[计] frequency division multiplex telegraph system

pín fēn duō lù fù yòng diàn bào xì tǒng ㄆㄧㄣˊ ㄈㄣ ㄉㄨㄛ ㄌㄨˋ ㄈㄨˋ ㄩㄥˋ ㄉㄧㄢˋ ㄅㄠˋ ㄒㄧˋ ㄊㄨㄥˇ