The invention relates to an optical access telecommunication network using the O-CDMA multiplexing comprising at least one local exchange unit (LE) being connected with a variety of network terminals (NT) via a passive optical network which has a splitting/combining unit for downstream splitting up the data traffic to be received by the respective network terminals (NT) and for upstream combining the signals transmitted from the network terminals (ONU/NT) into one single data stream to be received by the local exchange unit. Passive optical filter means (OCF) are arranged between the splitting/combining unit and the network terminals (NT), the filter means using individual codes each of which being allocated to a respective network terminal (NT), thus filtering out the data traffic exclusively associated with the respective network terminal (NT).