Page 677 - 5G Basics - Core Network Aspects

Transport aspects 2

2 References

The following ITU-T Recommendations and other references contain provisions which, through reference in
this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated
were valid. All Recommendations and other references are subject to revision; users of this
Recommendation are therefore encouraged to investigate the possibility of applying the most recent
edition of the Recommendations and other references listed below. A list of the currently valid ITU-T
Recommendations is regularly published. The reference to a document within this Recommendation does
not give it, as a stand-alone document, the status of a Recommendation.
[ITU-T G.117] Recommendation ITU-T G.117 (2007), Transmission impairments due to speech
Processing.
[ITU-T G.994.1] Recommendation ITU-T G.994.1 (2012), Handshake procedures for digital subscriber
line transceivers.
[ITU-T G.997.2] Recommendation ITU-T 997.2 (2015), Physical layer management for ITU-T G.9701
transceivers.

[ITU-T G.9700] Recommendation ITU-T G.9700 (2014), Fast access to subscriber terminals (G.fast) –
Power spectral density specification.

[ITU-T O.9] Recommendation ITU-T O.9 (1999), Measuring arrangements to assess the degree of
unbalance about earth.

[ITU-T T.35] Recommendation ITU-T T.35 (2000), Procedure for the allocation of ITU-T defined
codes for non-standard facilities.

[ISO 8601] ISO 8601:2000, Data elements and interchange formats – Information interchange –
Representation of dates and times.

3 Definitions

3.1 Terms defined elsewhere
This Recommendation uses the following terms defined elsewhere:

3.1.1 ceiling(x) [ITU-T G.9700]: The smallest integer which is not less than x.
3.1.2 floor(x) [ITU-T G.9700]: The largest integer which is not greater than x.
3.1.3 fSC [ITU-T G.9700]: A parameter representing the frequency of subcarrier spacing.

3.1.4 subcarrier [ITU-T G.9700]: A fundamental element of a discrete multitone (DMT) modulator. The
modulator partitions the channel bandwidth into a set of parallel subchannels. The centre frequency of
each subchannel is a subcarrier onto which bits may be modulated for transmission over a channel.

3.2 Terms defined in this Recommendation

This Recommendation defines the following terms:
3.2.1 active line: A line where both of the connected transceivers (FTU-O and FTU-R) are in showtime.

3.2.2 aggregate net data rate (ANDR): The sum of the net data rate (NDR) in downstream and
upstream.

3.2.3 bearer channel: A transparent data channel between the γ reference points of peer transceivers
(i.e., from the γO at the FTU-O to the γR at the FTU-R, or vice versa).
3.2.4 BLACKOUT set: A subset of the SUPPORTEDCARRIERS set determined by the receiver during the
initialization to be allocated no power by the transmitter.

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