1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Y.3021TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2012) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Future networks Framework of energy saving for Future Networks CAU
2、TION ! PREPUBLISHED RECOMMENDATION This prepublication is an unedited version of a recently approved Recommendation. It will be replaced by the published version after editing. Therefore, there will be differences between this prepublication and the published version. Copyright International Telecom
3、munication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo
4、 reproduction or networking permitted without license from IHS-,-,-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
5、 (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 World Telecommunication Standardization Assembly (WTSA), which meets every f
6、our 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. In some areas of information technology which fall within ITU-Ts purview, t
7、he 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 recognized operating agency. Compliance with this Recommendation is voluntary.
8、 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. The words “shall“ or some other obligatory language such as “must“ and the neg
9、ative 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 RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the
10、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 Recommendation development process. As of the date of approval of this Recommendati
11、on, ITU had/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 and are therefore strongly urged to consult the TSB patent database at ht
12、tp:/www.itu.int/ITU-T/ipr/. ITU 2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for R
13、esaleNo reproduction or networking permitted without license from IHS-,-,-Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Rec. ITU-T Y.3021 (01/2012)
14、 Prepublished version 1 Recommendation ITU-T Y.3021 Framework of energy saving for Future Networks Summary This Recommendation describes the framework of energy saving for Future Networks (FNs). It first describes the need for energy saving of networks themselves, and reviews potential technologies.
15、 The document then identifies major functions and their cyclic interactions, analyses possible impacts of introducing the technologies, and itemises the high-level requirements for introducing the technologies. Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by I
16、HS under license with ITU-TNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Rec. ITU-T Y.3021 (01/2012) Prepublished version 2 Table of Contents 1 Scope 2 References 3 Definitions 3.1 Terms defined elsewhere 3.2 Terms defined in this Recommendation 4 Abbreviations a
17、nd acronyms 5 Conventions 6 Introduction 6.1 Background and motivation 6.2 Lifecycle stages and levels to be considered 7 Review of energy saving technologies 7.1 List of technologies and their levels 7.2 Device-level technologies 7.3 Equipment-level technologies 7.4 Network-level technologies 8 Con
18、siderations for energy saving 8.1 Target areas of this Recommendation 8.2 Approaches for energy saving 8.3 Controlling device/equipment operation according to traffic dynamics 8.4 Forwarding traffic with less power 8.5 Classification of individual technologies 9 Possible functions and their interact
19、ions 9.1 Possible functions 9.2 Combination models of functions 10 Impact analysis of energy saving 10.1 Influence on network performance 10.2 Influence on service provisioning 11 High level requirements 12 Environmental considerations 13 Security considerations Bibliography Copyright International
20、Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Rec. ITU-T Y.3021 (01/2012) Prepublished version 3 Recommendation ITU-T Y.3021 Framework of energy saving for Future Networks
21、 1 Scope This Recommendation - Describes the necessity for energy saving, - Reviews potential technologies, - Identifies multiple viewpoints to be considered, - Identifies major functions and their cyclic interactions, - Analyses possible impacts by introducing the technologies, and - Itemises high-
22、level requirements to achieve energy saving of Future Networks (FNs). The framework and ideas described in this Recommendation may also be applicable and useful for networks which are not categorised as Future Networks, although the description is produced through full recognition of the objectives
23、and design goals of Future Networks ITU-T Y.3001. 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 Recommend
24、ations 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 pub
25、lished. 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.1400 Recommendation ITU-T L.1400 (2011), Overview and general principles of methodologies for assessing the environmental impact of ICT. ITU-T Y.3001 Re
26、commendation ITU-T Y.3001 (2011), Future Networks: Objectives and Design Goals. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 Future Network (FN) ITU-T Y.3001: A network able to provide services, capabilities, and facilities difficult
27、 to provide using existing network technologies. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 device: Material element or assembly of such elements intended to perform a required function. 3.2.2 energy saving of networks: Network capabilities and th
28、eir operations where the total energy for network equipment is systematically used in an efficient manner and, as a consequence, Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo reproduction or networking permitted w
29、ithout license from IHS-,-,-Rec. ITU-T Y.3021 (01/2012) Prepublished version 4 the energy consumption is reduced compared with networks without those capabilities and operations. NOTE Network equipment includes routers, switches, equipment at the terminating point e.g., Optical Network Units (ONUs),
30、 home gateways, and network servers such as load balancers and firewalls. Network equipment is typically composed of various components such as switching fabric, line cards, power supply, and cooling. 3.2.3 equipment: Set of devices assembled together to form a physical entity to perform a specific
31、task. 3.2.4 network energy efficiency: Throughput of the network divided by the power consumed. NOTE It is usually expressed in bps/W. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: ALR Adaptive Link Rate BTS Base Transceiver Station CAM Content Addre
32、ssable Memory CAPWAP Control and Provisioning of Wireless Access Points CPU Central Processing Unit DDoS Distributed Denial-of-Service DPD Digital Pre-Distortion DVS Dynamic Voltage Scaling FN Future Network GHG GreenHouse Gas HVHBT High Voltage Heterojunction Bipolar Transistor ICT Information and
33、Communication Technology LSI Large Scale Integration MIMO Multiple Input, Multiple Output MPLS Multi-Protocol Label Switching NIC Network Interface Card ONU Optical Network Unit PA Power Amplifier PC Personal Computer SINR Signal to Interference and Noise Ratio SISO Single-Input Single-Output SLA Se
34、rvice Level Agreement SRAM Static Random Access Memory UE User Equipment WLAN Wireless Local Area Network Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo reproduction or networking permitted without license from IHS
35、-,-,-Rec. ITU-T Y.3021 (01/2012) Prepublished version 5 5 Conventions None. 6 Introduction 6.1 Background and motivation Energy saving in the information and communication technology (ICT) field is an important issue, as has been identified in designing Future Networks ITU-T Y.3001. One of the basic
36、 objectives of Future Networks is environmental awareness, and energy saving is one of the technologies used to realise this. Historically, energy saving has been studied for individual users or companies own benefits, namely the reduction of energy costs and suppression of heat for stable machine o
37、peration. The importance of these issues is increasing as the performance of network equipment improves due to denser implementation and higher energy consumption. Currently it is also becoming important from the social perspective, specifically to support the reduction of greenhouse gas (GHG) emiss
38、ions. These issues will gain more importance in the future. This Recommendation therefore studies potential technologies and their coordinated operation, which will contribute to saving energy and to various other objectives. Contribution of ICT to reducing the environmental impact is often categori
39、sed into Green by ICT and Green of ICT. Green by ICT is a challenge to reduce the environmental impact in non-ICT sectors by using ICT. Green of ICT is a challenge to reduce the environmental impact of the ICT itself such as the reduction of electric power consumption of personal computers (PCs), se
40、rvers, and routers. The contribution of Future Networks to reducing environmental impact can therefore be categorised in the same manner as shown below. - Green by Future Networks A challenge to reduce environmental impact in non-ICT sectors by using Future Networks. Future Networks must become a us
41、eful tool for reducing the environmental impact of other sectors. Network architecture designed for smart grids for electric power distribution, or ubiquitous sensor networks that monitor environmental changes of the Earth are a few examples of contributions of Green by Future Networks. - Green of F
42、uture Networks A challenge to reduce environmental impact of Future Networks. The fundamental principle for the Future networks is that they must have minimum impact on the environment. As described above, the use of networks is considered a prospective means to reduce the environmental impact of ot
43、her sectors. Yet by doing so, it increases the volume of traffic flowing into networks, increases energy consumption of the networks accordingly, and then increases the environmental impact. Reducing the energy consumption of network facilities such as routers, switches, and servers is a direct exam
44、ple of contributions of Green of Future Networks. Each issue is important, but this Recommendation focuses on Green of Future Networks, which means energy saving of networks themselves, because energy consumption of networks is rapidly increasing as the applications on networks increases. 6.2 Lifecy
45、cle stages and levels to be considered To reduce energy consumption, it is important to analyse energy consumption at each stage in the lifecycle. In life cycle management, the following stages are typically used for analysis, for example in ITU-T L.1400. - Production (preparing raw materials and co
46、mponents for the target) Copyright International Telecommunication Union/ITU Telcommunication Sector Provided by IHS under license with ITU-TNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Rec. ITU-T Y.3021 (01/2012) Prepublished version 6 - Manufacturing - Use - D
47、isposal/recycling In the case of networks, these stages are explained as follows. Regarding the first stage, production, preparation of raw materials for small electronics devices and composition of the equipment are included. The second stage, manufacturing, includes constructing a network by means
48、 of the equipment. For network construction, relevant pieces of equipment are transported from a manufacturers site to the construction location. Then comes the third stage, use, to operate the equipment. After the end of the service life of the network, the network including all equipment would be disposed and/or recycled in the fourth stage, disposal/recycling. Life cycle management considers all of these stages. In the case of networks, however, the third stage, use, is primarily considered because energy consumption in the “use“ stage is usually the major issue for always-o
