  Similar to the evolution from the wired Internet to mobile Internet (MI), the
growing demand for power delivery anywhere and anytime appeals for power grid
transformation from wired to mobile domain. We propose here the next generation
of power delivery network -- mobile power network (MPN) for wireless power
transfer within a mobile range from several meters to tens of meters. At first,
we present the MPN's concept evolution and application scenarios. Then, we
introduce the MPN's supporting technology, namely resonant beam charging (RBC).
As a long-range wireless power transfer (WPT) method, RBC can safely deliver
multi-Watt power to multiple devices concurrently. Meanwhile, the recent
progress in RBC research has been summarized. Next, we specify the MPN's
architecture to provide the wide-area WPT coverage. Finally, we discuss the
MPN's features and challenges. MPN can enable the ultimate mobility by cutting
the final cord of mobile devices, realizing the "last-mile" mobile power
delivery.
