Patent Publication Number: US-11665390-B2

Title: Mobile information terminal

Description:
TECHNICAL FIELD 
     The present invention relates to a mobile information terminal. 
     BACKGROUND ART 
     A mobile information terminal such as a mobile phone, a smartphone, or a tablet terminal is generally used for content viewing. For example, with the use of a content distribution service, it is possible for a user to view, for example, video content (moving image, still image) or audio content downloaded or streaming from a server on a network to a mobile information terminal. Particularly, contents such as moving images have become significantly larger in size in recent years as the resolution of the contents becomes higher. 
     However, the following Patent Literature 1 describes that “to become smartphone users, most of such users tend to subscribe to flat-rate communication charge plans (generally called “Pake-hodai”). These plans allow users to view web sites or video sites without worrying about the cost, thereby accelerating the increase in data communication amount. On the other hand, a large difference in data communication amount arises among users, and, in reality, a significant amount of use by some heavy users pushes up the entire communication amount. Thus, flat-rate charges are increased for facility enhancement, which will result in unfairness among users. Accordingly, some of the carriers have begun to take measures for reducing the entire data communication amount by limiting a bandwidth used by each of the users who have performed communication of extremely large amount of data.” 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2013-058994A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In fact, some of the mobile phone carriers in Japan impose limitations on communication speed for the purposes of, for example, preventing their lines from being occupied by some heavy users. The purpose of such limitations on communication speed is to force a data communication speed to be a lower speed when the total data communication amount through mobile phone network communication in a communication system such as wideband code division multiple access (W-CDMA) (registered trademark) or long term evolution (LTE) in a predetermined period exceeds a predetermined value. For example, once the total data communication amount in a month exceeds 7.0 GB, the subsequent data communication speed is limited to less than or equal to 128 kbps within the month. That is, it can be said that the data capacity within which high-speed data communication is possible is predetermined for each predetermined period in mobile phone network communication systems of the mobile phone carriers. 
     Thus, a user uses the above-described content distribution service to, for example, download large moving-image content or view such content in the form of streaming data at the early time of the predetermined period and uses up the data communication capacity within which high-speed data communication is possible, the subsequent use of the service may become inconvenient for the user. Therefore, when the content distribution service that requires communication of large amount of data is used, it is desirable to perform communication control or the like that takes the data communication amount into consideration. The Patent Literature 1 describes a technique that imposes a limitation on data communication amount, but it does not describe communication control based on a data communication amount. 
     An object of the present invention is to provide a mobile information terminal that provides high usability when content viewing is performed. 
     Solution to Problem 
     The techniques described in the claims are used as means for solving the problem described above. 
     Examples of the techniques used herein include a mobile information terminal that performs data transmission and reception, the data transmission and reception including video data reception. The mobile information terminal includes a communication management execution module that obtains a communication amount of data transmitted and received by the mobile information terminal in a predetermined period, and a remote viewing execution module that compares the obtained communication amount to a preset predetermined value and makes an image quality of the video data selectable according to a relationship between the obtained communication amount and the predetermined value. 
     Advantageous Effects of Invention 
     Employing the present invention makes it possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a diagram illustrating an example of a system configuration of a communication system. 
         FIG.  2 A  is a diagram illustrating an example of a block configuration of a mobile information terminal. 
         FIG.  2 B  is a diagram illustrating an example of a software configuration of the mobile information terminal. 
         FIG.  3    is a diagram illustrating an example of a block configuration of a broadcast receiver. 
         FIG.  4    is a diagram illustrating an example of an operation sequence performed during the execution of a remote viewing function of the mobile information terminal. 
         FIG.  5 A  is a diagram illustrating a display example of a basic screen of the mobile information terminal. 
         FIG.  5 B  is a diagram illustrating a display example of a program type selection screen of the mobile information terminal. 
         FIG.  5 C  is a diagram illustrating a display example of a program guide screen of the mobile information terminal. 
         FIG.  5 D  is a diagram illustrating a display example of a remote image quality selection screen of the mobile information terminal. 
         FIG.  5 E  is a diagram illustrating a display example of a remote viewing screen of the mobile information terminal. 
         FIG.  6 A  is a diagram illustrating an example of control of remote viewing image quality according to a total data communication amount of the mobile information terminal. 
         FIG.  6 B  is a diagram illustrating an example of control of the remote viewing image quality according to the total data communication amount of the mobile information terminal and a period. 
         FIG.  7 A  is a diagram illustrating an example of a display format of a remote image quality selection box that imposes a limitation on the selection thereof. 
         FIG.  7 B  is a diagram illustrating an example of a display format of the remote image quality selection box that does not impose a limitation on the selection thereof. 
         FIG.  8    is a diagram illustrating a display example of a remote image quality selection screen of the mobile information terminal including viewable times. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     Examples of an embodiment of the present invention will be described below with reference to the drawings. 
     System Configuration 
       FIG.  1    is a system configuration diagram illustrating an example of a communication system including a mobile information terminal of the present example. The communication system of the present example includes a mobile information terminal  100 , a broadband network  200  such as the Internet, an access point  200   a , a router  200   r , a mobile phone communication server  300 , a base station  300   b  of a mobile phone communication network, a broadcast receiver  400 , an antenna  400   a , a broadcasting tower  400   t  of a broadcasting station, and an additional application server  500 . 
     The mobile information terminal  100  has telephone communication (phone call) and data transmission and reception capabilities via a mobile phone network, and a wireless communication capability using, for example, Wi-Fi (registered trademark). The mobile information terminal  100  is capable of connecting to the Internet  200  via the outdoor access point  200   a  or via the base station  300   b  and mobile phone communication server  300  of the mobile phone communication network. In addition, the mobile information terminal  100  is capable of communicating with each server on the Internet  200  for data transmission and reception. Additionally, the mobile information terminal  100  has a capability to play back, for example, video content (moving image, still image) or audio content obtained from each server on the Internet  200 . 
     The mobile information terminal  100  may be, for example, a mobile phone, a smartphone, or a tablet terminal. The mobile information terminal  100  may also be, for example, a personal digital assistant (PDA), a laptop personal computer (PC), or an electronic book reader. Furthermore, the mobile information terminal  100  may be, for example, a digital still camera, a video camera capable of capturing videos, a mobile game console, a navigation device, or any other mobile digital device. 
     The access point  200   a  is connected with the Internet  200  through wired communication and connected with the mobile information terminal  100  through wireless communication such as Wi-Fi. This configuration allows the mobile information terminal  100  and each server on the Internet  200  to mutually transmit and receive data via the access point  200   a.    
     The mobile phone communication server  300  is connected with the Internet  200  and connected with the mobile information terminal  100  via the base station  300   b . The mobile phone communication server  300  manages telephone communication (phone call) and data transmission and reception, via the mobile phone communication network, of the mobile information terminal  100  and allows data transmission and reception through the communication between the mobile information terminal  100  and each server on the Internet  200 . The mobile information terminal  100  and the base station  300   b  may communicate with each other in the W-CDMA system, LTE system, or any other communication system. 
     The broadcast receiver  400  is a television receiver that receives and displays a digital broadcast wave transmitted from the broadcasting tower  400   t  of the broadcasting station via the antenna  400   a . The broadcast receiver  400  may be, for example, an optical disc drive recorder such as a digital versatile disc (DVD) recorder, a magnetic disk drive recorder such as a hard disc drive (HDD) recorder, or a set top box (STB). The broadcast receiver  400  may also be, for example, a PC, a tablet terminal, or a game console that is capable of receiving a digital broadcast. 
     Note that the broadcast receiver  400  is capable of connecting with the Internet  200  via the in-house router  200   r  and is capable of communicating with each server on the Internet  200  for data transmission and reception. 
     The router  200   r  is connected with the Internet  200  through wired communication and is connected with the broadcast receiver  400  through wireless communication or wired communication. Furthermore, the router  200   r  may be connected with the mobile information terminal  100  through wireless communication such as Wi-Fi. This configuration allows each server on the Internet  200 , the broadcast receiver  400 , and the mobile information terminal  100  to mutually transmit and receive data via the router  200   r . Note that the broadcast receiver  400  and the mobile information terminal  100  may communicate directly, namely, not via the router  200   r , with each other in a system such as BlueTooth (registered trademark) or near field communication (NFC). 
     The additional application server  500  is a known server that performs, for example, storage, management, and distribution of general applications, operation programs, and various contents and data. There may be more than one additional application server  500  on the Internet  200 . 
     Hardware Configuration of Mobile Information Terminal 
       FIG.  2 A  is a block diagram illustrating an example of the internal configuration of the mobile information terminal  100 . The mobile information terminal  100  includes a main controller  101 , a system bus  102 , a ROM  103 , a RAM  104 , a storage unit  110 , a communication processor  120 , an extended interface  124 , an operation unit  130 , an image processor  140 , an audio processor  150 , and a sensor  160 . 
     The main controller  101  is a microprocessor unit that controls the entire mobile information terminal  100 . The system bus  102  is a data communication channel for data transmission and reception between the main controller  101  and each operating block in the mobile information terminal  100 . 
     The read only memory (ROM)  103  is a memory in which a basic operation program, such as an operating system, and other operation programs are stored. For example, a rewritable ROM such as an electrically erasable programmable ROM (EEPROM) or a flash ROM is used. The random access memory (RAM)  104  serves as a work area during the execution of the basic operation program or other operation programs. The ROM  103  and the RAM  104  may be integrated with the main controller  101 . Furthermore, the ROM  103  may be constituted of some storage area in the storage unit  110  rather than an independent element as illustrated in  FIG.  2 A . 
     The storage unit  110  stores, for example, operation programs and operation setting values of the mobile information terminal  100 , and personal information on the user of the mobile information terminal  100 . In addition, an operation program downloaded from a network, various data created by the operation program, and the like can be stored in the storage unit  110 . Furthermore, content such as a moving image, still image, and audio downloaded from a network can be stored in the storage unit  110 . Some area in the storage unit  110  may constitute part or all of the ROM  103 . Furthermore, it is required that the storage unit  110  retain the stored information even with no power supplied from outside to the mobile information terminal  100 . Therefore, for example, a semiconductor memory such as a flash ROM or a solid state drive (SSD), or a magnetic disk drive such as an HDD is used. 
     Note that the operation programs stored in the ROM  103  or the storage unit  110  may be updated or functionally extended through downloading from each server on the Internet  200 . 
     The communication processor  120  includes a local area network (LAN) communication unit  121 , a mobile phone network communication unit  122 , and an NFC communication unit  123 . The LAN communication unit  121  is connected with the Internet  200  via the outdoor access point  200   a  or the in-house router  200   r  and performs data transmission and reception with each server on the Internet  200 . The LAN communication unit  121  is connected with the access point  200   a  or the router  200   r  through wireless connection such as Wi-Fi. The mobile phone network communication unit  122  performs telephone communication (phone call) and data transmission and reception through wireless communication with the base station  300   b  of the mobile phone communication network. The mobile phone network communication unit  122  is connected with the base station  300   b  in a communication system such the W-CDMA system or the LTE system. The NFC communication unit  123  performs wireless communication, with the NFC communication unit  123  in close proximity to a corresponding reader/writer. The LAN communication unit  121 , the mobile phone network communication unit  122 , and the NFC communication unit  123  are each provided with a coding circuit, a decoding circuit, an antenna, and the like. Furthermore, the communication processor  120  may be provided with an additional communication unit such as a BlueTooth communication unit or an infrared communication unit. 
     The extended interface  124  is a group of interfaces for extending the capabilities of the mobile information terminal  100 . The extended interface  124  includes, for example, a video/audio interface, a universal serial bus (USB) interface, and a memory interface in the present example. The video/audio interface receives a video signal/audio signal from an external video/audio output device, outputs a video signal/audio signal to the external video/audio input device, and the like. The USB interface is connected with, for example, a PC to perform data transmission and reception therewith. The USB interface may also be connected with a keyboard or any other USB device. The memory interface is connected with a memory card or any other memory medium to perform data transmission and reception therewith. 
     The operation unit  130  is an instruction-input unit for a user to input an operation instruction to the mobile information terminal  100 . In the present example as illustrated in  FIG.  5 A , the operation unit  130  includes a touch panel  130   t  disposed on a display unit  141  so as to cover the display unit  141 , and operation keys  130   k  that are button switches arranged. The operation unit  130  may include only one of the touch panel  130   t  and the operation keys  130   k . The mobile information terminal  100  may be operated through, for example, a keyboard connected to the extended interface  124 . The mobile information terminal  100  may be operated through a separate mobile terminal device connected through wired communication or wireless communication. Furthermore, the display unit  141  may be provided with the touch panel function. 
     The image processor  140  includes the display unit  141 , an image signal processor  142 , a first image input unit  143 , and a second image input unit  144 . The display unit  141  is, for example, a display device such as a liquid crystal panel and provides image data processed by the image signal processor  142  to the user of the mobile information terminal  100 . The image signal processor  142  is provided with a video RAM (not illustrated) and drives the display unit  141  on the basis of the image data input to the video RAM. The image signal processor  142  has a capability to perform, for example, format conversion, and superimposition of a menu or other on-screen display (OSD) signals as needed. The first image input unit  143  and the second image input unit  144  are camera units for converting light incident through a lens to an electrical signal by using an electronic device such as a charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) sensor to obtain image data of surroundings or an object. 
     The audio processor  150  includes an audio output unit  151 , an audio signal processor  152 , and an audio input unit  153 . The audio output unit  151  is a speaker that provides an audio signal processed by the audio signal processor  152  to the user of the mobile information terminal  100 . The audio input unit  153  is a microphone that converts, for example, a user&#39;s voice to audio data and inputs the audio data. 
     The sensor  160  is a group of sensors for detecting states of the mobile information terminal  100 . The sensor  160  includes, in the present example, a global positioning system (GPS) receiver  161 , a gyrosensor  162 , a magnetic field sensor  163 , an acceleration sensor  164 , an illuminance sensor  165 , and a proximity sensor  166 . The group of sensors makes it possible to detect, for example, a position, inclination, orientation, motion, ambient brightness, and proximity to surrounding objects of the mobile information terminal  100 . The mobile information terminal  100  may further be provided with another sensor such as an atmospheric pressure sensor. 
     Note that although the configuration example of the mobile information terminal  100  illustrated in  FIG.  2 A  includes many components that are not required for the present example, such as the sensor  160 , a configuration even without these components does not impair the effect of the present example. Other components (not illustrated) such as a digital broadcast reception function or an electronic money settlement function may be added. 
     Software Configuration of Mobile Information Terminal 
       FIG.  2 B  is a software configuration diagram of the mobile information terminal  100  of the present example.  FIG.  2 B  illustrates an example of software configurations in the ROM  103 , the RAM  104 , and the storage unit  110 . In the present example, a basic operation program  1001  and other operation programs are stored in the ROM  103 , and a remote viewing program  1002 , a communication management program  1003 , a content playback program  1004 , and other operation programs are stored in the storage unit  110 . Furthermore, the storage unit  110  includes a content storage area  1011  for storing content such as a moving image, still image, and audio, an authentication information storage area  1012  for storing authentication information used for collaborative operation with an external device, and a various information storage area  1019  for storing other various information. 
     The basic operation program  1001  stored in the ROM  103  is loaded in the RAM  104 , and then the main controller  101  executes the loaded basic operation program to configure a basic operation execution module  1101 . Note that, for illustrating this state, the basic operation execution module  1101  is depicted inside the RAM  104  in  FIG.  2 B . The other modules inside the RAM  104 , which will be described below, are depicted in the same way. The remote viewing program  1002 , the communication management program  1003 , and the content playback program  1004  stored in the storage unit  110  are loaded in the RAM  104 , and then the main controller  101  executes the loaded operation programs to configure respective modules, namely, a remote viewing execution module  1102 , a communication management execution module  1103 , and a content playback execution module  1104 . The RAM  104  includes a temporary storage area  1109  for temporarily retaining, for example, data generated during the execution of each operation program as needed. 
     For ease of explanation, a process in which the main controller  101  loads, in the RAM  104 , the basic operation program  1001  stored in the ROM  103  and executes the loaded program to control each operating block will be described below as a process in which the basic operation execution module  1101  controls each operating block. Other operation programs will be described in a similar manner. The detail of each operation execution module will be described later. 
     Each of the operation programs may be pre-stored in the ROM  103  and/or the storage unit  110  before product shipment. The program may be obtained from, for example, the additional application server  500  on the Internet  200  via the LAN communication unit  121  or the mobile phone network communication unit  122  after product shipment. Each of the operation programs stored in, for example, a memory card or optical disc may be obtained via the extended interface  124  or the like. 
     Hardware Configuration of Broadcast Receiver 
       FIG.  3    is a block diagram illustrating an example of the internal configuration of the broadcast receiver  400 . The broadcast receiver  400  includes a main controller  401 , a system bus  402 , a ROM  403 , a RAM  404 , a storage unit  410 , a LAN communication unit  421 , an extended interface  424 , a tuner/demodulator  431 , a demultiplexer  432 , a video decoder  433 , an audio decoder  434 , a subtitle decoder  435 , a data broadcast reception processor  436 , a video superimposing unit  437 , a code converter  440 , a video display unit  451 , a speaker  452 , a video output unit  453 , and an audio output unit  454 . 
     The main controller  401  is a microprocessor unit that controls the entire broadcast receiver  400  according to a predetermined operation program. The system bus  402  is a data communication channel for data transmission and reception between the main controller  401  and each operating block in the broadcast receiver  400 . 
     The ROM  403  is a memory in which a basic operation program, such as an operating system, and other operation programs are stored. For example, a rewritable ROM such as an EEPROM or a flash ROM is used. The RAM  404  serves as a work area during the execution of the basic operation program or other operation programs. 
     The storage unit  410  stores, for example, operation programs and operation setting values of the broadcast receiver  400 , and personal information on the user of the broadcast receiver  400 . In addition, an operation program downloaded from a network, various data created by the operation program, and the like can be stored in the storage unit  410 . Furthermore, content such as a moving image, still image, and audio obtained from a broadcast wave or downloaded from a network can be stored in the storage unit  410 . Some area in the storage unit  410  may constitute part or all of the ROM  403 . 
     The LAN communication unit  421  is connected with the Internet  200  via the in-house router  200   r  and performs data transmission and reception with each server on the Internet  200 . The connection with the router  200   r  may be a wired connection or may be a wireless connection such as Wi-Fi. The LAN communication unit  421  is provided with a coding circuit, a decoding circuit, and the like. Furthermore, the broadcast receiver  400  may be provided with an additional communication unit such as a BlueTooth communication unit, an NFC communication unit, or an infrared communication unit. 
     The tuner/demodulator  431   a  and tuner/demodulator  431   b  receive a digital broadcast wave from the broadcasting tower  400   t  via the antenna  400   a  and tune in to (select) a channel for a service desired by the user under the control of the main controller  401 . Furthermore, the tuner/demodulator  431   a  and tuner/demodulator  431   b  demodulate a broadcast signal in the received digital broadcast wave to obtain a transport stream (TS). Note that the example illustrated in  FIG.  3    includes two tuner/demodulators. The tuner/demodulator  431   a  and tuner/demodulator  431   b  can be controlled independently. In the following, the tuner/demodulator  431   a  and tuner/demodulator  431   b  are not distinguished from each other and referred to as a tuner/demodulator  431 . 
     The demultiplexer  432  receives the TS output from the tuner/demodulator  431  and demultiplexes the TS into data rows such as a video data row, an audio data row, a subtitle data row, a program information data row, and a broadcast markup language (BML) data row. These data rows may be, for example, in the form of an elementary stream (ES). The video decoder  433  decodes the video data row input from the demultiplexer  432  and outputs video information. The audio decoder  434  decodes the audio data row input from the demultiplexer  432  and outputs audio information. The subtitle decoder  435  decodes the subtitle data row input from the demultiplexer  432  and outputs subtitle information. The data broadcast reception processor  436  decodes the BML data row input from the demultiplexer  432  to regenerate a BML document and executes the BML document to output data broadcast screen information. 
     The video superimposing unit  437  receives the video information output from the video decoder  433 , the subtitle information output from the subtitle decoder  435 , and the data broadcast screen information output from the data broadcast reception processor  436  and performs a process such as selection and/or superimposition. The video superimposing unit  437  is provided with a video RAM (not illustrated), and the video display unit  451  and the like are driven on the basis of the video information input in the video RAM. Furthermore, the video superimposing unit  437  performs, for example, a scaling process, and a superimposing process, as needed, on electronic program guide (EPG) screen information created on the basis of the program information data row output from the demultiplexer  432  under the control of the main controller  401 . 
     The code converter  440  performs a transcoding process on the TS output from the tuner/demodulator  431 , the ES output from the demultiplexer  432 , recorded content obtained from the storage unit  110 , or the like to convert, for example, a resolution, a bit rate, or a coding system. 
     The video display unit  451  is, for example, a display device such as a liquid crystal panel that provides, to the user of the broadcast receiver  400 , the video information subjected to the selection process and/or superimposing process by the video superimposing unit  437 . The speaker  452  provides the audio information output from the audio decoder  434  to the user of the broadcast receiver  400 . The video output unit  453  is a video output interface that outputs the video information subjected to the selection process and/or superimposing process by the video superimposing unit  437 . The audio output unit  454  is an audio output interface that outputs the audio information output from the audio decoder  434 . 
     Note that the video output unit  453  and audio output unit  454  are not essential components of the present example in a case where the broadcast receiver  400  is, for example, a television receiver. The video display unit  451  and speaker  452  are not essential components of the present example in a case where the broadcast receiver  400  is, for example, a DVD recorder. 
     The extended interface  424  is a group of interfaces for extending the capabilities of the broadcast receiver  400 . The extended interface  424  includes, for example, a video/audio interface, a USB interface, and a memory interface in the present example. The video/audio interface receives a video signal/audio signal from an external video/audio output device, outputs a video signal/audio signal to the external video/audio input device, and the like. The USB interface is connected with, for example, a PC to perform data transmission and reception therewith. An HDD may be connected to the USB interface to record a broadcast program or downloaded content. The USB interface may also be connected with a keyboard or any other USB device. The memory interface is connected with a memory card or any other memory medium to perform data transmission and reception therewith. 
     Operation Sequence of Mobile Information Terminal 
     An operation of the mobile information terminal  100  of the present example will be described below. 
     Note that a description is given of a case where the mobile information terminal  100  and the broadcast receiver  400  of the present example are provided with a remote viewing function that makes a digital broadcast program or recorded content thereof viewable with, for example, a smartphone or a tablet terminal located away from home via the Internet  200 , such a digital broadcast program being received by, for example, an in-house television receiver or a DVD recorder. 
     Furthermore, in the present example, the data transmission and reception between the mobile information terminal  100  and the Internet  200  is performed by the mobile phone network communication unit  122  via the mobile phone communication server  300  and the base station  300   b . This includes a case where data transmission and reception using the LAN communication unit  121  is impossible due to, for example, no access point  200   a  being located near the mobile information terminal  100 . Furthermore, the data communication function provided by the mobile phone carrier for the mobile information terminal  100  of the present example has a capability to impose a limitation on communication speed. 
       FIG.  4    is an operation sequence diagram illustrating an example of operations performed during the execution of the remote viewing function of the mobile information terminal  100 .  FIGS.  5 A to  5 E  are screen display diagrams illustrating each operation screen displayed on the display unit  141  of the mobile information terminal  100  during the execution of the remote viewing function. 
       FIG.  5 A  is a screen display diagram illustrating an example of a basic screen  141   a  displayed on the display unit  141  of the mobile information terminal  100 . The basic screen  141   a  is displayed upon the power to the mobile information terminal  100  being turned on by pressing a power key  130   k   1  or upon a home key  130   k   2  being pressed during the execution of any application program. In the basic screen  141   a , icons associated with each application program executable by the mobile information terminal  100  are displayed on the display unit  141 . Selection of any one of the icons causes a predetermined application program associated with the selected icon to be executed. 
     Note that the icon may be selected through, for example, a tap operation on a predetermined area on the touch panel  130   t  that corresponds to a position on the display unit  141  at which the target icon is displayed. Alternatively, the icon may be selected with an operation key (not illustrated), such as a cross cursor key or an enter key. The icon may be selected on the basis of line-of-sight information obtained by the first image input unit  143  that detects the line-of-sight of the user of the mobile information terminal  100 . 
     In the mobile information terminal  100  that operates under the control of the basic operation execution module  1101 , selection of an icon  141   a   1  on the basic screen  141   a  through a user&#39;s operation such as a tap operation causes the basic operation execution module  1101  to invoke the remote viewing execution module  1102  and transfer main control to the remote viewing execution module  1102 . The transfer of the main control may be performed by, for example, an invocation of a program subroutine, and the basic operation execution module  1101  may operate in the background after the transfer of the main control. Note that the icon  141   a   1  is an icon associated with an application program that executes the remote viewing function on the mobile information terminal  100  of the present example. 
     An example of operations performed during the execution of the remote viewing function of the mobile information terminal  100  under the control of the remote viewing execution module  1102  will be described below with reference to the operation sequence in  FIG.  4   . 
     The selection of the icon  141   a   1  on the basic screen  141   a  through a user&#39;s operation such as a tap operation starts the remote viewing function of the mobile information terminal  100  (S 101 ). Next, the remote viewing execution module  1102  to which the main control has been transferred from the basic operation execution module  1101  by the invocation of the remote viewing function displays a program type selection screen  141   b  on the display unit  141 . 
       FIG.  5 B  is a screen display diagram illustrating an example of the program type selection screen  141   b  displayed on the display unit  141  of the mobile information terminal  100 . With the remote viewing function of the mobile information terminal  100  of the present example, it is possible to perform live viewing of a digital broadcast program received by the tuner/demodulator  431  of the broadcast receiver  400  and viewing of recorded content stored in the storage unit  410  by the broadcast receiver  400 . The program type selection screen  141   b  displays a selection icon  141   b   1  for performing the live viewing of a digital broadcast program and a selection icon  141   b   2  for performing the viewing of recorded content. In the following, a case where the live viewing of a digital broadcast program is performed will be described. 
     Selection of the icon  141   b   1  on the program type selection screen  141   b  through a user&#39;s operation such as a tap operation (S 102 ) causes the remote viewing execution module  1102  to first transmit, to the broadcast receiver  400  with which the mobile information terminal  100  is paired in advance, an operational state check request for checking an operational state of the broadcast receiver  400  (S 103 ). The pairing may be performed as appropriate through an authentication process in advance between the mobile information terminal  100  and the broadcast receiver  400  via a network constructed by the router  200   r  in a house in which the broadcast receiver  400  is installed. The mobile information terminal  100  stores the result of the authentication process in an authentication information storage area  1012  of the storage unit  110 . Note that the authentication process may be performed by any known technique. 
     The broadcast receiver  400  that has received the operational state check request from the mobile information terminal  100  checks an operational state of each component in the broadcast receiver  400  (S 104 ). That is, the broadcast receiver  400  checks the operational state of each of the hardware and software components to determine whether or not the remote viewing function is ready to be executed on the mobile information terminal  100 . The broadcast receiver  400  returns the result of the operational state check to the mobile information terminal  100 . 
     The remote viewing execution module  1102  of the mobile information terminal  100  obtains the result of the operational state check from the broadcast receiver  400  (S 105 ). The remote viewing execution module  1102  then refers to the obtained operational state of the broadcast receiver  400  to determine whether or not the remote viewing function is ready to be executed (S 106 ). When the broadcast receiver  400  is in use by another in-house user and particularly, for example, the function of the tuner  431  or the code converter  440  is not available, the remote viewing execution module  1102  determines that the remote viewing function is not ready to be executed. In S 105 , when, for example, the result of the operational state check cannot be obtained from the broadcast receiver  400 , the remote viewing execution module  1102  may also determine that the remote viewing function is not ready to be executed. When determining that the remote viewing function is not ready to be executed in S 106  (S 106 : NG), the remote viewing execution module  1102  returns the main control to the basic operation execution module  1101  and terminates its operation (S 118 ). 
     In contrast, when determining that the remote viewing function is ready to be executed in S 106  (S 106 : OK), the remote viewing execution module  1102  then transmits a program information transmission request to the broadcast receiver  400  (S 107 ). The broadcast receiver  400  that has received the program information transmission request from the mobile information terminal  100  returns the program information data row output from the demultiplexer  432  to the mobile information terminal  100  as program information. Upon obtaining the program information returned from the broadcast receiver  400  in response to the program information transmission request (S 108 ), the remote viewing execution module  1102  of the mobile information terminal  100  displays a program guide screen  141   c  created on the basis of the obtained program information on the display unit  141  (S 109 ). 
       FIG.  5 C  is a screen display diagram illustrating an example of the program guide screen  141   c  displayed on the display unit  141  of the mobile information terminal  100 . The program guide screen  141   c  is a table showing broadcast programs to be distributed in a digital broadcast service. The table is created by the remote viewing execution module  1102  on the basis of the program information obtained from the broadcast receiver  400 . In the present example, the program guide screen  141   c  shows detailed information on each broadcast program that is broadcast in each time slot on each channel, the information being arranged in a matrix in which the vertical axis represents time and the horizontal axis represents service ID (channel). 
     The program guide screen  141   c  may only show detailed information on broadcast programs that are currently being broadcast on respective channels. Furthermore, the program guide screen  141   c  may be displayed in such a way that only the broadcast programs that are currently being broadcast can be selected. Moreover, as an alternative to S 107  and S 108 , the remote viewing execution module  1102  of the mobile information terminal  100  may obtain the program information directly from a program information distribution server (not illustrated) on the Internet  200  via the mobile phone network communication unit  122 . 
     Next, a process of selecting a broadcast program that the user wishes to view is performed by using the remote viewing function (S 110 ). The process of selecting a broadcast program that the user wishes to view may be performed, on the program guide screen  141   c  displayed on the display unit  141  in S 109 , by detecting a tap operation on a predetermined area on the touch panel  130   t  corresponding to an area in which detailed information on the broadcast program that the user wishes to view is displayed (an area  141   c   1  in the example illustrated in  FIG.  5 C ) or the like. 
     After the process of selecting a broadcast program is performed in response to an operation by the user of the mobile information terminal  100 , the communication management execution module  1103  performs a process of checking a data communication state of the mobile information terminal  100  under the control of the remote viewing execution module  1102  (S 111 ). For example, in the process of checking a data communication state, a data communication amount check module  1103   a  of the communication management execution module  1103  performs a process of checking the total data communication amount of the mobile information terminal  100  through mobile phone network communication in a predetermined period. Furthermore, according to the result of the process of checking a data communication state, the remote viewing execution module  1102  displays, on the program guide screen  141   c , a remote image quality selection box  141   c   2  for prompting the user to select a viewing image quality of the broadcast program during remote viewing. 
       FIG.  5 D  is a screen display diagram illustrating an example of the remote image quality selection box  141   c   2  displayed on the program guide screen  141   c . For the mobile information terminal  100  of the present example, a viewing image quality during remote viewing can be selected from three types of viewing image qualities, namely, 720p, 360p, and 180p. In this configuration, three types of setting values, 720p, 360p, and 180p, are displayed in the remote image quality selection box  141   c   2  in such a way that the setting values are appropriately selectable. 
     The details of the above-described processes of checking the total data communication amount through mobile phone network communication in a predetermined period and displaying the remote image quality selection box  141   c   2  on the program guide screen  141   c  on the basis of the check result will be described later. 
     After the process of selecting a viewing image quality during remote viewing is performed in response to an operation by the user of the mobile information terminal  100  (S 112 ), the remote viewing execution module  1102  then transmits, to the broadcast receiver  400 , program identification information with which the broadcast program selected in S 110  can be identified and the setting value of the viewing image quality selected in S 112  (S 113 ). 
     After receiving the program identification information and the setting value of the viewing image quality from the mobile information terminal  100 , the broadcast receiver  400  controls the tuner/demodulator  431  on the basis of the received program identification information to select a channel for the broadcast program specified in the program identification information (S 114 ). Furthermore, the broadcast receiver  400  inputs a TS of the broadcast program output from the tuner/demodulator  431  to the code converter  440  via the demultiplexer  432 , and the code converter  440  performs a transcoding process that corresponds to the setting value of the received viewing image quality (S 115 ). That is, when the user of the mobile information terminal  100  selects 360p as a viewing image quality during remote viewing in S 112 , the code converter  440  transcodes 1080i video data of digital broadcast into the selected  360   p  video data, for example. The broadcast program data output from the code converter  440  is distributed to the mobile information terminal  100  via the LAN communication unit  421 . 
     The remote viewing execution module  1102  of the mobile information terminal  100  obtains the broadcast program data distributed from the broadcast receiver  400  in response to the transmission of the program identification information and the setting value of the viewing image quality (S 116 ). Furthermore, the content playback execution module  1104  performs, as appropriate, necessary processes such as decoding the obtained broadcast program data under the control of the remote viewing execution module  1102  and displays the broadcast program data as a remote viewing screen  141   d  on the display unit  141  via the image signal processor  142  (S 117 ). 
       FIG.  5 E  is a screen display diagram illustrating an example of the remote viewing screen  141   d  displayed on the display unit  141  of the mobile information terminal  100 . The remote viewing screen  141   d  is a viewing screen when live viewing of a digital broadcast program, which has been received by the in-house broadcast receiver  400 , is performed away from home on the mobile information terminal  100  via the Internet  200 . A control icon  141   d   1  is an icon for an operation such as terminating remote viewing or changing a channel. 
     When the remote viewing is stopped by a user&#39;s operation on the control icon  141   d   1  or when the broadcast program being viewed ends and the remote viewing stops automatically, the remote viewing execution module  1102  returns the main control to the basic operation execution module  1101  and terminates its operation (S 118 ). Note that the remote viewing execution module  1102  may continue its operation without termination thereof and display the program type selection screen  141   b  on the display unit  141  to prompt the user to select to perform the live viewing of a digital broadcast program again or the viewing of recorded content. This configuration only requires the operation to make a transition to S 102  of the operation sequence in  FIG.  4   . Alternatively, the remote viewing execution module  1102  may display the program guide screen  141   c  on the display unit  141  and prompt the user to select a broadcast program again. This configuration only requires the operation to make a transition to S 107  of the operation sequence in  FIG.  4   . 
     When the user selects, in S 102 , to perform the viewing of recorded content stored in the storage unit  410  of the broadcast receiver  400 , it is only required that a transmission request for recorded content list information be transmitted to the broadcast receiver  400  in S 107 . Furthermore, in S 108  and S 109 , it is only required that the recorded content list information transmitted from the broadcast receiver  400  be obtained and a recorded content list be created from the obtained recorded content list information and displayed on the display unit  141 . Moreover, in S 114 , it is only required that a process of reading predetermined recorded content from the storage unit  410  be performed on the basis of identification information on the recorded content transmitted from the mobile information terminal  100 . 
     Next, the processes of S 111  and S 112  will be described in detail. 
     Note that, with the limitation on communication speed imposed by the mobile phone carrier for the mobile information terminal  100  of the present example, the data communication speed is not limited (that is, for example, high-speed data communication of 75 Mbps is possible) while the total data communication amount in a month is less than or equal to 7.0 GB, and the data communication speed is limited to a lower speed (for example, less than or equal to 128 kbps) once the total data communication amount in the month exceeds 7.0 GB. Furthermore, on the mobile information terminal  100  of the present example, a viewing image quality during remote viewing (hereinafter referred to as a “remote viewing image quality”) can be selected from three types of remote viewing image qualities, 720p, 360p, and 180p as described above. Respective communication bands required for the remote viewing image qualities are about 4.0 Mbps, about 1.5 Mbps, and about 700 kbps. 
     These remote viewing image qualities may be used as viewing image qualities that can be transcoded by the code converter  440  of the broadcast receiver  400  and viewing image qualities which the mobile information terminal  100  supports. For example, the mobile information terminal  100  may obtain information relating to viewing image qualities that can be transcoded by the broadcast receiver  400  in S 105  and compare these viewing image qualities with viewing image qualities that can be displayed by the mobile information terminal  100 . The mobile information terminal  100  may obtain communication band information from the broadcast receiver  400  in S 105  because the value of the communication band corresponding to each remote viewing image quality depends on what is converted by the code converter  440 . 
     Selection of the 720p as a remote viewing image quality requires data transfer of about 1.47 GB to receive one-hour video data. That is, when the user selects the 720p as a remote viewing image quality, video data reception through high-speed data communication can be performed for only about 4.7 hours. When the user selects the 360p as a remote viewing image quality, to receive one-hour video data requires a data communication amount of about 0.55 GB, and the video data reception through high speed data communication can be performed for about 12.7 hours. When the user selects the 180p as a remote viewing image quality, to receive one-hour video data requires a data communication amount of about 0.27 GB, and the video data reception through high speed data communication can be performed for about 25.9 hours. 
       FIG.  6 A  is a schematic diagram illustrating an example of a process of controlling the remote viewing image quality according to the total data communication amount through mobile phone network communication in a predetermined period (in a month). 
     In the present example, two thresholds, namely, a first predetermined value (for example, 4.0 GB) and a second predetermined value (for example, 5.5 GB) are set for the total data communication amount (for example, 7.0 GB) up to which high-speed data communication is possible. The remote viewing image quality selectable by the user is controlled according to the result of comparing the data communication amount in a predetermined period (in a month) up to the time of viewing with the first predetermined value and the second predetermined value. Specifically, in S 111 , the data communication amount check module  1103   a  of the communication management execution module  1103  checks the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication in a predetermined period (in a month) up to the time of viewing (hereinafter referred to as a “particular point in time”). 
     (a) When the cumulative data communication amount is less than or equal to the first predetermined value, the remote viewing execution module  1102  performs the control in such a way that any one of the remote viewing image qualities of the 720p, 360p, and 180p can be selected in S 112 . (b) When the cumulative data communication amount is more than the first predetermined value and less than or equal to the second predetermined value, the remote viewing execution module  1102  performs the control in such a way that one of the remote viewing image qualities of the 360p and  180   p  can be selected in S 112 . (c) When the cumulative data communication amount is more than the second predetermined value, the remote viewing execution module  1102  performs the control in such a way that only the remote viewing image quality of the 180p can be selected in S 112 . 
     Basically, the particular point in time is the time of viewing, and particularly, the time when the viewing is started. However, the particular point in time may not be strictly limited to the time when the viewing is started because the viewing is started after the data communication amount is subjected to comparison and the remote viewing image quality is selected. The particular point in time may be, for example, the time of execution of S 111 , a certain time of the day when the cumulative data communication amount before the execution of S 111  is calculated, or a time of the day when the data communication amount up to the day before the execution of S 111  is totaled. 
     Note that the above-described process of checking the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication in a predetermined period (in a month) may be performed as follows: causing the data communication amount check module  1103  to transmit identification information with which the mobile information terminal  100  can be identified to the mobile phone communication server  300 ; and causing the mobile phone communication server  300  to obtain a value corresponding to the cumulative data communication amount of the mobile information terminal  100 . Alternatively, the process may be performed as follows: causing the basic operation execution module  1101  of the mobile information terminal  100  to operate in the background during data communication and to accumulate, in the storage unit  110  or the like, the data communication amount each time the data communication is performed through the mobile phone network communication unit  122 ; and causing the data communication amount check module  1103  to obtain the accumulation value, or other methods may be used. 
     Such a control makes it possible to reduce the likelihood of using up the data capacity within which high-speed data communication is possible due to successive selection of a higher remote viewing image quality when the remote viewing function is used and thereby making the subsequent use of service inconvenient. That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
     There may be a case where the above-described communication capacity within which high-speed data communication is possible in a predetermined period (in a month) differs among mobile phone carriers. In this case, control may be performed in such a way that the communication management execution module  1103  changes the first predetermined value and the second predetermined value depending on a mobile phone carrier to which a subscription has been made. Specifically, for example, (a) when the mobile information terminal  100  is used under the subscription to a mobile phone carrier A, the first predetermined value and the second predetermined value are set to 3.0 GB and 5.0 GB, respectively. (b) When the mobile information terminal  100  is used under the subscription to a mobile phone carrier B, the first predetermined value and the second predetermined value are set to 4.0 GB and 5.5 GB, respectively. (c) When the mobile information terminal  100  is used under the subscription to a mobile phone carrier C, the first predetermined value and the second predetermined value are set to 5.0 GB and 6.0 GB, respectively. 
     Note that the user may perform change control of the first predetermined value and the second predetermined value in, for example, a setting menu of the mobile information terminal  100  each time the mobile phone carrier to which the subscription has been made is changed. Alternatively, after the connection state of a subscriber identify module (SIM) card and the like (not illustrated) associated with the state of subscription to each mobile phone carrier is detected, the change control may be automatically performed according to the detected SIM card and the like. Each predetermined value used for the change control may be pre-stored in the mobile information terminal  100  as a reference table or may be obtained from the mobile phone communication server  300  or a database server (not illustrated) on a network each time the change control is performed. The change control may be performed according to each predetermined value stored in the SIM card and the like. This control may be performed by the communication management execution module  1103 . 
     Note that when the above-described communication capacity within which high-speed data communication is possible in a predetermined period (in a month) set by the mobile phone carrier is a sufficiently large amount or the mobile phone carrier does not impose a limitation on the communication speed, it goes without saying that the first predetermined value and the second predetermined value may not be set and all of the remote viewing image qualities may be made selectable. Furthermore, the number of predetermined values is not limited to two and one or more than two predetermined values may be set. 
     Such a control makes it possible to reduce the likelihood of using up the data capacity within which high-speed data communication is possible due to successive selection of a higher remote viewing image quality when the remote viewing function is used and thereby making the subsequent use of service inconvenient. That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
       FIG.  6 B  is a schematic diagram illustrating an example, which is different from the above example, of a process of controlling the remote viewing image quality according to the total data communication amount through mobile phone network communication in a predetermined period (in a month). In this example, the data communication amount management module  1103   a  of the communication management execution module  1103  checks the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication up to a particular point in time in a predetermined period (in a month) while the data communication period management module  1103   b  of the communication management execution module  1103  checks elapsed time up to the particular point in time in the predetermined period (in a month) in S 111 . According to these results, the remote viewing image quality selectable by the user is controlled. 
     That is, as illustrated in  FIG.  6 B , the communication management execution module  1103  checks elapsed time up to a particular point in time in the predetermined period (in a month), and (a) from the first day to the 10th day of each month, the first predetermined value and the second predetermined value are set to 3.0 GB and 5.0 GB, respectively. (b) From the 11th day to the 20th day, the first predetermined value and the second predetermined value are set to 4.0 GB and 5.5 GB, respectively. (c) From the 21st day to the end of the month, the first predetermined value and the second predetermined value are set to 5.0 GB and 6.0 GB, respectively. Note that the control may be performed using smaller units of time for the elapsed date and time. Furthermore, the elapsed time may be set by the user from, for example, a setting menu of the mobile information terminal  100  or may be obtained from the mobile phone communication server  300  or a database server (not illustrated). 
     Similar to the case where only the above-described control in  FIG.  6 A  is performed, such a control makes it possible to reduce the likelihood of using up the data capacity within which high-speed data communication is possible due to successive selection of a higher remote viewing image quality when the remote viewing function is used and thereby making the subsequent use of service inconvenient. Furthermore, the control makes it possible to distribute, in the predetermined period, the use of the data capacity within which high-speed data communication is possible. Moreover, the control makes it possible to reduce the likelihood of not using up, by the end of the predetermined period, the data capacity within which high-speed data communication is possible. Therefore, it becomes possible to efficiently use high-speed data communication according to the elapsed time in the predetermined period. That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
       FIG.  7 A  is a diagram illustrating an example of display format of the remote image quality selection box  141   c   2  displayed on the program guide screen  141   c . In this example, when the control described in  FIG.  6 A  is performed to prompt the user to select a remote viewing image quality, the display format of the remote image quality selection box  141   c   2  is controlled according to the result of comparing the data communication amount up to a particular point in time in a predetermined period (in a month), which has been checked by the data communication amount check module  1103   a  of the communication management execution module  1103 , with the first predetermined value and the second predetermined value. 
     Specifically, the data communication amount check module  1103   a  of the communication management execution module  1103  checks the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication up to a particular point in time in a predetermined period (in a month). (a) When the cumulative data communication amount is less than or equal to the first predetermined value, the remote image quality selection box  141   c   2  is displayed in a display format as illustrated in (a) of  FIG.  7 A . (b) When the cumulative data communication amount is more than the first predetermined value and is less than or equal to the second predetermined value, the remote image quality selection box  141   c   2  is displayed in a display format as illustrated in (b) of  FIG.  7 A . (c) When the cumulative data communication amount is more than the second predetermined value, the remote image quality selection box  141   c   2  is displayed in a display format as illustrated in (c) of  FIG.  7 A . 
     In the displays in  FIGS.  7 A and  7 B , circles at the left of remote viewing image quality values are so-called unselected radio buttons. The selection of a remote viewing image quality through a tap (click) operation on one of the radio buttons may be detected or the selection may be detected as a selection confirmed through an operation by the user after one of the radio buttons is tapped (clicked). Such a control allows the user, upon selecting a remote viewing image quality, to select only an appropriate remote viewing image quality corresponding to a data communication amount through mobile phone network communication up to a particular point in time in a predetermined period (in a month). That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
       FIG.  7 B  is a diagram illustrating an example, which is different from the above example, of display format of the remote image quality selection box  141   c   2  displayed on the program guide screen  141   c . In this example, when the user is prompted to select a remote viewing image quality under control partially changed from the control described in  FIG.  7 A , selectable remote viewing image qualities are not limited. Furthermore, the initial selection position of the remote image quality selection box  141   c   2  is controlled according to the result of comparing the data communication amount up to a particular point in time in a predetermined period (in a month), which is checked by the data communication amount check module  1103   a  of the communication management execution module  1103 , with the first predetermined value and the second predetermined value. 
     Specifically, the data communication amount check module  1103   a  of the communication management execution module  1103  checks the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication up to a particular point in time in a predetermined period (in a month). (a) When the cumulative data communication amount is less than or equal to the first predetermined value, the initial selection position is set to a remote viewing image quality of 720p among three selectable remote viewing image qualities, as illustrated in (a) of  FIG.  7 B . (b) When the cumulative data communication amount is more than the first predetermined value and is less than or equal to the second predetermined value, the initial selection position is set to a remote viewing image quality of 360p among three selectable remote viewing image qualities, as illustrated in (b) of  FIG.  7 B . (c) When the cumulative data communication amount is more than the second predetermined value, the initial selection position is set to a remote viewing image quality of 180p among three selectable remote viewing image qualities, as illustrated in (c) of  FIG.  7 B . 
     A black dot in a radio button at the left of a remote viewing image quality value in  FIG.  7 B  indicates an initial selection position. The black dot of the initial selection position can be moved when one of the radio buttons is tapped (clicked). Additionally, the selection may be confirmed by a certain user operation, and it may be detected that the confirmed remote viewing image quality at the right of the black dot, which includes the initial selection position, is selected. 
     Similar to the case where the above-described control in  FIG.  7 A  is performed, such a control allows the user, upon selecting a remote viewing image quality, to select only an appropriate remote viewing image quality corresponding to the total data communication amount through mobile phone network communication in a predetermined period (in a month). Furthermore, such a control allows the user to select any one of the remote viewing image qualities that can be selected by the remote viewing function of the mobile information terminal  100 . That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
     Note that when the control described in  FIG.  7 B  is performed and the user selects a remote viewing image quality that is higher than the remote viewing image quality of the initial selection position, a warning message or the like may be displayed on the display unit  141 . Specifically, for example, when the remote image quality selection box  141   c   2  is displayed in the display format illustrated in (b) of  FIG.  7 B  (in which the initial selection position is 360p) and the user selects 720p as a remote viewing image quality, a message such as “720p has been selected. Are you sure you want to perform remote viewing with this image quality?” is displayed on the display unit  141 . This makes it possible to prevent the data communication capacity from being wasted due to an operation error by the user or the like by confirming the user&#39;s intention again when the user selects a high remote viewing image quality that is not recommended by the mobile information terminal  100 . 
     Alternatively, control may be performed in such a way that the user is inhibited from selecting a remote viewing image quality and the remote viewing image quality is automatically determined according to the result of comparing the data communication amount up to a particular point in time in a predetermined period (in a month), which is checked by the data communication amount check module  1103   a  of the communication management execution module  1103 , with the first predetermined value and the second predetermined value. In this case, S 112  in  FIG.  4    is not needed. 
     Specifically, the data communication amount check module  1103   a  of the communication management execution module  1103  first checks the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication up to a particular point in time in a predetermined period (in a month). (a) When the cumulative data communication amount is less than or equal to the first predetermined value, the 720p is selected as a remote viewing image quality, and, in S 113  of the operation sequence in  FIG.  4   , the setting value corresponding to the selected remote viewing image quality is transmitted to the broadcast receiver  400 . (b) When the cumulative data communication amount is more than the first predetermined value and is less than or equal to the second predetermined value, the 360p is selected as a remote viewing image quality, and, in S 113  of the operation sequence in  FIG.  4   , the setting value corresponding to the selected remote viewing image quality is transmitted to the broadcast receiver  400 . (c) When the cumulative data communication amount is more than the second predetermined value, the 180p is selected as a remote viewing image quality, and, in S 113  of the operation sequence in  FIG.  4   , the setting value corresponding to the selected remote viewing image quality is transmitted to the broadcast receiver  400 . 
     During remote viewing that has been started, when the cumulative data communication amount up to a particular point in time in a predetermined period (in a month) exceeds one of the predetermined values, control may be performed in such a way that the remote viewing image quality is changed in the middle of the remote viewing. When the remote viewing image quality is changed, a message may be displayed on the display unit  141  indicating that the change has been completed. Alternatively, the remote viewing image quality may be changed after displaying a message for confirming the change on the display unit  141  and detecting a certain user operation. 
     Similar to the case where only the above-described control in  FIG.  6 A  is performed, such a control makes it possible to reduce the likelihood of using up the data capacity within which high-speed data communication is possible due to successive selection of a higher remote viewing image quality when the remote viewing function is used and thereby making the subsequent use of service inconvenient. Furthermore, such a control allows the user to omit selection of a remote viewing image quality. That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
       FIG.  8    is a screen display diagram illustrating a display example of a remote image quality selection box  141   c   3  displayed on the program guide screen  141   c , which is different from the display example of the remote image quality selection box  141   c   2  illustrated in  FIG.  5 D . The remote image quality selection box  141   c   3  is configured to control a remote viewing image quality that can be selected by a user so as to be displayed with remaining viewable times provided when each of the remote viewing image qualities is selected. 
     Note that the remaining viewable time can be calculated by dividing a remaining amount of high-speed data communication by a communication band value needed for each remote viewing image quality. The remaining amount of high-speed data communication is obtained as the difference between the cumulative data communication amount of the mobile information terminal  100  through mobile phone network communication up to a particular point in time in a predetermined period (in a month), and the total data communication amount up to which high-speed communication is possible for each predetermined period (for each month). Both the cumulative amount and the total amount are checked by the data communication amount check module  1103   a  of the communication management execution module  1103 . 
     The display of the remaining viewable time may be applied to the display illustrated in  FIG.  7 A  or may be applied to the display illustrated in  FIG.  7 B . Such a control allows the user to check, upon selecting a remote viewing image quality, the remaining viewable time within which high-speed data communication is possible. That is, it becomes possible to provide a mobile information terminal that provides high usability when content viewing is performed. 
     Note that in the above description, the example has been described in which the data transmission and reception between the mobile information terminal  100  and the Internet  200  is performed by the mobile phone network communication unit  122  via the mobile phone communication server  300  and the base station  300   b , and the data communication function provided by the mobile phone carrier, the mobile information terminal  100  being under the subscription thereof, has a capability to impose a limitation on communication speed. However, examples are not limited to the example described above. For example, in the case where the data transmission and reception between the mobile information terminal  100  and the Internet  200  is performed by the LAN communication unit  121  via the access point  200   a , the above-described control may be applied to data communication with a members-only content distribution server (not illustrated) or the like in which the total download capacity therefrom in each predetermined period (in each month) is limited. That is, the above-described control may be applied to both cases where a data communication channel has a limitation on the total data capacity thereof and where a server itself has a limitation on the total download capacity therefrom. 
     Some examples have been described above, but it goes without saying that configurations realizing the control described above are not limited to these examples and various modifications are contemplated. For example, some of the components may be replaced with other components, and numeric values, messages, and the like that appear in the descriptions or figures are merely examples. Thus, the use of different values, messages, and the like does not impair the effect. 
     The above-described functions and the like may be implemented as hardware by, for example, designing some or all of the functions and the like for an integrated circuit. Alternatively, the functions and the like may be implemented as software by using a microprocessor unit or the like interpreting and executing an operation program that realizes each of the functions and the like. The functions and the like may be implemented by using both hardware and software. 
     Note that the software that controls the mobile information terminal  100  may be pre-stored in, for example, the ROM  103  and/or the storage unit  110  of the mobile information terminal  100  before product shipment. The software may be obtained from the additional application server  500  or the like on the Internet  200  via the LAN communication unit  121  or the mobile phone network communication unit  122  after product shipment. Furthermore, the software stored in, for example, a memory card or optical disc may be obtained via the extended interface  124  or the like. 
     REFERENCE SIGNS LIST 
     
         
           100  Mobile information terminal 
           101  Main controller 
           102  System bus 
           103  ROM 
           104  RAM 
           110  Storage unit 
           120  Communication processor 
           124  Extended interface 
           130  Operation unit 
           140  Image processor 
           150  Audio processor 
           160  Sensor 
           200  Internet 
           200   a  Access point 
           200   r  Router 
           300  Mobile phone communication server 
           300   b  Base station 
           400  Broadcast receiver 
           400   a  Antenna 
           400   t  Broadcasting tower 
           500  Additional application server