Assembly Research founder Matthew Howett told BBC News the change would probably come sooner than the government's 2033 deadline.

The switch-off will affect all sorts of older devices, such as 3G-only smartphones.

And it would be crucial for the government to act on behalf of consumers who may be slow to adjusting, Mr Howett said.

"There is an important consumer-protection dimension to all this," he said.

"You will of course have some people who may still rely on a 2G/3G-enabled handset to make calls in emergencies but also because devices such as smart meters run off the 2G network.

"Involving these stakeholders will be crucial to avoid disruption."

Matthew Howett, an industry analyst and founder of research firm Assembly, told the BBC some degree of consolidation in the industry now seemed certain.

"If that results in giving stability and scale to those alt-nets in their competitive battle with the larger incumbents then ultimately that can't be a bad thing for consumers," he said.

"A competitive fibre rollout is arguably Ofcom's flagship policy and so any early indications the Equinox offer is having a negative impact for consumers you would think would be met with intervention. It's a bit like a pair of scales that are precariously balanced - we'll need time to see where they settle."

In some remote locations, coverage will be "on demand" delivered by satellites.

"Affordability could remain a challenge with higher monthly rentals and considerable upfront costs. Subsidies could help bring those costs down," analyst Matthew Howett, founder of Assembly Research, told the BBC.

But Mr Howett said the expansion would help EE to position itself ahead of rivals - such as Virgin Media and O2 - among customers who value connectivity, whether rural or not.

"The importance of the network is only going to grow, particularly as more of the things we own and use become connected, and it's not just about the phone in our pockets.

"Whoever has the most advanced, widespread, secure and reliable network, is going to emerge the winner," he said.

Matt Howett, from analysts Assembly Research, added: "Recognising the need to be connected, and the financial hardship customers faced, many operators have taken steps to ensure access to vital services.

"We've really seen the sector step up and respond to the challenging circumstances many customers have found themselves in."

But Assembly consultancy founder Matthew Howett said: "As end-of-term reports go, it's a pretty encouraging one .

"More households are taking higher-speed packages than last year.

"But take-up of gigabit-capable broadband is still fairly low."

Another observer - Matthew Howett, founder of research firm Assembly - added: "The original target for 2025 was always an ambitious one, but crucially one that industry felt it could deliver with the right enabling regulatory environment.

"While progress was made with that, a number of barriers still remain. To depart from the original target with four years still left to run suggests perhaps that mountains can't be moved after all."

"We know these are the hardest to reach and most expensive households to connect, where there are real barriers and real costs to deploying broadband, and where further government subsidy may be needed," said Matthew Howett, founder of research firm Assembly.

"Sometimes eye-watering quotes might arise because of estimates made without full engineering surveys having yet been completed. We're still at the early stages of the scheme so Ofcom's investigation may result in useful guidance when calculating quotes for future requests."

Telecoms analyst Mathew Howett, from Assembly Research, said: "There is very clearly a cost to the industry in terms of replacing Huawei earlier than operators might have done naturally.

"Government can't expect the industry to speed up deployment of networks if they pile on additional cost and slow down that rollout."

But he added: "The last time the government directed Ofcom with regards to spectrum - the liberalisation of bands for 4G and associated annual licence fees - legal challenges went on for a decade."

"It's not only a very expensive process for the operators, but it's going to be a time-consuming one as well because they need to get access to all those sites to make the changes," added Matthew Howett from Assembly, the consultancy that wrote Mobile UK's report.

One thing practically everyone agrees on is that the matter needs to be settled once and for at a time when so much else about the economy is uncertain.

"These procurement decisions can take 18 months to two years to finalise and it takes time to ramp up supply to meet the demand," said Mr Howett.

"So this isn't just a question of overnight deciding not to use Huawei - it would take many years to do it properly."

Matthew Howett, founder of research firm Assembly, sympathised with Openreach's frustration over business rates.

"It's a barrier that the whole industry is behind removing. Currently in England the exemption only lasts for five years, and 10 years in Scotland, but for the operators the business case for rolling out fibre is over a much longer period, often over 15 years."

He also acknowledged that "broadband, while digital, can still be a very analogue and labour-intensive job to install".

"As much as 70% of the cost of rolling out broadband is in the civil works - the digging, manual labour and road closures that go with it. So, any innovations that reduce these costs will ultimately result in broadband being deployed faster, and to more people."

But full-fibre broadband, where ultra-fast optical cables carry data right into your home or office, is currently the "gold standard".

"There is no doubt that we need fibre connectivity, in particular all the way to the home. That's something everybody is on board with across the industry and political parties," said Matthew Howett, an analyst at Assembly Research.

However, the government plans to auction lower-frequency spectrum - freed up from the digital TV switchover - for 5G services.

"The 700MHz frequency band that will be auctioned is good at covering large rural areas," said Mr Howett. "Anything freed up from that switchover from analogue to digital TV means you can reach more people with fewer base stations."

Matthew Howett, founder of research firm Assembly, said the announcement made "commercial sense" because Openreach and others looking to upgrade the UK's infrastructure needed to prove that the demand is out there.

"This does seem like a genuine move to get more people onto the fibre network, and stave off criticism from those that say the UK falls behind," he said.

"It's about Openreach showing the industry and the regulator that it has changed and is implementing the further separation from BT not only to the letter, but also in the spirit of what was agreed."