A.{1–[∑光纖故障芯數(shù)(芯)×故障時(shí)間(mim)]/[實(shí)際光纖芯數(shù)(芯)×全月日歷時(shí)間(mim)]}×100%
B.{1–[∑光纖故障芯數(shù)(芯)×故障時(shí)間(mim)]/[實(shí)際光纖芯數(shù)(芯)×全月日歷時(shí)間(mim)]}
C.{1–[∑光纖故障芯數(shù)(芯)×故障時(shí)間(mim)]/[實(shí)用光纖芯數(shù)(芯)×全月日歷時(shí)間(mim)]}
D.{1–[∑光纖故障芯數(shù)(芯)×故障時(shí)間(mim)]/[實(shí)用光纖芯數(shù)(芯)×全月日歷時(shí)間(mim)]}×100%