Our heterogeneous network raises several key concerns on
how to manage effective charging among these sensors that
harvest in multiple bands. Specifically, we address the scenarios
of: (i) the primary source of wireless energy suddenly
becoming unavailable, say, the TV station stops transmission
owing to its established broadcast schedule (unknown to the
sensors), power outages, etc. and (ii) the loss of energy
signal due to device mobility, i.e., the device moves out of
the transmission range of the ET. These issues pose several
challenges on (i) how to sustain the communication among
heterogeneous sensors when such situations occur, (ii) how to
optimally deliver wireless energy to the heterogeneous sensor
networks, and (iii) the challenges in aggregating the charging
action of multiple sensors.