scope:

This European Telecommunication Standard (ETS) specifies the electrical characteristics, the functional characteristics and the corresponding conformance tests for Terminal Equipment (TE) for connection to the network termination points of a Public Switched Telephone Network (PSTN) interface providing a Protocol over the local loop for display and related services based on the protocols defined in ETS 300 659-1 [1]. This ETS applies to the asynchronous voice-band Frequency Shift Keying (FSK) based subscriber line protocols.