| 摘要 |
PURPOSE:To collect data at all terminals to a central device efficiently, by constituting a group of a terminal group and the central device which can make transmission and reception mutually to the terminal impossible of direct transmission and reception with the central device, and transferring data between terminals in the group or the central device and the terminal. CONSTITUTION:Communication with a weak radio wave can be made between terminals 1, 2, 5, 6 and 8 and a central device C, but such communication to be held directly is impossible between terminals 2, 3 and 7 and the device C. As to the terminal 2 which can not directly communicate, data is transferred to the device C via the terminal 2, as to the terminal 3, via the terminals 1 and 2, and as to the terminal 7, via the terminal 6. All the terminals are distinguished into groups ofI-V depending on the difference of the propagation path. All the terminal data can be collected by repetitively designating the terminals 1, 2, 5, 6 and 8 from the device C. |
