When we talk about fibre rollout, what we are essentially talking about is connecting to the internet via optical fibre. Unlike the usual copper to transmit data, in optical fibre, a beam of light is sent through the optical fibre glass cables, allowing data to travel at the speed of light and inside optical fibre wires that are thinner than a tenth of a human hair. Fibre broadband is capable of delivering internet speeds of over a gigabit per second, making it the fastest medium for the internet.
When it comes to connecting to optical fibre cables at your office or home, there are various types of fibre connections that your Internet Service Provider (ISP) can use, depending on the quality of the connection.
Each of these is denoted as "Fibre to the X", where X refers to where the connection will end.
Once this fibre network reaches your premise, you can access it through fibre WiFi to wirelessly connect to the fibre internet or through a more traditional LAN network. Fibre internet is known to the fastest and provides the best home fibre broadband.
The UK will get access to full fibre rollout through the country's Project Gigabit that aims to deliver gigabit connectivity through fibre coverage to over 85% of the nation by 2025.
About 40% of homes and businesses can already access gigabit internet through fibre or fibre internet, allowing them to leverage high-speed connectivity to conduct personal and professional tasks.
Several cities have already been connected through fibre to the premises in the UK, including Durham, South Tyneside & Tees Valley and areas of Northumberland – including Darlington, Stockton, Hartlepool, Middlesbrough, Redcar and Cleveland, Sunderland, Gateshead and South Tyneside; West Cumbria including in the Lake District National Park, North and West Northumberland and East Cumbria – including Brampton and Rothbury; Cambridgeshire and adjacent areas – including Peterborough and parts of Northamptonshire, Essex, Hertfordshire and Rutland; East Cornwall – including Launceston, Callington and Looe; and West Cornwall – including in Cambourne-Pool-Redruth and Penzance and the Isles of Scilly.
Several operators are working on the rollout of fibre broadband in the UK. These include British Telecom's subsidiary Openreach, Virgin Media, Cityfibre and Gigaclear.
Out of these, Openreach fibre rollout is the largest fibre broadband initiative in the country. The company also offers services via several smaller ISPs. Openreach has recently awarded a contract to STL to provide optical cable solutions for the Full Fibre broadband network. STL will provide optical fibre cable over the next three years to support Openreach’s full fibre broadband network.
Backhaul is the connection from a base station or cell tower to the internet. Fibre Backhaul uses fibre to make this connection. Fibre backhaul involves the physical installation of the fibre, which can be in the ground, strung on utility poles or by any other means to connect the base station to the internet.
All Dielectric Self Supporting or ADSS cables are a type of cable that is suited for fibre deployment in rural areas or for setting up long-distance links between cities. In addition, these kinds of cables are metal-free and do not suffer any bonding or grounding effects. This means that they are economical since they can be installed in existing power lines.
ADSS cables are developed using Aramid yarn, which has a high strength to weight ratio and strong fabric integrity. Aramid yarn ensures that the cable sag remains within limits even during the summer months. They can be placed on existing aerial support structures or new structures for unsupported spans of up to 1000 metres in length.
Below are the major differences between aerial and underground cable deployment.
Aerial Deployment: This type of fibre deployment is appropriate for rural and difficult-to-reach areas where the traditional underground installation is neither possible nor cost-effective. The aerial fibre deployment is typically used to provide broadband in mountains and rugged terrains. It is also ideal for temporary applications or when high-speed fibre broadband needs to be set up quickly. Aerial optical cables are available in several designs to suit different applications. The aerial deployments are affected by environmental factors like a storm. Temperature variations can also lead the cable to expand or contract.
Underground Deployment: The most significant advantage of such a fibre deployment is that the cable is protected from harsh climate conditions. However, installing underground fibre is expensive and time-consuming and requires Right of Way (RoW) permissions from the concerned authorities. In addition, the underground cable can be dangerous if not handled and labelled correctly. The cost of the required equipment and the availability of experts are other challenges associated with this type of fibre rollout.
There are essentially two ways to set up fibre network: Aerial deployment and underground deployment.
Typically, in aerial deployment, the fibre broadband cable is suspended between utility or electricity poles. On the other hand, as part of the underground deployment, fibre cable can be buried directly under the ground or placed into a duct buried in the ground. The cables can also be plowed in or buried in a trench when buried directly in the ground. This is the most common form of fibre network rollout. Underground fibre deployment is more aesthetically appealing when compared with aerial deployments.
Undersea deployment is also considered to be a type of underground deployment. There are more than 400 submarine cables in service across the world. As part of this deployment, the Optical fibre cable is laid under the sea, which enables large amounts of data to be transported at ultra-high speed. So, every time you stream a video or online game, it is first converted to light so it can be transported across the ocean using optical fibre cable. Then, before it reaches its destination, it is converted back to the video. Thus, subsea cables are the foundation of cross-continental online transactions and communications.
There are several techniques used to lay fibres:
Ducting and Trenching: The most common and traditional technique to lay fibre is ducting and trenching. This involves creating a trench by digging or mechanized soil excavation and laying optical fibre in it. Because the fibre is fragile, it needs to be handled delicately. Several things need to be kept in mind while planning fibre deployment, like avoiding bends in the trenches.
Mini Trenches: This method involves creating small trenches and is typically used to lay fibre in sidewalks or roads. This technique is not suitable for sandy soil or soil with gravel. The mini trenches method is generally used for rapid fibre deployment.
Aerial Cables: The most common method is between poles by being bound to a wire rope messenger and tied to a small gauge wire. With lashed cable, the messenger strand component must be properly tensioned to resist the expected loading conditions. This keeps the cable under minimal stress while maintaining the required sag in the messenger and keeping them within the safe specifications limit.
Buried Directly: In this technique, small openings are made on the surface to lay fibres. Though this method is similar to mini trenches, it doesn’t involve any ducting. This method of laying fibre is typically used in laying fibre in urban areas where it is tough to get the Right of Way for ducting.
Horizontal Directional Drilling: In this fibre deployment method, a drilling rig is used to create a shallow arc along a predefined path. This technique ensures minimal impact on the surroundings, and so it is preferred in conditions when trenching or ducting is not possible.
The cost of fibre rollout is massive, making it crucial for the service providers to opt for the right fibre rollout deployment method and to balance between the CAPEX (capital expenditure) and OPEX (operational expenditure). Fibre rollout cost includes the cost of equipment, trenching and fibre cost. Trenching amounts for the major part of the total expenditure for fibre rollout. For this reason, aerial fibre deployment, which doesn’t involve trenching, costs significantly less than underground deployment.