Development of unattended private automatic branch exchanges . two - line monophones introduced 開發(fā)無人自動小交換機。二線制收發(fā)話機問世。
Generic specification for stored program control digital private automatic branch telephone exchange system 程控數(shù)字用戶自動電話交換機通用技術(shù)條件
General specification for stored program control analogue private automatic branch telephone exchange system 程控模擬用戶自動電話交換機通用技術(shù)條件
Rapid expansion in the use of private automatic branch exchanges . development of remote alarm equipment for unattended exchanges 用戶自動交換機迅速普及。開發(fā)無人交換機遠(yuǎn)端報警設(shè)備。
Public automatic branching exchange ( pabx ) a telephone system installed in atcx for efficient communications between operational positions in the atcx and external parties through the public service telephone network . microwave link system ( mls ) 這套在航空交通管制大樓內(nèi)安裝的電話系統(tǒng),可為管制崗位提供更有效率的內(nèi)部通訊,同時,透過公共電話網(wǎng)絡(luò)服務(wù),也可對外作快捷的通話。