UK’s Future Telecoms

Modern telecommunications networks have the potential to enhance communication, deliver economic growth and innovation, transform certain industries and improve quality of life across the globe. Telecom networks underpin all national critical infrastructures, and their security and resilience are crucial to national security.

Future Telecom Technology and Roadmap

Modern telecommunications networks, like 5G, have the potential to enhance communication, deliver economic growth and innovation, transform certain industries, and improve quality of life across the globe. Use cases foresee next-generation networks supporting millions of devices, powering smart cities and underpinning critical functions like power plants and emergency communications. Nonetheless, legacy mobile networks still play a crucial role in the development of modern telecommunications networks. They may support fewer devices and provide fewer critical services, but services such 2G, 3G, 4G and wired services still form part of existing infrastructure, have industry-specific applications, are used by rural communities, and provide back-up should modern systems fail.

Telecommunication networks, like any network, are prone to denial of service attacks. As a crucial part of daily life and a functioning economy, including the support of critical areas such as space, protecting telecommunications networks is a matter of national security. Most recently, a Chinese advanced persistent threat (APT) actor, dubbed Salt Typhoon, was said to have compromised major US telecommunications networks leading to widespread concerns over data and communications security. The group, linked to China’s Ministry of State Security, exploited vulnerabilities in telecommunication infrastructure, including wiretapping mechanisms used by law enforcement. Balancing the growth opportunities of modern telecommunications networks with national security risks is an enduring challenge for governments and societies.

What is Mobile Cellular Systems Technology?

There are many technologies that can be categorised as telecommunications networks – including mobile cellular networks, WiFi, and space satellites. Other examples include HAPSs (High Altitude Platform Stations) which are airborne systems that typically operate 18-25km above earth, UAV (Unmanned Aerial Vehicles) which are drones that can enhance wireless connectivity, and Fixed Wireless Access (FWA) which is typically used at just outside the homes, inside homes or in offices. Finally, undersea fibre or cable networks are laid on the ocean floor to enable the high-speed transmission of data. Recently, there have been high-profile incidents where underseas cables have been damaged either accidentally or via sabotage. Overall, mobile cellular networks (including 5G) are the largest telecommunications network category in terms of global market share, scale and adoption. 6G is expected to be available on the market from 2030 onwards.

What are typical mobile network sub-systems?

▲ Figure 1: A mobile network system architecture

A mobile network is comprised of three sub-systems:

• Core Network is where all system intelligence resides and controls many base stations (on the scale of thousands) in a network. It manages mobility and call forwarding to a user wherever they happen to be, regularly authenticates customers and devices when they want to set up a session, handles charging and billing and manages communications to other networks (such as fixed line network, internet and other mobile operator networks) nationally and internationally. Operation and management sub-system control radio access and core network operation. Core Network connects all these functions and databases using many switches and routers, which are interconnected usually with a network of fibre/cables. Core Network can be housed in a cloud or within a physical data centre. The connectivity (when between different boxes and functions) will vary from one generation to another. For operational and upgrade costs savings, mobile operators are gradually moving their Core Networks to a cloud platform.

• Radio Access Network (RAN) consists of Base Station (radio mast), wireless link and user equipment (UE) or mobile phones. Each Base Station (BS) provides service to a limited geographical location which is referred to as a cell. In a mobile network, thousands of cells are needed for a country-wide coverage.

• Service Platform supports internet services and mobile network operator (MNO) own services.

In a typical mobile network, there are millions of user equipments connected to thousands of Base Stations (BSs). Each generation from 1G to 5G consists of these three sub-systems.

The evolution of mobile cellular systems is shown in Figure 2.

▲ Figure 2: Evolution of mobile cellular systems

Roughly speaking, every ten years a new generation is standardised and deployed.

It is important to note that mobile systems are based on global standards for achieving global roaming using the same device or SIM (Subscriber Identity Module) card anywhere in the world, as well as for reducing the cost thanks to economies of scale.

A SIM card contains all users’ identity and service profiles as well as information about their home network. A home network is the one that a user buys their subscription from.

The development of any generation is broadly divided into three phases, which sometimes overlap in time.

Figure 2 shows evolution of mobile wireless through generations. The following five points are important to note:

1. Each generation is researched, standardised and deployed approximately every 10 years.

2. Each generation is deployed for about 20 years – roughly the span of time in which the capacity is saturated, or a more capable generation is introduced.

3. A new generation does not necessarily replace the previous generation. For example, 2G and 3G are still in operation. 3G can still provide voice services and medium rate data transfer (for example, mid-range speeds that can support lower resolution video streaming and basic household backups). However, as these services can also be provided by 4G and 5G, 3G is expected to be terminated in next few years by Vodafone and BT in the UK and in some other countries. 2G is now mainly used for services like smart metering in the UK.

4. The emergence of each generation is justified by market needs starting with new use cases which also have a clear business case.

5. Every generation goes through new development phases with new capabilities.

Understanding the “Tech” in Telecom

5G as the current global standard: The case for developing 5G emerged in 2015, based on need for higher data rate (10 times faster than 4G) and more capacity following the impressive success of 4G and smartphones. In addition, wireless technology was needed to enable the transformation of other industries to improve their productivity and cost effectiveness through the automation capability offered by 5G, including manufacturing, transportation and utilities. 5G also extended wireless communication for the automation of vertical industries. This automation, also called the Internet of Things (IoT), enables connecting and managing machines and robots (for example: vehicles, UAV, robots and machinery in factories). However, automation requires high wireless fidelity (reliability) and guaranteed low delay (latency) for control of machines (robots) specially for mission and time-critical applications.

These new features of high reliability and low latency make 5G fundamentally different from previous generations. For example, 4G and previous generations were about primarily connecting people to people and connecting people to the internet through smartphones. People are tolerant to delay and delay variation (jitter) but machines are not.

Industrial Application of 5G: The needs of vertical industries are mainly for connecting machines rather than people. While the belief is that 5G will revolutionise other industries and the national economy with its automation capabilities, take up of 5G in industrial setting has been slower than was expected and the expected transformative effects remain to be seen. However, in China Industrial 5G is much more widely adopted compared with the rest of the world. Reasons for slow take up in other countries are due several factors: Mobile Network Operators (MNOs) lack experience in business to business (B2B) model; understanding of mobile ecosystem and evolution by vertical industries; and market scale for equipment vendors. MNOs fully understand the business to consumer (B2C) model which has been the case since 2G. Equipment vendors are used to nation-wide scales whereas for 5G industry use cases the coverage is local and of small scale to be profitable for vendors. Furthermore, governments are still grappling with the process of auctioning of the radio frequencies for local use as opposed to nationwide and exclusive licence use. For nation-wide license of spectrum, each MNO has its own piece of spectrum which makes it easy to manage interference between different networks. Local licensing of spectrum on the other hand raises the problem of co-existence of several networks that use same part of spectrum and can potentially interfere with each other. Interference management for co-existence of private 5G in industrial settings requires knowledge of wireless deployment and optimisation.

In 5G technologies there are effectively three networks: Massive Machine-Type Communications (mMTC), Ultra Reliable and Low Latency Communications (URLLC), and Enhanced Mobile BroadBand (eMBB).

1. Massive Machine-Type Communications (mMTC) 5G offers mass connectivity of devices in the form of IoT for various sensing applications. The target is to support 1 million devices per square km – which is beyond 4G capability. In 5G standards, it is commonly referred to as mMTC.

2. Ultra Reliable and Low Latency Communications (URLLC): It is important to note that the low delay or latency is better defined as guaranteed or deterministic delay. Guaranteed delay means low delay variation (jitter) must be very low. This capability of 5G in standards is referred to as URLLC.

3. Enhanced Mobile BroadBand (eMBB): Another capability offered by 5G is mobile broadband communications – in 2015, the justification was that 4G was going to face a capacity crunch by 2020. There is urgent need for more capacity and higher speed as most applications are based on video and High Definition (HD) video. This aspect is named eMBB. 5G maximum speed is 10 times that of 4G.

The performance requirements of these three networks are extremely conflicting, in terms of data rate, number of users, reliability, latency, security and Quality of Service (QoS). These three networks are supported in one infrastructure using an innovative solution called “network slicing”, where all resources (computing, energy, bandwidth, processing etc.) are dynamically divided (sliced) and each slice carries one type of traffic. The slices do not interfere with each other and all conflicting requirements can be supported using network slicing. Each slice can have its own tailor-made technologies in support of the specific service it carries. There is extensive flexibility to have different security, latency, and data rate QoS mechanisms for each slice.

The choice of frequency in deployment of any standard including 5G is important from many points of view such as capital cost, operational cost, capacity, energy consumption and coverage range. Three frequency bands were identified for 5G called the “pioneer bands”: 700 MHz (cost-effective coverage increase in less densely populated areas); 3.5GHz (for high population density environments); and 26 GHz (for environments with very high population densities such as in airports, sport and music venues). So far, the technology is not mature enough to support 26 GHz. MNOs globally have focused on rolling out 5G at mid-band of 3.5GHz and only mobile broadband (eMBB) service based on a B2C model.

The use case of 6G: Every generation has to bring about new dimension and capabilities to the market and 6G is no exception. In 2023, the ITU Radiocommunication Sector (ITU-R) identified three important use cases for 6G (referred to as IMT 2030): ubiquitous connectivity, AI and communication, and integrated sensing and communication. The research community in industry and academia are working on technology solutions in support of these use cases. In 2025, use cases for 6G will be further discussed in 3GPP and refined in terms of value of these use scenarios and whether they can help reduce the cost as well as bring new revenue to MNOs and improvement to environmental sustainability and people’s quality of life. The standardisation on those selected use cases will start around June/July 2025.

What are the three use cases and why are they important?

1. Ubiquitous Connectivity: universal connectivity is intended to provide broadband communications anywhere. This will hopefully eliminate the problem of patchy coverage. The technical implication of this use case is that the future 6G network will be an Integrated Network of Networks between space (Satellite and UAV/HAPS) or Non-Terrestrial Networks (NTN) with Terrestrial Networks (TN). This integration will make the 6G system a three-dimensional Network (3D Network). In a unified 3D network a user is connected irrespective of the user’s geographical location (including land, sea, air and remote locations).

2. AI and Communication: The incorporation of AI and Machine Learning (ML) in all layers of communications will lead to an intelligent mobile network that can self-manage and self-optimise communications resources (spectrum and energy consumption) and also enable smarter and more personalised services. Future networks will be so complex that today’s management of these networks by people will be untenable. AI should help to reduce network outages and improve its resiliency against intentional and unintentional incidents. It is also expected to reduce operational costs of a network.

3. Integrated Sensing and Communication: The decisive difference between 5G and 6G is the importance of sensing. Sensing is an integral part of 6G, also referred to as “Internet of Senses”. Sensing can capture ambient information to be integrated into communication networks for smarter and personalised services to users as well as for the network to manage itself. Considering how dynamic mobile networks are in terms of users, vehicles and robots’ mobility, their variation in user traffic density as well as radio propagation sensing information helps the network to manage its resources more accurately and in time. Integration of sensing into communications offers other advantages: sensing information can enable new services such as locating objects and people, and their mobility, and thus provide more relevant services. For example, driverless vehicles can detect proximity of objects and other vehicles to avoid possible accidents. The combination of sensing data (information) with AI makes AI a more powerful tool. AI algorithms perform better with more – and more varied – data, which can be continuously provided by sensing.

Intersections with Other Technologies

Developing technologies that meet 6G-use scenario and technical performance requirements demands that technologies and industries which have been traditionally developed or worked in silos come together.

• Space and Terrestrial Systems: Development of 6G will need expertise in both satellite communications, UAV, HAPs, WiFi and cellular mobile systems. Common standards between these sectors are important for unification between them so that a user can roam between sectors without changing their devices. This requires expertise in system engineering for overall energy efficiency, spectrum efficiency, and a resilient and secure 6G. This also applies to the transportation industry for connected vehicles or eventually driverless vehicles.

• IT and Communication Technologies: Communication technologies are gradually adopting IT technologies in the softwarisation of the system. As with the IT industry, upgrading software is easier and quicker without changing expensive underlying hardware. This is referred to as virtualisation and is a common practice in the computer/desktop industry, where applications and software can be changed without changing the computer hardware. This is expected to reduce the capital cost of telecom networks and help with speeding up introduction of new services and functionalities.

• Computer Science, Electronic Engineering and Physics: Different disciplines of computer science and electronic engineering will need to work together in virtualisation of future telecom systems and more specifically combined expertise needed on AI, wireless (signal processing, RF components, and so on), Cloud, security, radio propagation, antenna and Reconfigurable Intelligent Surfaces technology, quantum networking and sensing is essential.

• Biology and Computing: Inspired by the way neurons communicate with each other at extremely low energy, neuromorphic computing and communication is considered important in achieving several orders of magnitude in energy efficiency compared to traditional transmitter and receiver approach.

Relevance of the Technology for National Security

Protecting telecommunications networks is a matter of national security. Four risks to consider are highlighted below:

Risk 1: Supply Chain Risks and Vendor Diversity.

The ecosystem of telecommunications equipment providers is limited. This is further complicated by the exclusion of high-risk vendors (such as Huawei) based on concerns over their links to the Chinese state. The market is limited to Ericsson and Nokia, and to a limited extent, Samsung. These vendors already have difficulties in meeting global demand. There is a risk that vendor-specific vulnerabilities could easily spread across the whole network, which is a considerable risk to supply chain resilience.

To counter this dependency in the UK ecosystem, the Department for Culture, Media and Sport (DCMS) assembled a “supply chain diversification task force” in 2020. The taskforce provided a set of recommendations which are being currently implemented in DSIT. The comprehensive recommendations to address the concentration of 5G suppliers in the UK’s infrastructure market cover:

• Influencing telecoms standards.

• Policy and regulatory measures.

• R&D investment and innovation.

• Identifying opportunities to invest in long-term R&D and innovation to build UK capability.

• Enhancing market transparency.

• Greater international collaboration.

Risk 2: The Dominance of Closed or Proprietary Radio Access Networks (RAN)

Open RAN is a standard for networks which makes them interoperable, meaning that hardware and software can be sourced from multiple vendors. In theory, this infrastructure model reduces the risk of reliance on one supplier in a telecommunications network. In contrast, closed network architecture means that components within a network are provided by one vendor with little flexibility for wider system integration using components from other suppliers. Traditionally, Huawei, Ericsson and Nokia provide both their own software and hardware for RAN in a closed environment. Consequently, OpenRAN initiatives face serious challenges. While creating long-term market diversity is an important aim, it may take a long time to achieve.

DCMS’ supply chain diversification taskforce emphasised a new strategy of “open networking” and more specifically “Open RAN”. It supports an approach where different network functions are disaggregated and connected with open standard interfaces. This open networking paradigm can achieve two important goals:

1. Facilitate the entrance of new players in the ecosystem of vendors with their own niche product.

2. Put an end to black box telecom equipment which could carry insecure and illegitimate codes.

On a global level, the UK strategy of open networking is now being supported by different MNOs and governments. It has mobilised new small and medium size companies as well as IT companies to enter the telecom market.

There are still risks from using Open RAN. An open and disaggregated network might increase the risk of network failure and could be an easier target for network attacks and denial of services. For OpenRAN to succeed, R&D and innovation investment should focus on security, resilience and energy efficiency.

Finally, satellite networks are an important component of 6G that will provide new opportunities for the UK’s satellite industries. A greater prevalence of satellite telecommunications networks may benefit the UK’s strong MNOs community (e.g. Vodafone, EE/BT, Virgin Media O2) while reducing reliance on the traditional group of infrastructure providers.

Risk 3: Sensing Technologies

Sensing technologies should drive improvements in automation, real-time decision-making and the user experience in telecommunications networks. One use case relates to sensing technology and autonomous vehicles which can detect objects, pedestrians or road conditions while leveraging 5G networks. The speed of modern telecommunications like 5G means that sensing technologies work instantaneously.

The national security risks relate to the potential for espionage and vulnerability exploitation. One risk is that sensing technology processes significant amounts of real-time and personal user data. Another risk relates to high-resolution positioning information (below 10 cm accuracy). This technology enables threat actors to locate people and objects with high accuracy. Looking further ahead, as the number of data points increase from sensing technology, it could be used to profile individuals in terms of physical and mental capacities. Finally, as sensing technology is able to scan environments at speed, the impact of the application of this technology in military environments requires further understanding. Sensing of environments is similar to radar and provides more intelligence for operation of civil or military networks.

Risk 4: Artificial Intelligence in Telecommunications Networks.

The use of AI and ML for telecommunications networks is in the early stages of R&D, much like other sectors. Current AI solutions are not reliable for time-critical applications such as self-organising and self-healing networks called here as Self-X. In Self-X networking, a network can detect potential network failures or detect anomaly behaviour in traffic, for example, and tries to correct or heal itself from possible outage with zero human operator intervention. Decision-making on possible network failure or prevention must be accurate and timely. Importantly, the combination of sensing technologies and AI is critical for AI training data, solutions and decision-making. At present, AI solutions and decisions are unexplainable and cannot be trusted in time for mission-critical applications.

Finally, critical national infrastructure (e.g. finance, health, utility services, government) are underpinned by telecommunications infrastructure. The 3D-Network of Terrestrial and Non-Terrestrial Networks is a conceptual framework that integrates various types of communications networks, over land, air and space. In theory, the interoperability of this framework provides greater resilience should one area fail. One risk is that satellite communication networks that use inter-satellite links can easily bypass certain countries. This may be a question of sovereign capability and control over communications which will require a Network Operation Centre for any satellite networks to be located in the UK to mitigate this risk.

Future Developments

Here, future telecom development over the next 10-year horizon is briefly explained:

AI and Sensing: Future telecom starting with 6G will be intelligent, delivering personalised services to overall network management by combining sensing with AI. Current Large Language Models AI and Generative AI mainly use data available on the internet and are suitable for text. Future multi-modal AGI (Artificial General Intelligence) will support voice, text, video and other data. The UK needs to invest in high performance computing facilities and make available relevant data to develop foundational telecom models which are both reliable and explainable.

Mega-constellation of satellite communications: The future roadmap for satellite communications and their future generations, in addition to being based on common standards like terrestrial networks, is progressing from fixed broadband (current systems such as Starlink, EutelsatOneWeb) to users, and in support of connectivity for cellular terrestrial network (such as Rivada ) to mobile broadband directly to vehicles and eventually directly to handheld terminals. Direct to device (vehicles and handheld) will be a game changer for mobile systems and in particular satellite communication systems. This will truly unify NTN and TN into one network. There are also ongoing discussions that satcom networks should be providing Positioning, Navigation and Time (PNT) as well as broadcast services. Provision of high accuracy time in addition to GNSS (Global Navigation Satellite System) is critical for resilience of National Critical Infrastructures that rely on accurate and reliable time information.

Rahim Tafazolli is Regius Professor of Electronic Engineering, Professor of Mobile and Satellite Communications, Founder and Director of 5GIC, 6GIC and ICS (Institute for Communication Systems) at the University of Surrey.