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:
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:
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 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.
摘要:
Provided are extendable loop-back passive optical network (PON) and scheduling method and apparatus for the same. The loop-back type PON includes an OLT (optical line terminal) including a wavelength-tunable optical transmitter and a wavelength-locked optical receiver, and an RN (remote node) including an optical coupler/splitter, the optical coupler/splitter receiving optical signals from the wavelength-tunable optical transmitter and splitting the optical signals by wavelength so as to transmit the optical signals to corresponding ONTs (optical network terminals). Each of the ONTs transmits upstream data to the OLT using the same wavelength as the wavelength of the optical signal received from the OLT through the RN. Since the optical network makes use of the TDM and WDM communication schemes, the optical network can be maintained and upgraded at lower cost.
摘要:
Provided are a physical coding sublayer (PCS) apparatus and an Ethernet layer architecture for a network-based tunable-wavelength passive optical network (T-PON) system employing an Ethernet communications technology, and more particularly, to a PCS apparatus and an Ethernet layer architecture for supporting a series of initialization function of allocating wavelengths between an optical line terminal (OLT) and an optical network terminal (ONT) and arranging the allocated wavelengths. A PCS layer transmits and allocates wavelength information such that wavelengths for setting a link between an OLT and an ONT are allocated, optical wavelengths within the ONT are observed while a system operates to allow continuous control so that operating of the system can be stably maintained.
摘要:
Provided is a method of increasing the number of subscribers using a time division duplexing (TDD) technology in a wavelength division multiplexing (WDM)/Ethernet passive optical network (WE-PON) system, and more particularly, a method of increasing the number of subscribers admissible per wavelength using a TDD technology. In an existing WE-PON, due to an amplitude squeezing effect (ASE) in an optical network terminal (ONT) and an optical output power restriction in an optical line terminal (OLT), there is a disadvantage in that 4 or more subscribers cannot be simultaneously accommodated per wavelength. However, the present invention enables accommodation of a maximum of 16 subscribers per wavelength by applying a TDD technology to a medium access control (MAC) protocol. Point-to-multipoint services can be provided without the need of an additional header for classifying upstream and downstream window sizes in a downstream bandwidth used in an existing WDM-PON loopback technique using dynamic band allocation (DBA) applied to a conventional E-PON MAC protocol and scheduling algorithm. In addition, a DBA and threshold adjustment mechanism are provided to compensate for a downstream bandwidth decrease caused by application of the TDD technology.