Getting to Know FTTx Network

Compared with copper wire, optical fiber’s dominant advantage is the overwhelming information carrying capability, and its high bandwidth and low attenuation easily offset its higher cost. FTTx (fiber to the x) architecture is a typical example of substituting copper by fiber in high data rate traffic. FTTx is a generic term for any broadband network architecture that uses optical fiber to replace all or part of the usual metal local loop used for the last mile telecommunications. The x can be substituted by another letter determined by the delivery topologies that are categorized according to where the fiber terminates. What are the termination places and which letter can be used to substitute x? This article will introduce some FTTx terms.

Different FTTx Architectures

Usually the FTTx items that we are going to introduce are used loosely, as some relate to each other, or just acronyms. Generally the FTTx configurations may fall into two groups: fiber laid all the way to the premises/home/building (FTTP/FTTH/FTTB) and fiber laid to the cabinet/node (FTTC/FTTN), with copper wires completing the connection. Also there are some other FTTx topologies, such as FTTZ (z for zone) and FTTD (d for desktop). The following figure shows simplified schema for four most common FTTx architectures.


FTTP: fiber-to-the-premises, is a loosely used term, which can encompass both FTTH and FTTB or sometimes is used a particular fiber network that includes both homes and businesses. It depends on how the context is used and specific location of where the fiber terminates. FTTP can offer higher bandwidth than any other broadband services, so operators usually use this technology to provide triple-play services.

FTTH: as indicated by the name fiber-to-the-home, fiber from the central office reaches the boundary of the living space, such as a box on the outside wall of a home. Once at the subscriber’s living or working space, the signal may be conveyed throughout the space using any means, such as twisted pair, coaxial pair, wireless, power line communication, or optical fiber. Passive optical networks (PONs) and point-to-point Ethernet are architectures that deliver triple play services over FTTH networks directly from a operator’s central office.

FTTB: fiber-to-the-building, -business, or -basement, is very similar to a FTTH. It is a form of fiber-optic communication delivery that necessarily applies only to those properties that contain multiple living or working spaces. The optical fiber terminates before actually reaching the subscribers’ living or working place itself, but does extend to the property containing that living or working place. The signal is conveyed the final distance using any non-optical means, including twisted pair, coaxial pair, wireless, power line communication. FTTB deployment will be the typical for MDU’s and MTU’s (multi-dwelling units and multi-tenant units).

FTTC: fiber-to-the curb or -cabinet, is a telecommunication system where fiber optic cables run directly to a platform near homes or any business environment and serves several customers. Each of these customers has a connection to this platform via coaxial cable or twisted pair. The term “curb” is an abstraction and just as easily means a pole-mounted device or communications closet or shed. Typically any system terminating fiber within 1000 ft (300 m) of the customer premises equipment would be described as FTTC. A perfect deployment example of FTTC is a DLC/NGDLC (digital loop carrier) which provides phone service.

FTTN: fiber-to-the-node or -neighborhood, sometimes identifies and sometimes distinguishes from FTTC. The optical fiber terminates in a cabinet which may be as much as a few miles from the customer premises. Customers typically connect to this cabinet using traditional coaxial cable or twisted pair wiring. The area served by the cabinet is usually less than one mile in radius and can contain several hundred customers. As mentioned before, if the cabinet serves an area of less than 1000 ft (300 m) in radius, the architecture is typically called FTTC/FTTK.

Features of FTTx in LAN Application

Different from a traditional fiber optic network that would be used in local area network (LAN) application, in most FTTx applications, only one optical fiber is used to pass data in two directions. This is very different from the LAN application where the transmit optical fiber sends data in one direction while the receive optical fiber sends data in the other direction. In a LAN application, data transmission over two optical fibers can be simultaneous. However, in an FTTx single optical fiber application, full-duplex operation is typically not possible. Usually half-duplex operation takes place, i.e., part of the time the optical fiber is carrying a signal in one direction and the rest of the time, it is carrying a signal in the other direction. Thus multiple wavelengths are typically used in FTTx systems. The downstream laser is always a different wavelength from the upstream laser. A longer wavelength is used for the former one, such as 1480nm or 1550nm (or both) and typically 1310nm is for the latter one.


FTTx networks have been acknowledged to be the best choice for phone companies, cities, utilities and commercial service providers to upgrade subscriber connection. Fiber optic cables can carry data at high speeds over long distance while copper cables cannot. The data rate connection is usually limited by the termination equipment rather than the fiber itself, permitting substantial speed improvements by equipment upgrades before the fiber itself must be upgraded. FTTx architecture is being more widely deployed in network applications with its reasonable cost and unlimited performance. FS.COM provides a wide range of FTTx PON components, such as cable distribution and termination accessories, network interface device, PON splitters, etc. For more information you may visit our site or contact

Indispensable Solution for FTTx Applications – Fiber Termination Box

FTTx network architecture is now widely applied to telecommunications for long distance transmission. When using the fiber optic pigtails in FTTx network, it is very essential to protect the fiber terminations since fiber joints are fragile and easily contaminated by outside pollution. In response to the problem, an equipment named fiber termination box is created to house the fiber terminations in a safer place. There are also various types of fiber termination box (FTB) solutions for different applications. This article will provide the some detailed information about them to help you select the right device for your project.

Features of Fiber Termination Box

Fiber termination box provides an simple and clear way to manage the incoming and outcoming cables. Fiber bending radius is securely protected inside the box, thus signal integrity is also guaranteed. Since there is enough work room for fiber splicing and adapter patching, it is more flexible for technicians to use this device during work. Fiber termination box is a compact device offering a convenient access for installation, maintenance and subsequent termination. Fiber counts can be varied to satisfy the project requirements. When installed for different occasions, fiber termination box is also designed with different structures.

Classifications of Fiber Termination Box

Four common types of fiber termination boxes are widely used in FTTx networks, here will introduce them one by one. Hope you can find the most suitable type for your application.

Wall Mount Fiber Termination Box

From its name, we can know that this type of fiber termination box is wall-mountable for installation. The box consists of a front door and a side door. Both adapters and splice trays can be installed inside the box. It is typically used for applications like building entrance terminals, pre-connectorized cables, cross-connects, field connector installations, telephone closets, pigtail splicing, CATV, and computer rooms.

wall mount fiber termination box

Rack Mount Fiber Termination Box

Rack mount fiber termination box is rack-mountable to be installed into a rack mount unit. Unlike the wall mount type, rack mount box has a removable top cover which allows the access of splice tray from the upper side. It supports both cross-connect and interconnect architecture, and provides interfaces between outside plant cables and transmission equipment. Other applications including main distributions, intermediate distributions, telephone closets, CATV also supports the utilization of rack mount fiber termination box.


Fiber Splitter Box

Splitting, splicing and terminating can all be done inside a small area of fiber splitter box for both indoor and outdoor use. Fiber splitter box is an optimal solution for network deployment in customer premises applications. It can distribute cables after installing splitters and also can draw out fiber optic cables by direct or cross-connections. Standard plug and play splitters are especially accepted inside the box.


Fiber Distribution Box

Fiber distribution box is the branch splice closure for distribution cables in FTTx network. It is widely applied to applications of aerial OSP network, medium to low-rise MDU buildings exterior attachments, and central riser closets or stairwells attachments of mid-rise to high-rise MDUs. It is a faster and easier solution than traditional OSP closures.


Fiber Termination Box Fiber Capacity

The fiber capacity of fiber termination box is often varied from 2 fibers to 192 fibers. Rack mount fiber termination box is usually available with the maximum fiber capacity of 192 fibers. Fiber splice trays can be stacked on top to increase fiber capacity. Therefore, fiber termination box is also a good solution for high-density applications when multiple fibers need to be well protected.


In summary, fiber termination box is an indispensable solution for FTTx network. Protecting and managing fiber splices and fiber splitters becomes much more efficient and flexible. In addition, choosing the right type of fiber termination box will also benefit the project deployment.

Fiber Protection Sleeve Secures Your Fusion Splices

Fiber optic splicing, especially fusion splicing, has become increasingly important for OSP (outside plant) deployment. The process is by joining the two fiber ends to create longer cable runs. As we know, spliced bare fibers are fragile to be easily breakable. Therefore, a good protection for the spliced fibers during fiber optic splicing is extremely necessary. Luckily, a small component named fiber protection sleeve perfectly solves the issue. It acts like a strong coat for the fiber splices to prevent unpredictable fractures. This post will take you to understand the basic knowledge about fiber protection sleeve.

Construction of Fiber Protection Sleeve

Generally speaking, a fiber protection sleeve consists three parts. The first part is the inner tube made by hot-meltable adhesive. This material can encapsulates the fusion splice joint and provides vibration damping and an environmental seal so as to protect the fiber from damage and contaminants. The second part is a reinforcing strength member outside the inner tube. The strength member can be made of stainless steel, ceramic or non-metallic. It offers extra rigidity to prevent misalignment, micro bending or breakage of the fiber. The third part is the heat-shrinkable outer tube made of cross-linked polyolefin. This tube provides an instant shrink-force and drives the adhesive liner into all areas of the splice and excludes all the air. The following picture shows the structure of a fiber protection sleeve.


How Does It Work?

When the fibers are melt during the fusion splicing, technician will use the sleeve on the melt point as a protection. Once the hot-meltable adhesive tube touches the melted fiber, it also melts to tightly wrap the fiber joint for the filling and sealing functions. Likewise, when the heat-shrinkable tube is heated, it shrinks to wrap the fiber joint, strength member and hot-meltable tube to form a unity preventing moisture and increasing fiber joint’s strength.

Two Types of Fiber Protection Sleeve
Single Fiber Protection Sleeve

This kind of protection sleeve is used for single fibers. Its strength member adopts the stainless steel needles to reduce fiber damage. Typical lengths are 40 mm and 60 mm. The sleeve color is selective, but most people would choose the transparent tube for better inspection of the fiber status.


Ribbon Fiber Protection Sleeve

The ribbon type is to protect ribbon splices of multiple fiber counts. Ceramic strength member is used to support the splices. Fiber counts in a ribbon sleeve vary from 2 to 12 fibers. The length of the sleeve is usually 40 mm. If stronger protection is required, you can choose the ribbon protection sleeves with double ceramic strength members.


Be Aware of These Precautions

While utilizing the fiber protection sleeves, there are some important precautions for operators to know. The benefits of the precautions are about avoiding unnecessary loss and securing the fiber for a long-term use.

  • Point 1, do not leave air bubbles in the protection tube. This ensures the long-term reliability of the fiber splices.
  • Point 2, the tension applied to the fiber should be uniform so that the fiber can stay straight in the protective sleeve.
  • Point 3, the tension applied to the fiber should not be too large in case fiber cracks increase.
  • Point 4, try to avoid fiber twisting. Because this may cause micro-bending and unnecessary fiber loss.
  • Point 5, do not release the tension until the heat-shrinkable tube is completely shrunk, cooled and shaped. This can avoid the uneven heating which leads to fiber bending.

Fiber optic protection sleeve is usually used during the process of fiber optic splicing. Although the sleeve is very small, it provides great support for the fiber joint. Single fiber protection sleeve and ribbon fiber protection sleeve are two common types in the market. All the above are available in FS.COM. If you are interested, please visit the website for more information.

How to Choose Optical Distribution Frame

Due to the development of high speed transmission, demands for high density patching have increased in recent years. However, the management of installed cables still remains a difficult task. To achieve a simpler way of cable organization, people often use the cost-effective optical distribution frames (ODF) to arrange optical cable connections. ODF plays an important part in building a safe and flexible operation environment for optical network. Different kinds of ODFs are provided in the market, but you need to choose the right one according to actual situation.

Functions of ODF

ODF is mainly used for fiber optic terminal splicing, fiber optic connector installation, optical path adjusting, excess pigtail storage and fiber optic cable protection. When cable enters into the rack, ODF should mechanically fix the cable and install the ground wire protection. Fiber optic cables will also be divided into groups for better management. When it comes to the spliced fibers, extra parts will be stored as a coil and the fusion splices are well-protected in the ODF. Adapters and connectors are pluggable and optical path can be freely adjusted or tested. Moreover, enough space of ODF is provided to satisfy a clear connection.

Things to Consider for Choosing ODF

Selecting a right ODF is vital to future applications. Here are some recommended aspects for you to consider before purchasing:

1) ODF Types

Generally, there are three types in terms of its structure. They are wall mount ODF, floor mount ODF and rack mount ODF. Wall mount ODF shapes are like a small box installed on the wall. Because the space is restrained, wall mount ODF only accepts small fiber counts. Floor mount ODF has a fixed and large fiber capacity in a closed structure. Rack mount ODF is more flexible to be installed on the rack to meet your requirements for different cable counts and specifications. This type is frequently used in optical distribution system with 19 inches’ specification to accommodate the size of standard transmission rack.


2) Fiber Counts

High density fiber counts have become the trend for future data center. Today, a single ODF unit usually has 12, 24, 36, 48, 72, 96 or even 144 ports. Customized ODF according to your needs is also available in the market.

3) Easy Management

Using a high density device will definitely increase the difficulty of cable management. ODF should allow for easy access to the connectors on the front and rear ports for quick insertion and removal, which means that ODF must provide adequate space. Besides, ODF should have the right colored adapters to match with optical connectors in case of wrong connections.

4) Good Protection

One basic function of ODF is the protection function. A standard ODF should comprise protection devices to prevent fiber optic connections from dust or stress damages. For instance, the splicing connection is very sensitive to outside environment and is important to the normal operation of a network, so the good quality of ODF protection device is of great importance.


In a word, ODF is now an indispensable equipment for the deployment of optical network. High-density ODF is especially popular in the industry. To find a suitable ODF with a lower price, careful selection is important. This article only provides some basic factors that may affect the application of ODF. For more information, please visit FS.COM.

Overview of PON Network

PON has now became a popular network technology all over the globe. It first came in to being in 1995. The International Telecommunication Union (ITU) standardized two initial generations of PON – APON and BPON. And the advancement of PON network has never stopped. Until now, the recent PON standard of NG-PON2 has been put forward in 2015. With the maturity of PON, people are more easily accessible to networks today. But what does PON exactly mean? What’s the composition of PON network? The following part will give you the answer.

PON, also known as passive optical network, is a technology in telecommunication that implements a point-to-multipoint (P2MP) architecture. Unpowered fiber optic splitters are used to enable a single optical fiber to serve multiple end-points such as customers instead of providing individual fibers between the central office (hub) and customer. According to different terminations of PON, the network system can be divided into fiber-to-the-home (FTTH), fiber-to-the-curb (FTTC), fiber-to-the-curb (FTTB), etc. To be specific, a PON is made up of an optical line terminal (OLT) at the service provider’s hub and a number of optical network units (ONUs) or optical network terminals (ONTs) near end users. And “passive” is just used to describe that no power requirement or active electronic component is included for transmitting signals in the system.


Here are some types of PON that have been used throughout the years:


Its full name is asynchronous transfer mode (ATM) passive optical network. As the original PON system, APON uses ATM technology to transfer data in packets or cells of a fixed size. In APON, downstream transmission is a continuous ATM stream at a bit rate of 155 Mbps or 622 Mbps. Upstream transmission is in the form of bursts of ATM cells at 155 Mbps.


BPON, also known as broadband PON, is the improved version of APON. It adopts wavelength division multiplexing (WDM) for downstream transmission with the transmission rate up to 622 Mbps. It also provides multiple broadband services such as ATM, Ethernet access and video distribution. Today, BPON is more popular than APON.


EPON or Ethernet PON uses the Ethernet packets instead of ATM cells. Upstream and downstream rates of EPON are able to achieve up to 10 Gbps. It is now widely applied to FTTP or FTTH architecture to serve multiple users. With the advantages of scalability, simplicity, multicast convenience and capability of providing full service access, many Asian areas adopt EPON for their networks.


Gigabit PON is the development of BPON. It supports various transmission rates with the same protocol. The maximum data rate of downstream is 2.5 Gbps and upstream is 1.25 Gbps. It is also widely used for FTTH networks. But compared with EPON, its burst sizes and physical layer overhead are smaller.

Advantages of PON
  • Low cost, simple maintenance, flexible extensibility and easy to upgrade. And no need for power during transmission saves a lot for long-term management.
  • Using pure media network avoids the interference of lightning and electromagnetism. Thus PON network is suitable for areas under harsh conditions.
  • Low occupancy of central office resources, low initial investment and high rate of return.
  • As the P2MP network, PON is able to provide a large range of service to plenty of users.

PON network is for sure an effective solution for multiple network users. EPON and GPON are the most commonly deployed PON systems at present. Since people have been seeking for higher bandwidth provisioning, the capability of transmission will be greatly improved in the near future.