| 摘要 |
PURPOSE: A circuit board for mixing and receiving frame relay/ATM subscribers in ATM exchange is provided to possess a frame relay and an ATM subscriber boards to one circuit board, thereby using the boards on occasion demands and enhancing the economy. CONSTITUTION: A line interface unit(21) converts an analog signal applied from the line of ATM subscriber or frame relay subscriber into a digital signal and then applies the digital signal to a framer(22), and also converts a digital signal applied from the framer(22) into an analog signal and then applies the analog signal to a line. The framer(22) removes the frame among the signal applied from the line interface unit(21), extracts TDM signal and then transmits the signal to an HDLC(High-level Data Link Control) processor(23) or an ATM physical layer processing unit(26), and also processes the TDM signal applied from the HDLC processor(23) or the ATM physical layer processing unit(26) as a frame and then outputs the processed signal to the line interface unit(21). The HDLC processor(23) converts the TDM signal into a packet and then outputs the packet to a CPU(24) through a local bus and also, converts the packet applied from the CPU(24) through the local bus into the TDM signal and then outputs the TDM signal to the framer(22). The CPU(24) processes the packet and then outputs the packet to an SAR(Segmentation and Reassembly) processing unit(25), and also processes the packet applied from the SAR processing unit(25) to the HDLC processing unit(23). The SAR processing unit(25) separates the packet, interfaces with UTOPIA(Universal Test and Operations Physical Layer Interface for ATM) and then outputs the packet to a backboard(27) of ATM exchange, and also reassemblies the separated packet applied from the backboard(27) by the interface with UTOPIA and then outputs the packet to the CPU(24). An ATM physical layer processing layer(26) extracts an ATM cell from the TDM signal applied from the framer(21), interface with UTOPIA and then outputs the ATM cell to the backboard(27) of ATM exchange, and also converts the ATM cell applied from the backboard(27) by the interface with UTOPIA to TDM signal and then outputs the signal to the framer(22). |
