Location management for radio frequency identification readers

Abstract

A Radio Frequency Identification (RFID) system for managing and identifying locations for an RFID reader is disclosed. An expected location of a fixed radio frequency identification (RFID) reader is determined. A first signal is transmitted from the reader to a first RFID tag to determine whether the reader is at the expected location. The first tag is a fiducial RFID tag fixed at a first location. In one aspect, the reader receives a first response to the first signal from the first tag. The first response identifies the first location of the first tag. The first location is compared to the expected location. If the first location and the expected location are different, an alarm is triggered.

Description

TECHNICAL FIELD[0001]This disclosure relates generally it Radio Frequency Identification (RFID) systems, and in particular but not exclusively, relates to location management for RFID readers.BACKGROUND INFORMATION[0002]Goods and other items may be tracked, and identified using a radio frequency identification (RFID) system. The RFID system includes an RFID tag, which is typically placed on the item to be tracked. The RFID tag is a small transponder that can be read by an RFID reader (also referred to as an RFID interrogator). The reader includes a transceiver and an antenna. The antenna emits electromagnetic (EM) waves generated by the transceiver, which, when received by the tag, activate the tag. Once the tag has been activated, the tag communicates using radio waves back to the reader, thereby identifying the item to which the tag is attached or is otherwise associated with. In one form of RFID, the tag modifies and reflects the waves emitted by the reader, using the modified an...

AI Technical Summary

Benefits of technology

[0006]The present invention relates to a Radio Frequency Identification (RFID) system for managing and identifying locations for an RFID reader. Fixed RFID tags, referred to as fiducial tags, may be used to identify a current location of an RFID reader. The fiducial tags may be embedded in structural elements of a building, such as in a doorway where inventory is tracked as it leaves or enters the building. In one exemplary aspect, an RFID reader placed in proximity to the doorway reads RFID tags placed on tracked items passing through the doorway. To ensure a reader owner / administrator that the reader is indeed covering the intended doorway, the reader reads one or more fiducial tags positioned at the doorway. The response from the fiducial tag includes information which may be decoded into a specific location associated with the fiducial tag. Since the fiducial tags are substantially immobile and represent a fixed location, if a reader reads a fiducial tag associated with the reader's intended location, the reader's location is verified, thereby assuring a reader owner that the reader is covering its intended area, among other benefits.

[0008]In another aspect, a mobile RFID reader may read a fiducial tag to affect the function of the reader. For example, upon reading a specific fiducial tag, the reader may associate subsequently scanned tagged inventory items with the fiducial tag location. In one aspect, upon reading a specific fiducial tag, the reader may alter its mode of operation, or its status (e.g. on / off). In one aspect, the reader may adjust its effective range by controlling some aspect of its ability to read tags (such as output power). In this way, the reader at full power could be used to find a fiducial tag at some large distance, and then the power of the reader is subsequently reduced. This will enable the reader to successively move closer and closer to a fiducial tag by narrowing the area covered by the reader.

[0009]In another aspect, combinations of fiducial tags and item tags can be used to provide a convenient means of mapping the location of mobile tagged items, or assisting in the location of these items through association with one or more fiducial tags.

Problems solved by technology

If the reader location is uncertain, some applications of RFID can be compromised.

In such an application, if the reader is unexpectedly moved, or if the reader malfunctions, there may be adverse results.

For example, the reader owner may falsely assume that a particular doorway is being covered by the reader, or the reader may report an incorrect location for an object.

In another situation, the reader may become shielded or damaged in some way, so that the coverage area of the reader becomes greatly diminished without notification to the network, and all or some tags pass by the reader without being detected, either intermittently or for an extended period of time.

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