| 摘要 |
PURPOSE:To prevent collision in a transmission line by permitting respective base stations to calculate likelihood showing certainty in radio signals received from slave stations, to decide a time based on the likelihood and to transmit the signals to a master station through the transmission line after a prescribed time. CONSTITUTION:The signals from the slave stations 21, 23 and 25 are received in respective base stations 11, 13 and 15. The reception signals are demodulated in a demodulator 37 and are supplied to a likelihood calculation circuit 35. Likelihood showing the certainty of a demodulation signal is calculated, the time based on the likelihood is waited for, and transmission is executed only when the transmission line 17 is in an used state. Thus, transmission signals from the base stations 11 and 13 are prevented from colliding. A waiting time corresponding to likelihood calculated in the circuit is decided in a time decision means provided in a LAN node processor 33. When likelihood is large, the waiting time is set short, and it is set long when likelihood is small. Thus, the base station which has received the packet signal of largest likelihood transmits the signal to the transmission line 17 fastest and the master station 20 can receive it at the largest probability. |
