What is FTTH Service – Saikat Infotech

FTTH

What is fiber to the home?

Fiber to the home (FTTH), also called fiber to the premises (FTTP), is the installation and use of optical fiber from a central point to individual buildings to provide high-speed internet access. FTTH dramatically increases connection speeds available to computer users compared to other technologies.

FTTH promises connection speeds of up to 100 megabits per second (Mbps). These speeds are 20 to 100 times as fast as a typical cable modem or DSL connections. It could be costly to implement FTTH on a large scale because it requires the installation of new cable sets over the last links from existing optical fiber cables to individual users.

Some communities currently have fiber to the curb (FTTC) services. FTTC refers to the installation and use of optical fiber cable to the curbs near homes or businesses, with a copper medium carrying the signals between the curb and the end users.

How does FTTH work?

The defining characteristic of FTTH is that it connects optical fiber directly to residences, apartment buildings and businesses. FTTH uses optical fiber for most or all last-mile telecommunications. Optical fiber transmits data using light signals to achieve higher performance.

In FTTH access networks, fiber optic cables run from a central office and through a fiber distribution hub. The cables then run through a network access point (AP) and finally into the home through a terminal that serves as a junction box.

FTTH architecture and components

Two types of systems enable fiber optic cables to transmit data using light and make FTTH possible: active optical networks (AONs) and passive optical networks (PONs).

AONs use electrically powered switching equipment to direct signals to specific users. Instead of electrically powered switches, PONs use optical splitters to direct signals. However, PONs still require electrically powered equipment at the source and receiving ends of the network.

Both types are used in FTTH implementations, and each has their benefits, but most FTTH implementations use PONs because they cost less to install and offer high performance.

The network topology of PONs consists of the following:

An optical line terminal (OLT) at the provider’s central office.
Optical network units (ONUs) closer to the end user’s premises.
An optical distribution network in between the OLT and ONU to split and distribute the signal traveling along the PON.

Benefits of FTTH

The main benefit of FTTH is increased network performance. FTTH provides higher speeds over longer distances that older coaxial cables, twisted-pair cables and DSL cannot reach. FTTH also offers significantly higher bandwidth than other connectivity methods.

Some benefits of FTTH’s higher bandwidth capacity include the following:

Improved performance for high-definition video streaming on applications like YouTube and Roku.
Upgrades that don’t require replacing the fiber. Network professionals can update the infrastructure surrounding the fiber without having to update the fiber itself.
Higher speeds over longer distances than previous technologies.
Better performance than other fiber configurations. Fiber directly connects to residences and can complete remaining network segments with Ethernet or coaxial cables.

Fiber to the x

FTTH is a specific version of the term fiber to the x (FTTx), in which the x represents the point in the network at which a fiber optic cable connects to provide service to buildings in the vicinity. In each term, the place where optical fiber stops and transfers the signal to metallic cable begins differs. All versions of FTTx are the driving force behind next-generation access, which means an upgrade to the speed and quality of broadband networks.

FTTH’s name comes from the fact that the cable connects directly to the user’s home. Network professionals often use the terms fiber to the building (FTTB) and fiber to the premises (FTTP) interchangeably with FTTH. The network structure is the same, and the words home, building and premises all describe dwellings to which fiber networks directly connect.

A small distinction between FTTH and FTTB is that FTTH connects optical fibers directly to residences, and one building could have multiple residencies. In FTTB, the optical fibers connect to the building and metallic cables connect to the individual units — such as homes or offices — inside.

Several other versions of FTTx exist:

Fiber to the node (FTTN). A setup in which the optical fiber connects to the network cabinet or node and passes the signal to copper wire at that point.

Fiber to the terminal (FTTT). Fiber optic cables connect directly to desktop equipment in an office.
Fiber to the office. Similar to FTTT, a fiber optic cable connects to a mini switch at a users’ desk in an office. The office usually has several switches throughout the building, managed from one central location.
Fiber to the street (FTTS). FTTS falls between FTTB and FTTC; FTTS transitions to copper wire closer than FTTC but farther away than FTTB, which attaches directly to the building.
Fiber to the distribution point (FTTdp). FTTdp is a mix between FTTC and FTTN. The end of fiber connects to the last possible distribution point before the end user’s premises.

Many other acronyms in the FTTx category exist. But the only major distinction between them is the point at which the fiber cabling ends and the metallic wiring begins.

Fixed wireless differs slightly from FTTH. Instead of switching from fiber optics to a metallic cable at the fiber endpoint, fixed wireless transmits a wireless signal into the home. This eliminates the need for cabling at the last segment of the network, where most costs incur during installation.

Evolution of FTTH

FTTH has grown since the 1980s to accommodate the growing network demands of the modern world. Many fiber cables implemented in the 1980s are still in use today, which is a testament to their flexibility over time. Since the 1980s, fiber technology has become cheaper and easier to install. Today, usage of FTTH and fiber optics continues to increase.

OLT stands for “Optical Line Terminal.” It’s a critical device in a passive optical network (PON) that serves as the endpoint of the network on the service provider’s side. The OLT connects to multiple Optical Network Units (ONUs) or Optical Network Terminals (ONTs), which are located on the customer’s premises. OLTs manage and distribute data, voice, and video services over optical fibers, making them a crucial component in delivering high-speed broadband services in fiber-optic networks.

1. What is ONU?

ONU refers to optical network unit. It is the optical terminal device in the fiber access network, which provides users with multiple service interfaces. The network side of ONU is the optical interface. As for the user side, it’s the electrical interface. Therefore, ONU can transmit optical signals into electrical signals and vice versa. Besides, it’s capable of converting voice signals of D/A and A/D, reusing, processing signals and maintenance management.

Features of ONU:

1. Triple Play Service: Providing data, IPTV (interactive Network TV), VOIP (using IAD, Integrated Access Device) and other services.
2. Receive broadcast data sent by OLT.
3. Collect and cache the Ethernet data that needs to be sent by users and send the data to OLT according to the allocated sending window.
4. Offer abundant remote management capabilities supported by OAM.

2. Where is ONU in FTTx?

According to the different positions of ONU, the access methods of FTTx with LAN can be divided into FTTC, FTTB, FTTH, etc.- FTTC (Fiber To The Curb): ONU is placed in the central office of the community.
– FTTB (Fiber To The Building): ONU is set down in the junction box in the corridor.
– FTTN (fiber-to-the-node): ONU sits at the access point.
– FTTH (Fiber To The Home): ONU is located in the family users’ house.

1. What is ONT?

The meaning of ONT is an optical network terminal, which is a device providing the family with access network. ONT is a separation between the Ethernet network and customer premises.

It can transfer optical signals from OLT (optical line terminal) into electric signals and offer various services such as high-speed Internet, IPTV, VOIP, WiFi, etc. to users.

Besides, sometimes people consider ONT as ONU (optical network unit). But technically, there is still some difference between ONT and ONU. ONT is a terminal device that is located at the user’s end. ONU is a unit and there are probably other networks between ONU and Users.

Difference between ONU and ONT

Generally, ONT is ONU. The ONU can effectively improve the uplink bandwidth utilization of the entire system and configure channel bandwidth based on the network application environment and service characteristics. In this way, it can carry as many terminal users as possible without affecting communication efficiency and quality, improve network utilization and reduce user costs. They both are terminal devices to connect users in a passive optical network.

However, technically, there still are some differences in some aspects. Read on the learn more details.

1. Definition

ONU refers to optical network unit. It comes from IEEE standard.

ONT refers to optical network terminal. It comes from ITU-T standard.

2. Deployment

In a passive optical network (PON), there is a passive optical splitter between OLT and ONU/ONT. The ONU/ONT will collect and cache the Ethernet data that users require. Then, it sends the data to OLT according to the transmitting window assigned. It will also optionally receive data from OLT. The ONU/ONT will respond to OLT if it needs to receive the data.

However, there may be some other networks like Ethernet between ONU and users. The ONU is always set up outdoors. It may be placed in corridors and some public areas.

ONT is deployed on the users’ end directly. You can consider ONT as a part of ONU.

3. Types of ONU/ONT

Due to different functions, occasions and standards, there are various ONU/ONT such as xPON/EPON/GPON ONU, POE ONU, and CATV ONU. Also, according to the deployment occasions, ONU can be classified into SFU, HGU, SBU, MDU, MTU, etc.

Here we will mainly introduce HGU ONU, which is mostly applied in FTTH. For instance, the V-SOL 4GE+1POTS+ac WiFi+USB HGU ONU is designed for fulfilling the demand for FTTH and triple-play service.

The deployment strategy of the HGU ONU terminal is similar to the SFU ones except that the functions of the ONU and RG are integrated in hardware. Compared with SFU, it can realize more complicated functions of control and management.

1. ONU (Optical Network Unit)

An ONU (Optical Network Unit) is a device that connects a customer’s premises (home, office, etc.) to a fiber optic network, specifically in Fiber to the Building (FTTB), Fiber to the Curb (FTTC), or Fiber to the Home (FTTH) networks. It is part of the Customer Premises Equipment (CPE) and serves as the interface between the optical network (the fiber optic infrastructure) and the customer’s network (typically Ethernet, Wi-Fi, or other local networks).

Function: Converts optical signals from the fiber network to electrical signals for local area network (LAN) devices (e.g., computers, routers, phones).
Location: The ONU is typically located inside a building or at the subscriber’s premises.
Use Case: In FTTB or FTTC setups, the fiber optic cable reaches the building or curb, and the ONU is used to terminate the fiber link inside the building, converting it to Ethernet or other communication protocols.

2. ONT (Optical Network Terminal)

An ONT (Optical Network Terminal) is very similar to an ONU, and in some contexts, the terms ONU and ONT are used interchangeably. However, the term ONT is more commonly used in Fiber to the Home (FTTH) deployments, where the fiber optic cable runs all the way to the end user’s home.

Function: The ONT serves as the endpoint device that connects a customer’s home or office to the optical fiber network.
- It converts the optical signal transmitted over the fiber optic line into an electrical signal (Ethernet, voice, or other data formats).
- The ONT also converts signals from electrical devices (e.g., computers, VoIP phones) back into optical signals for transmission over the fiber network.
Location: Installed at the subscriber’s premises, typically close to where the fiber optic cable enters the building (often in the living room, basement, or a telecommunications room).
Use Case: In FTTH (Fiber to the Home), the ONT is the device that terminates the fiber connection at the subscriber’s home, providing high-speed internet, voice, and video services to the local network.

3. XPON (X-PON)

XPON stands for “any Passive Optical Network” and is a general term for a range of fiber optic technologies that use a passive optical network (PON) architecture for delivering broadband services. It is a broad term that encompasses multiple generations and variants of PON technology, including:

a. GPON (Gigabit Passive Optical Network)

GPON is a widely used PON standard that provides gigabit-speed internet connectivity over fiber optics. It is commonly used in FTTH and FTTB deployments.
GPON offers a 1.25 Gbps downstream and 1.25 Gbps upstream bandwidth.
Deployment: The technology enables operators to deliver high-speed internet, voice, and video services to residential and business customers over a shared fiber optic infrastructure.

b. EPON (Ethernet Passive Optical Network)

EPON is a version of PON that uses Ethernet frames for communication. It is popular in many Asia-Pacific regions and China, and offers speeds similar to GPON.
EPON supports a 1 Gbps downstream and 1 Gbps upstream bandwidth (though newer versions like 10G-EPON offer higher speeds).
Deployment: EPON is often used by internet service providers (ISPs) to deliver internet access and other services.

c. 10G-PON (10 Gigabit Passive Optical Network)

This refers to next-generation PON technologies that support 10 Gbps speeds.
There are different versions of 10G-PON, such as 10G-EPON and XG-PON.
Deployment: 10G-PON is deployed in high-demand environments that require ultra-fast data throughput, such as in business parks, enterprise networks, and next-generation FTTH.

How Do ONU, ONT, and XPON Relate?

XPON refers to the overarching family of PON technologies (GPON, EPON, 10G-PON), which use passive optical splitters to deliver high-speed internet, voice, and video services to multiple users over a shared fiber optic infrastructure.
ONU and ONT are the customer-side devices that connect users to these XPON-based fiber networks.
- In GPON, for example, the service provider uses a GPON OLT (Optical Line Terminal) at the central office or headend to manage the network and allocate bandwidth to multiple ONTs or ONUs at customers’ premises.
- The OLT communicates with the ONU/ONT to provide service to the end user.

Key Differences Between ONU and ONT:

Feature	ONU (Optical Network Unit)	ONT (Optical Network Terminal)
Location	Typically used in FTTB or FTTC setups	Typically used in FTTH deployments
Deployment Environment	Used where the fiber optic cable reaches a building or curb	Installed at the customer’s premises (home or office)
Function	Converts optical signals to electrical signals for local networks	Same as ONU, but primarily used for FTTH services
Typical Use Case	Converts optical signals in fiber to the building or curb setups	Converts signals in fiber to the home setups

Summary:

ONU (Optical Network Unit) and ONT (Optical Network Terminal) are devices that terminate the fiber optic line at the customer premises, providing access to high-speed internet, voice, and video services.
- ONU is commonly used in FTTB (Fiber to the Building) or FTTC (Fiber to the Curb) networks.
- ONT is typically found in FTTH (Fiber to the Home) networks.
XPON (X-PON) refers to the broader family of PON (Passive Optical Network) technologies, including GPON, EPON, and 10G-PON, that allow multiple users to share a single fiber connection while delivering high-speed broadband services.

CATV 1550nm Wavelenth OLT 1310nm

Fiber optic networks are widely used for delivering high-speed internet, CATV (cable television), and voice (telephony) services. The specific wavelengths used for each of these services vary depending on the type of fiber system and the technology being used. Here’s a breakdown of the most common wavelengths used for these services:

1. Common Wavelengths for Internet, CATV, and Voice over Fiber

The wavelengths used for fiber optic internet, CATV, and voice services are typically in the 1310 nm and 1550 nm regions, with some variations depending on the system and the specific service. Here’s a detailed look at the common wavelengths for each application:

1. Internet (Data Transmission)

For fiber-optic internet and data transmission services, the most common wavelengths are:

1310 nm (O-band):
- Used for single-mode fiber connections in many metro and local networks.
- This wavelength is often used for shorter distances (within a city or campus).
- It offers low attenuation and good performance over medium-range links, typically up to 80 km without amplification.
1550 nm (C-band):
- This is the most commonly used wavelength for long-haul fiber optic internet services.
- It provides extremely low attenuation (about 0.2 dB/km in the C-band), making it ideal for long-distance data transmission, typically up to several hundred kilometers.
- 1550 nm is often combined with Erbium-Doped Fiber Amplifiers (EDFAs) to boost the signal over long distances (like in backbone networks or inter-city links).

DWDM (Dense Wavelength Division Multiplexing) systems used for internet backbone networks also leverage multiple wavelengths in the C-band and L-band (from 1525 nm to 1625 nm), allowing the transmission of multiple data streams over a single fiber.

2. CATV (Cable Television)

For fiber-optic CATV systems, the wavelengths depend on whether the fiber is part of a FTTH (Fiber to the Home) or HFC (Hybrid Fiber-Coaxial) network, or part of a fiber-to-the-node system. Here are the common wavelengths used:

1550 nm (C-band):
- 1550 nm is the most commonly used wavelength for fiber-optic CATV because it has low attenuation and is well-suited for long-distance transmission.
- In FTTH or fiber to the node (FTTN) architectures, 1550 nm is used to transmit analog or digital TV signals over fiber, especially in cases where the fiber reaches a central distribution point and coaxial cable is used for the last-mile connection.
- 1550 nm is also used for transmitting video signals using WDM (Wavelength Division Multiplexing). Several TV channels can be carried on different wavelengths in the 1550 nm band.
1310 nm (O-band):
- Sometimes, 1310 nm is used in shorter distance networks for CATV distribution, but 1550 nm is preferred for long-distance fiber optic CATV delivery due to its lower attenuation.
Upstream Wavelengths for CATV:
- In HFC systems, the upstream (return) channel typically operates in the transmission range of return path wavelengths around 1300 nm.
- This is typically for telemetry, user interactions, or for voice services (in VoIP or VoCable systems).

3. Voice (Telephony)

For voice services over fiber optic networks (such as VoIP (Voice over IP) or VoCable), the most common wavelengths used are:

1310 nm (O-band):
- For shorter distance links (within cities or regional networks), 1310 nm is commonly used for both internet and voice services.
- Voice services can be transmitted digitally over fiber as part of the data stream (e.g., VoIP over the internet).
- In some fiber-to-the-home (FTTH) setups, voice signals are transmitted alongside internet and TV signals in a triple-play service using the same wavelength for the internet data (via GPON or EPON).
1550 nm (C-band):
- For long-distance voice services (in large telecommunication networks), 1550 nm is used to transport voice data in the same way it’s used for internet transmission. Voice signals are often carried digitally over the same fiber-optic cable as internet data using WDM or DWDM technology.

Summary of Wavelengths for Internet, CATV, and Voice:

Service	Common Wavelengths	Wavelength Range	Applications
Internet	1310 nm, 1550 nm	O-band, C-band	High-speed internet, long-haul, and metro networks
CATV	1550 nm, 1310 nm	C-band, O-band	Fiber-optic cable TV (FTTH, HFC), video over fiber
Voice (VoIP/VoCable)	1310 nm, 1550 nm	O-band, C-band	Voice transmission over fiber (part of internet services, FTTH)

Additional Details:

GPON (Gigabit Passive Optical Network) and EPON (Ethernet Passive Optical Network) are common FTTH technologies that use the 1310 nm (downstream) and 1490 nm (upstream) wavelengths for data transmission. Voice and video services are often carried alongside data over these networks.
Wavelength Division Multiplexing (WDM) allows multiple services (internet, TV, and voice) to be transmitted over the same fiber using different wavelengths. This is common in both FTTH and HFC systems.

Conclusion:

1550 nm is the most commonly used wavelength for long-distance fiber optic internet, CATV, and voice services due to its low attenuation.
1310 nm is often used for shorter-distance fiber connections and is also suitable for voice and internet in metro and local networks.

1. FTTH – Fiber to the Home

Description: This is the most direct type of fiber optic connection where fiber optic cables are run directly into the home. It is sometimes called pure fiber or fiber-to-the-premises (FTTP).
Key Features:
- Provides the fastest possible speeds and lowest latency.
- Supports high-speed internet, television, and telephone services.
- Requires fiber optic cabling all the way to the user’s residence.
- Typically used in high-speed broadband networks, especially in urban areas and newer residential developments.
Advantages:
- Highest performance with no copper involved.
- Future-proof technology with the ability to upgrade speeds and services as needed.
Disadvantages:
- More expensive to deploy compared to other solutions (e.g., FTTC).
- More time-consuming to install due to the need for fiber cabling directly into each home.

2. FTTC – Fiber to the Curb (or Cabinet)

Description: In FTTC, fiber optic cables are run to a street-side fiber cabinet or curb, and from there, copper cables (usually VDSL or coaxial) are used to connect to individual homes.
Key Features:
- The fiber optic connection only goes partway to the home, typically to a nearby distribution point or node.
- Copper (like VDSL or coaxial) or other wiring is used for the “last mile” to the home.
Advantages:
- Less expensive and faster to deploy than FTTH.
- Can offer significant improvements over traditional copper-based DSL connections.
Disadvantages:
- Limited speeds due to the copper connection, which depends on the distance from the curb to the home.
- Lower performance compared to FTTH because the last segment is not fully fiber-optic.

3. FTTB – Fiber to the Building (or Basement)

Description: In FTTB, fiber optic cables are run into a building (such as an apartment complex or office building), but from there, copper (often Ethernet or coaxial cables) is used to distribute the signal to individual units or offices.
Key Features:
- Typically used in multi-tenant buildings, such as apartment complexes or office buildings.
- Fiber is brought into the building but is not extended all the way to each individual unit (like FTTH).
Advantages:
- Cheaper to install than FTTH because fiber is only run to the building.
- Higher speeds than traditional copper-based DSL or cable networks.
Disadvantages:
- Speeds and performance are dependent on the quality of the internal copper wiring within the building.
- Not as future-proof as FTTH, since it still relies on copper for the last leg of the connection.

4. FTTN – Fiber to the Node (or Neighborhood)

Description: In FTTN, the fiber optic network extends to a central node (often located at a neighborhood or small area level), and from there, the signal is sent to homes using existing copper or coaxial cables.
Key Features:
- Fiber is deployed to a local node or central point, which typically covers a group of homes.
- The last mile of connection uses copper or coaxial cables, like DSL or DOCSIS.
Advantages:
- A cost-effective method of delivering fiber-like speeds to communities.
- Relatively easy and fast to deploy.
Disadvantages:
- Performance varies depending on the distance from the node to the home.
- Speeds drop off significantly the further a user is from the central node.

5. FTTP – Fiber to the Premises

Description: FTTP is a general term used to refer to both FTTH and FTTB, where fiber optic connections are brought directly to the premises (which could be a home or a building).
Key Features:
- It’s a more inclusive term that encompasses both Fiber to the Home (FTTH) and Fiber to the Building (FTTB).
- Fiber optic cable reaches the end-user premises, but the type of installation (directly to the home or to the building) depends on the specific system.
Advantages:
- Offers a high-performance network compared to copper-based connections.
Disadvantages:
- FTTH systems are the most expensive to install, but they provide the best performance.
- FTTB and FTTN offer lower performance than FTTH, but they are less expensive to deploy.

6. PON – Passive Optical Network

Description: While not specifically a “type of FTTH,” PON is an essential network architecture used in FTTH deployments. It allows a single optical fiber to serve multiple homes using splitters.
Types of PON:
- GPON (Gigabit Passive Optical Network): A widely deployed PON standard that supports speeds up to 2.5 Gbps downstream and 1.25 Gbps upstream.
- EPON (Ethernet Passive Optical Network): Uses Ethernet protocols and provides 10 Gbps downstream speeds.
- XG-PON and XGS-PON: Advanced PON standards supporting 10 Gbps and beyond.
Key Features:
- Passive because no active electronics are required between the optical line terminal (OLT) and the optical network units (ONUs).
- Cost-effective due to the use of passive splitters and shared infrastructure.

Summary of FTTH Types:

Type	Description	Fiber Deployment	Advantages	Disadvantages
FTTH	Fiber optic cables run directly to individual homes.	Fiber to the home	Highest speed, future-proof, low latency.	Expensive to deploy, requires significant infrastructure changes.
FTTC	Fiber optic cables run to the curb or cabinet, then copper to the home.	Fiber to curb, copper to home	Lower cost, faster to deploy than FTTH.	Limited speeds due to copper last mile.
FTTB	Fiber optic cables run to the building, then copper or Ethernet to individual units.	Fiber to the building	Cheaper than FTTH, easy to deploy in multi-tenant buildings.	Relies on copper for last mile, lower performance than FTTH.
FTTN	Fiber optic cables run to a local node or neighborhood, then copper to homes.	Fiber to the node	Less expensive, good for neighborhoods.	Speeds drop with distance from the node.
FTTP	General term encompassing both FTTH and FTTB.	Fiber to the premises	High performance across both home and building connections.	Dependent on whether it’s FTTH or FTTB.
PON	A network architecture for FTTH deployments using splitters to share fiber bandwidth.	Shared fiber, passive optical splitters	Cost-effective, supports high-speed multi-user networks.	Performance depends on the number of users in the split.

Conclusion:

In summary, FTTH (Fiber to the Home) is the ideal solution for delivering the highest performance and future-proof broadband, but it is the most costly to deploy. FTTC, FTTB, and FTTN offer more cost-effective alternatives but with lower speeds due to the reliance on copper for the “last mile.” The type of FTTH system selected depends on the budget, speed requirements, and the specific network environment.