  While backscatter communication emerges as a promising solution to reduce
power consumption at IoT devices, the transmission range of backscatter
communication is short. To this end, this work integrates unmanned ground
vehicles (UGVs) into the backscatter system. With such a scheme, the UGV could
facilitate the communication by approaching various IoT devices. However,
moving also costs energy consumption and a fundamental question is: what is the
right balance between spending energy on moving versus on communication? To
answer this question, this paper proposes a joint graph mobility and
backscatter communication model. With the proposed model, the total energy
minimization at UGV is formulated as a mixed integer nonlinear programming
(MINLP) problem. Furthermore, an efficient algorithm that achieves a local
optimal solution is derived, and it leads to automatic trade-off between
spending energy on moving versus on communication. Numerical results are
provided to validate the performance of the proposed algorithm.
