An Overview of the ISO RFID Data Protocol & Library Applications Paul Chartier Project Editor...

An Overview of the ISO RFID Data Protocol & Library Applications

Paul Chartier

Project Editor ISO/IEC 15961 & 15962

June 2006

Libraries & ISO RFID Standards June 2006Copyright praxis consultants,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 SystemThe Generic Model

RFIDTagAir interfaceApplication protocolData

content

APPLICATION


RFID Standards Types of Standard

Technology - air interfacedefines what it does

Conformance & Performancecompares actual devices with standards

“Middleware” protocolshow data and instructions are processed

Data contenthow business data is supported

Applicationsmaking it work for a specific sector


ISO RFID StandardsAir 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 ArchitectureISO/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

SYST EM INFO

UNIQUE T AG ID

includes Application Fam ily Id Data Form at

optional

NUM BER OF BLOCKS

BLOCK SIZE

Each block can beaddressed individuallyand blocks can belocked selectively

T his area containsall the application dataconcatenated inone sequence


An RFID Implementation Based Only on the Air interface

Interrogator(Reader /Encoder)

An

ten

na

RF T ag

Air InterfaceCom m ands

AirInterfaceResponses

ApplicationSoftware

ISO/IEC 18000

AIR INT ERFACERESPONSES

AIR INT ERFACECOMMANDS


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 ProtocolPositioning ISO/IEC 15961 & 15962

Interrogator(Reader /Encoder)

An

ten

na

RF T ag

Air InterfaceCom m ands

AirInterfaceResponses

ApplicationSoftware

ISO/IEC 18000

APPLICAT IONCOM M ANDS

APPLICAT IONRESPONSES

ISO/IEC15961

Data ProtocolProcessor

Encoder

Decoder

Command /Response

UnitLogicalM emory

TagDriver(s)

ISO/IEC15962

ISO/IEC 15962


RFID Data ProtocolOverview

In terrogatorReader / Encoder

Antenna

Air InterfaceCom m ands Air Interface

Responses

Application Software

• The Data Protocol fills a gap in communications


Antenna


Responses


Data ProtocolApplication Interface

ISO/IEC 15961

• Business issues are addressed by the Application Interface

• This generates commands and processes responses Interrogator

Reader / Encoder

Antenna


Responses


ApplicationCom m ands


ISO/IEC 15961


Antenna


Responses


ApplicationCom m ands Application

Responses


ISO/IEC 15961

• The encoding rules convert the data in the commands into efficient encoding on the RF tag


Antenna


Responses



Responses


ISO/IEC 15961

Data ProtocolEncoding RulesISO/IEC 15962


RFID Data ProtocolISO/IEC 15961 Application Interface


Antenna


Responses



Responses


ISO/IEC 15961


Application Interface

Format O bject Identifier

System Information

C ommand & R esponseApplication 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

SYST EM INFO

UNIQUE T AG ID

includes Application Fam ily Id Data Form at

optional

NUM BER OF BLOCKS

BLOCK SIZE

Each block can beaddressed individuallyand blocks can belocked selectively

T his area containsall the application dataconcatenated inone sequence


ISO/IEC Air Interface & Data ProtocolSystem 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 ProtocolSystem 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 AFIA Tool for Efficient Communications


The AFI: A Powerful Tool to Select Only Relevant Tags

Reader


RFID Data ProtocolISO/IEC 15962 Data Encoding Rules

InterrogatorReader / Encoder

Antenna

Air InterfaceCommands Air Interface

Responses


ApplicationCommands Application

Responses


ISO/IEC 15961


InterrogatorReader / Encoder

Data Protocol Processor

D ata C om pac to r

D ata F o rm atte r

Log ical Mem ory

T ag Driver

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 15962Data 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 15962Logical 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)

LogicalM emory


RFID Data ProtocolRevisions 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 15961Data 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 CommunityData 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 CommunityData 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

[email protected]

An Overview of the ISO RFID Data Protocol & Library Applications Paul Chartier Project Editor...

Documents

Transcript of An Overview of the ISO RFID Data Protocol & Library Applications Paul Chartier Project Editor...