1、i ATIS-0600413.2009 (Revision of T1.413-2004) American National Standard for Telecommunications NETWORK TO CUSTOMER INSTALLATION INTERFACES - ASYMMETRIC DIGITAL SUBSCRIBER LINE (ADSL) METALLIC INTERFACE Alliance for Telecommunications Industry Solutions Approved March 23, 2009 American National Stan
2、dards Institute, Inc. Abstract This standard describes the interface between the telecommunications network and the customer installation in terms of their interaction and electrical characteristics. The requirements of this standard apply to a single asymmetric digital subscriber line (ADSL). ATIS-
3、0600413.2009 ii FOREWORD The information contained in this Foreword is not part of this American National Standard (ANS) and has not been processed in accordance with ANSIs requirements for an ANS. As such, this Foreword may contain material that has not been subjected to public review or a consensu
4、s process. In addition, it does not contain requirements necessary for conformance to the Standard. The Alliance for Telecommunication Industry Solutions (ATIS) serves the public through improved understanding between providers, customers, and manufacturers. The Copper/Optical Access, Synchronizatio
5、n and Transport (COAST) Committee - formerly the Optical Transport and Synchronization Committee (OPTXS) - engages industry expertise to develop and recommend standards and technical reports for home, access and transport network and synchronization technologies over copper and optical mediums. COAS
6、T is committed to proactive engagement with national, regional and international standards development organizations and forums that share its scope of work. The technical requirements, measurement techniques, metrics, and operational practices documented in COASTs work products encompass copper and
7、 optical network interfaces and transceiver functionality required for access to, and transport through, telecommunications networks. ANSI guidelines specify two categories of requirements: mandatory and recommendation. The mandatory requirements are designated by the word shall and recommendations
8、by the word should. Where both a mandatory requirement and a recommendation are specified for the same criterion, the recommendation represents a goal currently identifiable as having distinct compatibility or performance advantages. Suggestions for improvement of this document are welcome. They sho
9、uld be sent to the Alliance for Telecommunications Industry Solutions, COAST, 1200 G Street NW, Suite 500, Washington, DC 20005. The Network Access Interfaces (NAI) Subcommittee was responsible for the development of this Standard when it was part of the Network Interface, Power, and Protection Comm
10、ittee (NIPP). At the time of consensus on this document, NIPP had the following roster: E. Eckert, NIPP Chair (Ikanos) K. Sievert, NIPP Vice-Chair (Verizon) C. Underkoffler, ATIS Chief Editor K. Sievert, Technical Editor (Verizon) Organization Represented Name of Representative Actelis Networks Inc.
11、 Ioannis Kanellakopoulos, PhD ADTRAN Inc. Arlynn Wilson Richard Goodson (Alt.) Aktino, Inc. Ray Nagele Michail Tsatsanis (Alt.) Alcatel - Lucent Ken Biholar Tim Pantalis (Alt) American Insulated Wire Corp Suren Shah Lowell Lisker (Alt) ASSIA Inc. Peter Silverman Wonjong Rhee (Alt.) AT in the other d
12、irection, only low-speed bearer channels are provided. The transmission system is designed to operate on two-wire twisted metallic cable pairs with mixed gauges. The standard is based on the use of cables without loading coils, but bridged taps are acceptable in all but a few unusual situations. Spe
13、cifically, this standard: Describes the transmission technique used to support the simultaneous transport of voiceband services and both simplex and duplex digital channels on a single twisted-pair. Defines the combined options and ranges of the digital simplex and full-duplex channels provided. Def
14、ines the line code and the spectral composition of the signals transmitted by both ATU-C and ATU-R. Specifies the transmit signals at both the ATU-C and ATU-R. Describes the electrical and mechanical specifications of the network interface. Describes the organization of transmitted and received data
15、 into frames. Defines the functions of the operations channel. Defines the ATU-R to service module(s) interface functions. Defines the Transmission Convergence Sub-layer for ATM transport. 1.2 Purpose This interface standard defines the minimal set of requirements to provide satisfactory simultaneou
16、s transmission between the network and the customer interface of POTS and a variety of high-speed simplex and low-speed duplex channels. The standard permits network providers an expanded use of existing copper facilities. All Layer 1 aspects required to ensure compatibility ATIS-0600413.2009 2 betw
17、een equipment in the network and equipment at a remote location are specified. Equipment may be implemented with additional functions and procedures. 2 REFERENCED STANDARDS 2.1 Normative References The following standards contain provisions that, through reference in this text, constitute provisions
18、 of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the stan
19、dards indicated below. ATIS-0300231.2003 (R2007), Digital Hierarchy - Layer 1 In-service Digital Transmission Performance Monitoring.1ATIS-0600601.1999 (R2009), Integrated Services Digital Network (ISDN) Basic Access Interface for Use on Metallic Loops for Application on the Network Side of the NT (
20、Layer 1 Specification).1ANSI/IEEE 455-1985 (R1993), Test Procedure for Measuring Longitudinal Balance of Telephone Equipment Operating in the Voiceband, 1985 or later.2ANSI/IEEE 743-1995, Equipment Requirements and Measurement Techniques for Analog Transmission Parameters for Telecommunications.2ITU
21、-T Recommendation I.432.1, B-ISDN User-Network Interface - Physical Layer Specification: General Characteristics, August 1996.32.2 Informative References The following standards are for informative purposes only. T1.413-1995, Network and Customer Installation Interfaces - Asymmetrical Digital Subscr
22、iber Line (ADSL) Metallic Interfaec referred to as “Issue 1” within this standard.4T1.413-2004, Network and Customer Installation Interfaces - Asymmetrical Digital Subscriber Line (ADSL) Metallic Interfaec referred to as “Issue 2” within this standard.4NOTE The current standard, this document, is re
23、ferred to as “Issue 3”. DEFINITIONS, ABBREVIATIONS, ACRONYMS, that is, the difference between total data rate and net data rate (5.3). 3.1.2 aggregate data rate: Data rate transmitted by an ADSL system in any one direction; it includes both net data rate and overhead used by the system for eoc, aoc,
24、 crc check bytes, fixed indicator bits for OAM, synchronization control bytes and capacity for bearer channel synchronization control (i.e., KF + KItimes 32 kbit/s); it does not include Reed-Solomon FEC redundancy (6.4.1.2). 3.1.3 aggregate transmit power: The integrated transmit power over a partic
25、ular frequency interval (in mWatts or dBm). 3.1.4 bearer channel: A user data stream of a specified data rate that is transported transparently by an ADSL system in ASx or LSx, and carries a bearer service. 3.1.5 bearer service: The transport of data at a certain rate without regard to its content,
26、structure, or protocol. 3.1.6 bridged taps: Sections of unterminated twisted-pair cables connected in parallel across the cable under consideration. 3.1.7 category 1: Basic category of transceivers with no performance-enhancing options, which meet a basic set of performance requirements (11.1). 3.1.
27、8 category 2: Category of transceivers with performance-enhancing options, which meet an expanded set of performance requirements (11.1). 3.1.9 channelization: Allocation of the net data rate to bearer channels. 3.1.10 Crest factor: Peak-to-rms voltage ratio. 3.1.11 cyclic prefix: Periodic extention
28、 of the time domain representation of a symbol, inserted at the transmitter, to avoid symbol distortion at the receiver due to the line impulse response. 3.1.12 data symbol rate: The average symbol rate (after allowing for the overhead of the sync symbol) at which symbols carrying data are transmitt
29、ed (i.e., 4000 symbols/sec). 3.1.13 downstream: ATU-C to ATU-R direction. 3.1.14 dual latency: Simultaneous transport of multiple bearer channels through the fast and the interleaved path; that is, BF0 and BI 0. An ADSL system may operate in dual latency mode in one direction only or in both. 3.1.15
30、 indicator bits: Bits used for OAM purposes; embedded in the sync bytes (6.4.1.1). 3.1.16 line rate: Total data rate plus trellis coding overhead (i.e., bitimes 4 kbit/s). 3.1.17 loading coils: Inductors placed in series with the cable at regular intervals in order to improve the voiceband response;
31、 removed for DSL use. 3.1.18 net data rate: Data rate that is available for user data in any one direction; for the downstream direction, this is the sum of the simplex and duplex bearer channel data rates (i.e., BF + BItimes 32 kbit/s), with addition of 16 kbit/s if a 16 kbit/s “C”-channel is used.
32、 3.1.19 showtime: The state of either ATU-C or ATU-R, reached after all initialization and training is completed, in which data is transmitted (see clause 9 and Annex A). 3.1.20 single latency: Simultaneous transport of one or more bearer channels through either the fast or the interleaved path; tha
33、t is, BF = 0 or BI = 0. An ADSL system may operate in single latency mode in one direction only or in both. ATIS-0600413.2009 4 3.1.21 splitter: Filters that separate the high-frequency signals (ADSL) from the voiceband signals; frequently called POTS splitters even though the voiceband signals may
34、comprise more than POTS (4.1 and 12.2). 3.1.22 sub-carrier: One of the complex inputs Zito the IDFT (6.11.2). 3.1.23 symbol: The collection of complex values Ziforming the frequency domain input for the IDFT or, alternatively, the collection of real values xnforming the time domain output of the IDF
35、T (6.11.2 and 7.11.2). Symbols may be sent with or without cyclic prefix (6.12). 3.1.24 symbol rate: The rate at which all symbols, including the sync symbol, are transmitted - i.e., (69/68) 4000 = 4058.8 symbols/sec; contrasted with the data symbol rate. 3.1.25 total data rate: Aggregate data rate
36、(q.v.) plus Reed-Solomon FEC overhead (i.e., NF + NItimes 32 kbit/s). 3.1.26 upstream: ATU-R to ATU-C direction. 3.1.27 voiceband: The 0- to 4-kHz frequency band. 3.1.28 voiceband services: POTS and all data services that use the 0- to 4-kHz band or some part of it. 3.2 Abbreviations, Acronyms, one
37、of the services using the voiceband; sometimes used as a descriptor for all voiceband services PRD Pseudo-Random Downstream (9.4.6) PRU Pseudo-Random Upstream (9.5.2) PSD Power Spectral Density (6.13, 7.13) PSTN Public Switched Telephone Network (4.1) PRBS Pseudo-Random Bit Sequence QAM Quadrature A
38、mplitude Modulation (9.6, 9.7) RFnumber of downstream (or upstream) FEC redundancy bytes per RS codeword for the fast buffer (6.4.1.2.1) RInumber of downstream (or upstream) FEC redundancy bytes per codeword for the interleaved buffer (6.4.1.2.2) RA Rate Adaptation rdi remote defect indication (8.2)
39、 RRD Revised Resistance Design RFI Remote Failure Indication (8.2) or Radio Frequency Interferer (11.3.1.3) rms root-mean-square RT Remote Terminal sc0-7 synchronization control bit(s) (6.4.1.1) sef severely errored frame defect (8.2) SM Service Module (4.1) SONET Synchronous Optical NETwork (4.1) S
40、RL Singing Return Loss (13.2) STM Synchronous Transfer Mode (5.1) TPS Transport Protocol Specific (6.1, 6.2) TC Transmission Convergence (layer) (6.1, 6.2) T-R interface(s) between ATU-R and switching layer (ATM or STM) T/S interface(s) between NT and CI or home network (4.1) U-C loop interface - ce
41、ntral office end (4.1) U-R loop interface - remote terminal end (4.1) V-C logical interface between ATU-C and a digital network element such as one or more switching systems (4.1) XT Crosstalk 4-QAM 4-point QAM (i.e., two bits per symbol) (9.6, 9.7) exclusive-or; modulo-2 addition 4 REFERENCE MODELS
42、 4.1 System Reference Model The system reference model shown in Figure 1 illustrates the functional blocks required to provide ADSL service. ATIS-0600413.2009 7 U-RU-CSplitterRSplitterCNTloop POTSPSTNNarrowbandNetworkPHYV-CPHYCustomerPremiseNetworkATU-RATU-CT-RSMSMT/SHPFLPFU-C2HPFLPFU-R2Signal lines
43、InterfacesBroadbandNetworkTelephone setor Voice-bandmodemFigure 1 - ADSL system reference model NOTES: 1. The U-C and U-R interfaces are fully defined in this specification. The V-C and T-R interfaces are defined only in terms of logical functions, not physical. The T/S interface is not defined here
44、. 2. The V-C interface may consist of interface(s) to one or more (STM or ATM) switching systems. 3. Implementation of the V-C and T-R interfaces is optional when interfacing elements are integrated into a common element. 4. One or other of the high-pass filters, which are part of the splitters, may
45、 be integrated into the ATU; if so, then the U-C 2 and U-R 2 interfaces become the same as the U-C and U-R interfaces, respectively. 5. A digital carrier facility (e.g., SONET extension) may be interposed at the V-C interface. 6. Due to the asymmetry of the signals on the line, the transmitted signa
46、ls shall be distinctly specified at the U-R and U-C reference points. 7. The nature of the CI distribution and customer premise network (e.g., bus or star, type of media) is for further study. 8. More than one type of T-R interface may be defined, and more than one type of T/S interface may be provi
47、ded from an ADSL NT (e.g., NT1 or NT2 types of functionalities). 9. A future issue of this standard may deal with CI distribution and home network requirements. 10. A more detailed definition of the splitters is given in Annex E. ATM and STM are application options. ATU-C and ATU-R may be configured
48、 for either STM bit sync transport or ATM cell transport. Hybrid configurations (i.e., some applications run over ATM, some do not, simultaneously) are outside the scope of this standard. If the U-C interface is STM bit sync based (i.e., no ATM cells on U-C interface), the ATU-C is configured for ST
49、M transport and shall comply with 4.2.1, 5.1, and 6.1. If the U-C interface is ATM cell based (i.e., only ATM cells on U-C interface), the ATU-C is configured for ATM transport and shall comply with 4.2.2, 5.2, and 6.2. If the U-R interface is STM bit sync based (i.e., no ATM cells on U-R interface), the ATU-R is configured for STM transport and shall comply with 4.3.1, 5.1, and 7.1. If the U-R interface is ATM cell based (i.e., only ATM cells on U-R interface), the ATU-R is configured for ATM transport and shall comply wi
