The UK regulator plans to auction spectrum in the 2.3GHz and 3.4GHz bands between late 2015 and early 2016.
It will auction a total of 190MHz of spectrum in the two bands, which is said to be equivalent to around three-quarters of the airwaves released by Ofcom through the 4G auction in 2013.
It has invited potential bidders to comment on its proposals, which include a reserve price of between £2.5 million to £5 million per lot for the 2.3GHz spectrum, and £1 million for the 3.4GHz spectrum. The total value of the proposed reserve prices would be between £50 million and £70 million.
The spectrum is presently being used by the Ministry of Defence, and is being made available as part of a wider government initiative to free up public sector spectrum for civil uses.
"Today marks an important step in ensuring that the UK has sufficient spectrum to support our wireless economy,” said Philip Marnick, Ofcom Spectrum group director.
"It comes in response to the fast pace of change and innovation taking place in the communications sector, which is placing increased demands on how spectrum is used by all industries. One important way of meeting this demand is making new spectrum available and its use as flexible as possible."
Six countries presently use 3.4GHz spectrum, including the UK where UK Broadband operates its 'Relish' mobile broadband service in London.
Ofcom's consultation closes on 23 January 2015.