Continuously speed up the construction of fiber-to-the-home through technological innovation and cost reduction. EPON technology has been widely recognized in the fiber-to-the-home model. The construction of optical networks in all large and medium-sized cities has been carried out under the necessity of using EPON technology. At present, most domestic operators use FTTB, and terminal access is mainly ADSL carried by copper cable. The broadband speed is limited by the transmission distance of copper cable, and it cannot achieve the ideal Internet speed.
"Telecommunication Fiber-to-the-Home Engineering Construction and Acceptance Specifications (Provisional)" is particularly prominent in the application of terminal laying for the use of sheathed optical cables. It improves the quality and efficiency of design and construction and ensures the stable and reliable use of the network. However, at present, the operators are pre-laying the leather cable in the early stage, and the use of the leather cable mainly belongs to the following four categories:
L type quick connection
quick connect plug
cold splice
The leather cable is connected with pigtail or 86-panel fusion splicing.
The above methods have many unsatisfactory factors in terms of the current construction cost and construction efficiency.
At present, there is a recommended method: leather pigtails - which can solve many problems such as high material cost, slow engineering efficiency, unstable product performance and unreliable quality, and inability to budget for later maintenance costs.
Pigtail
Overview:
After the development of science and technology in the optical communication industry and the promotion of related technologies in recent years, FTTH (Fiber to the Home) has become the final solution mode for the development of optical fiber access networks. It not only meets the development requirements of optical technology in the optical field, but also meets the needs of users High-speed and large-capacity transmission requirements for optical network signals. In the FTTH access project, the mechanical bending properties and tensile properties of conventional indoor optical cables can no longer meet the needs of FTTH (fiber-to-the-home) indoor wiring. In the case of market demand, low-bending radius, high-strength sheathed optical cables have appeared, which will be widely used in FTTH (fiber-to-the-home) access networks.
Features:
In-plant production, good stability and good physical properties of the end face.
Small bending radius, good tensile, anti-interference and anti-side compression performance.
It is easy to open and peel, easy to lay, and easy to put through pipes in the building.
The optical cable is small in diameter and light in weight, and is more beautiful when used indoors.
The pipeline leather cable contains water-blocking material, which can prevent rainwater from being corroded by moisture.
It can be matched with a variety of field connectors, and the field construction time is short.
Unique connector structure, professional production.
After the laying is completed, the construction quality of the leather wire can be measured on site.
Used on the user side, it is beautiful, durable and easy to maintain.
Technical Features:
Insertion loss: ≤0.3dB
Return loss: ≥50dB (APC≥60dB)
Fiber type: G.657 fiber 9/125um
Cable tensile strength: 50N
Optical cable size: 3.1mm×2.0mm (indoor leather cable); 5.1mm×2.0mm (outdoor leather cable);
Pipe line: φ6.8mm inner line size 3.1mm×2.0mm
Working temperature: -25℃～+70℃
Pigtail
Advantages and disadvantages of pigtail fiber
Advantage:
1. Cost control advantages:
1.1 Q: Is the cost of pigtails lower?
A: Yes, the cost of this product is definitely lower than the 4 ways of connecting the leather cable on the market. A cable-retained connector is much less than a quick cold-connect plug or cold-connector. (Even if a flange type is required, an adapter can be added, and the adapter is only a few yuan) A leather cable fixed connector is about 15 yuan, and a cold quick plug is about 60-80 yuan (L-type is nearly 100 yuan) ), a cold splicer plus pigtail costs 40~50 yuan.
1.2.Q: Is there an advantage in the cost of fiber protection of the leather tail compared with the maintenance cost of cold splicing?
A: Yes, the service life of the pigtail fiber is much longer than that of the cold spliced product. The structure of the fixed cable connector is the same as that of the optical fiber connector. The matching liquid is not used inside, and the performance will not be reduced due to the drying of the matching liquid.
1.3. Q: Is the construction cost of pigtails lower than that of cold splice or quick plug?
A: Yes, in addition to the construction cost of the leather cable, the cold connection method also requires the production cost of professional engineers (some operating tools are also indispensable). The use of pigtails only requires the construction cost of optical cable laying, and no other related costs will be incurred.
2. Application scene stability
2.1. Q: Is the pigtail more stable than the cold-connected quick plug?
A: Yes, in terms of technical performance, due to the use of the same method as the conventional pigtail connector, the insertion loss, return loss, end face, including tensile force, and environmental tests are higher than those of the cold-connected quick plug. The return loss of the cable-fixed connector can reach more than 50dB or even higher, the locking mechanism is greater than 40N, the pulling force of the optical cable at the end is greater than 50N, and the cold-connected product is only 4N, the user will have the problem of increased insertion loss or even unusable use. , which are incomparable with cold-connected products.
2.2.Q: What is the comparison of the failure rate between the pigtail and the cold plug?
A: After the fiber-to-the-home development in the early stage, the general users lacked interest and interest in fiber knowledge, which may lead to many users using this cable as a network cable plug. Due to the special structure of cold-connected products, the tensile strength is slightly affected. As a result, users continue to report for repairs, and the repair probability may reach more than 20%. Customers' trust in optical communications will also be affected.
2.3. Q: What are the advantages of pigtails?
A: On-site testing is convenient. ①When the staged acceptance is just completed, the existing connectors can be used to verify on the spot whether there is any damage or fiber breakage during the laying process of the leather cable. ②In the later stage of opening, test the optical cable on the spot. If there is any damage in the previous stage (such as rat bites, poor front laying, etc.), if not, the ONU can be installed quickly, which avoids the user waiting for a long time due to the long construction on site, and effectively eliminates the responsibility for later opening. Attribution issue.
The fixed cable plug has been prefabricated before the connector manufacturer leaves the factory, which can bring convenient installation efficiency for later construction.
2.4. Q: Is it more convenient to use pigtails in construction?
A: Yes. The leather cable is basically made directly by the manufacturer. After arriving at the site, the optical cable can be laid directly. The manufacturer will make products of different lengths according to the needs. It is embarrassing that the same fiber cannot be corresponded to the same fiber in the middle or up and down the building. In the future maintenance, there is a problem of finding the connection between the user end and the connector in the corridor box because there is no serial number.
2.5. Q: Is the scrap rate of pigtails lower than that of cold-connected quick plugs?
A: Yes, ① the scrap rate of the pigtail fiber is all determined by the manufacturer, and the user will not have any risk. As long as the pipe can be properly arranged in the pipe, the connector can meet the tensile strength of the optical cable. ②In the production process of cold splicing, there will be losses or scrapping. The scrapping rate of the initial installation may be as high as 10%, and even in the later stage, it will generally be more than 2%. Once it is scrapped, who should bear the responsibility of the telecommunications or the construction party?
2.6.Q: Can the pigtail be used in the fiber optic panel?
A: Yes, the pigtail can be placed in the optical fiber panel directly instead of the quick cold connector or the L-type quick connector.
2.7.Q: Can the pigtails realize multi-core connectors?
A: Yes. There are 2-core, 4-core and even 8-core multi-core cables. The pigtail can realize multi-core and multi-head connectors. For example, if the optical fiber panel has 2 adapter ports, it can realize 2-core cable connection, while the quick-plug connector can only use single-core cable; 8-core can be used Using the MPO connector, the other end can realize 8-core ribbon outlet, which is introduced when the fiber reaches the terminal, especially the main push method in Europe today.
shortcoming:
Q: Do I need to measure when laying the leather cable?
A: Yes, the leather cable needs to be measured during the construction, but after all, in the preliminary design, the design department has already estimated the number of meters of optical cable per floor for the terminal entering the house, such as 15m-30m. The cost savings of wasted cable meters is limited, and the optical fiber itself will be reserved, even if the cold splicing method has a reserved length.
Q: Is there any limitation in the way of threading the cable plug?
A: Yes, the leather cable plug is generally in the form of pigtail. If the manufacturer supplies double ends, you can ask the manufacturer to make a mark on the part where the number of meters is required. During construction, cut the part of the optical cable, and the head of the connector will go from the top to the top. And lower the cable, and ensure the cable connector is not damaged.
