| 摘要 |
<p>PURPOSE:To identify the storing of an ATM(Asynchronous Transfer Mode) signal in a digital hierarchy (SDH) transmitter. CONSTITUTION:For an ATM cell 4 mapped to a virtual container (VC)-4, the position in a pay load 15 is dislocated backwards by 5 bytes per one line and when the VC-4 constituted of 9 lines is a reference, the position is dislocated by 45 bytes. Then, the value of an H4 byte 3 of a pass overhead (POH) 2 is monitored, 45 is added to the value of the H4 byte of a certain VC-4, and when the result exceeds 52, the value for subtracting 53 from it, and when the result does not exceed 52, the value is compared with the value of the H4 byte of the next VC-4 as it is and at the time of the coincidence, that is, it is decided as the storing of the ATM signal.</p> |
