Abstract: A method of controlling a loop-back process between a local device and a remote device in an Ethernet passive optical network simplifies the initiation and the termination processes for a loop-back process by avoiding the use of Operation, Administration and Maintenance—Packet Data Unit (OAM PDU) information along with a loop-back control OAM PDU. 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 of 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 upstream data transmission method in a gigabit Ethernet-passive optical network (GE-PON) system. In the GE-PON system including an optical line termination having a scheduler and optical network units connected to the optical line termination, the optical line termination receives bandwidth allocation request signals from the optical network units at a start of a first cycle, allocates transmission bandwidths to the respective optical network units in accordance with the bandwidth allocation request signals, and transmits the allocated transmission bandwidths to the respective optical network units before a second cycle that follows the first cycle.

Abstract: An apparatus and method for enabling cost-effective duplex communication by diplexing one of down stream signals for frequency up-conversion in a hybrid fiber-radio system includes diplexing an unmodulated mode signal among beating signals between a master laser and an injection-locked slave laser and using the diplexed signal for down-conversion in upstream transmission, thereby eliminating the need for expensive high-frequency local oscillators for frequency conversion. Higher radio frequency signals can be generated using beating between basic modes and satellite modes such as FWM conjugates of the master laser and slave laser. Cost-effective systems, stabilization of a light source and improved transmission performance may be achieved by using a diplexer instead of an expensive high-frequency local oscillator.

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.

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 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: An apparatus and method for enabling cost-effective duplex communication by diplexing one of down stream signals for frequency up-conversion in a hybrid fiber-radio system includes diplexing an unmodulated mode signal among beating signals between a master laser and an injection-locked slave laser and using the diplexed signal for down-conversion in upstream transmission, thereby eliminating the need for expensive high-frequency local oscillators for frequency conversion. Higher radio frequency signals can be generated using beating between basic modes and satellite modes such as FWM conjugates of the master laser and slave laser. Cost-effective systems, stabilization of a light source and improved transmission performance may be achieved by using a diplexer instead of an expensive high-frequency local oscillator.

Abstract: A key agreement method for secure communication in a multiple access system is provided.

Abstract: Disclosed is a point-to-point emulation method for operating an Ethernet passive optical network having an optical line terminal (OLT) and a plurality of optical network units (ONUs) each connected to the OLT. A tag Ethernet frame transmitted between the OLT and the ONUs includes a destination address (DA) field representing a destination address, a source address (SA) field representing a source address, and an LLID field in which a unique LLID assigned to an object of the ONU side is recorded. The LLIDs are assigned to ports of a bridge or an L2 (Layer 2) switch of the OLT side on a one-to-one basis. The OLT, upon receiving a tag Ethernet frame, outputs an LLID field-deleted Ethernet frame to the bridge or L2 switch port to which an LLID in the received frame is assigned. The bridge or the L2 switch transmits the Ethernet frame to a port to which a previously learned destination address is assigned.

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: 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: 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 tunable optical oscillator that generates optical signals at a band of micro- to millimeter-wave is provided. The tunable optical oscillator includes an electrical signal generator for generating an electrical signal at the predetermined band; a master laser that is driven by the electrical signal, and generates an optical signal having a first frequency; and a slave laser that is driven by an electrical signal, injected into the optical signal generated by the master laser, generates an optical signal having a second frequency, and mixes the received optical signal with the optical signal having a second frequency to be output. The tunable optical oscillator is capable of generating signals over a broadband including micro- to millimeter-wave and beyond, say, from tens of MHz to several THz. The generated signals by the optical oscillator have also frequency tunability over the range of tens of GHz with coarse tuning methods to tens of MHz with fine tuning methods.

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.