| 摘要 |
PURPOSE: A cell transmission device is provided to perform a CRC(Cyclic Redundancy Check) process for payload of an ATM cell by using an unused part of an ATM cell format of a UTOPIA level2 interface, thereby improving transmission reliability of the ATM cell. CONSTITUTION: An E1/T1 framer(90) converts information of a line level of an E1/T1 frame into PCM data, loads the PCM data into each channel by being synchronized with a frame synchronous signal, converts the PCM data into frame data, and transmits the frame data to an AAL2 processor(80), then converts frame data applied from the AAL2 processor(80) into the information of the line level of the E1/T1 frame. The AAL2 processor(80) makes an AAL2 packet with the PCM data, assembles the AAL2 packet to an ATM cell, and transmits the ATM cell to a CRC inserter/checker(70). The CRC inserter/checker(70) inserts a CRC-6 code to transmit the code to an ATM exchange interface(60), and checks whether payload has an error, and if so, transmits error information to an upper processor. The ATM exchange interface(60) transmits the ATM cell to an ATM exchange, and transmits a cell of the ATM exchange to the CRC inserter/checker(70).
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