1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T G.9700 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 2 (06/2017) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Access networks Metallic access networks Fast access to subscriber terminal
2、s (G.fast) Power spectral density specification Amendment 2 Recommendation ITU-T G.9700 (2014) Amendment 2 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANA
3、LOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COO
4、RDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND
5、 USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 Metallic access networks G.9700G.9799 Optical line systems for local and access networks G.9800G
6、.9899 In premises networks G.9900G.9999 For further details, please refer to the list of ITU-T Recommendations. . Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) i Recommendation ITU-T G.9700 Fast access to subscriber terminals (G.fast) Power spectral density specification Amendment 2 Summary Recommendatio
7、n ITU-T G.9700 specifies power spectral density (PSD) mask requirements for fast access to subscriber terminals (G.fast), 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
8、 into a specified termination impedance, and a methodology for transmit PSD verification. It complements the physical layer (PHY) specification in Recommendation ITU-T G.9701. Amendment 1 provided support for a new 106 MHz profile with +8 dBm maximum aggregate transmit power. Amendment 2 aligns the
9、text of clause 6.5 on notching of specific frequency bands with ITU-T G.9701 (2014) and its latest amendments, completes the specification of 212 MHz profiles, adds Annex X Adaptation to the coax medium in support of Annex X Operation without multi-line coordination intended for a crosstalk free env
10、ironment that has been specified in amendment 3 to ITU-T G.9701, and updates the table of International amateur radio frequencies in Appendix I. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.9700 2014-04-04 15 11.1002/1000/12010 1.1 ITU-T G.9700 (2014) Amd. 1 2016-09-30
11、15 11.1002/1000/12842 1.2 ITU-T G.9700 (2014) Amd. 2 2017-06-30 15 11.1002/1000/13170 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii
12、Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent or
13、gan of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the
14、 topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are
15、 prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendati
16、on may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used
17、 to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectu
18、al Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice
19、 of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 201
20、7 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 1 4 Abbreviations and acronyms 2 5 Conventions 2
21、6 Transmit PSD mask 2 6.1 Overview 2 6.2 Limit PSD mask (LPM) 3 6.3 Subcarrier masking . 3 6.4 Power spectral density shaping 4 6.5 Notching of specific frequency bands 4 6.6 Low frequency edge stop-band masking 6 7 Specification of spectral content . 7 7.1 Profile control parameters 7 7.2 PSD mask
22、specifications 7 7.3 Termination impedance 10 7.4 Maximum aggregate transmit power 11 8 Transmit PSD verification 11 Annex A to Annex W. 12 Annex X Adaptation to the coax medium . 13 X.1 Profile control parameters 13 X.2 Termination impedance 13 X.3 Maximum aggregate transmit power 13 Appendix I Int
23、ernational amateur radio bands 15 Appendix II Broadcast radio bands . 16 Appendix III Definition of transmitter PSD (TXPSD) for non-continuous transmissions . 17 Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) 1 Recommendation ITU-T G.9700 Fast access to subscriber terminals (G.fast) Power spectral density
24、 specification Amendment 2 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
25、 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 impeda
26、nce; 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
27、 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
28、 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 refe
29、rence 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
30、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
31、of subcarrier spacing. 2 Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) 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
32、may be modulated for transmission over a channel. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: DAB Digital Audio Broadcasting DMT Discrete Multitone DP Distribution Point DSL Digital Subscriber Line EMC Electromagnetic Compatibility FAST (G.fast) Fa
33、st Access to Subscriber Terminals FM Frequency Modulation FTU FAST Transceiver Unit FTU-O FTU at the Optical network unit FTU-R FTU at the Remote site (i.e., subscriber end of the loop) LESM Low-frequency Edge Stop-band Mask LPM Limit PSD Mask MBW Measurement Bandwidth MIB Management Information Bas
34、e NM Notching Mask PSD Power Spectral Density PSM PSD Shaping Mask QoS Quality of Service SM Subcarrier Mask TDD Time-Division Duplexing TxPSDM Transmit PSD Mask 5 Conventions None. 6 Transmit PSD mask 6.1 Overview The transmit PSD mask (TxPSDM) is constructed from the combination of the following m
35、asks: limit PSD mask (LPM); subcarrier mask (SM); PSD shaping mask (PSM); notching mask (NM); and low-frequency edge stop-band mask (LESM). Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) 3 The TxPSDM applied to the FAST transceiver unit (FTU) at the optical network unit (FTU-O) or at the FTU remote site (
36、i.e., subscriber end of the loop) (FTU-R) may be different. For an FTU, the PSD of the transmit signal at any frequency shall never exceed the TxPSDM. The LPM (see clause 7.2.1) specifies the absolute maximum limit of the TxPSDM. The subcarrier mask (SM), PSD shaping mask (PSM), notching mask (NM) a
37、nd low-frequency edge stop-band mask (LESM) provide reduction and shaping of the TxPSDM using four mechanisms: subcarrier masking; notching of specific frequency bands; PSD shaping; and low-frequency edge stop-band masking. Support of these four mechanisms is mandatory in both the FTU-O and the FTU-
38、R. The TxPSDM shall comply with applicable national and regional regulatory requirements. NOTE 1 When determining the correct PSD to use in a particular jurisdiction, operators should use tools provided to ensure compliance with national and regional electromagnetic compatibility (EMC) regulations g
39、iving special consideration to protecting receivers for the safety of life services which may not be immediately adjacent to the drop wires carrying ITU-T G.9701 signals. Examples include various VHF aeronautical radio navigation channels in the band 108-117.975 MHz, and aeronautical emergency commu
40、nications channels (e.g., 121.5 MHz) and maritime emergency communications channels in the HF and VHF bands. NOTE 2 In addition to the masks defined in this Recommendation that provide absolute limits to the TxPSDM (both in-band and out-of-band), ITU-T G.9701 defines two mechanisms: a mechanism of d
41、iscontinuous operation that allows the FTU to dynamically switch off the transmit power in each particular connection when no data is present for transmission and a mechanism of low power mode (L2). Both mechanisms allow the system to further reduce the transmit power to a value that is sufficient t
42、o achieve the given bit rate and quality of service (QoS) targets. NOTE 3 TXPSDM is defined in various averaging bandwidths according to frequency as defined in Table 8-1, except in sub-bands at the low frequency band edge and in the region of MIB defined notches, where TXPSDM_W (1 MHz wideband) and
43、 TXPSDM_N (10 kHz narrowband) masks apply as described in clauses 6.5 and 6.6. 6.2 Limit PSD mask (LPM) The limit PSD mask (LPM) defines the absolute maximum PSD limit of the TxPSDM that shall never be exceeded. All the other mask definitions and mechanisms used to construct the TxPSDM can only resu
44、lt in a reduction of the mask from the limits established by the LPM. 6.3 Subcarrier masking Subcarrier masking shall be used to eliminate transmission on one or more subcarriers. The subcarrier mask (SM) is configured in the distribution point management information base (DP-MIB) by use of the ITU-
45、T G.997.1 parameter CARMASK. The transmit power of subcarriers specified in the SM shall be set to zero (linear scale). The SM shall override all other instructions related to the transmit power of the subcarrier. The SM is defined as a number of masked frequency bands. Each band is specified by a s
46、tart subcarrier index (xL) and a stop subcarrier index (xH), as xL, xH. An SM including S bands can be represented in the following format: SM(S) = xL1, xH1, xL2, xH2, x LS, xHS All subcarriers within the band, i.e., with indices higher than or equal to xL and lower than or equal to xH, shall be swi
47、tched off (transmitted with zero power). NOTE The SM is intended to incorporate both masked subcarriers that are defined by an annex defining regional requirements so as to comply with local regulations and masked subcarriers that are defined by the 4 Rec. ITU-T G.9700 (2014)/Amd.2 (06/2017) user or
48、 service provider to facilitate local deployment practices. Protection of radio services is not intended to be addressed by subcarrier masking; it is addressed by notching (see clause 6.5). 6.4 Power spectral density shaping Power spectral density (PSD) shaping allows reduction of the TxPSDM in some
49、 parts of the spectrum, mainly for spectrum compatibility and coexistence with other access and home network technologies. The PSD shaping mask (PSM) is configured in the DP-MIB by use of the ITU-T G.997.1 parameter PSDMASK. The PSM is defined on the frequency range between the lowest subcarrier x1 (with x1=ceiling(ftr1/fSC) and the highest subcarrier xH (with xH=floor(ftr2/ fSC), and consists of one or more frequency
