Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: Entrance and exit of a person is efficiently managed by simple authentication and registration of entrance and exit using a communication terminal carried by the person.

Abstract: When the terminal 5 requests a partial access of a desired karaoke song to the center 3 in S380, only the climactic passage data of the karaoke song is transmitted from the center 3 to the terminal 5. The terminal 5 reproduces the climactic passage in S400. Then, the terminal 5 determines whether or not the user will pay for the karaoke song in S410. When the payment is confirmed, the terminal 5 requests total access to the center 3 in S340, receives the entire data of the karaoke song in S350, and reproduces the data in S360. It is possible to prevent the user from erroneously requesting a total access of a karaoke song which the user does not want to sing. It is ensured that the user can obtain karaoke songs which he/she really wants to sing, within a short period of time.

Abstract: A data transmission system includes a polling modem and a central control unit that receives a response signal from a terminal. A data transmission central control unit performs polling type transmission to transmit an information data unit to the terminal that has requested the information data unit. The central control unit also performs loop type transmission to cyclically transmit information data units with their loop flags being set to the terminals in succession. The control portion in the terminals selects the transmission that requires the shortest waiting time.

Abstract: Each of the data transmission devices 15a-15d serially and cyclically transmits all the song data over a corresponding channel, by a time cycle corresponding to the number of the song data. The four data transmission devices 15a-15d transmit the song data, at timings shifted from one another by (1/the number of channels) of the time cycle. Each terminal determines one channel out of the four channels that can most rapidly supply desired song data. Each terminal then picks up the desired song data from the determined channel.

Abstract: The memory device 13 in the center 3 stores a plurality of information data categorized in a plurality of genres. The input device 43 of the terminal 5 selects an information data desired to be obtained, out of the plurality of information data stored in the memory device 13. The control portion 41 in the terminal 5 receives the desired information data and reproduces the desired information, when the desired information data is of a genre the terminal is contracted for. The control portion 41 does not reproduce the desired information or reproduces the desired information in a manner so that the user may not obtain when the desired information data is out of the genre the terminal is contracted for.

Abstract: When a song data group of a requested song comes in the normal mode ("Yes" in S230, ) the terminal 5 picks up that song data D5 in S240. When the song data group of the requested song does not arrive ("No" in S230,) the terminal first judges in S250 whether or not it is necessary to rapidly obtain the song data of the requested song. If the terminal is presently playing a karaoke performance, it is unnecessary to rapidly obtain the song data of the requested song, and therefore the terminal waits for the song data that will come in the normal mode. If the terminal is not conducting a karaoke performance (i.e., "No" in S250), the terminal should be rapidly supplied with the requested song. When it is determined that the requested song will come soon ("Yes" in S290 or S300,) the terminal still waits for the song data that will come in the normal mode.