Patent Publication Number: US-2010110944-A1

Title: Communication terminal apparatus, communication administering apparatus, communication method, communication program, and recording medium

Description:
TECHNICAL FIELD 
     The present invention relates to a communication terminal apparatus that, using identification information, performs bidirectional communication; a communication administering apparatus that administers communication between communication apparatuses; and a communication method, communication program, and recording medium associated with these apparatuses. However, application of the present invention is not limited to the communication terminal apparatus, the communication administering apparatus, the communication method, the communication program, and the recording medium. 
     BACKGROUND ART 
     Conventionally, navigation apparatuses scroll the display of a map of the environs of a vehicle based on vehicular position according to the advancement of the vehicle, as well as search for a guide route to a destination, display the guide route on the map and guide the driver to the destination. Among such navigation apparatuses, a navigation apparatus supporting Vehicle Information and Communication System (VICS, registered trademark), receives information that is provided by VICS and concerns congestion, accidents, regulations, etc. and in real-time, displays the information on the map. 
     Through the use of VICS, a driver can avoid congested roads, roads closed to traffic, and roads on which an accident has occurred, thereby arriving at a destination in a short period of time. Beacons, including optical beacons and radio beacons, are provided on roads as communication administrating apparatuses to enable the navigation apparatus to utilize the VICS information. VICS information transmitted from these beacons can be received by the navigation apparatus (for example, refer to Patent Document 1 below). 
     The navigation apparatus not only receives the VICS information transmitted from the beacons, but can further transmit information concerning the vehicle, such as speed and position, to the beacon (up-link). The beacon, by receiving the information from the navigation apparatus, can acquire more detailed traffic information and further feedback this information to the navigation apparatus. 
     Patent Document 1: Japanese Laid-Open Patent Application Publication No. 2006-3292 
     DISCLOSURE OF INVENTION 
     Problem to be Solved by the Invention 
     However, to transmit VICS information from the beacon to the navigation apparatus as disclosed in Patent Document 1, identification information, such as an ID, is necessary to identify a navigation apparatus. Thus, conventional technology like that disclosed in Patent Document 1, for example, involves assigning a fixed ID to each navigation apparatus and transmitting VICS information based on the ID. 
     Use of the fixed ID enables behavior of the navigation apparatus to be completely captured and as a result, the behavior of the user is identified. Thus, a problem arises in that some users may regard the lack of anonymity and personal identification with repugnance. 
     Hence, a system is being developed that in place of a fixed ID, uses an ID (LID) that protects anonymity and does not identify the user of the navigation apparatus to perform communication. When LID is used, typically a communication terminal apparatus acquires from a given communication administrating apparatus, an ID randomly generated; and uses for communication, an ID unrelated to the communication terminal apparatus as and LID. 
     When a random ID (LID) is transmitted from the communication administrating apparatus to the communication terminal apparatus, the communication terminal apparatus must be designated as the recipient. Therefore, use of the LID between communication terminal apparatuses enables communication that protects anonymity; however, from the communication administrating apparatus, it can be known which LID has been sent to which communication terminal apparatus. Consequently, a problem arises in that, from the communication administrating apparatus, behavior of the communication terminal apparatus is identified. 
     Means For Solving Problem 
     A communication terminal apparatus according to the invention of claim  1  performs bidirectional communication with a designated communication destination using identification information acquired from a communication administrating apparatus. The communication terminal apparatus includes a requesting unit that inserts into request information requesting issue of identification information, time information related to transmission of the request information and transmits the request information to the communication administrating apparatus; and a setting unit that sets, as temporary identification information for communication performed with another communication terminal apparatus, identification information issued from the communication administrating apparatus in response to the request information. 
     A communication administrating apparatus according to the invention of claim  5  administrates issue of identification information used in communication between communication terminal apparatuses. The communication administrating apparatus includes a receiving unit that receives from a communication terminal apparatus, request information requesting identification information and inclusive of time information; a generating unit that, upon receipt of the request information by the receiving unit, generates the identification information using the request information that includes the time information; and an issuing unit that issues to the communication terminal apparatus, the identification information generated by the generating unit. 
     A communication terminal method according to the invention of claim  10  is a communication method of performing bidirectional communication with a designated communication destination using identification information acquired from a communication administrating apparatus. The communication terminal method includes a requesting step of inserting into request information requesting issue of identification information, time information related to transmission of the request information and transmitting the request information to the communication administrating apparatus; and a setting step of setting, as temporary identification information for communication performed with another communication terminal apparatus, identification information issued from the communication administrating apparatus in response to the request information. 
     A communication method according to the invention of claim  11  is a communication method of administrating issue of identification information used in communication between communication terminal apparatuses. The communication administrating method includes a receiving step of receiving from a communication terminal apparatus, request information requesting identification information and inclusive of time information; a generating step of generating, upon receipt of the request information at the receiving step, the identification information using the request information that includes the time information; and an issuing step of issuing to the communication terminal apparatus, the identification information generated at the generating step. 
     A communication program according to the invention of claim  12  causes a computer to execute the communication method according to claim  10  or  11 . 
     A computer-readable recording medium according to the invention of claim  13  stores therein the communication program according to claim  12 . 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram of a system configuration according to the present embodiment; 
         FIG. 2  is a flowchart of communication terminal apparatus processing; 
         FIG. 3  is a flowchart of communication administrating apparatus processing; 
         FIG. 4  is a diagram of system configuration in the example; 
         FIG. 5  is a block diagram of a hardware configuration of a navigation apparatus; 
         FIG. 6  is a hardware configuration of a server apparatus built-in a communication center; 
         FIG. 7  is a flowchart of processing for acquisition of anonymity-protecting ID of the navigation apparatus; and 
         FIG. 8  is a flowchart of processing for issuing an anonymity-protecting ID by the server apparatus. 
     
    
    
     EXPLANATIONS OF LETTERS OR NUMERALS 
     
         
         
           
               110  communication terminal apparatus 
               111  requesting unit 
               112  setting unit 
               120  communication administrating unit 
               121  receiving unit 
               122  generating unit 
               123  issuing unit 
           
         
       
    
     BEST MODE(S) FOR CARRYING OUT THE INVENTION 
     With reference to the accompanying drawings, preferred embodiments of a communication terminal apparatus, a communication administrating apparatus, a communication method, a communication program, and a recording medium according to the present invention will be explained. 
     (System Configuration) 
     First, a system configuration according to the present invention will be explained.  FIG. 1  is a block diagram of a system configuration according to the present embodiment. As depicted in  FIG. 1 , the present embodiment is made up of a system that includes communication terminal apparatuses  110  ( 110 A,  110 B,  110 C) and a communication administrating apparatus  120 . 
     One of the communication terminal apparatuses  110  (e.g., communication terminal apparatus  110 A), establishes bidirectional communication with another one of the communication apparatuses  110  (e.g., communication terminal apparatus  110 B) designated as a transmission destination. In performing the bidirectional communication, in order for the communication terminal apparatus  110 B and/or  110 C, which are transmission destinations of the communication terminal apparatus  110 A, to designate the communication terminal apparatus  110 A as a transmission origin, identification information is necessary. Further, by imparting a function of the communication terminal apparatus  110 A to the communication administrating apparatus  120 , the communication administrating apparatus  120  may be a transmission destination of the communication terminal apparatus  110 A. 
     With the system configuration according to the present embodiment, the communication terminal apparatuses  110  acquire from the communication administrating apparatus communication administrating apparatus  120 , identification information for performing bidirectional communication. Specifically, the communication terminal apparatuses  110  transmit to the communication administrating apparatus  120 , request information requesting the issue of identification information. The communication administrating apparatus  120 , upon the receipt of request information from a communication terminal apparatus  110 , generates random identification information, i.e., identification information protecting anonymity, and issues the information generated to the communication terminal apparatus  110  that has transmitted the request information, 
     Here, bidirectional communication between the communication terminal apparatuses  110  and the communication administrating apparatus  120  involves the request and issue of identification information. However, conventionally, in the processing of the request and issue of identification information, since a communication terminal apparatus  110  is designated as the recipient of issued identification information with respect to the communication administrating apparatus  120 , identification information unique to the apparatus is used in bidirectional communication with the communication administrating apparatus  120 . That is, the communication terminal apparatus  110  reveals the real name thereof to the communication administrating apparatus  120  to perform communication. 
     According to the present embodiment, to protect the anonymity of the communication terminal apparatus  110 , the communication terminal apparatus  110  uses identification information that protects anonymity even for bidirectional communication with the communication administrating apparatus  120 , i.e., the communication terminal apparatus  110  uses the identification information that protects anonymity for all communication. 
     The communication terminal apparatuses  110 , the communication administrating apparatus  120 , including respective functions and processing thereof, for performing communication that involves the communication terminal apparatuses  110  and uses the identification information that protects anonymity will be explained. 
     (Functional Configuration of Communication Terminal Apparatus) 
     A functional configuration of the communication terminal apparatuses  110  according to the present embodiment will be explained. As depicted in  FIG. 1 , each of the communication terminal apparatuses  110  is an apparatus that performs bidirectional communication with a designated transmission destination using identification information acquired from the communication administrating apparatus  120 , and includes a requesting unit  111  and a setting unit  112 . 
     The requesting unit  111  transmits to the communication administrating apparatus  120 , request information requesting issue of identification information and inclusive of time information concerning the transmission of the request information. The request information is information requesting the communication administrating apparatus  120  to issue identification information. Specifically, to enable the communication administrating apparatus  120  to recognize the request information, the request information is of a predetermined format, includes a given flag, etc. 
     As explained, the request information includes time information. The time information is used to distinguish, for example, the communication terminal apparatus  110 A from the communication terminal apparatuses  110 B,  110 C when the communication administrating apparatus  120  issues identification information to the communication terminal apparatus  110 A, which has sent the request information. That is, the request information inclusive of time information is the identification information that is used in the bidirectional communication between the communication terminal apparatus  110 A and the communication administrating apparatus  120  and further protects anonymity. 
     In this example, the time information is used as information to distinguish the communication terminal apparatus  110 A from the communication terminal apparatuses  110 B,  110 C. However, other information such as a character string randomly generated by the communication terminal apparatus  110 A may be included alternatively in the request information. 
     Further, the timing of the transmission of the request information by the request unit  111  may be arbitrarily set. For example, upon the instruction for commencement of bidirectional communication with the communication terminal apparatuses  110 B and  110 C by the user of the communication terminal apparatus  110 A, request information requesting identification information that is to be newly used is transmitted. Further, once request information is transmitted and the identification information is received, upon the occurrence of a predetermined event, request information may be transmitted. That is, by automatically switching the identification information, identification of the behavior of the communication terminal apparatus  110 A using the identification information can be prevented. 
     The setting unit  112  sets identification information issued from the communication administrating apparatus  120  in response to request information, as temporary identification information to be used in bidirectional communication with the communication terminal apparatuses  110 B,  110 C. As explained above, when the setting unit  112  receives identification information issued from the communication administrating apparatus  120 , identification information newly generated (identification information protecting anonymity) is transmitted from the communication administrating apparatus  120 . At this time, in the communication with the communication terminal apparatus  110 A, the communication administrating apparatus  120  uses, as the information protecting anonymity, the time information (or other information) included in the request information transmitted by the communication terminal apparatus  110 A. Therefore, the setting unit  112  sets the time information (or other information) as the identification information protecting the anonymity of the communication terminal apparatus  110 A. Further, by temporarily setting the identification information protecting anonymity, identification of the behavior of the communication terminal apparatus  110 A that sets identification information protecting anonymity and continuously uses the same identification information to use specific identification information, can be prevented. 
     Further, in the setting of the identification information protecting anonymity, a method may be used where the communication terminal apparatus  110  transmits proposed identification information to the communication administrating apparatus  120  and receives from the communication administrating apparatus  120 , authorization to use the proposed identification information as the identification information. In such a method, the requesting unit  111  transmits to the communication administrating apparatus  120 , request information and a request for authorization of a part of the request information or all of the request information (i.e., identification information). When the setting unit  112  receives a reply from the communication administrating apparatus  120  in response to the request for authorization to use all or a part of the request information as the identification information, the identification information is set as temporary identification information to be used in the communication with another communication terminal apparatus  110 . 
     (Functional Configuration of Communication Administrating Apparatus) 
     A functional configuration of the communication administrating apparatus according to the present embodiment will be explained. The communication administrating apparatus  120  is an apparatus that manages issue of identification information used in the communication between the communication terminal apparatuses  110 , and as depicted in  FIG. 1 , includes a receiving unit  121 , a generating unit  122 , and an issuing unit  123 . 
     The receiving unit  121  receives from the communication terminal apparatuses  110 , request information requesting issue of identification information. The request information, for example, is information requesting the issue of identification information to the communication terminal apparatus  110 A, which has sent the request information. To enable the receiving unit  121  to recognize the request information, the request information is of a predetermined format or includes a given flag. The request information includes time information or other information in lieu of the time information (e.g., a random character string). The time information (or other information) functions as identification information protecting anonymity and is for transmitting generated identification information to the communication terminal apparatus  110 A. 
     The generating unit  122 , upon receipt of request information by the receiving unit  121 , uses the time information included in the request information received and generates identification information. If other information is used in lieu of time information, the information used in lieu of the time information is used to generate the identification information. 
     The issuing unit  123  issues to the communication terminal apparatus  110 A, the identification information generated by the generating unit  122 , i.e., performs processing to transmit the identification information generated to the communication terminal apparatus  110 A that has sent the request information. To designate the communication terminal apparatus  110 A as the transmission destination when the identification information is transmitted, the time information, or other information, included in the request information is used as the identification information protecting anonymity. 
     If the identification information generated by the generating unit  122  is identification information that has been generated already and is currently being used as the identification information of another communication terminal apparatus  110  (e.g., communication terminal apparatus  110 B), i.e., if the identification information generated on this occasion is already being administered by the communication administrating apparatus  120 , the issuing unit  123  transmits to the communication terminal apparatus  110 A, an instruction to retransmit the request information. 
     As explained in paragraph 0031, when a method of transmitting proposed identification information from the communication terminal apparatus  110 A to the communication administrating apparatus communication administrating apparatus  120  and of receiving authorization to use the proposed identification information as identification information is performed, processing different from that above is necessary for the communication administrating apparatus  120  as well. Specifically, when request information and a request for authorization to use all or a part of the request information as identification information are received by the receiving unit  121 , if neither all nor a part of the request information is under administration as identification information, the generating unit  122  generates and returns a reply authorizing use of all or a part of the request information to the communication terminal apparatus  110 A. Such processing enables proposed identification information transmitted from the communication terminal apparatus  110 A to be utilized as actual identification information. 
     (Communication Terminal Apparatus Processing) 
     Processing performed by the communication terminal apparatuses  110  according to the present embodiment will be explained.  FIG. 2  is a flowchart of communication terminal apparatus processing. Here, as one example, processing to acquire identification information used by the communication terminal apparatus  110 A to communication with the communication terminal apparatuses  110 B,  110 C will be explained. Processing to acquire identification information by the communication terminal apparatus  110 B,  110 C is identical. 
     As depicted in the flowchart of  FIG. 2 , it is determined whether a given event has occurred with respect to the communication terminal, apparatus  110 A (step S 201 ). The given event is an event requiring acquisition of identification information, such as a new setting of the identification information, a required change, etc. Specifically, for example, the event may be start-up of the communication terminal apparatus  110 A, the elapse of a given period from the acquisition of identification information from the communication administrating apparatus  120 , may be appropriately set by the user, etc. 
     At step S 201 , detection of the given event is waited for (step S 201 : NO). When the given event occurs (step S 201 : YES), the requesting unit  111  acquires time information concerning the transmission of the request information (step S 202 ). Further to acquire the identification information, the requesting unit  111  inserts the time information acquired at step S 202  into the request information and transmits the request information to the communication administrating apparatus  120  (step S 203 ). 
     The time information acquired at step S 202  is inserted into the request information (step S 203 ); however, this is only one example. If the information does not identify the communication terminal apparatus  110 A as the communication terminal apparatus  110  that has transmitted the request information, other information may be used. For example, a character string randomly generated by the communication terminal apparatus  110 A may be used. In such a case, at step S 203 , the generated character string is inserted into the request information and the request information is transmitted to the communication administrating apparatus  120 . 
     Request processing at the communication terminal apparatus  110 A to acquire identification information from the communication administrating apparatus  120  ends at step S 203  and thereafter, flow proceeds to processing to acquire identification information from the communication administrating apparatus  120  and to use the identification information acquired in bidirectional communication with the communication terminal apparatuses  110 B,  110 C. 
     At the communication terminal apparatus  110 A that has completed the processing at step S 203 , it is determined whether identification information issued from the communication administrating apparatus  120  has been received (step S 204 ). Here, receipt of the identification information is waited for (step S 204 : NO). Upon receipt of the identification information (step S 204 : YES), the setting unit  112  sets the identification information received as communication-use identification information (step S 205 ). 
     Finally, at the communication terminal apparatus  110 A it is determined whether communication is to be ended (step S 206 ). At step S 206 , if communication is to be continued (step S 206 : NO), flow returns to the processing at step S 202 , communication continues and if a predetermined event, the switching of identification information, occurs, flow proceeds to processing for acquiring the new identification information. On the other hand, if communication is to be terminated (step S 206 : YES), a series of the processing ends. 
     (Processing by Communication Administrating Apparatus) 
     Next, processing performed by the communication administrating apparatus  120  according to the present embodiment will be explained.  FIG. 3  is a flowchart of communication administrating apparatus processing. The communication administrating apparatus  120  generates identification information in response to a request for the issue of identification information from a communication terminal apparatus communication terminal apparatus communication terminal apparatus  110  and transmits the identification information generated to the communication terminal apparatus  110  that has transmitted the request. 
     As depicted in the flowchart of  FIG. 3 , the communication administrating apparatus  120  determines whether request information requesting issue of identification information has been received from the communication terminal apparatus  110 A (step S 301 ). Here, request information is determined to have been received when, for example, a predetermined condition is met such as a predetermined format indicative of request information and a flag indicating request information. 
     At step S 301 , receipt of request information is waited for (step S 301 : NO). Upon receipt of request information (step S 301 : YES), it is determined whether the request information received includes time information (step S 302 ). If the request information includes time information (step S 302 : YES), the time information is used as identification information when transmitting generated identification information to the communication terminal apparatus  110 A that has transmitted the request information. Accordingly, using the time information confirmed at step S 302 , the communication administrating apparatus  120  generates the identification information (step S 303 ). 
     At step S 302 , if the request information does not include time information (step S 302 : NO), other information is included as the identification information to be used for transmissions back to the communication terminal apparatus  110 A (e.g., a random character string generated by the communication terminal apparatus  110 A); hence, this information is used to generate the identification information (step S 304 ). 
     Upon generation of the identification information for communication terminal apparatus  110 A at step S 303  or S 304 , it is determined whether the generated identification information is information has been generated previously according to request information from another communication terminal apparatus  110  (e.g., communication terminal apparatus  110 B,  110 C) and is currently being used in bidirectional communication, i.e., whether the generated identification information coincides with identification information under administration of the communication administrating apparatus  120  (step S 305 ). 
     At step S 305 , if the generated identification information coincides with identification information under administration of the communication administrating apparatus  120  (step S 305 : YES), the generated identification information cannot be used; hence, the communication administrating apparatus  120  transmits to the communication terminal apparatus  110 A, an instruction to retransmit the request information (step S 307 ), flow returns to step S 301 , and processing remains in standby until new request information is received. 
     At step S 305 , if the generated identification information and identification information under administration do not coincide (step S 305 : NO), the communication administrating apparatus  120  issues the generated identification information to the communication terminal apparatus  110 A (step S 306 ), and a series of the processing ends. 
     As explained, according to the present embodiment, a communication terminal apparatus  110  uses identification information issued by the communication administrating apparatus  120  to perform anonymous bidirectional communication with other communication terminal apparatuses  110 . Further, upon receipt of identification information issued from the communication administrating apparatus  120 , communication that utilizes time information, a random character string, etc. as identification information protecting anonymity is performed. Therefore, the communication terminal apparatuses  110  can perform communication that maintains anonymity. 
     Example 
     An example of the present invention will be explained. In the example, the communication terminal apparatus  110  according to the present embodiment is applied as one function of a navigation apparatus. Further, the communication administrating apparatus  120  is implemented by a built-in server apparatus at a communication center that relays communication between the navigation apparatus and other communication terminal apparatuses. 
     (System Configuration) 
     System configuration of the example will be explained.  FIG. 4  is a diagram of the system configuration in the example. As depicted in  FIG. 4 , in a communication system  400  of a communication center  403  receives, by way of a beacon  402 , a communication request transmitted from a vehicle  401 , and by way of the communication center  403  establishes communication with a designated navigation apparatus equipped on another vehicle  401 , a service provider  404  (service providers A to C), etc. 
     When a vehicle  401  communicates with another navigation apparatus, service provider  404 , etc., the navigation apparatus equipped on the vehicle  401  acquires from the communication center  403 , an anonymity-protecting ID that does not identify the navigation apparatus. The navigation apparatus implements bidirectional communication using the anonymity-protecting ID acquired. 
     (Hardware Configuration of Navigation Apparatus) 
     Hardware configuration of the navigation apparatus will be explained.  FIG. 5  is a block diagram of a hardware configuration of the navigation apparatus. A navigation apparatus  500  is equipped on the vehicle  401 . 
     As depicted in  FIG. 5 , the navigation apparatus  500  includes a CPU  501 , a ROM  502 , a RAM (memory)  503 , a magnetic disk drive  504 , a magnetic disk  505 , an optical disk drive  506 , an optical disk  507 , an audio I/F (interface)  508 , a microphone  509 , a speaker  510 , an input device  511 , a video I/F  512 , a display  513 , a camera  514 , a communication I/F (interface)  515 , a CPS unit  516 , and various sensors  517 , all components respectively connected through a bus  520 . 
     The CPU  501  governs overall control of the navigation apparatus  500 . The ROM  502  stores therein various programs such as a boot program, navigation program, a communication program, etc. The RAM  503  is used a work area of the CPU  501 . 
     The magnetic disk drive  504  controls the reading and the writing of data with respect to the magnetic disk  505  under the control of the CPU  501 . The magnetic disk  505  records data written thereto under the control of the magnetic disk drive  504 . As the magnetic disk  505 , for example, an HD (hard disk), FD (flexible disk), etc. may be used. 
     The optical disk drive  506  controls the reading and the writing of the data with respect to the optical disk  507  under the control of the CPU  501 . The optical disk  507  is a removable recording medium from which data is read under the control of the optical disk drive  506 . The optical disk  507  may be a writable recording medium. As the removal recording medium, a medium other than the optical disk  507  can be employed, such as an MO and a memory card. 
     The audio I/F  508  is connected with the microphone  509  for audio input and the speaker  510  for audio output. Sound received by the microphone  509  is subjected to A/D conversion at the audio I/F  508 . The speaker  510  outputs audio. Sound input from the microphone  509  may be recorded as audio data on the magnetic disk  505  or the optical disk  507 . 
     The input device  511  may be, for example, a remote controller having keys used to input characters, numerical values, or various kinds of instructions, a keyboard, a mouse, or a touch panel. Further, the input device  511  may be connected to other information processing terminals, such a digital camera and a mobile phone terminal, to input and output data. 
     The video I/F  512  is connected to the display  513  for video output and the camera  514  for video input. The video I/F  512  is made up of, for example, a graphic controller that controls the display  513 , a buffer memory such as VRAM (Video RAM) that temporarily stores immediately displayable image information, and a control IC that controls the display  513  based on image data output from the graphic controller. 
     The display  513  displays icons, cursors, menus, windows, or various data such as text and images. A CRT, a TFT liquid crystal display, a plasma display and so on can be employed as the display  513 . The camera  514  captures images inside and outside the vehicle and outputs the images as data. Images captured by the camera  514  may be recorded on the magnetic disk  505  or the optical disk  507  as image data. 
     The communication I/F  515  performs wireless communication with the beacon  402  (refer to  FIG. 4 ) and through the beacon  402  transmits information to the communication center  403 . Further, the communication I/F  515  is further connected to various communication networks to transmit and receive information. 
     The network includes a LAN, a WAN, a public line network, a mobile telephone network and so on. Specifically, the communication I/F  515  is made up of, for example, an FM tuner, a VICS/beacon receiver, a radio navigation apparatus, and other navigation apparatuses, and acquires road traffic information concerning congestion and traffic regulations distributed from the beacon  402 . As the road traffic information, for example, VICS information is received. The VICS information is road traffic information provided by Vehicle Information Center System (VICS) and concerns traffic congestion, accidents, regulations, etc. The VICS information acquired is displayed by the navigation apparatus in real-time. VICS is a registered trademark. 
     The GPS unit  516  receives signals from GPS satellites and outputs information concerning the position of the vehicle  401  (refer to  FIG. 4 ) in which the navigation apparatus  500  is equipped. The information output by the GPS unit  516  is used together with values output from various sensors, described hereinafter, in the calculation of the current position of the vehicle  401 , by the CPU  501 . Information indicative of current position includes, for example, information indicating one point on map data, such as latitude, longitude, altitude, etc. 
     The various sensors  517  include a vehicular speed sensor and an angular speed sensor that respectively output information used to determine the position and behavior of the vehicle. Values output from the various sensors  517  are used by the CPU  501  to compute the current position and measure changes in speed, direction, etc. 
     In making a correlation with the hardware configuration of the navigation apparatus  500 , the requesting unit  111  of the communication terminal apparatus  110  depicted in  FIG. 1  is implemented by, for example, the CPU  501 , the ROM  502 , the RAM  503 , and the input device  511 . The setting unit is implemented by, for example, the CPU  501 , the ROM  502 , and the RAM  503 . 
     (Hardware Configuration of Server Apparatus) 
     A hardware configuration of a server apparatus built-in the communication center  403 .  FIG. 6  is a hardware configuration of a server apparatus built-in the communication center. As depicted in  FIG. 6 , a server apparatus  600  includes a CPU  601 , a ROM  602 , a RAM  603 , a magnetic disk drive  604 , a magnetic disk  605 , an input device  606 , and a communication I/F (interface), respectively connected through a bus  610 . 
     The CPU  601  governs overall control of the server apparatus  600 . The ROM  602  stores therein various programs such as, route retrieving program, a guidance program, a communication program, etc. in addition to a boot program. 
     The RAM  603  is used a work area of the CPU  601 . The magnetic disk drive  604  controls the reading and the writing of data with respect to the magnetic disk  605  under the control of the CPU  601 . The magnetic disk  605  records data written thereto under the control of the magnetic disk drive  604 . 
     The input device  606  has keys used to input characters, numerical values, or various kinds of instructions and is equipped with an external connector enabling connection of an independent keyboard. Since the input device  606  is provided for an apparatus intended for use as the server apparatus  600  built into a communication center that administers communication, the input device  606  may be a device that can be used by only designated personnel. 
     The communication I/F (interface)  607  is wirelessly connected to a communication network and functions to interface the CPU  601  with the navigation apparatus  500 , other communication terminal apparatuses, the service providers  404 , etc. Communication between the navigation apparatus  500  and other communication terminal apparatuses, the service providers  404  through the communication I/F may be performed directly, through a base station, etc. The communication I/F  607  is wirelessly connected to communication networks such as the Internet and functions as an interface between the CPU  601  and the communication networks. 
     With respect to the server apparatus  600 , the receiving unit  121  and the issuing unit  123  of the communication administrating apparatus  120  depicted in  FIG. 1 , are implemented by, for example, the CPU  601 , the ROM,  602 , the RAM  603 , and the communication I/F  607 . The generating unit  122  is implemented by, for example, the CPU  601 , the ROM  602 , and the RAM  603 . 
     (Processing for Acquisition of Anonymity-Protecting ID of Navigation Apparatus) 
     Processing, executed in the system according to the present example, to acquire the anonymity-protecting ID used when the navigation apparatus  500  communicates with a specific service provider will be explained.  FIG. 7  is a flowchart of processing for acquisition of anonymity-protecting ID of the navigation apparatus. When the navigation apparatus  500  does not wish the behavior thereof to be identified, the navigation apparatus  500  uses the anonymity-protecting ID described above. The anonymity-protecting ID, unlike the usual ID, is a randomly generated character string. Therefore, by only referencing the anonymity-protecting ID formed by a character string, it is not known to which navigation apparatus  500  the anonymity-protecting ID is associated. 
     As depicted in the flowchart of  FIG. 7 , the navigation apparatus  500  determines whether an anonymity-protecting ID switching event has occurred (step S 701 ). Here, an anonymity-protecting ID switching event is, for example, ignition of the engine of the vehicle  401 , which does not have an anonymity-protecting ID stored, or is an event such as the lapse of a given period of time, the vehicle  401  traveling a given distance, etc. and can be appropriately set by the user of the navigation apparatus  500 . 
     At step S 701 , the navigation apparatus  500  waits until the anonymity-protecting ID switching event has occurred (step S 701 : NO). Upon occurrence of the event (step S 701 : YES), the navigation apparatus  500  acquires an ID form for requesting a new anonymity-protecting ID (step S 702 ) and further acquires the current time to be used in the ID form (step S 703 ). 
     From the time acquired at step S 703 , the navigation apparatus  500  generates a time character string to be stored in the ID form (step S 704 ). The navigation apparatus  500  inserts the time character string generated at step S 704  into the ID form acquired at step S 702 , and generates an ID for requesting an anonymity-protecting ID (step S 705 ). 
     The ID generated at step S 705  and for requesting an anonymity-protecting ID may be an anonymity-protecting ID proposed for this occasion. In such a case, the ID generated for requesting an anonymity-protecting ID and a request for authorization to use the ID as an anonymity-protecting ID are transmitted to the server apparatus  600 . Upon receipt of a response from the server apparatus  600  indicating authorization, the navigation apparatus  500  sets the ID for requesting an anonymity-protecting ID as the anonymity-protecting ID. 
     The ID generated at step S 705  and for requesting an anonymity-protecting ID is used to transmit a communication request to the server apparatus  600  of the communication center  403  (step S 706 ). Upon completion of the processing at step S 706 , the navigation apparatus  500  determines whether a new anonymity-protecting ID has been received from the server apparatus  600  of the communication center  403  in response to the communication request transmitted at step S 706  (step S 707 ). 
     As explained above, when the ID generated at step S 705  and for requesting an anonymity-protecting ID is proposed as the anonymity-protecting ID for this occasion, the navigation apparatus  500  may determine whether a reply has been received authorizing the ID proposed as the anonymity-protecting ID and transmitted to the server apparatus  600 . 
     At step S 707 , if a new anonymity-protecting ID is not received (step S 707 : NO), the navigation apparatus  500  determines whether a request for retransmission of the communication request has been received from the server apparatus  600  (step S 708 ). If a request for retransmission of the communication request has been received (step S 708 : YES), flow returns to the processing at step S 702  and the processing for transmitting a communication request using the ID for requesting an anonymity-protecting ID is repeated (steps S 702  to S 706 ). If the ID generated at step S 705  and for requesting an anonymity-protecting ID is proposed as the anonymity-protecting ID for this occasion and no reply from the server apparatus authorizing identification information has been received, “NO” is determined at step S 707 . 
     On the other hand, at step S 708 , if a request for retransmission of the communication request has not been received (step S 708 : NO), flow returns to the processing at step S 707  and the navigation apparatus  500  determines again whether a new anonymity-protecting ID has been received. Thus, the navigation apparatus  500  is in a standby state until a state in which either a new anonymity-protecting ID is received or a request for retransmission of the communication request is received. 
     At step S 707 , upon receipt of a new anonymity-protecting ID, the navigation apparatus  500  determines whether communication is to be performed (step S 709 ). At step S 709 , determination whether to perform communication is based on an instruction from the user of the navigation apparatus  500  to commence communication, an instruction from a higher level program to commence communication, etc. 
     At step S 709 , waiting occurs until it is determined that communication is to commence (step S 709 : NO). Upon determination that communication is to commence (step S 709 : YES), the navigation apparatus  500  begins communication using the anonymity-protecting ID received at step S 707  (step S 710 ), and a series of processing to acquire an anonymity-protecting ID ends. 
     (Processing for Issuing an Anonymity-Protecting ID by the Server Apparatus) 
     Processing for issuing an anonymity-protecting ID performed by the server apparatus  600  of the communication center  403  when a communication request is transmitted when ID switching processing has been performed at the navigation apparatus  500  will be explained.  FIG. 8  is a flowchart of processing for issuing an anonymity-protecting ID by the server apparatus. 
     As depicted in the flowchart of  FIG. 8 , the server apparatus  600  determines whether a communication request has been received from the navigation apparatus  500  (step S 801 ). Here, the server apparatus  600  waits until a communication request is received from the navigation apparatus  500  (step S 801 : NO). Upon receipt of a communication request (step S 801 : YES), the server apparatus  600  determines whether the communication request received is a request for an anonymity-protecting ID (step S 802 ). At step S 802 , if the communication request received is not a request for an anonymity-protecting ID (step S 802 : NO), a series of the processing ends. 
     At step S 802 , determination of whether the communication request received is a request for an anonymity-protecting ID may be determined by determining whether the communication request coincides with a predetermined format, or whether a predetermined flag indicative of a communication request is included, or may be arbitrarily set. 
     At step S 802 , if the communication request is a request for an anonymity-protecting ID (step S 802 : YES), the server apparatus  600  acquires the time character string from the ID of the communication request (step S 803 ). The server apparatus  600  then determines whether the time character string acquired at step S 803  coincides with a time character string acquired from another communicating terminal (navigation apparatus  500 ) (step S 804 ). 
     At step S 804 , if it determined that the time character string does not coincide (step S 804 : NO), the server apparatus  600  generates a new anonymity-protecting ID to be used by the navigation apparatus  500  that has transmitted the communication request (step S 805 ), and transmits to the navigation apparatus  500  that has transmitted the communication request, the anonymity-protecting ID generated (step S 806 ), ending a series of the processing. As explained with reference to  FIG. 7 , if the server apparatus  600  receives a proposed anonymity-protecting ID (e.g., the ID for requesting an anonymity-protecting ID) from the navigation apparatus  500 , at step S 805 , a reply is generated authorizing use of the proposed anonymity-protecting ID as the anonymity-protecting ID. 
     On the other hand, at step S 804 , if the time character string is determined to coincide (step S 804 : YES), the navigation apparatuses  500  cannot be distinguished from each other and hence, the server apparatus  600  transmits a request for retransmission of the communication request to the navigation apparatus  500  that has transmitted the communication request (step S 807 ). Subsequently, flow returns to the processing at step S 801  and the server apparatus  600  remains in standby until a communication request is received in response to the request for retransmission transmitted at step S 807 . 
     As explained, according to the present example, the navigation apparatus  500  uses an anonymity-protecting ID issued from the server apparatus  600  of the communication center  403  to perform, with the navigation apparatuses  500  equipped on other vehicles  401  and the service providers  404 , bidirectional communication that protects anonymity. Upon receipt of an anonymity-protecting ID issued by the server apparatus  600  of the communication center  403 , the navigation apparatus  500  performs communication using identification information that protects anonymity, such as time information and random character strings. Therefore, the navigation apparatus  500  can perform communication that maintains anonymity. 
     The communication method explained in the present embodiment can be implemented by a computer, such as a personal computer and a workstation, executing a program that is prepared in advance. The program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read out from the recording medium by a computer. The program can be distributed through a network such as the Internet.