MAIN STATION-SIDE APPARATUS, SUBSTATION-SIDE DEVICE, CENTRAL STATION, AND OPTICAL COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To allow the use of a plurality of OLTs, allowing an optical fiber to be lent by branch by making different communication companies provide services using their own independent OLTs and to reduce the effects of services on each other to facilitate management, in consideration that only one OLT can be normally installed in a PON system sharing the optical fiber among a plurality of subscribers and accordingly it is difficult that the optical fiber is lent to other communication companies by branch. SOLUTION: In a PON system wherein a main OLT 11 includes one or more subordinate ONUs, a sub-OLT 12 is provided besides the main OLT 11 and is provided also with one or more subordinate ONUs to the sub-OLT 12 and they can be accommodated in one PON system. Accordingly, for example, when the main OLT 11 is installed by a communication company A and the sub-OLT 12 is installed by a communication company B, lending the optical fiber from the communication company A to the communication company B by branch can be effectively performed. COPYRIGHT: (C)2010,JPO&INPIT