1、. STD-ITU-T HDBK OFS-ENGL 1989 I 4862593 Ob83207 756 INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CON SU LTATIVE COM M IlTEE Optical Fibres Systems Planning Guide Geneva 1989 E 4862593 Ob81208 b92 INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL
2、TELEGRAPH AND TELEPHONE CONSULTATIVE COM MIlTEE Optical Fibres Systems Planning Guide I Geneva 1989 ISBN 92-61 -031 51 -X STD-ITU-T HDBK OFS-ENGL 3789 9 4862593 Ob81448 030 O I.T.U. m 4862593 0683209 529 OPTICAL FIBRES SYSTEMS PLANNING GUIDE CONTENTS 1 . Introduction General 1.1 1.2 Historical devel
3、opment of optical fibre systems 1.3 CCITT studies on optical fibre systems. 1.4 Optical fibre system planning guide 2 . Characteristics of optical fibre cables. 2.1 2.1.1 2.1.2 2.1.3 2.1.4 2.1.5 2.2 2.2.1 2.2.2 2.2.3 2.3 2.3.1 2.3.2 2.4 2.4.1 2.4.2 2.4.3 2.4.4 2.5 General Introduction Metallic versu
4、s non metallic cables . RecommendationG.652 Single mode versus multimode fibres . Operating wavelength regions . Characteristics of fibres Geometrical and optical characteristics . Transmission characteristics Other characteristics . Characteristics of optical cables . General design criteria . Cabl
5、e performances . Measurement methods for optical fibres and cables Measurement aims and requirements . Transmissiontests . Geometrical and optical tests Mechanical and environmental tests Conclusion . 3 . Active and passive devices for optical fibre systems 3.1 General 3.1.1 Introduction 3.1.2 Gener
6、al requirements for active and passive devices 5 5 5 5 5 6 6 6 6 6 13 17 17 24 27 27 28 32 32 34 35 35 35 35 4b25L Ob8L2LO 240 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 3.2.7 3.2.8 3.2.9 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.7 3.3.8 3.3.9 3.3.10 3.4 3.4.1 3.4.2 3.4.3 3.4.4 3.5 3.5.1 3.5.2 3.5.3
7、3.5.4 3.5.5 3.6 3.6.1 3.6.2 3.6.3 3.6.4 3.6.5 3.7 4 . 4.1. 4.1.1 4.1.2 4.1.3 4.2 4.2.1 4.2.2 4.2.3 Sources Basic principles of semiconductor light emitting devices . III-V materials and processes . Fabrication and packaging Light emitting diodes for single mode optical fibre systems Performance feat
8、ures of telecommunication lasers . Singlemodelasers . Measurement techniques . Reliability Current status Detectors . Basic detection principles Detector materials . Detectors without internal gain: the p-n and p-i-n junction diodes The avalanche photodiode What makes a good detector? . Receive modu
9、les Characterization and measurement . Assembly and packaging . Present day technology . Detectors forthe future Passive and integrated optic devices Modulators . Switches . Couplers . Integrated optoelectronic devices WDM for single-mode fibres General considerations . Component technologies . Sour
10、ces anddetectors Polarization dependences . Summary Connectors . Principles Butt coupling connectors . Fresnel reflections . Expandedbeam connectors . Standardsand current position Standardization . Methodology for system design General System capactiy Network distance distribution . Expansion and u
11、pgrading criteria Quality of service Serveability performance . Availability performance . . Service integrity characterized by transmission performance . 37 37 39 40 41 43 44 46 47 47 48 48 50 51 53 55 57 57 58 58 61 62 62 65 67 69 70 70 71 79 80 80 81 81 81 82 82 82 82 83 83 83 83 84 84 84 84 84 4
12、.3 4.3.1 4.3.2 4.4 4.4.1 4.4.2 4.4.3 4.4.4 4.5 4.5.1 4.5.2 4.6 4.6.1 4.6.2 4.7 Environmental constraints Protection of equipment against the environment Human and environmental protection against harmful effects . Reliability Definition Reliability characteristics Influence of environmental requirem
13、ents . Evaluation of reliability The systems general design . Functions to be performed Design of optical systems . Further considerations for optical fibre systems Adaptation to networks CClTTRecommendations Conclusion . 5 . Practical implemenation of optical fibre systems 5.1 5.2 5.2.1 5.2.2 5.2.3
14、 5.2.4 5.3 5.3.1 5.3.2 5.3.3 5.4 5.5 5.6 5.6.1 5.6.2 5.6.3 5.7 General Fibre optic systems advantages versus application needs Introduction Intracity and intercity trunking Optical submarine systems Local and subscriber-loop systems . Characteristics of practical realizations in optical fibre system
15、s Terrestrial trunks Submarinetrunks . Local and subscriber-loop networks Examples of installed or planned optical systems for the different parts of the network Trends in practical fibre optic system installations . Impacts of fibre optic systems in the public telecommunication networks Application
16、 and network structures . Switching Future needs and potential risks . Conclusion . 6 . System procurement . 6.1 6.2 6.2.1 6.2.2 6.3 6.3.1 6.3.2 6.3.3 6.4 6.4.1 6.4.2 6.4.3 6.4.4 General Alternatives for system procurement . Integration of various sub-systems . Turn-key systems System/sub-system pro
17、curement . Planning criteria Purchasing and evaluation criteria . Contracts and purchase orders Quality and reliability assurance . Clear product requirements . Sound product design Process monitoring Adequate monitoring programme 85 85 87 87 87 87 88 88 88 88 89 96 96 97 97 99 99 99 99 99 100 101 1
18、03 103 105 106 108 109 110 110 111 111 112 113 113 113 113 113 114 114 121 122 123 123 124 125 125 V 48b2591 Ob81212 OL3 6.4.5 6.5 6.6 7 . 7.1 7.2 7.2.1 7.2.2 7.2.3 7.2.4 7.2.5 7.2.6 7.3 7.3.1 7.3.2 7.3.3 7.4 7.4.1 7.4.2 8 . 8.1 8.2 8.2.1 8.2.2 8.2.3 8.2.4 8.3 8.4 8.4.1 8.4.2 8.4.3 8.4.4 8.5 8.6 8.6
19、.1 8.6.2 8.6.3 8.7 8.7.1 8.7.2 8.7.3 8.1.4 8.7.5 8.7.6 8.7.7 8.8 8.9 8.10 Product monitoring Acceptance measurements Conclusion . Plant design and installation General . Outside plant installation . Outside plant design . Installation techniques . Jointing procedures Localization Cable/equipment com
20、patibility Outside plant acceptance test methodology Equipment installation . Central office environment . Remote hub environment . System acceptance test methodology . Safety aspects . Optical sources Optical fibre splinters System operation and maintenance General Alarm monitoring . Alarm detectio
21、n and generation . Alarm correlation and suppression of alarm propagation . Maintenance thresholds Embedded surveillance systems Fault location . Equipmentmaintenance Fault location and verification tests Training of local staff Sparing Installation and removal of additional channels . Performance m
22、onitoring . Alarm transmission interfaces . Parallel interfaces . Man-machine interfaces Machine-machine interfaces . Protection switching . Protection switching implementation . Protection switching performance Switching thresholds . . Protection switch reliability . . Detection and completion time
23、s . Terminal circuit pack protection switching Supplier provided information Routine maintenance Maintenance practices Conclusion . 127 127 129 131 131 131 131 136 138 145 145 146 147 147 147 147 148 148 148 149 149 149 149 149 150 150 151 151 152 152 152 152 152 153 153 154 154 155 155 155 156 156
24、156 157 158 158 158 158 VI 4862591 ObB1213 T5T 9 . Economic and technical considerations . 9.1 9.2 9.2.1 9.2.2 9.3 9.3.1 9.3.2 9.3.3 9.3.4 9.3.5 9.4 9.5 General Technicalevaluation . Criteria for technical comparison Difficulties in technical comparison Criteria for economic comparison . Economic ev
25、aluation methodology . Determination of cost factors . Economiccomparison . Economic considerations on construction and installation . Economic considerations on environmental requirements . Summary of comparison and selection methods Conclusion . 10 . Future trends in optical fibre systems . 10.1 1
26、0.2 10.2.1 10.2.2 10.2.3 10.2.4 10.3 10.3.1 10.3,2 10.4 10.4.1 10.4.2 10.4.3 10.5 10.5.1 10.5.2 10.6 General Advanced optical technologies Introduction Optical sources and detectors . Optical systems . Impactsontodaysdecisions New modulation and detection technologies . High speed IM-DD transmission
27、 technologies . Coherent optical communication systems . Future optical fibre system technologies Introduction Optical amplifier technologies . Optical network evolution Broadband ISDN-based terrestrial networks . Submarine cable system networks Conclusion . Ultra-low loss fluoride glass fibre techn
28、ologies . ANNEX: Case study . A . 1 A.2 A.3 A.4 AS A.5.1 A.5.2 A.6 A.6.1 A.6.2 A.6.3 A.6.4 A.6.5 A.6.6 General Background Routes of optical fibre cables . Junction network requirements Networking strategies of transmission systems . Transmission system configuration strategy . Service protection aga
29、inst transmission line failures Establishments of transmission network Transmission line systems Transmission line network Digital multiplexer systems . Transmission terminal interfaces . Supervisory system for optical transmission network . Results of the project 159 159 159 159 162 162 163 163 164
30、 168 169 170 170 171 171 172 172 172 178 178 178 178 181 186 186 187 190 195 195 198 202 203 203 203 204 206 207 207 208 209 209 211 214 214 214 219 VI1 4862593 Ob81214 996 U A.6.7 Evaluation of the transmission network 219 A.7 Project implementation 227 A.8 Conclusion . 229 References 23 1 VI11 W 4
31、8b2591 Ob81215 822 CHAPTER 1 INTRODUCTION 1.1 General During the past years a new technology has become increasingly used in the field of communication transmission via cables. In contrast to copper cable technology, signals are now transmitted optically with the aid of optical fibres as optical wav
32、eguides. This development has been supported by the availability of suitable semiconductor components such as lasers, light emitting diodes and photodetectors. At the same time, the availability of cost-effective high capacity digital transmission via optical fibres has accelerated the trend towards
33、 an all digital telecommunication network. The exploitation of optical fibre systems in the field has progressed within both national and international telecommunication networks, as well as in local data communication and telemetry environments. During this period tremendous advantage has been achi
34、eved with optical fibres and components as well as the associated optoelectronics and field techniques. The trend will undoubtedly continue and future installations will ensure a wide application of optical transmission technologies in the long-distance, distribution and local networks. 1.2 Historic
35、al development of optical fibre systems The idea of using light to communicate is not a new one, but the modern era of optical communication originated with the invention of the first gas laser in 1960. Compared with conventional sources of light, laser radiation is highly monochromatic and coherent
36、, and very intense. It is thus a natural step to think of its potential as a source for telecommunications. Initially the principal motivation was the enormous bandwidth available, if the laser light is modulated even at a few percent of its fundamental frequency. Experimental unguided optical commu
37、nication systems were developed shortly after the discovery of the laser using light beam travelling through the atmosphere. The disadvantages of this technique include dependence on a clear atmosphere, the need for a line-of-sight path between transmitter and receiver, the possibility of eye damage
38、 to persons who unknowingly look into the beam, and difficulties in focusing the beam. Those reasons caused an interest in optical systems which would guide the light and thus overcome the disadvantages. In fact, at an early stage of studies, glass fibres (although potentially very attractive) were
39、not considered as a suitable transmission medium for optical systems due to the high values of attenuation (several thousand dB/km) experienced with fibres manufactured at that time. There was tremendous effort to reduce attenuation by purification of the materials. This resulted in improved conven-
40、 tional glass refining processes and allowed fibres with greatly reduced attenuation to be manufactured. In 1970, the production of several hundred metres of single-mode fibre having an attenuation of less than 20 dB/km was achieved and, in 1972, it was possible to obtain a multimode fibre having an
41、 attenuation of less than 4 dB/km. The exploitation of wavelengths in the regions between 1100-1600 nm, where the material intrinsic loss is lower, required a shift in optical fibre source and detector technology in order to provide operation at longer wavelengths. At these longer wavelengths, espec
42、ially around 1550 nm, fibres with losses as low as 0.17 dB/km have been reported. Fibre low loss and low dispersion enabled exciting new possibilities for long distance, high bit rate transmission on optical fibres. Research was also stimulated for the development of sources suitable for the new wav
43、elength region. Many different approaches were undertaken, using various combinations of III-V binary, ternary and quaternary compounds. Laser diodes and LEDs are nowadays commercially available, with suitable performance in terms of emitted power, wavelength spectrum and expected life. 1 4862593 Ob
44、BL2Lb 7b9 m The results obtained in the field of optical sources and transmission media have also stimulated studies for the development of corresponding optical detectors. The first generation of detectors had wavelengths between 800 and 900 nm. However, taking into account the considerable advanta
45、ge to be gained from second (around 1300 nrn) and third (around 1550 nrn) window operation, there is a strong research activity at present in the longer wavelength regions, especially concerning wavelengths around 1550 nm. Field use of optical fibre systems requires interconnection devices such as s
46、plices and connectors. There has been a lot of effort to reduce the optical loss introduced by these devices, and the research effort is continuing particularly for single-mode applications. 1.3 CCITT studies on optical fibre systems The potential interest for the application of optical fibres in te
47、lecommunication networks was immediately recognized by the International Telegraph and Telephone Consultative Committee (CCITT), which initiated studies in this field in the 1973-1976 study period. Subsequently, the VI Plenary Assembly of the CCITT (Geneva, 1976) decided to divide the studies on opt
48、ical fibres between Study Group XV (Transmission systems) with its Question 38XV (Physical characteristics of optical fibre cables) and Study Group XVIII (Digital networks) with its Question 13/XVIII (Characteristics for digital line sections on optical fibre cables). The main achievement of the stu
49、dy period 1977-1980 was Recommendation G.651 (?Characteristics of 50/125 pm graded-index optical fibre cables?). For digital line systems on optical fibres it was only possible, during the study period 1977-1980, to agree on a list of parameters to be considered in a possible Recommendation. However, it was recognized that these systems should be in agreement with Recommendations (3.91 1 to G.918 giving the general characteristics for the digital line sections operating at various hierarchical bit rates in order to ensure their international interconnection. The VI1 Plenary Assembly
