Broadband Dictionary

Universal Service Obligation (USO)

A Universal Service Obligation (USO) 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, prior to the Digital Economy Bill 2017 passing onto the statute books the USO for Internet access was 0.028 Mbps (28 Kbps i.e. telephone support for a dial-up modem).

As of May 2017 there are many ideas for how the USO may work, but with a law enabling Ofcom to implement a USO has been passed and now we need Government, regulators and industry to arrive at a consensus and determine how the service will be both delivered and funded.

The USO will initially be delivered in a form where those who currently get below 10 Mbps can request a minimum 10 Mbps speed connection, costs and service choices are yet to be determined. BT has outlined a proposal where the USO would comprise 10 Mbps minimum download speeds and 1 Mbps minimum upload speeds, with all but 0.3% of the UK covered by a fixed line service that meets that target.

Universal Service Commitment (USC)

The Universal Service Commitment was an ambition to ensure that every premise in the UK had access to a minimum connection speed of 2 Mbps and was part of the BDUK superfast roll-outs.

The USC is delivered by application for a voucher which can be used to subsidise the installation of various services, with satellite broadband available throughout the UK (apart from those without site of the southern sky, e.g. cannot also receive Sky satellite TV), fixed wireless services and increasingly 4G via a router you plug in at home and with better antenna than most mobile phones gives a lot of people access to basic broadband.

Digital Britain

The term 'Digital Britain' originates from the Digital Britain Report undertaken by Lord Carter in 2009. It looked at how Britain should go forward shaping its digital services and economy such as broadband over the coming years. Even though it is many years old it is still a significant piece of work that has shaped almost ten years of broadband progress in the UK.


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.

Many broadband services are advertised as 'fibre' but are in reality a partial fibre service, i.e. they feature more fibre than old dial-up and ADSL services but still full short of a true fibre entering your home. The phrase full fibre is often used to refer to services where you have a thin piece of fibre delivering the service.

Fibre-To-The-Home (FTTH) or Full Fibre

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.

Often referred to as full fibre. In the UK the term also encompasses fibre to the building (FTTB) where in apartment blocks a fibre is ran to a comms cupboard on each floor and Gigabit Ethernet cable is then run to each apartment.

Fibre-To-The-Cabinet (FTTC)

Fibre to the cabinet 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. The signal over the copper cable is delivered by VDSL2 generally. 

Virgin Media with its cable broadband network can be called FTTC too, but its more accurate notation if fibre to the node (FTTN), since the final cabinet before a property is not connected by fibre but by coax a larger parent cabinet in the neighbourhood will run several child cabinets feeding them via coax cable.

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.

New variants of the standard are in trial, so the next few years may see Long Reach VDSL2 that has a greater reach.


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.

High Speed or Fast Broadband

There is no firm definition but generally those using one of these two terms mean a connection offering 10 or 15 Mbps type download speeds.


Two main definitions exist:

  • Broadband with download speeds over 24 Mbps. This definition means that ADSL2+ can NEVER count as superfast. This definition is the one that was defined by the Government as part of the original BDUK process.
  • Broadband with download speeds at 30 Mbps or faster. This is the EU definition and is used by any broadband projects that have significant EU funding. We generally use the 30 Mbps definition when referring to superfast coverage.


The term generally refers to broadband that connects at 100 Mbps and faster and as the definition is based on speed it is technology neutral so, DOCSIS, full fibre or any other technology can be considered ultrafast.

This means that most Virgin Media cable products are already ultrafast, the exception is those electing to buy the entry level 50 Mbps product which was re-introduced in the middle of 2017 to give a budget entry level service.

Ofcom the UK regulator uses a definition of 300 Mbps, which is at odds with the UK Government, industry and the EU.


Gigabit refers to broadband with a connection of 1000 Mbps, this is generally a full fibre connection but the latest DOCSIS 3.1 services can offer this sort of connection speed over a coax/fibre hybrid network.

Not all Gigabit services are symmetric but a good number are, and this means you can upload data to the Internet (e.g. post videos to social video) at speeds of 1000 Mbps and also download data at 1000 Mbps.

To give an idea of how fast 1000 Mbps, a HD 90 minute film should fully download in 27 seconds.


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 provide 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, thus keeping the distance between unit and property to 50 to 100m. Openreach is opting to deploy larger nodes attached to its green street cabinets supporting up to 96 lines, this should mean that those living within a cable distance of 500m of a enabled cabinet will enjoy a minimum speed of 100 Mbps if they upgrade and those within 100m are likely to see 500 Mbps download speeds.

The Openreach roll-out is based around the amendment 2 specification and uses up to 106 MHz in the frequency spectrum, the next version amendment 3 will double the frequency used to 212 MHz and mean Gigabit speeds could be achievable on lines of 100 to 150m.


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.

Vectoring is not in use on all Openreach VDSL2 cabinets due to variations in the hardware and the additional costs, but it is referred to as being used tactically, i.e. in areas where the fractional cost will pull a lot of people from just below superfast speeds into the superfast region it may be implemented.


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 to get G.INP working in both downstream and upstream directions.

Error correction has always been supported by Openreach FTTC, but the G.INP system will mean less loss of download speeds and should mean lower latency, as error correction via interleaving can mean FTTC has worse latency than ADSL2+. Compared to interleaving error correction people report G.INP can give a 5 to 10 Mbps boost.

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 £200 to £300 region providing a 300 Mbps download and 30 Mbps upload service. The service is only available via a handful of providers due to the high costs and the three year contract is a hurdle as Ofcom requires the longest consumer contract to be 24 months.

Changes due in January 2018 should see the 36 month contract reduced to 12 months and the monthly pricing line up with the native GEA-FTTP products, but the downside is likely to be a much higher build charge, i.e. over a three year period the price is likely to be similar. Changes to how other premises will benefit mean that if you are a lone property the cost may go up, but if others stand to benefit the new system may be lower for the person who orders, and others on the same fibre manifold will not have to pay any FoD charges but would just see native GEA-FTTP available to order.

Fibre to the drop point (FTTdp)

Internationally FTTdp is mainly talking about, but in the UK the story is a little more complex.

For those not aware the drop point is generally that last chamber in the pavement before a dozen or so premises, or if you have overhead cabling the final telephone pole before your home. This last pole rule is not hard and fast as in some rural areas individual premises may have several poles between them and the DP.

The classical deployment would installs weather proof box on the pole or in the ground and it would be small serving just 16 lines with a fibre feed bringing a 1 Gbps or faster connection to the box, power would come from either a mains feed, down existing copper wires or even customers powering it using a system known as reverse power. This is how is deployed abroad and was trialled by Openreach in the UK, but due to the lower costs and ability to roll-out quickly the Pod based deployment is taking place i.e. power and fibre already at the location and in urban areas will mean almost everyone on a cabinet will gain an ultrafast option. This pod based roll-out is set to reach ten million premises by 2020 but there is nothing stopping Openreach deploying pods deeper into the network e.g. at the DP or maybe another location that is served by several DP.

FTTdp with its 'Fibre to the' is of course technology agnostic for what happens after the DP, so a decade ago we would have been talking about ADSL2+ services being deployed, and in the last couple of years the term FTTrN (fibre to the remote node) has been coined by Openreach when they deploy VDSL2 units that look identical to the weatherproof units. The most common locations for these are thought to be North Yorkshire and Northern Ireland and as they fit neatly onto an existing pole avoid some of the costs a full cabinet would require.

FTTdp has an increasing importance since 5G mobile services to get the much vaunted Gigabit speeds will need to deployed very densely so small 5G nano cells that fit onto existing telephone poles and utilise a fibre backhaul are likely to figure. Other street furniture that is not a DP will also feature in the 5G mobile roll-out e.g. lamp posts which are already seeing Wi-Fi added to them are likely to also be the first 5G locations, thus the competition amongst broadband operators to get contracts for public Wi-Fi across city centres even when there is no money to be made from the Wi-Fi.