1、 ATIS-0600012.04 ATIS Standard on - Electrical Protection for Fast Access to Subscriber Terminals (G.fast) As a leading technology and solutions development organization, the Alliance for Telecommunications Industry Solutions (ATIS) brings together the top global ICT companies to advance the industr
2、ys most pressing business priorities. ATIS nearly 200 member companies are currently working to address the All-IP transition, 5G, network functions virtualization, big data analytics, cloud services, device solutions, emergency services, M2M, cyber security, network evolution, quality of service, b
3、illing support, operations, and much more. These priorities follow a fast-track development lifecycle from design and innovation through standards, specifications, requirements, business use cases, software toolkits, open source solutions, and interoperability testing. ATIS is accredited by the Amer
4、ican National Standards Institute (ANSI). The organization is the North American Organizational Partner for the 3rd Generation Partnership Project (3GPP), a founding Partner of the oneM2M global initiative, a member of the International Telecommunication Union (ITU), as well as a member of the Inter
5、-American Telecommunication Commission (CITEL). For more information, visit www.atis.org. Notice of Disclaimer European Requirements for Reverse Powering of Remote Access Equipment.102.2 Informative References 101 IEEE 802.3, IEEE Standard for Information technology Telecommunications and informatio
6、n exchange between systems Local and metropolitan area networks.2 1This document is available from UL. 2This document is available from the Institute of Electrical and Electronics Engineers (IEEE). 3This document is available from the International Telecommunications Union. 4This document is availab
7、le from Telcordia. . 5This document is available from the National Fire Protection Association. . The National Electrical Code and NEC are registered trademarks of the National Fire Protection Association, Quincy, MA. 6This document is available from the IEEE. . The National Electrical Code and NEC
8、are registered trademarks of the National Fire Protection Association, Quincy, MA. 7This document is available from the Alliance for Telecommunications Industry Solutions (ATIS), 1200 G Street N.W., Suite 500, Washington, DC 20005. 8This document is available from ATIS. . 9This document is available
9、 from the International Electrotechnical Commission (IEC) 10This document is available from the European Telecommunications Standards Institute (ETSI). ATIS-060012.04 3 102 IEC 61643-351, Low-Voltage Surge Protective Components - Part 361: Lightning isolation transformers (LIT) connected to telecomm
10、unications and signaling networks-Performance requirements and testing methods.9 103 ITU-T K.95, Series K: Protection Against Interference - Surge parameters of isolating transformers used in telecommunication devices and equipment.11 104 ITU-T G.9701, Series G: Transmission Systems and Media, Digit
11、al Systems and Networks.11 3 Definitions, Acronyms, typically 5 ns rise time, with a duration of 50 ns in 15 ms bursts. 3.1.2 G.fast: A DSL-like technology that uses Time Division Duplex (TDD) techniques with bandwidths up to106 mHz (may be increased to 212 mHz). See Annex B for more details. 3.1.3
12、Ground symbols: 11This document is available from the International Telecommunications Union (ITU). ATIS-060012.04 4 Identified ground (user defined as analog/digital/signal/logic, etc.). Earth ground is often used in schematics as signal ground or identified ground. 3.1.4 Line side: Outside plant c
13、able side of the signal transformer (see diagram below). Figure 3.1 Illustration of Line Side of Signal Transformer 3.1.5 PHY: The “Physical interface“ Integrated Circuit that drives and receives the G.fast signal through or from the transformer to the line. A PHY chip (PHYceiver) is commonly found
14、on G.fast devices. Its purpose is physical, analog signal access to the link. It is usually used in conjunction with a Media Independent Interface (MII) chip or interfaced to a microcontroller that takes care of the higher layer functions. 3.1.6 Saturation (transformer): A condition wherein addition
15、al input voltage or current results in no output from the transformer. 3.1.7 Secondary Protection: Over voltage protection (OVP), typically located on the cable side of the signal transformer if an over current protector (OCP) is used, the secondary over voltage protector should be between the OCP a
16、nd the signal transformer. Other standards may define secondary protectors differently. 3.1.8 Tertiary Protection: Over voltage protection typically located between the coupling transformer and the line driver (PHY in this document). 3.2 Acronyms AC (ac) Alternating Current ADSL2 Asymmetric Digital
17、Subscriber Line 2 ATIS-060012.04 5 ANSI American National Standards Institute ATIS Alliance for Telecommunications Industry Solutions BET Building Entrance Terminal CBN Common Bonding Network (also known as an integrated ground plane) CO Central Office CPE Customer Premises Equipment dB Decibel dBm
18、Decibels referenced to 1 milliwatt DC (dc) Direct Current DCR Dropped Call Rate DSL Digital Subscriber Line EPR Earth Potential Rise EFT Electrical Fast Transient ESD Electrostatic Discharge Event EUT Equipment Under Test (aka Device Under Test) FDD Frequency Division Duplex G.fast ITU-T (G.9701) 10
19、4 Fast Access to Subscriber Terminals GDT Gas Discharge Tube GPR Ground Potential Rise Hz Hertz IEC International Electrotechnical Commission IEEE Institute of Electric and Electronic Engineers iNID Intelligent Network Interface Device kHz Kilohertz LIT Lightning Isolation Transformer mHz Megahertz
20、MII Media Independent Interface mW Milliwatt NEC National Electrical Code NESC National Electrical Safety Code NID Network Interface Device NIU Network Interface Unit OCP Over Current Protector OFDM Orthogonal Frequency Division Multiplexing ONT Optical Network Terminal ONU Optical Network Unit OSP
21、Outside Plant ATIS-060012.04 6 OVP Over Voltage Protection PCB Printed Circuit BoardPEC Parallel Earth Conductor PoE Power over Ethernet POTS Plain Old Telephone Service PSD Power Spectral Density RF Radio Frequency rms Root-Mean-Square RT Remote Terminal SAD Silicon Avalanche Diode SELV Safety Extr
22、a Low Voltage SPA Silicon Protection Array STP Shielded Twisted Pair TDD Time Division DuplexTNV Telecommunication Network Voltage TSTC Telecommunication Safety Technical (IEEE) Committee TVS Transient Voltage Suppressor UL Underwriters LaboratoriesUPS Uninterruptable Power Supply UTP Unshielded Twi
23、sted Pair VDC Volts of Direct Current VDSL2 Very High Speed Digital Subscriber Line 2 Vrms Root Mean Squared Voltage xDSL Any type of DSL Technology (x=type) ZOI Zone of Influence 4 Description of G.fast 4.1 Standard G.fast G.fast has a targeted data rate of 1 Gbps over 100 m (with lower data rates
24、having higher reaches, see Table 4.1) over a single twisted pair of 24 AWG (0.5 mm) conductors in a cable using a Digital Subscriber Line (DSL)-like technology. Conductors of other wire gauges may be used that increase or reduce rate and reach. G.fast is based on TDD signaling, which is a major diff
25、erence from the existing Frequency Division Duplex (FDD) “x” Digital Subscriber Line (xDSL) signaling. The G.fast bandwidth will extend up to 106 MHz as shown in Figure 4.1 below with a second bandplan extending it up to as high as 212 MHz. The start frequency will be selected in an effort to avoid
26、interference with existing xDSL services. It may also employ “notching”, which is suppression of specific individual frequencies to avoid clashing with local Radio Frequency (RF) services. ATIS-060012.04 7 Figure 4.1 Spectrum View Table 4.1 G.fast Rate and Reach Targets Distance Rate Aggregate data
27、rates over 0.5 mm (24 AWG) wire size 50 m 500 Mbps (in presence of RFI) 100 m 500 to 1000 Mbps 100 m 500 Mbps 200 m 200 Mbps 250 m 150 Mbps ATIS-060012.04 8 Figure 4.2 G.fast with Reverse Powering Overview G.fast may: 1. Be user installed. 2. Be customer premises-powered. 3. Need Over Voltage Protec
28、tor (OVP) for twisted pair (both data pair and power pair), Outside Plant (OSP) equipment, and CPE. Plain Old Telephone Service (POTS) and ringing voltages, if present, must be considered. 4.2 G.fast Powering NOTE: See Figure 4.2. The applicable code requirements for G.fast powering in North America
29、 include Chapter 8 of NFPA 70, the National Electrical Code (NEC) 6, and applicable National Electrical Safety Code (NESC) 7 Rules 224 and 344 providing the power, voltage, and currents remain within the accepted limits of the communications industry i.e., Class A2 voltages (as per GR-1089-CORE 5) w
30、ith power limited to less than 100 VA. ATIS-6000337, Requirements for Maximum Voltage, Current and Power Levels Used in Communications Transport Circuits 8, also provides guidance on the voltage and currents that would be used for powering G.fast. International requirements for reverse powering are
31、contained in ETSI TS 101 548 v1.1.113, which require it to comply with TNV3 limitations from IEC 60950-1 1 (equivalent to ES2 in IEC 62368-1 2). 4.2.1 G.fast Systems Utilizing Network Power on the Twisted Pairs Network-side power to the Optical Network Unit (ONU) or other service provider transceive
32、r equipment is not covered in this document. Please see ATIS-0600030 10, Standard for Line P owering of Telecommunication Equipment on O utside Plant Twisted Copper Pair Loops, for additional information. ATIS-060012.04 9 4.2.2 G.fast Systems Utilizing Reverse Powering on the Twisted Pair The revers
33、e powering options described in this section are for a system architecture where the power is supplied from the end customer location to a distribution point where it provides powering for the G.fast communication equipment. Code requirements are found in Chapter 8 of the NEC 6 and in applicable NES
34、C 7 rules. The power, voltage, and currents must remain within the TNV3 or ES2 limits of the safety standards (e.g., IEC/UL 60950-1 1, UL/IEC 62368-1 2. GR-1089-CORE 5 and ATIS-0600337 8 harmonize with these safety standards. TNV3 and ES2 have a 60V dc maximum limit in North America. TNV3 and ES2 ha
35、ve a 120V dc maximum limit internationally. Power is limited to 100VA in North America and internationally. The reverse power architectures will need to meet the applicable NEC 6 requirements of Section 840.160. Considerations will need to be made to help ensure adequate and consistent grounding and
36、 bonding practices that are in compliance with objectives of NEC Article 250, Article 110, and Chapter 3, as well as other pertinent articles as the immediate circumstances, customer locations, and physical layouts demand. The wiring methods at the customer location should be reviewed for compliance
37、 to these requirements. A consistent approach of the intersystem bonding and continuity of grounding connections will need to be established. Coordination will be needed for: Grounds and earth connections. Avoid voltage differentials and undesirable current flows in the case of a Ground Potential Ri
38、se (GPR) event by implementing a single point grounding system. Intersystem bonds and connection points. Avoid ground voltage differentials and undesirable current flows by implementing a single main ground point at the building entrance, NID, or power service entry (meter). Primary/secondary/tertia
39、ry protection devices and components for communications circuits, power circuits, and other circuits for the system. The telecommunications circuits for line powering are designed to meet industry safety standards such as UL 60950-1 1, 60950-21 9, and GR-1089-CORE 5 as well as the NESC 6 /NEC 7 safe
40、ty codes. The circuits are designed to limit the amount of power that can be transmitted per each twisted pair circuit (i.e., the bonded multi-pair circuit, not just per pair to 100 VA), and operate in the voltage ranges shown in Table 4.2. Table 4.2 Recommended Voltage Operating Windows for Line-Po
41、wered Equipment Nominal Line-Powering Source-End Voltage Operational Voltage Window Requirement for the End-Use Equipment Wide Range Maximum Operating Voltage Requirement for the End-Use Equipment Wide Range Minimum Operating Voltage Requirement for the End-Use Equipment -48 VDC1-30 to -56 -60 -27 -
42、130 VDC -70 to -140 -150 -65 130 VDC 70 to 140 (140 to 280 across pairs) 150 (300 across pairs) 65 (130 across pairs) -190 VDC -100 to -195 -200 -95 ATIS-060012.04 10 Nominal Line-Powering Source-End Voltage Operational Voltage Window Requirement for the End-Use Equipment Wide Range Maximum Operatin
43、g Voltage Requirement for the End-Use Equipment Wide Range Minimum Operating Voltage Requirement for the End-Use Equipment 190 VDC 100 to 195 (200 to 390 across pairs) 200 95 (190 across pairs) NOTES: 1. The -48 VDC line-powering source referenced here excludes legacy POTS circuits and PoE (voltage
44、operating windows for PoE are defined in IEEE 802.3 101). 2. This table is sourced from ATIS-0600030 10. . 5 G.fast Protection Topologies 5.1 Grounding therefore, the majority of surge current will be conducted from an external port to ground. Therefore, it is only necessary to perform line-to-line
45、and port-to-ground tests on the external ports of the equipment. For grounded equipment, a significant current may be conducted from both port to ground and port to port. Therefore, it will be necessary to perform line-to-line, port-to-ground and port-to-port tests. For floating access network equipment, while substantial current is conducted port to port on the external ports of the equipment, it is still necessary to perform port-to-ground tests as well.
