Abstract: A light concentrator for an optical antenna gradually narrows from the light receiving end to the end in contact with a light detector, and has a refractive index that gradually increases from the first to the second end, to afford a greater acceptance angle for the incoming optical signal. The increase may occur in stages of corresponding layers of the light concentrator, the layers being arranged in order of increase in refractive index from the first end to the second end.

Abstract: A method and system is disclosed that can support communications among devices contained in different piconets in a high-speed Wireless Personal Area Network. The high-speed WPAN includes a parent piconet, a newly designated child piconet using time slots allocated among devices in the parent piconet, and a bridge device which is located in the child piconet, that broadcasts information about the devices of the parent piconet and the child piconet to the devices included in the high-speed WPAN, and operates to perform a data transfer between a device in the child piconet and a device in the parent piconet. A media access control (MAC) frame structure that includes an overall capability field for indicating an overall capability of a specific device, a length field for indicating a length of a frame, and an element identifier (ID) field for identifying respective elements is used by the bridge device to facilitate communications.

Abstract: Disclosed is a frame structure in a high-speed wireless personal area network (WPAN) and a message transmitting method thereof which enable communications among devices existing in different piconets by using a device that provides a bridging function in the IEEE 802.15.3 WPAN. In a high-speed WPAN system which includes a parent piconet having a plurality of devices and a child piconet using time slots allocated by the devices located in the parent piconet, and a bridge device located in the child piconet, that broadcasts information about the devices of the parent piconet and information about the devices of the child piconet to the devices included in the high-speed WPAN, and operates to perform a data transfer between a first specified device in the child piconet and a second specified device in the parent piconet.

Abstract: A device and method to monitor and temperature compensate change in wavelength within a WDM optical communication system is disclosed. The device includes a laser diode for generating an optical signal for temperature monitoring, a first fiber Fabry-Perot interferometer sensor unit for generating a first sensor signal according to temperature by means of the optical signal, and a processor for monitoring temperature by means of the first sensor signal and an externally provided second sensor signal and equalizing waveforms of the two sensor signals with each other. The externally provided second sensor signal is provided by a remote node that includes a second fiber Fabry-Perot interferometer sensor unit for receiving the optical signal for temperature monitoring to generate the second sensor signal according to temperature, and a waveguide grating router unit for transmitting the second sensor signal to the optical line terminal.

Abstract: A method for effectively implementing real time multimedia data transmission in an Ethernet network that operates in a CSMA/CD (Carrier Sense Multiple Access/Collision Detect) scheme. Real time data gets priority over general data, and uses an MPCP (Multi-Point Control Protocol) of the IEEE 802.3ah EPON to prevent a collision from occurring in real time data transmission, and also prevents delay time variation. An RT-IFG (Real Time Inter-Frame Gap) is defined for real time data, shorter than an IFG, to give priority to the real time data over general Ethernet data. The MPCP is used for transmission of real time data without collision between the real time data.

Abstract: A high-speed WPAN (Wireless Personal Area Network) system for enabling communication between piconets is configured by at least one first device located in the child piconet. A C-PNC (Child Piconet Coordinator) device includes a C-MIB (Child Piconet Management Information Base) stores mapping information associated with devices located in the child piconet and a P-MIB (Parent Piconet Management Information Base) stores mapping information associated with devices located in a parent piconet. At least one second device is located in the parent piconet. The first device includes a C-MIB and a first B-MIB (Bridging Management Information Base), detects destination information of data using the mapping information stored in the first B-MIB to transmit data to a device located in the parent piconet, and transmits the data containing the detected information to the C-PNC device.

Abstract: A high-speed WPAN (Wireless Personal Area Network) system for extending a service area includes an optical fiber serving as a medium for transmitting data; a plurality of pico-nets each including a plurality of devices and a PNC (Pico-Net Coordinator) device for managing the devices; a plurality of two-way signal converters corresponding to the pico-nets, each of the signal converters adapted for converting an optical signal received from the optical fiber into an electrical signal to transmit the electrical signal to the pico-nets, and for converting an electrical signal received from each of the pico-nets into an optical signal to transmit the optical signal to the optical fiber. A plurality of connectors are attached to the optical fiber and the signal converters for transmitting signals input from the optical fiber and the signal converters bidirectionally.

Abstract: A multicast transmission method in GEM mode in Gigabit-capable passive optical network and a method of processing frames. The multicast transmission method includes the steps of: (a) setting a multicast connection; and (b) transmitting multicast messages in a GEM mode, wherein said step (a) includes a first sub step (i), in which predetermined ONTs are registered to a multicast group by means of IGMP frames in the first step, and a second sub step (11), in which an OLT assigns a multicast port ID to the multicast group and the ONTs registered to the multicast group. In addition, step (b) includes a first substep (i), in which the OLT assigns a multicast port ID to a message transmitted from a router to the multicast group, and transmits the message, and a second sub-step (ii), in which an ONT, which belongs to the OLT, filters the message, to which the multicast port ID is assigned, by means of a port ID assigned to the ONT.

Abstract: A GEM OAM frame transmission method used in a Gigabit-capable passive optical network is provided. The method defines an OAM frame structure in a GEM mode of the Gigabit-capable passive optical network and enables an OAM to be achieved even when the GEM mode is operated. The method comprises the steps of: constructing a GEM OAM frame including a GEM header field and a GEM payload field, the GEM header field containing OAM representation information indicating that the GEM OAM frame contains the OAM information, the GEM payload field containing the OAM information; and transmitting the constructed GEM OAM frame in order to enable the ONU/ONT to perform an operation according to the OAM information.

Abstract: A GTC frame Structure and a method for transmission of ONT management control information in GPON. The method comprises the steps of: constructing a GTC frame which includes a PCBd portion having an OMCC field including either destination identifier information for supporting a GEM mode or destination identifier information for supporting a ATM mode, and a payload portion including data; and transmitting the GTC frame. The GTC frame structure for ONT management control information transmission can transmit the management control information to an ONT supporting either ATM mode or GEM mode.

Abstract: An optical network terminal (ONT) management control protocol of gigabit-capable passive optical network. A gigabit-capable passive optical network encapsulation method (GEM) frame structure that supports delivery of ONT management control information for an optical network unit (ONU) using a GEM and a method for processing data using the GEM frame structure. The GEM frame structure includes in the GEM header a payload type of the GEM header frame, and is used for a gigabit-capable passive optical network (GPON), wherein payload type information, which represents a data type of a payload portion of the GEM frame, is displayed in a header of the GEM frame, in order to provide a GEM control frame which delivers management control information transferred from an OLT (Optical Line Termination).

Abstract: A method and apparatus for transmitting data from an optical network unit (ONU) to an optical line termination (OLT) in a Gigabit Ethernet passive optical network (GE-PON) on the basis of a time division multiple access (TDMA) scheme are provided. A measurement of a data transmission time when the data is transmitted to the OLT is obtained, and the measured data transmission time is compared with a predetermined normal transmission time. The transmission of the data is maintained if the measured data transmission time is determined to be less than or equal to the normal transmission time from the comparison result. However, if the measured data transmission time is determined to be greater than the normal transmission time, the transmission of the data is stopped.

Abstract: A method of controlling a loop-back process between a local device and a remote device in an Ethernet passive optical network is disclosed. The method includes the steps of: (a) adding a predetermined field into a loop-back control OAM PDU in the loop-back process, the predetermined field having distinguishing messages for initiation o f a loop-back process and messages for termination of a loop-back process; and (b) the local device and the remote device performing a loop-back process using the loop-back control OAM PDU.

Abstract: Disclosed is a bandwidth allocation method for an optical line termination (OLT) in a Gigabit Ethernet passive optical network (GE-PON) having one OLT and a plurality of optical network units (ONUs) connected to the OLT. The method includes the steps of transmitting a registration request grant message for granting an opportunity for transmitting a registration request signal from the OLT to the ONUs; determining the number of ONUs that transmitted registration request messages in response to the registration request grant message; and segmenting a single time slot into a plurality of minislots, segmenting a partial bandwidth of each of the segmented minislots so as to accommodate the ONUs, and allocating the segmented bandwidths to the ONUs that transmitted the registration request messages as voice bands.

Abstract: A MAC (Medium Access Control) control block for controlling transmission of data between a plurality of MAC clients and a plurality of MACs in an Ethernet passive optical network (EPON) is provided. The MAC control block includes the plurality of MAC clients and the plurality of MACs associated with the MAC clients for forming a frame for data transmission; a plurality of optical multipoint (OMP) blocks connected between the MAC clients and the MACs for implementing a multipoint control protocol (MPCP); and a multipoint gating control block for controlling the OMP blocks so that when any one of the OMP blocks is transmitting the data, the other OMP blocks are prevented from transmitting data.

Abstract: A method for transmitting OAM (Operation, Administration and Maintenance) packet data by a control multiplexer of an OAM sublayer in an Ethernet passive optical network (EPON) accords priority to OAM packet data over MAC (Medium Access Control) client data awaiting transmission. The control multiplexer multiplexes the OAM packet data and the MAC client data according to the priority and transmits the multiplexed data to the MAC entity.

Abstract: A method of transmitting security data from a source point to a target point in a point-to-multipoint communication system is provided. The method includes the steps of forming an encryption tag field that includes information about an encryption tag type, which indicates whether transmission data is encryption-enabled or encryption-disabled; forming a packet data field which includes encrypted transmission data; forming a first integrity check field indicating the CRC check sum of the encrypted data; forming a length and type field indicating the sum of the lengths of the packet data field and the first integrity check field. Finally, a transmission frame is formed with these formed fields, a source address field indicating the address of the source point, and a destination address field indicating the address of the target point.

Abstract: A method for checking whether a transmission is a multicast transmission or not is disclosed, which includes in an Ethernet passive optical network including an OLT and multiple ONUs connected to the OLT, checking whether a transmission is a multicast transmission or not by generating a multicast LLID that represents multicast information. Subsequently from a multicast MAC address in a MAC layer in the multiple ONUs or the OLT, so that at least one ONU from among the multiple ONUs or the OLT receives the multicast transmission, the method comprising the steps of: (1) modifying the multicast MAC address and mapping the modified address to a LLID field in a RS layer below the MAC layer; and (2) generating mode information, which represents a multicast transmission, being adjacent to the LLID field and locating the mode information, wherein, the RS layer checks whether a transmission transmitted to the ONU or the OLT is a multicast transmission or not.

Abstract: In a DBA (Dynamic Bandwidth Allocation) method for an E-PON including an OLT and ONUs, DBACNs (DBA Control Nodes) corresponding to processes in a tree algorithm are arranged in multi-level stages with the ONUs being in the lowermost stage. DBACNs or ONUs in a specific stage are connected to a DBACN from its immediately higher stage in a tree structure. A process of allowing a DBACN to collect bandwidth request information from DBACNs or ONUs in its immediately lower stage is performed sequentially from the lowermost DBACNs to the uppermost DBACN. The uppermost DBACN allocates the smaller one of a total available allocation-bandwidth and a total requested bandwidth to DBACNs in its immediately lower stage in their priority order. DBACNs, other than the uppermost DBACN, each allocate a bandwidth allocated down from a DBACN in the immediately higher stage to DBACNs or ONUs in the immediately lower stage in their priority order.

Abstract: An OAM capability discovery method in Ethernet passive optical network is disclosed. An OLT assigns identifications according to a registration request of the plurality of ONUs connected to the OLT. In response, the OLT transmits an OAM capability information message of the OLT to a random ONU from among the registered plurality of ONUs, and the random ONU transmits an OAM capability information message of the random ONU to the OLT, then finally the OLT transmits an OAM capability discovery completion message to ONU.