| 摘要 |
<p>PURPOSE:To set freely the structure of one multi-frame in the looped data transmission system. CONSTITUTION:A one-multi-frame consists of 20 STM-1 frames F(1)-F(20). rows (1-9) and time slots (1-9) of the STM-1 frame are an SOH (section overhead) and a virtual C4 is set to the rows (1-9) and time slots (11-270) of the STM-1 frame. A prescribed time slot in the virtual C4 is used for a multi-frame synchronization pattern and time slots of an optional number are used for a house keeping channel and the remaining time slots are used for a service channel.</p> |
