  Unmanned aerial vehicles (UAVs) are usually dispatched as mobile sinks to
assist data collection in large-scale wireless sensor networks (WSNs). However,
when considering the limitations of UAV's mobility and communication
capabilities in a large-scale WSN, some sensor nodes may run out of storage
space as they fail to offload their data to the UAV for an extended period of
time. To minimize the data loss caused by the above issue, a joint user
scheduling and trajectory planning data collection strategy is proposed in this
letter, which is formulated as a non-convex optimization problem. The problem
is further divided into two sub-problems and solved sequentially. Simulation
results show that the proposed strategy is more effective in minimizing data
loss rate than other strategies.
