  The recent advances in wireless energy transfer (WET) provide an alternate
and reliable option for replenishing the battery of pervasive and portable
devices, such as smartphones. The peer-to-peer (P2P) mode of WET brings
improved flexibility to the charging process among the devices as they can
maintain their mobility while replenishing their battery. Few existing works in
P2P-WET unrealistically assume the nodes to be exchanging energy at every
opportunity with any other node. Also, energy exchange between the nodes is not
bounded by the energy transfer limit in that inter-node meeting duration. In
this regard, the parametric heterogeneity (in terms of device's battery
capacity and WET hardware) among the nodes also affects the energy transfer
bound in each P2P interaction, and thus, may lead to unbalanced network energy
distributions. This inherent heterogeneity aspect has not been adequately
covered in the P2P-WET literature so far, especially from the point of view of
maintaining a balanced energy distribution in the networked population. In this
work, we present a Heterogeneity-aware Wireless Energy Transfer (HetWET)
method. In contrast to the existing literature, we devise a fine-grained model
of wireless energy transfer while considering the parametric heterogeneity of
the participating devices. Thereafter, we enable the nodes to explore and
dynamically decide the peers for energy exchange. The performance of HetWET is
evaluated using extensive simulations with varying heterogeneity settings. The
evaluation results demonstrate that HetWET can maintain lower energy losses and
achieve more balanced energy variation distance compared to three different
state-of-the-art methods.
