Glossary

Broadband speeds are expressed as an amount of data downloaded per second, usually in megabits per second (Mbps).



• Megabits and megabytes: Megabits (Mb) and megabytes (MB) are units for expressing a quantity or amount of data

• Eight megabits (Mb) is equal to one megabyte (MB)

• Eight gigabits is equal to one gigabyte (GB).



Decent broadband

Ofcom defines a “decent” broadband as a connection capable of delivering a download speed of at least ten Mbps and an upload speed of at least one Mbps.136 This is the specification for the Government’s Universal Service Obligation (expected to be available in 2020).



Superfast broadband

Superfast broadband does not have a single definition. The UK Government defines it as speeds greater than 24Mbps, whereas Ofcom and the European Commission define it as speeds greater than 30Mbps. The Scottish and Welsh Governments also use the higher definition.



Ultrafast broadband

Ultrafast broadband does not have a single definition. The UK Government defines it as speeds of 100Mbps and higher, whereas Ofcom defines it as speeds greater than 300Mbps.



Gigabit-capable connection

The UK Government defines a “gigabit capable” connection as one that can support 1 gigabit per second (Gbps) download or upload speeds. One Gbps is equal to 1000 Mbps.

ADSL

ADSL (asymmetric digital subscriber line) technology delivers broadband using copper telephone lines – the connection speed will depend on which type of ADSL is being used; and the quality and length of the line from the telephone exchange to the premises. The further away from the telephone exchange, the slower the connection.



Fibre optic cable

Fibre optic cables are made of glass or plastic. They transmit data using light. Fibre optic cables can transmit more data with faster speeds and significantly less signal loss with distance compared to copper wires. Fibre to the Cabinet (FTTC) Fibre to the Cabinet (FTTC) is the main technology used for superfast broadband roll-out in the UK. FTTC connections use fibre optic cables to carry the signal from the telephone exchange to street cabinets and then existing copper lines are used from the cabinet to premises.



FTTC technology can provide speeds of up to 80 Mbps. However, the maximum speed that a premises can receive reduces the further away it is from a cabinet, with superfast speeds (above 24 Mbps) available up to approximately 1000m from the cabinet.



G-fast

G-fast is a broadband technology being deployed in a pilot commercial roll-out by Openreach. G-fast is a variant of FTTC technology, which allows ultrafast speeds (up to 300 Mbps) to be delivered using the same copper telephone lines that are used in FTTC technology.138 It works by expanding the frequency range over which signals are transmitted, allowing for higher speeds. Higher frequencies slow sharply with distance however so only premises within 350 meters of the cabinet are expected to benefit. G-fast is installed by fitting an ‘extension pod’ onto existing cabinets, and therefore can be installed quickly at low cost.



Cable broadband

All cable broadband in the UK is provided by Virgin Media. Cable networks use a combination of fibre optic cables to street cabinets and high-grade co-axial cables (which are also used for cable TV) from the cabinets to premises. Co-axial cables experience less signal loss over distance compared to copper wires. The latest standard DOCSIS3.One allows for speeds of around one Gbps (1000 Mbps) by cable.



Full-fibre [Fibre to the Premises or Home (FTTP/FTTH)]

Fibre to the Premises (FTTP) or Fibre to the Home (FTTH) is a technology where the fibre optic cable runs all the way to the premises or home. FTTP/FTTH can provide download speeds of one Gbps (1000 Mbps). This is also referred to by the Government as full-fibre.



Fixed wireless

Fixed wireless uses specific frequencies of the radio spectrum to transmit signals through the air in a similar way to mobile phone networks, doing away with wires. Depending on the number of users served by the wireless connection, it is capable of delivering superfast speeds. Most wireless ISPs only offer limited coverage in specific areas, for example rural villages.



Satellite broadband

Satellite broadband is an option for those who live in rural areas where traditional fixedline based broadband services aren’t available. It uses a satellite dish to provide access to broadband services. The main advantage of satellite broadband is that it can be provided virtually anywhere in the world, as long as there is a clear line of sight to the satellite (south for the UK).

Bandwidth

The maximum amount of data that can be transmitted along a channel – similar to the amount of water that can be squeezed through a pipe.



BDUK

Broadband Delivery UK



Contention ratio

The degree to which bandwidth is shared between different end-users at the same network node. When more end-users share the same bandwidth within a network this can lead to a slowdown in performance.



Connection charge

The fee a broadband provider charges customers when it installs a new line to connect their premises to its network, or the fee a broadband provider charges customers when it takes over the fixed broadband line serving their premises. This fee is often waived or reduced if customers also take up certain retail broadband packages with the provider.



Download speed

Also downlink or downstream speed. Rate of data transmission from a network operator’s access node to a customer, typically measured in Megabits per second (Mbps).



DCMS

Department for Digital, Culture, Media and Sport.



Exchange

The local telephone exchange is the building where all consumers’ copper telephone lines are connected to enable telephone calls to be switched, and where network equipment is installed which enables consumers’ data traffic to be routed via an operator’s core network to its destination.



Fixed broadband

Broadband delivered over a fixed line to the customer’s premises.



Latency

The time it takes a single packet of data to travel from a user’s PC to a third-party server and back again. The figure is most commonly measured in milliseconds, and a connection with low latency will feel more responsive for simple tasks like web browsing.



Upload speed

Also uplink or upstream speed. Rate of data transmission from a customer’s connection to a network operator’s access node, typically measured in Megabits per second (Mbps).