| 摘要 |
PURPOSE:To quicken response to a request from a terminal device, by deciding on only terminal devices which are powered on among numbers of terminal devices as objectives of polling. CONSTITUTION:A center 100 and terminal devices 200 are connected mutually through a coaxial cable 300 and a two-wave distributor 400. Only terminal devices which are powered on among the terminal devices 200 are registered to the CATV center 100. The center 100 receives a signal indicating a request from a terminal device 200 at its head end 10 and also sends a control signal and a television signal meeting its requirements. If there is data to be sent from, for example, a terminal device 102 to the center 100, this data is stored in a computer 201 temporarily. When the polling of the center 100 is performed, the signal is supplied to the computer 201, which discriminates whether the polling is address to the computer 201 or not. When the terminal device 102 is placed in a polling state in some period, the stored data is sent to the center 100 in the following period and the center 100 regards the data as data from the terminal device 102 to perform prescribed processing. |
