DS0s

DS0s, or Digital Signal 0, are the most basic digital signaling channels used in traditional telecommunications. A DS0 carries a single voice or data channel at a rate of 64 kilobits per second (kbps). In pulse-code modulation (PCM) systems, this 64 kbps results from sampling a voice signal at 8 kHz with 8-bit samples, i.e., one 8-bit sample every 125 microseconds.

DS0s are the building blocks of larger digital hierarchies. In North American T-carrier systems, 24 DS0s are multiplexed to form a DS1 (commonly called a T1) with a total rate of 1.544 Mbps, along with overhead bits for framing and signaling. In the European E-carrier system, 31 DS0 channels are carried within an E1 line at 2.048 Mbps, with one timeslot typically used for framing. These arrangements illustrate how many separate 64 kbps channels can be combined to support higher-throughput trunks.

Although largely associated with legacy and fixed-line telephony, DS0 concepts remain relevant for understanding digital transmission, PDH/SDH frameworks, and PCM-based multiplexing. They provide a simple, uniform 64 kbps channel that simplifies the organization and routing of individual voice paths across digital networks. In modern networks, DS0s have been largely superseded by more advanced transport methods, but the fundamental idea of a single 64 kbps data channel persists in many contexts.