Abstract: Provided is an Optical Network Unit (ONU) and a method of operating the ONU. The ONU may include: a measurement unit to measure a downstream optical signal strength of downstream data received from an Optical Line Termination (OLT) via an optical splitter; a determination unit to determine an upstream optical signal strength based on the measured downstream optical signal strength; and a communication unit to transmit, to the OLT via the optical splitter, upstream data generated based on the determined upstream optical signal strength.

Abstract: Disclosed is a method of registering only an authorized optical network terminal among a plurality of optical network terminals with the same serial number, in an optical line terminal, using a public key encryption algorithm, in a Gigabit Passive Optical Network (GPON). According to an exemplary aspect, a GPON system encrypts a physical layer OAM message transmitted/received for serial number registration of an optical network terminal, using a key distributed according to a public key encryption algorithm, and authenticates registration of the optical network terminal using the encrypted physical layer OAM message. Accordingly, it is possible to securely authenticate registration of an authorized optical network terminal and block registration of unauthorized optical network terminals.

Abstract: Provided is a method of reducing power consumption of an optical access network (OAN) as much as possible by configuring an optical line terminal (OLT) and optical network terminals (ONTs) in the OAN to support a maximum power-saving mode. According to the method, upon the application of power, an ONT operates normally in an activation mode. The ONT then determines whether the requirements for switching from activation mode to power-saving mode are satisfied. If the requirements are satisfied, the ONT transmits a sleep signal to an OLT, which is a message notifying that the ONT will soon switch to power-saving mode. Thereafter, the ONT switches to power-saving mode and cuts off power for all functions except for power for monitoring and controlling external inputs. The ONT then determines whether the requirements for switching from power-saving mode to activation mode are satisfied.

Abstract: Provided are an apparatus and method for efficiently and dynamically allocating a bandwidth on a Time Division Multiple Access-based Passive Optical Network (TDMA PON).

Abstract: Provided is an automatic optical power control method for an optical line terminal (OLT) of a passive optical network (PON). The automatic optical power control method includes at the OLT, measuring an allowable range of the optical power allowing a normal network operation on the PON, at the OLT, setting an optimum optical signal level within the measured allowable range of the optical power, and at the OLT, adjusting a power level of a transmitter to the set optimum optical signal level. Accordingly, an appropriate power level can be selected depending on an optical distribution network (ODN) structure to drive the transmitter. Also, when the entire optical network units are deactivated, a laser of the transmitter is turned off to thereby minimize unnecessary power consumption at the OLT.