Abstract: An apparatus and method for detecting errors in received data and transferring only error-free data in data communications are provided. In the cyclic redundancy check (CRC) verification apparatus and method having a constant delay, irrespective of the length of a received data frame, input and output processing delay of received data is made to be constant. The CRC verification apparatus having constant delay comprises an input control unit which stores the start address of an input data frame in a memory storing the input data frame, and stores a CRC verification result in the start address location; and an output control unit which after a predetermined constant time passes from the start address, reads an input data frame and if the CRC verification result is normal, output the read data frame. The apparatus and method make the time taken for receiving a data frame, constant irrespective of the received data frame, while CRC verification is performed.

Abstract: Disclosed is a home gateway apparatus having an in-home telephone network switching function, and an embodiment method thereof. The home gateway apparatus offers high-speed access to an access network using xDSL (“x” variety of Digital Subscriber Line) protocols such as ADSL or VDSL and an in-home network using VoIP (Voice over Internet Protocol) functions and a variety of protocols, and has xDSL and VoIP interfaces with PSTN (Public Switching Telephone Network) and VoIP functions that enable easy installation and application in different in-home telephone network environments. Using this, in-home VoIP/POTS (Plain Old Telephone Service) networks and high-speed HomePNA networks can be freely constructed through a single home gateway, bypassing the existing two-wire or four-wire in-home telephone lines.

Abstract: An apparatus for managing Ethernet physical layer registers and a method thereof are provided. The apparatus comprises a central processing unit (CPU) with an external bus interface function, and an interface conversion unit which is connected to the CPU through the external bus interface, converts the external bus interface into management data input/output (MDIO) interface and performs communications with the physical layer apparatus.

Abstract: An apparatus and method for checking validity of an 8B/10B code-group are provided. The apparatus for checking validity of an 8B/10B code-group includes a 6B/5B disparity classification unit, a 4B/3B disparity classification unit, an RD6 detection unit, an RD4 detection unit, an 8B/10B code-group rule violation detection unit, an RD error detection unit, and a unit for outputting 8B/10B code-group validity. The apparatus receives an 8B/10B code-group, divides into a least significant 6-bit nibble and a most significant 4-bit nibble, detects a running disparity, and by doing so, determines the validity of a code-group. The apparatus and method for checking validity of an 8B/10B code-group relatively shortens the critical path, which indicates the number of combinational logic circuits that should be operated in a unit time, and therefore the apparatus and method are appropriate to high-speed systems such as gigabit Ethernet systems.

Abstract: A dual ring communication method using a node system includes: with congestion occurring in a first node system, the first node system generating a congestion information packet and forwarding it to an upper node system positioned in a direction opposed to a direction of forwarding a data packet; a second node system determining whether it is the last node involved in the congestion; adding its congestion information to the congestion information packet and forwarding the congestion information packet to an upper node system when the second node system is not the last node; performing bandwidth allocation for the node systems in other case; and generating a bandwidth allocation packet and transmitting the bandwidth allocation packet to the node systems involved in the congestion.

Abstract: 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.

Abstract: A method and apparatus for processing Ethernet data frames in a media access control (MAC) sublayer of an Ethernet passive optical network (PON) are provided.

Abstract: Disclosed herein is a resource allocation method for providing load balancing and fairness for a dual ring. The resource allocation method includes the step of determining whether a bandwidth allocation request message is received from one of other nodes. If the bandwidth allocation request message is received, it is determined whether one or more of two rings of the dual ring fulfill a request of the bandwidth allocation request message. If the rings fulfill the request, a path is allocated to one of the rings having a lower weighted cost. A resource allocation information notification message is provided to other nodes. If the rings cannot fulfill the request, the process ends.

Abstract: A method of controlling data transmission in an Ethernet passive optical network (EPON) and an apparatus thereof are provided. Transmission permission messages using a mode of bandwidth allocation are queued in a queuing unit according to the types of the transmission permission messages. A transmission time duration of upstream data is defined for each of the transmission permission messages queued in the queuing unit. A bandwidth allocation unit generates transmission permission messages to allocate upstream data transmission bandwidth for an optical network unit (ONU), based on the transmission permission messages stored in the storage unit. A scheduler designates the predetermined priority, reads transmission permission messages from queues according to a predetermined priority, determines a transmission start time of upstream data, and outputs the transmission permission messages.

Abstract: A method and apparatus for determining a communication path over a network are provided. The method involves generating a spanning tree having connection devices over a network as vertices and having links among the connection devices as edges; allotting predetermined vertex information to each vertex on the spanning tree; detecting all circuits having a plurality of communication paths among the connection devices over the network corresponding to the spanning tree; and applying rapid ring spanning tree protocol (RRSTP) to links corresponding to the detected circuits and applying rapid spanning tree protocol (RSTP) to links not corresponding to the detected circuits.

Abstract: The present invention provides an Ethernet switching apparatus using frame multiplexing and demultiplexing. The Ethernet switching apparatus has a plurality of frame demultiplexers, a plurality of frame multiplexers and a switch fabric chip set. The frame demultiplexers convert at least one 10 gigabits Ethernet frame into a plurality of gigabit Ethernet frames. The frame multiplexers convert a plurality of gigabit Ethernet frames into at least one 10 gigabits Ethernet frame. The switch fabric chip set is provided with input and output interfaces using the GMII, and is connected to the frame demultiplexers and the frame multiplexers in the GMII format. The switch fabric chip set outputs frames through an arbitrary usable one of a plurality of GMII ports connected to a corresponding frame multiplexer if the frames are transmitted to the corresponding frame multiplexer.

Abstract: Provided is an optical Code Division Multiple Access (CDMA) transmitting apparatus and method for transmitting bipolar data in an optical CDMA system. The optical CDMA transmitting apparatus and method of the present research has a simple structure, including only one optical CDMA encoder and one optical modulator. This technology minimizes multiple access interference by using modified pseudo-noise code in the encoding process, thus improving the optical CDMA transmission performance. The optical CDMA transmitting apparatus includes: an optical CDMA encoding means for encoding lights from the outside into a code or a complement code of the code; and an optical modulation means for transmitting the code or the complement code of the code which is selected in the optical CDMA encoding means based on the polarity (either ‘0’ or ‘1’) of the data inputted from the outside.

Abstract: The present invention provides an admission control method in an Internet differentiated service network, for dividing an admission control function executed at an ingress edge node into a path level and a link level, performing a path level admission control function at an ingress edge node without communication with a bandwidth broker by enabling the path level to use a specific bandwidth being initially allocated to a corresponding path by a bandwidth broker, and performing a link level admission control function through the use of a measurement based admission control method by enabling the link level to be allocated a bandwidth of an unused other service using a movable boundary method when the initially allocated path level bandwidth is completely used.

Abstract: The present invention presents a method for providing IP multicast service using a virtual LAN, which can provide efficient multicast service in a network by applying the virtual LAN to the IP multicast service. A method for providing IP multicast service using a VLAN in a network including an IP multicast/VLAN manager for supporting an IGMP and a GVRP, and multicast group members, comprising the steps of: after generating an IP multicast group, allowing a sender to request the IP multicast/VLAN manager to search for at least one host joining the IP multicast group; allowing the IP multicast/VLAN manager to check whether the host supports the VLAN; and allowing the sender to transfer a packet through the VLAN if the host joining the IP multicast group supports the VLAN and allowing the sender to broadcast a packet through IP multicast if not.

Abstract: The present invention provides a dynamic routing method for a multistage bus network in a distributed shared memory environment. For performing a forward or backward U-turn routing (FUR or BUR), the forward or backward-turning allowable stage, respectively for FUR or BUR, is compared with a current stage check whether a U-turn is possible in the current stage. If not affirmative, traffic levels of switches in its next or previous stage connected to a switch in the current stage are compared to each other, respectively for FUR or BUR. A switch having the lowest traffic level is selected as a route switch of the next or previous stage, and the next or previous stage is changed to a current stage, respectively for FUR or BUR. The procedure is repeated from the checking step. If affirmative, a U-turn at the current stage is performed, and a backward or forward routing is performed, respectively for FUR or BUR.

Abstract: The present invention provides a low cost implemented optical add/drop device suitable for application in a WDM based optical subscriber network that assigns a unique wavelength to each subscriber, which uses an inexpensive optical tap coupler device and an usual optical fiber Bragg grating, simplifying the configuration and manufacturing process, while having relatively high quality performance. The optical add/drop device according to the present invention uses a combination of an optical tap coupler and an optical fiber Bragg grating, instead of a combination of an optical circulator and an optical fiber Bragg grating. Therefore, the cost is 10 times lower than an add/drop device adopting the optical circulator, and the configuration is simple. In addition, the implementation is very easy because the already-existing mature components can be utilized as they are.

Abstract: The present invention provides a serial bus type configuration recognition and alarm apparatus for a system having a plurality of various boards. The apparatus of the present invention includes a plurality of first transmission units, a second transmission unit and a recognition unit. The first transmission units report board IDentifications (IDs) and board failure status information through a first serial bus. The second transmission unit is connected to the first transmission units to report the board IDs, the board failure status information and an ID thereof. The recognition unit is connected to the second transmission unit to ascertain the configuration and failure status of the boards and report received board IDs and board failure status to a terminal.

Abstract: An apparatus for providing quality of service (QoS) of voice over IP (VoIP) traffic on IP routers and a forwarding method therefor are provided. The VoIP quality of QoS providing apparatus in an Internet protocol (IP) network containing data traffic and providing VoIP service includes: a softswitch which performs a VoIP call coordination function in the IP network and transmits VoIP call connection information in a multicast transmission method; and a router which provides QoS in forwarding a VoIP packet, by using the information received from the softswitch. With the VoIP QoS service providing apparatus, reliable multicast transmission method is enabled in providing VoIP connection information to each router, and when a softswitch additionally processes related functions, the load to the system is reduced. Since in the router, VoIP QoS flow and QoS information are added to a flow table for performing packet forwarding, VoIP packet recognition and QoS providing are enabled.

Abstract: An apparatus, a method and a storage medium for carrying out a deskew among multiple lanes for use in a division transmission of large-capacity data.

Abstract: A router for supporting differentiated qualities of service (QoS), and a fast Internet protocol (IP) packet classification method performed in the router, are provided. The router hierarchically divides a memory having flow tables into a fast internal cache memory and an external typical memory. The internal cache memory stores recently searched table entries. The router preferentially searches the flow tables of the internal cache memory. Only when the internal cache memory searching fails, the flow tables of the external memory are searched. Consequently, the frequency of interactions between a packet classifier and the external memory decreases to improve the speed of packet classification.