Abstract: Methods, systems and apparatuses for RFID readers forming a reader network are described. In an aspect of the present invention, a plurality of RFID readers are configured to interrogate tags. Furthermore, the readers are configured to communicate with one another by transferring a token, represented by a signal. Possession of the token enables the reader to access a RF communications medium. Readers can be arranged in a ring configuration, and interconnected via wired links. A secondary token may circulate in the ring in addition to the primary token, to ensure redundancy in the system. A reader waits for a predetermined time interval before accessing the RF communications medium.

Abstract: RFID methods, systems and apparatus for writing common data (RFID information) to a plurality of RFID tags, include transmitting a common-write data signal including the common data to a plurality of RFID tags located in a broadcast field, where the plurality of RFID tags receive and respectively write the common data in internal memory of the plurality of RFID tags in accordance with a common algorithm. A common-write data signal may include common identifier data. Each of a plurality of RFID tags may generate common identifier data by controlling a random number generator of the tag. Each of a plurality of RFID tags may be pre-configured (initialized) for receiving common data and writing the common data to memory in accordance with a common algorithm. Each of a reader and a plurality of RFID tags may include common algorithm for transmitting/receiving and executing a common-write-enable command that enables a common write capability of a tag (e.g.

Abstract: Methods, systems, and apparatuses for verifying singulated tags are described. A radio frequency (RF) signal is transmitted to provide power to at least one tag. A powered tag is singulated. A delay time period is waited. A read verify command is transmitted to the singulated tag. A response is received to the read verify command. The response to the read verify command is verified to determine whether it was received from the singulated tag.

Abstract: Methods, systems, and apparatuses for reading tags of tag populations are described. Rather than interrogating a tag population in a single query round, interrogations of tag populations are performed using reduced transmit power levels over multiple query rounds, each query round reading a portion of the tag population. In this manner, an overall power amount expended to transmit interrogations signals is reduced, while maintaining a substantially similar read rate as in single query round interrogations.

Abstract: Methods, systems, and apparatuses for verifying singulated tags are described. A radio frequency (RF) signal is transmitted to provide power to at least one tag. A powered tag is singulated. A delay time period is waited. A read verify command is transmitted to the singulated tag. A response is received to the read verify command. The response to the read verify command is verified to determine whether it was received from the singulated tag.

Abstract: Methods, systems and apparatuses for RFID readers forming a reader network are described. In an aspect of the present invention, a plurality of RFID readers are configured to interrogate tags. Furthermore, the readers are configured to communicate with one another by transferring a token, represented by a signal. Possession of the token enables the reader to access a RF communications medium. Readers can be arranged in a ring configuration, and interconnected via wired links. A secondary token may circulate in the ring in addition to the primary token, to ensure redundancy in the system. A reader waits for a predetermined time interval before accessing the RF communications medium.

Abstract: A method for reading and tracking radio frequency identification (RFID) tags in the presence of a noisy air channel is provided. In accordance with the method, a binary tree data structure is used to characterize a plurality of RFID tags, each of which is associated with a unique identification (ID) number. During communication between a tag reader and one or more RFID tags, the tag reader traverses the binary tree, eliminating tags from communication until one tag with a unique ID number is isolated and verified. As the binary tree is traversed, counters associated with each node in the tree are incremented based on tag matches, such that, over time, counters associated with nodes in tag-populated branches will tend to have a high value and counters associated with nodes in unpopulated tree branches will tend to have low values.

Abstract: A method for reading and tracking radio frequency identification (RFID) tags in the presence of a noisy air channel is provided. In accordance with the method, a binary tree data structure is used to characterize a plurality of RFID tags, each of which is associated with a unique identification (ID) number. During communication between a tag reader and one or more RFID tags, the tag reader traverses the binary tree, eliminating tags from communication until one tag with a unique ID number is isolated and verified. As the binary tree is traversed, counters associated with each node in the tree are incremented based on tag matches, such that, over time, counters associated with nodes in tag-populated branches will tend to have a high value and counters associated with nodes in unpopulated tree branches will tend to have low values.