Electronics and Telecommunications Research Institute

Korea Telecom

Bin-Yeong Yoon

Bong-Tae Kim

Sung-Chang Kim

Geun-Yong Kim

Bong-Kyu Kim

Mun-Seob Lee

Dong-Soo Lee

Hark Yoo

Yool Kwon

Kwang-Ok Kim

Yong-tae Kim

Kyeong-Hwan Doo

Jong-Deog Kim

Man-soo Han

Whan-Woo Kim

Mi-Jung Yang

Yeon-Kwae Jeong

According to a method of reducing power in an optical access network, upon the application of power, an optical network terminal (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 optical line terminal (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. If the requirements are satisfied, the ONT transmits a wake-up signal to the OLT and switches to the activation mode for normal operation.

Method of saving power in optical access network

A passive optical network system includes: a plurality of optical signal splitter receiving optical signals from a plurality of optical network units (ONUs) to provide a plurality of upstream optical signals having different wavelengths; a hybrid optical filter multiplexing the plurality of upstream optical signals in a wavelength division multiplexing (WDM) scheme; and an optical line terminal (OLT) receiving the multiplexed upstream optical signals in a time division multiplexing (TDM) scheme. Therefore, the network system can be easily expanded when the number of subscribers increases, and the optical loss can be minimized.

Passive optical network system and optical signal receiving method thereof

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.

Automatic optical power control method for OLT in PON

Provided are an optical output power control method that provides optical communication without harming the human body even when a transmission line is cut or no optical network unit (ONU) accesses a communication system, and a passive optical network (PON) system using the method. In the method, an optical signal having a predetermined period is transmitted when an optical communication system is in an abnormal state, wherein the predetermined period includes a laser-on time interval in which the optical signal has a normal power level and a laser-off time interval in which the optical signal is off or has a power level lower than the normal power level, so that the optical communication system performs optical communication without harming the human body even during the abnormal state.

Method of controlling optical output power and passive optical network system using the same

A dynamic bandwidth allocation (DBA) device and a method thereof are provided. In the DBA method, the band allocation periods according to class queues and allocable bands with respect to each class queue are calculated on the basis of the service level agreement information and stored according to the service types in separate tables. The bandwidth allocation amount is calculated with respect to class queues which have the allocation periods by concurrently checking all the tables at each frame. The upward bandwidth usage efficiency is improved by calculating the final bandwidth allocation information from the service with a high priority order on the basis of the total allocable bandwidth of the corresponding frame. The upward bandwidth allocation amount can be calculated at each frame by reducing the processing speed in calculating the bandwidth allocation amount of each class queue. Accordingly, it is possible to effectively use the network.

Dynamic bandwidth allocation device for an optical network and method thereof

A VC merging apparatus and a method of establishing or terminating connection as well as a recording medium storing instructions for embodying the same method are disclosed. The method of establishing/terminating connection includes the steps of; a) determining a kind of connection with reference to connection parameters according to an order of connection establishment or termination from a central controller; b) establishing/terminating a multi point-to-point connection based on ingress/egress connection labels, if the kind of the connection is a VC merging connection; and c) establishing/terminating a point-to-point connection based on the ingress/egress connection labels, if the kind of the connection is a non-VC merging connection.

VC merging apparatus and method for establishing/terminating connection thereof

Growing community of inventors

Daejeon, South Korea

Bin-Yeong Yoon