Patent ID: 8615169

Claim:
A PON system comprising: an optical line terminal including n sections of termination processing units from a first section to an nth (a natural number equal to or larger than 2) section; m (m is a natural number) of subscriber home apparatuses; and an n:M (M is a natural number greater than m) optical splitter that splits a line for each of the sections of the optical line terminal into lines connected to the subscriber home apparatuses, wherein the optical line terminal performs transmission to optical network units using a light signal having a wavelength different for each of the sections, and allocates communication time to data, which is transmitted from the optical network units, in a time division manner for each of the sections, selects, for each of the optical network units, a section for performing data transmission, and transmits the data using a light signal having a wavelength corresponding to the selected section, at least part of the m subscriber home apparatuses include n of optical network units, each corresponding any one of i=1 to i=n, ith optical network unit includes: ith blocking filter that removes a component other than a component in a predetermined wavelength band, which is set to correspond to an ith (a natural number from 1 to n) section, from a light signal received from the line split by the optical splitter and uses a result of the removal as an ith signal; and ith PON processing unit that applies termination processing to the ith signal and transmits the data in a communication time band allocated to the ith section based on an allocation result of the optical line terminal, and the PON system is made redundant such that a number of lines between one of the optical splitter and the m of subscriber home apparatuses is larger than m.