  Wireless charging is a technology of transmitting power through an air gap to
electrical devices for the purpose of energy replenishment. The recent progress
in wireless charging techniques and development of commercial products have
provided a promising alternative way to address the energy bottleneck of
conventionally portable battery-powered devices. However, the incorporation of
wireless charging into the existing wireless communication systems also brings
along a series of challenging issues with regard to implementation, scheduling,
and power management. In this article, we present a comprehensive overview of
wireless charging techniques, the developments in technical standards, and
their recent advances in network applications. In particular, with regard to
network applications, we review the mobile charger dispatch strategies, static
charger scheduling strategies and wireless charger deployment strategies.
Additionally, we discuss open issues and challenges in implementing wireless
charging technologies. Finally, we envision some practical future network
applications of wireless charging.
