Review how the feeder, distribution, and drop sections connect an operator-side access point to subscriber premises, and how route conditions affect the FTTH network architecture.
An FTTH network architecture should be planned as a connected physical path rather than a collection of unrelated cables and boxes. The route begins at an operator-side access location, passes through feeder and distribution sections, and ends at the drop and subscriber termination point.
The exact structure depends on the service area, available pathways, subscriber density, building layout, network capacity, maintenance access, and the approved optical network design. A layout suitable for a new residential development may not be appropriate for an existing apartment building, an aerial suburban route, or a rural service area.
Start with the Network Endpoints and Service Area
The first task is to establish where the optical path starts, where it ends, and which premises must be served. This defines the geographical and physical boundary of the project before individual products are selected.
The starting position may be a central office, equipment room, outdoor cabinet, existing distribution point, or another approved access location. The final positions may include individual homes, apartments, commercial units, wall outlets, subscriber terminal boxes, or ONT installation points.
The service area should be reviewed together with the expected number of subscriber premises, current activation requirements, future connection capacity, route length, and the locations available for distribution and maintenance.
Organize the Physical Route into Planning Sections
Dividing the route into feeder, distribution, and drop sections helps clarify the function of each cable segment and the equipment required between them.
| Planning Section | Primary Role | Information to Confirm |
|---|---|---|
| Feeder section | Carries fibers from the operator-side access point toward the main distribution or splitting location. | Route length, required fiber capacity, available duct or aerial pathway, reserve fibers, cable protection, and termination position. |
| Distribution section | Extends fibers from the main distribution point toward streets, buildings, floors, or groups of subscriber premises. | Branch locations, distribution box or closure positions, indoor and outdoor transitions, cable structure, maintenance access, and expansion capacity. |
| Drop section | Provides the final optical cable route from a local distribution point to an individual subscriber location. | Drop length, aerial or duct route, facade or riser installation, bending conditions, termination method, connector interface, and environmental exposure. |
| Subscriber termination | Provides the final connection at the home, apartment, office, wall outlet, terminal box, or ONT position. | Mounting location, interface, available space, patch cord requirement, protection, service access, and identification method. |
Match the Architecture to the Deployment Environment
New Residential Developments
A new development may allow ducts, handholes, distribution cabinets, building entry points, risers, and subscriber pathways to be planned before installation. This makes it possible to coordinate the optical route with civil construction and reserve suitable positions for future subscriber activation.
The review should consider construction phases, subscriber density, reserve capacity, cabinet or closure locations, distribution boundaries, expected drop lengths, and how the network will be accessed for maintenance.
Existing Multi-Dwelling Buildings
An existing apartment or mixed-use building may have limited riser space, occupied telecom rooms, restricted access, and existing electrical or communication services. The optical route may need to pass through a building entry point, basement, equipment room, vertical riser, floor distribution position, corridor, and final apartment outlet.
The architecture should identify where outdoor cable changes to an appropriate building cable, where fibers are distributed between floors, and how drop cables can be installed without obstructing existing services. Applicable building and fire requirements must be confirmed for the project location.
Aerial and Low-Density Areas
Aerial deployment may be practical where underground pathways are unavailable or uneconomical. Pole locations, span conditions, branch positions, cable loading, weather exposure, closure access, and subscriber drop distances can all affect the physical architecture.
The route should be reviewed as a complete system. Selecting cable only by fiber count does not confirm whether its construction is suitable for the intended span, support method, environment, or installation practice.
Existing Network Expansion
An expansion or retrofit project may reuse an existing feeder, cabinet, splice closure, splitter position, or building distribution system. Before adding new products, the available ports, spare fibers, enclosure space, connector interfaces, cable markings, and existing route records should be checked.
Clear photographs, route drawings, cabinet layouts, splice records, cable labels, and equipment information can help determine whether the project is a straightforward extension or requires a wider network modification.
Place Distribution Points Where They Can Be Operated
A distribution point is not only a convenient place to divide fibers. It must also support installation, identification, testing, subscriber activation, fault isolation, and future maintenance.
Cabinets, closures, terminal boxes, and floor distribution products should be positioned where technicians can access them without creating unnecessary route length or disturbing subscriber premises. The position should also provide sufficient space for cable entry, bending, splicing, connectors, splitters, labeling, and future additions.
Outdoor positions require suitable environmental protection. Indoor positions should be reviewed for mounting space, pathway access, cable transitions, and applicable building conditions.
Connect the Architecture to the Required Product Families
Once the physical route has been divided into clear network sections, the required product families become easier to identify. Depending on the project, these may include:
- Outdoor or indoor feeder and distribution fiber optic cables
- Aerial, duct, building entry, riser, or protected indoor cable structures
- Splice closures, distribution cabinets, terminal boxes, and floor distribution products
- PLC splitters and compatible trays, modules, cassettes, or enclosures
- FTTH drop cables for aerial, duct, facade, corridor, riser, or indoor routes
- Fiber pigtails, adapters, connectors, patch cords, subscriber outlets, and terminal boxes
- Pre-terminated or project-specific assemblies where repeatable lengths and interfaces are required
Not every project requires every product group. Each product should correspond to a defined position and function within the confirmed network path.
Information Needed to Review the Distribution Path
The following information can provide a useful starting point:
- Service area, premise type, and estimated subscriber quantity
- Starting access point and final subscriber or ONT positions
- Available duct, pole, facade, riser, corridor, or indoor pathways
- Approximate feeder, distribution, branch, and drop route lengths
- Required fiber type, fiber count, capacity, and known interfaces
- Proposed cabinet, closure, terminal box, and splitter locations
- Existing network equipment, cable markings, spare fibers, or available ports
- Drawings, route maps, photographs, reference products, or samples
- Quantity, labeling, testing, documentation, packing, and delivery requirements
The final architecture, optical performance, installation method, and product configuration should follow the approved network design and applicable project requirements. A product catalogue alone cannot define the complete FTTH distribution path.
