FTTx Network

What Is FTTx Network?

Fiber to the “x” (FTTx) refers to various broadband network architectures that use optical fiber for part or all of their last mile connectivity. The “x” signifies the fiber termination point, covering deployments like FTTH, FTTA, FTTB, and FTTC.

FTTx is a crucial element of next-generation access (NGA), representing the advancement of broadband infrastructure for improved speed and quality of service (QoS).

Figure 1: What Is FTTx Network

The Architecture and Applications of FTTx

Depending on the location of the terminals, the FTTx network architecture or FTTx network types are FTTH, FTTA, FTTB and FTTP, FTTN, FTTC, etc.

FTTH

FTTH, or fiber to the home, is experiencing rapid global expansion. In FTTH deployments, optical cables terminate at the premises, providing direct access to residential and business environments, facilitating easier network utilization for families and offices alike.

Three primary FTTH network structures include home run, active star networks, and passive optical networks (PON).

• FTTH - Home Run architecture involves a direct fiber connection from the central office (CO) to each home or customer. This full duplex optical link is typically more costly due to fiber and electronics needs. It's commonly found in smaller systems like gated communities, utilizing two fibers—one for digital services like Internet and VoIP, and the other for analog CATV. Some also refer to this as a point-to-point or P2P network.

Figure 2: FTTH - Home Run Architecture

• FTTH - Active Star: In an active star network, fiber runs from the central office to a local active node where multiplexed signals are distributed to customers. This setup requires uninterrupted local power at the active node for services like 911. The network is generally more expensive due to the electronics and power requirements, as each customer requires electronic switching and a dedicated optical link to their premises.

Figure 3: FTTH - Active Star Architecture

• FTTH - PON: FTTH utilizes a passive optical network (PON) where multiple customers share a single connection without active components. A bi-directional PON splitter facilitates downstream signals from the central office to all users and combines upstream signals back to communicate with the central office via a single fiber. This splitter, a crucial passive component in FTTH, significantly reduces costs by allowing shared access, making it a preferred architecture for FTTH deployments.

Figure 4: FTTH - PON Architecture

FTTA

FTTA, or fiber to the antenna, is a network architecture that uses fiber optics to transmit signals from a baseband unit (BBU) to a remote radio head (RRH) located near the top of a cell tower. This connection, known as "fronthaul" in 5G networks, is crucial for supporting technologies like massive MIMO (multiple-input and multiple-output), which require extensive cabling and numerous antennas.

Figure 5: FTTA in 5G Application

FTTN

FTTN, short for fiber to the node, describes a network architecture where optical fiber terminates at a street cabinet, and connections to end users are completed using existing copper or coaxial cables. In FTTN deployments, the optical fiber terminates at a node located a short distance from the customer, typically within a few miles. From this node, copper or coaxial cables branch out to connect to individual end users. FTTN encompasses several sub-categories within its broader framework.

Figure 6: FTTN Architecture

FTTC

FTTC, or fiber to the curb, is a variant of FTTN where fiber optics extend from a central office to a distribution point near customer premises, typically located curbside in a pole or enclosure. In FTTC networks, the fiber optic cables terminate relatively close to end users, generally within approximately 300 meters.

FTTB

FTTB, or fiber to the building, refers to deploying optical cabling directly to a building, often used for apartment blocks or large buildings. Unlike traditional FTTH setups, FTTB brings fiber to a node within the building's communication room. From there, existing copper wiring is utilized to extend network connectivity to each office or apartment within the building. This approach allows network operators to achieve a setup close to FTTH while still employing a node architecture, distinguishing it from FTTN and FTTC deployments.

Note: Fiber to the premises (FTTP) is a blanket designation including FTTH and FTTB.

Figure 7: Diagram of FTTx Architecture

FTTx Lifecycle

FTTx networks offer higher transmission rates and lower power consumption. Bringing fiber closer to users maximizes the use of the latest construction, connectivity and transmission technologies. Successful evolution of FTTx networks demands meticulous planning and implementation at every stage.

Design and Planning of FTTx networks

Implementing FTTx technology starts with well-coordinated planning and design. Initially, consider user numbers and locations, fiber paths, access points, and PON technologies. Detailed design elements include junctions, fiber paths, and optical loss calculations. The complete network design should avoid existing infrastructure and identify equipment locations.

FTTx Deployment

Careful planning is crucial for deploying an FTTx network. Tight timelines for installing splitters and splicing cables require detailed attention, accurate labeling, efficient fiber routing, and sound testing practices to avoid delays. While most FTTx components are factory-tested, field testing of seams and endpoints is essential. Poor splices, connector contamination, and microbends can cause optical loss and reduce QoS. An effective installation control plan mitigates these risks.

FTTx Monitoring and Maintenance

After deploying an FTTx network, ongoing monitoring and maintenance are essential to ensure its performance. A single fiber optic link, connecting thousands of clients and carrying sensitive data, requires vigilant oversight. Regular monitoring can enhance security and performance by quickly detecting intrusions and developing long-term strategies to identify trends in fiber quality.

The Future of FTTx

The rapid growth of cloud solutions, smart cities, and 5G networks has driven both operators and consumers to favor high-speed, low-latency fiber optic networks. FTTx infrastructure offers ample capacity and stable connections across all communication modes. Expanding fiber optic network coverage enhances signal transmission over long distances, ensures compactness, and provides immunity to electromagnetic interference.

Unsurprisingly, the deployment of FTTx networks will continue to accelerate. With the unlimited flexibility of "x", numerous potential options for FTTx networks are expected in the future.