摘要:
An apparatus and method for managing traffic using a VID in EPON are provided. The apparatus includes a MAC lookup table, a service classification policy table, a service control policy table, a MAC lookup unit, a first and second classification module, a VID learning unit and a first and second service control module. The apparatus classifies all packets of up/downlink transmission flow using a VID into a VID unit, through the first and second classification modules and manages traffic thereof according to the parameters thereof through the first and second service control modules. Accordingly, a large amount of traffic for numerous subscribers and services thereof, which was cannot be processed by the limitation on embodying a typical switch or router, can be processed according to the present invention.
摘要:
Disclosed herein is an optical transmitter having an analog/digital mixed-mode temperature compensation function. The optical transmitter, when detecting the optical output power of a laser diode, which outputs logic levels “1” and “0” as optical signals, through a monitoring photodiode, and controlling the bias current of a laser drive circuit to maintain the logic levels “1” and “0” at constant values, includes programs for controlling the bias current and modulation current of the laser drive circuit based on an variation in temperature, and is configured such that a temperature compensation circuit includes a digital control unit for controlling the bias current and modulation current of the laser drive circuit using the programs, so that temperature compensation operation can be adjusted only by the modification of the programs of the distal control unit.
摘要:
The invention provides a method and apparatus for allocating a dynamic band width of an EPON and an EPON master apparatus using the same. The bandwidth allocation is cycle based where every predetermined cycle, static gates are generated for all ONUs and dynamic gates are generated according to the reports using the remaining grant resource. The method for allocating an upstream bandwidth to transmit data from the ONUs to an OLT is as follows. A total allocatable grant length is calculated for the given cycle. A requested amount of grant length needed to transmit upstream data in each ONU is set based on report values collected from the report frames from all ONUs in the EPON. Then, distribution is made sequentially and repeatedly in a cycle by taking a basic unit from the total grant length and adding it to the grant length of the ONUs until the total allocatable grant length becomes 0 or the grant length allocated to all ONUs satisfy the requested amount of the grant length set in all ONUs.
摘要:
A high-speed Galois Counter Mode-Advanced Encryption Standard (GCM-AES) block cipher apparatus and method is provided. The apparatus can operate at a low clock frequency of 125 MHz and provide a 2 Gbps link encryption function in an Optical Line Termination (OLT) and an Optical Network Unit (ONU) of an Ethernet Passive Optical Network (EPON). 11-round block cipher of 128-bit input data is implemented using an 8-round Counter-AES (CTR-AES) block cipher module and a 3-round CTR-AES block cipher module, so that it is possible to provide a 1 Gbps link security function for an input frequency of 62.5 MHz and a 2 Gbps link security function for an input frequency of 125 MHz.
摘要:
An authentication method for link protection between an OLT and an ONU newly connected thereto in an EPON, which is implemented in a data link layer to which cryptography is applied. First, an authentication key is distributed to both the OLT and an ONU. The OLT (or ONU) generates first and second random values, generates an authentication request frame containing the random values, and transmits it to the ONU (or OLT). The ONU generates a first hash value according to a hash function using the random values contained in the request frame, and transmits an authentication response frame containing the first hash value to the OLT. The OLT compares the first hash value with a second hash value calculated by it according to the has function using the two random values and an authentication key distributed to it, and transmits an authentication result frame to the ONU.
摘要:
An apparatus for transmitting a FEC frame is provided. The apparatus includes: a selector determining whether to perform FEC encoding on data to be transmitted; a Reed-Solomon encoding assembler receiving the data on which FEC encoding is to be performed as determined by the selector, and dividing the data into k-byte message blocks (k is a positive integer) for output; a Reed-Solomon encoder receiving the message blocks and performing Reed-Solomon encoding on the message blocks; and an output controller receiving an input parity generated by the Reed-Solomon encoding, and outputting the message block and the parity sequentially or outputting the data on which FEC encoding is not to be performed as determined by the selector. In order to correct an error caused by a transmission medium using FEC in a Reed-Solomon code type, FEC encoding/decoding of a frame is performed. A total transmission delay time is not influenced when FEC is bypassed, a delay caused by a shortened codeword is minimized, and a FEC encoding/decoding delays for frames having different lengths are equalized.
摘要:
A method of controlling a Forward Error Correction (FEC) operation including: configuring a FEC frame to be transmitted between an OLT and an ONU comprising a FEC frame identifier indicating whether FEC should be performed, data, a first flag indicating that FEC should be performed, and a second flag indicating that the FEC frame is to be FEC encoded; initializing the OLT by disabling a FEC function; determining whether the ONU requires FEC to be performed based on a FEC frame identifier received from the ONU; IPG stretching the FEC frame when the ONU requires to FEC to be performed; and transmitting the FEC frame to the ONU after FEC encoding based on the second flag of an input frame to a PCS sublayer from an upper layer. The method controls an effective operation of a FEC of an ONU and an OLT without changing a Round Trip Time (RTT) according to optical link quality in an EPON. Accordingly, FEC is used only if necessary, thereby simplifying the managing of a link, and preventing an excessive 35% reduction of throughput caused by use of unnecessary FEC.
摘要:
Disclosed herein is a backlight unit, capable of easily forming a curved or three-dimensional shape. The backlight unit according to the present invention comprises a light guide panel which includes a light guide plate having on one surface or both surfaces thereof a plurality of notches, an uneven dot pattern, a printed dot pattern or a sanded surface, or a light diffusion plate; a luminous means which includes a lamp mounted on a PCB to emit light to the light guide panel; a groove formed along an edge of the light guide panel so that the luminous means is installed in the light guide panel; and a thin heat radiating plate fixed on a back surface of the PCB along the groove.
摘要:
A system and method is disclosed for determining performance bonds related to fixed payoff products, i.e. contracts which payoff a fixed amount based on the outcome of an underlying event regardless of the particular value of the underlying event. The worst outcome of the overall portfolio, which may contain more than one instrument, is calculated. This permits the portfolio to have both long and short positions on the same underlying event and offsets, e.g. long (bought but not closed out) and short (sold but not closed out) positions, among instruments in the portfolio are factored in. A universe of outcomes is constructed including single events with single outcomes, and the probability thereof, an single events with multiple outcomes, each with a probability thereof. This universe is implemented in a matrix probabilities on different outcomes, also referred to as “strikes.” Each strike/outcome then has an associated price and probability, typically factored together as single value reflective of both. Events with low probability will have low values, resulting in a lower margin requirement, as will be explained below. The margin requirement/performance bond is then set equal to the amount of the maximum loss that the portfolio can sustain for any possible outcome of the underlying event, adjusted for the probability of the outcome.
摘要:
A system and method for factoring in a trader's trading activity into the margin requirements is disclosed. In the securities arena, day traders are assessed different margins than non-day-traders, however, the specific profile of the trader is analyzed (that is, the same rule applies to all day traders).