The increasing need for high speed internet connectivity and seamless data flow is driving the demand for fibre networks. In India, this demand is being further propelled by the government’s Digital India campaign, which includes initiatives such as BharatNet and the Smart Cities Mission. The government has set a goal of laying an additional 3 million route km of OFC as part of the National Broadband Mission. The Smart Cities Mission has also generated significant opportunities for the industry as OFC plays a critical role in enabling services such as Wi-Fi, video surveillance and security, smart lighting, smart parking and smart traffic management.
The growing proliferation of fibre-to-the-x (FTTx) networks is another factor contributing to the surge in OFC demand. Through FTTx, operators can deliver services directly to the end-user locations from the switching equipment, thereby avoiding connectivity issues at the last mile. In order to ensure optimal service quality in the FTTx network architecture, it is crucial that service providers choose the right network topology and have enough troubleshooting mechanisms in place to locate, identify and resolve issues in the shortest time possible.
tele.net takes a look at the available network topologies to deploy FTTx networks, various business models for operators and the need for fibre network testing…
FTTx network topologies
Telecom operators can now choose from a range of FTTx network architectures to deploy their fibre networks. One of the most widely adopted frameworks is fibre-to-the-home (FTTH), in which the fibre connection is laid up to the customer’s house to ensure maximum bandwidth. However, FTTH is quite expensive to roll out, especially when replacing an existing copper-based architecture with fibre. Therefore, FTTH is typically preferred only in greenfield projects.
Another network topology is fibre-to-the-antenna (FTTA) in which optical fibre is used to connect the remote radio head to the base station in new antennas, or retrofitted in the existing ones, to replace all or part of the coax local loop. OFCs are lighter than coax cables, and therefore easier to install. FTTA ensures low latency, provides high speed backhaul and increases traffic bandwidth.
The FTTB framework provides an alternative to FTTH and FTTA. In this framework, the service provider lays the OFC up to the boundary of the building, such as the basement in a multi-dwelling unit, while the final connection to individual premises is made through other means. Further, each subscriber’s optical network terminal is connected to a fibre distribution hub (FDH) through fibre distribution terminals. The FDH cabinet, which contains splitters, patch panels and fibre management elements, is connected to the central office.
There is another architecture called “fibre-to-the-curb”, in which fibre is laid from a central office to a curb-side distribution point, such as in a pole or an enclosure, on the customer premises. The curb-side distribution point is connected to subscribers through twisted pair copper cables. FTTA can be used to deliver services to a smaller cluster of customers.
Fibre-to-the-node (FTTN) is a cost-effective way of delivering telecommunication services to a large number of consumers from a single node, without the need to roll out the fibre all the way. In an FTTN topology, the optical fibre terminates at a street cabinet, and final connections are made through existing legacy copper or coaxial cables.
Business models
While FTTx remains a promising growth strategy for operators, the viability of the standalone FTTx model remains uncertain as it requires large-scale investments and low revenue realisations. Therefore, operators can explore alternative business models such as build-your-own-infrastructure, build-operate-transfer (BOT), fibre grid and fibre network convergence to provide telecom services through fibre networks.
The build-your-own-infrastructure model lets cable and network operators build their own infrastructure and lease the capacities to users/operators. The infrastructure could be in the form of an outright duct or a dark fibre lease to operators on an indefeasible right-of-use basis.
The BOT model, an alternative to the traditional capex model, allows a specialist to build and manage capacities, and decide on revenue sharing based on a per byte bandwidth delivered, or per-home connect. Meanwhile, the fibre grid model involves aggregating the fibre assets of all owners to build a one-stop shop for dark fibre on a pan-Indian basis. These owners can collectively operate and maintain the entire pool of fibre assets and drive planned expansions. In the case of fibre network convergence, multiple services are combined within a single access network. A single OFC pipe can be used to deliver various communication services such as a distributed antenna system, small cells and Wi-Fi.
Testing of FTTx networks
Mobile network operators have come up with different strategies for designing, testing and deploying OFC. The ideal approach would be the one that helps gain a competitive advantage in the emerging digital market with cutting-edge services that cause minimal interruption.
When it comes to planning and designing a network, the primary focus is to create a sustainable business case for all fibre deployment while utilising available resources. After selecting the appropriate network design, operators must identify the most efficient methods for deploying these networks and connecting subscribers, whether in a single-family or multitenant building. Once the network is constructed, operators must test its quality, extend fibre roll-out services to meet the demands of new and existing customers and meet revenue expectations from the connections.
Fibre installation techniques
There are various methods of fibre deployment, where cable installation is heavily influenced by the development level of the area, environment, population density and business operations. There are primarily three techniques for installing OFCs – aerial, underground and submarine installation.
Aerial installation includes the deployment of cables on pylons or utility poles. These cables carry the risk of continual tension caused by wind, temperature changes and the weight of ice in cold regions. Special installation techniques are used for this type of installation as most OFCs are not strong enough to withstand these forces.
Another way to install OFCs is by installing them underground. This method is particularly useful in urban areas for cross-country cabling. The OFC is installed at a specific depth underneath the earth’s surface. This can be done either by burying it directly in the ground or placing the fibre cable in a duct buried underground. OFCs that are directly buried usually have multiple layers of metallic-banded sheathing to tolerate heat, conductivity, and moisture and soil acidity. Installation through ducts is mostly seen in highly urbanised areas. It involves digging where the OFCs are to be placed in installed ducts. The cables are pulled in the conduit, which is buried underground to a depth of three to four feet. Then, they are placed in plastic pipes pre-installed with inner ducts. These ducts protect the cables and make fibre cable expansion easier.
In submarine fibre deployment, submarine cables are used for fibre deployment under the sea. They carry signals between different stations along the seabed. They are considered to be more reliable than satellite and are greater in capacity. Approximately 95 per cent of all the international data between continents and islands is transmitted using these cables.
Conclusion
Given the increasing importance of high speed internet connectivity, the efficient deployment and management of infrastructure have become critical for delivering proficient services. Moreover, FTTx has emerged as an alternative growth strategy for operators to diversify their revenue streams by bundling FTTx services with service and content offerings. However, FTTx deployments are highly capital intensive, making it crucial for operators to choose the right network topology. Regular testing of FTTx networks is also necessary to reduce the costs associated with product malfunctions, repairs, replacements, product callbacks and repeat production. This ensures better network coverage, superior data performance and maximum uptime for consumers. S
