Patent Publication Number: US-9432623-B2

Title: Communication terminal, display control method, and recording medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is based on and claims priority pursuant to 35 U.S.C. §119(a) to Japanese Patent Application Nos. 2014-193761 filed on Sep. 24, 2014, and 2015-183231, filed on Sep. 16, 2015, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present invention generally relates to controlling display of information through a communication terminal. 
     2. Description of the Related Art 
     An example of a communication system that transmits or receives content data between a plurality of communication terminals via a relay device includes a videoconference system that carries out videoconference via a communication network such as the Internet. There is an increasing need for such videoconference systems as the use of such systems contribute to reduction in business trip costs and time. In such a videoconference system, a plurality of videoconference terminals, which are examples of communication terminals, is used. A videoconference can be carried out by transmission or reception of image data and sound data between these videoconference terminals. 
     The same communication terminal (or of the same type) may be used for different applications or purposes. For example, in the case of using a communication terminal for remote diagnosis system, an image of the affected part of a patient needs to be sent to a remote place. It is thus preferable that image data be of high quality. In contrast, in the case of using a communication terminal for a videoconference system for merely conveying a message, image data may be of low quality. 
     The service provider thus offers various service plans to users, for example, by setting a service fee according to the level of communication quality in transmitting image data and/or sound data. The user can choose a specific service plan that can offer a sufficient level of communication quality with a reasonable charge fee to meet the user&#39;s need. 
     SUMMARY 
     Example embodiments of the present invention include a communication terminal, which controls a display to display a currently set value of quality parameter of content data to be transmitted from the communication terminal to a counterpart communication terminal, transmits a request for changing quality parameter from the currently set value to a value selected by a user to a communication management system through a network, receives an updated charge fee to be charged for transmitting content data having the selected value of quality parameter from the communication management system, and controls a display to display the updated charge fee. 
     Example embodiments of the present invention include a method of controlling display of information through a communication terminal, including: displaying a currently set value of quality parameter of content data to be transmitted from the communication terminal to a counterpart communication terminal; accepting a user input that requests to change quality parameter from the currently set value to a value selected by a user; receiving an updated charge fee to be charged for transmitting content data having the selected value of quality parameter from a communication management system in response to sending a request for changing the quality parameter; and displaying the updated charge fee. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       A more complete appreciation of the disclosure and many of the attendant advantages and features thereof can be readily obtained and understood from the following detailed description with reference to the accompanying drawings, wherein: 
         FIG. 1  is a schematic diagram illustrating a part of a communication system relating to videoconference communication, according to an example embodiment of the present invention; 
         FIG. 2  is a perspective view illustrating an outer appearance of a communication terminal of the communication system of  FIG. 1 ; 
         FIG. 3  is a schematic block diagram illustrating a hardware configuration of the communication terminal of  FIG. 2 ; 
         FIG. 4  is a schematic block diagram illustrating a hardware configuration of a communication management system of the communication system of  FIG. 1 ; 
         FIG. 5  is a schematic diagram illustrating the communication system of  FIG. 1 ; 
         FIG. 6  is a schematic block diagram illustrating a functional configuration of the communication system of  FIG. 1  according to an embodiment of the present invention; 
         FIG. 7  is an illustration of an example data structure of a service contents management table; 
         FIG. 8  is an illustration of an example data structure of an authentication management table; 
         FIG. 9  is an illustration of an example data structure of a terminal management table; 
         FIG. 10  is an illustration of an example data structure of a candidate list management table; 
         FIGS. 11A to 11D  ( FIG. 11 ) are an illustration of an example data structure of additional fee management tables; 
         FIG. 12  is an illustration of an example data structure of a service management table; 
         FIG. 13  is a data sequence diagram illustrating operation of processing a login request from the communication terminal, performed by the management system of  FIG. 1 , according to an embodiment of the present invention; 
         FIG. 14  is a data sequence diagram illustrating operation of obtaining image quality parameters and a charge fee each reflecting the change; 
         FIG. 15  is an illustration of an example communication quality configuration screen; 
         FIG. 16  is an illustration of an example communication quality configuration screen; 
         FIG. 17  is an illustration of an example communication quality configuration screen; 
         FIG. 18  is an illustration of an example communication quality configuration screen; 
         FIG. 19  is a data sequence diagram illustrating operation of preparing for starting communication, according to an embodiment of the present invention; and 
         FIG. 20  is a data sequence diagram illustrating operation of carrying out communication between the communication terminals, according to an embodiment of the present invention. 
     
    
    
     The accompanying drawings are intended to depict example embodiments of the present invention and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. 
     DETAILED DESCRIPTION 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     In describing example embodiments shown in the drawings, specific terminology is employed for the sake of clarity. However, the present disclosure is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner. 
     In the following description, illustrative embodiments will be described with reference to acts and symbolic representations of operations (e.g., in the form of flowcharts) that may be implemented as program modules or functional processes including routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types and may be implemented using existing hardware at existing network elements or control nodes. Such existing hardware may include one or more Central Processing Units (CPUs), digital signal processors (DSPs), application-specific-integrated-circuits, field programmable gate arrays (FPGAs) computers or the like. These terms in general may be referred to as processors. 
     Unless specifically stated otherwise, or as is apparent from the discussion, terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical, electronic quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     Referring to the drawings, an embodiment of the present invention is described. 
     &lt;Configuration of Videoconference System&gt; 
     Referring to  FIG. 1 , a communication system  1  for carrying out videoconference among a plurality of communication terminals ( 10   a ,  10   d ) is explained according to the embodiment.  FIG. 1  is a schematic diagram illustrating a portion of the communication system  1 , which relates to videoconference being carried out between the communication terminals  10   a  and  10   d.    
     The communication system  1  includes the plurality of communication terminals ( 10   a ,  10   d ), a relay device  30 , and a communication management system  50 . In the following, any arbitrary one or ones of the plurality of communication terminals ( 10   a ,  10   d ) is or are referred to as the communication terminal  10 . The communication terminal  10  transmits or receives image data and sound data as an example of content data. The image data may be a video image or a still image, or both of the video image and the still image. 
     In this disclosure, the communication terminal that sends a request for starting videoconference is referred to as the “starting terminal”, and the communication terminal serving as a request destination (relay destination) of videoconference is referred to as the “counterpart terminal”. In  FIG. 1 , the communication terminal  10   a  is referred to as the starting terminal, and the communication terminal  10   d  is referred to as the counterpart terminal. Alternatively, when the communication terminal  10   d  requests to start videoconference with the communication terminal  10   a , the communication terminal  10   d  is referred to as the starting terminal, and the communication terminal  10   a  is referred to as the counterpart terminal. Note that the communication terminal  10  may be used not only for communication between different offices or for communication between different rooms in the same office, but also for communication within the same room or for outdoor-indoor communication or outdoor-outdoor communication. In the case where the communication terminal  10  is used outside, wireless communication using a mobile phone communication network or the like is performed. 
     The relay device  30  relays content data among the plurality of communication terminals  10 . The communication management system  50  centrally controls login authentication of the communication terminal  10 , management of the communication state of the communication terminal  10 , management of a candidate list or the like, and management of the communication state or the like of the relay device  30 . 
     In the communication system  1 , a management data session “sei” is established between the starting terminal  10  and the counterpart terminal  10  via the communication management system  50  to transmit or receive various management data therebetween. Between the starting terminal  10  and the counterpart terminal  10 , four sessions are established via the relay device  30  to transmit or receive four items of data including high-resolution image data, intermediate-resolution image data, low-resolution image data, and sound data. In  FIG. 1 , these four sessions are collectively referred to as image and sound data session “sed”. The image and sound data session “sed” may not always include four sessions, but any number of sessions greater than or less than four. 
     Now, resolution of image data to be processed in this embodiment is described. The low-resolution image data serves as a base image and has horizontal 160 pixels by vertical 120 pixels. The intermediate-resolution image data has horizontal 320 pixels by vertical 240 pixels. The high-resolution image data has horizontal 640 pixels by vertical 480 pixels. In the case of a narrow band path, low-quality image data that only includes low-resolution image data serving as a base image is relayed. In the case of a relatively wide band path, intermediate-quality image data including low-resolution image data serving as a base image and intermediate-resolution image data is relayed. In addition, in the case of a very wide band path, high-quality image data including low-resolution image data serving as a base image, intermediate-resolution image data, and high-resolution image data is relayed. Since sound data is relatively small in data size, the sound data is relayed even in the case of a narrow band path. 
     Examples of the communication system  1  include a data providing system that performs one-way transmission of content data from one communication terminal to another communication terminal via a communication management system, and a communication system that intercommunicates information, information reflecting feelings, or the like between a plurality of communication terminals via a communication management system. The communication system is a system for intercommunicating information, information reflecting feelings, or the like between a plurality of communication terminals via a communication management system, and examples thereof include a teleconference system and a videoconference system. 
     In this embodiment, the communication system, the communication management system, and the communication terminal will be described while assuming a videoconference system serving as an example of the communication system, a videoconference management system serving as an example of the communication management system, and a videoconference terminal serving as an example of the communication terminal. That is, the communication terminal and the communication management system according to the embodiment of the present invention are applied not only to a videoconference system, but also to any desired communication system. 
     &lt;Hardware Configuration of Communication System&gt; 
     Now, a hardware configuration of the communication system  1  is described.  FIG. 2  is a perspective view illustrating an outer appearance of the communication terminal  10  of the communication system  1  of  FIG. 1 . As illustrated in  FIG. 2 , the communication terminal  10  includes a casing  1100 , an arm  1200 , and a camera housing  1300 . The casing  1100  has a front wall  1110  provided with an inlet face including a plurality of inlet holes, and a back wall  1120  having an exhaust face  1121  on which a plurality of exhaust holes is formed. As a cooling fan included in the casing  1100  is driven, air behind the communication terminal  10  can be taken in via the inlet face and exhausted to the rear of the communication terminal  10  via the exhaust face  1121 . A right-side wall  1130  of the casing  1100  has a sound pickup hole  1131  formed thereon, and a built-in microphone  114 , described later, is capable of picking up sound such as sound, noise, or vibration. 
     An operation panel  1150  is formed toward the right-side wall  1130  of the casing  1100 . The operation panel  1150  has a plurality of operation keys ( 108   a  to  108   e ) described later, a power switch  109  described later, and an alarm lamp  119  described later, which are formed thereon. The operation panel  1150  further has a sound output face  1151  formed thereon, which is formed of a plurality of sound output holes for allowing output sound from a built-in speaker  115  described later to pass through. In addition, an accommodation portion  1160  serving as a recess for accommodating the arm  1200  and the camera housing  1300  is formed toward a left-side wall  1140  of the casing  1100 . A plurality of connection ports ( 1132   a  to  1132   c ) for electrically connecting cables to an external device connection interface (I/F)  118  described later is provided on the right-side wall  1130  of the casing  1100 . In contrast, a connection port for electrically connecting a cable  120   c  for a display  120  to the external device connection I/F  118  described later is provided toward the left-side wall  1140  of the casing  1100 . 
     The following description uses the term “operation key(s)  108 ” for indicating an arbitrary one or ones of the operation keys ( 108   a  to  108   e ), and the term “connection port(s)  1132 ” for indicating an arbitrary one or ones of the connection ports ( 1132   a  to  1132   c ). 
     The arm  1200  is attached to the casing  1100  via a torque hinge  1210  so as to be rotatable in the vertical direction within the range of a tilt angle θ 1  of 135 degrees with respect to the casing  1100 .  FIG. 2  illustrates a state in which the tilt angle θ 1  is 90 degrees. The camera housing  1300  has a built-in camera  112  provided thereon, which will be described later, and the camera  112  can capture an image of a user, a document, a room, or the like. The camera housing  1300  is formed with a torque hinge  1310 . With the torque hinge, the camera housing  1300  is attached to the arm  1200 . The camera housing  1300  is made rotatable in the vertical and horizontal directions within the range of a pan angle θ 2  of ±180 degrees and a tilt angle θ 3  of ±45 degrees with respect to the arm  1200 , in which the state illustrated in  FIG. 2  serves as 0 degrees. 
     Note that the external view illustrated in  FIG. 2  is only exemplary and the appearance is not restricted thereto. The camera  112  and the microphone  114  need not necessarily be built-in devices and may be external devices. Since the communication management system  50  has the same appearance as that of a general server computer, a description of the appearance thereof is omitted. 
       FIG. 3  is a schematic block diagram illustrating a hardware configuration of the communication terminal  10 . As illustrated in  FIG. 3 , the communication terminal  10  of the embodiment includes a central processing unit (CPU)  101  that controls entire operation of the communication terminal  10 , a read only memory (ROM)  102  that stores a program for operating the CPU  101  such as an initial program loader (IPL), a random access memory (RAM)  103  that operates as a work area for the CPU  101 , a flash memory  104  that stores various types of data, such as the terminal control program, image data, and sound data, a solid state drive (SSD)  105  that controls reading/writing of various types of data from/to the flash memory  104  under control of the CPU  101 , a medium I/F  107  that controls reading/writing (storage) of data from/to a recording medium  106 , the operation key  108  operated in the case of for example, selecting a counterpart terminal of the communication terminal  10 , the power switch  109  for turning on/off the power of the communication terminal  10 , and a network interface (I/F)  111  for transmitting data using the communication network  2 . In alternative to the SSD, a hard disk drive (HDD) may be used. 
     In addition, the communication terminal  10  includes the built-in camera  112 , which captures an image of a subject and obtains image data under control of the CPU  101 , an imaging element I/F  113  that controls driving of the camera  112 , the built-in microphone  114 , which receives a sound input, the built-in speaker  115 , which outputs sounds, a sound input/output I/F  116  that processes inputting/outputting of a sound signal between the microphone  114  and the speaker  115  under control of the CPU  101 , a display I/F  117  that transmits image data to an external display  120  under control of the CPU  101 , the external device connection I/F  118  for connecting various external devices, and a bus line  110  such as an address bus and a data bus for electrically connecting the above-described elements as illustrated in  FIG. 3 . 
     The display  120  is a display formed of liquid crystal or organic electroluminescence (EL) that displays an image of a subject, an operation icon, or the like. In addition, the display  120  is connected to the display I/F  117  by the cable  120   c . The cable  120   c  may be an analog red green blue (RGB) (video graphic array (VGA)) signal cable, a component video cable, a high-definition multimedia interface (HDMI) signal cable, or a digital video interactive (DVI) signal cable. 
     The camera  112  includes a lens and a solid-state imaging element that converts an image (video) of a subject to electronic data by converting light to electric charge. As the solid-state imaging element, for example, a complementary metal-oxide-semiconductor (CMOS) or a charge-coupled device (CCD) is used. 
     The external device connection I/F  118  is capable of connecting an external device such as an external camera, an external microphone, or an external speaker by using a Universal Serial Bus (USB) cable or the like. In the case where an external camera is connected, the external camera is driven in preference to the built-in camera  112  under control of the CPU  101 . Similarly, in the case where an external microphone is connected or an external speaker is connected, the external microphone or the external speaker is driven in preference to the built-in microphone  114  or the built-in speaker  115  under control of the CPU  101 . 
     The recording medium  106  is removable from the communication terminal  10 . In addition, a non-volatile memory that reads or writes data under control of the CPU  101  is not limited to the flash memory  104 , and an electrically erasable and programmable read-only memory (EEPROM) may be used instead. Further, the terminal control program may be recorded in a file in a format installable or executable on a computer-readable recording medium such as the recording medium  106  for distribution In addition, the terminal control program may be stored on the ROM  102 , instead of the flash memory  104 . 
       FIG. 4  is a diagram illustrating a hardware configuration of the communication management system  50  according to the embodiment. The communication management system  50  includes a CPU  201  that controls entire operation of the communication management system  50 , a ROM  202  that stores a program for operating the CPU  201 , such as an IPL, a RAM  203  used as a work area for the CPU  201 , the HD  204 , which stores various types of data, such as the communication management program, a hard disk drive (HDD)  205  that controls reading/writing of various types of data from/to the HD  204  under control of the CPU  201 , a medium I/F  207  that controls reading/writing (storage) of data from/to a recording medium  206  such as a flash memory, a display  208  that displays various types of information such as a cursor, a menu, a window, characters, or an image, a network I/F  209  for transmitting data using the communication network  2 , a keyboard  211  including a plurality of keys for entering characters, numerals, and various instructions, a mouse  212  that selects and executes various instructions, selects a processing target, and moves the cursor, a compact disc read-only memory (CD-ROM) drive  214  that controls reading/writing of various types of data from/to a CD-ROM  213  serving as an example of a removable recording medium, and a bus line  210  such as an address bus and a data bus for electrically connecting the above-described elements, as illustrated in  FIG. 6 . 
     Note that the communication management program may be recorded in a file in a format installable or executable on a computer-readable recording medium such as the recording medium  206  or the CD-ROM  213  for distribution. In addition, the communication management program may be stored on the ROM  202 , instead of the HD  204 . 
     Other examples of the removable recording medium include a computer-readable recording medium such as a compact disc recordable (CD-R), a digital versatile disk (DVD), and a Blue-ray disk. 
     Since the relay device  30  has a hardware configuration that is the same as or similar to that of the above-described communication management system  50 , descriptions thereof are omitted. In case of the relay device  30 , the HD  204  stores a relay device control program in alternative to the communication management program. 
     &lt;Configuration of Communication System&gt; 
     Referring now to  FIG. 5 , a configuration of the communication system  1  is explained according to the embodiment.  FIG. 5  is a schematic diagram illustrating the communication system  1  of  FIG. 1 . 
     In  FIG. 5 , the starting terminal  10   a , the counterpart terminal  10   d , the relay device  30 , and the communication management system  50  are connected to the communication network  2  including the Internet. The communication network  2  may include wireless network, in addition to wired network. The communication terminal  10   a  is operated by a user C 1 , and the communication terminal  10   d  is operated by a user C 2 . The communication management system  50  provides the communication terminal  10  with various services as described below. 
     &lt;Functional Configuration of Communication System&gt; 
     Referring now to  FIGS. 3, 4, and 6 , a functional configuration of the communication system  1  of  FIG. 1  is described according to an embodiment of the present invention.  FIG. 6  is a schematic block diagram illustrating a functional configuration of the communication system  1  of  FIG. 1  according to the embodiment of the present invention. 
     &lt;Functional Configuration of Terminal&gt; 
     The terminal  10  includes a transmitter/receiver  11 , an acceptor  12 , a communication control  13 , a display control  17 , and a data processor  19 . These units are functions that are implemented by operating any of the elements illustrated in  FIG. 3  in cooperation with the instructions of the CPU  101  according to the terminal control program expanded from the flash memory  104  to the RAM  103 . The terminal  10  further includes a memory  1000  configured by the RAM  103  illustrated in  FIG. 3  or the flash memory  104  illustrated in  FIG. 3 . The terminal  10  is inserted with a recording medium  1010 , which may be implemented by the recording medium  106  illustrated in  FIG. 3 . The data processor  19  reads or writes various data from or to the recording medium  1010 . 
     Referring to  FIGS. 3 and 6 , a functional configuration of the terminal  10  is explained in detail. In the following description of functional configuration of the terminal  10 , relationships of the elements in  FIG. 3  with the functional configuration of the terminal  10  in  FIG. 6  will also be described. 
     The transmitter/receiver  11  of the terminal  10  illustrated in  FIG. 6 , which may be implemented by the instructions of the CPU  101  of  FIG. 3 , and the network I/F  111  of  FIG. 3  transmits or receives various data (or information) to the other terminal, device, or system through the communication network  2 . Before starting communication with a desired counterpart terminal, the transmitter/receiver  11  starts receiving state information indicating the state of each candidate counterpart terminal, from the management system  50 . The state information not only indicates the operating state of each terminal  10  (whether the terminal  10  is online or offline), but also indicates a detailed state such as whether the terminal  10  whose state is online is now capable of communicating or is currently communicating, or the user of the terminal  10  is not at the terminal  10 . In addition, the state information not only indicates the operating state of each terminal  10 , but also indicates various states, such as the state that the cable  120   c  is disconnected from the terminal  10 , the state that the terminal  10  can output sounds but not images, or the state that the terminal  10  is muted. Hereinafter, the case in which the state information indicates the operating state will be described by way of example. 
     The acceptor  12 , which is implemented by the instructions of the CPU  101  illustrated in  FIG. 3  and by the operation keys  108  and the power switch  109  illustrated in  FIG. 3 , accepts various inputs from the user. For example, when the user turns on the power switch  109  illustrated in  FIG. 3 , the acceptor  12  illustrated in  FIG. 6  accepts the power on operation and turns on the power. 
     The communication control  13  is implemented by the instructions of the CPU  101 , and any desired device relating to input or output of content data. In one example, the communication control  13  is implemented by the instructions of the CPU  101  illustrated in  FIG. 3  and by the camera  112  and the imaging element I/F  113  illustrated in  FIG. 3 . The communication control  13  captures an image of a subject and outputs image data obtained by capturing the image. In one example, the communication control  13  is implemented by the instructions of the CPU  101  illustrated in  FIG. 3  and by the sound input/output I/F  116  illustrated in  FIG. 3 . After the sound of the user is converted to a sound signal by the microphone  114 , the communication control  13  receives sound data according to this sound signal. In another example, the communication control  13  is implemented by the instructions of the CPU  101  illustrated in  FIG. 3  and by the sound input/output I/F  116  illustrated in  FIG. 3 , and outputs the sound signal according to the sound data to the speaker  115 , and the speaker  115  outputs sound. The display control  17  is implemented by the instructions of the CPU  101  illustrated in  FIG. 3  and by the display I/F  117  illustrated in  FIG. 3 . 
     The display control  17  combines images of different resolutions and transmits the combined image to the display  120 . The display control  17  also transmits information on a candidate list, received from the management system  50 , to the display  120 , and controls display of the candidate list on the display  120 . The display control  17  of the terminal  10  causes the display  120  to display a screen such as a communication quality configuration screen. 
     The data processor  19 , which may be implemented by the instructions of the CPU  101  illustrated in  FIG. 3  and by the SSD  105  illustrated in  FIG. 3 , or by the instructions of the CPU  101 , performs processing to store various types of data in the memory  1000  or the recording medium  1010  or to read various types of data stored in the memory  1000  or the recording medium  1010 . The memory  1000  stores a terminal identification (ID) for identifying the terminal  10 , a password, and the like. Further, every time image data and sound data are received in performing communication with a counterpart terminal, the memory  1000  overwrites the image data and sound data. The display  120  displays an image based on image data before being overwritten, and the speaker  115  outputs sound based on sound data before being overwritten. 
     Note that a terminal ID in the embodiment is an example of identification information that is used to uniquely identify a specific terminal  10 , such that a language, a character(s), a symbol(s), or various marks are not limited to the above-described embodiment. For example, a combination of at least two of the above-mentioned language, character(s), symbol(s), and various marks may be used as a terminal ID. Instead of a terminal ID, a user ID for identifying the user at the terminal  10  may be used. In such case, terminal identification information includes not only the terminal ID, but also the user ID. 
     &lt;Functional Configuration of Relay Device&gt; 
     The relay device  30  includes a transmitter/receiver  31 , a determiner  32 , a changer  33 , and a data processor  39 . These units are functions that are implemented by or that are caused to function by operating any of the elements illustrated in  FIG. 4  in cooperation with the instructions of the CPU  201  according to the relay device control program expanded from the HD  204  to the RAM  203 . The relay device  30  also includes a memory  3000  configured by the RANI  203  illustrated in  FIG. 4  and/or the HD  204  illustrated in  FIG. 4 . 
     (Service Contents Management Table) 
     The memory  3000  stores a service contents management database (DB)  3001  configured by a service contents management table such as that illustrated in  FIG. 7 . The service contents management table of  FIG. 7  stores, for each session to be used for communication among the plurality of terminals  10 , a session ID for identifying the session, service contents, and IP addresses of the terminals  10  that are communicating through that session in association with one another. As an example of service contents, various quality parameters for controlling operation of the relay device  30  in relaying content data are stored as illustrated in  FIG. 7 . In this embodiment illustrated in  FIG. 7 , the quality parameters include an image frame rate (frame per second), an image resolution, and a maximum data transfer speed (mega kilobits per second). More specifically, the quality parameters used in this embodiment are those parameters that affect quality of content data to be received at the terminal  10 . As described above, the content data in this embodiment may be image data and/or sound data. The service contents may additionally or alternatively include any other information such as a sampling rate of sound, color depth of image, or encoding format, as the quality parameters affecting the quality of content data. The relay device  30  refers to the service contents management table of  FIG. 7  to change, if needed, quality of content data (image data and/or sound data) received from the terminal  10 , such that the content data to be transmitted to the counterpart terminal  10  has the quality parameters as defined by the service contents management table of  FIG. 7  for a specific session. 
     (Functional Configuration of Relay Device) 
     Next, functional configuration of the relay device  30  will be described in detail. In the following description of functional configuration of the relay device  30 , relationships of the elements in  FIG. 4  with the functional configuration of the relay device  30  in  FIG. 6  will also be described. 
     The transmitter/receiver  31  of the relay device  30  illustrated in  FIG. 6 , which is implemented by the instructions of the CPU  201  illustrated in  FIG. 4  and by the network I/F  209  illustrated in  FIG. 4 , transmits or receives various types of data (or information) to or from another terminal, device, or system via the communication network  2 . The transmitter/receiver  31  also serves as a transferer, which transfers content data transmitted from one terminal  10  to another terminal  10 . 
     The determiner  32 , which may be implemented by the instructions of the CPU  201  of  FIG. 4 , determines whether quality of content data (image data and/or sound data) transmitted from the terminal  10  through a specific session does not exceed the quality as defined by the quality parameters in the table of  FIG. 7  for that session. 
     The changer  33 , which may be implemented by the instructions of the CPU  201  of  FIG. 4 , changes quality parameters of content data (image data and/or sound data), which are to be transmitted from one terminal to another terminal, when the determiner  32  determines that the quality of content data exceeds the quality in the service contents management table ( FIG. 7 ). 
     The data processor  39 , which may be implemented by the instructions of the CPU  201  illustrated in  FIG. 4  and the HDD  205  illustrated in  FIG. 4 , performs processing to store various types of data in the memory  3000  or read various types of data stored in the memory  3000 . 
     &lt;Functional Configuration of Management System&gt; 
     The management system  50  includes a transmitter/receiver  51 , a manager  53 , a generator  54 , a calculator  55 , and a data processor  59 . These units are functions that are implemented by or that are caused to function by operating any of the elements illustrated in  FIG. 4  in cooperation with the instructions of the CPU  201  according to the communication management program expanded from the HD  204  to the RAM  203 . In addition, the management system  50  includes a memory  5000  configured by the HD  204  illustrated in  FIG. 4 . 
     (Authentication Management Table) 
     The memory  5000  stores an authentication management DB  5001  configured by the authentication management table illustrated in  FIG. 8 . In the authentication management table, for each one of the terminals  10  managed by the management system  50 , the terminal ID and the password are stored in association with each other. For example, the authentication management table illustrated in  FIG. 8  indicates that the terminal ID of the terminal  10   aa  is “ 01   aa ”, and the password of the terminal  10   aa  is “aaaa”. 
     (Terminal Management Table) 
     The memory  5000  also stores a terminal management DB  5002  configured by a terminal management table such as that illustrated in  FIG. 9 . The terminal management table stores, for each one of the terminals  10  managed by the management system  50 , the terminal ID of the terminal  10 , a counterpart terminal name in the case where the terminal  10  serves as a counterpart terminal, the operating state of the terminal  10 , a date/time received at which login request information described later is received at the management system  50 , and the IP address of the terminal  10 , in association with one another. For example, the terminal management table illustrated in  FIG. 9  indicates that the terminal  10   aa  with the terminal ID “ 01   aa ” has the counterpart terminal name “AA terminal, Tokyo office, Japan”, the operating state “online (communication OK)”, the date/time received at which login request information is received by the management system  50  “Apr. 10, 2014, 13:40”, and the IP address 1.2.1.3″. 
     (Candidate List Management Table) 
     The memory  5000  further stores a candidate list management DB  5003  configured by a candidate list management table such as that illustrated in  FIG. 10 . The candidate list management table stores, for each one of the terminals  10  managed by the management system  50 , the terminal ID of the terminal  10  (starting terminal) that requests to start communication, in association with the terminal IDs of all counterpart terminals  10  registered as candidate counterpart terminals for the terminal  10 . For example, the candidate list management table illustrated in  FIG. 10  indicates that candidates for a counterpart terminal to which a starting terminal (terminal  10   aa ) whose terminal ID is “ 01   aa ” can send a request to start communication in a videoconference are the terminal  10   ab  whose terminal ID is “ 01   ab ”, the terminal  10   ba  whose terminal ID is “ 01   ba ”, the terminal  10   bb  whose terminal ID is “ 01   bb ”, and so forth. The candidate counterpart terminals are updated by addition or deletion in response to an addition or deletion request received from an arbitrary terminal to the management system  50 . 
     (Additional Fee Management Table) 
     The memory  5000  stores an additional fee management DB  5004 , which may be implemented by a plurality of additional fee management tables of  FIGS. 11A to 11D . While this embodiment has a plurality of additional fee management tables, only one additional fee management table may be managed. The additional fee management tables are previously prepared for each of quality parameters managed by the service contents management table of  FIG. 7 . The table of  FIG. 11A  stores information regarding the additional fee to be charged as the frame rate increases. The table of  FIG. 11B  stores information regarding the additional fee to be charged according to a value of the resolution. The table of  FIG. 11C  stores information regarding the additional fee to be charged according to a value of the maximum data transmission rate. The table of  FIG. 11D  stores information regarding the additional fee to be charged according to a value of the sound quality level. In this embodiment, the additional charge fees that are calculated for the service quality parameters of  FIG. 7  using the tables of  FIG. 11  are added to the basic charge fee (50 yen/min) to obtain the total charge fee. 
     (Service Management Table) 
     The memory  5000  further stores a service management DB  5005 , such as the service management table of  FIG. 12 . The service management table of  FIG. 12  stores, for each terminal  10  managed by the management system  50 , the terminal ID, the service contents, and the charge fee in association with one another. Since the service contents (frame rate, resolution, maximum data transmission rate, and sound quality) of  FIG. 12  are the same as those managed by the service contents management table of  FIG. 7 , explanation thereof is omitted. In this example, however, the quality parameters of  FIG. 12  indicate the quality of content data used in providing the service to a specific user at the terminal  10 . More specifically, the quality parameters of content data differ among the users depending on the service plan of each user. In this embodiment, information indicating the quality parameters of content data is previously stored for each terminal  10  operated by the user, in association with the terminal ID of the terminal  10 . The charge fee indicates an amount of fee to be paid by the user of the terminal  10  identified with a specific terminal ID, to a service provider providing the service to the user. The service provider may be an administrator of the management system  50  or a user of the management system  50 . The user in this embodiment may be an individual user or a group of users, for example, who belong to the same organization. 
     In this embodiment, information in the service management table of  FIG. 12 , such as the quality parameters and the charge fee, is previously set by the service provider for each terminal  10  operated by a specific user. The management system  50  transmits information obtained from the service management table of  FIG. 12 , to the relay device  30 , for example, when requesting to establish a session. Accordingly, the service contents management table of  FIG. 7  may be updated to reflect any change in the service management table of  FIG. 12 , as information to be stored in the service contents management table of  FIG. 7  is transmitted from the management system  50 . 
     (Functional Configuration of Management System) 
     Next, referring to  FIGS. 4 and 6 , functional configuration of the management system  50  will be described in detail. In the following description of functional configuration of the management system  50 , relationships of the elements in  FIG. 4  with functional configuration of the management system  50  in  FIG. 6  will also be described. 
     The transmitter/receiver  51 , which is implemented by the instructions of the CPU  201  illustrated in  FIG. 4  and by the network IN  209  illustrated in  FIG. 4 , transmits or receives various types of data (or information) to or from another terminal, device, or system via the communication network  2 . 
     The manager  53 , which may be implemented by the instructions of the CPU  201  of  FIG. 4 , updates a record for a specific terminal ID in the service management table ( FIG. 12 ) through the data processor  59 , to reflect the quality parameters and the charge fee if such information have been changed. 
     The generator  54 , which may be implemented by the instructions of the CPU  201  of  FIG. 4 , converts high-quality content data (image data and/or sound data) read out by the data processor  59  from the memory  5000 , so as to match the quality parameters as defined in the service management table ( FIG. 12 ), to generate sample data. In this embodiment, it is assumed that the memory  5000  previously stores any content data, such as image data and sound data, as sample data. 
     The calculator  55 , which may be implemented by the instructions of the CPU  201  of  FIG. 4 , adds the additional fee to the current charge fee, which is determined by the current service plan, to calculate a new charge fee reflecting the change. 
     The data processor  59 , which may be implemented by the instructions of the CPU  201  illustrated in  FIG. 4  and the HDD  205  illustrated in  FIG. 4 , performs processing to store various types of data in the memory  5000  or read various types of data stored in the memory  5000 . 
     &lt;Operation&gt; 
     Referring to  FIGS. 13 to 20 , operation performed by the communication system  1  is explained according to an embodiment of the present invention. Referring to  FIG. 13 , operation of processing a login request received from the terminal  10   aa  is explained.  FIG. 13  is a data sequence diagram illustrating operation of processing the login request received from the terminal  10   aa , according to an embodiment of the present invention. In  FIG. 13 , various management data is transmitted or received through the management data session “sei” in  FIG. 1 . 
     When the user of the starting terminal (terminal  10   aa ) turns on the power switch  109  illustrated in  FIG. 2 , the acceptor  12  illustrated in  FIG. 6  accepts the power on operation and turns on the power (S 21 ). In response to acceptance of the power on operation, the transmitter/receiver  11  automatically transmits login request information indicating a login request to the management system  50  via the communication network  2  (S 22 ). Note that the login request information may be transmitted in response to operation of the operation keys  108  by the user, instead of turning on of the power switch  109 . The login request information includes a terminal ID for identifying the terminal  10   aa , which is a local terminal serving as a starting terminal, and a password. The terminal ID and the password are data that have been read via the data processor  19  from the memory  1000  and sent to the data transmitter/receiver  11 . Alternatively, the terminal ID and the password may be recorded on the recording medium  1010  and may be read out from the recording medium  1010 . In the case of transmitting login request information from the terminal  10   aa  to the management system  50 , the management system  50 , which is a receiving side, receives the IP address of the terminal  10   aa , which is a transmitting side. 
     Next, the data processor  59  of the management system  50  performs terminal authentication by searching the authentication management table of  FIG. 8  using the terminal ID and the password included in the login request information received via the data transmitter/receiver  51  as search keys, and determining whether the same terminal ID and the same password are managed in the authentication management table of  FIG. 8  (S 23 ). In the case where the data processor  59  determines that the login request is a login request received from a terminal  10  that has a legitimate use authority since the same terminal ID and the same password are managed, the data processor  59  stores, in the terminal management table of  FIG. 9 , the terminal ID of the terminal  10   aa , the operating state, the date/time received at which the above-described login request information is received, and the IP address of the terminal  10   aa  in association with one another (S 24 ). Accordingly, the operating state “Online (Communication OK)”, the date/time received “4.10.2014.13:40”, and the IP address “1.2.1.3” of the terminal  10   aa  are managed in association with the terminal ID “ 01   aa ” in the terminal management table illustrated in  FIG. 9 . 
     The data transmitter/receiver  51  of the management system  50  transmits authentication result information indicating an authentication result to the starting terminal (terminal  10   aa ) which has sent the login request, via the communication network  2  (S 25 ). In the embodiment, the case in which it has been determined that the terminal  10   aa  is a terminal that has a legitimate use authority will be described as follows. 
     The data processor  59  of the management system  50  searches the candidate list management table of  FIG. 10  using the terminal ID “ 01   aa ” of the starting terminal  10   aa  which has sent the login request as a search key, and reads out to extract the terminal ID of a candidate counterpart terminal that can communicate with the starting terminal  10   aa  (S 26 ). For the descriptive purposes, it is assumed that the candidates of counterpart terminals  10  for the starting terminal  10   aa  are the terminals  10   ab ,  10   ba , and  10   db.    
     Next, the data processor  59  searches the terminal management table of  FIG. 9  using the extracted terminal IDs (“ 01   ab ”, “ 01   ba ”, “ 01   db ”) of the candidate counterpart terminals, as search keys, to obtain the operating states (“Offline”, “Online”, and “Online”) of the terminals ( 10   ab ,  10   ba , and  10   db ) (S 27 ). 
     Next, the transmitter/receiver  51  transmits counterpart terminal state information including the terminal IDs (“ 01   ab ”, “ 01   ba ”, and “ 01   db ”) serving as the search keys used at S 27  described above and the operating states (“Offline”, “Online (Communication OK)”, and “Online (Communication OK)”) of the counterpart terminals (terminals  10   ab ,  10   ba , and  10   db ) corresponding to these terminal IDs to the starting terminal  10   aa  via the communication network  2  (S 28 ). The starting terminal  10   aa  can obtain the current operating states (“Offline”, “Online (Communication OK)”, and “Online (Communication OK)”) of the terminals ( 10   ab ,  10   ba , and  10   db ) that are candidates of a counterpart terminal that can communicate with the starting terminal  10   aa.    
     The data processor  59  of the management system  50  further searches the candidate list management table of  FIG. 10  using the terminal ID “ 01   aa ” of the starting terminal  10   aa  which has sent the login request as a search key, to extract the terminal ID of another starting terminal that registers the terminal ID “ 01   aa ” of the starting terminal  10   aa  as a candidate counterpart terminal (S 29 ). In the candidate list management table illustrated in  FIG. 10 , the terminal IDs of other starting terminals that are extracted are “ 01   ab ”, “ 01   ba ”, and “ 01   db”.    
     Next, the data processor  59  of the management system  50  searches the terminal management table of  FIG. 9  using the terminal ID “ 01   aa ” of the starting terminal  10   aa  which has sent the login request as a search key, and obtains the operating state of the starting terminal  10   aa  (S 30 ). 
     The transmitter/receiver  51  transmits counterpart terminal state information including the terminal ID “ 01   aa ” and the operating state “Online (Communication OK)” of the starting terminal  10   aa , obtained at S 30 , to terminals ( 10   ba  and  10   db ) whose operating states are “Online (Communication OK)” in the terminal management table ( FIG. 9 ), among the terminals ( 10   ab ,  10   ba , and  10   db ) having to the terminal IDs (“ 01   ab ”, “ 01   ba ”, and “ 01  db”) extracted at S 29  (S 31 - 1  and S 31 - 2 ). When transmitting the counterpart terminal state information to the terminals ( 10   ba  and  10   db ), the transmitter/receiver  51  refers to the IP addresses of the terminals, which are managed in the terminal management table illustrated in  FIG. 9 , using the terminal IDs (“ 01   ba ” and “ 01   db ”). Accordingly, the terminal ID “ 01   aa ” and the operating state “online” of the starting terminal (terminal  10   aa ) which has sent the login request can be transmitted to other counterpart terminals (terminals  10   ba  and  10   db ) that can communicate with the starting terminal (terminal  10   aa ). 
     For any other terminal  10 , as described above referring to S 21 , when the user turns on the power switch  109  illustrated in  FIG. 2 , the acceptor  12  illustrated in  FIG. 6  accepts the power on operation and performs processing that is the same as or similar to the above-described S 22  to S 31 - 1  and S 31 - 2 , such that descriptions of which are omitted. 
     Referring now to  FIGS. 14 to 18 , operation of obtaining a new charge fee and sample data that reflect changed quality parameters is explained according to an embodiment of the present invention.  FIG. 14  is a data sequence diagram illustrating operation of obtaining quality parameters and a charge fee each reflecting the change in quality parameters, according to an embodiment of the present invention.  FIGS. 15 to 18  illustrate example screens to be displayed when configuring communication quality in providing content data as a service. In the screen of any one of  FIGS. 16 to 18 , information regarding the quality parameters, charge fee, and sample image are displayed together. If sample content data includes sample sound data, such sample sound data is output through the speaker  115 . 
     Referring to  FIG. 14 , the display control  17  of the terminal  10   aa  causes the display  120  to display a communication quality configuration screen (S 41 ). For example, the communication quality configuration screen of  FIG. 15  may be displayed, which displays various items such as the quality parameters (image quality, sound quality), charge fee, and sample image. In this screen of  FIG. 15 , the value for each item, which is determined by the service plan of the user, is not displayed. The screen of  FIG. 15  also displays the “request for service plan” key to be selected when requesting display of detailed contents of the current service, and the “cancel” key to be selected when closing the screen. As the user at the terminal  10   aa  selects the “request for service plan” key, the acceptor  12  accepts the request for displaying the contents of the current service provided to the user (S 42 ). The transmitter/receiver  11  of the management system  50  transmits a request for the quality parameters, charge fee, and sample data of the current service to the management system  50  (S 43 ). The terminal  10   aa  also transmits the terminal ID of the terminal  10   aa  to the management system  50 . The transmitter/receiver  51  of the management system  50  receives the request for the quality parameters, charge fee, and sample data, as well as the terminal ID of the terminal  10   aa.    
     Next, the data processor  59  of the management system  50  searches the service management table ( FIG. 12 ) using the terminal ID received at S 43  as a search key to obtain the quality parameters and the charge fee that are associated with the terminal ID (S 44 ). The generator  54  converts the quality parameters (such as the image quality parameter and/or the sound quality parameter) of sample content data (image data and/or sound data), read out by the data processor  59  from the memory  5000 , to match the quality parameters read at S 44 , to generate sample data for the terminal  10   aa  (S 45 ). 
     The transmitter/receiver  51  transmits, to the terminal  10   aa , the quality parameters and the charge fee that are read at S 44 , and the sample data generated at S 45  (S 46 ). The transmitter/receiver  11  of the terminal  10   aa  receives information regarding the quality parameters and charge fee, and sample data. 
     The display control  17  of the terminal  10   aa  causes the display  120  to display the quality parameters, charge fee, and sample data (S 47 ). For example, the communication quality configuration screen of  FIG. 16  may be displayed, which include information regarding the received quality parameters and charge fee, and an image of sample data. The screen of  FIG. 16  further displays the “request change” key to be selected when requesting change in quality parameter, and the “cancel” key to be selected when closing the screen of  FIG. 16 . 
     In this embodiment, it is assumed that the user at the terminal  10   aa  operates the operation key  108  to change the resolution from “SD” to “HD”, and selects the “request change” key. In such case, the acceptor  12  accepts the request for changing the communication quality (S 48 ). The transmitter/receiver  11  of the terminal  10   aa  requests the management system  50  for information regarding the quality parameters and charge fee that reflect the change, as well as sample data reflecting the change (S 49 ). Further, at S 49 , the transmitter/receiver  11  transmits the change in quality parameters that is accepted at S 48  to the management system  50 . The transmitter/receiver  51  receives the request for the quality parameters, charge fee, and sample data that reflect the change, and the change in quality parameters. 
     The calculator  55  refers to the additional fee management table ( FIG. 11 ) using the changed quality parameter that is received at S 49  to calculate a new charge fee reflecting the change in quality (S 50 ). More specifically, the data processor  59  searches the additional fee management table of  FIG. 11B  using the changed quality parameter (in this example, changing the resolution to “HD”) that is received at S 49  as a search key to obtain the additional fee for transmitting content data having the resolution value “HD”. The calculator  55  adds the obtained additional fee, as well as the additional fees for the other quality parameters, to the basic charge fee of the user at the terminal  10   aa  to calculate the new charge fee. Alternatively, the difference in additional fee due to the change in quality parameter value may be added to (or subtracted from) the currently set charge fee for the user at the terminal  10   aa.    
     The generator  54  converts quality parameters of sample content data (image data and/or sound data) read out by the data processor  59  from the memory  5000 , to match the quality parameters reflecting the change to obtain sample data reflecting the change (S 51 ). 
     The transmitter/receiver  51  transmits, to the terminal  10   aa , the quality parameters reflecting the changed quality received at S 49 , the charge fee calculated at S 50 , and the sample data generated at S 51  (S 52 ). The transmitter/receiver  11  of the terminal  10   aa  receives the quality parameters, charge fee, and sample data each reflecting the change in quality. 
     The display control  17  of the terminal  10   aa  causes the display  120  to display quality parameters, charge fee, and sample data each reflecting the change (S 53 ). For example, the communication quality configuration screen of  FIG. 17  may be displayed, which includes the quality parameters, charge fee, and sample image each of which reflects the change, in addition to the charge fee and sample image reflecting the unchanged quality (that is, information reflecting the current service plan). The screen of  FIG. 17  further includes the “confirm change” key to be selected when accepting the change in quality, and the “cancel” key to be selected when canceling the change in quality. The user at the terminal  10   aa  is able to compare between the sample image before the change, and the sample image after the change, to determine whether it is worthwhile to change the quality parameters with the additional fee. In this embodiment, the sample image is video image data. Alternatively, sounds may be generated based on sample sound data for output, such that the user can hear the sample sounds. Alternatively, the sample image may be a still image. 
     For example, a type of content data to be used for sample data may be determined based on specific parameters that are requested to be changed. In such case, in response to the request for changing specific parameters, the generator  54  may determine a type of content data to be generated based on a type of specific parameters to be changed. For example, if the user requests to change the resolution, the quality of image data after change can be checked with a still image. In such case, the generator  54  may generate still image data that reflects the changed values of resolution as sample content data. Similarly, if the user requests to change only the parameter that affects the sounds, the generator  54  may generate sound data that reflects the changed values of sound quality parameter, as sample content data. By selecting a type of content data for display based on a type of parameter to be changed, in case sound data or still image data is only needed to show the difference, the load on network can be reduced as still image data or sound data usually is less in data size. 
     When the user at the terminal  10   aa  presses the “confirm change” key with the operation key  108 , for example, the acceptor  12  accepts confirmation of the change in quality (S 54 ). The transmitter/receiver  11  transmits confirmation of changing the quality to the management system  50  (S 55 ). The transmitter/receiver  51  of the management system  50  receives the confirmation of changing the quality. 
     The manager  53  of the management system  50  causes the data processor  59  to change a record for the terminal ID “ 01   aa ” in the service management table ( FIG. 12 ) to reflect the changed quality parameters and the new charge fee (S 56 ). The transmitter/receiver  51  transmits information indicating that the change is complete to the terminal  10   aa  (S 57 ). The transmitter/receiver  11  of the terminal  10   aa  receives the information indicating completion of the change. 
     The display control  17  of the terminal  10   aa  causes the display  120  to display a message indicating that the change in quality is completed (S 58 ). For example, the communication quality configuration screen of  FIG. 18  may be displayed, which additionally includes the message “change reflected” at the upper side of the screen. The screen of  FIG. 18  further includes the “OK” key at the lower right. As the user at the terminal  10   aa  presses the “OK” key, operation of changing the quality parameters of content data ends. 
     Referring now to  FIG. 19 , operation of preparing for starting communication is described according to an embodiment of the present invention.  FIG. 19  is a data sequence diagram illustrating operation of preparing for starting communication. 
     First, when the user at the starting terminal  10   aa  presses the operation keys  108  illustrated in  FIG. 2  and selects the terminal  10   db , the acceptor  12  illustrated in  FIG. 6  accepts a request for starting communication with the counterpart terminal  10   db  (S 61 ). The transmitter/receiver  11  of the starting terminal  10   aa  transmits, to the management system  50 , start request information indicating a request for starting communication with the counterpart terminal  10   db  (S 62 ). The start request information includes the terminal ID “ 01   aa ” of the starting terminal  10   aa , and the terminal ID “ 01   db ” of the counterpart terminal  10   db . The transmitter/receiver  51  of the management system  50  obtains the start request information, and further receives the IP address of the starting terminal  10   aa , which is the transmission source. 
     The manager  53 , which obtains the terminal ID “ 01   aa ” of the starting terminal  10   aa  and the terminal ID “ 01   db ” of the counterpart terminal  10   db  from the start request information, changes the operating state field of each of records including the above-mentioned terminal IDs “ 01   aa ” and “ 01   db ” to “Online (Communicating)” in the terminal management table of  FIG. 9  (S 63 ). In this state, although the starting terminal  10   aa  and the counterpart terminal  10   db  have not started communicating, these terminals enter a communicating state, and, if another terminal  10  tries to communicate with the starting terminal  10   aa  or the counterpart terminal  10   db , a notification sound or display that indicates that the terminal is communicating is output. 
     The data processor  59  searches the service management table ( FIG. 12 ) using the terminal ID “ 01   aa ” of the starting terminal  10  as a search key to obtain the quality parameters of service contents for the terminal  10   aa  (S 64 ). The manager  53  generates a session ID (S 65 ). 
     The transmitter/receiver  51  transmits a request for establishing a session (“request for session”) to the starting terminal  10   aa  (S 66 - 1 ). The session establishing request includes the session ID generated at S 65 . The transmitter/receiver  11  of the starting terminal  10   aa  receives the session establishing request and the IP address of the management system  50 . The transmitter/receiver  51  of the management system  50  further transmits the session establishing request to the counterpart terminal  10   db  (S 66 - 2 ). The session establishing request includes the session ID generated at S 65 . The transmitter/receiver  11  of the counterpart terminal  10   db  receives the session establishing request and the IP address of the management system  50 . 
     Next, the data processor  59  of the management system  50  searches the terminal management table ( FIG. 9 ) using the terminal IDs of the starting terminal  10   aa  and the counterpart terminal  10   db , received at S 62 , as search keys, to read corresponding IP addresses (S 67 ). 
     The transmitter/receiver  51  of the management system  50  transmits the IP addresses of the starting terminal  10   aa  and the counterpart terminal  10   db  that are read at S 67 , the quality parameters read at S 64 , and the session ID generated at S 65 , to the relay device  30  (S 68 ). The transmitter/receiver  31  of the relay device  30  receives the IP addresses of the starting terminal  10   aa  and the counterpart terminal  10   db , the quality parameters read at S 64 , and the session ID generated at S 65 . 
     Next, the data processor  39  of the relay device  30  newly stores the session ID, the quality parameters, and the IP addresses of the terminals  10 , in association with each other in the service contents management table (see  FIG. 7 ) (S 69 ). The transmitter/receiver  31  of the relay device  30  establishes a communication session with the starting terminal  10   aa  using the session ID and the IP address of the starting terminal  10   aa  stored at S 69  (S 70 - 1 ). The transmitter/receiver  31  of the relay device  30  establishes a communication session with the counterpart terminal  10   db  using the session ID and the IP address of the counterpart terminal  10   db  stored at S 69  (S 70 - 2 ). 
     Referring to  FIG. 20 , operation of carrying out communication between the starting terminal  10   aa  and the counterpart terminal  10   db  is explained according to an embodiment of the present invention.  FIG. 20  is a data sequence diagram illustrating operation of carrying out communication between the starting terminal  10   aa  and the counterpart terminal  10   db . Since the one-way operation of transmitting image data and sound data from the terminal  10   aa  to the terminal  10   db  and the other-way operation of transmitting image data and sound data from the terminal  10   db  to the terminal  10   aa  are the same processing in terms of transmission/reception of image data and sound data, the former-mentioned one-way communication will be described, and the latter-mentioned other-way communication will be omitted. 
     At the starting terminal  10   aa , the transmitter/receiver  11  transmits image data of the subject and sound data of sounds, each captured by the communication control  13 , to the relay device  30  via the communication network  2 , through the communication session having the session ID “sel” (S 81 ). 
     The transmitter/receiver  31  of the relay device  30  receives the image data and the sound data as content data for transmission to the counterpart terminal  10   db . The changer  33  changes the quality parameters of the content data (image data and/or sound data), to match the quality parameters as managed by the service contents management table of  FIG. 7  (S 82 ). In this case, when the quality of the image data and the quality of the sound data transmitted from the starting terminal  10   aa  are values that are less than or equal to the image quality parameter and the sound quality parameter obtained from the service contents management table of  FIG. 7 , respectively, the changer  33  does not change the quality of the image data and the quality of the sound data. In contrast, when the quality of the image data transmitted from the starting terminal  10   aa  is a value that exceeds the image quality parameter, the changer  33  reduces the quality of the image data to the value of the image quality parameter. Similarly, when the quality of the sound data transmitted from the starting terminal  10   aa  is a value that exceeds the sound quality parameter, the changer  33  reduces the quality of the sound data to the value of the sound quality parameter. 
     The transmitter/receiver  31  of the relay device  30  transfers the image data and the sound data to the counterpart terminal  10   db  through the image/sound data session “sed” (S 83 ). Accordingly, the starting terminal  10   aa  can transmit image data and sound data having qualities that are based on the service contents of the starting terminal  10   aa  that sends the communication start request. In the case of transmitting image data and sound data from the counterpart terminal  10   db  to the starting terminal  10   aa  via the relay device  30 , image data and sound data having qualities that are based on the service contents of the starting terminal  10   aa  can be transmitted. 
     In the above-described embodiment, when the user at the terminal  10  requests to change the quality parameters of content data, the management system  50  sends a charge fee and sample data each reflecting the quality change to the terminal  10 . The terminal  10  causes the display  120  to display the changed quality parameters, as well as the charge fee and the sample image reflecting the changed quality parameters. That is, the user at the terminal  10  is able to instantly know the new charge fee and preview the sample image. With this information, the user can easily make a decision whether to change the quality parameters, or find out the best service contents (service plan) that matches the current user needs. 
     Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the disclosure of the present invention may be practiced otherwise than as specifically described herein. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. 
     For example, in response to a request for changing at least one quality parameter of content data, the management system  50  may send only a new charge fee to be updated to reflect the change in quality parameter for display at the communication terminal  10 . Further, in alternative to changing the communication quality to the higher value, the user may request to change the communication quality to the lower value. 
     The relay devices  30  and the management system  50  in the above-described embodiment may be configured by a single computer or a plurality of computers to which divided portions (functions) are arbitrarily allocated. In addition, a recording medium such as a CD-ROM storing the terminal control program, the relay device control program, or the communication management program in the above-described embodiment, is used as a program product in case of providing any one of the above programs to users within a certain country or outside that country. 
     In alternative to the display  120 , any other desired display such as a projector or a terminal display may be used. 
     In addition, although the case of a videoconference terminal has been described as an example of a communication terminal in the above-described embodiment, the embodiment is not limited to this case, and the communication system  1  may be a phone system such as an IP phone system or an Internet phone system. The communication terminal may be any one of a smart phone, a mobile phone, a car navigation terminal, and a wearable computer. The communication terminal further may be any one of a monitoring camera, a digital camera, an electronic blackboard, a projector, a game machine, a digital signage, or industrial equipment with a communication function. A wearable computer includes a watch and a head-mounted display. Industrial equipment includes office equipment such as a multifunction peripheral (MFP) printer product, medical equipment such as an endoscope, and agricultural equipment such as a cultivator. 
     In addition, although image data and sound data are described as examples of content data in the above-described embodiment, the content data is not limited to these items of data, and the content data may be touch data. In this case, a feeling obtained by a user&#39;s contact at one terminal side is transmitted to the other terminal side. Further, the content data may be smell data. In this case, a smell at one terminal side is transmitted to the other terminal side. In addition, the content data may be at least one of image data, sound data, touch data, and smell data. 
     In addition, although the case in which a videoconference is held by the communication system  1  has been described in the above-described embodiment, the embodiment is not limited to this case. The communication system  1  may be used in meetings, general conversation between family members or friends, or one-way presentation of information. 
     Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC) and conventional circuit components arranged to perform the recited functions. 
     The present invention can be implemented in any convenient form, for example using dedicated hardware, or a mixture of dedicated hardware and software. The present invention may be implemented as computer software implemented by one or more networked processing apparatuses. The network can comprise any conventional terrestrial or wireless communications network, such as the Internet. The processing apparatuses can compromise any suitably programmed apparatuses such as a general-purpose computer, personal digital assistant, mobile telephone (such as a WAP or 3G-compliant phone) and so on. Since the present invention can be implemented as software, each and every aspect of the present invention thus encompasses computer software implementable on a programmable device. The computer software can be provided to the programmable device using any storage medium for storing processor readable code such as a floppy disk, hard disk, CD ROM, magnetic tape device or solid state memory device. 
     The hardware platform includes any desired kind of hardware resources including, for example, a central processing unit (CPU), a random access memory (RAM), and a hard disk drive (HDD). The CPU may be implemented by any desired kind of any desired number of processor. The RAM may be implemented by any desired kind of volatile or non-volatile memory. The HDD may be implemented by any desired kind of non-volatile memory capable of storing a large amount of data. The hardware resources may additionally include an input device, an output device, or a network device, depending on the type of the apparatus. Alternatively, the HDD may be provided outside of the apparatus as long as the HDD is accessible. In this example, the CPU, such as a cache memory of the CPU, and the RAM may function as a physical memory or a primary memory of the apparatus, while the HDD may function as a secondary memory of the apparatus.