Speaking of FTTH, we must first talk about fiber access. FTTH belongs to the access network part. The access network is the part from the local office or remote module to the user, which mainly completes the multiplexing and transmission functions, and generally does not include the switching function. Historically, this part was also called the local loop or subscriber loop. According to the definition of ITU-T, FTTH is the entrance of the fiber to the household. There is no copper wire between the end office and the household. The FCC in the United States defines a new meaning for the "H" in FTTH. Family, including small business establishments.