Other expression · CEFR C2
common battery signalling
other_expression
一种电话信令方式,信令所需电力由交换机处的中央电池提供。
- 1.
A telephony signalling method in which the electrical power for the signal is supplied from a central battery at the exchange.
一种电话信令方式,信令所需电力由交换机处的中央电池提供。
In use
Common battery signalling was widely used in early automatic telephone exchanges.
Dictionary facts from AI_SUPPLEMENT.