| 摘要 |
A clock supply apparatus provided in each slave office, wherein a single master clock is received at a clock receiver unit; 0-system and 1-system system clocks are paired and are distributed to the transmission units at terminal ends via a plurality of duplexed clock supply routes; and multistage clock selection units are hierarchically inserted into the duplexed clock supply routes. The system-selection unit for controlling the selection of the 0-system or 1-system at each clock selection unit is given a 0-system and 1-system duplexed structure and is constituted by a system switching command unit for instructing this system-selection.
|
