UK telcos prepare to turn off 3G to boost energy efficiency

As 5G rollouts carry on and the conversation starts turning to 6G, older generations of mobile technology are becoming obsolete. If network equipment were an employee, 3G would now be at the stage of its career where it starts shopping for Spanish real estate as it looks forward to retirement. Some operators in Europe, North America and Asia have already switched off their 2G or 3G networks, freeing up spectrum for 4G and 5G, and more will follow in the coming years.

In the UK, all mobile network operators (MNOs) have pledged to turn off 2G and 3G by 2033. Much like most of Europe, the country's 3G network will likely be switched off before 2G, which is vital for machine-to-machine communications.

No British operator has entirely switched off its 3G network yet, but three have already announced deadlines, with O2 the only telco yet to confirm one. In an answer to Light Reading's email asking about the firm's 3G sunsetting schedule, a Virgin Media O2 spokesperson replied: "We're supportive of the Government's plans to switch off 2G and 3G networks by 2033. We’ll work closely with industry partners to develop our approach and we’ll provide further details on our plans in due course."

Vodafone, meanwhile, plans to complete the process by early 2024. The operator told Light Reading by email that it has already turned off 3G in Plymouth and Basingstoke and should soon do so in Hull and Oxford, with sunsetting to start in Glasgow in late July. Three, which has recently announced plans to merge with Vodafone, has also started the switching off process and plans to complete it by the end of 2024.

BT-owned EE, which has the most subscribers of all operators in the country, is also in the process of retiring 3G equipment. A company spokesperson told Light Reading via email that "EE’s 3G mobile network will be retired from January 2024, at which point it will be more than 20 years old." The company has conducted a localized pilot in Warrington, having switched off its 3G network in the town last week. The results of the pilot will inform 3G retiring across the network.

EE pointed out that "3G data use has fallen to record low levels across the UK and now accounts for less than 0.6 percent of all downloaded data on the EE network. Despite its falling usage, 3G accounts for up to 35 percent of the total power used in our mobile network." Refarming 3G spectrum will allow the operator to "run mobile networks more than ten times more efficiently on 4G." This will save energy equivalent to fully charging 4 billion to 6 billion smartphones, said the telco.

Energy efficiency

Several countries are well ahead of the UK when it comes to switching off 3G. Operators in Germany, Norway, the Czech Republic and Italy, among others, have already done so, and more are planning to follow suit. In the US, 3G sunsetting was completed in 2022.

Improved energy efficiency is among the main benefits of retiring 3G, and eventually 2G. As Grace Langham, research analyst at Analysys Mason, wrote last year, "MNOs that run 2G, 3G, 4G and 5G with separate base stations could potentially reduce their energy consumption by up to 40% at each macro site by switching off 2G and 3G."

Figure 2: (Source: Analysys Mason)

Vodafone, meanwhile, argues that "5G Massive MIMO is around 15x more energy efficient than 3G and 3x more efficient than 4G to deliver the same quantity of data."

In Germany, Telefónica O2's 3G sunsetting, completed in 2021, saves 60GWh annually – according to information the company supplied in a Carbon Disclosure Project (CDP) questionnaire.

Research from Light Reading's sister company Omdia indicates spectrum constraints are among the main drivers for retiring older mobile generations as 4G and 5G achieve greater spectrum efficiency and network capacity. This is important for MNOs as demand from data-intensive applications grows.

Mikael Schachne, VP for Telco Market at BICS, told Light Reading that telcos need the frequencies currently used for legacy technologies to roll out 5G. He pointed out that many operators are facing congestion on their 4G networks and need 5G to supply data services. "You need to go to 5G and for that you need frequencies and the only way to get those frequencies is, sometimes, to refarm 2G and 3G," he said.

Refarming spectrum also helps telcos reduce CO2 emissions, with the GSMA estimating that for a high-income country of 80 million, the cumulative impact of not refarming 3G spectrum is an extra 3 million tonnes of CO2 equivalent (MtCO2e) emitted over a ten-year period. This falls to 2 MtCO2e in a low-income country of a similar size.

And while the ongoing heatwaves in Spain and elsewhere are a reminder of why that's important, ultimately network executives may be even more focused on the slimming effect energy efficiency has on opex. The GSMA has pointed out that "network opex tends to account for around 25% of the operator cost base, or 10% of revenue." It also notes that energy costs represent more than 90% of network costs.

According to data from Omdia, Telefónica – Telefónica O2's parent company – paid $138 per GWh on average in 2021, which was also the median cost across major operators. Based on that price, Light Reading has calculated that saving 60GWh would mean cutting costs by $8.28 million a year.

3G to retire ahead of 2G

Across Europe, 2G will have to soldier on for longer than its younger sibling, with most operators planning to switch off 3G first. The problem lies mainly with machine-to-machine communications and IoT, which still rely heavily on the 2G network.

UK smart meters, for example, which connect to 2G and 3G, may already be negatively impacted by a 3G switch-off, according to some in the industry. In many countries, 2G is also still used because of its low-power operation and good low-frequency coverage, particularly in rural areas.

France is the outlier, with both SFR and Bouygues planning to shut down 2G by 2026, with 3G to follow in 2028 and 2029, respectively. Orange is planning to turn off 2G by 2025, and 3G by 2028. During the 2022 Mobile World Congress, where the announcement was made, Orange CTO Michaël Trabbia said this was because the French government put pressure on operators to roll out 3G and 4G faster than 2G, and that the operator has better 3G coverage in France as a result. Orange, however, plans to retire 3G before 2G in its other European markets.

Back in 2022, Trabbia also noted that roaming will be another obstacle to the 2G switch-off as most roaming agreements were still focusing on 2G.

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— Tereza Krásová, Associate Editor, Light Reading