1 General Provisions
1.0.1 This specification is applicable to the design of newly-built SDH long-haul optical fiber cable transmission project; the design for rebuilt and expanded SDH optical fiber cable transmission project may refer to this specification for the implementation.
1.0.2 In the SDH long-haul optical fiber cable transmission project construction, not only requirements in this specification but also those in "Technical Specification of Optical Synchronization Transport Network" shall be implemented.
1.0.3 "Technical Regulations on the Implementation of National Defense Requirement in Basic Construction of Telecommunication" issued by the Ministry of Information Industry shall be also implemented for the basic construction of Telecommunication involving national defense safety.
1.0.4 Telecommunication equipment adopted in the project design shall be obtained with network access license for telecommunication equipment by the Ministry of Information Industry and those which fail to be obtained with shall not be adopted in the project.
Major equipment such as transmission, switching and communication power supply equipment etc. used in the public telecommunication network in areas with the seismic fortification intensity above Intensity 7 (including Intensity 7) shall be obtained with testing certificate for the seismic performance of telecommunication equipment issued by the Ministry of Information Industry and those which fail to be obtained with shall not be used in the project.
1.0.5 Where there is conflict in the implementation of this specification with national requirements, the national requirements shall prevail.
1.0.6 If individual provision in this specification is difficult to be implemented, it shall be put forward in the design with adequate reason and shall be examined and approved by the competent department.
2 Terms and Symbols
English abbreviation Full name in English
ADM Add and Drop Multiplexer
AIS Alarm Indication signal
APC Angle Plane Connection
APS Automatic Protection Switching
AU Administration Unit
AUG Administration Unit Group
BA Booster Amplifier
B3ZS Bipolar with Three-Zero Substitution 3
BBER Background Block Error Ratio
BER Bit Error Ratio
BITS Building Integrated Timing Supply
BITS Bring Into Service Performance Objective
C Container
CLNS Connectionless Network Layer Service
CMI Coded Mark Inversion
DCN Data Communications Network
DDN Digital Data Network
DST Dispersion Supported Transmission
DXC Digital Cross Connect Equipment
EMS Element Administration System
ES Errored Second
ESR Errored Second Ratio
HDB3 High Density Bipolar of order 3
HRDS Hypothetical Reference Section
HRP Hypothetical Reference Path
GPS Global Positioning System
IG international Gateway
IP Interworking Protocol
ITU-T International Telecommunications Union-Telecommunication Standardization Sector
LA Line Amplifier
LAN Local Area Network
LCT Local Craft Terminal
MLM Multi-Longitudinal Mode Laser
MPI Main Path Interface
MTIE Maximum Time Interval Error
NE Network Element
NMS Network Administration System
OA Optical Amplifier
ODF Optical Distribution Frame
OUT Optical Transponder Unit
PA Pre-Amplifer
PC Plane Connection
PCM Pulse Coded Modulation
PCH Pre-Chirp
PDC Passive Dispersion Compensator
PDH Plesiochronous Digital Hierarchy
PEP Path End Point
PMD Polarization Mode Dispersion
REG Regenerator
Rms Radical mean square
Rx Receiver
SDH Synchronous Digital Hierarchy
SES Severe Errored Second
SESR Severely Errored Second Ratio
SLM Single-Longitudinal Mode Laser
SMS Sub Network Administration System
SNCP Subnetwork Connection Protection
SPC Super Plane Connection
SPM Self-Phase Modulation
SSU Synchronous Supply Unit
STM Synchronous Transport Module
TDM Time Division Multiplexing
TM Termination Multiplexer
T-MUX Transparent Multiplexer
TU Tributary Unit
TUG Tributary Unit Group
Tx Transmitter
VC Virtual Container
WAN Wide Area Network
WDM Wavelength Division Multiplexing
3 Transmission System
3.1 Transmission Model
3.1.1 Hypothetical reference path shall meet the following requirements:
1. The longest HRP on international basis between two users (path end points) is 27500km and shall meet those specified in Figure 3.1.1-1; therein two terminal countries and at most four intermediate countries that may be provided with one or two international gateways (inlet or outlet) for each one are involved.
Figure 3.1.1-1 HRP Composition with End-to-end Range of 27500km
2. The longest HRP is 6900km by domestic standards and shall meet those specified in Figure 3.1.1-2; therein the longest HRP of core network (including long-haul network and relay network) is 6800km.
3.1.2 Hypothetic Reference Digital Section (HRDS) is composed of digital sections with certain length and performance specifications as the reference model for index division and shall meet those specified in Figure 3.1.2. As for SDH digital sections, the HRDS is 420km, 280km and 50km respectively.
3.1.3 The link between interfaces at a certain fixed rate, which is composed of one or more digital sections is defined as digital path.
Figure3.1.1-2 The Longest HRP by Domestic Standards
Figure3.1.2 SDH Digital Section and Multiplexing Section
3.2 System Rate and Multiplexing Structure
3.2.1 System rate and nominal capacity shall meet those specified in Table 3.2.1.
Table 3.2.1 SDH Signal Bit Rate
SDH Class Bit rate (kbit/s) Maximum path capacity (Equivalent speech path )
STM-1 155520 1890
STM-4 622080 7560
STM-16 2488320 30240
STM-64 9953280 120960
STM-256 39813120 483840
3.2.2 Basic multiplexing structure shall meet those specified in Figure 3.2.2.
Figure 3.2.2 Basic Multiplexing Mapping Structure
3.3 Transmission System Organization and Station Arrangement
3.3.1 Inter-provincial and intra-provincial trunk transmission system may be arranged according to communication organization requirements.
3.3.2 Reference configuration for transmission systems shall meet those specified in Figure 3.3.2-1.
Figure 3.3.2-1 Reference Configuration for Transmission System
Equipment in the reference configuration for transmission systems may be divided into TM, ADM, REG and Optical Amplifier (BA and PA) or MADM; their functional block diagram shall meet those specified in Figure 3.3.2-2 to 3.3.2-6.
Figure 3.3.2-2 Termination Multiplexer (TM)
Figure 3.3.2-3 Add and Drop Multiplexer (ADM)
Figure 3.3.2-4 Multiple Add and Drop Multiplexer (MADM)
Figure 3.3.2-5 Regenerator (REG)
Figure 3.3.2-6 Optical Amplifying (BA and PA)
3.3.3 Calculation for the length of regenerator section shall meet the following requirements:
1. As for systems whose rate is below STM-64, the design distance of regenerator sections shall meet both requirements on allowable attenuation and dispersion by systems.
1) Actually reach distance of regenerator sections for attenuation-limited systems may be calculated according to the following formula:
(3.3.3-1)
Where,
L- length of the attenuation-limited regenerator section, km;
Ps- optical transmission power of Point S (MPI-S) at the end of life, dBm;
Pr- optical receiving sensitivity of Point R (MPI-S) at the end of life with BER ≤10-12, dBm;
Pp- maximum optical path cost, dB;
∑Ac- total loss of flexible connectors between Point S (MPI-S) and Point R (MPI-R), dB;
Af- average attenuation coefficient of the optical fiber, dB/km;
As- average loss of fixed fusion splicing for optical fiber, dB/km;
Mc - redundancy of the optical cable, dB/km.
2) Actual reach distance of regenerator section for dispersion-limited system may be calculated according to the following formula:
(3.3.3-2)
Where,
L- length of the dispersion-limited regenerator section, km;
Dmax- maximum total dispersion value allowable for equipment between S (MPI-S) and R (MPI-R), ps/nm;
D- fiber dispersion coefficient (ps/nm·km).
2. As for system with the rate of STM-64, the design distance for the regenerator section shall meet the requirements of the allowable attenuation, dispersion and polarization mode dispersion (PMD).
3. Technical development factor should be considered for the determined length of the regenerator section.
3.3.4 Station arrangement shall meet the following requirements:
1. Station types of terminal station, transit station, branch station and regeneration station may be arranged for transmission systems.
2. Stations shall be arranged reasonably according to network structure, technical specification on equipment and service demand.
3. Terminal station, transit station and branch station for the project generally shall be arranged in through-cities of the provincial level and country-level; if necessary, the y may be arranged at other suitable places.
4. Regeneration station for the project shall be arranged at placed with installation conditions.
5. Attention shall be paid to the safety and convenience for maintenance and emergency repair at the station sites.
1) Places with safety guarantee and convenience for attention where is close to the settlements and existing maintenance facility; places where are close to inflammable and explosive building and stacking yard shall not be selected.
2) Places with higher topography, flat terrain and stable soil where are free from flood effect and easy to keep good temperature and humidity environment in the equipment room and suitable for construction; and places with fault, possible collapse and slide, underground mineral resources and historic sites as well as those at edge of soil slope and fossil river course shall be kept clear from.
3) Places where are easy to access and convenient for construction, maintenance and emergency repair.
4) Places shall not be too far deviating from the optical fiber cable route direction and shall be convenient for the lead-up of optical cable and power supply line.
5) Places shall be easy to keep good internal and external environment in the equipment room and must meet the requirements of security, fire-fighting and civil air defense.
6) Places shall be convenient for the installation of ground wire with lower earthing resistivity and away from equipment with strong current and interference as well as lightning protection and earthing devices.
Contents
1 General Provisions
2 Terms and Symbols
3 Transmission System
3.1 Transmission Model
3.2 System Rate and Multiplexing Structure
3.3 Transmission System Organization and Station Arrangement
3.4 Determination of Size and Capacity
3.5 Optical Interface
3.6 Electrical Interface
3.7 Optical Fiber Type and Operating Wavelength Selection
4 Auxiliary System
4.1 Network Administration System
4.2 Synchronous System
4.3 Public Service Communication System
4.4 Auxiliary Channel
5 Network Organization
5.1 Network Organization Mode
5.2 Network Protection
6 Path Arrangement and Connection
6.1 Path Organization
6.2 Network Interface
6.3 Optical/electric Path Connection
6.4 Interworking between SDH and PDH Long-haul Transmission Network
6.5 Interconnect and Interworking
7 Station Equipment Installation
7.1 Station Communication System
7.2 Equipment Selection
7.3 Equipment Configuration
7.4 Equipment Arrangement
7.5 Equipment Installation
7.6 Wiring Requirements and Wire Cable Selection
7.7 Power Supply System and Earthing
7.8 Station Installation Conditions
8 Performance Indexes of Transmission System
8.1 Error Code Performance
8.2 Jitter Performance
8.3 Wander Performance
8.4 Usability Goal
9 Arrangement of Maintenance Tools and Instruments
Appendix A Explanation of Wording in This Code
Appendix B Optical Interface Parameter Specification
Appendix C Electrical Interface Parameter Specification
Appendix D Jitter Performance of SDH Equipment
