�1���� Introduction
������� 1.1���� General
������� 1.2���� Definitions
����������������� 1.2.1���� Exchange test points, exchange input and
output and half-connections
����������������� 1.2.3���� Measurement conditions
����������������� 1.2.4�� ��Transmission loss
����������������� 1.2.6���� Digital parameters
�2����
Characteristics of interfaces
������� 2.1���� Two-wire analogue interfaces
����������������� 2.1.1���� Interface Z
����������������� 2.1.2���� Interface C2
������� 2.2���� Four-wire analogue interfaces
����������������� 2.2.1���� Interface C1
������� 2.3���� Digital interfaces
����������������� 2.3.1���� Interface A
����������������� 2.3.2���� Interface B
����������������� 2.3.3���� V-type interfaces
�3����
Voice-frequency parameters of a connection between two interfaces of the
same exchange
������� 3.1���� General
������� 3.2���� Transmission loss through the exchange
������� 3.3���� Group delay
����������������� 3.3.1���� Absolute group delay
����������������� 3.3.2���� Group delay distortion
������� 3.4���� Noise and total distortion
����������������� 3.4.1���� Weighted noise
����������������� 3.4.2���� Total distortion including quantizing
distortion
������� 3.5���� Crosstalk
������� 3.6���� Discrimination against out-of-band signals applied to the
input interface
������� 3.7���� Spurious out-of-band signals received at the output interface
������� 3.8���� Echo and stability
�4����
Exchange transfer function � jitter and wander
Annex A � Information on the formulae used in this Recommendation to calculate
weighted noise and signal-to-total distortion ratio
������� A.1���� General
������� A.2���� Weighted noise
����������������� A.2.1���� Weighted noise for an input connection
originating from a Z-interface
���������������� �A.2.2����
Weighted noise for an output connection terminating in a Z-interface
����������������� A.2.3���� Weighted noise for a whole connection
originating from and terminating in a Z‑interface
����������������� A.2.4���� Weighted noise for an input connection
originating from a 2-wire or 4-wire C‑interface with or without
signalling on the speech wires
����������������� A.2.5���� Weighted noise for an output connection
terminating at a 2-wire C-interface with Lo � or a 4‑wire C-interface both with or without signalling on
the speech wires
����������������� A.2.6���� Weighted noise for an output connection
terminating at a 2-wire C-interface with Lo <-5 dBr and with or without signalling on
the speech wires
����������������� A.2.7���� Weighted noise for a whole connection
originating from and terminating in 2-wire or 4‑wire C‑interfaces
with or without signalling on the speech wires���� 24
������� A.3���� Total distortion including quantizing distortion
����������������� A.3.1���� Total distortion including quantizing
distortion for an input connection originating from a Z-interface
����������������� A.3.2���� Total distortion including quantizing
distortion for an output connection terminating in a Z‑interface
����������������� A.3.3���� Total distortion including quantizing
distortion for a whole connection originating from and terminating in a
Z-interface
����������������� A.3.4���� Total distortion including quantizing
distortion for an input connection originating from a 2-wire or a 4‑wire C-interface
����������������� A.3.5���� Total distortion including quantizing
distortion for an output connection terminating in a 2‑wire or a 4‑wire
C-interface
����������������� A.3.6���� Total distortion including quantizing
distortion for a whole connection originating from and terminating in 2-wire or
4-wire C-interfaces
Annex B � Explanation of power, dBm, dBr, dbm0 and mW units of speech band
signals in ITU
������� B.1���� Introduction
������� B.2���� The case of resistive nominal impedances, constant with
frequency
������� B.3���� The case of complex nominal impedances, varying with frequency