Second National Infrastructure Assessment: Baseline Report   |   Call for Evidence

Baseline Report Annex A: Digital

Analysis of the UK's digital infrastructure which informs the Second National Infrastructure Assessment: Baseline Report.

Tagged: Digital & Data

Sector overview

Digital connectivity has become a necessity, with broadband and mobile services linking homes and businesses across the UK.

Demand for data, and therefore the speed, reliability, and capacity of broadband connections, is growing rapidly. Demand will continue to increase as businesses, homes and all types of economic infrastructure become smarter. The Covid 19 pandemic accelerated these trends and reinforced the fact that the provision of fast and reliable digital connectivity is now almost as central to society and the economy as the supply of electricity or water.

Digital infrastructure consists of various interconnected networks which are owned and operated by different companies. Broadly, these networks are split into three different levels:

  • The core network is the backbone of the digital communications networks and is the “intelligent” part of the network, which identifies where the network’s subscribers are and ensures that data is sent to the correct user. It connects an operators’ network directly to the backbone of the internet.
  • The backhaul is the middle of the network and consists mostly of high capacity transmission lines that connect the core network to the local exchanges for fixed broadband or wireless base stations for mobile connections.
  • The access network links directly to an end user’s equipment, such as routers or mobile phones, and connects them to the backhaul network. Access networks for broadband include copper and fibre connections to premises, and for mobile connections, consists of networks of base stations.

Digital infrastructure is a complex and interdependent system of systems, but the infrastructure covered by the Commission focuses on those services that are accessed by consumers and businesses and broadly splits into two categories: fixed broadband and mobile connections.

Fixed broadband connections

Fixed broadband provides a continuous connection to the internet for homes and businesses, replacing previous ‘dial up’ connections. To use home broadband, customers usually connect devices wirelessly to a WiFi router. The router is connected through the wall to broadband cabling technology, which is normally supplied to the premises via a street cabinet. The cabinet in turn connects via more cables to the exchange, which is part of the internet service provider’s network. There are a range of different service levels that fixed broadband can provide (see figure A.1), depending on which access technology is used:

  • Copper (ADSL)1 consists of a copper cable connecting the exchange to the cabinet and the cabinet to the premises. Copper networks are only capable of providing a basic level of connection and can be unreliable. Actual speeds delivered by copper connections diminish with distance.2
  • Fibre to the cabinet consists of a fibre cable connecting the exchange to the cabinet but a copper cable connecting the cabinet to the premises. Fibre to the cabinet can provide superfast connections but, like ADSL connections, is susceptible to faults and actual speeds diminish with distance between the cabinet and the premises.3
  • Hybrid fibre coaxial cable involves connecting the exchange to the cabinet with fibre cable but then connecting the cabinet to the premises with a coaxial cable, which is a form of copper based cabling.4 The latest standard of cable technology — DOCSIS 3.1. — can provide gigabit connections, however in practice the speeds that users receive can be slower5

Full fibre to the premises consists of a fibre connection from the exchange all the way to the premises, normally bypassing the cabinet. It can provide gigabit connections and can be more reliable than the other technologies.6 Generally, distance to the premises does not affect the speed delivered and localised congestion can more easily be avoided.

Type of serviceMinimum speed (Mbit per second)Example activities that service can support
Decent broadbandAt least 10 (download) and 1 uploadMaking video calls, downloading a one hour episode of high definition television (HDTV) in around 15 minutes
Superfast30 to 300 (download)Capable of supporting multiple devices at once, downloading an episode of HDTV in around four minutes
Ultrafast300 to 1000 (download)Multiple people streaming ultrahigh definition TV at once, downloading an episode of HDTV in less than 30 seconds
Gigabit1000 and above (download)Capable of downloading a high definition film in under one minute or a full 4K film in less than 15 minutes

Mobile data and voice connections

Mobile networks provide telephony and data connectivity services to consumers by using a mobile phone as a terminal. Like fixed broadband, there are a range of different service levels that mobile connections can offer, as shown in figure A.2. Mobile access network infrastructure consists of two main elements:

  • The radio access network: The network of base stations providing cellular coverage across the UK, allowing mobile devices to transmit and receive data via the radio spectrum. Base stations vary in size and cost, but each requires an appropriate site with a power supply and a fibre or microwave connection to the backhaul network.
  • The radio spectrum: Part of the electromagnetic spectrum, and is widely used for modern day telecommunications, broadcast TV and radio. Information can be transmitted over different frequency bands within the radio spectrum. The radio spectrum is a finite resource and so bands are allocated to users, such as the Mobile Network Operators, by Ofcom which has a duty to ensure that the spectrum is efficiently used.
Type of serviceDescription
2GThe oldest available technology deployed in the UK, now mainly used for telephony services
3GThe first generation of service that enabled the use of internet services
4GThe most widely accessed technology, capable of delivering reasonable capacity broadband for video streaming
5GThe latest generation of mobile communication technologies, with the potential to provide ultrareliable, low latency and very high capacity connectivity that can support new use cases across areas such as transport and the industrial Internet of Things

Convergence of fixed and mobile connections

Although broadband is normally provided via a cable it can also be provided wirelessly through a service known as ‘fixed wireless access’. Currently, three of the four Mobile Network Operators offer fixed wireless access, as do many of the Wireless Internet Service providers, who use other radio spectrum bands. Fixed wireless access is offered on 4G and 5G networks, usually to an indoor router. Based on the Mobile Network Operators’ claimed coverage, at least 95 per cent of UK premises have access to a fixed wireless connection, although the vast majority of this is accessed through a 4G rather than 5G device.7 However, due to capacity constraints and localised issues, the quality of this service may be limited.

Fixed wireless access can also be provided by satellites. This is particularly important for premises where no other connection type is available. However, connections provided by geostationary satellites are often poor quality due to the distance between the satellite and the premises it is connecting to.8 Current capacity is also limited, and the cost of supply connections can be high.9 This may change as more low earth satellite constellations are deployed, such as Starlink and Open Web, which are closer to premises and therefore can provide better quality.10

Usage of fixed broadband and mobile connections

Consumption of data has grown dramatically over the past decade, both for fixed and mobile connections. Figure A.3 shows that consumption from fixed connections increased from around 25 gigabits per month in 2012 to around 430 gigabits per month in 2020, while consumption of mobile data increased from 0.25 gigabits per month in 2012 to around 4.5 gigabits per month in 2020. Fixed broadband data consumption is significantly higher, which is partly because most consumers typically use it for data heavy activity such as higher resolution video streaming.

Figure A.3: Data consumption has increased rapidly over the past decade

Annual fixed data consumption per household

Annual mobile data consumption per user

Source: Ofcom (2021), Communications Market Report 2021

Digital infrastructure and the Commission’s remit

The Commission’s remit covers the infrastructure required to deliver telecommunications, primarily focusing on the infrastructure needed to deploy both fixed and mobile connections. In addition, the Commission also considers how the application of digital infrastructure, and the collection and analysis of data, can facilitate more effective delivery of services in the other infrastructure sectors within its remit.

As digital infrastructure policy is a reserved matter, the Commission’s remit covers England, Scotland, Northern Ireland and Wales.

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