Page 652 - 5G Basics - Core Network Aspects

2 Transport aspects

Editorial note: This is a complete-text publication. Modifications introduced by this amendment are shown
in revision marks relative to Recommendation ITU-T G.9700 (2014) plus its Amd. 1 (2016).

1 Scope
This Recommendation complements the physical layer (PHY) specification in [ITU-T G.9701].
It specifies:

− power spectral density (PSD) limit mask requirements;
− a set of tools to support reduction of the transmit PSD mask;
− profile control parameters that determine spectral content, including the allowable maximum
aggregate transmit power into a specified termination impedance; and
− a methodology for transmit PSD verification.
This ensures that the technology can address:

− regional requirements;
− operator deployment requirements, for example, compatibility with other digital subscriber line
(DSL) technologies;

− applicable electromagnetic compatibility (EMC) regulations or standards; and
− local EMC issues.

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.993.2] Recommendation ITU-T G.993.2 (2011), Very high speed digital subscriber line
transceivers 2 (VDSL2).
[ITU-T G.9701] Recommendation ITU-T G.9701 (2014), Fast access to subscriber terminals (G.fast) –
Physical layer specification.

3 Definitions
This Recommendation defines the following terms:
3.1 ceiling(x): The smallest integer which is not less than x.

3.2 floor(x): The largest integer which is not greater than x.
3.3 fSC: A parameter representing the frequency of subcarrier spacing.

3.4 subcarrier: 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.

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