| 摘要 |
PURPOSE:To make the multiple use of a network possible without requiring a carrier detecting circuit by transmitting a packet of a base band to retrieve usable channels. CONSTITUTION:At a transmission time, a control part 20 of a transmitting station selects a used channel (n) (CHn) and transmits it as a packet to a network 10 through a base band transmitting part 21. After transmission, only when a transmission inhibiting packet or a negative acknowledge (NAK) from another transmitting station is not received within a prescribed time by a base band receiving part 22, a modulating and transmitting part 23 is set to the CHn by a channel select line 24, and data is transmitted through the modulating and transmitting part 23. If another transmitting station uses the CHn when said transmission request is performed, this transmitting station transmits the inhibiting packet or the NAK preferentially to the other packets to assert his use right of the CHn. The packet having the constitution shown in the figure is used for this channel retrieval, and addresses of all other transmitting stations are put in the field of a destination address 31, and a desired channel is put in the field of data 35. |
