1、 ATIS-0600012 ATIS Standard on - Electrical Protection Considerations for Broadband 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 pressin
2、g 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, billing support,
3、 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 American National S
4、tandards 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-American Telec
5、ommunication Commission (CITEL). For more information, visit www.atis.org. Notice of Disclaimer it will conduct current once its breakdown voltage has been exceeded (it is a variable resistor model). 3.1.12 Positive Temperature Coefficient (PTC) thermistor: A current limiting device, the resistance
6、of which increases as a function of the temperature caused by the heating effect of the current and PTC resistance. 3.1.13 Thyristor: A semi-conductor device that conducts current by switching into a short-circuit once its breakdown voltage has been exceeded. The thyristor is reset back into its hig
7、h-impedance state once the current falls below its holding current value. 3.2 Acronyms 350 mA heat coils have 4 resistance. An alternative to heat coils is the PTC thermistor. From a current-limiting standpoint, the resistance of the PTC increases as excessive current heat the PTC, thus limiting the
8、 fault current. From a transmission standpoint, the PTC has minimal inductance and a resistance typically between 1 and 20 , thus do not significantly degrade the high frequency components of the broadband signal. The third type of current limiting component is the ECL. The ECL is a solid-state comp
9、onent that switches very quickly from a low resistance state (typically 6 to 15 ) to an essentially open circuit when the designed current threshold is exceeded, thus opening the signal/surge path. When used, they are located on the equipment side of an overvoltage protection device and keep the cir
10、cuit open until the overvoltage protection device operates. When the overvoltage protection device operates, it shorts this surge current to ground. ECLs have a minimal amount of ATIS-0600012 7 attenuation that is very uniform across all broadband spectrums. Note that a 6 device in each conductor re
11、sults in a total loop resistance increase of 12 that must be considered. Table 5.1: Primary Protector Voltage and Current Protection Comparisons Protection Element Surge Firing, Current Limiting Threshold Access transmission system on metallic access cables; Symmetrical single pair high bit rate Dig
12、ital Subscriber Line (SDSL); Part 2: Transceiver requirements.1013 European Standard 61000-4-5, Electromagnetic Compatibility Part 4-5: Testing and measurement techniques S.1114 ITU-T Recommendation G.991.1, High bit rate Digital Subscriber Line (HDSL).1215 ITU-T Recommendation G.991.2, Single-pair
13、high-speed digital subscriber line (SHDSL) transceivers.1216 ITU-T Recommendation G.992.1, Asymmetric digital subscriber line (ADSL) transceivers.1217 ITU-T Recommendation G.992.2, Splitterless asymmetric digital subscriber line (ADSL) transceivers.1218 ITU-T Recommendation G.992.3, Asymmetric digit
14、al subscriber line transceivers 2 (ADSL2).1219 ITU-T Recommendation G.992.4, Splitterless asymmetric digital subscriber line transceivers 2 (splitterless ADSL2).1220 ITU-T Recommendation G.993.1, Very high speed digital subscriber line transceivers (VDSL).1221 ITU-T Recommendation G.993.2, Very high
15、 speed digital subscriber line transceivers 2 (VDSL2).1222 ITU-T Recommendation G.992.5, Asymmetric digital subscriber line (ADSL) transceivers - Extended bandwidth ADSL2 (ADSL2+).11 7This document is available from the Institute of Electrical and Electronics Engineers (IEEE). 8This document is avai
16、lable from the National Fire Protection Association (NFPA). 9This document is available from the Alliance for Telecommunications Industry Solutions, 1200 G Street N.W., Suite 500, Washington, DC 20005. 10This document is available from the European Telecommunications Standards Institute (ETSI). 11This document is available from the International Electrotechnical Commission. 12This document is available from the International Telecommunications Union.
