同步数位阶层 tóng bù shù wèi jiē céng

DEFINITIONS

  1. synchronous digital hierarchy
  2. SDH

CHARACTERS

同 tóng same, similar; together with
步 bù step, pace; walk, stroll
数 shù number; several, count; fate
位 wèi throne; position, post; rank, status; seat
阶 jiē stairs, steps; rank, degree
层 céng story, layer, floor, stratum