UK TELECOM GLOSSARY

Fourth generation mobile network. Long-Term Evolution standard. Current mainstream mobile data technology. Sufficient for HD streaming and most daily tasks on all UK networks.

5G Non-Standalone. Uses existing 4G LTE core network as anchor while adding 5G for data capacity and speed. How all UK operators initially launched 5G — faster to deploy than SA.

5G Standalone. A fully native 5G core network without 4G anchor dependency. Enables network slicing and ultra-low latency. Being progressively deployed by UK operators.

Alternative Dispute Resolution. Ofcom-approved schemes resolving consumer complaints against telecoms providers. The two UK telecoms ADR schemes are Ombudsman Services: Communications and CISAS. Free for consumers.

Asymmetric Digital Subscriber Line. Broadband over copper telephone lines. Slowest residential option. Speed degrades with distance from exchange. Being phased out as fibre expands.

Technology combining multiple frequency bands simultaneously to deliver higher data speeds. A key technique for achieving top 4G and 5G performance on supported devices.

Communications and Internet Services Adjudication Scheme. One of two Ofcom-approved ADR schemes for UK telecoms disputes. Free for consumers after exhausting provider complaints process.

Embedded SIM. A digital SIM built into your device, programmable electronically without a physical card swap. Supported by all four UK MNOs and many MVNOs. Enables dual-SIM on single-slot devices.

Fibre to the Cabinet. Fibre optic cable runs to a street cabinet; copper wire from cabinet to premises. Most common UK "superfast fibre" product. Speed reduces with distance from cabinet.

Fibre to the Premises. Full fibre optic connection all the way from exchange directly to your home. Fastest and most reliable residential broadband. Government expansion target for UK.

Three UK's international roaming programme. Post-Brexit terms changed — always verify current destinations, data caps, and charges directly with Three before any international travel.

International Mobile Equipment Identity. A unique 15-digit number identifying every mobile device. Found by dialling *#06#. Used to block stolen phones on UK networks.

Long-Term Evolution. The technical standard underpinning 4G mobile networks. Your phone displays LTE or 4G when connected to this standard.

Millimetre Wave. Very high frequency 5G spectrum above 24GHz. Extremely fast speeds but very limited range (under 200m) and poor building penetration. Limited UK deployment currently.

Mobile Network Operator. A company that owns and operates its own physical mobile network infrastructure. The four UK MNOs are EE, O2, Three, and Vodafone.

Mobile Virtual Network Operator. A company providing mobile services using an MNO's infrastructure under a wholesale agreement. Examples: Tesco Mobile (O2), BT Mobile (EE), Sky Mobile (O2), giffgaff (O2).

Network Authorisation Code. Used when switching provider without taking your existing number to the new network. Text "NAC" to 65075 to receive yours.

Office of Communications. The UK's independent communications regulator. Regulates TV, radio, telecoms, and postal services. Sets consumer protections. Visit ofcom.org.uk for regulatory guidance.

Optical Network Terminal. The device installed at your premises to terminate a full fibre (FTTP) broadband connection. A small box connecting external fibre to your home router.

Wholesale infrastructure subsidiary of BT Group that owns and maintains most of the UK's telephone and broadband network. Multiple ISPs use Openreach's network to provide services to consumers.

Porting Authorisation Code. Text "PAC" to 65075 to receive yours. Used to transfer your mobile number to a new provider. Provider must supply immediately, free of charge. Valid 30 days.

Pay As You Go. A mobile service model where you top up credit and pay only for what you use, without any monthly contract commitment. Available from all major UK operators.

Sky Mobile's data rollover feature allowing unused monthly data to be carried forward and stored for future use rather than expiring at month end. A unique differentiator for Sky Mobile.

Using your UK mobile network service outside the UK. Post-Brexit, UK operators are no longer required to provide free EU roaming — each now has its own paid roaming policy.

The range of radio frequencies used for wireless communication. Ofcom auctions spectrum licences to UK operators. Different frequencies have different coverage range and speed characteristics.

Shared Rural Network. UK Government programme where EE, O2, Three, and Vodafone share rural infrastructure to extend 4G coverage to 95% of UK's geographic area, reducing rural not-spots.

Service Termination Authorisation Code. Text "STAC" to 75075. Used when leaving a provider without porting your number. Account terminates within 30 days of providing the code.

Using your mobile phone as a WiFi hotspot to share its mobile data connection with other devices such as laptops or tablets. Most mainstream UK plans include tethering — verify your specific plan.

Virgin Media O2. The joint venture formed in 2021 merging Virgin Media (broadband and cable TV) with O2 (mobile). Combining UK's largest cable network with a major mobile MNO.

Voice over LTE. Making calls over the 4G data network rather than older 2G/3G voice channels. Provides better call quality (HD voice) and faster connection. Supported by all four UK MNOs.

Making and receiving calls over a WiFi internet connection rather than the mobile network. Useful where indoor mobile signal is poor. Supported by EE, O2, Three, Vodafone, and BT Mobile on compatible devices.