1、ANSI/TIA/ESA-3700-1999 Approved: August 6, 1999 TIAIEIA STANDARD Telephone Network Transmission Model for Evaluating Analog Modem Performance TIA/EIA-3700 (Upgrade and Revision of TSB37-A) AUGUST 1999 TELECOMMUNICATIONS INDUSTRY ASSOCIATION Eisetronic Indoitries Aliante NOTICE TIAEIA Engineering Sta
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5、bility to any patent owner, nor does it assume any obligation whatever to parties adopting the Standard or Publication. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standa
6、rd to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. (From Standards Proposal Nos. 3459 and 3459-1, formulated under the cognizance of the TIA TR- 30.3 Subcommittee on Data Communications Network Interfaces). Published b
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8、TRIES ALLIANCE STANDARDS and ENGINEERING All rights reserved Printed in U.S.A. STD-EIA TIA/EIA-3700-ENGL 1999 II 3234b00 Ob244b0 40L E TINEIA-3700 Contents TABLES AND FIGURES 111 FOREWORD V INTRODUCTION . VI i SCOPE . 1 2 NORMATIVE REFERENCES . 3 3 DEFINITIONS . 4 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9
9、 3.10 3.1 1 3.12 3.13 3.14 3.1 5 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 3.31 3.32 3.33 3.34 3.35 3.36 3.37 3.38 3.39 adaptive differential pulse coded modulation; ADPCM assigned network distribution attenuation distortion; AD Bell operating company connection type
10、 digital loop camer system; DLC echo envelope delay distortion; EDD far-end echo frequency offset; FO impairment combination; IC intercontinental connection intermodulation distortion: IMD intracontinental connection Intra-LATA likelihood of occurance; LOO listener echo loaded loop Local Access and
11、Transport Area; LATA local exchange carrier; LEC near-end echo network section non-loaded loop phase jittei phase roll of the far-end (talker) echo private branch exchange; PBX puise coded modulation; PCM PCM Link regional Bell operating company; RBOC robbed bit signaling; RBS robbed bit signaling;
12、link, RBS link round trip delay; RTD talker echo tandem connection test channel test loop combination; TLC tone to noise ratio; TNR transhybrid loss; THL trunk 4 DESCRIPTION OF MODEL . 8 4.1 OVERVIEW . 8 4.2 TABLE STRUCTURE AND IC NUMBERING 8 4.3 TEST CHANNEL NUMBERING . 9 4.4 ECHO CHARACTERISTICS 9
13、 4.5 ECHO CONTROL REQUIREMENTS 9 4.6 ADDED NOISE . 9 i TINEIA-3700 4.7 ROUND TRIP DELAY CRITERIA . 10 4.8 MODEM IMPEDANCE REQUIREMENTS . 10 4.9 DIGITAL IMPAIRMENT REQUIREMENTS 10 4.10 NETWORK MODEL COVERAGE (NMC) . li 5 IMPAIRMENT LEVEL SETUP 13 5.1 TRANSMITTED SIGNAL POWER MEASUREME NT 13 5.2 INTER
14、MODULATION DISTORTION CALIBRATION 13 5.3 TONE TO NOISE RATIO LEVEL . 13 5.4 TRANS-HYBRID LOSS MEASUREMENT . 13 ANNEX A (NORMATIVE) ATTENUATION AND ENVELOPE DELAY DISTORTION CHARACTERISTICS28 ANNEX B (INFORMATIVE) RARE NORTH AMERICAN CONTINENTAL NETWORK MODEL 47 ANNEX C (INFORMATIVE) INTERCONTINENTAL
15、 NETWORK MODEL . 49 ANNEX D (INFORMATIVE) BASIS FOR NETWORK MODELS 51 0 .i Introduction . 5 0.2 Legend . 51 0.3 Description of Connections Types . 53 Table 2 -Inter-LATA Model Connection Types 53 D.3.1.1 Impairment Combination BI 53 D.3.1.2 Impairment Combination 82 53 D.3.1.3 Impairment Combination
16、 B3 53 D.3.1.4 Impairment Combination 84 54 Table 3 . Intra-LATA Connection Types 55 D.3.2.1 impairment Combination 85 55 D.3.2.2 Impairment Combination B6 56 D.3.2.3 Impairment Combination B7 57 Table BI - Rare North American Test Channels . 57 D.3.3.1 Impairment Combination B8 57 D.3.3.2 Impairmen
17、t Combination B9 58 D.3.3.3 Impairment Combination BIO 58 D.3.3.4 Impairment Combination BI1 58 D.3.3.5 impairment Combination 812 58 D.3.3.6 Impairment Combination 813, 814, BI5 . 59 Table CI . Intercontinental Network Test Channels 59 D.3.4.1 Impairment Combination B16, B17, BI8 . 59 D.3.4.2 Impai
18、rment Combination BI9 and 820 60 D.3.4.3 impairment Combination B21 and 822 60 ANNEX E (INFORMATIVE) INFORMATIVE REFERENCES . 62 D.3.1 D.3.2 D.3.3 D.3.4 STDmEIA TIAIEIA-3700-ENGL 1997 I 3234b00 Ob24462 284 TINEIA-3700 Tables and Figures Figure 1-Table Structure and IC Numbering . 8 Figure 2-Network
19、Section(NS) Test Equipment Configuration . 14 Figure %Single Network Section Test Equipment Configuration 14 Figure Impairment combinations have been added to form intra-LATA connection model; A fourth impairment combination level, “d“ which includes impairment combinations compatible with the new h
20、igher V.34 rates, has been added; and Impairment Combinations with Digital Loop Carriers using central office terminals, (2-wire switch interfaces) have been added. This Standard defines a network model for performance testing of modems and similar devices intended for the transmission of non-voice
21、signals over the public switched telephone network. TINEIA 496A specifies the network interface characteristics relevant to connection establishment and disconnection. This Standard is intended to be used with TINEIA 3800 (Currently under study as PN3509), “Test Procedures for Evaluation of 2-Wire D
22、uplex Modems.“ There are five annexes in this Standard. Annex A is normative and is considered part of this Standard. Annexes B through E are informative and are not considered part of this Standard. s IO 1. 15 disappeared from the network; 2. 3. 4. 5. 20 25 V STD-EIA TIA/EIA-3700-ENGL 2999 W 3234b0
23、0 Ob24465 793 TINEIA-3700 I nt rod uct i on TIA Subcommittee TR-30.3 continues its work refining and updating information concerning modem transmission performance over the public switched telephone network (PSTN). Since December 1991 the subcommittee has concentrated on deriving a model of the PSTN
24、 covering characteristics that determine modem transmission performance, and updating this model to keep pace with changes in the network and modem technology. The Subcommittee realizes that manufacturers of modems, users of moderns, and network providers are interested in a specification that accur
25、ately models the network characteristics that determine modem performance. The Subcommittee is also aware that evaluators desire a simple test that properly measures the performance of modems from various manufacturers. Therefore, the objective is to define a model that is representative of todays t
26、elephone network, can be simulated at reasonable cost, and facilitates short modem evaluation times. Evolution of Modem Test Standards In prior standards, such as section five of ANSI/EIA/TIA 496-A and the entirety of TSB-37, several sets of characterizations were defined that required the intensity
27、 of a single impairment, such as signal-to-noise ratio or impulse noise, to be varied and modem performance plotted in swxlled “waterfall curves.“ The resulting curves provided a basis for evaluating the relative performance of modems against individual impairments - particularly noise, which was th
28、e dominant impairment in most connections. However, the correlation between these waterfall curves and actual PSTN conditions was not addressed by those standards. With the beginning of the V.34 standard development, the Subcommittee elected to abandon the earlier model which contains ranges for the
29、 levels of impairments, replacing it with a model that specifies representative values of impairment combinations and their likelihood of occurrence. Each impairment combination represents all channels with similar impairment values and the associated likelihood of occurrence is for the set of simil
30、ar channels, not the one impairment combination in the channel. This new model features impairment combinations for a range of interoffice connection types, each representing a combination of facilities that can be encountered in the network, e.g., digital end offices connected with four-wire digita
31、l transport. For each such impairment combination, sub-combinations are defined with the impairment (e.g. intermodulation distortion) levels varying from mild to severe, ail with assigned likelihood of occurrence of being encountered in the network. These impairment combinations are used with a set
32、of subscriber loops that approximate the loop environment. Since the first publication of TSB-37A in 1994, the network has continued to evolve toward an all-digital network. However, the use of Digital Loop Carrier systems has grown dramatically, with many of these carrier systems connected to local
33、 offices via 2-wire analog line circuits on local switches. This increases the number of connections that will have multiple digital links with additional 4-wire to 2-wire conversions, resulting in multiple sources of echoes. The trans-hybrid loss (THL) values listed in TSB-37A are high. With the mo
34、re representative lower THLs, the talker and listener echo conditions in local or short intra-LATA connections (which have very low 4- wire insertion loss) become important. To properly reflect these conditions, an intra-LATA network model has been added. The inclusion of this model is especially ap
35、propriate considering that the use of modems in intra-LATA connections has increased because of the growth of the intra-LATA Intemet Service Provider (ISP) market. With the inclusion of the intra-LATA model in this standard, the scope of the model contained in TSB-37A has been changed to inter-LATA
36、and renamed accordingly. 45 Architecture of the Network Model vi STD-EIA TIA/EIA-3700-ENGL 1999 3234600 0624466 92T I a 99 I TINEIA-3700 99 In TSB-37A, the ICs for each connection were defined for three levels of severity. In this Standard, the impairment combinations for each connection are associa
37、ted with four levels of severity, indicated by the letters “a“, “b“, “c“, and “d“. Satisfactory performance over an IC of a particular level indicates such performance over an associated percentage of network connections of the type involved. The following table shows the relationships of the letter
38、 designators to the percentage of connections of the same type that have equal or less overall impairment levels, and should produce equal or better modem performance. Network Impairment Percentiles Level Inter-LATA Network Intra-LATA Network 5 b C d 95 95 85 85 40 50 The “d“ level of severity was a
39、dded to include impairment combinations compatible with the new higher V.34 rates. The topology associated with each trunk configuration is described in Annex D. The impairment combinations do not characterize the contribution of local metallic subscriber loops to the models. To provide a complete t
40、est channel (end-to-end connection), subscriber loops are added at each end of the link. This standard defines seven standard pairs of subscriber loops (test loop combinations, or TLCs) which complete the model for each test channel. The seven standard TLCs also have likelihood of occurrence associa
41、ted with them. The likelihood of occurrence for each test channel is the product of the likelihood of occurrence of the IC and the likelihood of occurrence of the TLC. 15 STD-EIA TIA/EIA-3700-ENGL 1997 3234b00 Ob244b7 866 II TINEIA-3700 Telephone Network Transmission Model For Evaluating Analog Mode
42、m Performance 1. SCOPE 5 10 15 40 This Standard defines a model of the characteristics of the Public Switched Telephone Network (PSTN) in the continental United States of America to be used to measure modem transmission performance. The model is intended to be a basis for performance testing of 2-wi
43、re modems for use on the PSTN. The model includes specifications for the configuration and setup of suitable simulator equipment to be used in evaluations and comparisons of such modems. Warning The network models described in Tables 2 and 3 do not model all possible connections that can be encounte
44、red between two telephone subscribers in the United States. Models of some rare connections that may be encountered in the continental United States and of intercontinental connections are described in the Annexes. In addition, the distributions assigned in Table 3 are mainly based on network statis
45、tics with the ratio of inter-LATA to intra-LATA connections being an estimate. The PSTN is modeled by two network models and a single subscriber loop model. The first network model represents the relevant characteristics of inter-exchange telephone connections over the inter- LATA network and is bas
46、ed on network statistics (see limitation 12 below). The second network model represents the relevant characteristics of intra-LATA (both intra- and inter-office) telephone connections and are based on assigned network distributions (see limitation 14 below). The subscriber loop model is used with bo
47、th network models to describe the relevant characteristics of end-t-nd connections. The ICs for the Inter-LATA model take into account the presence of large private branch exchange (PBX) systems commonly found in business environments. It is believed that the majority of PBX systems are taken into a
48、ccount in the network and subscriber loop models. Limitations on this model: i. 2. 3. 4. 5. 6. This model is valid only for two-wire analog PSTN end to end connections. This model does not include any network characterizations for either two-wire or four-wire leased-line circuits, or for digitally c
49、onnected modems. This model does not include dynamic impairments, such as impulse noise or digital synchronization slips. This model does not include very low-probability connection scenarios. Very low-probability scenarios are defined as scenarios with a likelihood of occurrence in the network of a small fraction of a percent. Some of these scenarios are specified in Annex B. Test loop combinations specified are intended to be representative of the subscriber loop population with respect to insertion loss, attenuation di
