摘要:
An asynchronous transfer mode (ATM) host adapting apparatus comprising: a storage block for storing packet information, received cells, and parameters; an ATM network interface handling block for performing direct memory access of ATM cells and parameter stored therein, segmenting transmit packet information, reassembling received cells, transmitting and receiving the ATM cells to physical media cell received, and arbitrating in the direct memory access; and a secondary interface block for connecting the storage block to the ATM network interface handling block.
摘要:
A finite impulse response (FIR) filter for wave-shaping digital quadrature amplitude modulation (QAM) symbols is disclosed, in which multipliers are replaced with multiplexers, the replaced multiplexers are utilized to receive the symbols directly from a symbol encoder without zero (0) interpolations, and the critical path is reduced by shifting the position of a delay device. The filter includes a first FIR means for delaying the externally inputted symbol data, and for utilizing the delayed symbol data as selection signals to sum up the selected multiplication product (selected from among products obtained by multiplying the symbol values by a pre-set filter tab coefficient) and the selected value selected by a first multiplexing means. A second FIR means delays again the delayed symbol data of the first FIR means, and utilizes the delayed symbol data as selection signals to sum up the selected multiplication product and the output value of the first FIR means.
摘要:
A fully-interconnected ATM switching apparatus comprising a plurality of line interface circuits, each of the line interface circuits including an input port driver for extracting an SDH transmission frame containing cell data with a fixed length and a connection identifier from an input signal, appending a routing tag to the extracted SDH transmission frame and outputting the resultant SDH transmission frame through an input dedicated bus and an output port driver for receiving a cell stream from an output dedicated bus, removing the routing tag from the received cell stream, translating a channel identifier in the connection identifier and transferring the resultant SDH transmission frame to an adjacent node, a system clock distributor for generating a clock signal, an initialization controller for controlling system initialization and restart operations, a switch maintenance controller for performing a switch maintenance control operation in response to a network managing cell, a switch call processing controller for performing a call processing operation, a switch module controller for controlling a switching operation, and a plurality of switch output multiplexers for switching cells from the input port drivers to the output port drivers under the control of the switch module controller.
摘要:
The present invention relates to a fixed length packet switching apparatus using multiplexers and demultiplexers in which the apparatus has an output buffer-type construction, protects itself from a temporary overflow occurrence of an output terminal and has the construction of the mutual flow control to enhance its entire performance. The present invention can protect the entire operations as well as enhance the entire performance of the switching apparatus by preventing an obstacle of the switching apparatus due to an overflow temporarily generated from an output terminal, process without a loss of excessive cells a traffic phenomenon of one output port in the switching apparatus, reduce the necessary buffer according to the effect of the rate gain and process smoothly input traffic of the internal buffer having a burst characteristic. Further more, the present invention has a duplicate function of cells able to provide a broadcast-type service distributed to subscribers at one time so that the subscribers can receive a distributed service to thereby increase the effectiveness of the channel.
摘要:
A direct memory read and cell transmission apparatus for an ATM cell segmentation system having a host CPU is disclosed. The segmentation circuit of the apparatus transfers the address and size for the start of the DMA by the byte unit. When a predetermined information is provided, and a DMA read is requested, the data is transferred through the bus of the word unit such as the PCI interface, and then necessary bytes are obtained for thereby forming a 32 bit word stream, so that the ATM cell of a 32 bit×12 word form and transfers to the lower circuit. Therefore, when the segmentation circuit processes the buffer, all data are computed by the byte unit, and in an application program, the data are not obtained for transmitting the data to the ATM cell, so that it is possible to enhance the processing capability.
摘要:
The present invention relates to an Asynchronous Transfer Mode (ATM) multi-channel switch with a structure of grouping/trap/routing that, by designating a port as a group, could accept not only the services having higher speed than the speed of input ports, but also the services having super-rate speed by comprising: an input processing unit for executing reading control of externally inputted cells and adjusting synchronization between an externally inputted cell and a cell returned by blocking and feedback; a channel grouping unit for grouping cells outputted from the input processing unit, according to switching control data; a trapping unit for deciding whether cells grouped in the channel grouping means require switching beyond the capacity of the pertinent channel and, if these cells require switching beyond the capacity of the channel, sending them to the input processing unit by feedback; and a routing unit for routing cells outputted from the trapping unit.