Internet of MIMO Things: UAV-Assisted Wireless-Powered Networks for Future Smart Cities

Widespread and pervasive IoT adoption is threatened by finite-capacity batteries of wireless devices. To mitigate this issue, energy harvesting (EH) and wireless power transfer (WPT), in addition to energy-efficient communication techniques, have been widely explored. Although these efforts have achieved longevity to some extent, ever-evolving IoT services seek fully autonomous things without energy constraints. To meet this demand and relieve the ongoing networking challenges, we propose a new concept called the Internet of MIMO Things (IoMIMO). IoMIMO envisions a self-sufficient architecture that adopts only single- and double-hop energy and data transitions to enable efficient energy sharing and reduced data traffic in networks. In particular, single hops are performed by hybrid access points (HAPs), while relaying via double hops is actuated by unmanned aerial vehicles (UAVs). The HAPs will handle multiple-input multiple-output (MIMO) of energy and data, and coordinate their transitions between the network components in a concurrent and automated manner. Benefiting from the recent advances in multi-source EH, WPT, and UAVs, IoMIMO can fulfill smart city services without being limited by energy constraints and/or networking challenges. Device types specialized for IoMIMO and their operation modes are evaluated in a simple network scenario to clearly explain the principles and the potential benefits of the envisioned concept. Future research directions are also identified to ease the realization of such a next-generation networking architecture.