruction stream, causing the base unit to transmit the second instruction stream via a first public communication line, and (ii) in a case where the base unit generates the second call stream, causing the base unit to transmit the second call stream via a second public communication line different from the first public communication line. 
     According to this aspect, the base unit that generates a second call stream transmits the second call stream via a second public communication line different from a first public communication line. Thus, the user may be able to select a public communication line suitable for the transmission of the second instruction stream as a first public communication line, and to select a public communication line suitable for the second call stream as a second public communication line. 
     In the first aspect, the second generation step may include causing the base unit to generate, during the mute mode, an alternative stream representing an alternative sound that replaces the audio. The second transmission step may include, in a case where the base unit generates the alternative stream, transmitting the alternative stream to the telephone of the intended party. 
     According to this aspect, an alternative stream is transmitted to the telephone of the intended party. Thus, the intended party may be able to hear an alternative sound during the mute mode. Accordingly, the intended party may be able to recognize that the connection with the cordless telephone device is ongoing. 
     A second aspect of the present disclosure provides a handset of a cordless telephone device for use in a system that allows remote control of a home electric appliance by using voice instructions of a user. The handset includes a sound receiving unit configured to receive audio of the user, a first generation unit configured to generate a first stream by encoding the audio input via the sound receiving unit, and a first transmission unit configured to transmit the first stream to a base unit of the cordless telephone device. The first generation unit is configured to generate instruction bit information indicating that the audio represents the voice instructions and to generate, as the first stream, a first instruction stream indicative of the voice instructions in accordance with a first trigger indicating a request to start the remote control of the home electric appliance. The first transmission unit is configured to transmit the instruction bit information and the first instruction stream to the base unit through a common multiplexing scheme that is common to transmission of a first stream generated in a case where the first trigger is not given to the first generation unit. 
     According to this aspect, instruction bit information and a first instruction stream are transmitted to a base unit through a common multiplexing scheme that is common to transmission of a first stream generated in a case where the first trigger is not given. Thus, the user may be able to easily switch the operation mode of the cordless telephone device between the call mode and the remote control mode. 
     In the second aspect, in a case where the first trigger is not given to the first generation unit, the first generation unit may be configured to generate call bit information indicating that the audio represents a voice call and to generate, as the first stream, a first call stream indicative of the audio. 
     According to this aspect, the first generation unit generates call bit information. Thus, the base unit may be able to accurately determine whether or not the user wishes to enter a remote control mode, preventing or reducing erroneous switching of the operation mode of the cordless telephone device. 
     In the second aspect, the handset may further include a trigger generation unit configured to give the first trigger to the first generation unit. 
     According to this aspect, the handset includes a trigger generation unit. Thus, the user may be able to operate the handset to easily switch the operation mode of the cordless telephone device between the call mode and the remote control mode. 
     A third aspect of the present disclosure provides a cordless telephone device including the handset described above and a base unit. The base unit includes (i) a second generation unit configured to generate a second instruction stream corresponding to the first instruction stream in accordance with receipt of the instruction bit information and the first instruction stream, and configured to generate a second call stream corresponding to the first call stream in accordance with receipt of the call bit information and the first call stream, and (ii) a second transmission unit configured to transmit the second instruction stream to a server that generates a control command using the second instruction stream for controlling the home electric appliance, and configured to transmit the second call stream to a telephone of an intended party with which the user is engaged in the voice call. 
     According to this aspect, the base unit generates a second instruction stream corresponding to the first instruction stream in accordance with receipt of the instruction bit information and the first instruction stream. Thus, the home electric appliance may appropriately operate in accordance with the audio from the user. The base unit generates a second call stream corresponding to the first call stream in accordance with receipt of the call bit information and the first call stream. Thus, the user may be able to appropriately have a conversation with the intended party. 
     Some embodiments relating to a technique for controlling a home electrical device using a cordless telephone device will be described hereinafter with reference to the accompanying drawings. The technique for controlling a home electrical device using a cordless telephone device will be apparently understood from the following description. Note that the direction associated with the terms “up”, “down”, “left”, “right”, etc. is for descriptive purposes only and is intended to be broadly construed. 
     Embodiment 1 
     As described above, existing control techniques using a cordless telephone device require, between the handset and the base unit, a line used only for telephone calls or conversations and a line used only for remote control of home electric appliances. No extremely complicated design of a control system for controlling a home electric appliance is required when a stream representing audio of a telephone conversation and a stream representing audio for remote control of a home electric appliance are transferred from the handset to the base unit using a common multiplexing scheme constructed between the handset and the base unit. This may result in a reduction in the construction cost for the control system. In Embodiment 1, a description will be given of a technique for transferring a stream representing audio of a telephone conversation and a stream representing audio for remote control of a home electric appliance from the handset to the base unit using a common multiplexing scheme constructed between the handset and the base unit. 
       FIG. 1  is a schematic block diagram of a cordless telephone device  100  according to Embodiment 1. The cordless telephone device  100  will be described with reference to  FIG. 1 . 
     The cordless telephone device  100  includes a base unit  200  and a handset  300 . As with a typical cordless telephone device, a user is able to input audio to the base unit  200  or the handset  300  and to have a conversation with an intended party ITP. 
     The user may give voice instructions for remote control of a home electric appliance APL to the handset  300 . The voice instructions are transferred from the handset  300  to the base unit  200 . After that, the voice instructions are transferred from the base unit  200  to the home electric appliance APL via a server SVR. The home electric appliance APL operates in accordance with the voice instructions. Accordingly, the cordless telephone device  100  can function as part of a system that executes remote control of the home electric appliance APL. 
     The handset  300  includes a sound receiving unit  310 , a generation unit  320 , and a transmission unit  330 . The user provides audio to the sound receiving unit  310 . The sound receiving unit  310  receives the audio and converts it into an electrical signal. The sound receiving unit  310  may be a built-in microphone of a typical telephone. Alternatively, the sound receiving unit  310  may be any other device configured to convert the audio of the user into an electrical signal. The basic concept of this embodiment is not limited to a specific device used for the sound receiving unit  310 . 
     The electrical signal is output from the sound receiving unit  310  to the generation unit  320 . The generation unit  320  applies an encoding process to the electrical signal, and generates a stream representing the audio of the user. In this embodiment, the first generation unit is exemplified by the generation unit  320 . The first stream is exemplified by the stream generated by the generation unit  320 . 
     The encoding process may be based on an encoding technique used by a typical cordless telephone device. For example, the generation unit  320  may execute an encoding process using an audio encoding scheme complying with the digital enhanced cordless telecommunications (DECT) standard. Additionally, the generation unit  320  may execute an encoding process at a bit rate complying with the DECT standard. Alternatively, the generation unit  320  may perform an encoding process using any other audio encoding technique. The basic concept of this embodiment is not limited to a specific encoding process executed by the generation unit  320 . 
     The stream is output from the generation unit  320  to the transmission unit  330 . After that, the transmission unit  330  transmits the stream to the base unit  200 . In this embodiment, the first transmission unit is exemplified by the transmission unit  330 . 
     The user may give a trigger to the handset  300  for requesting the start of the remote control of the home electric appliance APL. The user may perform a predetermined operation on the handset  300  to request the start of the remote control of the home electric appliance APL. Alternatively, the user may give predetermined movement to the handset  300  to request the start of the remote control of the home electric appliance APL. Further alternatively, the user may provide predetermined audio to the handset  300  to request the start of the remote control of the home electric appliance APL. The basic concept of this embodiment is not limited to a specific method for requesting the start of the remote control of the home electric appliance APL. In this embodiment, the first trigger is exemplified by the trigger given by the user to the handset  300 . 
     When the user gives a trigger to the handset  300  in the way described above, the generation unit  320  generates instruction bit information in accordance with the trigger. The generation unit  320  generates, as the stream described above, an instruction stream from the electrical signal representing the audio received by the sound receiving unit  310  after the trigger (voice instructions for the home electric appliance APL) was given. In this embodiment, the first instruction stream is exemplified by the instruction stream generated by the generation unit  320 . 
     Similarly to a stream generated by the generation unit  320  when the user does not give a trigger to the handset  300 , the instruction bit information and the instruction stream are transmitted from the generation unit  320  to the base unit  200  via the transmission unit  330 . The instruction bit information and the instruction stream are transmitted from the transmission unit  330  to the base unit  200  using a multiplexing scheme that is common to the transmission of the stream generated by the generation unit  320  when the user does not give a trigger to the handset  300 . Thus, no extremely complicated design of a control system for controlling the home electric appliance APL is required. 
     A common multiplexing scheme constructed between the handset  300  and the base unit  200  may be a time division duplex/time division multiple access (TDD-TDMA) scheme complying with the DECT standard. Alternatively, any other multiplexing scheme may be constructed between the handset  300  and the base unit  200 . The basic concept of this embodiment is not limited to a specific multiplexing scheme. 
     When the base unit  200  receives the instruction bit information, the base unit  200  may determine that the stream received together with the instruction bit information is an instruction stream representing voice instructions for the home electric appliance APL. In this case, the base unit  200  communicates with the home electric appliance APL via the server SVR. 
     When the base unit  200  does not receive the instruction bit information, the base unit  200  may determine that the stream received from the handset  300  represents the content of a conversation with the intended party ITP. In this case, the base unit  200  communicates with the telephone of the intended party ITP. 
     Embodiment 2 
     The cordless telephone device described in connection with Embodiment 1 is configured to operate under various forms of control. In Embodiment 2, a description will be given of an illustrative control method for the cordless telephone device. 
       FIG. 2  is a schematic flowchart of an illustrative control method for the cordless telephone device  100 . A control method for the cordless telephone device  100  will be described with reference to  FIG. 1  and  FIG. 2 . 
     Step S 110   
     In step S 110 , the generation unit  320  executes an encoding process on an electrical signal representing audio input via the sound receiving unit  310 , and generates a stream. When the user gives a trigger to the handset  300 , the generation unit  320  generates instruction bit information and also generates an instruction stream as a stream. After the generation unit  320  generates the stream, step S 120  is executed. In this embodiment, the first generation step is exemplified by step S 110 . 
     Step S 120   
     In step S 120 , the stream is transmitted from the generation unit  320  to the base unit  200  via the transmission unit  330 . If the generation unit  320  generates instruction bit information and an instruction stream in step S 110 , the instruction bit information and the instruction stream are output from the generation unit  320  to the transmission unit  330 . The instruction bit information and the instruction stream are transmitted from the transmission unit  330  to the base unit  200  through a multiplexing scheme. A multiplexing scheme that is common to a stream generated by the generation unit  320  when the user does not give a trigger to the handset  300  is used for the transmission of the instruction bit information and the instruction stream from the transmission unit  330  to the base unit  200 . In this embodiment, the first transmission step is exemplified by step S 120 . 
     Embodiment 3 
     The handset may also generate bit information when the user does not give a trigger to the handset. This allows the base unit to accurately determine whether the stream transmitted from the handset represents the content of a conversation with the intended party or voice instructions for a home electric appliance. In Embodiment 3, a description will be given of a control technique for generating a plurality of types of bit information. 
       FIG. 3  is a schematic flowchart of an illustrative control method for the cordless telephone device  100 . A control method for the cordless telephone device  100  will be described with reference to  FIG. 1  and  FIG. 3 . 
     Step S 210   
     In step S 210 , the user determines whether to give voice instructions to the home electric appliance APL or to have a conversation with an intended party. The user who gives voice instructions to the home electric appliance APL gives a trigger to the handset  300 . When the user gives a trigger to the handset  300 , step S 220  is executed. Otherwise, step S 230  is executed. 
     Step S 220   
     In step S 220 , the generation unit  320  generates instruction bit information and an instruction stream. Then, step S 240  is executed. The generation unit  320  may generate an instruction stream using an audio encoding scheme complying with the DECT standard. The generation unit  320  may generate an instruction stream at a bit rate complying with the DECT standard. In this embodiment, the first generation step is exemplified by step S 220 . 
     Step S 230   
     In step S 230 , the generation unit  320  generates call bit information and a call stream. The generation unit  320  may generate a call stream using an audio encoding scheme complying with the DECT standard. The generation unit  320  may generate a call stream at a bit rate complying with the DECT standard. Unlike the instruction bit information, the call bit information indicates that the audio received by the sound receiving unit  310  is a voice call with the intended party ITP. Unlike the instruction stream, the call stream represents the audio of a conversation with the intended party ITP. After the generation of call bit information and a call stream, step S 240  is executed. In this embodiment, the first generation step is exemplified by step S 230 . 
     Step S 240   
     In step S 240 , the stream is output from the generation unit  320  to the transmission unit  330 . The instruction bit information and the instruction stream are transmitted from the transmission unit  330  to the base unit  200  through a multiplexing scheme that is common to the call bit information and the call stream. 
     Embodiment 4 
     The handset of the cordless telephone device may have a function to generate a trigger signal as to whether or not the user is going to take remote control of a home electric appliance. In Embodiment 4, a description will be given of a cordless telephone device including a handset configured to generate a trigger signal. 
       FIG. 4  is a schematic block diagram of a cordless telephone device  100 A according to Embodiment 4. The cordless telephone device  100 A will be described with reference to  FIG. 4 . Numerals common to Embodiment 1 and Embodiment 4 designate components having substantially the same function as those in Embodiment 1. These components are thus identified using the description made in Embodiment 1. 
     The cordless telephone device  100 A includes a base unit  200 . The base unit  200  is identified using the description made in Embodiment 1. 
     The cordless telephone device  100 A further includes a handset  300 A. The handset  300 A may selectively generate a pair of instruction bit information and an instruction stream or a pair of call bit information and a call stream in accordance with the technique described in connection with Embodiment 3. The pair of instruction bit information and an instruction stream and the pair of call bit information and a call stream are transmitted from the handset  300 A to the base unit  200  through a common multiplexing scheme. 
     Similarly to Embodiment 1, the handset  300 A includes a sound receiving unit  310  and a transmission unit  330 . These components are identified using the description made in Embodiment 1. 
     The handset  300 A further includes a stream generation unit  320 A and a trigger signal generation unit  340 . When the user gives a trigger to the handset  300 A, the trigger signal generation unit  340  generates a trigger signal. The trigger signal is output from the trigger signal generation unit  340  to the stream generation unit  320 A. The stream generation unit  320 A generates instruction bit information in accordance with the trigger signal. After that, the stream generation unit  320 A applies an encoding process to the electrical signal received from the sound receiving unit  310  to generate an instruction stream. The instruction bit information and the instruction stream are output from the stream generation unit  320 A to the transmission unit  330 . In this embodiment, the first generation unit is exemplified by the stream generation unit  320 A. The first trigger is exemplified by the trigger signal. 
     When the stream generation unit  320 A does not receive a trigger signal but receives the electrical signal from the sound receiving unit  310 , the stream generation unit  320 A generates call bit information and a call stream. The call bit information and the call stream are output from the stream generation unit  320 A to the transmission unit  330 . 
     The trigger signal generation unit  340  may be an operation button (e.g., a power button) or any other operation portion that appears on a housing (not illustrated) of the handset  300 A. In this case, the user who wishes to take remote control of the home electric appliance APL is able to operate the operation portion functioning as the trigger signal generation unit  340  to generate a trigger signal. 
     The trigger signal generation unit  340  may be an acceleration sensor, an angular velocity sensor, or any other sensor element configured to detect movement given to the handset  300 A. In this case, the user who wishes to take remote control of the home electric appliance APL is able to activate the handset  300 A to generate a trigger signal. 
     The trigger signal generation unit  340  may have a function to recognize audio. In this case, the trigger signal generation unit  340  may be electrically connected to the sound receiving unit  310 . The trigger signal generation unit  340  may analyze the electrical signal converted from the audio of the user by the sound receiving unit  310 , and generate a trigger signal when the electrical signal indicates specific audio. 
     Embodiment 5 
     The designer may be able to design various devices on the basis of the design principles of the handset described in connection with Embodiment 4. The designer may design a handset having a shape and function similar to those of the telephone handset of a typical cordless telephone. Alternatively, the designer may design a wearable terminal such as a terminal that looks like a watch or a terminal that looks like a pendant. In Embodiment 5, a description will be given of a handset having a shape and function similar to those of the telephone handset of a typical cordless telephone. 
       FIG. 5  is a schematic block diagram of a telephone handset  300 B according to Embodiment 5. The telephone handset  300 B will be described with reference to  FIG. 4  and  FIG. 5 . 
     Similarly to the telephone handset of a typical cordless telephone device, the telephone handset  300 B has a function to transmit the audio of the user to the base unit as a radio wave, and a function to receive a radio wave representing the audio of the intended party from the base unit and to output the audio of the intended party. In addition to the functions described above, the telephone handset  300 B has a function to process audio for the remote control of a home electric appliance. 
     The telephone handset  300 B includes a signal conversion unit  310 B, an integrated circuit  320 B, an antenna unit  331 , a power button  340 B, and a power supply unit  350 . The user may operate the power button  340 B to request supply of power from the power supply unit  350 . As a result, power is supplied from the power supply unit  350  to the signal conversion unit  310 B and the integrated circuit  320 B. After that, the user is able to have a conversation with an intended party or to take remote control of a home electric appliance. 
     The signal conversion unit  310 B includes input keys  311 , a speaker  312 , and a microphone  313 . The input keys  311  may be number keys (or a ten-key pad) of the telephone handset of a typical cordless telephone device. The user may operate the input keys  311  to input the telephone number of the intended party. The input telephone number is output to the integrated circuit  320 B as an electrical signal. The integrated circuit  320 B processes an electrical signal representing the telephone number, and transmits a radio wave representing the telephone number from the antenna unit  331  to the base unit. The processing of the electrical signal generated by the input keys  311  may be based on a processing technique performed by the telephone handset of a typical cordless telephone device. The basic concept of this embodiment is not limited to a specific process performed on the electrical signal generated by the operation of the input keys  311 . 
     The antenna unit  331  receives the radio wave representing the audio of the intended party. After that, the integrated circuit  320 B processes the radio wave, and generates an electrical signal representing the audio of the intended party. After that, the electrical signal is output from the integrated circuit  320 B to the speaker  312 . The speaker  312  converts the electrical signal from the integrated circuit  320 B into audio. As a result, the audio of the intended party is reproduced from the speaker  312 . A signal processing technique and reproduction technique for the reproduction of the audio of the intended party may be based on a processing technique performed by the telephone handset of a typical cordless telephone device. The basic concept of this embodiment is not limited to a specific technique for the reproduction of the audio of the intended party. 
     The microphone  313  converts the audio of the user into an electrical signal. The microphone  313  may have substantially the same structure as a built-in microphone of the telephone handset of a typical cordless telephone device. The basic concept of this embodiment is not limited to a specific structure of the microphone  313 . The microphone  313  corresponds to the sound receiving unit  310  described with reference to  FIG. 4 . 
     The integrated circuit  320 B includes a control unit  321 , an encoding unit  322 , an input/output (I/O) section  323 , and a communication unit  332 . The control unit  321  controls the overall operation of the integrated circuit  320 B. Accordingly, the encoding unit  322 , the I/O section  323 , and the communication unit  332  operate under control of the control unit  321 . 
     When the user operates the power button  340 B (e.g., when the user presses the power button  340 B for a short period of time) while the power supply unit  350  supplies power to the signal conversion unit  310 B and the integrated circuit  320 B, the trigger signal is output from the power button  340 B to the control unit  321 . The control unit  321  generates instruction bit information in accordance with the trigger signal. The instruction bit information may include information specifying an audio encoding scheme to be used for the encoding process on the electrical signal generated by the microphone  313 . Additionally, the instruction bit information may include information specifying a bit rate to be used for the encoding process on the electrical signal generated by the microphone  313 . The instruction bit information is output from the control unit  321  to the encoding unit  322 . The power button  340 B corresponds to the trigger signal generation unit  340  described with reference to  FIG. 4 . 
     After operating the power button  340 B, the user inputs voice instructions for the remote control of a home electric appliance to the microphone  313 . The microphone  313  converts the voice instructions into an electrical signal. The electrical signal is output from the microphone  313  to the I/O section  323 . The I/O section  323  outputs the electrical signal to the encoding unit  322  under control of the control unit  321 . The encoding unit  322  may perform an encoding process on the electrical signal in accordance with the audio encoding scheme specified by the instruction bit information, and generate an instruction stream. Additionally, the encoding unit  322  may perform an encoding process on the electrical signal in accordance with the bit rate specified by the instruction bit information, and generate an instruction stream. The control unit  321  and the encoding unit  322  correspond to the stream generation unit  320 A described with reference to  FIG. 4 . In this embodiment, the first instruction stream is exemplified by the instruction stream generated by the encoding unit  322 . 
     The encoding unit  322  outputs the instruction bit information and the instruction stream to the communication unit  332 . After that, the communication unit  332  transmits the instruction bit information and the instruction stream to the antenna unit  331 . The instruction bit information and the instruction stream are transmitted from the antenna unit  331  to the base unit. The communication unit  332  and the antenna unit  331  correspond to the transmission unit  330  described with reference to  FIG. 4 . 
     When the user inputs the telephone number of an intended party using the input keys  311 , an electrical signal representing the telephone number is output from the input keys  311  to the I/O section  323 . After that, the electrical signal is transferred from the I/O section  323  to the control unit  321 . The control unit  321  generates a control signal for establishing communication between the telephone handset  300 B and the telephone of the intended party in accordance with the electrical signal from the I/O section  323 . After that, the control signal is transmitted from the control unit  321  to the base unit using the antenna unit  331  via the communication unit  332 . A technique for generating a control signal to establish communication between the telephone handset  300 B and the telephone of the intended party may be similar to a generation technique applicable to the telephone handset of a typical cordless telephone device. This embodiment is not limited to a specific technique for generating a control signal. 
     When the control unit  321  receives the electrical signal representing the telephone number, the control unit  321  may generate call bit information. Alternatively, when communication is established between the telephone handset  300 B and the telephone of the intended party (e.g., when the intended party lifts the receiver off the hook), the control unit  321  may generate call bit information. The basic concept of this embodiment is not limited to a specific timing at which call bit information is generated. 
     Similarly to the instruction bit information, the call bit information may include information specifying an audio encoding scheme to be used for the encoding process on the electrical signal generated by the microphone  313 . Additionally, the call bit information may include information specifying a bit rate to be used for the encoding process on the electrical signal generated by the microphone  313 . 
     The user starts a conversation with the intended party after communication has been established between the telephone handset  300 B and the telephone of the intended party. The microphone  313  converts the audio of the user into an electrical signal. The electrical signal is output from the microphone  313  to the I/O section  323 . The I/O section  323  outputs the electrical signal to the encoding unit  322  under control of the control unit  321 . 
     The encoding unit  322  may perform an encoding process on the electrical signal in accordance with the audio encoding scheme specified by the call bit information, and generate a call stream. Additionally, the encoding unit  322  may perform an encoding process on the electrical signal in accordance with the bit rate specified by the call bit information, and generate a call stream. In this embodiment, the first call stream is exemplified by the call stream generated by the encoding unit  322 . 
     The encoding unit  322  outputs the call bit information and the call stream to the communication unit  332 . After that, the communication unit  332  transmits the call bit information and the call stream from the antenna unit  331 . The call bit information and the call stream are transmitted from the antenna unit  331  to the base unit. 
     Embodiment 6 
     The telephone handset described in connection with Embodiment 5 is configured to switch the operation mode between a first operation mode used for making a conversation with an intended party and a second operation mode used for taking remote control of a home electric appliance. The telephone handset transmits a call stream and an instruction stream to the base unit through a common multiplexing scheme. This enables the user to switch the operation mode between the first operation mode and the second operation mode while maintaining the communication between the telephone of the intended party and the telephone handset. In Embodiment 6, a description will be given of the switching of the operation mode between the first operation mode and the second operation mode. 
       FIG. 6  is a schematic timing chart depicting an illustrative operation of the telephone handset  300 B. The operation of the telephone handset  300 B will be described with reference to  FIG. 5  and  FIG. 6 . 
     At time T0, the user operates the power button  340 B to request supply of power from the power supply unit  350 . As a result, power is supplied from the power supply unit  350  to the signal conversion unit  310 B and the integrated circuit  320 B. After that, the user operates the input keys  311  to input the telephone number of the communication partner. As a result, the telephone of the communication partner is called from the telephone handset  300 B. When the communication partner takes the receiver off the hook in response to the call, communication is established between the telephone handset  300 B and the telephone of the communication partner. After that, the telephone handset  300 B operates in the first operation mode. While the telephone handset  300 B is operating in the first operation mode, the user has a conversation with the intended party. In this embodiment, the call mode is exemplified by the first operation mode. 
     At time T1 subsequent to the time T0, the user presses the power button  340 B for a short period of time. As a result, a trigger signal is output from the power button  340 B to the control unit  321 . Accordingly, the control unit  321  receives the trigger signal while the encoding unit  322  is performing a process for generating a call stream. The control unit  321  generates instruction bit information in accordance with the trigger signal. The instruction bit information is output from the control unit  321  to the encoding unit  322 . After that, the encoding unit  322  starts an encoding process for generating an instruction stream. As a result, the operation mode of the telephone handset  300 B is switched from the first operation mode to the second operation mode. 
     While the telephone handset  300 B is operating in the second operation mode, the control unit  321  generates a request signal for requesting that the audio represented by the instruction stream (that is, voice instructions) not be transferred to the telephone of the intended party. The request signal is transmitted from the control unit  321  to the base unit via the communication unit  332  and the antenna unit  331 . The request signal may be transferred from the control unit  321  to the base unit through the multiplexing scheme used for the transmission of the instruction stream and the call stream. As a result of the transmission of the request signal, the telephone handset  300 B can operate in a mute mode for the telephone of the intended party. 
     After the generation of the request signal, the control unit  321  may generate an alternative stream representing an alternative sound that replaces the audio of the user. The alternative stream is transmitted from the control unit  321  to the base unit via the communication unit  332  and the antenna unit  331 . The alternative stream may be transferred from the control unit  321  to the base unit through the multiplexing scheme used for the transmission of the instruction stream and the call stream. 
     At time T2 subsequent to the time T1, the user presses the power button  340 B for a short period of time, and requests to return to the first operation mode. As a result, a new trigger signal is output from the power button  340 B to the control unit  321 . Accordingly, the control unit  321  receives the new trigger signal while the encoding unit  322  is performing a process for generating an instruction stream. The control unit  321  generates call bit information in accordance with the new trigger signal. The second operation mode (mute mode) ends in synchronization with the generation of the call bit information, and the operation mode of the telephone handset  300 B is switched from the second operation mode to the first operation mode. In this embodiment, the second trigger is exemplified by the trigger signal. 
     The call bit information is output from the control unit  321  to the encoding unit  322 . The encoding unit  322  starts an encoding process for generating a call stream in accordance with the call bit information. 
     Embodiment 7 
     Unlike the period of conversation with the intended party, a period required to input voice instructions for remote control of a home electric appliance does not largely vary in length. Accordingly, a fixed period of time may be assigned to the second operation mode. In this case, the designer may design a telephone handset so that the second operation mode is automatically terminated. In Embodiment 7, a description will be given of a telephone handset configured to automatically terminate the second operation mode. 
       FIG. 7  is a schematic block diagram of a telephone handset  300 C according to Embodiment 7. The telephone handset  300 C will be described with reference to  FIG. 6  and  FIG. 7 . Numerals common to Embodiment 5 and Embodiment 7 designate components having substantially the same function as those in Embodiment 5. Thus, these components are identified using the description made in Embodiment 5. 
     Similarly to Embodiment 5, the telephone handset  300 C includes a signal conversion unit  310 B, an antenna unit  331 , a power button  340 B, and a power supply unit  350 . These components are identified using the description made in Embodiment 5. 
     The telephone handset  300 C further includes an integrated circuit  320 C. Similarly to Embodiment 5, the telephone handset  300 C performs processing for a signal to be output to the signal conversion unit  310 B, processing for a signal received from the signal conversion unit  310 B, processing for signals (bit information and stream) output via the antenna unit  331 , and processing for a signal received via the antenna unit  331 . Thus, the description made on the signal processing in connection with Embodiment 5 is used to indicate the integrated circuit  320 C. 
     Similarly to Embodiment 5, the integrated circuit  320 C includes an encoding unit  322 , an I/O section  323 , and a communication unit  332 . These components are identified using the description made in Embodiment 5. 
     The integrated circuit  320 C further includes a control unit  321 C and a timer  324 . The control unit  321 C controls the overall operation of the integrated circuit  320 C. Accordingly, the encoding unit  322 , the I/O section  323 , the timer  324 , and the communication unit  332  operate under control of the control unit  321 C. 
     As described in connection with Embodiment 6, the user operates the power button  340 B at the time T1. As a result, the operation mode of the telephone handset  300 C is switched from the first operation mode to the second operation mode. A predetermined setting period STL is set in the timer  324 . The setting period STL has a length sufficient for the user to give voice instructions to a home electric appliance. 
     The telephone handset  300 C operates in the second operation mode (mute mode) until the setting period STL has elapsed since the time T1. At the time T2 after the setting period STL has elapsed since the time T1, the timer  324  generates a notification signal for sending a notification of the completion of the setting period STL. The notification signal is output from the timer  324  to the control unit  321 C. 
     The control unit  321 C generates call bit information in accordance with the notification signal. The second operation mode (mute mode) ends in synchronization with the generation of the call bit information, and the operation mode of the telephone handset  300 C is switched from the second operation mode to the first operation mode. The call bit information is output from the control unit  321 C to the encoding unit  322 . The encoding unit  322  starts an encoding process for generating a call stream in accordance with the call bit information. 
     Embodiment 8 
     The techniques described in connection with the various embodiments described above may be suitable for use in a control system for controlling a home electric appliance. In Embodiment 8, a description will be given of an illustrative control system. 
       FIG. 8  is a conceptual diagram of a control system  400  according to Embodiment 8. The control system  400  will be described with reference to  FIG. 1 ,  FIG. 4 , and  FIG. 5  to  FIG. 8 . 
     The control system  400  includes a cordless telephone device  101 , a wireless fidelity (WiFi) router  410 , and a cloud server  420 . The cordless telephone device  101  corresponds to the cordless telephone device  100  described with reference to  FIG. 1 . 
     The cordless telephone device  101  includes a base unit  201  and two telephone handsets  301  and  302 . Each of the telephone handsets  301  and  302  may be designed on the basis of the design principles of the telephone handsets  300 B and  300 C described with reference to  FIG. 5  and  FIG. 7 . 
     The call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted from each of the telephone handsets  301  and  302  to the base unit  201  using a TDD-TDMA scheme complying with the DECT standard. The base unit  201  has not only the function of a base unit of a typical cordless telephone device but also the function of a home gateway. Accordingly, the base unit  201  is connected not only to a fixed telephone network FTN (a telephone network used for public fixed telephone services) but also to the WiFi router  410  and a home electric appliance group APG including various home electric appliances. 
     The home electric appliance group APG includes a plurality of home electric appliances to be subject to remote control in accordance with voice instructions of the user. In this embodiment, the home electric appliance group APG includes two lighting devices AP1 and AP2, two air conditioners AP3 and AP4, a television device AP5, a video device AP6, a refrigerator AP7, a microwave oven AP8, and a washing machine AP9. The home electric appliance group APG may include other home electric appliances. The basic concept of this embodiment is not limited by the home electric appliance group APG. 
     The WiFi router  410  is connected to the base unit  201  so that the WiFi router  410  can communicate with the base unit  201  via Ethernet, whereas the WiFi router  410  is connected to the cloud server  420  so that the WiFi router  410  can communicate with the cloud server  420  via the Internet line. While one of the telephone handsets  301  and  302  is operating in the first operation mode (see  FIG. 6 ), the call bit information and the call stream are transmitted from the one of the telephone handsets  301  and  302  to the base unit  201 . The base unit  201  refers to the call bit information, and determines that the call stream is sent to the intended party via the fixed telephone network. When one of the telephone handsets  301  and  302  is operating in the second operation mode (see  FIG. 6 ), the instruction bit information and the instruction stream are transmitted from the one of the telephone handsets  301  and  302  to the base unit  201 . The base unit  201  refers to the instruction bit information, and determines that the instruction stream is sent to the cloud server  420  via the WiFi router  410  and the Internet line. 
     The cloud server  420  includes an authentication unit  421 , a speech recognition unit  422 , an interaction unit  423 , an operation command generation unit  424 , a target device database  425 , and an operation history database  426 . The cloud server  420  stores in advance information concerning the cordless telephone device  101 . When the cloud server  420  receives an instruction stream, the authentication unit  421  determines whether or not the instruction stream is an instruction stream transmitted from an authorized cordless telephone device. This may prevent or at least reduce occurrence of unauthorized remote control of the home electric appliance group APG. 
     After that, the speech recognition unit  422  decodes the instruction stream, and analyzes the voice instructions from the user. The target device database  425  stores in advance information concerning the lighting devices AP1 and AP2, the air conditioners AP3 and AP4, the television device AP5, the video device AP6, the refrigerator AP7, the microwave oven AP8, and the washing machine AP9. The speech recognition unit  422  searches the target device database  425  for a home electric appliance specified by the voice instructions. The speech recognition unit  422  also searches for the content of the operation demanded by the user from the voice instructions. 
     If the voice instructions of the user are not clear, the speech recognition unit  422  may activate the interaction unit  423 . For example, if the speech recognition unit  422  determines “start” as an operation but is not capable of determining a home electric appliance to be started to operate, the speech recognition unit  422  may cause the interaction unit  423  to generate message data representing the message, “Which home electric appliance would you like to start?” The message data is transferred to the telephone handset (one of the telephone handsets  301  and  302 ) that the user is using, via the Internet line, the WiFi router  410 , and the base unit  201 . As a result, a message sound corresponding to “Which home electric appliance would you like to start?” is output from the speaker  312  (see  FIG. 5  or  FIG. 7 ). Then, the user inputs voice instructions to specify a home electric appliance via the microphone  313 , allowing the speech recognition unit  422  to appropriately understand the content of the remote control demanded by the user. 
     The user may operate the telephone handset  301  or  302  to submit a request for interactive input to the cloud server  420 . Also in this case, the speech recognition unit  422  can appropriately understand the voice instructions of the user in cooperation with the interaction unit  423 . 
     The speech recognition unit  422  outputs the result of the speech recognition process described above to the operation command generation unit  424 . The operation command generation unit  424  generates an operation command in accordance with the result of the speech recognition process. 
     The operation command generation unit  424  may refer to the operation history database  426  to generate an operation command. When the user operates a home electric appliance in the home electric appliance group APG, the content of the operation performed on the home electric appliance is delivered from the home electric appliance which has been operated to the cloud server  420  via the base unit  201 , the WiFi router  410 , and the Internet line. Consequently, the content of the operation can be stored in the operation history database  426 . The operation command generated by the operation command generation unit  424  may be output to the operation history database  426 . Consequently, the content of the operation can be stored in the operation history database  426 . 
     In a case where the result of the speech recognition process indicates that “the user wishes to operate the air conditioner AP3 at a set temperature of 28° C.”, the operation command generation unit  424  may refer to the operation history database  426  to determine whether or not the air conditioner AP3 is in operation. If the air conditioner AP3 is in operation, the operation command generation unit  424  generates an operation command for setting the temperature of the air conditioner AP3 to 28° C. If the air conditioner AP3 is not in operation, the operation command generation unit  424  generates an operation command for bringing the air conditioner AP3 into operation, and an operation command for setting the temperature of the air conditioner AP3 to 28° C. 
     The operation command or commands are output from the operation command generation unit  424  to the WiFi router  410 . After that, the operation command or commands are output from the WiFi router  410  to the home electric appliance specified in the voice instructions of the user via the base unit  201 . Upon receipt of the operation command, the home electric appliance executes the operation specified in the voice instructions of the user. 
     Embodiment 9 
     The operation mode of the telephone handset described in connection with Embodiments 5 to 7 may be switched with a simple operation of the telephone handset. This may cause a person having no sufficient knowledge about appropriate remote control of a home electric appliance (e.g., a young child) to operate a home electric appliance by accident. 
     The designer may be able to design a handset connected to the base unit so that the handset and the base unit can communicate with each other, as a wearable terminal on the basis of the principles in the various embodiments described above. In this case, the wearable terminal may be removed from the body of the user. If the user leaves the wearable terminal after removing it from their body, someone may find the wearable terminal and pick it up. If a third party operates the wearable terminal, a home electric appliance may perform an unwanted operation. 
     To address the problem described above, it is desirable that a handset connected to the base unit so that the handset and the base unit can communicate with each other be operated only by an authorized user. In Embodiment 9, a description will be given of a wearable terminal having an authentication function to verify authenticity of a user. 
       FIG. 9  is a schematic block diagram of a wearable terminal  300 D according to Embodiment 9. The wearable terminal  300 D will be described with reference to  FIG. 9 . Numerals common to Embodiment 7 and Embodiment 9 designate components having substantially the same function as those in Embodiment 7. Thus, these components are identified using the description made in Embodiment 7. 
     The designer may design the wearable terminal  300 D so that the wearable terminal  300 D is wearable on a user&#39;s wrist. In this case, the designer may determine the design of the wearable terminal  300 D so that the wearable terminal  300 D looks like a watch or a bangle. The designer may design the wearable terminal  300 D so that the wearable terminal  300 D is wearable on a user&#39;s finger. In this case, the designer may determine the design of the wearable terminal  300 D so that the wearable terminal  300 D looks like a ring. The designer may design the wearable terminal  300 D so that the wearable terminal  300 D can hang from the user&#39;s neck. In this case, the designer may determine the design of the wearable terminal  300 D so that the wearable terminal  300 D looks like a pendant or a necklace. The basic concept of this embodiment is not limited to a specific position at which the wearable terminal  300 D is worn or a specific design of the wearable terminal  300 D. 
     Similarly to Embodiment 7, the wearable terminal  300 D includes an antenna unit  331 , a power button  340 B, and a power supply unit  350 . These components are identified using the description made in Embodiment 7. 
     The wearable terminal  300 D further includes a signal conversion unit  310 D and an integrated circuit  320 D. Similarly to Embodiment 7, the integrated circuit  320 D is responsible for various forms of signal processing such as signal processing for establishing a connection with the telephone of the intended party, signal processing for switching the operation mode between the first operation mode and the second operation mode, and signal processing for generating bit information and streams. The signal processing technique described in connection with Embodiment 7 is applied to the integrated circuit  320 D. 
     The signal conversion unit  310 D converts the signal output from the integrated circuit  320 D into audio or an image. Additionally, the signal conversion unit  310 D converts the operation or audio of the user into an electrical signal. 
     Similarly to Embodiment 7, the signal conversion unit  310 D includes a microphone  313  and a speaker  312 . These components are identified using the description made in Embodiment 7. 
     The speaker  312  and the microphone  313  may be replaced by a device (e.g., a headphone, a Bluetooth (registered trademark) hands-free microphone, or a Bluetooth (registered trademark) headset) different from the wearable terminal  300 D. Thus, the speaker  312  and the microphone  313  may be removed from the signal conversion unit  310 D. 
     The signal conversion unit  310 D further includes a touch panel  311 D and a display  314 . The user may operate the touch panel  311 D to input the telephone number of the intended party. The input telephone number is output to the integrated circuit  320 D as an electrical signal. The integrated circuit  320 D processes the electrical signal representing the telephone number, and transmits a radio wave representing the telephone number from the antenna unit  331  to the base unit. 
     The display  314  displays various images in accordance with signals from the integrated circuit  320 D. When the user operates the touch panel  311 D and inputs the telephone number of the intended party, the integrated circuit  320 D may generate image data representing the input number. The image data is output from the integrated circuit  320 D to the display  314 . The display  314  displays the numbers input to the touch panel  311 D by the user, in accordance with the image data. This enables the user to visually check whether or not the input telephone number is correct. 
     Similarly to Embodiment 7, the integrated circuit  320 D includes an encoding unit  322 , an I/O section  323 , a timer  324 , and a communication unit  332 . These components are identified using the description made in Embodiment 7. 
     The integrated circuit  320 D further includes a control unit  321 D, a storage unit  325 , and an authentication unit  326 . The control unit  321 D executes overall control related to data processing in the integrated circuit  320 D. Accordingly, the I/O section  323 , the timer  324 , the storage unit  325 , the authentication unit  326 , the encoding unit  322 , and the communication unit  332  operate under control of the control unit  321 D. 
     The control unit  321 D may generate image data for requesting the user to enter a password. The image data is output from the control unit  321 D to the display  314  via the I/O section  323 . As a result, the display  314  displays an image for requesting the user to enter a password. 
     In response to the password request image on the display  314 , the user operates the touch panel  311 D and enters a password. Authentication information indicating the entered password is output from the touch panel  311 D to the I/O section  323 . The I/O section  323  outputs the authentication information to the authentication unit  326  under control of the control unit  321 D. 
     The storage unit  325  stores a password preset by the user. Upon receipt of the authentication information, the authentication unit  326  reads the password from the storage unit  325 . After that, the authentication unit  326  compares the authentication information with the read password. 
     If the authentication information matches the read password, the authentication unit  326  notifies the control unit  321 D of successful completion of the authentication. After that, the control unit  321 D may generate image data indicating that the authentication has been successfully completed. The image data is output from the control unit  321 D to the display  314  via the I/O section  323 . As a result, the display  314  displays an image indicating successful completion of the authentication process. 
     If the authentication information does not match the read password, the authentication unit  326  notifies the control unit  321 D that the authentication has failed. After that, the control unit  321 D may generate image data for prompting the user to re-enter a password and/or prompting interruption of authentication. The image data is output from the control unit  321 D to the display  314  via the I/O section  323 . As a result, the display  314  displays an image for prompting the user to re-enter a password and/or prompting interruption of authentication. In response to the displayed image, the user operates the touch panel  311 D and re-enters a password. Alternatively, in response to the displayed image, the user operates the touch panel  311 D and requests the wearable terminal  300 D to interrupt the authentication process. The request for the interruption of the authentication process, which is input via the touch panel  311 D, is output from the touch panel  311 D to the control unit  321 D via the I/O section  323 . Upon receipt of the request for the interruption of the authentication process, the control unit  321 D may cause the I/O section  323  to interrupt the electrical signal from the microphone  313 . This may prevent remote control by a person who does not know the password. 
     In the case of successful completion of the authentication process, the result of the authentication may be held until the wearable terminal  300 D is removed. Alternatively, the authentication process described above may be executed each time the wearable terminal  300 D is operated. Further alternatively, the authentication process described above may be executed at other timing. The basic concept of this embodiment is not limited to specific timing at which the authentication process is executed. 
     Embodiment 10 
     The technique described in connection with Embodiment 9 may be suitable for use in a control system for controlling a home electric appliance. In Embodiment 10, a description will be given of an illustrative control system. 
       FIG. 10  is a conceptual diagram of a control system  401  according to Embodiment 10. The control system  401  will be described with reference to  FIG. 1 ,  FIG. 6 ,  FIG. 9 , and  FIG. 10 . Numerals common to Embodiment 8 and Embodiment 10 designate components having substantially the same function as those in Embodiment 8. Thus, these components are identified using the description made in Embodiment 8. 
     Similarly to Embodiment 8, the control system  401  includes a WiFi router  410  and a cloud server  420 . These components are identified using the description made in Embodiment 8. 
     The control system  401  further includes a cordless telephone device  102 . The cordless telephone device  102  corresponds to the cordless telephone device  100  described with reference to  FIG. 1 . 
     The cordless telephone device  102  includes a base unit  201  and two wearable terminals  303  and  304 . The wearable terminals  303  and  304  may be each designed on the basis of the design principles of the wearable terminal  300 D described with reference to  FIG. 9 . 
     The wearable terminal  303  is wearable on a user&#39;s wrist. The wearable terminal  303  may look like a watch. 
     The wearable terminal  304  is designed to hang from the user&#39;s neck. The wearable terminal  304  may look like a pendant. 
     The call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted from each of the wearable terminals  303  and  304  to the base unit  201  using a TDD-TDMA scheme complying with the DECT standard. When one of the wearable terminals  303  and  304  is operating in the first operation mode (see  FIG. 6 ), the call bit information and the call stream are transmitted from the one of the wearable terminals  303  and  304  to the base unit  201 . The base unit  201  refers to the call bit information, and determines that the call stream is sent to the intended party via a fixed telephone network. When one of the wearable terminals  303  and  304  is operating in the second operation mode (see  FIG. 6 ), the instruction bit information and the instruction stream are transmitted from the one of the wearable terminals  303  and  304  to the base unit  201 . The base unit  201  refers to the instruction bit information, and determines that the instruction stream is sent to the cloud server  420  via the WiFi router  410  and the Internet line. This enables the user to selectively take remote control of the home electric appliance group APG or make a conversation with the intended party by using the wearable terminals  303  and  304 . 
     Embodiment 11 
     A control system may include a smartphone. In Embodiment 11, a description will be given of an illustrative control system including a smartphone. 
       FIG. 11  is a conceptual diagram of a control system  402  according to Embodiment 11. The control system  402  will be described with reference to  FIG. 1  and  FIG. 11 . Numerals common to Embodiment 8, Embodiment 10, and Embodiment 11 designate components having substantially the same function as those in Embodiment 8 and/or Embodiment 10. Thus, these components are identified using the description made in Embodiment 8 and/or Embodiment 10. 
     Similarly to Embodiment 10, the control system  402  includes a WiFi router  410  and a cloud server  420 . These components are identified using the description made in Embodiment 10. 
     The control system  402  further includes a cordless telephone device  103  and a smartphone  430 . The cordless telephone device  103  corresponds to the cordless telephone device  100  described with reference to  FIG. 1 . 
     The cordless telephone device  103  includes a base unit  201 , a telephone handset  301 , and two wearable terminals  303  and  304 . The base unit  201  and the telephone handset  301  are identified using the description made in Embodiment 8. The wearable terminals  303  and  304  are identified using the description made in Embodiment 10. Accordingly, the call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted from each of the telephone handset  301  and the wearable terminals  303  and  304  to the base unit  201  using a TDD-TDMA scheme complying with the DECT standard. 
     The smartphone  430  is connected to the base unit  201  using WiFi communication technology. Additionally, the smartphone  430  is connected to a mobile telephone network MTN. The communication connection between the smartphone  430  and the mobile telephone network MTN may be based on wideband access technology such as long term evolution (LTE) or wideband code division multiple access (W-CDMA). 
     When the smartphone  430  receives an incoming call from the intended party, a notification signal indicating the incoming call to the smartphone  430  is sent to the wearable terminals  303  and  304  via the base unit  201 . The user is able to answer the communication partner using one of the smartphone  430  and the wearable terminals  303  and  304 . If the smartphone  430  is in a user&#39;s bag, the user is also able to answer the intended party using the wearable terminal  303  or  304  without taking the smartphone  430  out of the bag. 
     Embodiment 12 
     It will be convenient for a user who is familiar with a smartphone if a control system permits the user to operate the smartphone to control a home electric appliance. In Embodiment 12, a description will be given of an illustrative control system that permits a user to operate a smartphone to control a home electric appliance. 
       FIG. 12  is a conceptual diagram of a control system  402 E according to Embodiment 12. The control system  402 E will be described with reference to  FIG. 1  and  FIG. 12 . Numerals common to Embodiment 11 and Embodiment 12 designate components having substantially the same function as those in Embodiment 11. Thus, these components are identified using the description made in Embodiment 11. 
     Similarly to Embodiment 11, the control system  402 E includes a cordless telephone device  103 , a WiFi router  410 , and a cloud server  420 . These components are identified using the description made in Embodiment 11. 
     The control system  402 E further includes a smartphone  430 E. The smartphone  430 E is connected to the cloud server  420 . The communication connection between the smartphone  430 E and the cloud server  420  may be based on wideband access technology such as the third generation (3G) or LTE. 
     An application program for remote control of the home electric appliance group APG has been downloaded to the smartphone  430 E. A user gives voice instructions to the smartphone  430 E. The smartphone  430 E generates a radio wave representing the voice instructions. The radio wave is transferred from the smartphone  430 E to the cloud server  420 . 
     After that, the cloud server  420  generates an operation command on the basis of the technique described in connection with Embodiment 8. The operation command is finally transferred to the home electric appliance specified in the voice instructions. This enables the user to take appropriate remote control of a home electric appliance using the smartphone  430 E. 
     Embodiment 13 
     A wearable terminal is available in various communication environments. In Embodiment 13, a description will be given of a wearable terminal available in various communication environments. Note that a technique described in connection with Embodiment 13 may be applied to a telephone handset. 
       FIG. 13  is a schematic block diagram of a wearable terminal  300 F according to Embodiment 13. The wearable terminal  300 F will be described with reference to  FIG. 1 ,  FIG. 9 , and  FIG. 13 . Numerals common to Embodiment 9 and Embodiment 13 designate components having substantially the same function as those in Embodiment 9. Thus, these components are identified using the description made in Embodiment 9. 
     The designer may design the wearable terminal  300 F so that the wearable terminal  300 F is wearable on a user&#39;s wrist. In this case, the designer may determine the design of the wearable terminal  300 F so that the wearable terminal  300 F looks like a watch or a bangle. The designer may design the wearable terminal  300 F so that the wearable terminal  300 F is wearable on a user&#39;s finger. In this case, the designer may determine the design of the wearable terminal  300 F so that the wearable terminal  300 F looks like a ring. The designer may design the wearable terminal  300 F so that the wearable terminal  300 F can hang from the user&#39;s neck. In this case, the designer may determine the design of the wearable terminal  300 F so that the wearable terminal  300 F looks like a pendant or a necklace. The basic concept of this embodiment is not limited to a specific position at which the wearable terminal  300 F is worn or a specific design of the wearable terminal  300 F. 
     Similarly to Embodiment 9, the wearable terminal  300 F includes a signal conversion unit  310 D, an antenna unit  331 , a power button  340 B, and a power supply unit  350 . These components are identified using the description made in Embodiment 9. 
     The wearable terminal  300 F further includes an integrated circuit  320 F. Similarly to Embodiment 9, the integrated circuit  320 F is responsible for various forms of signal processing such as signal processing for establishing a connection with the telephone of the intended party, signal processing for switching the operation mode between the first operation mode and the second operation mode, signal processing for generating bit information and streams, and processing for user authentication. The signal processing technique described in connection with Embodiment 9 is applicable to the integrated circuit  320 F. 
     Similarly to Embodiment 9, the integrated circuit  320 F includes an encoding unit  322 , an I/O section  323 , a timer  324 , a storage unit  325 , and an authentication unit  326 . These components are identified using the description made in Embodiment 9. 
     The integrated circuit  320 F further includes a control unit  321 F and a communication unit  332 F. The control unit  321 F executes overall control related to data processing in the integrated circuit  320 F. Accordingly, the I/O section  323 , the timer  324 , the storage unit  325 , the authentication unit  326 , the encoding unit  322 , and the communication unit  332 F operate under control of the control unit  321 F. 
     The communication unit  332 F transmits the instruction bit information, the instruction stream, the call bit information, and the call stream from the antenna unit  331  under control of the control unit  321 F. Accordingly, the communication unit  332 F and the antenna unit  331  correspond to the transmission unit  330  described with reference to  FIG. 1 . 
     The communication unit  332 F includes a first communication unit  333  and a second communication unit  334 . The control unit  321 F selects one of the first communication unit  333  and the second communication unit  334  as a communication element used for the transmission of the instruction bit information, the instruction stream, the call bit information, and the call stream. 
     When the control unit  321 F designates the first communication unit  333 , the instruction bit information, the instruction stream, the call bit information, and the call stream are transmitted to the base unit through a TDD-TDMA scheme complying with the DECT standard. Accordingly, the first communication unit  333  corresponds to the communication unit  332  described with reference to  FIG. 9 . 
     When the control unit  321 F designates the second communication unit  334 , the instruction bit information, the instruction stream, the call bit information, and the call stream are transmitted in accordance with short-range radio technology such as Bluetooth (registered trademark). 
     The user may operate the touch panel  311 D to request the integrated circuit  320 F to display an image for selecting a communication scheme. In response to the request from the user, the control unit  321 F generates image data representing an image for selecting a communication scheme. The image data is output from the control unit  321 F to the display  314  via the I/O section  323 . As a result, the display  314  displays an image for selecting a communication scheme. 
     The user operates the touch panel  311 D to select one of the first communication unit  333  and the second communication unit  334 . The touch panel  311 D generates a selection signal representing the selection of the user. The selection signal is output from the touch panel  311 D to the control unit  321 F via the I/O section  323 . The control unit  321 F designates one of the first communication unit  333  and the second communication unit  334  in accordance with the selection signal. 
     The control unit  321 F may refer to the radio wave received by the antenna unit  331  and determine the communication environment of the wearable terminal  300 F. In this case, the control unit  321 F may select one of the first communication unit  333  and the second communication unit  334  in terms of the communication environment. The basic concept of this embodiment is not limited to a specific method for selecting one of the first communication unit  333  and the second communication unit  334 . 
     Embodiment 14 
     The technique described in connection with Embodiment 13 may be suitable for use in a control system for controlling a home electric appliance. In Embodiment 14, a description will be given of an illustrative control system. 
       FIG. 14  is a conceptual diagram of a control system  400 F according to Embodiment 14. The control system  400 F will be described with reference to  FIG. 1 ,  FIG. 13 , and  FIG. 14 . Numerals common to Embodiment 8 and Embodiment 14 designate components having substantially the same function as those in Embodiment 8. Thus, these components are identified using the description made in Embodiment 8. 
     Similarly to Embodiment 8, the control system  400 F includes a WiFi router  410  and a cloud server  420 . These components are identified using the description made in Embodiment 8. 
     The control system  400 F further includes a cordless telephone device  102 F. The cordless telephone device  102 F corresponds to the cordless telephone device  100  described with reference to  FIG. 1 . 
     The cordless telephone device  102 F includes a base unit  201 , a telephone handset  301 , and a wearable terminal  300 F. The base unit  201  and the telephone handset  301  are identified using the description made in Embodiment 8. 
       FIG. 14  illustrates a use environment of the wearable terminal  300 F inside the user&#39;s home. As described in connection with Embodiment 13, the user operates the touch panel  311 D to specify the first communication unit  333 . As a result, the call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted from the wearable terminal  300 F to the base unit  201  using the TDD-TDMA scheme complying with the DECT standard. 
       FIG. 15  is a conceptual diagram illustrating a use environment of the wearable terminal  300 F outside the user&#39;s home. A technique for switching between communication technologies will be described with reference to  FIG. 13  to  FIG. 15 . 
     A user is away from home while carrying a smartphone SMP. An application program for relaying an instruction stream between the wearable terminal  300 F and the cloud server  420  has been downloaded to the smartphone SMP. The smartphone SMP is connected to the cloud server  420  via wideband access such as 3G or LTE. 
     Since the user is wearing the wearable terminal  300 F, the distance from the wearable terminal  300 F to the smartphone SMP is sufficiently short to perform Bluetooth (registered trademark) communication between the wearable terminal  300 F and the smartphone SMP. As described in connection with Embodiment 13, the user operates the touch panel  311 D to specify the second communication unit  334 . As a result, the call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted to the smartphone SMP under Bluetooth (registered trademark) communication technology. The smartphone SMP is capable of delivering the instruction stream to the cloud server  420  via the wideband access described above. 
     The user may also specify the second communication unit  334  while they are at home. However, when the user wishes to perform long-range communication, it is more preferable that the first communication unit  333  be selected than the second communication unit  334  would be. 
     Embodiment 15 
     A wearable terminal is available in various communication environments. In Embodiment 15, a description will be given of a wearable terminal available in various communication environments. Note that a technique described in connection with Embodiment 15 may be applied to a telephone handset. 
       FIG. 16  is a schematic block diagram of a wearable terminal  300 G according to Embodiment 15. The wearable terminal  300 G will be described with reference to  FIG. 1  and  FIG. 16 . Numerals common to Embodiment 13 and Embodiment 15 designate components having substantially the same function as those in Embodiment 13. Thus, these components are identified using the description made in Embodiment 13. 
     The designer may design the wearable terminal  300 G so that the wearable terminal  300 G is wearable on a user&#39;s wrist. In this case, the designer may determine the design of the wearable terminal  300 G so that the wearable terminal  300 G looks like a watch or a bangle. The designer may design the wearable terminal  300 G so that the wearable terminal  300 G is wearable on a user&#39;s finger. In this case, the designer may determine the design of the wearable terminal  300 G so that the wearable terminal  300 G looks like a ring. The designer may design the wearable terminal  300 G so that the wearable terminal  300 G can hang from the user&#39;s neck. In this case, the designer may determine the design of the wearable terminal  300 G so that the wearable terminal  300 G looks like a pendant or a necklace. The basic concept of this embodiment is not limited to a specific position at which the wearable terminal  300 G is worn or a specific design of the wearable terminal  300 G. 
     Similarly to Embodiment 13, the wearable terminal  300 G includes a signal conversion unit  310 D, an antenna unit  331 , a power button  340 B, and a power supply unit  350 . These components are identified using the description made in Embodiment 13. 
     The wearable terminal  300 G further includes an integrated circuit  320 G. Similarly to Embodiment 13, the integrated circuit  320 G is responsible for various forms of signal processing such as signal processing for establishing a connection with the telephone of the intended party, signal processing for switching the operation mode between the first operation mode and the second operation mode, and signal processing for generating bit information and streams, and processing for user authentication. The signal processing technique described in connection with Embodiment 13 is applicable to the integrated circuit  320 G. 
     Similarly to Embodiment 13, the integrated circuit  320 G includes an encoding unit  322 , an I/O section  323 , a timer  324 , a storage unit  325 , and an authentication unit  326 . These components are identified using the description made in Embodiment 13. 
     The integrated circuit  320 G further includes a control unit  321 G and a communication unit  332 G. The control unit  321 G executes overall control related to data processing in the integrated circuit  320 G. Accordingly, the I/O section  323 , the timer  324 , the storage unit  325 , the authentication unit  326 , the encoding unit  322 , and the communication unit  332 G operate under control of the control unit  321 G. 
     The communication unit  332 G transmits the instruction bit information, the instruction stream, the call bit information, and the call stream from the antenna unit  331  under control of the control unit  321 G. Accordingly, the communication unit  332 G and the antenna unit  331  correspond to the transmission unit  330  described with reference to  FIG. 1 . 
     Similarly to Embodiment 13, the communication unit  332 G includes a first communication unit  333  and a second communication unit  334 . These components are identified using the description made in Embodiment 13. 
     The communication unit  332 G further includes a third communication unit  335 . The control unit  321 G selects one of the first communication unit  333 , the second communication unit  334 , and the third communication unit  335  as a communication element used for the transmission of the instruction bit information, the instruction stream, the call bit information, and the call stream. 
     When the control unit  321 G designates the first communication unit  333 , the instruction bit information, the instruction stream, the call bit information, and the call stream are transmitted to the base unit through a TDD-TDMA scheme complying with the DECT standard. 
     When the control unit  321 G designates the second communication unit  334 , the instruction bit information, the instruction stream, the call bit information, and the call stream are transmitted in accordance with short-range radio technology such as Bluetooth (registered trademark). 
     When the control unit  321 G designates the third communication unit  335 , the instruction bit information, the instruction stream, the call bit information, and the call stream are transmitted on the basis of long-range radio technology such as 3G. 
     The user may operate the touch panel  311 D to request the integrated circuit  320 G to display an image for selecting a communication scheme. In response to the request from the user, the control unit  321 G generates image data representing an image for displaying a communication scheme. The image data is output from the control unit  321 G to the display  314  via the I/O section  323 . As a result, the display  314  displays an image for selecting a communication scheme. 
     The user operates the touch panel  311 D to select one of the first communication unit  333 , the second communication unit  334 , and the third communication unit  335 . The touch panel  311 D generates a selection signal representing the selection of the user. The selection signal is output from the touch panel  311 D to the control unit  321 G via the I/O section  323 . The control unit  321 G designates one of the first communication unit  333 , the second communication unit  334 , and the third communication unit  335  in accordance with the selection signal. 
     The control unit  321 G may refer to the radio wave received by the antenna unit  331  and determine the communication environment of the wearable terminal  300 G. In this case, the control unit  321 G may select one of the first communication unit  333 , the second communication unit  334 , and the third communication unit  335  in terms of the communication environment. The basic concept of this embodiment is not limited to a specific method for selecting one of the first communication unit  333 , the second communication unit  334 , and the third communication unit  335 . 
     Embodiment 16 
     The technique described in connection with Embodiment 15 may be suitable for use in a control system for controlling a home electric appliance. In Embodiment 16, a description will be given of an illustrative control system. 
       FIG. 17  is a conceptual diagram of a control system  400 G according to Embodiment 16. The control system  400 G will be described with reference to  FIG. 1 ,  FIG. 16 , and  FIG. 17 . Numerals common to Embodiment 14 and Embodiment 16 designate components having substantially the same function as those in Embodiment 14. Thus, these components are identified using the description made in Embodiment 14. 
     Similarly to Embodiment 14, the control system  400 G includes a WiFi router  410  and a cloud server  420 . These components are identified using the description made in Embodiment 14. 
     The control system  400 G further includes a cordless telephone device  102 G. The cordless telephone device  102 G corresponds to the cordless telephone device  100  described with reference to  FIG. 1 . 
     The cordless telephone device  102 G includes a base unit  201 , a telephone handset  301 , and a wearable terminal  300 G. The base unit  201  and the telephone handset  301  are identified using the description made in Embodiment 14. 
       FIG. 17  illustrates a use environment of the wearable terminal  300 G inside the user&#39;s home. As described in connection with Embodiment 15, the user operates the touch panel  311 D to specify the first communication unit  333 . As a result, the call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted from the wearable terminal  300 G to the base unit  201  using the TDD-TDMA scheme complying with the DECT standard. 
       FIG. 18A  and  FIG. 18B  are conceptual diagrams illustrating a use environment of the wearable terminal  300 G outside the user&#39;s home. Switching between communication technologies will be described with reference to  FIG. 16  to  FIG. 18A . 
     In the use environment illustrated in  FIG. 18A , a user is away from home while carrying a smartphone SMP. Since the user is wearing the wearable terminal  300 G, the distance from the wearable terminal  300 G to the smartphone SMP is sufficiently short to perform Bluetooth (registered trademark) communication between the wearable terminal  300 G and the smartphone SMP. As described in connection with Embodiment 15, the user operates the touch panel  311 D to specify the second communication unit  334 . As a result, the call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted to the smartphone SMP under Bluetooth (registered trademark) communication technology. The smartphone SMP is capable of delivering the instruction stream to the cloud server  420  via the wideband access described previously. 
     In the use environment illustrated in  FIG. 18B , the user is away from home without carrying the smartphone SMP. In this case, the user operates the touch panel  311 D to specify the third communication unit  335 . As a result, the call bit information, the call stream, the instruction bit information, and the instruction stream are transmitted to the cloud server  420  using 3G communication technology. 
     Embodiment 17 
     A base unit of a cordless telephone device may forward a stream received from a handset to a server or an intended party as it is. Alternatively, the base unit may decode a stream received by the handset and re-encode the stream. In Embodiment 17, a description will be given of a cordless telephone device including a base unit that decodes a stream received from a handset and re-encodes the stream. 
       FIG. 19  is a schematic block diagram of a cordless telephone device  100 H according to Embodiment 17. The cordless telephone device  100 H will be described with reference to  FIG. 19 . Numerals common to Embodiment 1 and Embodiment 17 designate components having substantially the same function as those in Embodiment 1. Thus, these components are identified using the description made in Embodiment 1. 
     Similarly to Embodiment 1, the cordless telephone device  100 H includes a handset  300 . The handset  300  is identified using the description made in Embodiment 1. 
     The cordless telephone device  100 H further includes a base unit  200 H. The base unit  200 H includes a generation unit  210  and a transmission unit  220 . The instruction bit information, the instruction stream, the call bit information, and the call stream, which are generated by the handset  300 , are transferred to the generation unit  210  as encoded signals. 
     When the generation unit  210  receives an encoded signal from the handset  300 , the generation unit  210  decodes the signal. After that, the generation unit  210  determines whether the signal includes the instruction bit information or includes the call bit information. If the signal includes the instruction bit information, the generation unit  210  re-encodes the instruction stream. If the signal includes the call bit information, the generation unit  210  re-encodes the call stream. In this embodiment, the second generation unit is exemplified by the generation unit  210 . The second instruction stream is exemplified by the instruction stream re-encoded by the generation unit  210 . The second call stream is exemplified by the call stream re-encoded by the generation unit  210 . 
     The re-encoded instruction stream is output from the generation unit  210  to the transmission unit  220 . The transmission unit  220  transmits the instruction stream to the server SVR. The server SVR generates an operation command for controlling the home electric appliance APL, in accordance with receipt of the instruction stream. In this embodiment, the control command is exemplified by the operation command generated by the server SVR. 
     The re-encoded call stream is output from the generation unit  210  to the transmission unit  220 . The transmission unit  220  transmits the call stream to the telephone of the intended party ITP. In this embodiment, the second transmission unit is exemplified by the transmission unit  220 . 
     Embodiment 18 
     The base unit of the cordless telephone device described in connection with Embodiment 17 is configured to operate under various forms of control. In Embodiment 18, a description will be given of an illustrative control method for the base unit. 
       FIG. 20  is a schematic flowchart of an illustrative control method for the base unit  200 H. A control method for the base unit  200 H will be described with reference to  FIG. 19  and  FIG. 20 . 
     Step S 310   
     In step S 310 , an encoded signal is transferred to the generation unit  210 . Then, step S 320  is executed. 
     Step S 320   
     In step S 320 , the generation unit  210  decodes the encoded signal. Then, step S 330  is executed. 
     Step S 330   
     In step S 330 , the generation unit  210  determines whether or not the decoded signal includes the call bit information. If the decoded signal includes the call bit information, step S 340  is executed. Otherwise, step S 360  is executed. 
     Step S 340   
     In step S 340 , the generation unit  210  re-encodes the call stream. The re-encoded call stream is output from the generation unit  210  to the transmission unit  220 . Then, step S 350  is executed. In this embodiment, the second generation step is exemplified by step S 340 . 
     Step S 350   
     In step S 350 , the transmission unit  220  transmits the call stream to the telephone of the intended party ITP. In this embodiment, the second transmission step is exemplified by step S 350 . 
     Step S 360   
     In step S 360 , the generation unit  210  re-encodes the instruction stream. The re-encoded instruction stream is output from the generation unit  210  to the transmission unit  220 . Then, step S 370  is executed. In this embodiment, the second generation step is exemplified by step S 360 . 
     Step S 370   
     In step S 370 , the transmission unit  220  transmits the instruction stream to the server SVR. In this embodiment, the second transmission step is exemplified by step S 370 . 
     Embodiment 19 
     The control system described in connection with the various embodiments described above includes a base unit configured to function as a home gateway. In Embodiment 19, a description will be given of a base unit configured to function as a home gateway. 
       FIG. 21  is a schematic block diagram of a base unit  201 I according to Embodiment 19. The base unit  201 I will be described with reference to  FIG. 8  and  FIG. 19  to  FIG. 21 . 
     The base unit  201 I functions not only as a telephone but also as a home gateway. The base unit  201 I may be used as the base unit  201  described with reference to  FIG. 8 . Accordingly, the base unit  201 I is connected not only to the fixed telephone network FTN but also to the WiFi router  410 . 
     The base unit  201 I is configured to deliver the audio of the user to the intended party via the fixed telephone network FTN. The base unit  201 I is configured to deliver the audio of the intended party to the user via the fixed telephone network FTN. 
     The base unit  201 I is configured to deliver voice instructions for requesting remote control of the home electric appliance group APG to the cloud server  420  via the WiFi router  410 . The base unit  201 I is configured to receive an operation command generated by the cloud server  420  via the WiFi router  410 . The operation command is transferred from the base unit  201 I to the home electric appliance group APG via Ethernet. The home electric appliance group APG executes the operation corresponding to the voice instructions in accordance with the operation command. This enables the user to take appropriate remote control of the home electric appliance group APG. 
     The base unit  201 I includes a power supply unit  290 , an audio processing unit  240 , an interface unit  250 , an integrated circuit  260 , and an antenna unit  270 . The power supply unit  290  supplies power to the audio processing unit  240 , the interface unit  250 , and the integrated circuit  260 . The audio processing unit  240  converts the audio of the user into an electrical signal, and also converts a signal received from the integrated circuit  260  into audio. The interface unit  250  receives an operation of the user, and provides the user with necessary information. The integrated circuit  260  performs various forms of signal processing. The antenna unit  270  receives encoded signals from the telephone handsets  301  and  302 . 
     The audio processing unit  240  includes a speaker  241  and a microphone  242 . An audio signal transmitted from the telephone of the intended party is subject to predetermined processing by the integrated circuit  260 . After that, the audio signal is output from the integrated circuit  260  to the speaker  241 . The speaker  241  converts the audio signal into audio. This enables the user to hear the audio of the intended party. The user provides audio to the microphone  242 . The microphone  242  converts the audio into an electrical signal. The electrical signal is output from the microphone  242  to the integrated circuit  260 . The integrated circuit  260  processes the electrical signal. After that, the electrical signal is output from the integrated circuit  260  to the fixed telephone network FTN or the WiFi router  410 . 
     The interface unit  250  includes input keys  251  and a display  252 . The input keys  251  may be number keys (or a ten-key pad) of a typical telephone. The user may operate the input keys  251  to input the telephone number of the intended party. The input telephone number is output to the integrated circuit  260  as an electrical signal. The integrated circuit  260  processes the electrical signal representing the telephone number, and establishes communication between the base unit  201 I and the telephone of the intended party via the fixed telephone network FTN. The integrated circuit  260  may generate image data representing the numbers input by the user, in accordance with receipt of the electrical signal representing the telephone number. The image data is output from the integrated circuit  260  to the display  252 . The display  252  displays an image representing the numbers input by the user. This enables the user to visually check whether or not the input numbers are correct. 
     The integrated circuit  260  includes a determination unit  211 , an encoding unit  212 , a communication management unit  220 I, and an I/O section  230 . The determination unit  211  decodes the encoded signal received by the antenna unit  270  (step S 320  described with reference to  FIG. 20 ). The determination unit  211  then determines whether the signal includes the call bit information or includes the instruction bit information (step S 330  described with reference to  FIG. 20 ). 
     If the signal includes the call bit information, the call bit information and the call stream are output from the determination unit  211  to the encoding unit  212 . The encoding unit  212  encodes the call stream (step S 340  described with reference to  FIG. 20 ). The encoding unit  212  specifies an output path of the encoded call stream, and outputs the encoded call stream to the communication management unit  220 I. After that, the communication management unit  220 I outputs the encoded call stream to the fixed telephone network FTN (step S 350  described with reference to  FIG. 20 ). 
     If the signal includes the instruction bit information, the instruction bit information and the instruction stream are output from the determination unit  211  to the encoding unit  212 . The encoding unit  212  encodes the instruction stream (step S 360  described with reference to  FIG. 20 ). The encoding unit  212  specifies an output path of the encoded instruction stream, and outputs the encoded instruction stream to the communication management unit  220 I. After that, the communication management unit  220 I outputs the encoded instruction stream to the WiFi router  410  (step S 370  described with reference to  FIG. 20 ). The determination unit  211  and the encoding unit  212  correspond to the generation unit  210  described with reference to  FIG. 19 . The communication management unit  220 I corresponds to the transmission unit  220  described with reference to  FIG. 19 . 
     The audio provided by the user to the microphone  242  is input to the I/O section  230  as an electrical signal. After that, the electrical signal representing the audio is output from the I/O section  230  to the encoding unit  212 . The encoding unit  212  encodes the electrical signal. The encoding unit  212  specifies an output path of the encoded electrical signal, and outputs the encoded electrical signal to the communication management unit  220 I. After that, the communication management unit  220 I outputs the encoded electrical signal to the fixed telephone network FTN. 
     The communication management unit  220 I includes a first communication management unit  221 , a second communication management unit  222 , and a third communication management unit  223 . The first communication management unit  221  manages communication made through the fixed telephone network FTN. The second communication management unit  222  manages communication made through a multiplexing scheme (e.g., a TDD-TDMA scheme complying with the DECT standard) constructed between the telephone handsets  301  and  302  and the base unit  201 I. The third communication management unit  223  manages communication made through the WiFi router  410  and Ethernet. 
     When the telephone of the intended party sends an audio signal to the base unit  201 i via the fixed telephone network FTN, the first communication management unit  221  receives the audio signal. When the user answers the communication partner using the audio processing unit  240 , the audio signal is output from the first communication management unit  221  to the speaker  241  via the I/O section  230 . When the user answers the intended party using one of the telephone handsets  301  and  302 , the first communication management unit  221  transmits the audio signal generated by the intended party from the antenna unit  270  to the one of the telephone handsets  301  and  302  in cooperation with the second communication management unit  222 . 
     When the user provides audio to the microphone  242  and when the antenna unit  270  receives the call bit information, the encoding unit  212  outputs the encoded signal to the first communication management unit  221 . The first communication management unit  221  transmits the encoded signal to the telephone of the intended party via the fixed telephone network FTN. In this embodiment, the second public communication line is exemplified by the fixed telephone network used for communication between the first communication management unit  221  and the telephone of the intended party. 
     When the antenna unit  270  receives an encoded signal from one of the telephone handsets  301  and  302 , the encoded signal is output from the second communication management unit  222  to the determination unit  211 . The encoded signal is decoded by the determination unit  211 . If the decoded signal includes the instruction bit information, the encoding unit  212  outputs the instruction stream to the third communication management unit  223  after performing an encoding process. 
     The third communication management unit  223  includes a cloud communication unit  229  and a home appliance communication unit  228 . When the third communication management unit  223  receives the instruction stream, the instruction stream is transmitted from the cloud communication unit  229  to the cloud server  420  via the WiFi router  410 . In this embodiment, the first public communication line is exemplified by the Internet line constructed between the WiFi router  410  and the cloud server  420 . 
     The cloud server  420  generates an operation command in accordance with the instruction stream. The operation command is output from the cloud server  420  to the third communication management unit  223  via the WiFi router  410 . When the third communication management unit  223  receives the operation command, the home appliance communication unit  228  outputs the operation command to the home electric appliance group APG via Ethernet. As a result, a home electric appliance in the home electric appliance group APG operates in accordance with the operation command. 
     Embodiment 20 
     The base unit described in connection with Embodiment 19 is configured to operate under various forms of control. In Embodiment 20, a description will be given of an illustrative control method for the base unit. 
       FIG. 22  is a schematic flowchart of an illustrative control method for the base unit  201 I. A control method for the base unit  201 I will be described with reference to  FIG. 8 ,  FIG. 21 , and  FIG. 22 . 
     Step S 410   
     Step S 410  is executed until an encoded signal is transmitted to the antenna unit  270 . When an encoded signal is transmitted to the antenna unit  270 , step S 420  is executed. 
     Step S 420   
     In step S 420 , the second communication management unit  222  outputs the encoded signal to the determination unit  211 . The determination unit  211  decodes the encoded signal. The determination unit  211  determines whether or not the decoded signal includes the call bit information. If the decoded signal includes the call bit information, step S 430  is executed. Otherwise, step S 450  is executed. 
     Step S 430   
     In step S 430 , the call bit information and the call stream are output from the determination unit  211  to the encoding unit  212 . The encoding unit  212  encodes the call stream. The encoded call stream is output from the encoding unit  212  to the first communication management unit  221 . After that, the encoded call stream is output from the first communication management unit  221  to the telephone of the intended party via the fixed telephone network FTN. Then, step S 440  is executed. 
     Step S 440   
     In step S 440 , the first communication management unit  221  determines whether or not the communication connection with the telephone of the communication partner is ongoing. If the communication connection with the telephone of the communication partner is ongoing, step S 410  is executed. Otherwise, the process ends. 
     Step S 450   
     The determination unit  211  determines whether or not the decoded signal includes the instruction bit information. If the decoded signal includes the instruction bit information, step S 460  is executed. Otherwise, step S 470  is executed. 
     Step S 460   
     In step S 460 , the instruction bit information and the instruction stream are output from the determination unit  211  to the encoding unit  212 . The encoding unit  212  encodes the instruction stream. The encoded instruction stream is output from the encoding unit  212  to the third communication management unit  223 . After that, the encoded instruction stream is output to the cloud server  420  via the WiFi router  410  by the cloud communication unit  229 . Then, step S 440  is executed. 
     Step S 470   
     In step S 470 , the determination unit  211  generates a NACK signal. The NACK signal is output from the determination unit  211  to the second communication management unit  222 . The NACK signal is transmitted from the second communication management unit  222  to one of the telephone handsets  301  and  302 . 
     Embodiment 21 
     In Embodiment 6, the operation mode is switched to the mute mode by using the handset. Alternatively, the base unit may switch the operation mode to the mute mode. In Embodiment 21, a description will be given of switching to the mute mode by using the base unit. 
       FIG. 23  is a schematic flowchart of control of switching to the mute mode, which is executed by using the base unit  201 I. A control method for the base unit  201 I will be described with reference to  FIG. 8 ,  FIG. 21 , and  FIG. 23 . 
     Step S 510   
     In step S 510 , the call bit information and the call stream are transmitted from one of the telephone handsets  301  and  302  to the antenna unit  270 . Then, step S 520  is executed. 
     Step S 520   
     In step S 520 , in response to a request from the user, by operating one of the telephone handsets  301  and  302 , to switch the operation mode to the mute mode, the one of the telephone handsets  301  and  302  generates a first switching signal. The first switching signal is transmitted from the one of the telephone handsets  301  and  302  to the antenna unit  270 . When the antenna unit  270  receives the first switching signal, step S 530  and step S 550  are performed in parallel. Otherwise, step S 590  is executed. 
     Step S 530   
     In step S 530 , the instruction bit information and the instruction stream are transmitted from the one of the telephone handsets  301  and  302  to the antenna unit  270 . Then, step S 540  is executed. 
     Step S 540   
     In step S 540 , the instruction bit information and the instruction stream are output from the second communication management unit  222  to the determination unit  211 . Then, step S 570  is executed. 
     Step S 550   
     In step S 550 , the first communication management unit  221  generates an alternative sound signal representing an alternative sound (e.g., noise or background sound). Then, step S 560  is executed. 
     Step S 560   
     In step S 560 , the alternative sound signal is transmitted from the first communication management unit  221  to the telephone of the intended party via the fixed telephone network FTN. Then, step S 570  is executed. 
     Step S 570   
     In step S 570 , in response to a request from the user, by operating one of the telephone handsets  301  and  302 , to exit the mute mode, the one of the telephone handsets  301  and  302  generates a second switching signal. The second switching signal is transmitted from the one of the telephone handsets  301  and  302  to the antenna unit  270 . When the antenna unit  270  receives the second switching signal, step S 510  is executed. Otherwise, step S 580  is executed. 
     Step S 580   
     In step S 580 , the first communication management unit  221  determines whether or not the communication connection with the telephone of the communication partner is ongoing. If the communication connection with the telephone of the communication partner is ongoing, step S 530  and step S 550  are performed in parallel. Otherwise, the process ends. 
     Step S 590   
     In step S 590 , the first communication management unit  221  determines whether or not the communication connection with the telephone of the communication partner is ongoing. If the communication connection with the telephone of the communication partner is ongoing, step S 510  is executed. Otherwise, the process ends. 
     Embodiment 22 
     The base unit according to Embodiment 19 communicates with a cloud server via a WiFi router, and also communicates with a home electric appliance via Ethernet. Alternatively, similarly to communication with the cloud server, the base unit may communicate with a home electric appliance via the WiFi router. In Embodiment 22, a description will be given of a base unit that communicates not only with a cloud server but also with a home electric appliance via a WiFi router. 
       FIG. 24  is a schematic block diagram of a base unit  201 J according to Embodiment 22. The base unit  201 J will be described with reference to  FIG. 24 . Numerals common to Embodiment 19 and Embodiment 22 designate components having substantially the same function as those in Embodiment 19. Thus, these components are identified using the description made in Embodiment 19. 
     Similarly to Embodiment 19, the base unit  201 J includes a power supply unit  290 , an audio processing unit  240 , and an interface unit  250 . These components are identified using the description made in Embodiment 19. 
     The base unit  201 J further includes an integrated circuit  260 J and an antenna unit  270 J. The antenna unit  270 J receives signals from various handsets (e.g., a telephone handset and a wearable terminal) connected to the base unit  201 J so that the handsets and the base unit  201 J can communicate with each other, using a multiplexing scheme. The integrated circuit  260 J processes the signals received by the antenna unit  270 J. 
     Similarly to Embodiment 19, the integrated circuit  260 J includes a determination unit  211 , an encoding unit  212 , and an I/O section  230 . These components are identified using the description made in Embodiment 19. 
     The integrated circuit  260 J further includes a communication management unit  220 J. The communication management unit  220 J manages communication with the fixed telephone network FTN and the WiFi router  410 . 
     Similarly to Embodiment 19, the communication management unit  220 J includes a first communication management unit  221  and a second communication management unit  222 . These components are identified using the description made in Embodiment 19. 
     The communication management unit  220 J further includes a third communication management unit  223 J. Unlike Embodiment 19, the third communication management unit  223 J is dedicated to the management of communication made through the WiFi router  410 . 
     The antenna unit  270 J receives a signal from the WiFi router  410 . Additionally, the antenna unit  270 J transmits a signal to the WiFi router  410 . 
     Similarly to Embodiment 19, the antenna unit  270 J is connected to the second communication management unit  222 . Unlike Embodiment 19, the antenna unit  270 J is also connected to the third communication management unit  223 J. 
     Similarly to Embodiment 19, the third communication management unit  223 J includes a cloud communication unit  229 . The cloud communication unit  229  transmits the encoded instruction stream from the antenna unit  270 J to the WiFi router  410 . After that, the instruction stream is transmitted from the WiFi router  410  to the cloud server. 
     The third communication management unit  223 J further includes a home appliance communication unit  228 J. The home appliance communication unit  228 J transmits the operation command generated by the cloud server from the antenna unit  270 J to the WiFi router  410 . After that, the operation command is transmitted from the WiFi router  410  to a home electric appliance. As a result, the home electric appliance operates in accordance with the operation command. 
     Embodiment 23 
     As described in connection with Embodiment 11, the base unit may be connected to a smartphone using WiFi communication technology. In Embodiment 23, a description will be given of a base unit connected to a smartphone so that the base unit and the smartphone can communicate with each other using WiFi communication technology. 
       FIG. 25  is a schematic block diagram of a base unit  201 K according to Embodiment 23. The base unit  201 K will be described with reference to  FIG. 11  and  FIG. 25 . Numerals common to Embodiment 22 and Embodiment 23 designate components having substantially the same function as those in Embodiment 22. Thus, these components are identified using the description made in Embodiment 22. 
     The base unit  201 K is connected to the telephone handset  301  and the wearable terminals  303  and  304  so that the base unit  201 K can communicate with the telephone handset  301  and the wearable terminals  303  and  304  through a TDD-TDMA scheme complying with the DECT standard. Accordingly, the base unit  201 K may be used as the base unit  201  described with reference to  FIG. 11 . 
     Similarly to Embodiment 22, the base unit  201 K includes a power supply unit  290 , an audio processing unit  240 , and an interface unit  250 . These components are identified using the description made in Embodiment 22. 
     The base unit  201 K further includes an integrated circuit  260 K and an antenna unit  270 K. The antenna unit  270 K receives signals from the telephone handset  301  and the wearable terminals  303  and  304  through a multiplexing scheme. The integrated circuit  260 K processes the signals received by the antenna unit  270 K. 
     Similarly to Embodiment 22, the integrated circuit  260 K includes a determination unit  211 , an encoding unit  212 , and an I/O section  230 . These components are identified using the description made in Embodiment 22. 
     The integrated circuit  260 K further includes a communication management unit  220 K. The communication management unit  220 K manages communication with the fixed telephone network FTN and the WiFi router  410 . 
     Similarly to Embodiment 22, the communication management unit  220 K includes a first communication management unit  221 , a second communication management unit  222 , and a third communication management unit  223 J. These components are identified using the description made in Embodiment 22. 
     The communication management unit  220 K further includes a fourth communication management unit  224 . The antenna unit  270 K receives signals from the WiFi router  410  and the smartphone  430 . Additionally, the antenna unit  270 K transmits a signal to the WiFi router  410  and the smartphone  430 . The antenna unit  270 K is connected to the second communication management unit  222 , the third communication management unit  223 J, and the fourth communication management unit  224 . The fourth communication management unit  224  manages communication with the smartphone  430 . 
     When the user operates the smartphone  430  to request to make a conversation with an intended party via the fixed telephone network FTN, the antenna unit  270 K receives an audio signal representing the audio input to the smartphone  430 . After that, the fourth communication management unit  224  outputs the audio signal to the first communication management unit  221 . The first communication management unit  221  transmits the audio signal to the telephone of the intended party. 
     Embodiment 24 
     The base unit may be connected to an IP telephone network. In Embodiment 24, a description will be given of a base unit connected to an Internet Protocol (IP) telephone network and a control system including the base unit. 
       FIG. 26A  is a conceptual diagram of a control system  402 L according to Embodiment 24.  FIG. 26B  is a schematic block diagram of a base unit  201 L in the control system  402 L. The control system  402 L will be described with reference to  FIG. 26A  and  FIG. 26B . Numerals common to Embodiment 11, Embodiment 23, and Embodiment 24 designate components having substantially the same function as those in Embodiment 11 and/or Embodiment 23. Thus, these components are identified using the description made in Embodiment 11 and/or Embodiment 23. 
     Similarly to Embodiment 11, the control system  402 L includes a cloud server  420  and a smartphone  430 . These components are identified using the description made in Embodiment 11. 
     The control system  402 L further includes a cordless telephone device  103 L and a WiFi router  410 L. 
     Similarly to Embodiment 11, the cordless telephone device  103 L includes a telephone handset  301  and two wearable terminals  303  and  304 . These components are identified using the description made in Embodiment 11. 
     The cordless telephone device  103 L includes a base unit  201 L. The base unit  201 L is connected to the WiFi router  410 L, the smartphone  430 , and the fixed telephone network FTN so that the base unit  201 L can communicate with the WiFi router  410 L, the smartphone  430 , and the fixed telephone network FTN. The base unit  201 L is connected to the telephone handset  301  and the wearable terminals  303  and  304  so that the base unit  201 L can communicate with the telephone handset  301  and the wearable terminals  303  and  304  through a TDD-TDMA scheme complying with the DECT standard. 
     The WiFi router  410 L is connected to the cloud server  420  and an IP telephone network ITN. This enables the user to have a conversation with an intended party via the IP telephone network ITN. 
     Similarly to Embodiment 23, the base unit  201 L includes a power supply unit  290 , an audio processing unit  240 , and an interface unit  250 . These components are identified using the description made in Embodiment 23. 
     The base unit  201 L further includes an integrated circuit  260 L and an antenna unit  270 L. The antenna unit  270 L receives signals from the telephone handset  301  and the wearable terminals  303  and  304  through a multiplexing scheme. The integrated circuit  260 L processes the signals received by the antenna unit  270 L. 
     Similarly to Embodiment 23, the integrated circuit  260 L includes a determination unit  211 , an encoding unit  212 , and an I/O section  230 . These components are identified using the description made in Embodiment 23. 
     The integrated circuit  260 L further includes a communication management unit  220 L. The communication management unit  220 L manages communication with the fixed telephone network FTN and the WiFi router  410 L. 
     Similarly to Embodiment 23, the communication management unit  220 L includes a first communication management unit  221 , a second communication management unit  222 , a third communication management unit  223 J, and a fourth communication management unit  224 . These components are identified using the description made in Embodiment 23. 
     The communication management unit  220 L further includes a fifth communication management unit  225 . The antenna unit  270 L receives signals from the WiFi router  410 L and the smartphone  430 . Additionally, the antenna unit  270 L transmits a signal to the WiFi router  410 L and the smartphone  430 . The antenna unit  270 L is connected to the second communication management unit  222 , the third communication management unit  223 J, the fourth communication management unit  224 , and the fifth communication management unit  225 . The fifth communication management unit  225  manages communication with the IP telephone network ITN. When the user requests to make a conversation with an intended party via the IP telephone network ITN, the fifth communication management unit  225  manages the communication of signals via the IP telephone network ITN. 
     Embodiment 25 
     As described in connection with Embodiment 8, the control system may include a plurality of telephone handsets. The plurality of telephone handsets may be located in different rooms. In this case, a home electric appliance installed in a room where the telephone handset in use is located may be preferentially subject to remote control. In Embodiment 25, a description will be given of a control system including a plurality of telephone handsets. 
       FIG. 27  is a conceptual diagram of a control system  400 M according to Embodiment 25. The control system  400 M will be described with reference to  FIG. 27 . Numerals common to Embodiment 8 and Embodiment 25 designate components having substantially the same function as those in Embodiment 8. Thus, these components are identified using the description made in Embodiment 8. 
     Similarly to Embodiment 8, the control system  400 M includes a base unit  201  and a WiFi router  410 . These components are identified using the description made in Embodiment 8. 
     The control system  400 M further includes three telephone handsets (a telephone handset (A), a telephone handset (B), and a telephone handset (C)) and a cloud server  420 M. The telephone handset (A) is located in a bedroom. The telephone handset (B) is located in a nursery room (1). The telephone handset (C) is located in a nursery room (2). 
     When the user requests to take remote control of a home electric appliance using the telephone handset (A), the cloud server  420 M preferentially generates an operation command for the remote control of a home electric appliance installed in the bedroom. When the user requests to take remote control of a home electric appliance using the telephone handset (B), the cloud server  420 M preferentially generates an operation command for the remote control of a home electric appliance installed in the nursery room (1). When the user requests to take remote control of a home electric appliance using the telephone handset (C), the cloud server  420 M preferentially generates an operation command for the remote control of a home electric appliance installed in the nursery room (2). 
     Similarly to Embodiment 8, the control system  400 M includes an authentication unit  421 , a speech recognition unit  422 , an interaction unit  423 , an operation command generation unit  424 , and an operation history database  426 . These components are identified using the description made in Embodiment 8. 
     The control system  400 M further includes a target device database  425 M. The target device database  425 M stores data for setting priorities for home electric appliances to be controlled. 
       FIG. 28  is a table showing illustrative data stored in the target device database  425 M. The data stored in the target device database  425 M will be described with reference to  FIG. 27  and  FIG. 28 . 
     As illustrated in  FIG. 27 , the user has seven lighting devices. In some cases, it may be difficult for the speech recognition unit  422  to recognize which lighting device among the seven lighting devices the user wishes to take remote control of. In response to a request from the user using the telephone handset (A) to turn on a lighting device, the operation command generation unit  424  refers to the target device database  425 M and the operation history database  426 . If the lighting device (A) is on while the lighting device (D) is off, the operation command generation unit  424  selects the lighting device (D) as the target of remote control. 
     Embodiment 26 
     As described in connection with Embodiment 9, a handset connected to a base unit so that the handset and the base unit can communicate with each other may be designed as a wearable terminal. Since a wearable terminal changes its position as the user wearing it moves, the wearable terminal may have a function to acquire position information. In this case, the control system may refer to the position of the wearable terminal and determine a home electric appliance to be subject to remote control. In Embodiment 26, a description will be given of a wearable terminal having a function to acquire position information. 
       FIG. 29  is a schematic block diagram of a wearable terminal  300 N according to Embodiment 26. The wearable terminal  300 N will be described with reference to  FIG. 29 . Numerals common to Embodiment 9 and Embodiment 26 designate components having substantially the same function as those in Embodiment 9. Thus, these components are identified using the description made in Embodiment 9. 
     The designer may design the wearable terminal  300 N so that the wearable terminal  300 N is wearable on a user&#39;s wrist. In this case, the designer may determine the design of the wearable terminal  300 N so that the wearable terminal  300 N looks like a watch or a bangle. The designer may design the wearable terminal  300 N so that the wearable terminal  300 N is wearable on a user&#39;s finger. In this case, the designer may determine the design of the wearable terminal  300 N so that the wearable terminal  300 N looks like a ring. The designer may design the wearable terminal  300 N so that the wearable terminal  300 N can hang from the user&#39;s neck. In this case, the designer may determine the design of the wearable terminal  300 N so that the wearable terminal  300 N looks like a pendant or a necklace. The basic concept of this embodiment is not limited to a specific position at which the wearable terminal  300 N is worn or a specific design of the wearable terminal  300 N. 
     Similarly to Embodiment 9, the wearable terminal  300 N includes a signal conversion unit  310 D, an antenna unit  331 , a power button  340 B, and a power supply unit  350 . These components are identified using the description made in Embodiment 9. 
     The wearable terminal  300 N further includes an integrated circuit  320 N. Similarly to Embodiment 9, the integrated circuit  320 N is responsible for various forms of signal processing such as signal processing for establishing a connection with the telephone of the intended party, signal processing for switching the operation mode between the first operation mode and the second operation mode, signal processing for generating bit information and streams, and signal processing for authenticating the user. The signal processing technique described in connection with Embodiment 9 is applied to the integrated circuit  320 N. 
     Similarly to Embodiment 9, the integrated circuit  320 N includes a control unit  321 D, an encoding unit  322 , an I/O section  323 , a timer  324 , a storage unit  325 , an authentication unit  326 , and a communication unit  332 . 
     The integrated circuit  320 N further includes a position information acquisition unit  327 . The position information acquisition unit  327  acquires position information concerning the position of the wearable terminal  300 N by using global positioning system (GPS) technology. The position information acquisition unit  327  generates a position signal representing the position information. The position signal is output from the position information acquisition unit  327  to the communication unit  332 . The communication unit  332  transmits the position signal from the antenna unit  331 . 
       FIG. 30  is a conceptual diagram of a control system  400 N including the wearable terminal  300 N. The control system  400 N will be described with reference to  FIG. 30 . Numerals common to Embodiment 25 and Embodiment 26 designate components having substantially the same function as those in Embodiment 25. Thus, these components are identified using the description made in Embodiment 25. 
     Similarly to Embodiment 25, the control system  400 N includes a base unit  201 , a WiFi router  410 , a telephone handset (A), and a cloud server  420 M. These components are identified using the description made in Embodiment 25. 
     The control system  400 N further includes the wearable terminal  300 N described above. The wearable terminal  300 N is located in the nursery room (2). 
       FIG. 31  is a table showing illustrative data stored in the target device database  425 M. The data stored in the target device database  425 M will be described with reference to  FIG. 30  and  FIG. 31 . 
     As illustrated in  FIG. 30 , the user has seven lighting devices. In some cases, it may be difficult for the speech recognition unit  422  to recognize which lighting device among the seven lighting devices the user wishes to take remote control of. In response to a request from the user using the wearable terminal  300 N in the nursery room (2) to turn on a lighting device, the operation command generation unit  424  refers to the target device database  425 M and the operation history database  426 . If the lighting device (C) is on while the lighting device (D) is off, the operation command generation unit  424  selects the lighting device (D) as the target of remote control. 
     Embodiment 27 
     A home electric appliance group that is controllable by the control system described in connection with Embodiment 8 may include a controller for controlling a home electric appliance. In Embodiment 27, a description will be given of an illustrative method for using a control system will be described. 
       FIG. 32  is a conceptual diagram of a method for using the control system  400 . An illustrative method for using the control system  400  will be described with reference to  FIG. 32 . 
     The control system  400  is configured to directly control a first home electric appliance group APG1. An operation command generated by the control system  400  is transmitted to the first home electric appliance group APG1 via the WiFi router  410  or Ethernet. 
     The first home electric appliance group APG1 includes infrared (IR) converters AP11 and AP12, a lighting device AP13, an air conditioner AP14, a television device AP15, a video device AP16, a refrigerator AP17, a microwave oven AP18, and a washing machine AP19. The IR converters AP11 and AP12 generate a control signal (infrared signal) for controlling a second home electric appliance group APG2 in accordance with an operation command received from the control system  400 . The control signal is transmitted from the IR converters AP11 and AP12 to the second home electric appliance group APG2. 
     The second home electric appliance group APG2 includes lighting devices AP21 and AP22, air conditioners AP23 and AP24, a television device AP25, and a video device AP26. The IR converters AP11 and AP12 refer to the operation command, and select a home electric appliance to be operated from within the second home electric appliance group APG2. The IR converters AP11 and AP12 transmit a control signal to the selected home electric appliance. The selected home electric appliance executes the operation specified by the control signal. 
     Embodiment 28 
     The control system described in connection with the various embodiments described above may employ the DECT standard for communication between the handset and the base unit. The DECT standard specifies the use of audio codec schemes such as 32 kbit/s full term (Adaptive Differential Pulse Code Modulation (ADPCM)) G.726, 64 kbit/s Pulse Code Modulation (PCM) G.711, Wideband speech codec G.722 at 64 kbit/s, Wideband speech codec G.729.1 up to 32 kbit/s, 64 kbit/s Moving Picture Expert Group 4 (MPEG-4) Error Resilient (ER) Advanced Audio Coding-Low Delay (AAC-LD) codec, and 32 kbit/s MPEC-4 ER AAC-LD codec. The handset may use one of the above-described audio codec schemes to encode a call stream. The handset may use another of the above-described audio codec schemes to encode an instruction stream. In this case, the use of different audio codec schemes may serve as an index for differentiating the call stream and the instruction stream from each other, resulting in a reduction in the number of bits of a signal transmitted from the handset to the base unit. For example, the instruction stream may be encoded using an audio encoding scheme with a higher bit rate than the call stream. In Embodiment 28, a description will be given of a wearable terminal configured to encode an instruction stream using an audio encoding scheme different from that of a call stream. 
       FIG. 33  is a schematic block diagram of a wearable terminal  300 P according to Embodiment 28. The wearable terminal  300 P will be described with reference to  FIG. 10  and  FIG. 33 . Numerals common to Embodiment 9 and Embodiment 28 designate components having substantially the same function as those in Embodiment 9. Thus, these components are identified using the description made in Embodiment 9. 
     The wearable terminal  300 P may be used as each of the wearable terminals  303  and  304  described with reference to  FIG. 10 . Accordingly, the wearable terminal  300 P is connected to the base unit  201  so that the wearable terminal  300 P and the base unit  201  can communicate with each other through a multiplexing scheme complying with the DECT standard. 
     Similarly to Embodiment 9, the wearable terminal  300 P includes a signal conversion unit  310 D, an antenna unit  331 , a power button  340 B, and a power supply unit  350 . These components are identified using the description made in Embodiment 9. 
     The wearable terminal  300 P further includes an integrated circuit  320 P. The integrated circuit  320 P is responsible for various forms of signal processing such as signal processing for establishing a connection with the telephone of the intended party, signal processing for switching the operation mode between the first operation mode and the second operation mode, and signal processing for authenticating the user. The signal processing technique described in connection with Embodiment 9 is applied to the integrated circuit  320 P. 
     Similarly to Embodiment 9, the integrated circuit  320 P includes a control unit  321 D, an I/O section  323 , a timer  324 , a storage unit  325 , an authentication unit  326 , and a communication unit  332 . These components are identified using the description made in Embodiment 9. 
     The integrated circuit  320 P further includes an encoding unit  322 P. The encoding unit  322 P includes a call encoding unit  328  and an instruction encoding unit  329 . The call encoding unit  328  encodes a call stream. The instruction encoding unit  329  encodes an instruction stream. 
     For example, the call encoding unit  328  may encode a call stream using 32 kbit/s full term (ADPCM) G.726. The instruction encoding unit  329  may encode an instruction stream using 64 kbit/s PCM G.711 or 64 kbit/s MPEG-4 ER AAC-LD codec. 
     Embodiment 29 
     Similarly to the handset described in connection with Embodiment 28, the base unit may execute an encoding process using an audio codec scheme complying with the DECT standard. The DECT standard specifies the use of audio codec schemes such as 32 kbit/s full term (ADPCM) G.726, 64 kbit/s PCM G.711, Wideband speech codec G.722 at 64 kbit/s, Wideband speech codec G.729.1 up to 32 kbit/s, 64 kbit/s MPEG-4 ER AAC-LD codec, and 32 kbit/s MPEC-4 ER AAC-LD codec. The base unit may use one of the above-described audio codec schemes to encode a call stream. The base unit may use another of the above-described audio codec schemes to encode an instruction stream. In this case, the use of different audio codec schemes may serve as an index for differentiating the call stream and the instruction stream from each other, resulting in a reduction in the number of bits of a signal used for communication between the handset and the base unit. For example, the instruction stream may be encoded using an audio encoding scheme with a higher bit rate than the call stream. In Embodiment 29, a description will be given of a base unit configured to encode an instruction stream using an audio encoding scheme different from that of a call stream. 
       FIG. 34  is a schematic block diagram of a base unit  201 Q according to Embodiment 29. The base unit  201 Q will be described with reference to  FIG. 34 . Numerals common to Embodiment 22 and Embodiment 29 designate components having substantially the same function as those in Embodiment 22. Thus, these components are identified using the description made in Embodiment 22. 
     Similarly to Embodiment 22, the base unit  201 Q includes a power supply unit  290 , an audio processing unit  240 , an interface unit  250 , and an antenna unit  270 J. These components are identified using the description made in Embodiment 22. 
     The base unit  201 Q further includes an integrated circuit  260 Q. The integrated circuit  260 Q processes a signal received by the antenna unit  270 J. 
     Similarly to Embodiment 22, the integrated circuit  260 Q includes a determination unit  211 , a communication management unit  220 J, and an I/O section  230 . These components are identified using the description made in Embodiment 22. 
     The integrated circuit  260 Q further includes an encoding unit  212 Q. The encoding unit  212 Q includes a call encoding unit  213  and an instruction encoding unit  214 . The call encoding unit  213  encodes a call stream. Additionally, the call encoding unit  213  encodes an electrical signal generated by the microphone  242 . The instruction encoding unit  214  encodes an instruction stream. 
     For example, the call encoding unit  213  may encode the call stream using 32 kbit/s full term (ADPCM) G.726. The instruction encoding unit  214  may encode the instruction stream using 64 kbit/s PCM G.711 or 64 kbit/s MPEG-4 ER AAC-LD codec. 
     Embodiment 30 
     The instruction stream described in connection with the various embodiments described above is transmitted to a cloud server via a public communication line different from the public communication line used for the transmission of the call stream. Alternatively, the instruction stream may be transmitted or received using a public communication line that is common to the call stream. In Embodiment 30, a description will be given of a control system that uses a common public communication line for the communication of the call stream and the instruction stream. 
       FIG. 35  is a conceptual diagram of a control system  402 R according to Embodiment 30. The control system  402 R will be described with reference to  FIG. 35 . Numerals common to Embodiment 11 and Embodiment 30 designate components having substantially the same function as those in Embodiment 11. Thus, these components are identified using the description made in Embodiment 11. 
     Similarly to Embodiment 11, the control system  402 R includes a telephone handset  301 , two wearable terminals  303  and  304 , a cloud server  420 , and a smartphone  430 . These components are identified using the description made in Embodiment 11. 
     The control system  402 R further includes a base unit  201 R. Similarly to Embodiment 11, the base unit  201 R has the function of a telephone, and the function of a home gateway. Additionally, the base unit  201 R also has the function of a WiFi router. 
     The base unit  201 R enables a user to have a conversation with an intended party via the smartphone  430  and via the mobile telephone network MTN in accordance with the subscriber identity module (SIM) identity allocated to the smartphone  430 . The user is also able to have a conversation with an intended party via the mobile telephone network MTN by using the telephone handset  301  or the wearable terminal  303  or  304 . Accordingly, the call stream is communicated via the mobile telephone network MTN. 
     The subscription to use the mobile telephone network MTN may involve an authentication process for allocating SIM identity to the telephone handset  301 , the wearable terminals  303  and  304 , the base unit  201 R, and the smartphone  430 . 
     Similarly to the call stream, the instruction stream is transmitted to the cloud server  420  via the mobile telephone network MTN. The operation command is transmitted to the base unit  201 R via the mobile telephone network MTN. Accordingly, the subscription for the same line enables the user to seamlessly perform operations, that is, making a telephone call and taking remote control of a home electric appliance. This may improve user convenience. Additionally, the basic concept of this embodiment is beneficial to the user in terms of the fee for the line for telephone calls. In this embodiment, the common public communication line is exemplified by a communication line including the mobile telephone network MTN. The second instruction stream is exemplified by the instruction stream output from the base unit  201 R. The second call stream is exemplified by the call stream output from the base unit  201 R. 
     Embodiment 31 
     The wearable terminal described in connection with the various embodiments described above generates instruction bit information and an instruction stream in accordance with an operation of a power button. Alternatively, the wearable terminal may generate instruction bit information and an instruction stream in response to a specific gesture performed by the user. In Embodiment 31, a description will be given of a wearable terminal that generates instruction bit information and an instruction stream in accordance with a gesture of a user. 
       FIG. 36  is a schematic block diagram of a wearable terminal  300 S according to Embodiment 31. The wearable terminal  300 S will be described with reference to  FIG. 36 . Numerals common to Embodiment 9 and Embodiment 31 designate components having substantially the same function as those in Embodiment 9. Thus, these components are identified using the description made in Embodiment 9. 
     The wearable terminal  300 S is designed to be wearable on a user&#39;s upper limb. The term “upper limb”, as used herein, refers to a body portion of a user extending from the shoulder to the fingertip. The wearable terminal  300 S may be designed to be wearable on a user&#39;s wrist. Alternatively, the wearable terminal  300 S may be designed to be wearable on a user&#39;s finger. The basic concept of this embodiment is not limited to a specific position at which is the wearable terminal  300 S is worn. 
     When the wearable terminal  300 S is designed to be wearable on a user&#39;s wrist, the wearable terminal  300 S may look like a watch. When the wearable terminal  300 S is designed to be wearable on a user&#39;s finger, the wearable terminal  300 S may look like a ring. The designer of the wearable terminal  300 S may determine the design of the wearable terminal  300 S so as to be suitable for the position at which the wearable terminal  300 S is worn. Accordingly, the basic concept of this embodiment is not limited to a specific design of the wearable terminal  300 S. 
     Similarly to Embodiment 9, the wearable terminal  300 S includes a signal conversion unit  310 D, an integrated circuit  320 D, an antenna unit  331 , and a power supply unit  350 . These components are identified using the description made in Embodiment 9. 
     The wearable terminal  300 S further includes a power button  340 S and a gesture sensing circuit  360 . Similarly to Embodiment 9, the power button  340 S is used to determine whether to supply power from the power supply unit  350  or to stop the supply of power from the power supply unit  350 . Unlike Embodiment 9, a trigger signal for requesting the generation of instruction bit information and an instruction stream is generated by the gesture sensing circuit  360  rather than the power button  340 S. 
     The gesture sensing circuit  360  includes a motion sensor  361  and a gesture determination unit  362 . The motion sensor  361  detects a motion of the upper limb. The motion sensor  361  outputs motion data representing the motion of the upper limb. The motion sensor  361  may be an acceleration sensor. Alternatively, the motion sensor  361  may be an angular velocity sensor. The gesture determination unit  362  determines, based on the motion data, whether or not the user has requested the generation of instruction bit information and an instruction stream. When determining that the user has requested the generation of instruction bit information and an instruction stream, the gesture determination unit  362  generates a trigger signal. The trigger signal is output from the gesture determination unit  362  to the control unit  321 D. 
       FIG. 37  is a conceptual diagram of a three-dimensional coordinate system that is set for the upper limb. A motion detection technique of the motion sensor  361  will be described with reference to  FIG. 36  and  FIG. 37 . 
     The motion sensor  361  detects a motion of the upper limb in the direction of a first axis DVX. A coordinate axis extending along the extended upper limb, from the shoulder to the fingertip, in the vertically downward oriented direction of the upper limb is hereinafter referred to as a second axis PDX. A coordinate axis perpendicular to the second axis PDX and extending in the direction of movement of the user is hereinafter referred to as a third axis FBX. The first axis DVX is perpendicular to a coordinate plane defined by the second axis PDX and the third axis FBX. 
     The motion sensor  361  detects a movement of the upper limb in the extending direction of the first axis DVX perpendicular to the coordinate plane defined by the second axis PDX and the third axis FBX. A detection axis of a sensor used as the motion sensor  361  may be perpendicular to the coordinate plane defined by the second axis PDX and the third axis FBX. In this case, the motion sensor  361  may be able to accurately sense a motion (e.g., acceleration and/or angular velocity) in the direction extending along the first axis DVX. Alternatively, a detection axis of a sensor used as the motion sensor  361  may be inclined at an angle larger than 0° and smaller than 90° with respect to the coordinate plane defined by the second axis PDX and the third axis FBX. In this case, the motion sensor  361  can sense not only a motion in the direction extending along the first axis DVX but also a motion in a direction extending along the coordinate plane defined by the second axis PDX and the third axis FBX. The gesture determination unit  362  may apply a predetermined vector operation to the motion data output from the motion sensor  361 , and individually evaluate the motion in the direction extending along the first axis DVX and the motion in the direction extending along the coordinate plane defined by the second axis PDX and the third axis FBX. The basic concept of this embodiment is not limited to a specific angle at which a detection axis of a sensor intersects the coordinate plane defined by the second axis PDX and the third axis FBX. 
     While the user is walking, the upper limbs frequently move in the direction indicated by the third axis FBX. When the user attempts to pick up an object far in front of them, the upper limb is extended, causing the wearable terminal  300 S to be likely to move in the direction indicated by the second axis PDX. When the user attempts to pick up an object in front of their chest, the upper limb bends, causing the wearable terminal  300 S to be likely to move in the direction indicated by the second axis PDX. The user&#39;s motions described above frequently occur. By comparison with motions in the directions indicated by the third axis FBX and the second axis PDX, the motion of the upper limb in the direction indicated by the first axis DVX does not frequently occur. That is, the user does not usually move the upper limb quickly and/or a large amount in the direction indicated by the first axis DVX. 
     When the motion sensor  361  senses a motion of the upper limb (i.e., the wearable terminal  300 S) in the direction indicated by the first axis DVX, the instruction bit information and the instruction stream are generated under control of the control unit  321 D. Thus, the remote control of a home electric appliance is not likely to start in response to an accidental or unintentional movement of the user. This may prevent or reduce inadvertent or unintentional operation of the home electric appliance. 
       FIG. 38  is a table depicting illustrative relationships between operations demanded by the user and operations performed on the wearable terminal  300 S. Illustrative relationships between operations demanded by the user and operations performed on the wearable terminal  300 S will be described with reference to  FIG. 36  to  FIG. 38 . 
     When the user wishes to take remote control of a home electric appliance, the user may move the upper limb on which the wearable terminal  300 S is worn in the direction indicated by the first axis DVX. When the user wishes to make a telephone call using the wearable terminal  300 S, the user may press the power button  340 S. When the user wishes to answer an incoming call on a smartphone with the wearable terminal  300 S, the user may touch the touch panel  311 D. 
     The basic concepts of the various embodiments described above may be used in combination to meet the request to control a home electric appliance. 
     The basic concepts of the embodiments described above are suitable for use in the control of a home electric appliance.