A.80G B.70G C.60G D.50G
A.120G B.140G C.160G D.180G
A.充分利用光纖帶寬 B.節(jié)約光纖,降低成本 C.實(shí)現(xiàn)多速率、多業(yè)務(wù)混合傳輸 D.采用同步復(fù)用方式和靈活的復(fù)用映射