1 General Provisions
1.0.1 The code is formulated with a view to standardize documents on telecommunication cable line engineering design and improve the engineering design and management of telecommunication cable line.
1.0.2 The code is applicable to new construction, renovation and extension of land telecommunications transmission systems for outdoor cable line engineering design.
1.0.3 Engineering designs shall be in compliance with the national fundamental construction guidelines and policies on effective use of resources, including land, energy and raw materials.The specifications also attach great importance to the protection of historical relics, natural environment and landscape.
1.0.4 During the construction of telecommunication cable lines, full consideration shall be given to the overall planning, joint construction efforts and resource sharing among multiple parties in order to satisfy the requirements of building a resource-conserving and environmental-friendly society.
1.0.5 The engineering design shall ensure the overall communication quality of the network, supported by advanced technology, cost-effectiveness and security and reliability.In addition, multiple designs shall be proposed and compared in order to achieve economic efficiency and reduce project costs.
1.0.6 The engineering design shall be combined with communication development planning to leverage the existing infrastructure and equipment of the network.The construction scheme, technology scheme and equipment selection shall be based on the network development planning with full consideration to both mid-term and long-term demand and development objectives.
1.0.7 The seismic performance of the communications network shall be considered during the telecommunication cable line construction in regions where over 7（inclusive）degrees of seismic fortification is required in China.
1.0.8 In additional to observe this code, besides, telecommunication cable line engineering design shall comply with the national active relevant standards also.
2 Abbreviations
Acronym in English Full name in English
ADSS All Dielectric SelfSupporting
CPN Customer PremisesNetwork
DP DistributionPoint
FP FlexiblePoint
MDF Main DistributionFrame
ODF Optical DistributionFrame
OPGW Optical Fiber Composite Overhead GroundWire
PMD Polarization ModeDispersion
SN ServiceNode
3 Telecommunication Cable Line Network
3.1 Telecommunication Cable Line Network Architecture
3.1.1 Telecommunication cable line network（Figure 3.1.1）shall include long-distance lines, local lines and access lines, using transmission media such as optical cables and copper cables.
3.1.2 The access net work part（Figure3.1.2）shall include primary cables, secondary cable sand user drop wires, using transmission media such as optical cable sand copper cables.
3.2 Telecommunication Cable Line Network Design
3.2.1 Design of optical cable line network shall comply with the following principles：
1 Optical cable lines shall be safe and reliable, extending downward gradually to provide communications services to end users.
2 In addition to support the communications development planning, the capacity and routing of the optical cable line network shall also consider long-term business demand and development trends of networking technology in order to determine construction scale.
3 The number of fibers for long distance optical cables shall be determined by long-term demand, while local networks and access networks shall be configured based on mid-term demand with sufficient redundancy for potential demand.
4 Design of optical cable lines for access networks shall be conducted upon the basis of distribution of service access points, nature of subscribers, development quantity, density, geographical locations and timeframes.In the meantime, full consideration shall be given to various factors including geographical environment, duct and pole resources, capacity of original cables, and construction methods of broadband optical access networks whilst selecting appropriate routing, topology and fiber distribution patterns.This would be instrumental in building a network that allows flexible arrangement and scheduling, effective utilization of optical fibers and investment saving and supports future development and network maintenance.
3.2.2 While constructing new optical cable（copper）lines, requirements for co-construction and sharing shall be taken into consideration.
3.2.3 Duct methods shall be first chosen when laying optical cable lines in cities and urban areas.In places where duct methods are not feasible, plastic pipe protection, conduits or other suitable ways may be adopted.
3.2.4 Duct or directly buried methods should be adopted when laying optical cable lines in non-urban areas, while aerial methods may also be applied according to the local natural environment and conditions of economic and social development.
3.2.5 Aerial methods may be applied under the following conditions：
1 In areas such as canyons, deep ditches and valleys, steep mountains etc.where duct or directly buried methods cannot guarantee safety.
2 In areas where other existing facilities, either underground or above ground, create difficulties for construction, owners of the original facilities do not permit construction or compensation costs are excessively high.
3 In areas where other laying methods cannot be adopted due to reasons such as protection of the environment and cultural relics.
4 In areas where long-term construction cannot be conducted due to planning for other constructions.
5 In areas where the ground surface is sinking and the geological environment is unstable.
6 In areas where construction costs of duct or directly buried methods are too high, aerial methods can guarantee the safety of the lines and whilst maintaining the local landscape view and the natural environment.
3.2.6 Optical cables type may stay unchanged when duct or directly buried methods are applied over long range and aerial methods are adopted for specific locations.
3.2.7 Optical cables across rivers should adopt bridge ducts, conduits or hanging installation methods.When cable laying cannot use bridges to get cross rivers, methods shall be determined according to the following principles considering site conditions to ensure safety and stability：
1 Directional drilling or underwater optical cables may be used in rivers with suitable riverbed conditions.Per actual situations, structure of optical cables may stay unchanged when using directional drilling methods.
2 Aerial methods may be adopted instead of underwater laying to ensure safety of optical cables.This happens in cases where riverbed is unstable silting changes significantly, other construction planning exists along the river routes or the riverbed soil is not appropriate for construction.
3.2.8 The construction of copper cable line network shall take into account the development trend of high speed access technology and optical access replacing copper access technology.The network shall be constructed based on the capacity of local switching equipment whilst also considering scope of user demand, outgoing direction of the cables, routing as well as distribution area of the cables.
3.2.9 The design of the copper cable line network shall comply with the following principles：
1 Shall give full consideration to the development of communications technology, evaluate and analyze the necessity of cable network construction, and strictly control the coverage scope of copper cables.
2 The capacity and routing of the copper cable line network shall be determined in line with the overall communications planning, considering the need to meet requirements for a number of years and additionally, the need to support the existing and potential projects.
3 Shall consider the integrity of the line network and proactively adopt new technology and new equipment in order to meet the development and changes of the services and the users and ensure the network is reliable, flexible and cost effective.
4 Duct laying method shall be preferred in city areas and shall gradually deploying the line network hidden in the ground in order not to damage the natural environment and landscape.
5 The design of primary cables for users shall be based on the analysis of user quantity, geographies and timeframe.Technical measures for such aspects as different distribution methods, routing, capacity, point of pairs diminishing and construction methods should be adopted so that these cables can constitute a network that can schedule flexibly, offer high pairs utilization rate, save investment as well as facilitating future development, operation, and management.
3.2.10 The copper cable expansions may only be conducted when there are new business requirements that cannot be supported through adjusting the existing network.
