In this Thesis, Bluetooth is promoted as a technogy to enable location
aware services. The authors discuss the problems of trying to use RSSI
radio signal strength to triangulate position. They built a test system with
30 DLINK DBT-120 USB Bluetooth adapters costing $30 each and
using USB hubs with an external power supply. The USB hubs allow the
Bluetooth adapters to be initialized on a laptop and then disconnected from
the computer once initialized. As long as the power supply is not interrupted,
the beacons will continue to broadcast.