Abstract: Methods, systems, and apparatuses for RFID tags, RFID readers, communications algorithms, and RFID-related applications are described herein. In an aspect of the invention, an RFID tag is capable of storing data, receiving a signal from a reader, determining a response taking into account the tag mode and the data, and transmitting a response to the reader. The data includes a first plurality of bits and a second plurality of bits. The tag mode may be set by a current or a prior command by the reader. Depending on the tag mode, the response may be complete, or the second plurality of bits may be truncated, compressed, or encrypted. In an aspect of the invention, the response includes an implicit indication of whether the response is complete, truncated, encrypted, or compressed. In another aspect of the invention, a command from the reader indicates how many bits should be truncated, compressed, or encrypted.

Abstract: An RFID tag is capable of storing data, receiving a signal from a reader, determining a response taking into account the tag mode and the data, and transmitting a response to the reader. The data includes a first plurality of bits and a second plurality of bits. The tag mode may be set by a current or a prior command by the reader. Depending on the tag mode, the response may be complete, or the second plurality of bits may be truncated, compressed, or encrypted. In an aspect of the invention, the response includes an implicit indication of whether the response is complete, truncated, encrypted, or compressed. In another aspect of the invention, a command from the reader indicates how many bits should be truncated, compressed, or encrypted.

Abstract: Methods, and systems for efficiently reading data stored in an RFID tag memory are described. A delimited read command is issued by an RFID reader, causing a tag to truncate the data read-out process when a delimiter data pattern is detected in the stored data. Upon receipt of a delimited read command, a tag reads data until a delimiter pattern is detected. The tag determines whether the detected pattern is a valid delimiter pattern or a spurious one. If the detected pattern is a valid delimiter, the tag terminates the read process and transmits the data to the reader. The format of the delimiter pattern may be modified based on needs of a particular communications protocol or specific implementations.

Abstract: An electronic article surveillance (EAS) exit portal interrogates a radio frequency identification (RFID) tag affixed to an item that is being removed from the establishment, and attempts to interrogate an EAS pass having an outbound list that stores a set of item identifiers, wherein each item identifier on the outbound list is derived from a RFID tag that is affixed to an item that is authorized for removal. The EAS exit portal detects an unauthorized removal of the item by determining that an item identifier derived from the RFID tag affixed to the item being removed from the establishment is not found on the outbound list of the EAS pass.

Abstract: An RFID tag is capable of storing data, receiving a signal from a reader, determining a response taking into account the tag mode and the data, and transmitting a response to the reader. The data includes a first plurality of bits and a second plurality of bits. The tag mode may be set by a current or a prior command by the reader. Depending on the tag mode, the response may be complete, or the second plurality of bits may be truncated, compressed, or encrypted. In an aspect of the invention, the response includes an implicit indication of whether the response is complete, truncated, encrypted, or compressed. In another aspect of the invention, a command from the reader indicates how many bits should be truncated, compressed, or encrypted.

Abstract: Methods, systems, and apparatuses for RFID tags, RFID readers, communications algorithms, and RFID-related applications are described herein. In an aspect of the invention, an RFID tag is capable of storing data, receiving a signal from a reader, determining a response taking into account the tag mode and the data, and transmitting a response to the reader. The data includes a first plurality of bits and a second plurality of bits. The tag mode may be set by a current or a prior command by the reader. Depending on the tag mode, the response may be complete, or the second plurality of bits may be truncated, compressed, or encrypted. In an aspect of the invention, the response includes an implicit indication of whether the response is complete, truncated, encrypted, or compressed. In another aspect of the invention, a command from the reader indicates how many bits should be truncated, compressed, or encrypted.

Abstract: An encoding method comprises generating a character map of an alphanumeric character string, identifying runs of like character type symbols in sequential positions, and removing the runs of character type symbols from the character map. The center for the center infix run is determined, and the characters of each character type are encoded into binary encoded substrings. A decoding method comprises parsing the one or more run fields in the alphanumeric header to determine a number of characters of each type of a plurality of character types represented in the binary encoded string, generating a character map having a string of character type symbols representing the binary encoded string, including determining a reduced character map, centering the character type symbols for a center infix run about the center of the reduced character map, completing a final character map, and decoding each binary encoded string.

Abstract: Methods and systems for optimizing storage of data items in a memory of a radio frequency identification tag (RFID) are provided. The data structure for optimized storage includes a packed object having a length section including an indication of a number of identifiers in the packed object, an identifier section including a directory of indices representing an identifier for each data item contained within the packed object and a data section encoding a data portion associated with each data item included in the data section.

Abstract: An encoding method comprises generating a character map of an alphanumeric character string, identifying runs of like character type symbols in sequential positions, and removing the runs of character type symbols from the character map. The center for the center infix run is determined, and the characters of each character type are encoded into binary encoded substrings. A decoding method comprises parsing the one or more run fields in the alphanumeric header to determine a number of characters of each type of a plurality of character types represented in the binary encoded string, generating a character map having a string of character type symbols representing the binary encoded string, including determining a reduced character map, centering the character type symbols for a center infix run about the center of the reduced character map, completing a final character map, and decoding each binary encoded string.

Abstract: Systems and methods for optimizing random access retrieval of a requested data item in a radio frequency identification (RFID) tag are provided. During random access retrieval, a first read of a memory bank in the RFID tag is performed. The first read providers a set of identifier indices stored in a packed object in the memory bank of the RFID tag and a length of the packed object. A determination is then made whether a retrieved identifier index represents the requested data item to be retrieved. A second read of the memory bank, accessing the portion of the memory bank including the data items, is then performed. The location of the data item in the packed object may optionally be determined prior to the second read.

Abstract: Methods and systems are provided for improved protection of radio frequency identification tag memory by using two or more “brownout-safe” pointer registers (instead of a single pointer register) that are logically concatenated to form a complete address for the boundary between a locked portion and an unlocked portion of the tag memory. A first pointer is a coarse pointer identifying a block of memory containing the boundary. A second pointer is a fine pointer identifying a specific location within the identified coarse block of memory. The coarse pointer may be a gray-coded or linear pointer. Similarly, the fine pointer may be a gray-coded or linear pointer.

Abstract: A system and method in a radio frequency identification (RFID) tag for writing and erasing user memory. A write command is received at the tag to write data into user memory of the tag. Based on receipt of the write command, a user memory flag in a first memory bank of the tag is set, and the data is written into a second memory bank of the tag. An erase command is received at the tag to erase data stored in the user memory of the tag. Based on receipt of the command to erase, the user memory flag in the first memory bank is cleared, and data stored in the second memory bank is erased.

Abstract: Methods, and systems for efficiently reading data stored in an RFID tag memory are described. A delimited read command is issued by an RFID reader, causing a tag to truncate the data read-out process when a delimiter data pattern is detected in the stored data. Upon receipt of a delimited read command, a tag reads data until a delimiter pattern is detected. The tag determines whether the detected pattern is a valid delimiter pattern or a spurious one. If the detected pattern is a valid delimiter, the tag terminates the read process and transmits the data to the reader. The format of the delimiter pattern may be modified based on needs of a particular communications protocol or specific implementations.

Abstract: An embodiment includes a data structure embodied in a tangible computer readable medium comprising a data section encoding at least one data item and an identification map having a plurality of bits, each bit corresponding to an entry in an external table. Another embodiment includes a system of data structures embodied in a tangible computer readable medium comprising at least one data structure, each data structure encoding at least one data item and an identification map having a plurality of fields indicating the presence of a data item. Another embodiment includes a system of structures comprising a data structure including a previously encoded data item, a deletion list, and an addition list.

Abstract: Methods, systems, and apparatuses for reconstitution of data for failed radio frequency identification (RFID) tags are described. The tag's information is segmented, optionally compressed, and encoded into a plurality of optical representations. Alternatively, or in addition, a portion or all of the tag's information is stored in a non-optical format. Upon failure of a tag read for any reason (e.g., tag failure, reader failure, operator error, environmental reasons, etc.), the data is reconstituted from the optical representations. Alternatively, or in addition, the reconstitution includes incorporating the information stored in a non-optical format.

Abstract: Described are a system and method for verifying a self-authenticating document. First, upon a request for verification of the document, a characteristic digital data “CDD” is extracted from the document. An image of at least a predetermined portion of the document is obtained. The image is divided into a predetermined number of pixel groups and each pixel group includes a plurality of pixels. Pixel characteristic data is determined for each pixel. A pixel group classification data is determined for each pixel group as a function of the pixel characteristics data of at least one pixel in the pixel group. A further CDD for the image is generated as a function of the pixel group classification data and a location of the corresponding pixel group in the image. The document is verified if the CDD is substantially identical to the further CDD.

Abstract: A method for processing information wherein information is received from a plurality of bar code scanners, preferably reading web codes, the source and destination information for the received information is determined and data from the received information is distributed to at least one destination identified by the destination information.

Abstract: Methods and systems are provided for improved protection of radio frequency identification tag memory by using two or more “brownout-safe” pointer registers (instead of a single pointer register) that are logically concatenated to form a complete address for the boundary between a locked portion and an unlocked portion of the tag memory. A first pointer is a coarse pointer identifying a block of memory containing the boundary. A second pointer is a fine pointer identifying a specific location within the identified coarse block of memory. The coarse pointer may be a gray-coded or linear pointer. Similarly, the fine pointer may be a gray-coded or linear pointer.

Abstract: A system and method for encoding scanner signal strength and timing information provided, possibly on multiple signal lines, from a digitizer circuit into a signal that can be transmitted on a single line to a modified decoder. A multiplexing device multiplexes the multiple signals, which can be multi-bit or dual-DBP signals, into a single signal.

Abstract: Methods, systems, and apparatuses for updating pointers in memory are described. A device can include pointer logic and a memory that stores a memory pointer. The pointer logic can increment or decrement the memory pointer according to Gray code. The device can increment or decrement the memory pointer in response to a pointer change command and can be configured to first verify a password associated with the command. The device can send an acknowledgement that the command has been received and/or executed. Multiple increments or decrements of the memory pointer can occur in response to a pointer change command configured as a single multiple-increment-or-decrement command or as multiple single-increment-or-decrement change commands. The device can determine an updated value for each of a first memory pointer portion and a second memory pointer portion of the memory pointer.