1、 STD-ITU-T RECMN 1.432-5-ENGL 1997 W 4862591 Ob37375 O20 D INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU SERIES I: INTEGRATED SERVICES DIGITAL NETWORK ISDN user-network interfaces - Layer I Recommendations 1.432.5 (0697) B-ISDN user-network interface - P
2、hysical layer specification: 25 600 kbit/s operation ITU-T Recommendation 1.432.5 (Previously CCITT Recommendation) STD-ITU-T RECMN I-i32.5-ENGL 1777 q8b2571 Ob3737b Tb7 ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERALSTRUCTURE Terminology Description of ISDNs General model
3、ling methods Telecommunication network and service attributes General description 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 Netwo
4、rk functional principles Reference models Numbering, addressing and routing Connection types Performance objectives Protocol layer requirements General network requirements and functions Application of I-series Recommendations to ISDN user-network interfaces Layer 2 Recommendations Layer 3 Recommend
5、ations Multiplexing, rate adaption and support of existing interfaces Aspects of ISDN affecting terminal requirements SERVICE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS ISDN USER-NETWORK INTERFACES ecommen INTERNETWORK INTERFACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment
6、Management of ATM equipment I. 1 00-1.1 99 I. 1 10-1.1 19 I. 120-1.129 I. 130-1.139 I. 140-1.149 I. 150-1.199 I .200-I. 299 1.200-1.209 I .2 1 04.2 1 9 I. 220-1.229 I .230-1.239 I .240-1.249 1.250-1.299 I .300-1.399 1.310-1.319 1.320-1.329 I. 3304.339 I. 340-1.349 I .350-1.359 I .36O-l.369 I. 370-1.
7、399 I .400-1.499 1.420-1.429 I .440-1.449 I .45O-l.459 I .46O-l.469 I .470-1.499 I SOO-I 599 1.600-1.699 I .700-1.799 1.730-1.749 1.750-1.799 For further details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN 1-432-5-ENGL 1777 D 4Bb259L Ob37377 7T3 ITU-T RECOMMENDATION 1.432.5 B-ISD
8、N USER-NETWORK INTERFACE - PHYSICAL LAYER SPECIFICATION: 25 600 kbit/s OPERATION Summary This Recommendation covers physical layer characteristics for transporting Asynchronous Transfer Mode (ATM) cells at a nominal bit rate of 25 600 kbit/s over 100 ohm UTP, 120 ohm, and 150 ohm STP twisted pair ca
9、bles at the SB reference point of the B-ISDN User Network Interface (UNI). The maximum distance is approximately 100 m. This Recommendation may be used to take advantage of existing building wiring. Functionality is presented in terms of Physical Media Dependent (PMD) and Transmission Convergence (T
10、C) sublayers, using a cell-based format. This Recommendation is part of the 1.432-Series Recommendations, and includes references to Recommendation 1.432.1 3 on general characteristics, and Recommendation 1.432.2 4 on transmission convergence sublayer aspects. Source ITU-T Recommendation 1.432.5 was
11、 prepared by ITU-T Study Group 13 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 20th of June 1997. - STDmITU-T RECMN 1.Y32.5-ENGL 1777 48b259L 0b37378 83T FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of tel
12、ecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of 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 Wor
13、ld Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid
14、 down in WTSC Resolution No. 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 telecomm
15、unication administration and a recognized operating agency. 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 IT takes no position concerning the evidenc
16、e, validity or applicability of claimed Intellectual Property Rights, whether asserted by IT members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the IT hadhad not received notice of intellectual property, protected by patents, which
17、 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 1997 All rights reserved. No part of this publication may be reproduced or utilized in
18、any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the IT. 11 Recommendation 1.432.5 (06/97) STD-ITU-T RECMN 1.432-5-ENGL 1777 W 4Bb257L Ob37377 77b W CONTENTS 1 1.1 1.2 2 2.1 2.2 2.3 2.4 3 3.1 3.2 3.3 3.4 4 Introduction Scope
19、 Reference configuration . layer interface . Transmission link requirements . Physical media characteristics at the S, reference point for 25 600 kbitls physical 2.1.1 Line and bit rates . 2.1.2 Bit rate symmetry 2.1.3 Bit Error Ratio (BER) . : . 2.1.4 Transmission link timing . Free running timing
20、configurations . Transmitter requirements 2.2.1 Transmitter zero-crossing distortion . 2.2.2 Transmitter waveshapes 2.1.5 2.2.3 Transmitter launch amplitude 2.2.4 Transmitter return loss Receiver requirements 2.3.1 Receiver acquisition timing . 2.3.2 Receiver return loss . Copper link segment charac
21、teristics . 2.4.1 100 ohm link segment . 2.4.2 2.4.3 . 120 ohm link segment . 150 ohm link segment . Functions provided by the transmission convergence sublayer . Cell scrambling and descrambling . 3.1.1 PRNG sequence . 4B5B block coding and decoding . Symbol-pair level code structure . Support for
22、a timing signal NUI encoding and decoding . HEC generation and verification 3.2.1 3.2.2 Cell delineation . 3.2.3 References Page 1 1 1 2 2 2 2 4 4 5 10 10 11 11 11 11 11 14 15 16 17 19 19 20 21 21 22 22 23 Recommendation 1.432.5 (06/97) iii STDSITU-T RECMN 1.432.5-ENGL I777 m 48b257L 0b37380 478 m B
23、ibliography . Definitions Abbreviations . Page 23 24 24 iv Recommendation 1.432.5 (06/97) STD-ITU-T RECMN 1.432.5-ENGL 1997 m 48b257l1 Ob37381 324 m Transmission Convergence (TC) sublayer Physical Media Dependent (PMD) sublayer Recommendation 1.432.5 HEC generation/verificTtion Cell scrambling/descr
24、ambling Line coding/decoding Cell delineation Cell rate decoupling Bit timing Physical media Connectors B-ISDN USER-NETWORK INTERFACE - PHYSICAL LAYER SPECIFICATION: 25 600 kbis OPERATION (Geneva, 1997) 1 Introduction 1.1 Scope This Recommendation covers physical layer characteristics for transporti
25、ng Asynchronous Transfer Mode (ATM) cells at a nominal bit rate of 25 600 kbits over 100 ohm UTP, 120 ohm, and 150 ohm STP twisted pair cables at the S, reference point of the B-ISDN User Network Interface (UNI). The maximum distance is approximately 100 m. This Recommendation may be used to take ad
26、vantage of existing building wiring. The physical layer functionality is divided into a Physical Media Dependent (PMD) sublayer and a Transmission Convergence (TC) sublayer. The PMD sublayer provides the definitions for the transmitter, the receiver, timing recovery, media interface connector and th
27、e transmission media. The TC sublayer defines the line coding, scrambling, data framing and synchronization (see Table 1). Table 1n.432.5 - Functions of the TC and PMD sublayers The term “bit rate“ used throughout this Recommendation refers to the logical information rate, before line coding. The te
28、rm “line symbol rate“ will be used when referring to the rate after line coding (25 600 kbit/s bit rate results in a 32 Mbaud line symbol rate after 4B5B encoding). 1.2 Reference configuration The reference point SB of the B-ISDN customer access is defined in Recommendations 1.413 2, 1.414 6, and 1.
29、432.1 3. 2 Physical media characteristics at the S, reference point for 25 600 kbis physical layer interface 2.1 Transmission link requirements 2.1.1 Line and bit rates The nominal line symbol rate is 32 Mbaud. Due to the use of the 4B5B block code, the bit rate is 25 600 kbit/s. Recommendation 1.43
30、2.5 (06/97) 1 The transmitter at the customer side should use a fi-ee-running transmitter clock that operates at the nominal bit rate within a tolerance of I1 O0 ppm. 2.1.2 Bit rate symmetry Interfaces are symmetric; i.e. the bit rates are the same in both transmit and receive directions. 2.1.3 Bit
31、Error Ratio (BER) The active input interface should operate at a BER not to exceed lo- when presented with a transmitter described in 2.2 and transmitting through the channel reference model described in 2.4 in the presence of the worst-case crosstalk noise given in 2.4. Measurement of BER is normal
32、ly performed out-of-service. In-service measurements based upon different parameters, e.g. block errors, background block errors, etc., are under study. 2.1.4 Transmission link timing Figure 1 illustrates the conceptual components of the TCPMD and the timing source. The TCPMD uses a local crystal os
33、cillator or a distributed low jitter timing reference that supports a nominal transmission rate of 25 600 kbits. 2.1.5 Free running timing configurations The recommended approach is to use point-to-point timing where the transmit clock on each end of a link is independent, as depicted in Figure 2. U
34、nder these conditions, the pulse waveform templates of 2.2.2 bound the acceptable pulse shapes to be found on any link. 2 Recommendation 1.432.5 (06/97) STD-ITU-T RECMN 1.432.5-ENGL 3997 W 48b259L b37383 IT7 m Stripping descrambling 4B5B decoding deserializing NRZI decoding AA Data Filter, amp, equa
35、lizer Data latch Ru line D A - Clock - PLL Timing recovery Transmit cells Crystal or Formatting scrambling lowjitter + 4B5B encoding timing serializing NRZI reference encoding TC PMD Driver, filter Tx line timing 3 Recommendation 1.432.5 (06/97) STD-ITU-T RECMN I.i32.5-ENGL 1997 W 48b259L b37389 033
36、 m / Network equipment Low jitter timing reference Low jitter timing reference Timing User device or network equipment 1 T1308210-96 Figure 2A.432.5 - User device - network equipment timing configurations 2.2 Transmitter requirements These recommendations place requirements on the transmitted signal
37、. Measurement to these parameters will require that a means exists to send unscrambled, unencoded data streams at the line symbol rate through the transmitter circuitry. For all transmitter measurements, the transmitter should be terminated in a 100 ohm resistive load for 1 O0 ohm UTP Recommendation
38、s. The transmitter should be terminated in a 150 ohm resistive load for 150 ohm STP Recommendations. The transmitter should be terminated in a 120 ohm resistive load for 120 ohm recommendations. Unless stated separately, the parameters given below apply to all of the 100, 120, and 150 ohm measuremen
39、ts. 2.2.1 Transmitter zero-crossing distortion Duty cycle distortion is intended to measure the static, non-data-dependent distortion in the data edge zero-crossings typically caused by asymmetrical propagation or rise/fall times of transmitter logic or 4 Recommendation 1.432.5 (06197) in the conver
40、sion from a single-ended to a differential data stream. Edge jitter is intended to measure the dynamic and data dependent distortion in the data edge zero-crossings typically caused by transmit filtering and noises internal and external to the transmitter circuitry. A B C 2.2.1.1 Duty cycle distorti
41、on Duty cycle distortion applies to the transmitted data stream given below and is defined as one half the difference in the positive and negative pulse widths of the AC coupled transmitter waveform. NOTE-The waveform given below is only a test waveform for the purpose of measuring the launch amplit
42、ude and should not be construed as a waveform which may be seen during normal operation of the physical layer. The Transmitter Duty Cycle Distortion (TDCD) should be less than 1.5 ns peak when the output is clocked by a local clock source. Two test waveforms (symbol elements at line symbol rate) are
43、 defined to be: 00110011 ., and O 1 O 1 O 1 O 1 These are test patterns only, and they may not be scrambled nor encoded. -0.3 O 0.3 6.3 1.20 10.5 14 1.20 23.0 2.2.1.2 Edge jitter Edge jitter applies to any waveform compliant with the scrambling and encoding recommendations in clause 3. It is defined
44、 as the maximum of the peak variation of the rising edges of data relative to the transmit clock and the falling edges of data relative to the transmit clock. The Transmitter Edge Jitter (TEJ) should be less than 4 ns peak-to-peak when the output is clocked by a local clock source. D E F G H 2.2.2 T
45、ransmitter waveshapes The transmitter wave shape should conform to the waveform templates defined in Tables 2 to 6 below. An additional constraint is that the worst case 3 dB comer frequency of the transmitter output should be less than or equal to 12 kHz. Figures 3 to 7 and the corresponding Tables
46、 2 to 6 below list and plot the data points that define the pulse templates. NOTE - Amplitude is expressed as the measured pulse amplitude normalized such that the value 1 on each graph represents the amplitude of the fundamental frequency for the single symbol element. Time is expressed in percent
47、of the measured pulse width. With a line symbol rate of 32 Mbaud, the nominal line symbol width is 3 1.25 nanoseconds. (Therefore, for example, the nominal duration - corresponding to the 100% mark - for the five-symbol element is 156.25 nanoseconds.) 23 1 .O5 36.0 34 1.20 53.0 56 0.95 87.0 95 0.92
48、99.7 - 100.3 O Table 2fl.432.5 - Template for five-symbol element waveform Lower amplitude 0.60 I Recommendation 1.432.5 (06/97) 5 6 Point Upper time (%) Upper amplitude STDOITU-T RECMN I*q32-5-ENGL 1797 D Lidb259I.t Ob373Bb 70b Lower time (%) Lower amplitude TI 308220-96 Time YO Figure 3D.432.5 - P
49、ulse template for Table 2 five-symbol element waveform -0.4 I O I 0.4 I O I 7.9 I 1.20 I 13.1 I 0.90 I 17 I 1.20 I 28.0 I 0.50 I E 43 1.20 66.0 0.60 F 70 0.95 84.0 0.60 G 93.5 0.92 99.6 O H 100.4 O Recommendation 1.432.5 (06/97) Figure -0 3 4- O 20 40 60 80 100 T1308230-96 Time % 4fi.432.5 - Pulse template for Table 3 four-symbol element waveform 0.8 0.6 0.4 0.2 O lo0 Table 4D.432.5 - Template for three-symbol element waveform I I I I I I Recommendation 1.432.5 (06/97) 7 1.2 1 0.8 0.6 0.4 0.2 O A B C D E F B C E -1 .o O 1 .o 15.5 1.20
