Digital Signal 3
Digital Signal 3 (DS-3) is one of the signaling levels in the North American Digital Signaling Hierarchy. It is a 44.736 Mbps transmission facility that can be channelized into 28 DS-1 channels, or left unchannelized to provide a single 44.184 Mbps transmission channel. Because the DS-3 service was initially delivered over T-3 facilities, the terms T-3 and DS-3 have come to be used interchangeably. In general, however, the DS-n language refers to the service provided, and the T-n language refers to the facility on which it is provided.