Method and arrangement for transmitting signals in a point to multipoint network

Bidirectional data signals are exchanged between a central unit (OLT) and a plurality of network terminals (ONU1 - ONU10). The optical carrier frequencies of the downstream and upstream signals are chosen that reflections do not interfere with the selected signal at the optical network unit and not with the received upstream signals at the central unit. The optical network units select their associated downstream signal and generate an associated upstream signal.