THE curious, vital and largely unnoticed world of radio communications - the clever stuff which gives us wi-fi and mobile phone reception - goes on around us every day.

How it changed so rapidly and became so important to the modern world was explained in A talk by Professor Nigel Linge from the School of Computing at the University of Salford.

Prof Linge was speaking at the autumn conference of the Cumbria Industrial History Society held at Caldbeck village hall.

He said: "At no point in previous times have we been so reliant on radio."

Modern uses of radio waves include everything from satellite navigation and television signals to mobile phones and wi-fi links.

He said: "Telecommunications in many ways is the invisible industry - unless you know where to look for certain parts of it such as towers and masts."

What struck him most was the accelerating rate of change in telecommunications - which has left little physical record as one system replaced another.

The first radio transmission from the United Kingdom to France as in 1899 and by December 1901 radio signals could cross the Atlantic by cable - a method making a comeback in the era of optical fibre.

In 1922 we had a radio station at London and in Manchester at the Metropolitan Vickers factory in Trafford Park.

They relied on very tall masts to get the radio signal out.

He said: "You really need the aerials as high as you possibly can."

By 1926 the Imperial Wirnceeless Chain allowed the global transmission of telegraph messages by Morse code - almost putting earlier sea bed cables out of business.

In November 1936, BBC television signals were being broadcast from a 215ft tower.

By comparison, the 1966 mast at Winter Hill, near Bolton, stands at 1,015ft.

The tallest mast is at Skelton, near Penrith, Cumbria, at 1,198ft.

In the past 30 years, microwave dishes on masts, towers and roof tops have provided greater access to mobile phone services.

He said: "Mobile has really brought radio into dominance."

The bulk of the masts are on, or near, major roads and in the centre of towns and cities - and the higher the frequency of the signal, the smaller the antenna.

The first United Kingdom mobile network was launched on January 1 in 1985.

By 2020 mobile phones will have gone through five generations of development - with little to show on the ground.

He said: "Towers and masts are sadly not seen as being iconic.

"The mobile phone industry is rubbish at recording its own history."

Only BT - which was a former government department - had a good archive, he said.

With Andy Sutton, Prof Linge is the author of 30 Years of Mobile Phones in the UK by Amberley Publishing.