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.

3.2.11　The capacity of cables on the same route shall be planned on comprehensive basis and setting multiple separate cables is not advised.

3.2.12　The distribution of the copper cable line network shall give priority to cross connecting methods，supplemented by feed-through and free distribution and should not use multiple connections.Cross connections should adopt one level cross connecting and apply to fixed cross connecting areas.The direct service areas within 500 meters around the stations may adopt either feed-through or free distribution.Free distribution methods should be used for full-colored all-plastic cable lines.For the original existing cable lines，if not much adjustment is needed，the original distribution method may be maintained.

3.2.13　Multiple connection shall not be used for primary cables，neither the secondary cables that adopt cross connecting methods.

3.2.14　The utilization rate of each cable pairs for various sections in the design of copper cable line network should comply with the specifications outlined in Table 3.2.14.

3.2.15　The cable pairs should not decline too frequently.For the following situations they should not decline：

1　In areas where extension is difficult；

2　In areas where future development may be planned and where the line equipment needs to be flexible.

3　In areas where the duct and pipe resources are constrained.

3.2.16　The capacity of distribution equipment may be chosen according to finally covered user quantity multiplied by 1.2 to 1.5，combined with the nominal series of the equipment.

3.2.17　The partition of cable cross connection area shall give priority to the geographical conditions and the user quantity covered.The distribution area shall be partitioned，devised or merged in line with long-term and short-term need and balanced approach of technology and economy.It shall consider not only the administration sections of community and neighborhoods under overall city planning，but also the original cross connecting area or distribution area，distribution and routing of cables and optical cables.The scope of distribution areas should not exceed the certain threshold for the sake of secondary cable shortening.

3.2.18　The arrangement of cable wire order and distribution equipment shall start from far to near，and from small to large.