FIELD: telecommunications, in particular, upstream signal transmission. SUBSTANCE: method involves modulation of carrier frequency electric signal using DPSK method, modulation of intensity of output light using said modulated electric signal. Upon upstream transmission of signals, output light is modulated by amplitude by, preferably scrambled, NRZ main band signal. Carrier frequency signal is derived by multiplication of frequency of recovered signal of receiving circuit of node. EFFECT: transmission of upper frequencies, simplified recovery of clock pulses, increased speed of operations of receiver of central node. 11 cl, 1 dwg
