Patent ID: 8391715
Filing Date: 2013-03-05
Classification: H04B

Abstract:
1. A communication system comprising a plurality of subscriber units, and a subscriber accommodating apparatus which is connected to the subscriber units by optical fibers through a splitter; wherein: the subscriber accommodating apparatus includes: a transmitter that transmits an optical signal through the optical fibers, a first intensity control unit that changes intensity of an optical signal to be outputted frog the transmitter; a control unit that measures communication distances from the subscriber units respectively, and measures intensities of optical signals the subscriber units can receive respectively, and a frame processing unit that gives an instruction to the first intensity control unit to output an optical signal with first intensity when the optical signal is transmitted to a first group of the subscriber units which can receive the optical signal with the first intensity, and gives an instruction to the first intensity control unit to output an optical signal with second intensity when the optical signal is transmitted to a second group of the subscriber units which can receive the optical signal with the second intensity, based on measuring results of the control unit; each of the subscriber units includes: a receiver that receives an optical signal through a corresponding one of the optical fibers; a second intensity control unit that changes intensity of an optical signal to be inputted into the receiver; and a control unit that controls the second intensity control unit; the frame processing unit of the subscriber accommodating apparatus notifies each subscriber unit belonging to the first group of a timing when the subscriber unit should receive the optical signal with the first intensity, and each subscriber unit belonging to the second group of a timing when the subscriber unit should receive the optical signal with the second intensity, respectively; and the control unit of each of the subscriber units adjusts the intensity of the optical signal to be outputted to the receiver by the second intensity control unit, in accordance with the timing the subscriber unit is notified of by the subscriber accommodating apparatus.