摘要:
The present invention provides an apparatus and method for preserving a frame sequence and distributing traffic in a multi-channel link, which efficiently distributes frame traffic while preserving the transmission sequence of frames in a link composed of multiple channels, and to a multi-channel transmitter using the apparatus and method. The present invention determines whether the preservation of a sequence of frames is required using information about received frames, predicts a frame transmission service finish time on the basis of the length of frames if the sequence preservation is required, determines a sequence preservation service time (SPST) on the basis of the predicted transmission service finish time, stores the frames in a sequence preservation buffer for the SPST, and distributes the frames to idle transmitters at a termination point of the SPST, thus maximizing the efficiency of channel use.
摘要:
The present provides a method of dynamically managing multicast groups and allocating multicast service wavelengths for the highest channel efficiency. According to the present invention, the share indices of wavelengths of all multicast service groups, which employ broadcasting wavelengths and data wavelengths, are periodically ascertained on the basis of IGMP snooping-based technology in a WDM-PON. Based on the ascertainment results, if the channel share index of the group that employs the broadcasting wavelength is smaller than the channel share index of the group that employs the data wavelength, the share index of the wavelength of the multicast group that employs the broadcasting wavelength is maximized by dynamically changing allocation of the wavelength of the multicast group, so that a maximum multicast service can be provided within limited resources.
摘要:
A termination device for use in a WDM-SCM PON system can effectively support a multi-channel integration function of a WDM/SCM PON system. The termination device contained in a termination end of a WDM/SCM (Wavelength Division Multiplexing/Sub-Carrier Multiplexing) PON (Passive Optical Network) to connect the PON with either a subscriber or an Ethernet service network includes: an Ethernet interface module connected to the Ethernet service network or the subscriber to perform an Ethernet interface function; a WDM/SCM physical layer module physically connected to the WDM/SCM PON to transmit/receive optical signals to/from the WDM/SCM PON; and a MAC (Media Access Control)-bridge module for performing a multiplexing/demultiplexing operation based on a MAC address upon receipt of transmission/reception frames, and reconstructing preambles of the frames while being classified according to channels so that individual Ethernet frames are matching-processed while being classified according to SCM channels of the WDM/SCM physical layer module.
摘要:
Provided is a fast stochastic decoding method for a low density parity check (LDPC) code. The decoding method may include decoding the LDPC code based on an LDPC decoding scheme, using a message expressed by a log-likelihood ratio (LLR) value.
摘要:
Disclosed herein is a system for providing dynamic service using optical sub-carrier multiplexing type multi-channel access and method of controlling the same. The system includes a plurality of optical sub-carrier multiplexing modems, an optical gigabit-Ethernet switch and a plurality of wavelength division multiplexing couplers. The optical sub-carrier multiplexing modems transmit user traffic using multiple optical sub-carrier channel control. The optical gigabit-Ethernet switch is connected to an access network upstream and to the optical sub-carrier multiplexing modems downstream to manage a plurality of wavelengths and a plurality of optical sub-carrier channels according to the wavelengths. The wavelength division multiplexing couplers connect the plurality of optical sub-carrier multiplexing modems with the optical gigabit-Ethernet switch, perform aggregation and branching of a certain wavelength and transmit it.
摘要:
The present invention relates to a WDM/SCM-PON and a media access control method for asymmetric packet communication in the same. In the WDM/SCM-PON, each SCM channel is classified and used as a link by adopting an SCM technique of subdividing a wavelength band of up/downstream data links between an OLT and ONTs into frequency bands, and the ONTs are formed so that a certain SCM channel is independently distributed not fixedly assigned. Accordingly, an inventory problem, which can be generated in WDM/SCM, is prevented before happens, asymmetric dynamic band allocation is performed, and asymmetric service of up/downstream transmission is supported. As a result, a band required for next generation service is dynamically provided, optical interference effect is minimized, and Ethernet compatibility is provided so that Ethernet service suitable for providing IP service can be accommodated.