Protocol-Independent Detection of Passive Transponders for Near-Field Communication Systems

Near-field communication (NFC) devices, which is derived from radio frequency identification systems, provide a robust and simple wireless data interface. To make their use even more convenient, they shall always stay activated and scan the environment for passive communication partners. Usually, this is accomplished by protocol command inquiries. Since this interface is built into handheld battery-powered devices, power consumption is a major concern. Therefore, a low-power scan method is needed to ensure long battery life. We propose a solution that can easily be realized on silicon, can achieve a polling rate that ensures nearly no noticeable delay when establishing a connection, and consumes only 1% of the energy per interrogation when compared to the traditional approach. These tremendous savings in power make NFC viable for ad hoc networking.