An Overview of the ISO RFID Data Protocol & Library Applications Paul Chartier Project Editor ISO/IEC 15961 & 15962 June 2006

A Basic Question: “Why Standards?” BSI defines standardisation as the process of “establishing and applying an agreed set of solutions intended for repeated application, directed at benefits for stakeholders and balancing their diverse interests.” The library community has developed and adopted a broad variety of standards - but not yet for RFID

Some Benefits of RFID Standards Specifies the rules for components to be fit for purpose Establishes interoperability of RFID devices Establishes compatibility between library systems but still supports flexible applications Avoids systems clash with other applications - given that RFID tags on library items move around the community Stakes a claim for library systems so that other RFID systems do not corrupt library applications Provides a better chance of migration as technology improvements are made

RFID System The Generic Model Tag Data content Application protocol Air interface APPLICATION

RFID Standards Types of Standard Technology - air interface defines what it does Conformance & Performance compares actual devices with standards “Middleware” protocols how data and instructions are processed Data content how business data is supported Applications making it work for a specific sector

ISO RFID Standards Air Interface Standards Various aspects can be covered, but key are: The air interface: frequency, modulation, bit encoding Anticollision the ability to almost simultaneously address a number of tags unambiguously not always a requirement Commands and responses that address memory in terms of blocks (or words, or pages)

Tag Architecture ISO/IEC 18000-3 Mode 1 Single memory Can emulate a UII by placing this first Separate TID and System Info (inc AFI) Block size & number of blocks can vary

An RFID Implementation Based Only on the Air interface

Implications of the Application Working at the Air interface Level Memory map has to be pre-defined for encoding New data requires a new “message” or memory map rule Need to understand the memory map to read data Need to use RFID air interface commands Data might not be encoded most efficiently Data might not be encoded most efficiently, especially variable length and optional data

APPLICATION PROTOCOL STANDARDS Data Protocol The Data Protocol addresses data handling between the application and the RF tag ISO/IEC 15961 Data protocol - application interface: defines the application commands and responses uses object identifiers to define all data types ISO/IEC 15962 Data protocol - data encoding rules efficient encoding of object identifiers common data compaction

RFID Data Protocol Positioning ISO/IEC 15961 & 15962

RFID Data Protocol Overview • The Data Protocol fills a gap in communications • Business issues are addressed by the Application Interface • This generates commands and processes responses • The encoding rules convert the data in the commands into efficient encoding on the RF tag

RFID Data Protocol ISO/IEC 15961 Application Interface Application Family Data Format Access Method Generated based on ASN.1 Abstract syntax Transfer encoding

RFID Data Protocol ISO/IEC 15961 Object Identifiers Object identifiers used for selective read / write Based on ISO/IEC 9834-1 established rules and structures ISO/IEC 9834-1 allows systems to define objects to any level of granularity - just need an object ID A typical object identifier: 1 0 15961 127 13 The Hierarchical structure ensures uniqueness of objects Therefore, possible to encode different data, including closed system objects with no risk of corruption Extension techniques make the system totally expandable

ISO/IEC JTC1/SC31 Logical Tag Structure

ISO/IEC Air Interface & Data Protocol System Information This provides a protocol level - not data - method for managing the interface between application and RF tag, and includes: Application Family: to enable a subset of RF tags to be in the communication channel Data Format: to specify the interpretative nature of the encoded bytes on the RF tag Access Method: to create a logical structure of the bytes encoded on the RF tag

ISO/IEC Air Interface & Data Protocol System Information: Application Family There is a real need to manage the transactions across the air interface with large population of tags where there is a risk of different types of tag being present To be compatible with smart card rules (SC17), RFID for Item Management has to co-manage some codes Application Family codes are allocated to focus on a meaningful subset within the system, thus excluding RF tags from other systems

The AFI A Tool for Efficient Communications

The AFI: A Powerful Tool to Select Only Relevant Tags Reader

RFID Data Protocol ISO/IEC 15962 Data Encoding Rules Consider this like a bar code encoder, but common to many RF tags Each different air interface has its own Tag Driver, determining precise mapping rules

ISO/IEC 15962 Data Compaction Schemes The ISO/IEC 15962 process looks, on a case by case basis of each data object, at the byte encoding on the RF tag It selects the most efficient encoding scheme from the alternatives (the most efficient scheme is at the top of this list) Integer: encodes number as binary Numeric: 4 bits per digit 5-bit: uppercase alphabetic 6-bit: uppercase alphabetic, numeric, etc 7-bit: all ISO 646 (US ASCII) Octet: unaltered 8-bit It also preserves user-defined data and supports UTF-8 for international character sets

ISO/IEC 15962 Logical Memory A software representation of the RF tag memory Structured by extracting the system information from the RF tag Structure width = block (or codeword) size length = number of blocks (or codewords)

RFID Data Protocol Revisions to ISO/IEC 15961 & 15962 15961-1: 15961 (pub October 2004) needs to be simplified with respect to the data constructs topics New application commands for 18000-6C and sensors 15961-2: Rules for new Registration Authority for AFIs and other data constructs 15961-3: Specification of data constructs 15962: New encoding and data mapping processes for 18000-6C and sensors

ISO/IEC 15961 Data Constructs Application Family Identifier (AFI): Used to manage selection across air interface Data Format: A “shorthand” code to truncate the encoding of long Object Identifiers Object Identifier for UII - Register of key traceability codes Object Identifier for other item-attendant data - Register of OID structure for other data

Library Community Data Constructs Process - with SC31 EDItEUR has made initial request for registration, with the understanding that the application was incomplete The assignment of data constructs for libraries is accepted Additional information required for: Object Identifier for primary code Object Identifier structure for additional data objects JTC1/SC31 WG4 has a procedure that can approve the registration and assign the AFI and Data Format The data constructs will be published and maintained on the web

Library Community Data Constructs - within the Sector Define data objects (e.g. ISIL, ISBN) Specify data objects format (e.g. alphanumeric, numeric, UTF-8) fixed or variable length fixed or maximum length Specify relative-OID value Extend and revise with no constraints from SC31/WG4

Thank you for your attention paul.chartier@praxisconsultants.co.uk