scope:

The present document specifies requirements for transceivers providing bi-directional symmetrical high bit rate transmission on a metallic wire pair using the echo cancellation method. The technology is referred to as Symmetric single pair high bit rate Digital Subscriber Line (SDSL), and is applicable to metallic access transmission systems designed to provide digital access over existing, unshielded wire pairs. It was originally specified for a single pair only and referred to as Symmetric single pair high bit rate Digital Subscriber Line (SDSL), but is enhanced in this new version for transmission on M pairs in parallel.

The present document and the requirements for their implementation define the functional requirements for SDSL.

The requirements imply interoperability of SDSL systems. Such interoperability will be achieved when SDSL transceivers provided by different manufacturers are used in one SDSL link.

The definition of physical interfaces is outside the scope of the present document. The SDSL transmission system consists of an application independent core and an application specific block. The core is considered a transport bit-pump, which transports information from one end of the metallic link to the other. The data is mapped into a frame, which is considered to be the interface between the application specific and independent parts of the SDSL system. This frame is only used internally and is not accessible.