Patent ID: 11956009
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. An optical communication method in a passive optical network (PON) in which an optical path laid in a ring topology, the optical communication method comprising:
outputting an optical signal to the optical path so that the optical signal is transmitted on the optical path in at least one of a clockwise direction or a counterclockwise direction;
connecting an unequal branch optical splitter including one primary-side main port, one secondary-side main port, a plurality of primary-side branch ports, and a plurality of secondary-side branch ports, to the optical path via the primary-side main port and the secondary-side main port;
by the unequal branch optical splitter, branching the optical signal transmitted counterclockwise from the optical path, outputting optical signals obtained by branching, from the respective secondary-side branch ports at a predetermined branching ratio, branching the optical signal transmitted counterclockwise from the optical path, and outputting optical signals obtained by branching, from the respective primary-side branch ports at a predetermined branching ratio; and
receiving the optical signal from at least one of one primary-side branch port of the plurality of primary-side branch ports or a secondary-side branch port of the plurality of secondary-side branch ports corresponding to the one primary-side branch port in the unequal branch optical splitter.