6.6　Splicing，Entry and Termination of Optical Cables

6.6.1　The splicing of optical cables shall be in accordance with the following requirements.

1　Optical cable closures shall comply with the requirements stipulated in the current national standard GB 16529 Splices for optical fibers and cables and YD/T 814 Closure for optical cable.

2　The splicing and diverging of the outdoor optical cables shall use optical cable closures.The closures adopt sealed waterproof structures，which shall be anti-corrosive，with strong capabilities to resist certain level of pressure，tension，and impact force.

3　For splicing of optical cables and fibers in long distance and local networks，welding method should be adopted.Same method should be applied to access networks；however，if actual conditions are not adequate for welding method，mechanical connect method may be used.

4　The attenuation of optical fiber fixing joints shall be controlled strictly，according to factors such as the type and quality of optical fibers，the length of optical fibers and planning for network expansion.Optical fiber splicing attenuation shall meet the requirements in Table 6.6.1.

Table 6.6.1　Welding attenuation thresholds for optical fibers

Notes：1　The average statistics domain of single fibers refers to the all optical fiber splicing loss in a repeater section.
2　The average statistics domain of optical fibers in ribbon refers to the all optical fiber splicing loss in a repeater section.
3　The average attenuation of single fibers using mechanical connector shall not be greater than 0.2dB.
4　Closures shall be installed at locations that are safe and easy for maintenance and repairing.
5　Optical cable closures in man holes shall be installed above the highest waterlog level.

6.6.2　The entry and termination of optical cables shall meet the following requirements.

1　Indoor optical cables shall adopt flame retardant outer sheath.If outdoor optical cables are imported directly into equipment rooms，strict fire prevention measures shall be taken.

2　If outdoor optical cables with metal sheath and strengthening components are imported into equipment rooms，ground handling shall be arranged for the metal components of optical cables.

3　Adequate allowance shall be reserved when laying optical cables to cross earthquake proof seams in large equipment rooms or pivotal buildings.

4　In ODF racks，metal components are connected to the high-voltage protective grounding devices with copper wires no less than 6mm2.Multi-strand copper power cables no less than 35mm2，are guided to the first level of grounding tandem lines in equipment rooms or the total grounding tandem lines in small stations.