
532 Cyber-Physical Systems: From Theory to Practice
21.2 THE MODEL
Our model features three types of devices: stationary nodes, mobile chargers, and one stationary
control center. The control center acts as a sink for the data that are routed throughout the network.
We assume that there are N nodes of wireless communication range r distributed at random in a
circular area of radius R. We virtually divide the network into slices, the number of which is equal
to the number of the mobile chargers. K mobile chargers initially deployed at coordinates (x, y) =
R
2
cos(
π
K
(2j −1)),
R
2
sin(
π
K
(2j −1))
of the circular area, where j =1,2,..., K − 1 (one mobile
charger ...