FTTH is the foreign language abbreviation of Fiber To The Home, and the Chinese abbreviation is Fiber To The Home. Depending on where the fiber reaches the user side, the application modes (construction modes) of the broadband optical access network include the following, which are collectively referred to as FTTx and mainly include:
(1) FTTN: Fiber To The Node, fiber to the node
(2) FTTZ: Fiber To The Zone, fiber to the cell
(3) FTTCab: Fiber To The Cabinet
(4) FTTC: Fiber To The Curb, fiber to the curb
(5) FTTB: Fiber To The Building
(6) FTTP: Fiber To The Premise, fiber to the customer premises
(7) FTTH: Fiber To The Home, fiber to the home
(8) FTTO: Fiber To The Office
FTTH home fiber patch cord
In different application environments, the optical cables used also have structural differences to meet the special needs of different environments.
Under the traditional FTTX wiring environment. In the process of step-by-step distribution from the central office equipment network, various optical cables and optical fiber jumpers often need to be used alternately. When the central equipment room of the central office goes to the FTTC roadside or the junction box, the backbone cable generally uses the buried layer stranded outdoor armored optical cable with a large number of cores, such as GYTA, GYTS, etc.
After the trunk cable enters the junction box, it passes through the first-level optical splitting, and then the outgoing second-level trunk cable is spliced with the pigtail in the ODF integrated module, and directly enters the FTTB fiber-to-building wiring environment. The secondary trunk cables at this stage generally use outdoor aerial or pipeline optical cables with a small number of cores, such as GYXTW.
In the fiber distribution box or optical distribution box of the corridor, after the secondary trunk cable enters, it is split by the secondary optical fiber or directly spliced with the household pigtail fiber. the final terminal. In this environment, since most families are individual units and the wiring environment is complex, the optical cables used are butterfly-shaped leather cables with smaller cores and more flexible bending to ensure convenient construction. This is what we want today. Mainly introduced, FTTH home fiber jumper.
Before introducing the FTTH home optical fiber jumper, let's briefly introduce the butterfly leather cable.
Leather cable is commonly known as indoor hanging wiring cable. It is to place the optical communication unit (optical fiber) in the center, place two parallel non-metallic reinforcing members (FRP) or metal reinforcing members on both sides, and finally, extrude black or colored polyvinyl chloride (PVC) or low-smoke halogen-free material (LSZH). , low-smoke, halogen-free, flame retardant) sheath. Because its cross section is a symmetrical butterfly shape, it is called a butterfly leather cable. The leather cable is mainly divided into two structures: outdoor self-supporting butterfly leather cable and indoor non-self-supporting butterfly leather cable.
In the traditional FTTH wiring, for the convenience of construction and quick connection, the method of leather cable + optical fiber quick connector has been widely used when entering the house, and the on-site end is completed and the wiring is fast. This method does not need to estimate the length of the jumper in advance, and does not need to use the optical fiber fusion splicer. The construction is really convenient and fast, and it was once the most widely used home access method in FTTH.
However, there are inevitable fatal flaws in optical fiber quick connectors.
One: Since the end of the fiber optic quick connector is connected quickly on site, the tensile force at the connector is not reliably guaranteed, and it is not as good as the fiber jumper with prefabricated ends.
Second: the loss of the optical fiber quick connector is not stable, and its loss is not only related to the quality of the optical fiber quick connector itself, but also has a great relationship with the quality of the fiber cutting by the builder. The fiber port is not flat, which will cause excessive fiber loss. And on-site construction personnel, not every constructor is professional and technically reliable.
Third: In the later stage, in order to solve the problem of uneven ports when the constructor cuts optical fibers, fiber matching paste is generally configured when using optical fiber quick connections to solve the problem of uneven optical fiber cutting ports. However, a new problem has arisen. Since the sealing performance of the quick connector itself is not very good, the optical fiber matching paste also has a service life. The optical fiber matching paste will fail in about 1 year, and the loss will be too large at the interface. In this case, it will cause a lot of trouble for the follow-up optical fiber maintenance.
Due to the above three reasons, the popularity of optical fiber quick connection gradually subsided after a period of time. In the current FTTH environment, only in temporary optical fiber repair and rapid wiring, optical fiber quick connection will be used as a short-term replacement for spare parts. use. And the market of prefabricated FTTH leather fiber patch cords, which were once suppressed by the heat of optical fiber quick connection, became popular again. Although the prefabricated fiber jumper requires the constructor and the buyer to budget the length and quantity of the fiber jumper in advance, its reliable stability has finally won the recognition of the market!
There is a new development of prefabricated patch cords. Because of the above conventional patch cords, most of them are only suitable for use in indoor environments. However, in the actual FTTX wiring environment, the fiber distribution box in FTTB is in many cases. Not in the corridor. Especially now that fiber-to-the-home has begun to spread in rural areas, in many rural wiring environments, FTTB is installed in an outdoor pole-mounted environment, and is pulled into the home overhead. In this environment, the patch cord must be waterproof, and the tensile strength of the interface must be more stringent. Conventional FTTH patch cords are no longer suitable for wiring construction in this environment.
