A DS-3, or Digital Signal 3, is a high-capacity digital transmission line used in telecommunications. It can carry data at a rate of 44.736 megabits per second (Mbps) and is commonly used to transmit voice and data over long distances. The DS-3 is part of the T-carrier system, which was developed by AT&T to provide reliable communication services. In practical terms, a DS-3 line can support multiple T1 lines, allowing for the simultaneous transmission of numerous phone calls or data streams. It is often utilized by businesses and service providers to ensure efficient and high-speed connectivity, making it a vital component of modern communication infrastructure.