In telephone communications, a technology that increases the number of channels in the local loop by converting analog signals to digital and multiplexing them back to the end office. Digital loop carriers (DLCs) have increased the capacity of the installed cable plant by enabling several hundred conversations to ride over two twisted wire pairs. A carrier serving area (CSA) is the geographic boundary served by a DLC. Digital loop carrier equipment is either above ground or in small weatherproof, underground rooms typically within a mile of the final drop to the customer. The host terminal is the equipment at the end office, and the remote terminal is situated in the outside plant (from end office to customer). The closer the DLC is to the customer, the shorter the analog line and the greater the performance. Analog lines, which used to be three miles long, are now less than a mile in many cases. See central office and pair gain.