The next generation of wireless networks aim to enable a data-driven society in which the connected devices must be able to operate with little or no human intervention for prolonged periods of time. To provide uninterrupted, perpetual operation for these devices, harvesting radio-frequency energy is a viable alternative, which gives rise to wirelessly powered communication networks. In this thesis, we investigate the building blocks of wirelessly powered communication networks and we propose communication protocols that achieve the fundamental limits of information flow, as well as protocols that decrease the congestion of the shared wireless channel for general machine-type communication networks.