The government has opened a consultation to understand what makes investing in full fibre and 5G "attractive".
The responses will inform the Department for Digital, Culture, Media & Sport's (DCMS) Telecoms Infrastructure Review, due to be published in summer.
Digital minister Matt Hancock said the government wants to have at least 10 million premises connected to full fibre, in the next decade "with a clear path to national coverage".
He said the review will determine "how to deliver the competitive conditions to encourage the long-term investment needed to secure ubiquitous world-class digital connectivity".
The transition from copper to full-fibre networks across the UK "is necessary to future-proof the speed, capacity and reliability of fixed connections, and create the backbone of 5G mobile networks".
Last year the government committed £400m to a "full-fibre" Digital Infrastructure Investment Fund, which would enable matched private sector finance to invest in new fibre networks over the next four years. However, the pot is yet to make a significant difference.
On 5G, Hancock said: "We want the UK to be a global leader in 5G so that we can take early advantage of the benefits that this new technology offers. The steps we are taking now are all part of our commitment to realising the potential of 5G, and will help to create a world-leading digital economy that works for everyone."
The first commercial UK and EU deployments of 5G aren't expected to get started until around 2020.
The government recently committed £25m to 5G test beds, having previously promised £160m from the National Productivity Investment Fund (NPIF) in the Autumn 2017 Budget.
DCMS will close the six-week call for evidence on January 30. It hopes to understand what market or policy interventions might support long-term investment in the next generation of telecoms infrastructure. ®