Recovering postdisaster communications has become a major challenge for
search and rescue. Device-to-device (D2D) and device-to-vehicle (D2V) networks
have drawn attention. However, due to the limited D2D coverage and onboard
energy, establishing a hybrid D2D and D2V network is promising. In this
article, we jointly establish, optimize, and fuse D2D and D2V networks to
support energy-efficient emergency communications. First, we establish a D2D
network by optimally dividing ground devices (GDs) into multiple clusters and
identifying temporary data caching centers (TDCCs) from GDs in clusters.
Accordingly, emergency data returned from GDs is cached in TDCCs. Second, given
the distribution of TDCCs, unmanned aerial vehicles (UAVs) are dispatched to
fetch data from TDCCs. Therefore, we establish a UAV-assisted D2V network
through path planning and network configuration optimization. Specifically,
optimal path planning is implemented using cascaded waypoint and motion
planning and optimal network configurations are determined by multiobjective
optimization. Consequently, the best tradeoff between emergency response time
and energy consumption is achieved, subject to a given set of constraints on
signal-to-interference-plus-noise ratios, the number of UAVs, transmit power,
and energy. Simulation results show that our proposed approach outperforms
benchmark schemes in terms of energy efficiency, contributing to large-scale
postdisaster emergency response.Comment: 12 page