US Patent 7995644 Device, method and protocol for private UWB ranging

An apparatus, system, method and computer program product for secure ranging between at least two devices in radio communications with each other. In particular, an apparatus, system, method and computer program product for secure ranging between at least two devices communicating via ultra wideband (UWB) protocols. Either ternary-IR or time-hope-IR sequences are used for ranging and security. A first device transmits a range packet. A second device responds to the range packet after a delay time known only to the first and second devices. The delay time can be selected randomly by either to the first device or the second device and made known to the other device in an encrypted notification packet.