| 摘要 |
PURPOSE:To shorten time for communication by speedily acquirring a channel by selecting any data channel with high idleness probability concerning the modem for specified small power radio transmission to perform communication while selecting any idle channel out of plural data channels at random. CONSTITUTION:When a data channel CHA selected at random is provided with a carrier when it is not idle at the time of data channel selection (line connection), a CPU 3 (a high idleness probability data channel selecting means 3A of the CPU 3) adds '1' to the number 4B of data channels provided with carriers of that channel CHA. This addition is continued for a prescribed term (unusable data channel refresh interval) 5B and when the number 4B of times reaches an unusable data channel deciding reference value 5C, this data channel CHA is registered as an unusable data channel 4C and excluded from the selecting objects of channels thereafter. In this case, however, the data of the number 4B of times and the channel 4C are cleared after the lapse of the prescribed term 5B, and a data channel selecting operation similar up to the moment is repeated from the biginning. |
