  Indoor beacon system is a cornerstone of internet of things. Until now, most
of the research effort has focused on achieving various applications based on
beacon communication. However, the power consumption on beacon devices becomes
the bottleneck for the large-scale deployments of indoor networks. On one hand,
the size of beacon devices is required to be small enough for easy deployment,
which further limits the size of battery. On the other hand, replacing the
batteries of the beacon devices could lead to high maintenance costs. It is
important to provide them with full energy autonomy. To tackle this problem we
propose BEH: an indoor beacon system aimed at operating perpetually without
batteries. Our contributions are twofold. Firstly, we propose four methods to
increase the utilization efficiency of harvested RF energy in the beacon
system, by which the energy consumption level becomes low enough to fit within
the energy harvesting budget. Secondly, we implement BEH using Bluetooth Low
Energy (BLE) and Radio Frequency (RF) energy harvesting devices, and test BEH
extensively in a laboratory environment. Our test results show that BEH can
enable perpetual lifetime operation of mobile and static BLE beacon devices in
a (16 m$^{\text{2}}$) room. The average value of packet reception rate achieves
more than 99% in the best case.
