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 L.1315 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2017) SERIES L: ENVIRONMENT AND ICTS, CLIMATE CHANGE, E-WASTE, ENERGY EFFICIENCY; CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE
2、PLANT Standardization terms and trends in energy efficiency Recommendation ITU-T L.1315 ITU-T L-SERIES RECOMMENDATIONS ENVIRONMENT AND ICTS, CLIMATE CHANGE, E-WASTE, ENERGY EFFICIENCY; CONSTRUCTION, INSTALLATION AND PROTECTION OF CABLES AND OTHER ELEMENTS OF OUTSIDE PLANT OPTICAL FIBRE CABLES Cable
3、structure and characteristics L.100L.124 Cable evaluation L.125L.149 Guidance and installation technique L.150L.199 OPTICAL INFRASTRUCTURES Infrastructure including node element (except cables) L.200L.249 General aspects and network design L.250L.299 MAINTENANCE AND OPERATION Optical fibre cable mai
4、ntenance L.300L.329 Infrastructure maintenance L.330L.349 Operation support and infrastructure management L.350L.379 Disaster management L.380L.399 PASSIVE OPTICAL DEVICES L.400L.429 MARINIZED TERRESTRIAL CABLES L.430L.449 For further details, please refer to the list of ITU-T Recommendations. Rec.
5、ITU-T L.1315 (05/2017) i Recommendation ITU-T L.1315 Standardization terms and trends in energy efficiency Summary Recommendation ITU-T L.1315 provides a high-level definition of energy efficiency, energy management requirement to increase the energy efficiency of information and communication techn
6、ology (ICT) goods, networks and services. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T L.1315 2017-05-24 5 11.1002/1000/13145 Keywords Energy efficiency, methodology, metrics. * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your
7、web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T L.1315 (05/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and commun
8、ication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ 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
9、 World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the 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
10、. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are 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 r
11、ecognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation 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. T
12、he words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used 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
13、 that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual 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 Recomme
14、ndation development process. As of the date of approval of this Recommendation, ITU /had not received notice 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
15、and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 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 L.1315 (05/2017) iii Table of Contents Pa
16、ge 1 Scope . 1 2 References . 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 1 4 Abbreviations and acronyms 2 5 Conventions 2 6 Energy efficiency 2 6.1 General concept 2 6.2 Energy efficiency for ICT 3 6.3 Energy efficiency hierarchy . 4 7 Useful work conc
17、ept for ICT 4 8 Energy management . 5 9 Renewable energy sources 6 10 Functioning status/mode and EE 6 11 General measurement conditions 7 11.1 Environmental considerations 7 11.2 Voltage . 7 11.3 Power source 8 11.4 Power measurement equipment 8 Bibliography. 9 iv Rec. ITU-T L.1315 (05/2017) Introd
18、uction This Recommendation was developed jointly by ETSI TC EE and ITU-T Study Group 5 and published respectively by ITU and ETSI as Recommendation ITU-T L.1315 and ETSI Standard ETSI ES 203 475, which are technically equivalent.Rec. ITU-T L.1315 (05/2017) 1 Recommendation ITU-T L.1315 Standardizati
19、on terms and trends in energy efficiency 1 Scope This Recommendation specifies terminology, principles and concepts for energy efficiency and energy management. The Recommendation establishes a common understanding on measurement methodology used to determine the energy efficiency of a good, service
20、 and network. It is a framework for other ITU-T standards and other standard development organization (SDO) document for energy efficiency thematic. 2 References The following Recommendations contain provisions, which, through reference in this text, constitute provisions of this Recommendation. At
21、the time of publication, the references editions indicated are valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to check for latest published documents and using the most recent edition of the Recommendations and other ref
22、erences 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 L.1310 ITU-T L.1310 (2014), Energy efficiency metrics and measur
23、ement methods for telecommunication equipment. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 active mode ITU-T L.1310: For small networking equipment, this is the operational mode where all ports (WAN and LAN) are connected, with at l
24、east one Wi-Fi connection, if a Wi-Fi function is available. 3.1.2 energy ITU-T L.1310: “The capacity for doing work“. In the telecommunication systems, where the primary source of energy is electricity, energy is measured in Joules. 3.1.3 idle mode ITU-T L.1310: For small networking equipment, this
25、 means the same as active mode, but with no user data traffic (it is not zero traffic, as service and protocol supporting traffic are present) being used, although it is ready to be used (U1 in routers part). 3.1.4 low power (sleep) mode ITU-T L.1310: For small networking equipment, this means a sta
26、te that happens after the device detects no user activity for a certain period of time and reduces energy consumption. For this state, no user-facing LAN ports are connected; the Wi-Fi is active but no clients are connected. The WAN port may be inactive. The device will reactivate on detecting a con
27、nection from a user port or device. 3.2 Terms defined in this Recommendation 3.2.1 functional unit: (based on ITU-T L.1310 A performance representation of the system under analysis. For example, for transport equipment, the functional unit is the amount of data 2 Rec. ITU-T L.1315 (05/2017) transmit
28、ted, the distance over which it is transported and its rate in Gbit/s. Sometimes the term is used to represent useful output or work. 3.2.2 small networking device: (based on ITU-T L.1310) A networking device with fixed hardware configuration, designed for home/domestic or small office use, with les
29、s than 12 wired ports. This device can have wireless functionality implemented. Wireless functionality is not considered a port. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: AC Alternating Current CRT Cathode Ray Tube EE Energy Efficiency EER Energy
30、 Efficiency Rating EUT Equipment Under Test ICT Information and Communication Technology LAN Local Area Network LCD Liquid Cristal Display LED Light Emitting Diode PUE Power Usage Effectiveness (for data centre) SDO Standards Development Organization WAN Wide Area Network 5 Conventions Efficiency 6
31、Energy efficiency 6.1 General concept Energy efficiency is a widely used term that has multiple meanings, and can be used in contexts such as use the stairs, be energy efficient, and also in reference to an energy efficient office or house, or in many other contexts. In the context of electrical dev
32、ices, as a starting point, the following is a generic definition for energy efficiency applicable to energy converting devices: =Energyoutput /Energyinput (6-1) “Energy Efficiency“ that applies to any device that uses energy to do work can be defined as: “The percentage of total energy input to a ma
33、chine or equipment that is consumed in useful work and is not wasted as useless heat“. This could be expressed as follows: = (6-2) Rec. ITU-T L.1315 (05/2017) 3 By definition, “Energy Efficiency“ is always in the range from 0 to 1, or 0 to 100% (if expressed as a percentage). The goal of increasing
34、energy efficiency (EE) is to realize solutions that will give the same or better functionality using less energy. For IT equipment, output energy does not represent useful output energy. Therefore, energy efficiency for IT equipment shows how much energy is used to perform a functional unit (which i
35、s specific for the device or solution). This key performance indicator (KPI) ratio can be called EER to distinguish it from EE. EE increase is one of many ways of managing and restraining the growth in energy consumption. A device is more energy efficient if it delivers more services for the same en
36、ergy input, or the same services for less energy input. For example, when a light emitting diode/liquid crystal display (LED/LCD) uses less energy than a traditional display based on cathode ray tube (CRT) to reproduce the video, the display is considered to be more energy efficient. The goal of ene
37、rgy efficiency increase is to provide solutions that will support more functionalities while using less energy. A trivial solution for the maximum energy saving can be achieved by simply switching off the device but that will eliminate the service delivered by the device. Likewise, EE will be zero a
38、s a result. This is the major reason for which the energy efficiency (EE and EER) of an equipment should be considered, and not only its energy consumption. Energy efficiency is not an absolute metric, which implies that to compare two pieces of equipment, these must be of the same type and with sim
39、ilar functionality. Energy efficiency (EE and EER) increase is important at all stages of the energy chain from generation to final consumption. Eventually the benefits of energy efficiency (EE and EER) increase will outweigh the costs, for instance, renovation costs. Energy efficiency is not equal
40、to energy conservation. Energy conservation is reducing or going without a service to save energy. The formula below shows the power usage effectiveness (PUE) concept equivalent to EE applicable to data centres: = (6-3) It is noted that in reality, formula (6-3) gives a ratio between two power value
41、s, which is an indication of energy efficiency (EE and EER). Technically, energy is the integral of the power in a time window, so it is possible to consider measuring energy efficiency as the ratio between two powers without any error only if the powers considered are constant during the time integ
42、ration window. 6.2 Energy efficiency for ICT When the energy efficiency (EE and EER) concept is applied to the information and communication technology (ICT) world, it is not possible to make reference to output to power or energy, and it is important to introduce the concept of a proxy for “useful
43、work“, changing formula (6-1). In this case the energy efficiency rating of functionality shall be expressed as the ratio between the expected result normally called a proxy for useful work (similar to functional unit) and the energy used to realize that functionality. The new formula will be: = (6-
44、4) This formula in this case is not a ratio between two values with the same units, but between two different characteristics, so the indicator of efficiency realized will not be a pure number but a ratio between useful work and energy. The measurement unit will be different depending on the useful
45、4 Rec. ITU-T L.1315 (05/2017) work selected for the service or equipment under test (EUT) e.g., bit/J in the case where the useful work is a throughput measured in bit/s. In order to easily measure the energy efficiency (EE and EER) in the case of equipment without a big variation of energy consumpt
46、ion, it is preferable to measure the power of an equipment, in place of the energy. In this case the power will not be an instantaneous power but a power averaged in a time frame to eliminate the fluctuation of the instantaneous power measurements. In the latter case of energy efficiency given above
47、 (formula 6-3), energy efficiency is expressed with the same terminology but using total power and not total energy in the numerator of the formula. The energy efficiency rating (EER) is a device metric defined as a functional unit divided by the power. Various types of equipment have their own EER
48、definitions. 6.3 Energy efficiency hierarchy An energy efficiency metric can be defined at different levels as follows: network/solution level equipment/system level component level In standardization, only metrics at network, and equipment or system level are normally considered, defined and used t
49、o test or evaluate the energy efficiency of the equipment or system. Metrics at the component level are given as suggestions only and could be used as a tool to improve the efficiency of an equipment. 6.3.1 Energy efficiency at the network level Network level metrics are used to evaluate the energy efficiency of an entire network or
