There are disputes about almost every aspect of 5G, but one area of agreement – the cost of spectrum will have to go down to make most 5G business cases viable. Shared and unlicensed spectrum will play a far greater role than before, because while these are a double-edged sword for established MNOs, their need to keep costs under control will outweigh the threat of lowering barriers to entry for new rivals. Long before most will think about 5G, regulators and operators are already accelerating their work on new spectrum strategies to improve the economics of 4G and mobile data. At the recent Mobile World Congress, attention was certainly shifting from the whizzbang technologies and futuristic 5G use cases of…