1、_ STD*ITU-T RECMN I-572-ENGL 2000 m 48b259L Ob88736 4T2 m INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STAN DARD IZATION SECT0 R OF ITU SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Internetwork interfaces 1.572 (03/2000) VSAT interconnection with the PSTN ITU-T Recommendation 1.572
2、 (Formerly CCITT Recommendation) STD-ITU-T RECmN 1.572-ENGL 2OOO 4862573 0688737 337 = ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE Terminology Description of ISDNs General modelling methods Telecommunication network and service attributes General description
3、of asynchronous transfer mode Scope General aspects of services in ISDN Common aspects of services in the ISDN Bearer services supported by an ISDN Teleservices supported by an ISDN Supplementary services in ISDN Network functional principles Reference models Numbering, addressing and routing Connec
4、tion types Performance objectives Protocol layer requirements General network requirements and functions Application of I-series Recommendations to ISDN user-network interfaces Layer 1 Recommendations Layer 2 Recommendations Layer 3 Recommendations Multiplexing, rate adaption and support of existing
5、 interfaces SERVICE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS ISDN USER-NETWORK INTERFACES I. 1 1 0-1.1 1 9 I. 120-1.129 I. 1 30-1.139 I. 1 40-1.149 I. 150-1. 199 1.200-1.209 1.2 1 0-1.2 19 1.220-1.229 1.230-1.239 1.240-1.249 I. 25 (2-1.299 1.310-1.319 1.320-1.329 1.330-1.33 9 1.340-1.349 1
6、.35 0-1. 359 I. 3 60-1.369 1.370-1.399 1.420-1.429 1.430-1.439 1.440-1.449 1.4.50-1.459 1.460-1.469 Aspects of ISDN affecting terminal requirements 1.470-1.499 MAINTENANCE PlUNCIPLES 1.600-1.699 B-ISDN EQUIPMENT ASPECTS ATM equipment 1.730-1.739 Transport functions 1.740-1.749 Management of ATM equi
7、pment 1.750-1.799 For further details. please refer to the list of ITU-TRecommendations. STDaITU-T RECMN 1-572-ENGL 2000 4Bb257L 0688738 275 0 ITU-T Recommendation 1.572 VSAT interconnection with the PSTN Summary This ITU-T Recommendation describes the functional technical requirements for the incor
8、poration of VSATs into the Access portion of national telephone networks, both public and private. Scenarios illustrate some but not all of the ways that VSATs might be deployed in this portion of the network. A pre-existing analogue network has been assumed for the discussion of transmission planni
9、ng with digital technology included where significant. The annexes contain details of several national connection requirements and when considered as a whole provide a good overview of connection requirements for all national telephone networks. Additional annexes may be added in future to cover oth
10、er countries. Source ITU-T Recommendation 1.572 was prepared by ITU-T Study Group 13 (1997-2000) and approved under the WTSC Resolution 1 procedure on 10 March 2000. STD-ITU-T RECMN 1.572-ENGL ZOO0 4862593 Ob88739 30% FOREWORD The International Telecommunication Union (ITU) is the United Nations spe
11、cialized agency in the field of telecommunications. The lTU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on
12、 a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topic s. The approval of ITU-T Recommendations is covered by the procedure laid
13、 down in WTSC Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunicat
14、ion administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity o
15、r applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required t
16、o implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
17、 means, electronic or mechanical, including photocopying and microfilm, without permission in writing fiom the ITU. 1 2 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 8 8.1 8.2 8.3 8.4 8.5 9 10 11 11.1 11.2 12 12.1 12.2 Page Introduction Scope References Terms and definitions . Abbreviations . Access Network Scenari
18、os . Scenario 1 . A few single terminals connected to a National network via a VSAT network . Scenario 2 . Several end users attached to the Remote Interface Unit Scenario 3 . Geographically distributed multiple user outstations Scenario 4 . Extension of previous scenarios to include accesses to mul
19、tiple main networks . Scenario 5 . Connection via a Remote PBX Scenario 6 . Inclusion of a Local PBX 7.6.1 Considerations relating to isolated digital transmission components . Scenario 7 . PBXs at both ends . General issues . Transmission planning Echoes . Digital encoding of voiceband signals . Re
20、mote station technology . Multiple public networks Interconnection policy Interconnection to National Telephone networks at the lowest level of the national transit network. the Local exchange . Local Exchange analogue ports Local Exchange basic parameters . Digital ports Transmission planning Intro
21、duction of VSATs into the Access network . Transmission impairments 12.2.2 Quantizing noise 12.2.1 General noise and interference 1 5 6 9 10 11 11 12 13 13 13 13 13 13 13 14 16 17 17 17 18 22 22 23 12.3 12.4 12.5 12.6 12.7 12.8 12.9 13 14 15 15.1 16 17 18 19 19.1 19.2 19.3 19.4 19.5 Transmission lev
22、els 12.3.1 The National Transmission Plan . 12.3.2 Selection of Loss in a VSAT system . 12.3.3 Signal-to-Quantization Distortion ratio . Attenuation frequency distortion Group delay frequency distortion . Crosstalk . 12.6.1 Crosstalk parameters . Stability . Echo considerations Clipping 12.9.1 Front
23、-end clipping . 12.9.2 Temporal clipping . “Permission to Connect“ requirements for private networks . 12.9.3 Power level clipping Remote terminal penetration enhancement techniques Management . Operations and maintenance . Availability . Commissioning . Numbering issues . The Network Operators pers
24、pective Billing . Routine testing Payphone support . Call Set-up times . Special services support . Page 23 23 25 25 26 26 26 26 28 30 30 30 30 30 31 31 31 31 31 31 32 32 32 32 32 32 32 Annex A . Organization of annexes 32 33 Annex B . The analogue 2-wire port facing the exchange within Europe B . 1
25、 Introduction and methodology 33 Identification of the states of the Terminal Equipment (TE) 33 B.2.1 TE allowed basic states . 33 B.3 d.c. characteristics 35 B.3.1 Contents . 35 B.2 B.4 B.5 B.6 B.7 B.8 B.3.2 Central Battery Exchange Systems . B.3.3 Insulation resistance B.3.4 d.c. conditions in the
26、 loop state . B.3.5 Overload susceptibility . Voiceband signal transmission characteristics . B.4.1 Input impedance ofthe TE B.4.2 Multi-parameter Balance requirements . B.4.3 B.4.4 Maximum signal levels at the TE B.4.5 Noise B.4.6 B.4.7 The calling function B.5.1 B.5.2 Dialling with MFPB (DTMF) . B
27、.5.3 Automatic calling precautions . Voiceband signalfiequency characteristics of the TE Immunity to out-of-band signalling National limits on the level of signals sent to line Detection of the dialling reception state of the exchange . The answering function B.6.1 Ringing detectors . B.6.2 Automati
28、c answering function B.6.3 Loss of signal B.6.4 Automatic terminals with network-tone detectors B.6.5 Power failure . Connection methods . Frequencies for customers meter operation . Annex C . European network tones C.2 Ringing tones C.3 Busy tones C.5 Special information tones . C.l Dial tones C.4
29、Congestion tones C.6 C.7 Call in progress tone . Tones for other purposes Annex D . D.l Analogue 4-wire interfaces to a public network . Annex E . Remote user network interface E.1 Scope Page 35 37 38 41 42 42 45 48 54 55 55 56 59 59 63 64 65 65 67 67 67 67 68 68 69 69 69 70 71 72 73 73 76 76 76 76
30、E.2 References E.3 Abbreviations . E.4 Introduction ES Requirements Line characteristics d.c. characteristics requirements in the quiescent state . ES . 1 E.5.2 E.5.3 E.5.4 Requirements in the Loop state . Requirements in the ringing state E.6 Transmission charactenstics . E.7 Metering . E.7.1 Frequ
31、ency E.7.2 Level E.8 Payphone option . Annex F - Telephone network interfacing in the United States of America . F . 1 Introduction F.2 References F.3 Abbreviations . F.4 d.c. conditions . F.4.1 Battery supply Battery connections at a 4-wire interface F.4.2 F.5 Interface states 7.5.1 Idle state F.5.
32、2 Service Request state . F.5.3 Addressing state Ringing and Alerting state . F.5.4 Call Processing state F.5.5 F.5.6 communication state . Page 76 76 77 77 77 77 77 78 79 79 79 79 79 80 80 80 81 81 81 82 82 82 82 83 83 83 83 STD.ITU-T RECMN I-572-ENGL 2000 m 48h2592 Ob88744 579 II ITU-T Recommendat
33、ion 1.572 VSAT interconnection with the PSTN 1 Introduction This ITU-T Recommendation considers the intenvorking of VSAT systems with the public telephone network, usually referred to as the PSTN. Interworking Recommendations for VSAT intenvorking to ISDNs ITU-T Recommendation 1.57 1 and PSPDNs ITU-
34、T Recommendation X.361 already exist. VSAT technology can be deployed in both public Access networks and private networks. VSAT technology offers fast deployment and the capability to communicate with any customer irrespective of location (sometimes referred to as high penetration capability). The P
35、ublic Switched Telephone Network (PSTN) is a concept that embodies all national and international telephone networks. In practice it is not possible to connect to a “concept“; therefore practical connections are always to a National telephone network that operates within a National regulatory kamewo
36、rk. This Recommendation only deals with the technical functional requirements for interconnection to National telephone networks and not with the multitude of other issues related to interconnection with National telephone networks, such as financial issues or the universal service requirement or ot
37、her national policy issues, Telephone networks have been in existence for a long time and therefore they usually offer the end user a wide range of interfaces and features some of which are unique to a particular network within a particular country. There usually exists a set of National telephone n
38、etwork technical interface specifications, that are in the public domain, which specify the Requirements-for-Interconnection to a National telephone network. The classic arrangement for connecting an end user to any national telephone network is via an Access network. The Access network has only rec
39、ently acquired the status of a separate entity in telephone networks due to the influence of national privatization policies which are in the process of introducing competition into many telephone networks. The end user is normally connected to the first level of the switching hierarchy of a Nationa
40、l network, usually referred to as the Local Exchange (LE). This will usually be the nearest exchange to keep access costs as low as possible. However, if the nearest local exchange cannot support the required facilities, then the user may be connected to a more distant exchange that can provide the
41、necessary services. In parts of the world with low telephone densities there may be one or more concentration (and possibly switching) stages within the Access network before the LE, e.g. remote concentrators, Private Branch Exchanges (PBXs) or simply shared service lines. In addition, it may be eco
42、nomic in such an environment to employ higher speed multiplexing techniques to support several channels on one physical channel within the Access network. 2 Scope This ITU-T Recommendation covers the technical fiinctional requirements for the interconnection of VSAT networks to National networks. It
43、 does not include the Regulatory requirements for interconnection to National telephone networks, which are a national matter. Any particular VSAT network may be owned or controlled by the national network operator, or operators, or by a private network operator. Thus the VSAT network may be conside
44、red to be part of the National Access network or part of a private network. STD-ITU-T RECMN I-572-ENGL 2000 W 4862593 0688745 405 = 3 Referen ces The following ITU-T Recommendations and other references contan provisions which, through reference in this text, constitute provisions of this Recommenda
45、tion. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other referen
46、ces listed below. A list of the currently valid ITU-T Recommendations is regularly published. ITU-T Recommendation E. 182 (1 998), Application of tones and recorded announcements in telephone services. ITU-T Recommendation G. 1 O 1 (1 996), The transmission plan. ITU-T Recommendation G. 103 (1 998),
47、 Hypothetical reference connections. ITU-T Recommendation G. 107 (1 998), The E-Model, a computational model for transmission planning. ITU-T Recommendation G. 1 1 1 (1 993), Loudness ratings (LRs) in an international connection. ITU-T Recommendation G. 1 13 (1996), Transmission impairments. ITU-T R
48、ecommendation G. 1 14 (1 996), One-way transmission time. ITU-T Recommendation G. 1 16 (1 999), Transmission performance objectives applicable to end-to-end international connections. ITU-T Recommendation G.117 (1996), Transmission aspects of unbalance about earth. ITU-T Recommendation G. 120 (1 998
49、), Transmission characteristics of national networks. ITU-T Recommendation G. 12 1 (1 993), Loudness ratings (LRs) of national systems. ITU-T Recommendation G. 122 (1 993), Influence of national systems on stability and talker echo in international connections. ITU-T Recommendation G. 126 (1993), Listener echo in telephone networks. ITU-T Recommendation G. 13 1 (1 996), Control of talker echo. ITU-T Recommendation G. 142 (1 998), Transmission characteristics of exchanges. ITU-T Recommendation G. 165 (1 993), Echo cancellers. ITU-T Recommendation G. 168 (1997), Digital network e
