Introduction

In order to satisfy the power thirst of communication devices in the imminent 5G era, wireless charging techniques have attracted much attention from both the academic and industrial communities. Although the inductive coupling and magnetic resonance based charging techniques are indeed capable of supplying energy in a wireless manner, they tend to restrict the freedom of movement. By contrast, radio frequency (RF) signals are capable of supplying energy over distances, which are gradually inclining closer to our ultimate goal—charging anytime and anywhere. Furthermore, transmitters capable of emitting RF signals have been widely deployed, such as TV towers, cellular base stations, and Wi-Fi access points. This communication infrastructure may indeed be employed also for wireless energy transfer (WET). Therefore, no extra investment in dedicated WET infrastructure is required. However, allowing RF signal based WET may impair the wireless information transfer (WIT) operating in the same spectrum. Hence, it is crucial to coordinate and balance WET and WIT for integrated data and energy transfer (IDET), which evolves to Data and Energy Integrated communication Networks (DEINs). To this end, the inherent relationship between WET and WIT is revealed in this chapter. Furthermore, a ubiquitous DEIN architecture is introduced by summarizing its natural heterogeneity and by synthesizing a diverse range of integrated WET and WDT.