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Broadband Glossary

Universal Service Obligation (USO)

A Universal Service Obligation, or USO for short, is the concept that a provider (or group of providers) should be able to provide a minimum level of service in the coverage area to every resident/business. Traditionally this has meant that BT was required to provide an analogue telephone service to every household in the UK. More recently, it has been the topic of discussion around the Digital Britain Report in 2009 and the need for a USO for broadband, guaranteeing everyone in the UK should be able to receive a minimum level of service.

Digital Britain

The term 'Digital Britain' originates from the Digital Britain Report undertaken by Lord Carter in 2009. It looks at how Britain should go forward shaping its digital services and economy such as broadband over the coming years.


Fibre in broadband refers to the use of fibre-optic cable. This is the use of a glass or plastic tube which is used to send network signals and is often used in replacement of a copper cable. Fibre has the advantage of being easily upgradable by only changing the equipment connected at each end and it allows data to be sent at very high speeds.

Fibre-To-The-Home (FTTH)

Fibre-to-the-home, often called fibre to the premises (FTTP) is a new technology which is used for providing broadband services to homes and offices. It uses fibre-optic cable to deliver high speed broadband services which are often referred to as next-generation services.

Fibre-To-The-Cabinet (FTTC)

Fibre to the cabinet (sometimes called fibre to the kerb (FTTK)) is a technology used to provide high speed broadband services. It involves deploying fibre optic cable to a street side cabinet where the connection will usually continue via a copper cable to your home or office. This technology is used by Virgin Media and BT to deliver their "fibre optic" broadband service. FTTC is often deemed a stop-gap technology between traditional broadband services and full fibre-to-the-home (FTTH).

Next Generation Access (NGA)

Next generation access is a term used to define the new types of broadband services that are currently being developed and deployed. The idea is to provide much larger capacity to users so that they will effectively be able to use it for whatever they want without the service being limited. Current NGA doesn't quite reach this achievement and is made up of both Fibre to the Cabinet (FTTC) technology and Fibre to the Premises (FTTP).

Very High Speed Digital Subscriber Line (VDSL/VDSL2)

VDSL is often used to refer to both VDSL and VDSL2 which are international standards to provide high-speed broadband to homes and offices. VDSL2 (ITU G.993.2) can provide speeds of 100Mbps both downstream and upstream over short distances. VDSL2 is being deployed by BT in road side cabinets as part of the fibre to the cabinet (FTTC) service.


Downstream refers to the direction of Internet traffic which is sent from the Internet to the user.


Upstream refers to the direction of Internet traffic which is sent from the user to the Internet.


Two main definitions exist:


The term generally refers to broadband that connects at 100 Mbps and faster.

This means that Virgin Media up to 100 Mbps and up to 152 Mbps cable products are already ultrafast.


While there is no official definition, the phrase appears often on twitter or in marketing material and we will use the term for connections that have download speed of over 300 Mbps.


While VDSL2 can provider up to 76 Mbps speeds, G.Fast is the next generation of xDSL that uses even higher frequencies to squeeze more data into the copper telephone lines.

Ideally G.Fast is deployed as a small weatherproof unit on the final telephone pole or in a pavement chamber to support 8 to 16 premises.

Openreach is looking at starting to use G.Fast in the next few years but may initially hide the new units in the existing fibre cabinets. This will not benefit everyone on a cabinet, but it will allow Openreach to roll-out an ultra-fast product fairly quickly to around half of UK households.


Vectoring relies on complex mathematics to compensate for the cross-talk (noise) that all the VDSL2 (FTTC) services in a bundle of copper wires generate.

The compensation will reduce the effect of cross-talk that has been seen to lower the speeds the early adopters get on each fibre cabinet.

Vectoring will provide the largest benefits to fairly short lines, i.e. up to 1km but smaller benefits may result for longer lines.


An improved error correction system that Openreach is deploying, around half the fibre cabinets are able to use the new form of error correction, but those based on ECI hardware are awaiting on new software updates to resolve compatibility issues.

Error correction has always been supported by Openreach FTTC, but the G.INP system will mean less lose of download speeds and should mean lower latency, as error correction via interleaving can mean FTTC has worse latency than ADSL2+.

Fibre on Demand (FoD)

Openreach in some areas where FTTC is available will if you are willing to pay a high install fee (£1500+) and agree to a three year contract (long contract makes it more suitable for business use) to install FTTP direct to a building.

The install costs are generally less than a dedicated leased line and the monthly costs are a lot lower in the £150 to £200 region providing a 300 Mbps download and 30 Mbps upload service.

In early 2015 new orders were placed on hold but this is expected to change later in Summer 2015 when a FoD2 version should appear.