1、I INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STAN DARD IZATI ON SECTOR OF ITU SERIES I: INTEGRATED SERVICES DIGITAL NETWORK ISDN user-network interfaces - Layer 1 Recommendations 1.432.2 (02/99) B-ISDN user-network interface - Physical layer specification: 155 520 kbitls and 622 0
2、80 kbitls o pera t i on ITU-T Recommendation 1.432.2 (Previously CCITT Recommendation) ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE Terminology I. 11 0-1.1 19 Description of ISDNs 1.1 20-1.1 29 General modelling methods I. 130-1.139 Telecommunication network a
3、nd service attributes 140-1.149 General description of asynchronous transfer mode 150-1.199 SERVICE CAPABILITIES Scope 200-1.209 21 0-1.21 9 220-1.229 1.230-1.239 1.240-1.249 1.250-1.299 General aspects of services in ISDN Bearer services supported by an ISDN Supplementary services in ISDN Network f
4、unctional principles Numbering, addressing and routing Performance objectives General network requirements and functions Application of I-series Recommendations to ISDN user-network interfaces Layer I Recommendations Layer 2 Recommendations Layer 3 Recommendations Aspects of ISDN affecting terminal
5、requirements Common aspects of services in the ISDN Teleservices supported by an ISDN OVERALL NETWORK ASPECTS AND FUNCTIONS 1.31 0-1.31 9 Reference models 1.320-1.329 1.330-1.339 Connection types 1.340-1.349 I .350-1.359 Protocol layer requirements 1.360-1.369 1.370-1.399 ISDN USER-NETWORK INTERFACE
6、S 1.420-1.429 1.430-1.439 I ,440-1.44 9 1.450-1.459 1.460-1.469 1.470-1.499 INTERNETWORK INTERFACES 1.500-1.599 1.600-1.699 Multiplexing, rate adaption and support of existing interfaces MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS 1.730-1.739 1.740-1.749 1.750-1.799 ATM equipment Transport funct
7、ions Management of ATM equipment For furlher details, please refer to ITU-T List of Recommendations. ITU-T RECOMMENDATION 1.432.2 B-ISDN USER-NETWORK INTERFACE - PHYSICAL LAYER SPECIFICATION: 155 520 kbit/s AND 622 O80 kbit/s OPERATION Summary This Recommendation covers Physical Layer characteristic
8、s for transporting ATM cells at nominal bit rates of 155 520 kbits and 622 080 kbit/s over coaxial cable and optical fibre interfaces at the T, and S, reference points of the B-ISDN User-Network Interface (UNI). The maximum distance is approximately 2 km for optical fibre and approximately 200 m for
9、 coaxial cable. This Recommendation is part of the 1.432 series, and includes references to Recommendation 1.432.1 on general characteristics. Source ITU-T Recommendation 1.432.2 was revised by ITU-T Study Group 13 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 26th of
10、 February 1999. Keywords ATM, B-ISDN, UNI, user-network. Recommendation 1.432.2 (02/99) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of
11、 the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes
12、 the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recorninendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-T
13、s purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation the term recognized operating agency (RUA) includes any individual, company, corporation or governmental organization that operates a public correspondence service. The terms Admini
14、stration, ROA and public correspondence are defined in the Constitution of the ITU (Geneva, 1992). INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU
15、takes no position concerning the evidence, validity or 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, the ITU had not received notice of intellectua
16、l property, protected by patents, which may be required to 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 1999 All rights reserved. No part of this public
17、ation may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation 1.432.2 (02/99) CONTENTS Page Scope 1 1 2 Background . 1 1 3 References Definitions and abbreviations . 2 4.2
18、 Abbreviations . 2 4 4.1 Definitions 2 . 3 5 Reference configuration 6 6.1 Characteristics of the physical media dependent sublayer . Physical medium characteristics of the UNI at 155 520 kbit/s . Bit rate and interface symmetry 6.1.2 Timing . 6.1.3 Jitter and wander . 6.1.4 Electrical interface . 6
19、.1.5 Optical interface 6.1.1 6.2 Physical medium characteristics of the UNI at 622 O80 kbits . 6.2.1 Bit rate and interface symmetry 6.2.2 Timing . 6.2.3 Jitter and wander . 6.2.4 Electrical interface . 6.2.5 Optical interface Functions provided by the Transmission Convergence (TC) sublayer 7 7.1 Tr
20、ansfer capability 7.1.1 SDH-based 7.1.2 Cell-based 7.2 Transport-specific TC functions . 7.2.1 SDH-based 7.2.2 Cell-based 7.3 ATM-specific TC functions . 4 4 4 4 4 4 7 8 8 8 8 9 9 10 10 10 10 10 10 15 20 20 20 20 8 OAM operational functionality Description of signals defined in Recommendation G.783
21、1 O . 8.1.2 Cell delineation signals 20 Maintenance signals as defined in Recommendation G.783 1 O . 8.1.4 Maintenance state tables 21 8.1 SDH-based 8.1.1 . 8.1.3 20 . Recommendation 1.432.2 (02/99) 111 8.2 Cell-based . Description of signals defined in Recommendation 1.610 SI . 8.2.2 Cell delineati
22、on signals . 8.2.3 Maintenance signals as defined in Recommendation 1.610 8 . 8.2.4 Maintenance state tables 8.2.1 9 Power feeding . 9.1 Provision of power . 9.2 Power available at B-NTl 9.3 Feeding voltage 9.4 Safety requirements Page 28 28 28 28 28 35 35 35 35 35 iv Recommendation 1.432.2 (02/99)
23、Recommendation 1.432.2 B-ISDN USER-NETWORK INTERFACE - PHYSICAL LAYER SPECIFICATION: 155 520 kbith AND 622 O80 kbit/s OPERATION (revised in 1999) 1 Scope This Recommendation covers Physical Layer characteristics for transporting ATM cells at nominal bit rates of 155 520 kbit/s and 622 080 kbit/s ove
24、r coaxial cable and optical fibre interfaces at the T, and S, reference points of the B-ISDN User-Network Interface (UNI). The maximum distance is approximately 2 km for optical fibre and approximately 200 m for coaxial cable. The selection of the physical medium for the interfaces at the S, and T,
25、reference points should take into account that optical fibre is agreed as the preferred medium to be used to cable customer equipment. Functionality is presented in terms of physical media dependent and transmission convergence sublayers, and both SDH-based and cell-based formats are included. The g
26、oal is to have maximum commonality between Physical Layer functions at the UNI described in the 1.432-series Recommendations and any functions which may be defined in future at the Network-Node Interface (“I). Implementations should allow terminal interchangeability. 2 Background This Recommendation
27、 was previously contained in Recommendation 1.432 (as published in March 1993), along with material now published as Recommendation 1.432.1. Recommendation 1.432.1 121 contains those general characteristics which are relevant to all B-ISDN transmission systems at the UNI. This Recommendation contain
28、s only those characteristics that are specific to transmission systems operating at 155 520 kbit/s and 622 080 kbit/s. Information on other bit rates can be found in other Recommendations of the 1.432 series. 3 References The following ITU-T Recommendations and other references contain provisions wh
29、ich, through reference in this text, constitute provisions of this Recommendation. 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
30、 of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. i ITU-T Recommendation G.825 (1993), The control of jitter and wander within digital networks which are based on the Synchronous
31、Digital Hierarchy (SOH). ITU-T Recommendation G.703 (1 998), Physical/electrical characteristics of hierarchical digital interfaces. ITU-T Recommendation G.957 (1999, Optical interfaces for equipments und systems relating to the synchronous digital hierarchy. ITU-T Recommendation G.652 (1 997), Char
32、acteristics of a single-mode opticalfibre cable. 121 131 141 Recommendation 1.432.2 (02/99) 1 4 4.1 None 4.2 IEC Publication 825 (1 993), Safety of laser products. ITU-T Recommendation G.707 (1 996), Network node interface for ihe synchronous digital hierarchy (SOH). ITU-T Recommendation 1.36 1 (1 9
33、99), B-ISDN ATMLayer specrJication. ITU-T Recommendation 1.6 1 O (1 999), B-ISDN operation and maintenance principles and functions. ITU-T Recommendation G. 826 (1 999), Error performance paranzeters and objecrives for international, constant bit rate digital paths at or above the primary rate. ITU-
34、T Recommendation G.783 (1 997), Characteristics of Synchronous Digital Hierarchy (SOH) equipment functional blocks. IEC Publication 950 (1 991), Safety of information technology equipment, including electrical business equipment. ITU-T Recommendation 1.432.1 (1 999), B-ISDN User-network interface ph
35、ysical layer specification: General characteristics. Definitions and abbreviations Definitions Abbreviations This Recommendation uses the following abbreviations: AIS ATM AU BER BIP B-ISDN B-NT1 B-NT2 B-TE B-UNI CATV CEC CMI CRC EDC EMC EM1 2 Alarm Indication Signal Asynchronous Transfer Mode Admini
36、strative Unit Bit Error Ratio Bit Interleaved Parity Broadband Integrated Services Digital Network Broadband Network Termination 1 Broadband Network Termination 2 Broadband Terminal Equipment Broadband User-Network Interface Cable Television Cell Error Control Coded Mark Inversion Cyclic Redundancy
37、Check Error Detection Code Electromagnetic Compatibility Electromagnetic Interference Recommendation 1.432.2 (02199) IEC LCD LOF LOM LOP LOS LSB MPH MSB “I NRZ OAM OCD PL PL-OAM POH PSN RDI FEB REI RS-RDI SDH SOH STI STM TBD TFV TP-AIS TP-FEBE TP-RDI UNI vc International Electrotechnical Commission
38、Loss of Cell Delineation Loss of Frame Loss of Maintenance Flow Loss of Pointer Loss of Signal Least Significant Bit Management Physical Header Most Significant Bit Network-Node Interface Non Return to Zero Operations, Administration and Maintenance Out of Cell Delineation Physical Layer Physical La
39、yer Operations, Administration and Maintenance Path Overhead PL-OAM Sequence Number Remote Defect Indication Remote Errored Blocks Remote Error Indication Regenerator Section Remote Defect Indication Synchronous Digital Hierarchy Section Overhead Surface Transfer Impedance Synchronous Transport Modu
40、le To Be Defined Terminal Failure Voltage Transmission Path Alarm Indication Signal Transmission Path Far End Bit Error Transmission Path Remote Defect Indication User-Network Interface Virtual Container 5 Reference configuration Refer to Recommendation 1.432.1 121. Recommendation 1.432.2 (02199) 3
41、6 These characteristics apply to interfaces at the T, and S, reference points. Characteristics of the physical media dependent sublayer 6.1 Physical medium characteristics of the UNI at 155 520 kbit/s 6.1.1 The bit rate of the interface is 155 520 kbit/s. The interface is symmetric, i.e. it has the
42、same bit rate in both transmission directions. The nominal bit rate in free running clock mode is 155 520 kbit/s with a tolerance of k20 ppm. Both optical and electrical interfaces are recommended. The implementation selected depends on the distance to be covered and user requirements arising from t
43、he details of the installation. Bit rate and interface symmetry 6.1.2 Timing 6.1.2.1 SDH-based In normal operation, timing for the transmitter is locked to the timing received from the network clock. The tolerance under fault conditions is 155 520 kbit/s f 20 ppm. 6.1.2.2 Cell-based At the customer
44、side of the interface at the T, and S, reference points, the cell-based Physical Layer may derive its timing from the signal received across the interface or provide it locally by the clock of the customer equipment, The tolerance under fault conditions is 155 520 kbit/s I 20 ppm. 6.1.3 Jitter and w
45、ander For both electrical and optical B-UNIS, the interface output jitter is in accordance with the appropriate limits given in Recommendation G.825 11 for the electrical and optical interfaces. Equipments having an electrical or optical B-UNI (e.g. B-NT1, B-NT2, B-TE), and which meet the input jitt
46、er tolerance and the jitter transfer specifications given in Recommendation G.825 i, are assured of proper operation when the interface output jitter conforms to the limits in Recommendation G.825 i. 6.1.4 Electrical interface 6.1.4.1 Interface range The maximum range of the interface depends on the
47、 specific attenuation of the transmission medium used. For example a maximum range of about 100 metres for microcoax (4 mm dia.) and 200 metres for CATV type (7 mm dia.) will be achieved. 6.1.4.2 Transmission medium Two coaxial cables, one for each direction, are recommended. The wiring configuratio
48、n is point-to-point . The impedance is 75 ohms with a tolerance of I5% in the frequency range 50 MHz to 200 MHz. The attenuation of the electrical path between the interface points I, and I, is assumed to follow an approximate square root (f) law and to have a maximum insertion loss of 20 dB at a fr
49、equency of 155 520 kHz. 4 Recommendation 1.432.2 (02/99) 6.1.4.3 Electrical parameters at interface points I, and I, The digital signal presented at the output port and the port impedance should conforin to Table 12 and Figures 22 and 23 of Recommendation G.703 2 for the interface at 155 520 kbids. The digital signal presented at the input port and the port impedance should also conform to Table 12 and Figures 22 and 23 of Recommendation G.703 2 for the interface at 155 520 kbids, but modified by the characteristics of the interconnecting coaxial pair. 6.1
