With the advent and popularity of the smartphone, mobile data usage has been steadily increasing year over year along a steep trend line that is expected to continue. Technology continues to advance to improve spectrum efficiency, but more spectrum will be needed to meet the mobile data demand. Licensed spectrum has been used by operators as the raw material to deliver wireless data for mobile and nomadic use cases. Incumbents who do not utilize their spectrum very often, in both the temporal or geographical domain, create an opportunity for a shared spectrum allocation in which mobile services can utilize the spectrum when the incumbent is not operating. However, licensed spectrum has fueled the smartphone revolution. So, it is important to continue to provide enough spectrum runway so that mobile data network supply can continue to meet mobile network demand. Allocation of licensed, shared, and unlicensed spectrum is necessary for the success of 5G. However, the focus of this paper is on licensed spectrum. Allocation of spectrum under one regulatory approach is not a substitute for the other. Future spectrum should be allocated and deployed in areas where it can provide the most benefit to wireless consumers.