1、IEEE Std 820-2005(Revision of IEEE Std 820-1984)IEEE Standard Telephone LoopPerformance CharacteristicsI E E E3 Park Avenue New York, NY10016-5997, USA31 January 2006IEEE Power Engineering SocietySponsored by thePower System Communications CommitteeRecognized as anAmerican National Standard (ANSI)IE
2、EE Std 820-2005(R2010)(Revision ofIEEE Std 820-1984)IEEE Standard Telephone Loop Performance CharacteristicsSponsorPower System Communications Committeeof theIEEE Power Engineering SocietyReaffirmed 17 June 2010Approved 22 September 2005IEEE-SA Standards BoardApproved 29 December 2005American Nation
3、al Standards InstituteThe Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2006 by the Institute of Electrical and Electronics Engineers, Inc.All rights reserved. Published 31 January 2006. Printed in the United States of America.IEEE is a r
4、egistered trademark in the U.S. Patent (978) 750-8400. Permission to photocopy portions of any individual standard for educationalclassroom use can also be obtained through the Copyright Clearance Center.Note: Attention is called to the possibility that implementation of this standard may require us
5、e of subject mat-ter covered by patent rights. By publication of this standard, no position is taken with respect to the existence orvalidity of any patent rights in connection therewith. The IEEE shall not be responsible for identifying patentsfor which a license may be required by an IEEE standard
6、 or for conducting inquiries into the legal validity orscope of those patents that are brought to its attention.iv Copyright 2006 IEEE. All rights reserved.IntroductionTelecommunication operating companies generally agree on the requirements that control the performanceof telephone loops, a major fa
7、ctor in the overall performance of the network. This control has been accom-plished through a combination of techniques, which depend on the characteristics of the commonly usedtelephone sets and loop facility design rules. However, no industry performance standards have resulted.With the increasing
8、ly innovative application of emerging technologies and the current trend toward theinterconnect of privately-owned devices with the public network, it is essential that appropriate standards beestablished. This is one such standard. This standard will provide for the characterization of loops atcust
9、omer terminal and switching equipment interfaces and the objective performance evaluation of loopfacilities.This standard was originally prepared in 1984 by the Loop Performance Working Group of the IEEE Trans-mission Systems Committee of the IEEE Communications Society. This Working Group later mer
10、ged withthe Inductive Coordination Electrical Protection (ICEP) subcommittee, then became part of the Communica-tions Society Transaccess Committee. Over time, most of the members of the ICEP SC moved to the Wire-line Subcommittee, under the Power System Communications Committee (PSCC) of the IEEE P
11、ower Engi-neering Society. The Wire-line Subcommittee assumed ownership of this standard during the reaffirmationprocess in 1999.This standard was revised and updated by the Wire-line Subcommittee of the Power System Communica-tions Committee of the IEEE Power Engineering Society.Notice to usersErra
12、taErrata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL forerrata periodically.InterpretationsCurrent interpretations can be accessed at the following URL: http:/s
13、tandards.ieee.org/reading/ieee/interp/index.html.PatentsAttention is called to the possibility that implementation of this standard may require use of subject mattercovered by patent rights. By publication of this standard, no position is taken with respect to the existence orvalidity of any patent
14、rights in connection therewith. The IEEE shall not be responsible for identifyingpatents or patent applications for which a license may be required to implement an IEEE standard or forconducting inquiries into the legal validity or scope of those patents that are brought to its attention.This introd
15、uction is not part of IEEE Std 820-2005, IEEE Standard for Telephone Loop PerformanceCharacteristics.Copyright 2006 IEEE. All rights reserved. vParticipantsThe Wire-line Subcommittee acknowledges the contributions of the Optical and Electrical Access Subcom-mittee (T1E1.3) of the Alliance for Teleco
16、mmunications Industry Solution (ATIS) Network Interface,Power and Protection Committee (NIPP), formerly T1E1, toward the revision of this standard. The Wire-line Subcommittee also acknowledges the individual contributions of Roger Tokarz and TroneBishop.At the time this standard was completed, the P
17、SCC Wire-line Subcommittee (SC-6) had the followingmembership:Percy E. Pool, Chair and Technical EditorLarry S. Young, SecretaryThe following members of the individual balloting committee voted on this standard. Balloters may havevoted for approval, disapproval, or abstention. When the IEEE-SA Stand
18、ards Board approved this standard on 22 September 2005, it had the followingmembership:Steve M. Mills, ChairRichard H. Hulett, Vice ChairDon Wright, Past ChairJudith Gorman, Secretary*Member EmeritusSteve BlumeTimothy ConserErnest M. Duckworth, Jr.Gaetano GranoDavid P. HartmannHarold HeldRichard L.
19、Knight, Sr.Harvey NerhoodBill PetersenMark SimonSteve BlumeAlexander BonnymanStuart BoucheyTerrence BurnsKeith ChowGuru Dutt DhingraGaetano GranoDavid P. HartmannHarold HeldChris HuntleyRichard L. Knight, Sr.Terry KrummreyGregory LuriWilliam McCoyGary MichelMichael NewmanGary L. NissenBill PetersenP
20、ercy E. PoolRoger RayCharles RogersLarry S. YoungMark D. BowmanDennis B. BrophyJoseph BruderRichard CoxBob DavisJulian Forster*Joanna N. GueninMark S. HalpinRaymond HapemanWilliam B. HopfLowell G. JohnsonHerman KochJoseph L. Koepfinger*David J. LawDaleep C. MohlaPaul NikolichT. W. OlsenGlenn Parsons
21、Ronald C. PetersenGary S. RobinsonFrank StoneMalcolm V. ThadenRichard L. TownsendJoe D. WatsonHoward L. Wolfmanvi Copyright 2006 IEEE. All rights reserved.Also included are the following nonvoting IEEE-SA Standards Board liaisons:Satish K. Aggarwal, NRC RepresentativeRichard DeBlasio, DOE Representa
22、tiveAlan H. Cookson, NIST RepresentativeDon MessinaIEEE Standards Project EditorCopyright 2006 IEEE. All rights reserved. viiContents1. Overview 11.1 Scope 11.2 Purpose. 12. References 13. Definitions, acronyms, and abbreviations 23.1 Definitions . 23.2 Acronyms and abbreviations . 34. General infor
23、mation. 44.1 Performance classifications . 44.2 Types of loop facilities 44.3 Interface with the local switching system54.4 Interface at customer premises 54.5 Use of statistical information. 54.6 Measurement procedures . 55. Performance characteristics . 65.1 Loop loss 65.2 Frequency response chara
24、cteristics 95.3 Loop current. 135.4 Loop noise 165.5 Longitudinal balance 22Annex A (informative) Bibliography 24Annex B (informative) Loop current and circuit loss 26Copyright 2006 IEEE. All rights reserved. 1IEEE Standard Telephone Loop Performance Characteristics1. Overview1.1 ScopeThis standard
25、covers the general parameters and characteristics associated with telephone loops from the subscriber signaling and analog voice frequency interface to the local Class 5 switch interface. It includes only those business and residential lines in the North American public switched network where no spe
26、cial performance requirements are involved.This standard provides common denominators for subscriber line performance, independent of facility types, construction processes or equipment, and circuit provisioning methods.1.2 PurposeThe purpose of this standard is to describe quantitatively the perfor
27、mance characteristics of telephone loops and indicate current acceptable performance criteria.2. ReferencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of th
28、e referenced document (including any amendments or corrigenda) applies.ANSI/TIA 470.210-C-2004, TelecommunicationsTelephone Terminal EquipmentResistance and Impedance Performance Requirements for Analog Telephones.1IEEE Std 661, IEEE Standard Method for Determining Objective Loudness Rating of Telep
29、hone Connections.2,31ANSI/TIA publications are available from Global Engineering Documents, 15 Inverness Way East, Englewood, Colorado 80112, USA (http:/ publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331, US
30、A (http:/standards.ieee.org/).3The IEEE standards or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers, Inc.IEEEStd 820-2005 IEEE STANDARD TELEPHONE LOOP2 Copyright 2006 IEEE. All rights reserved.IEEE Std 743, IEEE Standard Equipment Requirem
31、ents and Measuring Techniques for Analog Transmis-sion Parameters for Telecommunications.3. Definitions, acronyms, and abbreviations3.1 DefinitionsFor the purposes of this standard, the following terms and definitions apply. The Authoritative Dictionary of IEEE Standard Terms B144should be reference
32、d for terms not defined in this clause.3.1.1 analog switch: A switch capable of switching analog and digital signals without converting them into a set digital format. Most analog end office switches are two-wire systems that have simple interfaces with the loop.3.1.2 battery feed: The dc supply and
33、 coupling circuit powering the loop.3.1.3 bridged tap: Any portion of a metallic circuit which is not in the direct current (dc) path between the end office (or central office) and the customer network interface. A bridge tap occurs when a branching con-ductor is connected or spliced into a conducto
34、r of the main cable. The bridged tap may be connected at an intermediate location or be an extension of the metallic circuit beyond the customer location. The pair asso-ciated with the bridged tap introduces a frequency-dependent bridging loss in the loop.3.1.4 central office (CO): The building, one
35、 or more switching systems, and related equipment contained therein that provide telephone service.3.1.5 C-Notched filter: A filter used in front of the noise detector in conjunction with the measurement of noise in certain systems. A tone is transmitted in these systems to activate signal-dependent
36、 noise sources, but the tone power should not be included in the measurement. The C-Notched filter has a C-Message weighting transfer function with a sharp notch, which removes this tone from the received signal before its power is measured.3.1.6 customer premises equipment: Any equipment connected
37、by customer premises wiring to the cus-tomer side of the network interface.3.1.7 digital switch: A switch that, internally, performs switching only of digital signals of a set format. It is inherently a four-wire entity, requiring a two-wire to four-wire hybrid at the channel interface when accept-i
38、ng analog signals from two-wire channels.3.1.8 dual-tone multifrequency (DTMF) signaling: Voiceband signaling by simultaneous transmission of two tones, one from a low-frequency group and one from a high-frequency group. Each of these groups con-sists of four voiceband frequency tones, no two of whi
39、ch are harmonically related.3.1.9 end (Class 5) office (EO): A switching system to which customer premises equipment is directly con-nected by loops. The switch connects loops to loops and loops to trunks.3.1.10 four-wire channel: Consists of two unidirectional channels carrying signals in opposite
40、directions.3.1.11 idle circuit: The condition of a transmission channel in the talk state when no signal is present.3.1.12 idle line: The state of a loop when the customer premises equipment connected to it is on-hook.4The numbers in brackets correspond to those of the bibliography in Annex A.IEEEPE
41、RFORMANCE CHARACTERISTICS Std 820-2005Copyright 2006 IEEE. All rights reserved. 33.1.13 loaded loop: A loop into which lumped inductance (loading coil) is introduced at fixed intervals to compensate for the distributed cable capacitance. The addition of loading coils, properly placed, reduces mid-vo
42、iceband loss, flattens the frequency response over most of the voiceband, but creates a sharp cut-off at the high-frequency band edge.3.1.14 longitudinal (common-mode) signal: The longitudinal voltage is half the algebraic sum of the voltages to ground in the two conductors (tip and ring). The longi
43、tudinal current is the algebraic sum of the current in these conductors.3.1.15 loop: The transmission and signaling channel, with or without gain, between the center of the end office switch and the network interface. It also extends dc power to the network interface.3.1.16 metallic (differential) s
44、ignal: The metallic voltage is the algebraic difference between the voltages to ground in the two conductors (tip and ring). The metallic current is half the algebraic difference between the current in these conductors.3.1.17 network interface: The interface between the public switched telephone net
45、work and the customers premises wiring.3.1.18 power influence: The power of a longitudinal signal induced in a telephone circuit by an electromag-netic field emanating from a conductor or conductors of a power system. In common usage, power influence is synonymous with longitudinal noise.3.1.19 subs
46、criber carrier: A system that multiplexes customer signals to achieve pair gain in the loop plant. Usually, it consists of the following:a) An end office terminal (EOT), which interfaces with the EO through analog line appearances, one per each implemented loop. If the carrier is a digital system in
47、tegrated in a digital end office, this ter-minal and its interfaces are replaced by much simpler all-digital equipment that may be integrated into the switching system.b) A remote terminal (RT), which interfaces with the cable pairs to the customers premises through analog interfaces, one per each i
48、mplemented loop.c) A transmission medium between the EOT (or EO in a digital integrated system) and the RT, which provides a control channel for internal EOT/EO-to-RT communication and communication channels for customer traffic. A nonconcentrated system has as many customer channels as implemented
49、loops, with fixed loop-channel assignments. A concentrated system has fewer channels than imple-mented loops, and changes loop-channel assignments to accommodate changing traffic patterns.3.1.20 switch (switching system): A system that establishes communication channels among two or more of its interfaces at customers demand.3.1.21 two-wire channel: A transmission medium that simultaneously carries, without multiplexing, two signals traveling in opposite directions.3.1.22 wire center: A central point from which loop feeder networks extend in
