Want to be free of all the possible troubles in FTTH? Get these 3 steps done!

Want to be free of all the possible troubles in FTTH? Get these 3 steps done!

FTTH technology provides an ideal platform for high-speed broadband access to users’ homes and brings great benefits to the fixed access network and advanced wireless network. FTTH network is based on optical fibers, which enables numerous end users to share a center office (node or access point) and make the demands for high bandwidth come true. Now, the most cost-effective set of FTTH solution about fiber optic cable selection, cabling deployment, and FTTH installation will concentrate in this post.

  1. Fiber optic cable solution of FTTH

Many people don’t have a clear idea about how to select appropriate fiber optic cables for their FTTH network deployment; basically, there are only two main points that can help you figure it out totally.

  1. What types of fiber optic cables can effectively work for FTTH?

Three kinds of fiber optic cables are normally used for FTTH; they are single-mode fiber optic cable, multimode fiber optic cable as well as bending insensitivity fiber optic cables.

  1. How to get the cost-effective fiber optic cables?

Seen from the above comparison, the single-mode fiber optic cable can most satisfy the demands for FTTH network. However, single-mode fiber optic cable also costs most among the three optical cables, which makes it not adopted sometimes in some FTTH applications. Therefore, for getting the proper fiber optic cables, there are several practical considerations that would help:

  • Network structure

The structure of the network has a significant impact on the data transmission rate and the optical power budget of the network. The supportive data transmission rate and optical power of different fiber optic cables would be different. So choose the appropriate cable type according to the specific network structure.

  • Network size

The size of a network generally refers to the number of end users that the network can support, but in this context, the network size refers to the physical distance between the access point and the end users. In general, single-mode fiber optic cable is for long-distance transmission, multi-mode fiber optic cable is for short-distance transmission.

  • The existing used fiber optic cable type

If you are ready to expand the existing fiber optic network, use the fiber optic cable as same as the original cable type.

  • Longevity

In general, FTTH can last at least 30 years, so choosing a long-life fiber optic cable is very important. In the long run, the high-quality fiber optic cables can greatly save FTTH network operating costs.

  1. FTTH deployment

After getting a set of FTTH devices and cables, you should work out a deployment scheme for FTTH network. Fortunately, we conclude two schemes to deploy FTTH: active Ethernet and passive optical networks, which have their respective advantages and disadvantages. So there will be following the detailed introduction about these two schemes from multiple aspects, and you would learn which one is suitable for your situation.

Active Ethernet

Active Ethernet is a point-to-point network as shown in the following figure, which is a very simple network infrastructure with dedicated fiber-optic lines to connect the central office with network terminals.

There exists a dedicated fiber optic line between each terminal and the central office, so the lines management and maintenance in active Ethernet are quite simple. The advantages of active FTTH network architecture include: network power budget and troubleshooting is extremely easy to estimate; data transmission is more secure and so on.

Active Ethernet architecture and components

The core components of the point-to-point network are the core switches, converged switches, and optical network terminals (ONT). Among them, the core switch is a high-capacity Ethernet switch, which transmits the data, video and audio signals from service providers through the MPLS-based metropolitan area network or regional network to the access network users; the converged switches can be placed at the central office, and also at the indoor entrance or outside depending on the environmental requirements of the network provider. It transmits data to multiple optical network terminals (ONT) at a transmission rate of 1 Mb / s to 100 Mb / s. The following diagram is a common architecture of active Ethernet in the access network.

Passive optical network

A passive optical network is a point-to-multipoint network in which each end user is connected to the optical network through an optical splitter so that active devices are not used throughout the optical distribution network. The advantage of FTTH passive optical networks is that the passive devices can withstand outdoor harsh environments without power supply. For network carriers, the passive devices of the network also make the network operation and maintenance costs greatly reduced. The following figure is a simple diagram of a passive optical network.

Structure and components of passive optical network

Optical line terminal (OLT) is an important component of the passive optical network, usually located in the local exchange. Similar to the active Ethernet, the optical network terminal (ONT) in the passive optical network is also placed on the users’ end. The difference is that its optical network terminal (ONT) is connected to the optical line terminal (OLT) via optical fibers and passive optical devices (optical splitter). Optical network terminals (ONT) can be placed indoors, but also on the street. The following figure is a common architecture of passive optical networks in the access network.

The following table is for the clearer comparison between active Ethernet and passive optical network (PON):

  1. Things must be done before FTTH installation

After determining the FTTH deployment scheme, the next step is to get it installed. In the process of installing the devices and cables, pollution is mostly an issue that can’t be ignored. Because a little contamination in fibers is likely to cause a higher insertion loss and return loss, sometimes even damage the network devices. As a result, to avoid any pollution or damage happen to the network infrastructure, there are some steps have to be done before installation.

  1. Check the fiber optic connector

The interior of the fiber optic connector is highly susceptible to contaminations and damages. Common types of fiber flaws are dust, oil, pits, debris, scratches, etc., which are difficult to see by the naked eye. Therefore, before installing the connector, check whether the connector especially the end face is qualified. The inspection procedure of the fiber optic connector is as below:

  • Check the end face of the connector with a fiber optic microscope.
  • If the end face is contaminated, clean it with dedicated cleaning tools.
  • Check the end face again to ensure it is free of contamination and then install the connector immediately.
  1. Check the fiber optic end face

There are two situations about the fiber end face. One is the fiber end face of fiber patch cable, another is the end face inserted the device or fiber optic adapter panel. For the former, we only need to connect the fiber optic microscope to the connector of the fiber jumper, and then check the end face; for the latter, connect the scanning probe microscope to the device or adapter panel before checking the fiber end face.

  1. Clean the polluted fiber and fiber optic connectors

There are two ways to clean the fiber: dry cleaning and fluid cleaning. When applying the dry cleaning, we can use a variety of cleaning paper or cloth to clean the fiber, it should be noted that not to re-use the paper or cloth, so as not to cause pollution to the fiber.

When applying the fluid cleaning, it requires cleaning solvent and paper. The following are the noted when using cleaning fluid to clean the fiber:

  • It is not suggested to use alcohol to clean the fiber, because it has characteristics of moisture absorption, flammability and non-volatile. The alcohol remained on the fiber is easy to combine with the water molecules in the air, so to pollute the fiber; It is recommended to use fast-flowing, non-combustible sealed cleaning fluid;
  • Do not directly clean the fiber end face in the cleaning solvent. The correct step is to pour a little cleaning solvent to the cleaning paper, and then clean the fiber with the cleaning paper;
  • Use a clean, dry wiping paper to clean the connector’s ferrule;
  • Do not leave the cleaning solvent around the ferrule.
  1. Loss budget

Before starting to install the FTTH network, confirming the loss budget can ensure the installation goes well. The ITU-T G.671 standard specifies the various loss budgets in the fiber link, as shown in the following table, so you can get the total loss before installation.


Either the fiber optic infrastructure of FTTH or the practical deployment, each step is quite significant for the whole FTTH network system, and requires a lot of knowledge of fiber optic technology and products to accomplish it well. Besides that, there still requires sharp eyes to select a reliable FTTH solution provider as there are too many fiber optics sellers to identify a really good one from the first glance, but there are also multiple reputable ones you can trust like www.cozlink.com of Shenzhen, China. This post is not only giving the whole set of knowledge of FTTH, and also concludes the most cost-effective solution to FTTH deployment.

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