scope:

This standard specifies those technical characteristics (logical and electroacoustic) that are necessary to provide end-to-end compatibility of terminal equipment of the 3,1 kHz telephony teleservice which is intended for connection to the ISDN basic rate interface at the coincident S/T or S reference point.

The requirements of this standard are in addition to those of standards for connection to the ISDN basic rate interface. The requirements of this standard describe the logical characteristics of the user-network signalling over the D-channel relevant to this service.

The requirements of this standard provide real time two-way speech of a quality consistent with the CCITT P. series Recommendations.

The requirements of this standard define only those characteristics relevant to normal handset telephony.

This standard is not applicable to:

a) hands-free or loudspeaking telephony;

b) cordless telephony;

c) telephony for disabled people (e.g. with amplification of received speech as an aid for the hard of hearing);

d) telephony in hostile environments.

However, other standards that apply to such functions will ensure compatibility with handset telephony.

NOTE 1: The characteristics of the ISDN user-network interface are specified in final draft prETS 300 012 [1], ETS 300 102-1 [3] and ETS 300 104 [4].

NOTE 2: Type approval requirements for terminals accessing this teleservice can be found in ETS 300 085 [2], 300 105 [4] and draft prETS 300 153 [6].