An optical line terminal receives an optical signal transmitted by time division multiple access from plural optical network units among which are an optical network unit performing communications at a first bit rate and an optical network unit performing communications at a second bit rate. The optical line terminal includes a branching unit, a first receiving unit, and a second receiving unit. The branching unit branches the optical signal into branches, at an asymmetrical branching ratio. The first receiving unit receives a branch having the first bit rate, among the branches of a greater branched proportion. The second receiving unit receives a branch having the second bit rate, among the branches of a lesser branched proportion.