Digital data network(DDN) is contrived to transmit data signals with digital channels( optical cable or digital microwave) and digital cross connect(DXC) equipment.是什么意思_Digital data network(DDN) is contrived to transmit data signals with digital channels( optical cable or digital microwave) and digital cross connect(DXC) equipment.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句