短語詞組短語signaling g line circuit 信號線電路signaling g line 信號線signaling line circuit 信號線電路Line Signaling 線路信令LSE Line Signaling Equipment 線路信令設備analog line signaling 模擬用戶信令line signaling unit 線路信令單元Subscriber line signaling 用戶線信令line signaling system 線路信令系統(tǒng) 返回 signal line