common carrier

名词 common carrier:

1. a person or firm in the business of transporting people or goods or messages
   同义词：carrier

1. In communications, the connection, by a common carrier, of the output portion of a circuit back to the input portion of a circuit.
   在通信技术中，通过公共载体将电路的输出部分返回到电路的输入部分的一种连接。