1. Collaborative Mobile Charging
Abstract:
The limited battery capacity of sensor nodes has become one of the most
critical impediments that stunt the deployment
of wireless sensor networks (WSNs). Recent breakthroughs
in wireless energy transfer and rechargeable lithium batteries provide a
promising alternative to power WSNs: mobile vehicles/robots carrying
high volume batteries serve as mobile chargers to periodically deliver
energy to sensor nodes. In this paper, we consider how to schedule
multiple mobile chargers to optimize energy usage effectiveness, such that
every sensor will not run out of energy. We introduce a novel charging
paradigm, collaborative mobile charging, where mobile chargers are
allowed to intentionally transfer energy between themselves. To provide
some intuitive insights into the problem structure, we first consider a
scenario that satisfies three conditions, and propose a scheduling
algorithm, PushWait, which is proven to be optimal and can cover a one-
dimensional WSN of infinite length. Then, we remove the conditions one
by one, investigating chargers' scheduling in a series of scenarios ranging
from the most restricted one to a general 2D WSN. Through theoretical
analysis and simulations, we demonstrate the advantages of the proposed
algorithms in energy usage effectiveness and charging coverage.