Download speeds of 10Mb are needed in order to ensure UK consumers receive an effective quality of service, Ofcom has claimed.
In its new Citizens and Communications Services report, the media regulator revealed average speeds have increased to 18.7Mb and super-fast broadband is now available to 78 per cent of the country.
However, it claimed that the connectivity picture remains uneven in Britain, with some areas remaining underserved by fibre networks.
"A significant minority of households, particularly those in rural areas, receive poor speeds but are currently unable to upgrade to faster services," Ofcom stated.
The regulator suggested that, with many broadband connections now supporting multiple users, there is an "increasingly compelling argument" that speeds of less than 10Mb are inadequate.
Ofcom explained that - despite continuing upgrades - some homes are still unable to access a service of at least 2Mb.
"Superfast broadband coverage has increased rapidly, but remains short of universal coverage," it stated.
The regulator added that there are "challenges" around rural coverage and also some urban 'not-spots' - parts of towns and cities that are yet to benefit from network upgrades.
Ofcom said it is taking action to improve UK connectivity by providing technical advice to support the government's rollout programme, and by publishing broadband speeds data by provider to help consumers make informed choices.
Patricia Hodgson, Ofcom Chairman, noted that consumers' ability to access, use and rely on communications services determines how fully they can play a part in UK economy, society and culture.
She claimed Britain has "a strong record" of meeting the communications needs of its citizens, but there is more work to do, particularly where service quality and broadband coverage are concerned.
Ofcom Chief Executive Ed Richards said that, like all developed economies, the UK is "completely transforming" its communications infrastructure.
He noted that when Ofcom began - in 2003 - fixed broadband and mobile data use were in their infancy.
"Today, we are on the way towards a transformation of our digital networks, with super-fast broadband and 4G mobile data services spreading across the country and take-up rising fast," Mr Richards added.
"We need more investment, better coverage, faster services and higher rates of take-up, with the kind of competition that has positioned the UK well so far."
He claimed that, if the UK can maintain the current rate of progress and continue to improve availability, there are going to be "more exciting and more widespread opportunities for growth and innovation across the UK".