What is fibre?
Fibre broadband, also known as fibre-optic broadband, takes its name from the type of cables used to transmit the broadband signal.
Fibre optic cables are composed of thin strands of glass or plastic and use light signals to carry data over long distances at high speeds. They are usually buried underground or laid under the sea. They deliver high-speed broadband internet directly to individual buildings, which can be stand-alone houses, apartment complexes, or businesses.
Why connection via fibre is more prevalent than satellites today
Before the increase of satellites that could deliver the internet directly to individual customers, satellite capacity was very limited, making it expensive.
For what you could pay on a satellite link, for a sizable amount of traffic, you would gain five times as much capacity on a submarine cable because these are huge cable systems carrying a lot of traffic.
Before the advent of fibre internet in Kenya, people used to pay in excess of $4,000, $5,000, or even $6,000 for a service that was 2 MBPs on international satellite connectivity.
How fibre gets to Kenya
The East Africa Marine System (Teams) cable was the first cable to land in Kenya, in Mombasa, in 2009. It is connected to the cable landing system, a government installation at Nyali.
The Government of Kenya and many other operators had a stake in TEAMs, which connected to another cable in Fujairah, a port in the United Arab Emirates.
Fujairah is an international business-to-business (B2B) facility where many other cable stations land and connect to others either through the Red Sea into Europe, France to Europe, or east to Singapore and across the world.
The cables connecting to other parts of the world offer Internet Protocol (IP) )transit services. Internet Protocol runs the Internet, determining how each machine connected to the Internet can communicate.
Every device that connects to the Internet has an IP address, which is public and can be routed over the Internet. IP transit providers are big carriers that aggregate a lot of traffic. Good examples are Tata, the Indian conglomerate, and Level Three, an American company. Internet providers have contracts with IP transit providers to carry their traffic to the Internet.
Every internet provider’s traffic has an administrative domain, a number that is tagged to all its traffic as it creates the connections via IP.
How fibre gets to the home
After the cable landing system in Nyali, the fibre optic cable is connected to a Point of Presence (POP), which is basically a facility owned by the internet provider. Safaricom has a POP in Mombasa that is linked to POPs in Nairobi, which then distribute connectivity onto their own network. Each POP hosts a lot of equipment, such as servers and network elements.
Safaricom’s fibre has multiple levels of redundancy to connect to the cable landing system, so if one leg is affected, traffic can still be carried on the other.
Any fibre connection is essentially a physical connection between the connection at home or the business to a POP, also known as a Central Office.
The fibre cable from the home or business premise to the POP is through a succession of intermediate elements.
From the POP, the cable connects to the Optical Line Terminal and then to several Fibre Distribution Terminals (FDTs). FDTs are the large, beige-coloured boxes you might see at street corners in the estate, often with the sales personnel’s numbers scribbled on them. An FDT in your neighbourhood means that home fibre is in the vicinity.
FDTs connect to Fibre Access Terminal Boxes (FATs), which connect to the device now placed within the home/business through an access terminal box (ATB) and onto the Optical Network Terminal (ONT), a gateway router.
The ONT allows access to the Internet by either a physical cable or wirelessly through Wi-Fi to the home or business devices (phones, TVs, set-top-boxes, laptops, game stations, etc. The ONT enables access to the internet by converting light fibre network signals into copper and electric (Ethernet wiring) for use by routers.
How homes are connected to fibre, or not
Before you are connected, a team surveys your area to determine the number of homes or businesses to be covered. These numbers are usually presented as the number of homes or businesses passed upon completion of the rollout.
Opportunities normally present the team at Safaricom with two scenarios: deployment for single-tenant dwelling units (SDUs) or multi-tenant dwelling units (MDUs), essentially single-family units or apartment blocks. Several commercial considerations are also made concerning the target area to create a sustainable business.
In situations where homes or office blocks are built much later after Safaricom has rolled out its network, the team considers two considerations. If the installed feeder cable has capacity out of provisions made during the prospecting, survey, and design phase, it is possible to connect the additional homes or businesses. Should that not be the case, they then execute mechanisms to provide additional capacity via expansion programs purposely designed on a case-by-case basis.
After planning, the construction phase is very visible as it entails excavations (diggings) to bury the fibre optic feeder cable in underground deployment. Underground fibre optic cables are used for installation beneath the earth’s surface at a specified depth. Normally, a duct (pipe) is buried, and fibre is installed inside the pipe. For overhead deployment, the feeder cable is strung on power poles for rapid deployment.
The size of the number of cores, which are individual strands of fibre in the feeder cable, is determined by the number of homes or businesses to be connected, taking into consideration split ratios.
How fibre contributes to fast internet on mobile phone
Base Transmission Stations (BTS), otherwise known as masts or boosters, are connected using fibre optic cables. These are connected to POPs, which are all connected. That way, when a user tries to access the internet on their phone or other handheld device, the signal is transmitted via the nearest BTS into the fibre optic network.
How fibre cuts happen
Because the fibre optic cables are buried underground or laid on the seabed, they are at risk of damage by various sources.
Causes of fibre cuts include:
- Construction Activities: Workers might inadvertently sever cables while digging for other infrastructure projects.
- Natural Disasters: Events such as earthquakes, floods, or landslides can damage underground fibre optic cables, disrupting internet services.
- Animal Activity: In some cases, animals such as rodents can chew through cables, causing breaks in the fibre network.
- Vandalism: Intentional acts of vandalism can also lead to fibre cuts, though this is less common.
When a fibre cut occurs, it results in a complete disruption of internet services in the affected area. The damage to the physical infrastructure means that data cannot flow through the severed cables, leading to an immediate and often extensive loss of connectivity. Repairing a fibre cut involves locating the exact point of damage, excavating the area, and splicing or replacing the damaged cables.
