Patent Publication Number: US-2007117632-A1

Title: Communication game apparatus, system, method and program

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a communication game apparatus, a communication game system, a communication game method, and a communication game program for playing a competitive game by transmitting and receiving game data among plural apparatuses.  
      2. Description of the Related Art  
      Conventionally, there is known a competitive car race game for performing a car race by connecting plural game terminals to one another via a network and operating operation units provided in the respective game terminals to drive vehicles in a game space (see, for example, Japanese Patent Application Laid-Open No. 2002-28373). There is also known a game system for controlling a data quantity of communication via a network by game terminals by means of designating a size of a partial game world using plural game terminals (see, for example, Japanese Patent Application Laid-Open No. 2002-253866).  
      In playing a competitive car race game using plural game terminals connected to one another via a network, when data necessary for the game is transmitted and received among the respective game terminals, as the number of game terminals participating in the game increases, a data quantity transmitted and received among the respective game terminals increases. However, usually, since there is a limit in a communication band usable by the respective game terminals, when a data quantity transmitted and received is excessively large, excessive time is required for the transmission and reception of the data. Therefore, a long time is required until the respective game apparatuses receive data of the other game terminals or an interval for receiving data is extended to deteriorate computation accuracy in computing actions of opponents at a predetermined interval. Thus, the actions of the opponents become unnatural to spoil the feeling of realistic sense of the game. It is possible to reduce a data quantity transmitted and received between the respective game terminals and the network by using the method of the game system disclosed in Japanese Patent Application Laid-Open No. 2002-253866. However, the same problem occurs after all when the number of game terminals increases and a data quantity exceeds the communication band. Therefore, this method does not present a fundamental solution.  
     SUMMARY OF THE INVENTION  
      The invention has been devised in view of such problems and it is an object of the invention to provide a communication game apparatus, a communication game system, a communication game method, and a communication game program that can improve, in a competitive game, the feeling of realistic sense of the game by preventing actions of opponents from becoming unnatural.  
      A communication game apparatus of the invention is a communication game apparatus to which plural opponent game apparatuses (the other plural communication apparatuses) are connected via communication lines. The communication game apparatus includes: a communication-frequency setting unit that variably sets a communication frequency of transmitting and receiving game data between the communication game apparatus and each of the plural opponent game apparatuses according to contents of a game in progress; and a communicating unit that performs transmission and reception of the game data between the communication game apparatus and each of the plural opponent game apparatuses at the communication frequency set by the communication-frequency setting unit.  
      A communication game system of the invention is a communication game system in which plural communication game apparatuses are connected to one another via a network. Each of the plural communication game apparatuses includes: a communication-frequency setting unit that variably sets a communication frequency of transmitting and receiving game data between the communication game apparatus and each of the other plural communication game apparatuses excluding the own apparatus according to contents of a game in progress; and a communicating unit that performs transmission and reception of the game data between the communication game apparatus and each of the plural communication game apparatuses excluding the own apparatus at the communication frequency set by the communication-frequency setting unit.  
      A communication game method of the invention is a communication game method of transmitting and receiving game data in a communication game system in which plural communication game apparatuses are connected to one another via a network. The communication game method includes: a communication-frequency setting step of variably setting, in each of the plural communication game apparatuses, a communication frequency of transmitting and receiving game data between the communication game apparatus and each of the other plural communication game apparatuses excluding the own apparatus according to contents of a game in progress; and a communicating step of performing transmission and reception of the game data between the communication game apparatus and each of the plural communication game apparatuses excluding the own apparatus at the communication frequency set in the communication-frequency setting step.  
      A communication game program of the invention is a communication game program that causes a computer to function as: a communication-frequency setting unit that variably sets a communication frequency of transmitting and receiving game data between a communication game apparatus and each of plural opponent game apparatuses connected to the communication game apparatus via communication lines according to contents of a game in progress; and a communicating unit that performs transmission and reception of the game data between the communication game apparatus and each of the plural opponent game apparatuses at the communication frequency set by the communication-frequency setting unit.  
      Consequently, when transmission and reception of game data are performed between the communication game apparatus and the plural opponent game apparatuses (or, the other plural communication game apparatuses), it is possible to set a communication frequency for each of the apparatuses according to contents of the game. Thus, it is possible to increase a frequency of acquiring game data concerning a part of opponent characters (the other characters excluding the player-character) according to importance or the like, prevent actions from becoming unnatural by improving accuracy of prediction of the actions, and improve the feeling of realistic sense of the game.  
      It is desirable that the communication game apparatus further includes a character-action computing unit that computes, on the basis of the game data received by the communicating unit, an action of a player-character corresponding to the own apparatus and actions of plural opponent characters corresponding to the plural opponent game apparatuses (or, the other plural communication game apparatuses), respectively, and the communication-frequency setting unit sets a communication frequency on the basis of a relative relation between the player-character and each of the plural opponent characters. This makes it possible to reduce an interval of acquisition of game data concerning opponent characters having a close relative relation with the player-character.  
      It is desirable that the communication-frequency setting unit sets a high communication frequency between the communication game apparatus and opponent game apparatuses (or, the other communication game apparatuses) corresponding to opponent characters close to the player-character and sets a low communication frequency between the communication game apparatus and opponent game apparatuses (or, the other communication game apparatuses) corresponding to opponent characters distant from the player-character. Consequently, since data is frequently acquired for opponent characters present around the player-character operated by the player, it is possible to reduce a degree of impression that actions of characters are unnatural. It is possible to reduce a data quantity of transmitted and received game data by setting a long interval of acquisition of data for opponent characters having low importance and distant from the communication game apparatus.  
      It is desirable that the communication-frequency setting unit sets a high communication frequency between the communication game apparatus and opponent game apparatuses corresponding to opponent characters highly likely to affect an action of the player-character and sets a low communication frequency between the communication game apparatus and the opponent game apparatuses corresponding to the other opponent characters. Consequently, since data is frequently acquired for opponent characters highly likely to affect actions of the player-character operated by the player, it is possible to reduce a degree of an impression that actions of characters are unnatural. Further, it is possible to reduce a data quantity of transmitted and received game data by setting a long interval of acquisition of data for opponent characters that are less likely to affect actions of the player-characters.  
      Further, it is desirable that a predetermined communication bandwidth is set for at least one of the transmission and the reception of game data via the communication lines and the communication-frequency setting unit includes a bandwidth setting unit that sets a proportion of a bandwidth to be allocated to each of the plural opponent game apparatuses (or, the other communication game apparatuses) to a communication bandwidth according to a level of a communication frequency. This makes it possible to allocate limited communication bandwidth to each of the opponent game apparatuses (or, to each of the other communication game apparatuses) and effectively use the communication bandwidth and makes it possible to secure a relatively wide bandwidth for opponent characters having a relatively close relation and realize prompt data acquisition.  
      It is desirable that a fixed value is set for one traffic of game data transmitted and received between the communication game apparatus and each of the plural opponent game apparatuses (or, the other communication game apparatuses) and the communication-frequency setting unit further includes a transmission-timing judging unit that accumulates values of the bandwidth allocated, which are set by the bandwidth setting unit, for the respective opponent game apparatuses (or, for the respective other communication game apparatuses) and judges that transmission timing for the game data has come when the accumulated values reaches the fixed value. This makes it possible to transmit and receive the game data at a frequency according to each of the communication bandwidth allocated.  
      It is desirable that the transmission-timing judging unit performs a judging operation at a predetermined time interval. Consequently, since it is judged whether transmission of the game data is performed every fixed interval, it is possible to transmit the game data at a shorter interval as a communication bandwidth secured is wider.  
      It is desirable that, when a degree of cooperation between the player-character corresponding to the own apparatus and each of the plural opponent characters corresponding to the plural opponent game apparatuses is set according to game contents, the communication-frequency setting unit sets a communication frequency taking into account the degree of cooperation. This makes it possible to set a high communication frequency for opponent game apparatuses of opponent characters that have a high degree of cooperation, for example, have a specific relation with the player-character.  
      It is desirable that parameters indicating individualities of the respective opponent characters are set for each of the plural opponent characters corresponding to the plural opponent game apparatuses and the communication-frequency setting unit sets a communication frequency according to the parameters. This makes it possible to acquire game data at a high communication frequency for, for example, opponent characters that have high ability values and are capable of performing quick movements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a diagram showing an overall configuration of a competitive game system according to an embodiment of the invention;  
       FIG. 2  is a diagram showing a detailed configuration of a game terminal;  
       FIG. 3  is a flow chart showing an operation procedure mainly related to transmission of game data performed in the game terminal;  
       FIG. 4  is a diagram showing a specific example of distance calculation;  
       FIG. 5  is a diagram showing a specific example of a usable bandwidth calculated on the basis of a distance shown in  FIG. 4 ; and  
       FIGS. 6A and 6B  are diagrams showing specific examples of an operation for accumulating data and an operation for judging transmission timing.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      A competitive communication game system according to an embodiment of the invention will be hereinafter explained in detail with reference to the accompanying drawings.  FIG. 1  is a diagram showing an overall configuration of the competitive communication game system according to this embodiment. As shown in  FIG. 1 , the competitive communication game system according to this embodiment includes plural game terminals  10  connected to one another via a network  30  and a game server  20 . For example, it is possible to use the Internet or the like as the network  20 . The respective game terminals  10  and the network  30  are always connected. The respective game terminals  10  are used to play a competitive car race game. Players can drive racing cars of the players themselves along a course provided in a virtual three-dimensional game space and participate in a car race by using the game terminals  10 .  
       FIG. 2  is a diagram showing a detailed configuration of the game terminal  10 . As shown in  FIG. 2 , the game terminal  10  according to this embodiment includes a game apparatus  100  that performs a predetermined game computation and outputs a video signal of a game screen and an audio signal of various kinds of sound effect or the like by executing a communication game program stored in a DVD-ROM  190  serving as an information recording medium, a television monitor apparatus  200  connected to the game apparatus  100 , and a controller  300  manually operated by players.  
      The television monitor apparatus  200  includes a display  210  that displays a game screen on a display screen on the basis of a video signal inputted from the game apparatus  100  and a speaker  220  that converts an audio signal inputted from the game apparatus  100  into sound. The display  210  is constituted by, for example, a CRT (cathode ray tube), an LCD (a liquid crystal display), or a liquid crystal projector. The controller  300  includes a cross key that can arbitrarily point eight directions and plural push button switches that are selectively depressed as required. In order to give a player the feeling of actually participating in a car race, a controller dedicated for vehicle driving game including a steering wheel and a transmission may be used.  
      The game apparatus  100  includes a game computing section  110 , a communication interface section (communication IF)  160 , an image generating section  180 , an image output section  182 , an audio output section  184 , and a disk reading section  188 . The game computing section  110  is for performing various kind of game computation. The game computing section  110  is realized by, for example, executing a communication game program using a computer including a CPU, a ROM, and a RAM. Details of the game computing section  110  will be described later.  
      The image generating section  180  converts, on the basis of data concerning positions and the like of respective objects in a three-dimensional game space obtained by the computation by the game computing section  110  and eye point positions set at the time, the respective objects in the three-dimensional game space into a projected plane of a predetermined eye-point coordinate system and generates a two-dimensional game image. Image data corresponding to the two-dimensional game image generated is stored in a VRAM built in the image generating section  180 . In the communication game system according to this embodiment, it is possible to play a competitive car race game. The respective objects in the three-dimensional game space include a vehicle serving as a player-character to which a player gives an action instruction by operating the game terminal  10  serving as an own apparatus and vehicles serving as opponent characters (the other characters excluding the player-character) to which the other players give action instructions by operating the other game terminals  10 .  
      The image output section  182  outputs video signals to the display  210  of the television monitor apparatus  200  by reading out image data, which are generated by the image generating section  180  and stored in the VRAM, in an order of scanning and converting the image data into NTSC signals. The audio output section  184  converts various sound data outputted from the game computing section  110  into analog audio signals and outputs the audio signals to the speaker  220  in the television monitor apparatus  200 .  
      The disk reading section  188  is for reading various data stored in the DVD-ROM  190  inserted therein. A communication game program including image data necessary for displaying high-definition graphics is stored in the DVD-ROM  190 . The disk reading section  188  sends the communication game program read from the DVD-ROM  190  to the game computing section  110 . In this embodiment, the DVD-ROM  190  is used to record the communication game program and the like. However, other recording media such as a CD-ROM, a ROM cartridge and a memory card in which a semiconductor memory is used, and a hard disk device may be used.  
      The game computing section  110  includes a game processing section  120 , a movement calculating section  130 , a transmission-data storing section  140 , a reception-data storing section  142 , a transmitting section  144 , a receiving section  146 , and a communication-frequency setting section  150 .  
      The game processing section  120  performs processing for progress of the car race game according to this embodiment. The movement calculating section  130  calculates movements of respective vehicles serving as three-dimensional objects participating in the car race game (including both the vehicle serving as the player-character corresponding to the game terminal  10  operated by the player and the vehicles serving as the opponent characters corresponding to the other game terminals  10 ). This movement calculation includes computation such as movements of the other vehicles viewed from a virtual eye point position corresponding to the player and judgment of collisions between the vehicles. In this embodiment, such a movement calculation is performed by the movement calculating section  130  and other various kinds of processing necessary for progress of the car race game are performed by the game processing section  120 . However, all of these kinds of processing may be performed by either one of the game processing section  120  and the movement calculating section  130 , and the other one of the game processing section  120  and the movement calculating section  130  maybe eliminated.  
      The transmission-data storing section  140  stores game data concerning the vehicle serving as the player-character calculated by the movement calculating section  130  and game data concerning the game progress outputted from the game processing section  120  as transmission data. This transmission data is read out by the transmitting section  144  at predetermined timing and transmitted to each of the other game terminals  10  via the communication interface section  160  and the network  30 . Game data is also sent from the other game terminals  10  via the network  30 . The receiving section  146  receives the game data via the communication interface section  160  and stores the game data in the reception-data storing section  142 . The movement calculating section  130  performs the movement calculation on the basis of the data (reception data) concerning the vehicles serving as the opponent characters stored in the reception-data storing section  142 , a position of the vehicle serving as the player-character at that point in time, and the like. This movement calculation is performed at a predetermined interval (e.g., an interval of 1/60 second). However, when the reception data of the opponent characters stored in the reception-data storing section  142  is not updated at this interval, a predicted value obtained by the last movement calculation is used instead of the reception data.  
      The communication-frequency setting section  150  variably sets a communication frequency of transmitting and receiving game data between the game terminal  10  corresponding to the own apparatus and the other game terminals  10  according to contents of a game in progress. For example, the communication-frequency setting section  150  sets a communication frequency on the basis of, for example, a relative relation between the player-character and each of the plural opponent characters. Specifically, the communication-frequency setting section  150  sets a high communication frequency between the game terminal  10  corresponding to the player-character and the game terminals  10  corresponding to the opponent characters highly likely to affect an action of the player-character and sets a low communication frequency between the game terminal  10  corresponding to the player-character and the game terminals  10  corresponding to the other opponent characters. Therefore, a communication-frequency setting section  150  has the bandwidth setting section  152  and a transmission-timing judging section  154 . The bandwidth setting section  152  sets allocation of bandwidth of lines used for communication between the game terminals  10  and the network  30  via the communication interface section  160 . The lines include an uplink line used for transmitting data from the game terminals  10  to the network  30  and a downlink line used for transmitting data from the network  30  to the game terminals  10 . In this embodiment, the bandwidth setting section  152  performs processing for variably allocating bandwidth of the uplink line to each of the game terminals  10  other than the own apparatus. Since the processing for allocation of the bandwidth of the uplink line is performed in the respective game terminals  10  using the same algorithm, as a result, allocation of bandwidth is performed for the downlink line on which data is sent from the respective game terminals  10  serving as the other apparatus to the game terminal serving as the own apparatus. The transmission-timing judging section  154  judges, on the basis of the bandwidth allocated to the respective game terminals  10  by the bandwidth setting section  152 , timing for transmitting game data from the transmitting section  144  for each of the game terminals  10 .  
      The communication-frequency setting section  150  corresponds to the communication-frequency setting unit, the transmitting section  144 , the receiving section  146 , and the communication interface section  160  correspond to the communicating unit, the movement calculating section  130  corresponds to the character-action computing unit, the bandwidth setting section  152  corresponds to the bandwidth setting unit, and the transmission-timing judging section  154  corresponds to the transmission-timing judging unit. The game terminal  10  serving as the own apparatus corresponds to the communication game apparatus and the other game terminals  10  excluding the own apparatus correspond to the opponent game apparatuses (the other communication game apparatuses).  
      The competitive communication game system according to this embodiment has such a configuration. Operations of the competitive communication game system will be explained. The car race game according to this embodiment will be schematically described below.  
      (1) Any one of the game terminals  10  can request the game server  20  to hold a car race. A unit of the car race opened in response to this request is referred to as “session”. The game terminal  10  requesting to hold the car race thereafter acts as a dealer to perform processing for progress of an overall operation of the car race.  
      (2) A maximum number of game terminals  10  allowed to participate in one session is determined in advance at the time of creation of the session. Participation in the session from the other game terminals  10  is accepted until the number of game terminals reaches the maximum number during an entry period.  
      (3) The car race is performed by the game terminals  10  (players) that indicate an intention to participate in the session. As states of a player, there are three states, namely, “in a race”, “watching”, and “stand by in a lobby”. “In a race” is a state in which the player is actually participating in the car race. The player in this state actually operates the controller  300  provided in the game terminal  110  to virtually drive a vehicle. “Watching” is a state in which the player capable of participating in the car race is watching the race without participating in the race. The player in this state can watch details of the race from a predetermined camera position. “Stand by in a lobby” is a state in which, when the car race has already started, the player is waiting to participate in the next car race in the state of “in a race” or “watching”. The player in this state can learn a progress state of the entire car race (e.g., race progress is indicated by a schematic diagram).  
      (4) The game terminal  10  requests the game server  20  to hold a car race. However, after a session is created, the game terminal  10  acting as the dealer performs processing for progress of a car race game of this session. Transmission and reception of game data (e.g., positional information of vehicles serving as three-dimensional objects operated by the respective players) among the game terminals  10  in any one of the states “in a race”, “watching”, and “standby in a lobby” are performed by one-to-one communication between the game terminals  10 .  
       FIG. 3  is a flowchart showing an operation procedure mainly related to transmission of game data performed in the game terminal  10 . It is assumed that a fixed communication bandwidth is allocated to the game data to be transmitted as a result of processing by the game processing section  120 , and that bandwidth used for transmitting game data concerning the player-character calculated by the movement calculating section  130  to the game terminals  10  other than the own apparatus are variably allocated within the remaining communication bandwidth. An operation procedure for variably allocating the bandwidth is shown in  FIG. 3 .  
      The movement calculating section  130  calculates, on the basis of data concerning the vehicles serving as the respective opponent characters sent from the other game terminals  10  and stored in the reception-data storing section  142 , a position of the vehicle serving as the player-character (“the vehicle serving as the player-character” is hereinafter simply referred to as “player-character” and “the vehicles serving as the opponent characters” are simply referred to as “opponent characters”), and the like, movements of the respective vehicles serving as the player-character and the opponent characters (step  100 ). Data indicating a position of the player-character and the like obtained by this calculation is stored in the transmission-data storing section  140  (step  101 ).  
      The bandwidth setting section  152  calculates distances between the player-character and the respective opponent characters (step  102 ). For example, linear distances between a center coordinate of the player-character and center coordinates of the respective opponent characters are calculated. The bandwidth setting section  152  calculates a usable bandwidth for each of the game terminals  10  on the basis of the linear distances calculated (step  103 ).  
       FIG. 4  is a diagram showing a specific example of the distance calculation.  FIG. 5  is a diagram showing a specific example of usable bandwidth calculated on the basis of distances shown in  FIG. 4 . In  FIG. 4 , A to E indicate five game terminals  10  that are participating in an identical session. In order to distinguish the game terminals  10  from one another, the game terminals  10  are represented as game terminals  10 A to  10 E. Each value shown in  FIG. 4  indicates a distance between the player-character and each of the opponent characters corresponding to game terminals  10 , respectively. For example, when attention is directed to the player-character corresponding to the game terminal  10 C, distances ( 30 ,  15 ,  40 , and  10 ) between the player-character and opponent characters corresponding to the game terminals  10 A,  10 B,  10 D, and  10 E, respectively, are calculated by the bandwidth setting section  152  of the game terminal  10 C. The bandwidth setting section  152  of the game terminal  10 C sets, according to the distances between the player-character and the respective opponent characters, usable bandwidth corresponding to the game terminals  10 A,  10 B,  10 D, and  10 E such that, for example, there are more usable bandwidth for the closer game terminals.  
      The game terminal  10 C shown in  FIG. 4  is specifically explained as follows. As shown in  FIG. 5 , it is assumed that a bandwidth of 64 kbps is secured as a bandwidth usable for transmitting game data from the game terminal  10 C to the other game terminals  10 A,  10 B,  10 D, and  10 E. It is assumed that, in the bandwidth of 64 kbps, an area of 14 kbps indicated by F is fixedly used for transmitting a result of processing by the game processing section  120  and the like and the remaining bandwidth of 50 kbps is usable for transmission of game data obtained as a result of the calculation by the movement calculating section  130  and is allocated to the other game terminals  10 A,  10 B,  10 D, and  10 E.  
      The bandwidth setting section  152  of the game terminal  10 C performs processing for dividing the remaining bandwidth (50 kbps) at a ratio proportional to inverses of the distances to the respective opponent characters. As shown in  FIG. 4 , since the distances from the player-character corresponding to the game terminal  10 C to the respective opponent characters corresponding to the other game terminals  10 A,  10 B,  10 D, and  10 E are  30 ,  15 ,  40 , and  10 , processing for allocating the remaining bandwidth at a ratio of 1/30:1/15:1/40:1/10 is performed. As a result, as shown in  FIG. 5 , bandwidths of 7 kbps, 15 kbps, 6 kbps, and 22 kbps are allocated to the game terminals  10 A,  10 B,  10 D, and  10 E, respectively.  
      The transmission-timing judging section  154  performs, for the game terminal  10  that is one of destinations to which the game data is transmitted, processing for accumulating the usable bandwidth calculated in step  103  (step  104 ). For the game terminal  10 C, there are the game terminals  10 A,  10 B,  10 D, and  10 E that are destinations to which the game data is transmitted. The accumulation of the usable bandwidth is performed for, for example, the game terminal  10 A among the game terminals. The transmission-timing judging section  154  judges whether the accumulated value has exceeded a capacity of the transmission data (step  105 ).  
      For example, it is assumed that a capacity necessary for transmitting data obtained as a result of the calculation by the movement calculating section  130  is 60 bytes. It is also assumed that the operations shown in  FIG. 3  are repeated at an interval of 1/60 second, which is an interval for updating a game image. In other words, when it is attempted to transmit data of 60 bytes at the interval of 1/60 second, a bandwidth of 60×8×60=28 kbps is required. The transmission-timing judging section  154  judges whether the accumulated value has exceeded 28 kbps which is necessary for transmission of the game data. When the accumulated value has exceeded 28 kbps, affirmative judgment is performed in the judgment instep  105 . Then the transmission-timing judging section  154  sends a transmission instruction to the transmitting section  144 . In response to this transmission instruction, the transmitting section  144  reads out game data stored in the transmission-data storing section  140  at that point and transmits the game data to the game terminal  10 A (step  106 ). Thereafter or, when the accumulated value has not exceeded the capacity necessary for data transmission, after negative judgment is performed in step  105 , the transmission-timing judging section  154  judges whether there are the other destination game terminals  10  to which the game data is transmitted (step  107 ). When there are the other game terminals  10  (as described above, when presence or absence of transmission is judged only for the game terminal  10 A, there are the other game terminals  10 B,  10 D, and  10 E), affirmative judgment is performed. The transmission-timing judging section  154  returns to step  104  and the same processing is repeated for the other game terminals  10 . When presence or absence of transmission is judged for all the destination game terminals  10 A,  10 B,  10 D, and  10 E, to which the game data is transmitted, and a transmission operation for the game terminals  10  meeting condition for transmitting the game data is completed, negative judgment is performed in the judgment in step  107 . A series of data transmission operation performed at the interval of 1/60 second is completed.  
       FIGS. 6A and 6B  are diagrams showing specific examples of the data accumulation operation (step  104 ) and the transmission-timing judgment operation (step  105 ). As described above, the bandwidth of 28 kbps is required for transmission of the game data. It is assumed that the bandwidth setting section  152  of the game terminal  10 C has allocated 7 kbps as a usable bandwidth corresponding to the distance “ 30 ” to the opponent character corresponding to the game terminal  10 A at certain timing. In case where an accumulated value to that point in time is “ 0 ”, as shown in  FIG. 6A , an accumulated value at that time is 7 kbps. Since the accumulated value has not exceeded the data quantity 28 kbps, which is the condition for data transmission, the game data is not transmitted to the game terminal  10 A at this point in time.  
      It is assumed that, when the distance between the game terminal  10 C and the opponent character corresponding to the game terminal  10 A suddenly decreased to “ 10 ” at the next timing after the elapse of 1/60 seconds, the bandwidth setting section  152  of the game terminal  10 C allocated 22 kbps as a usable bandwidth corresponding to this distance “ 10 ”. Since the accumulated value to that point is “7 kbps”, as shown in  FIG. 6B , an accumulated value at that point becomes 7+22=29 kbps, which exceeds the condition, the data quantity of 28 kbps, at this point in time. Thus, the game data is transmitted to the game terminal  10 A at this timing. Although the accumulated value is reset once the data is transmitted, a value of the accumulated value exceeding 28 kbps at the time of transmission (1 kbps in the example shown in  FIG. 6B ) is used as an initial value of the accumulated value after being reset.  
      As described above, in the communication game system according to this embodiment, in performing transmission and reception of game data between the game terminal  10  serving as the own apparatus and the game terminals  10  serving as the plural opponent game apparatuses, it is possible to set a communication frequency for each of the apparatuses according to contents of a game. This makes it possible to increase a frequency of acquiring game data concerning a part of opponent characters according to importance or the like, prevent actions from becoming unnatural by improving accuracy of prediction of the actions, and improve the feeling of realistic sense of the game. In particular, it is possible to reduce an interval of acquisition of game data concerning opponent characters having a close relative relation with the player-character and likely to affect an action of the player-character, specifically, opponent characters present near the player-character, to reduce a degree of an impression that actions become unnatural. Further, for the other opponent characters, it is possible to reduce a data quantity of transmitted and received game data by extending an interval of acquisition of data.  
      Since the limited communication bandwidth is variably allocated to each of the game terminals  10  to effectively use the communication bandwidth, it is possible to secure a relatively large bandwidth for opponent characters having a relatively close relation and to realize prompt data acquisition.  
      The invention is not limited to the embodiment described above. Various modifications are possible without departing from the scope of the invention. For example, in the embodiment, the allocation of bandwidth proportional to inverses of distances among the respective characters is performed. However, since a wider bandwidth has to be secured for shorter distance, the allocation of bandwidth may be proportional to inverses of squares of the distances or proportional to inverses of roots of the distances. Further, the distances may be classified into plural stages to allocate the same bandwidth to the game terminals  10  corresponding to the opponent characters classified into the same stage.  
      In the embodiment, it is assumed that a capacity of the game data transmitted to the respective game terminals  10  as a result of the calculation by the movement calculating section  130  is fixed (60 bytes). However, this value maybe set larger as a distance is smaller and set smaller as a distance is larger. It is also assumed that a total bandwidth usable for data transmission to all the game terminals  10  is fixed (at 64 kbps) However, since this value is changeable according to an environment of connection to the network  30  and the like, the value of the bandwidth may be variably set at a time when all the game terminals  10  participating in a session are determined. For example, a communication bandwidth may be set for each session by, for example, actually transmitting and receiving a fixed quantity of data to measure a bandwidth or checking an upper limit value of bandwidth usable for the respective game terminals  10 .  
      In the embodiment, a communication frequency is set according to a distance between the player-character and the opponent character. However, when a degree of cooperation between the player-character corresponding to the game terminal  10  serving as the own apparatus and the opponent characters corresponding to the other game terminals  10  is set according to game contents, the communication-frequency setting section  150  may set a communication frequency taking into account the degree of cooperation. For example, when the degree of cooperation is increased by, for example, forming a group of specific players (the player-character and a specific opponent character), it is possible to increase a communication frequency for the game terminal  10  corresponding to this opponent character. If the degree of cooperation is represented by a numerical value, it is possible to perform allocation of bandwidth by the bandwidth setting section  152  in the same manner as allocating the distances among the characters.  
      When parameters indicating individualities of the respective opponent characters are set in the opponent characters, the communication-frequency setting section  150  may set a communication frequency according to details of the parameters. For example, it is possible to acquire game data at a high communication frequency for a vehicle (corresponding to an opponent character) that has a high ability value and is capable of running quickly.  
      In the embodiment, the invention is applied to the competitive communication game system for playing a car race game. However, it is also possible to apply the invention to competitive communication game systems for playing games other than the car race game.  
      In the explanation of the embodiment, game data obtained as a result of the calculation by the movement calculating section  130  is transmitted to the respective game terminals  10 . However, the same explanation applies when game data as a result of processing by the game processing section  12  is transmitted to the respective game terminals  10 . For example, since it is unnecessary to transmit this game data frequently, an arrow bandwidth (which may be fixed) only has to be allocated to the respective game terminals  10 . This makes it possible to substantially decrease a communication frequency (e.g., an interval of one second).