ISO/IEC 18000 - RFID Air Interface Standards

ISO/IEC 18000 is a series of standards being created by ISO/IEC/JTC 1/SC31/WG4/SG3. They are creating RFID air interface standards for the item identification world.

ISO/IEC 18000 has been published. You can visit the ISO web site to get more details and order the documents or you can get them from your local National Body. Visit ISO.

The ISO/IEC 18000 series of standards are currently in revision to make them more up-to-date and bring in new information. Each of the parts are at different stages (see below). The updates are in one main area but also include other things as detailed below:

• A revision to all the parts of 18000 will include fixes to the standards based on actual issues discovered during the use of the standards along with the addition of the capabilities to use batteries and sensors with the existing technologies.

For more information on this and any other RFID standard, contact steve@hightechaid.com

The standard is a seven part (currently) standard with the following parts:

ISO/IEC 18000 Information Technology AIDC Techniques-RFID for Item Management - Air Interface

• 18000-1 Part 1 – Generic Parameters for the Air Interface for Globally Accepted Frequencies

• 18000-2 Part 2 – Parameters for Air Interface Communications below 135 kHz

• 18000-3 Part 3 – Parameters for Air Interface Communications at 13.56 MHz

• 18000-4 Part 4 – Parameters for Air Interface Communications at 2.45 GHz

• 18000-5 Part 5 – Parameters for Air Interface Communications at 5.8 GHz (Withdrawn)

• 18000-6 Part 6 – Parameters for Air Interface Communications at 860 to 960 MHz

• 18000-7 Part 7 – Parameters for Air Interface Communications at 433 MHz

As can be seen, each of these parts deals with a different aspect of RFID. The first part is the defining document that explains how the standard works and the rest are divided by frequency.

18000-1 Part 1 – Generic Parameters for the Air Interface for Globally Accepted Frequencies

Scope

The Scope of this Standard is to describe the Reference Architecture for Radio Frequency Identification for Item Management and to establish the Parameters that shall be determined in any Standardised Air Interface Definition in the ISO 18000 series. The subsequent parts of this Standard providing specific values for Air Interface Definition Parameters shall then, once approved, provide the frequency specific values and value ranges from which compliance to (or non compliance with) this Standard can be established.

This Standard limits its Scope to transactions and data exchanges across the air interface at Reference Point Delta. (See Section 4, fig 1. below). The means of generating and managing such transactions, other than a requirement to achieve the transactional performance determined within this Standard, are outside the scope of this Standard, as is the definition or specification of any supporting hardware, firmware, software or associated equipments.

Standardisation of other Reference Points are outside the scope of this Standard. (See fig 1. Below)
This standard is an enabling standard which supports and promotes several RFID implementations without making conclusions about the relative technical merits of any available option for any possible application.

18000-2 Part 2 – Parameters for Air Interface Communications below 135 kHz

Scope

 This document specifies:

• The physical layer that shall be used for communication between the interrogator and the tag. The interrogator shall be capable to communicate with tags of both Type A (FDX) and Type B (HDX).

• The protocol and the commands

• The method to detect and communicate with one tag among several tags ("anticollision")

Tag types

This standard specifies two types of tags: Type A (FDX) and Type B (HDX).

• These two types differ only by their physical layer. Both types support the same anti-collision and protocol.

• FDX tags are permanently powered by the interrogator, including during the tag-to-interrogator transmission. They operate at 125kHz.

• HDX tags are powered by the interrogator, except during the tag-to-interrogator transmission. They operate at 134.2kHz.

• An optional anticollision is described in the informative annex D.

Compliance rules

Tag

• To claim compliance with this standard, a tag shall be of either Type A or B.

NOTE Nothing in this standard prevents a tag to be of both types, although for technical reasons, it is unlikely that such tags are ever marketed.

Interrogator

• To claim compliance with this standard, an interrogator shall support both Types A and B.

• Depending on the application, it may be configured as Type A only, Type B only or Types A and B.

• When configured in Types A and B, and when in the Inventory phase, the interrogator shall alternate between Type A and Type B interrogation. See Annex C.

HTA Comment:

Two type A and B, interrogator must support both. Frequency is slightly different and they are Type A (Full Duplex) and Type B (Half Duplex).

18000-3 Part 3 – Parameters for Air Interface Communications at 13.56 MHz

Scope

The scope of this Standard is to provide Physical Layer, Collision management System and Protocol Values for RFID Systems for Item Identification operating at 13.56 MHz in accordance with the requirements of ISO 18000-1

This Standard provides Parameter Value for each MODE determined in the Requirements Clause below.

In this version of the Standard, 3 non contending MODES are defined.

The MODES are NOT interoperable

The MODES, whilst not interoperable, are non contending.

HTA Comment:

Three Modes. Mode 1 is based on 15693 with additions/changes to better suit the Item management market and improve the compatibility between vendors.

The Interrogator to Tag data rate is 1.65 kbps (fc/8192) or 26.48 kbps (fc/512)

The Tag to Interrogator data rate is 26.48 kbps (fc/512). The protocol extension has a precursor data rate ~ 52.97 kbps (fc/256) and a main reply data rate ~105.94 kbps (fc/128).

Mode 2 is a high speed interface.

The Interrogator to Tag data rate is 423.75 kbps

The Tag to Interrogator data rate is 105.9375 kbps on each of 8 channels

Mode 3 is a high speed interface with two options. Option 1 is ASK based, option 2 is PJM based. Both use the 18000-6C command structure to be compatible with EPCglobal

In option 1 the Interrogator to Tag data rate is 26.7 kbit/s to 100 kbit/s (assuming equally probable data), in option 2 it is 212 kbit/s

In option 1 the Tag to Interrogator data rate is FM0, 424 kbit/s or 848 kbit/s; Sub-carrier modulated, 53 kbit/s to 212 kbit/s, in option 2 it is 105.9375 kbps on each of 8 channels

18000-4 Part 4 – Parameters for Air Interface Communications at 2.45 GHz

Scope

1.1 Frequency

This standard is intended to address RFID devices operating in the 2450 MHz Industrial, Scientific and Medical (ISM) frequency band.

1.1.1 Interface Definitions

This standard supports a standard API (ISO/IEC 18000-1) and standard air interface implementations for wireless, non-contact information system equipment for Item Management applications. Typical applications operate at ranges greater than one meter.

HTA Comment:

Two modes. Mode 1 is a passive tag, mode 2 is a battery assisted, tag talks first tag.

MODE1: PASSIVE BACKSCATTER RFID SYSTEM

The FHSS backscatter option or the narrow band operation RFID system shall include an interrogator that runs the FHSS backscatter option 1 RFID protocol or in narrow band operation, as well as one or more tags within the interrogation zone

MODE 2: LONG RANGE HIGH DATA-RATE RFID SYSTEM

This clause describes a RFID system, offering a gross data rate up to 384 kbps at the air interface in case of Read/Write (R/W) tag. In case of Read Only (R/O) tag the data rate is 76.8 kbps. The tag is battery assisted but back scattering. By using of battery powered tags such a system is well designed for long-range RFID applications.

This air interface description does not explicit claim for battery assistance in the tag, also real passive tags or tags for mixed operation are conceivably.

18000-5 Part 5 – Parameters for Air Interface Communications at 5.8 GHz

Scope

The scope of this Standard is to provide Physical Layer, Anti collision System and Protocol Values for RFID Systems for Item Identification operating at 5.8 –5.9 GHz in accordance with the requirements of ISO 18000-1

This part of the standard was abandoned due to insufficient global interest

18000-6 Part 6 – Parameters for Air Interface Communications at 860 to 960 MHz

Scope

This standard describes:

• the physical interactions between the interrogator and the tag

• the protocols and the commands,

• the collision arbitration schemes

HTA Comment:

Four types, Types A, B, C and D.

For the forward link, Type A uses Pulse interval encoding at 33 kbit/s, Type B uses bi-phase modulation and Manchester encoding at 10 or 40 kbit/s.

For the collision arbitration, Type A uses an Aloha-based mechanism, Type B uses an adaptive binary tree mechanism.

Both types uses the same bi-phase space FM0 return link encoding, at 40 or 160 kbit/s. 

Type C is meant to be identical to EPCglobal's UHF Gen 2 specification.

In the forward link it uses Pulse Interval Encoding at 26.7 to 128 kbit/s and in the reverse it uses Baseband FM0 or Miller-modulated subcarrier return link at FM0: 40 kbps to 640 kbps, or Subcarrier modulated: 5 kbps to 320 kbps.

Type D is a Tag Talks Only After Listen. technology.  this is similar to a Tag Talks First but it waits until it is sure tere is no other traffic on the channel. This prevents the Tag from talking all the time and blocking other types of tags from communicating.

18000-7 Part 7 – Parameters for Air Interface Communications at 433 MHz

Scope

1.1 Frequency

Information Technology AIDC Techniques - RFID for Item Management - Air Interface, Part 7 – Parameters for an Active RFID Air Interface Communications at 433 MHz. This standard is intended to address RFID devices operating in the 433 MHz frequency band.

1.1.1 Interface Definitions.

This standard supports a standard API (ISO/IEC 18000-1) and standard air interface implementations for wireless, non-contact information system equipment for Item Management applications. Typical applications operate at ranges greater than one meter.

1.1.1.1 RFID System Definition

The RFID system shall include a host system and RFID equipment (interrogator and tags). The host system runs an application program, which controls interfaces with the RFID. The RFID equipment shall be composed of two principal components: tags and interrogators. The tag is intended for attachment to an item, which a user wishes to manage. It is capable of storing a tag ID number and other data regarding the tag or item and of communicating this information to the interrogator. The interrogator is a device, which communicates to tags in its field of view. Additionally, the interrogator can use its transmitted RF carrier to power the tag. Systems, which rely on the transmitted interrogator carrier for powering the tag, are typically referred to as passive tag systems. The interrogator controls the protocol, reads information from the tag, directs the tag to store data in some cases, and ensures message delivery and validity.

1.1.1.2 Minimum Features

RFID systems defined by this standard provide the following minimum features:

• Identify tag in range

• Read data

• Write data or handle read only systems gracefully

• Selection by group or address

• Graceful handling of multiple tags in the field of view

• Error detection

HTA Comment:

One Mode, long distance capability, active tag system

• RFID Standards from SC31

• An explanation of how ISO standardization works

• RFID Standards (Two Presentations - Jan 2002, April 2002)

• Standards Update

(Data Correct as of Nov 21, 2008)