Ofcom is planning a fresh spectrum auction that will improve 4G coverage later this year. The regulator has 190 MHz to allocate to the major mobile networks, and today it's launched a consultation with possible auction formats. The concern is that some of the biggest carriers are undergoing mergers -- BT is buying EE, while the owner of Three UK is trying to acquire O2. if Ofcom awards all of the spectrum now, the balance of power could change unexpectedly if the deals don't proceed as planned. However, it could be six months before they're approved, and even longer before the transactions are completed, and the regulator doesn't want to waste any time putting the spectrum to good use.