A.中频调制 B.中频解调 C.中频预失真放大 D.中频放大
单项选择题AT接入鉴权的时候,包括 (1)ChApchAllenge-response, (2)A12Acessrequest, (3)A12AcessAccept, (4)chApAuthentificAtionsuccess,信令流程正确的顺序是:()
A.1-2-3-4 B.1-3-2-4 C.2-1-3-4 D.2-3-1-4