Digital loop carrier

A variety of schemes were implemented before DLC technology to offset the impedance long loops offered to signalling and volume levels.

They included the following: DLC eliminates the need for these remedies by extending closer to the customer the line card which digitises the voice signal for use by the PSTN.

Once the voice signal is digitised, it is easily manipulated and is no longer subject to the vagaries of the analog loop caused by distance, impedance, attenuation and noise.

DLC remote terminals are typically stored in Serving Area Interfaces–metal cabinets alongside or near roadways that overlie communications rights-of-ways.

FITL accomplishes the same two primary functions DLC was intended for: pair gain and the elimination of electrical constraints due to long metallic loops.