A system for dispensing, receiving, and tracking towels or other items includes a cabinet structure having first and second interior spaces. An access door provides access to the first interior space, and a return door permits items to be returned to the second interior space. An RFID system conducts read operations to determine how many items having RFID tags are disposed in the first and second interior spaces. The system determines what items have been removed from the first interior space, and associates removed items with specific users. The RFID system conducts read operations as items are returned to the second interior space and credits the user.

Systems and methods for remote sensing are described. In an embodiment, an apparatus, includes: a radio frequency identification (RFID) tag; an electromagnetic transmitter configured to emit electromagnetic waves; an ultra-wideband (UWB) receiver; a computer system; where: the RFID tag is configured to be operated without a battery, and to be powered by the electromagnetic waves emitted by the electromagnetic transmitter; where the RFID tag is configured to send out UWB impulses based on an amount of electromagnetic power received from the electromagnetic transmitter, such that a repetition rate of the UWB impulses varies with the amount of electromagnetic power received from the electromagnetic transmitter

A Radio Frequency Identification (RFID) system including an RFID reader and a reader proxy authenticates itself to a verification authority. The proxy receives a proxy challenge from a verification authority and determines a proxy response based on the proxy challenge and a proxy key known to the proxy. The proxy response is then sent to the verification authority along with an identifier for the reader. The reader then authenticates an RFID tag by sending a tag response to the verification authority, which determines whether the reader is authentic based on the authenticity of the proxy response.

An Integrated Circuit (IC) for an RFID tag includes at least two antenna ports for coupling to at least two antennas. The IC may be configured to determine the port from which it receives an input signal, and provide a first functionality if it receives the input from a first port and a second functionality if it receives the input from a second port. The IC may be configured to determine and/or offer a functionality based on the receiving port.

An Integrated Circuit (IC) for an RFID tag includes at least two antenna ports for coupling to at least two antennas. The IC may be configured to determine the port from which it receives an input signal, and provide a first functionality if it receives the input from a first port and a second functionality if it receives the input from a second port. The IC may be configured to determine and/or offer a functionality based on the receiving port.

A Radio Frequency Identification (RFID) system including an RFID reader and a reader proxy authenticates itself to a verification authority. The proxy receives a proxy challenge from a verification authority and determines a proxy response based on the proxy challenge and a proxy key known to the proxy. The proxy response is then sent to the verification authority along with an identifier for the reader. The reader then authenticates an RFID tag by sending a tag response to the verification authority, which determines whether the reader is authentic based on the authenticity of the proxy response.

A Radio Frequency Identification (RFID) system including an RFID reader and a reader proxy authenticates itself to a verification authority. The proxy receives a proxy challenge from a verification authority and determines a proxy response based on the proxy challenge and a proxy key known to the proxy. The proxy response is then sent to the verification authority along with an identifier for the reader. The reader then authenticates an RFID tag by sending a tag response to the verification authority, which determines whether the reader is authentic based on the authenticity of the proxy response.