ATIS 0600012 05-2017 Electrical Protection for Ethernet Systems.pdf

1、 ATIS-0600012.05 ATIS Standard on - Electrical Protection for Ethernet Systems 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 industrys most pressing business pr

2、iorities. 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, billing support, operations,

3、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 American National Standards Inst

4、itute (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-American Telecommunication

5、Commission (CITEL). For more information, visit www.atis.org. Notice of Disclaimer the initial cable charge may be caused by triboelectric (friction) effects that may occur as enhanced CAT5/5e or CAT6 cables that exhibit low leakage are dragged across a floor/carpet or simply having air movement acr

6、oss them or induction from adjacent electromagnetic fields. Their low leakage causes them to retain these charges for long periods of time. 3.1.2 Diode: A semi-conductor device that conducts current in only one direction under normal conditions. 3.1.3 Earth: See ground definition. 3.1.4 Electrical F

7、ast Transient (EFT): Events that have high amplitude, short rise time, high repetition rate, and low energy content as described in IEC 61000-4-4; typically 5ns rise time, with a duration of 50ns in 15 ms bursts. 3.1.5 Ground: Identified ground (user defined as analog/digital/signal/logic, etc.). Ea

8、rth ground is often used in schematics as signal ground or identified ground. 3.1.6 High Exposure Environment: See Clause 9 for explanation. ATIS-0600012.05 9 3.1.7 Internal Ethernet Port: Ethernet port that remains within the building (see External Ethernet Port) or does not extend beyond a short d

9、istance from the building (for example, the distance from an optical network terminal (ONT) port(s) to the entrance point of the served building). 3.1.8 Low Exposure Environment: See Clause 9 for explanation. 3.1.9 PHY: The “Physical interface“ Integrated Circuit that drives and receives the Etherne

10、t signal through or from the transformer to the line. A PHY chip (PHYceiver) is commonly found on Ethernet 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

11、 care of the higher layer functions. 3.1.10 Saturation (transformer): A condition wherein additional input voltage or current results in no additional output from the transformer. 3.1.11 Secondary Protection: Overvoltage protection typically located on the cable side of the signal transformer (If an

12、 overcurrent protector is used, the secondary overvoltage protector should be between the OCP and the signal transformer.) Other standards may define secondary protectors differently. 3.1.12 Tertiary Protection: Overvoltage protection typically located between the coupling transformer and the line d

13、river (Ethernet PHY in this document). 3.2 Acronyms AC Alternating Current ANSI American National Standards Institute ATIS Alliance for Telecommunications Industry Solutions Arms Root Mean Squared Amperes BET Building Entrance Terminal CBN Common Bonding Network (also known as an integrated ground p

14、lane) CDE Cable Discharge Event CO Central Office CPE Customer Premises Equipment CRC Cyclic Redundancy Check dB Decibel DUT Device Under Test (aka EUT) DC Direct Current ECL Electronic Current Limiter EMI Electromagnetic Interference EPR Earth Potential Rise EFT Electrical Fast Transient ESD Electr

15、ostatic Discharge Event EUT Equipment Under Test (aka DUT) GbE Gigabit Ethernet GPR Ground Potential Rise HV High Voltage Hz Hertz IEEE Institute of Electric and Electronic Engineers kHz Kilohertz LAN Local Area Network MLT Multi-Level Transition ATIS-0600012.05 10 NID Network Interface Device NRZ N

16、on-return-to-zero OCP Overcurrent protector ONT Optical Network Termination ONU Optical Network Unit OSP Outside Plant PAM Pulse Amplitude Modulation PCB Printed Circuit Board PEC Parallel Earth Conductor PoDL Power over Data Lines PoE Power over Ethernet POTS Plain Old Telephone Service rms Root-Me

17、an-Square RF Radio Frequency RT Remote Terminal SAD Silicon Avalanche Diode SELV Safety Extra Low Voltage (from safety documents IEC/EN/UL 60950-1) SIPO Serial In Parallel Out SNR Signal-to-Noise Ratio SPA Silicon Protection Array STB Set-Top Box STP Shielded Twisted Pair TIA Telecommunications Indu

18、stry Association TNV Telecommunication Network Voltage (from safety documents IEC/EN/UL 60950-1) TSTC Telecommunication Safety Technical (IEEE) Committee TVS Transient Voltage Suppressor UL Underwriters Laboratories UPS Uninterruptable Power Supply UTP Unshielded Twisted Pair VDC Volts of Direct Cur

19、rent Vrms Root Mean Squared Voltage xDSL Digital Subscriber Line ZOI Zone of Influence 4 Description of Ethernet Ethernet was originally designed as an intra-building computer data interface used for interconnect and LAN applications transported by coaxial cabling in a star or ring configuration. IE

20、EE 802.3xx standards cover the various types of Ethernet configurations. There are two types of Ethernet circuits: Digital signals with no dc power. Digital signals with dc power (PoE). ATIS-0600012.05 11 4.1 Standard Ethernet Today, Ethernet generally is transported via Category 5 or higher twisted

21、 pair cable, usually unshielded. Traditionally the common form of Ethernet was 10 or 100BASE-T (which translated into 10 or 100 megabit data rates). More modern versions have GigE and 10GigE capabilities (Gigabit and 10 Gigabit data rates. Base stands for Baseband signaling, T stands for twisted pai

22、r, 10 = 10 Mbps, 100 = 100 Mbps, 1000 = 1000 Mbps, 10G = 10Gbps.) All the standards use either UTP (Unshielded Twisted Pair) or STP (Shielded Twisted Pair) wiring or cabling such as CAT3, CAT5, CAT5e, CAT6, CAT6a, and CAT7. Ethernet connections are typically made with an 8-pin, IEC 60603-7 8P8C modu

23、lar connector (often referred to as an RJ45 type connector). Although CAT6 cable can terminate in an RJ45 modular connector that was designed for lower-grade categories, deploying these connectors will limit the overall system performance below the capability of the CAT 6 cable. There are specific c

24、onnectors designed to complement the CAT6 performance. When CAT6 performance is required, only CAT6 cables and CAT6-developed connectors shall be used. Figure 4.1 below shows the two different connector designs certified by the Telecommunications Industry Association (TIA). When the equipment being

25、connected requires straight through Ethernet cabling, typically both ends of the cable terminate in T568B plugs. If a crossover cable (transmit and receive pairs are crossed) is used, one end of the cable uses a T568B connector, and the other end uses a T568A. In Figure 4.1 below, pins are numbered

26、left to right, 1-8. In both T568A and T568B, for 10/100BASE-T, transmit is on Pair 3, and receive is on Pair 2, while Pairs 1 and 4 are unused for data. For 1000BASE-T (GigE) and 10GigE, all 4 pairs are used and are bi-directional (see ANSI/TIA-568C). Figure 4.1 Ethernet Jacks A summary of 10BASE-T,

27、 100BASE-T, 1000BASE-T and 10GbE is provided below. 10BASE-T Data Rate 10 Mbps Symbol Rate 20Mbaud with 0.5bits/baud ATIS-0600012.05 12 Data Pairs 2 wire pairs out of the 4 wire pair available are used (1 for transmit and 1 for receive) Signaling Differential (i.e., 2 levels) Encoding 4B5B NRZ Manch

28、ester (four bits are scrambled and sent as a 5 bit sequence) Cabling CAT3 or higher up to 100M 100BASE-T (also known as Fast Ethernet) Data Rate 100 Mbps Symbol Rate 125Mbaud with 0.8bits/baud Data Pairs 2 wire pairs out of the 4 wire pair available are used (one wire pair for transmit and one wire

29、pair for receive) Signaling Differential with MLT-3 (Multi Level Transition) Encoding 4B5B NRZ Manchester (four bits are scrambled and sent as a 5 bit sequence) Cabling CAT5 or higher up to 100M 1000BASE-T Data Rate 1000 Mbps Symbol Rate 125Mbaud with 2bits/baud Data Pairs 4 pairs (full duplex) each

30、 pair carries 250 Mbps Signaling Differential PAM-5 (Pulse Amplitude Modulation five-level) signaling Encoding 8B/10B Cabling Preferably CAT5e or higher up to 100M 10GBASE-T (10GbE) Data Rate 10 Gbps Symbol Rate 800M symbols/s Data Pairs 4 pairs (full duplex) Signaling Differential PAM-16 (Pulse Amp

31、litude Modulation sixteen-level) signaling with CRC-8 Encoding DSQ128 (yields 3.5 bits per symbol) Cabling Preferably CAT6 up to 55M or CAT6A/7 up to 100M In general, the signaling scheme becomes more complex as the data rates increase. Figure 4.2 shows the differences in eye diagrams between a 100B

32、ASE-T and 1000BASE-T signal. The ordinate (y-axis) is a normalized value to fit a 1 scale. In the physical world, the maximum Ethernet signals are single-ended 0-5 volts on the PHY side but typically much lower (2 -3.3 volts). ATIS-0600012.05 13 Figure 4.2 Eye Patterns for Ethernet Signals Ethernet

33、was originally used in data centers and the business environment to network computers (LANs). Standard Ethernet technologies have a loop length of approximately 100 meters. But newer proprietary technologies and repeatered Ethernet may extend that range and/or reduce the number of pairs required to

34、attain the same data rates. Residential deployments may include intra-building connections between data and video equipment as well as service to outbuildings, exposing the Ethernet equipment to lightning and power contact. Residential deployments increase possible exposure to overvoltages from AC d

35、istribution wiring in walls compared to a business environment, as well as lightning induced surges in intra-building wiring. In recent years, Ethernet technologies have become major transmission mediums for telecommunications networks to provide backhaul at cell sites, subscriber drops from cabinet

36、 or Optical Network Terminal (ONT), security cameras, Smartgrid devices, IP Phones, Video, and a variety of new and ever evolving telecommunication applications. Ethernet originally was not exposed to significant electrical transient activity, but with new outside plant (OSP) applications and home n

37、etworking, electrical transients are becoming very common on these interfaces, and protection is becoming a requirement. As a result of the potential electrical transients and/or AC voltage exposure, various Standards Development Organizations (SDOs) are developing requirements to address expanding

38、Ethernet circuit applications. Examples of such work include: IEEE 802.3xx All standards in this suite of standards include an isolation test requirement intended to mitigate the effects of longitudinal voltages on the interfaces such as CDEs, GPRs, lightning induced surges, and EFTs. IEC TR-62102 T

39、his document helps determine the level of exposure an Ethernet interface might experience. Its relevance to this standard is summarized and interpreted as follows: IEC TR-62102 establishes a distinction in Ethernet interfaces according to environmental exposure. The low-risk for transients environme

40、nt is designated “Network Environment 0” while the higher risk for transients environment is designated “Network Environment 1”. If an Ethernet signal is within SELV limits and is exposed to transients in a Network Environment 1, then it must be re-categorized as a TNV1 signal. ATIS-0600012.05 14 Ne

41、twork Environment 0 (typically very short-haul intra-building applications) applies only if all of the following conditions exist: o Nearby lightning activity has little or no effect on the interface. o An equipotential bonding system is in place to reduce the possibility of different ground potenti

42、als from lightning GPR at the endpoints. For example, all ground references are bonded via adequately sized conductors to a common grounding electrode system and the structure has only a single AC service entrance. o Potential power fault conditions between interface conductors and power lines are l

43、imited to reduce the possibility of a power fault on the interface. For example, 120 Vrms power fault conditions may be more likely in residential applications but less likely in commercial or business applications with improved electrical code adherence. o Interface cables are not placed in close p

44、roximity to power lines, to reduce or prevent the possibility of induced transients from the power line to the interface. Network Environment 1 exists if one or more of these requirements are not fulfilled. Effective with Issue 6, GR-1089-CORE addresses the criteria for intra-building Ethernet inter

45、faces (Type 2, Type 4, and Type 4a), outside plant exposure Ethernet interfaces (Type 3b and Type 5b), and certain Ethernet applications at cell sites (Type 3a and Type 5a). The following recommendations call for simulated lightning, ESD, and/or EFT, testing for Ethernet interfaces: ITU K.20 Resisti

46、bility of telecommunication equipment installed in a telecommunication center. ITU K.21 Resistibility of telecommunication equipment installed in customer premises. ITU K.45 Resistibility of telecommunication equipment installed in the access and trunk networks. ITU K.44 Resistibility tests for tele

47、communication equipment exposed to overvoltages and overcurrents Basic Recommendation. Various safety standards also have test conditions that apply to Ethernet interfaces: IEC/ 62368-1 Ed. 2.0, Audio/Video, Information Technology Equipment-Safety-Requirements. This safety standard provides testing

48、in clause 6 for interfaces that are determined to have exposure to Environment 1 based on IEC TR-62102. IEC/EN/UL 60950-1 2ndEdition, Information Technology Equipment - Safety - Part 1: General Requirements. At the time of the publication of this ATIS Standard, the IEEE Telecommunication Safety Tech

49、nical Committee (TSTC), in collaboration with other SDOs, is working to clarify and develop the requirements based on IEC TR-62102 and GR-1089-CORE. 4.2 Power over Ethernet (PoE) PoE is a powering technique used over the existing Ethernet wiring link. IEEE standard 802.3af and 802.3at, which have both been replaced with IEEE 802.3-2012, are identified as Type 1 powering and Type 2 powering respectively within the IEEE 802.3 (2012) document. The IEEE 802.3at (Type 2) specification provides the guidelines for PoE+, which is a higher power level than the origina