Abstract—In recent years, as wireless sensor networks (WSNs)
are widely diffused, multiple overlapping WSNs constructed on
the same area become more common. In such a situation, their
lifetime is expected to be extended by cooperative packet forwarding.
Although some researchers have studied about cooperation in
multiple WSNs, most of them do not consider the heterogeneity
in the characteristics of each WSN such as battery capacity,
operation start time, the number of nodes, nodes locations, energy
consumption, packet size and/or data transmission timing, and so
on. In a heterogeneous environment, naive lifetime improvement
with cooperation may not be fair. In this paper, we propose a fair
cooperative routing method for heterogeneous overlapped WSNs.
It introduces an energy pool to maintain the total amount of
energy consumption by cooperative forwarding. The energy pool
plays a role of broker for fair cooperation. Finally, simulation
results show the excellent performance of the proposed method.