2G & 3G network sunsetting: The future of connectivity

It’s now three years since the UK government confirmed its timeline for the closure of 2G and 3G services, to free up valuable radio spectrum for 5G and future services and ensure the UK remains connected to the latest technology. Since then, a number of operators have switched off their 3G networks and while monitoring closely for our SMETS1 estate we have seen no change to our network performance following their activity - ensuring consumers' smart meters remain unaffected.

Our second-generation meter solution has dual services: 2G/3G for central and south, and a proprietary long-range radio (LRR) network in the north. The LRR, which operates in the north region, is unaffected by 2G/3G sunsetting.

Our core SMETS2 service in the central and south will see 3G services turning off from the end of 2024, through 2025, and fall back to 2G only. Our service provider is obliged to support 2G until 2033, so we have a continuity of service for over 10 million 2G devices in our SMETS2 estate for the next 9 years.

It’s no surprise that the date of 2033 was chosen as the switch-off date for 2G – with existing agreements supporting this timetable. Contracts for second-generation meter technology were penned years ago with the ability to be extended to 2033, to give some degree of certainty and longevity.

The DCC network is a relatively low data network and initial analysis shows no customer impact and minimal overall service impact from the 3G switch-off. Our data requirements to support metering services are less than 2Mb per month per home. We are working closely with our service provider to ensure we understand and mitigate any service risk of their sunsetting activity.

When I look at the technology cycle for 2G, 3G, 4G through to 5G and even 6G, this represents a significant challenge. Connectivity of smart meters on our network is managed by a small device installed in every home, called a Communications Hub, which takes local messages from the meters and sends them securely across the national network run by the DCC. It is these Communications Hubs that are replaced, not the smart meters themselves. These hubs are relatively low cost and simple to replace, but at the scale of our network every small decision compounds.

The first generation of smart meters, or SMETS1, were built on a 2G (or 2.5g) service which was an early mobile data technology. Any remaining first-generation SMETS1 smart meters which have not been upgraded to SMETS2 as part of the ongoing programme of end of life replacement will need to be physically replaced before 2033, as these have been designed with an integrated 2G Communications Hub.

Our next-generation 4G Communications Hub will go into initial deployment later this year and into mass deployment from July 2025. This will be the platform for the next two decades. While we use the term 4G, the technology within our Communications Hub is aligned to the LTE standard which operates under 5G and will be included in 6G standards.

Our new partnership with Vodafone delivers 4G connectivity to Britain’s smart meter network with a 15-year agreement, enabling households to manage their energy use and supporting the move towards net zero for many years to come. 

Over the last two years we have spent time with the core component suppliers and watched the development of the cellular specifications, and emerging new standards that go unseen at a consumer level within the Global Standards 3GPPP. Global Standards are now on 3G-PPP-R18 set for final release in June of 2024. Release 19 is planned for the end of 2025 and 6G is likely to be developed in Release 20 which will likely be finalised in 2027 with 6G networks appearing from 2030.

LTE is integral across all releases and, as standards develop, chipset manufacturers will develop their solutions. There are LTE options within the standard, LTE-Cat1, Cat M, CAT-1Bis, RedCap, all supporting different use cases that we will evolve and support based on the future use cases of smart metering.

In 2025/26 the DCC will review the current product to ensure we have the right balance of cost and capability to future proof our Communications Hubs throughout the next decade. We will continue to review this every five years to ensure we maximise the longevity of each device.

New technology introduced too early brings a cost premium and industry pays for early replacement. Leaving technology in place for too long represents a technology debt, and possibly impacts system performance.

Take mobile phones, for comparison: most of us own and pay for these at a price significantly higher than the cost of our Communications Hubs. If I were to look at the devices available in 2007 that were commonplace – typical suppliers in 2007 were the likes of Nokia, and the N95 was its latest release. Blackberry and HTC were all the common names, while Apple was yet to release its first mobile device. When Apple launched its first phone in June 2007, it was a 2G-only device; in the 15 years since, it has already spanned across 2G, 3G, 4G, launched a 5G device and is most likely already considering technologies well beyond 5G.

At the DCC, our hardware is planned to offer an easier upgrade to the next evolution without a complete re-design.

The core reason is that in order to meet our service obligations we must support coverage reaching more than 99% of the UK population. No mobile operator today can offer this level of coverage for 5G, and it’s likely to take multiple years for service providers to offer coverage at these levels for 5G.

To ensure we can meet the coverage obligations, we have selected a solution that balances coverage with service capability. Our research indicates that this standard will most likely span multiple decades into the future. 

In the technology office of the DCC we’re actively considering our approach to sunsetting across all elements of the infrastructure we operate. It’s not just a cellular 2G, 3G to 4G challenge - it touches every element of our infrastructure. To ensure we understand all these challenges, members of the CTO team are joining the relevant standards bodies, including the 3G-PPP standards group, the Zigbee or SMIP HAN working group, and the OPEN-RAN working group.

This engagement provides us with a voice for standards development and insight into future challenges.

It would be able to support 2G, 3G, 4G and beyond, to ensure our smart metering devices remain connected as long as possible; but I understand there are technical limitations within which we need to work.

Sunsetting is not just a connectivity issue – all infrastructure operators deal with hardware and software sunsetting challenges. At the DCC we will always prioritise security, resilience, and value for money as the key drivers for our technology refresh roadmap.

The DCC will remain focused on delivering value for money and balancing the introduction of new technology at the right time to deliver the services our customers need.  

We'll have a louder voice on the standards bodies, ensuring we remain relevant, connected, secure and the right platform and - in the Government’s words - 'the backbone of a new digital energy infrastructure'.