This report traces the current and possible future evolution of mobile communications networks and some of the changes in spectrum policy that might better accommodate innovation. Congress at present is engaged in debates over how to maximize the value-economic, monetary, or other-of upcoming auctions for spectrum licenses, notably the Broadcast Incentive Auction required by the Spectrum Act in 2012 (P.L. 112-96, Title VI). The evolution of wireless technologies, as outlined in this report, indicates that auctions, as presently structured, are a limited policy tool. Congress, therefore, may move to reconsider the current goals of spectrum policy to more fully accommodate the development of the next generation of wireless technologies. In future reviews of communications law and spectrum policy, Congress may choose to broaden its scope to include spectrum-dependent industries and technologies beyond the telecommunications sector.