ISO/IEC 18000-4:2008

INTERNATIONAL ISO/IEC
STANDARD 18000-4
Second edition
2008-09-01

Information technology — Radio
frequency identification for item
management —
Part 4:
Parameters for air interface
communications at 2,45 GHz
Technologies de l'information — Identification par radiofréquence
(RFID) pour la gestion d'objets —
Partie 4: Paramètres de communications d'une interface d'air
à 2,45 GHz




Reference number
ISO/IEC 18000-4:2008(E)
©
ISO/IEC 2008

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ISO/IEC 18000-4:2008(E)
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©  ISO/IEC 2008
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ISO/IEC 18000-4:2008(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Symbols and abbreviated terms . 2
5 2,45 GHz RFID protocols that support this part of ISO/IEC 18000. 3
5.1 General. 3
5.1.1 Protocols . 3
5.1.2 Frequency. 3
5.1.3 Tag identification number. 4
5.1.4 Potential interference . 4
5.2 MODE 1: Passive backscatter RFID system . 4
5.2.1 MODE 1: Physical and media access control (MAC) parameters. 5
5.2.2 Physical layer and data coding . 10
5.2.3 Protocol and collision arbitration . 20
5.3 MODE 2: Long range high data rate RFID system. 47
5.3.1 MODE 2: Physical and media access control (MAC) parameters. 47
5.3.2 Modulation and coding. 52
5.3.3 General system description. 55
5.3.4 Frame structure. 55
5.3.5 CCC 6.2.5 Channel coding and sequences. 77
5.3.6 Command set for the command slot channel: CS-CH (only for R/W-tag). 78
6 Table of characteristic differences between the modes specified in this part of ISO/IEC
18000 . 82
Annex A (informative) Mode 1: Memory Map. 83
A.1 Tag memory map . 83
A.2 Unique identifier. 83
A.3 Manufacturer ID and tag hardware. 85
A.4 Tag Memory layout . 86
A.5 Application (USER) memory. 88
Annex B (informative) Mode 1: CRC. 89
B.1 Interrogator to tag and tag to interrogator CRC-16. 89
B.2 CRC calculation examples. 90
Annex C (normative) Mode 2: Memory Map . 93
C.1 Tag Memory map . 93
C.2 Tag Serial number – UserTagID . 94
C.3 Tag manufacturer’s identifiers – MfrTagID . 95
Annex D (informative) Mode 2: CRC. 96
D.1 Cyclic redundancy check (CRC) . 96
D.2 CRC calculation example. 96
Bibliography . 98

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ISO/IEC 18000-4:2008(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
ISO/IEC 18000-4 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology
Subcommittee SC 31, Automatic identification and data capture techniques.
This second edition cancels and replaces the first edition (ISO/IEC 18000-4:2004), which has been technically
revised.
ISO/IEC 18000 consists of the following parts, under the general title Information technology — Radio
frequency identification for item management:
⎯ Part 1: Reference architecture and definition of parameters to be standardized
⎯ Part 2: Parameters for air interface communications below 135 kHz
⎯ Part 3: Parameters for air interface communications at 13,56 MHz
⎯ Part 4: Parameters for air interface communications at 2,45 GHz
⎯ Part 6: Parameters for air interface communications at 860 MHz to 960 MHz
⎯ Part 7: Parameters for active air interface communications at 433 MHz
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ISO/IEC 18000-4:2008(E)
Introduction
This part of ISO/IEC 18000 is one of a series of International Standards and Technical Reports developed by
ISO/IEC JTC 1/SC 31, WG 4 for the identification of items (Item Management) using radio frequency
identification (RFID) technology.
This part of ISO/IEC 18000 defines the 2,45 GHz protocols that support ISO/IEC 18000-1. Each of the specific
physical/data link configurations is defined in a separate sub-clause. The configuration descriptions include a
Physical Layer and a Data Link Layer.
The International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC)
draw attention to the fact that it is claimed that compliance with this document may involve the use of patents
concerning radio-frequency identification technology given in all parts of the document and especially in 5.2
and 5.3.
ISO and IEC take no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured the ISO and IEC that they are willing to negotiate licences
under reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this
respect, the statements of the holders of these patent rights are registered with ISO and IEC. Information may
be obtained from the following companies.
Contact details Patent number
Intermec IP Corporation US 5,030,807
Legal Department US 5,521,601
Phyllis T.Turner-Brim, Esq. US 5,550,547
6001 36th Ave, W US 5,673,037
Everett, Washington 98203, US 5,777,561
USA US 5,828,318
Tel.: +1(425)625-2480 US 5,828,693
Fax: +1(425)501-6587 US 5,850,181
Email: phyllis.turnerbrim@intermec.com US 5,942,987
US 5,995,019
NXP B.V. CN02811230
Intellectual Property & Licensing JP 03-502778;
Mr. Harald Röggla US6,961,829B
Gutheil-Schoder-Gasse 8-12 EP02735725.0
A-1102 Vienna
Austria
Tel.: +43(1)60870-1469
Fax: +43(1)60870-1101
Email: harald.roeggla@nxp.com
Siemens Aktiengesellschaft, US 7289458
CT IP L&T EP 1415263
Hans Joerg Mueller DE 10137247
Otto-Hahn-Ring 6 US 6944240
D-81739 Munich DE 19962458
Germany EP 1240720
Tel: +49(89)636 82628
Fax: +49(89)636 81855
Email: hans-joerg.mueller@siemens.com
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ISO/IEC 18000-4:2008(E)
Contact details Patent number
Zebra Technologies Corporation, US 5519381
Legal Department, US 5726630
Mr. Eric McAlpine, IP Counsel, EP 0598624
333 Corporate Woods Parkway, EP 0789254
Vernon Hills, Illinois 60061-3109, EP 0789253
USA EP 01117486.9
Tel: +1(847)793-5640 US 5680459
Fax: +1(847)955-4514 US 6198381
Email: emcalpine@zebra.com JP 10-272945

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights other than those identified above. ISO and IEC shall not be held responsible for identifying any or all
such patent rights.

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INTERNATIONAL STANDARD ISO/IEC 18000-4:2008(E)

Information technology — Radio frequency identification
for item management —
Part 4:
Parameters for air interface communications at 2,45 GHz
1 Scope
This part of ISO/IEC 18000 defines the air interface for radio frequency identification (RFID) devices operating
in the 2,45 GHz Industrial, Scientific, and Medical (ISM) band used in item management applications. This
part of ISO/IEC 18000 provides a common technical specification for RFID devices that can be used by ISO
committees developing RFID application standards. This part of ISO/IEC 18000 is intended to allow for
compatibility and to encourage inter-operability of products for the growing RFID market in the international
marketplace. This part of ISO/IEC 18000 defines the forward and return link parameters for technical
attributes including, but not limited to, operating frequency, operating channel accuracy, occupied channel
bandwidth, maximum equivalent isotropically radiated power (EIRP), spurious emissions, modulation, duty
cycle, data coding, bit rate, bit rate accuracy, bit transmission order, and where appropriate operating
channels, frequency hop rate, hop sequence, spreading sequence, and chip rate. This part of ISO/IEC 18000
further defines the communications protocol used in the air interface.
This part of ISO/IEC 18000 contains two modes. The first is a passive tag operating as an interrogator talks
first and the second is a battery-assisted tag operating as a tag talks first. The detailed technical differences
between the modes are shown in the parameter tables.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 7816-6, Identification cards — Integrated circuit cards — Part 6: Interindustry data elements for
interchange
ISO/IEC 15963, Information technology — Radio frequency identification for item management — Unique
identification for RF tags
ISO/IEC 18000-1, Information technology — Radio frequency identification for item management — Part 1:
Reference architecture and definition of parameters to be standardized
ISO/IEC TR 18047-4, Information technology — Radio frequency identification device conformance test
methods — Part 4: Test methods for air interface communications at 2,45 GHz
ISO/IEC 19762 (all parts), Information technology — Automatic identification and data capture (AIDC)
techniques — Harmonized vocabulary
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ISO/IEC 18000-4:2008(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 19762 (all parts) apply.
4 Symbols and abbreviated terms
Cht Carrier high level tolerance
Clt Carrier low level tolerance
f base frequency of the bit rate of Manchester code without bit changes
bitrate
f frequency of operating field (carrier frequency)
c
FHSS Frequency Hopping Spread Spectrum
M Modulation
Ma Modulation overshoot
Mb Modulation undershoot
Mlt Modulation lower tolerance
Mut Modulation upper tolerance
Tbmf Manchester fall time
Tbmr Manchester rise time
Tcf carrier fall time
Tcr carrier rise time
Tcs carrier steady time
Tf fall time
Tfhf carrier FHSS fall time
Tfhr carrier FHSS rise time
Tfhs carrier FHSS steady time
Tflb forward link bit time
Tr rise time
Trlb return link bit time
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ISO/IEC 18000-4:2008(E)
5 2,45 GHz RFID protocols that support this part of ISO/IEC 18000
5.1 General
5.1.1 Protocols
Clause 5 defines the ISO/IEC 18000-4 2,45 GHz RFID command/data level communication protocols. These
protocols facilitate communication between compliant tag and compliant interrogator. The timing parameters
and signal characteristics for the protocols are defined in the physical link specifications in each mode.
5.1.2 Frequency
This part of ISO/IEC 18000 is intended to address RFID devices operating in the 2 450 MHz Industrial,
Scientific and Medical (ISM) frequency band.
5.1.2.1 Interface definitions
This part of ISO/IEC 18000 supports standard parameters as described in 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.
5.1.2.1.1 RFID system definition
The radio-frequency identification (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.
5.1.2.1.2 Minimum features
RFID systems defined by this part of ISO/IEC 18000 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.
5.1.2.1.3 Conformance
To claim conformance with this part of ISO/IEC 18000, an RFID system shall comply with one of the
physical/data link implementations described in 5.2 and 5.3.
The rules for RFID device conformity evaluation are given in ISO/IEC TR 18047-4.
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ISO/IEC 18000-4:2008(E)
5.1.3 Tag identification number
A tag identification number shall be included in commands directed to a specific tag unless the protocol
provides other means like TTF (Tag Talks First) protocols. This part of ISO/IEC 18000 mandates that each tag
shall include a manufacturer’s tag identification number as defined in Annex A for mode 1 and in Annex C for
mode 2.
A separate User Tag Identification is not mandatory, but is an option. When a UserTagID is used, it shall
consist of the number of bytes required by the user application. This number and other application data shall
be accessed as user data fields on the tag. These fields can be accessed via the API using the driver’s field
name resolution mechanism. The UserTagID is a user-defined tag identifier and is not necessarily unique.
5.1.4 Potential interference
Standards developers have a duty to ensure that no "significant interference" exists between Standardized
modes. "Significant Interference" exists if a system of one Standardized mode (working within the most
widespread regulated power emissions) is likely to impede the successful operation of a system of another
Standardized mode (working within the most widespread regulated power emissions), in likely expected
operating situations.
Marginal measurable interference that does not impede operation in likely expected operating situations, or
that could be avoided by simple and inexpensive design improvement, shall not be considered cause to reject
a mode.
• Therefore, TTF modes are clearly identified as such in this part of ISO/IEC 18000.
• Therefore, installers of RFID systems are advised that they should make best efforts to be a good
neighbour in installing any systems, bearing in mind that there may be other systems sharing the same
bandwidth and are advised to take precautions to minimise interference to other systems. Installers are
equally advised to be prepared to handle interference within the bandwidth from other users up to
transmission powers permitted by local regulations.
5.2 MODE 1: 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.
When placed in the RF field of an interrogator, the tag shall begin to power up. If the field is adequate, the tag
shall execute a power-on reset and shall be ready to receive commands. Each command shall begin with a
preamble and start delimiters that, taken together, enable the tag to perform clock and data recovery on the
incoming signal. Data to and from the tag is checked for errors using a Cyclic Redundancy Code (CRC).
Therefore, CRC fields are present in all interrogator interrogations and in all tag responses. Additional data
protection is provided by Manchester encoding on the forward (interrogator to tag link) and FM0 encoding on
the return (tag to interrogator) link.
By using the FHSS backscatter option 1 RFID command set or in narrow band operation, the interrogator can
execute a number of functions on tags in its field. For example, the interrogator can send a command
sequence, which allows it to identify multiple tags simultaneously in its RF field. Alternately, it can select a
subset of the tags in the field based on tag memory contents. It can also read data stored on a tag in its field,
as well as write or lock data to such a tag.
The description of the RFID tag command set in the following clause shall provide detail regarding the
command field and return data/acknowledgement fields, if any. In addition, it shall cover additional high-level
elements of the FHSS backscatter option RFID protocol, including how the multiple item identification
algorithm works and byte ordering requirements. The more general aspects of the protocol (preambles,
CRC-16, etc.) are covered in detail in 5.2.2.7.
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ISO/IEC 18000-4:2008(E)
This portion of the International Standard describes a passive backscatter RFID system that supports the
following system capabilities:
System protocol
• Identify and communicate with multiple tags in the field
• Select a subgroup of tags to identify or communicate with based on information that the user has
stored in the tag
• Read from and write or rewrite data many times to individual tags
• User controlled permanent lock memory
Data integrity protection
• Manchester bit-wise encoding and CRC-16 packet-level protection is applied to the forward link
(interrogator-to-tag) data.
• FM0 bit-wise encoding and CRC-16 packet-level protection is applied to the return link (tag-to-
interrogator) data.
In this RFID system, interrogators both power and communicate with the tags that are within their range. Tags
receive data as on-off key amplitude modulation of the power/data signal from the interrogator. During the
time that the tag communicates back to the interrogator, the interrogator broadcasts a steady radio frequency
power level, and the tag modulates the impedance of its radio frequency load attached to the tag antenna
terminals. The interrogator then receives the data back from the tag as a variation in reflection of its
transmitted power.
5.2.1 MODE 1: Physical and media access control (MAC) parameters
5.2.1.1 MODE 1: Interrogator to tag link
Table 1 — Physical link specifications - forward link
Ref. Parameter name Description
M1-Int:1: Operating Frequency Range As permitted by local radio regulations in the band from 2 400 to
2 483,5 MHz.
M1-Int: 1a Default Operating Frequency 2 450 MHz
M1-Int: 1b Operating Channels As required by local radio regulations.
As an example in the US 79 channels from 2 422,5 to 2 461,5 in 0,5 MHz
increments may be used.
M1-Int: 1c Operating Frequency Maximum tolerance is ±50 ppm, however local tolerance may apply in case
Accuracy required by local regulations.
M1-Int: 1d Frequency Hop Rate The hop rate, if applicable, is determined by each country’s regulatory
authority in which the system is being operated.
As an example, within the US the maximum time at any frequency as set by
FCC, clause 15,247 of FCC part 15 is 0,4 s.
M1-Int: 1e Frequency Hop Sequences Pseudo-random hopping patterns uniformly utilising the designated frequency
band.
M1-Int: 2 Occupied Channel Maximum 0,5 MHz. Bandwidth specification according definition of local radio
Bandwidth regulations.
As an example, within the US the 20 dB bandwidth is regulated by reference
document 1.2.2, clause 15.247 of FCC part 15.
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ISO/IEC 18000-4:2008(E)
Table 1 (continued)
Ref. Parameter name Description
M1-Int: 3 Interrogator Transmit The maximum output power is regulated by each country’s regulatory authority
Maximum EIRP in which the system is being operated.
As an example, within the US reference document, clause 15.247 of FCC part
15 at the time of drafting of this part of ISO/IEC 18000, has as a maximum 30
dBm output from the interrogator, and 4W (36 dBm) EIRP from the interrogator
transmit antenna.
As an example, within the Japan reference document, for a fixed frequency
(i.e. narrowband) mode of operation in the ISM band the system may operate
as "licensed" providing 300 mW of conductive power into a directional antenna
of gain below 20 dBi. Channel definition under FHSS "unlicensed" operation
may be used for this mode of operation.
M1-Int: 4 Interrogator Spurious Covered in M1-Int: 4a and M1-Int 4b
Emissions
M1-Int: 4a Interrogator Transmit not applicable
Spurious Emissions, In
Band (for Spread Spectrum
systems)
M1-Int: 4b Interrogator Transmit The interrogator shall transmit in conformance with spurious emissions
Spurious Emissions, Out of requirements defined by the country’s regulatory authority within which the
Band system is operated.
As an example, within the US reference, clause 15.205 and 15.209 of FCC
part 15 sets the limit at the time of drafting of this document at 500 µV/m @ 3 m
M1-Int: 5 Interrogator Transmitter Communication carrier: ASK
Spectrum Mask
M1-Int: 6 Timing Covered in M1-Int: 6a to M1-Int 6d
M1-Int: 6a Transmit to Receive Turn See 5.2.2.9.2
Around Time
M1-Int: 6b Receive to Transmit Turn As determined by the communication protocol – refer to tag 6a.
Around Time
M1-Int: 6c Dwell time or Interrogator < 5 % of bit period
Transmit Power-On Ramp
M1-Int: 6d Decay time or Interrogator < 5 % of bit period
Transmit Power-Down
Ramp
M1-Int: 7 Modulation ASK. Details are described in 5.2.2.4
M1-Int: 7a Spreading sequence (for Not applicable
Direct Sequence Spread
Spectrum [DSSS] systems)
M1-Int 7b Chip Rate (for Spread Not applicable
Spectrum systems)
M1-Int 7c Chip Rate Accuracy (for Not applicable
Spread Spectrum systems)
M1-Int 7d Modulation Index 99 %. For details see 5.2.2.4.1
M1-Int 7e Duty Cycle 50 % ±5 %
M1-Int:7f FM Deviation Not applicable
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ISO/IEC 18000-4:2008(E)
Table 1 (continued)
Ref. Parameter name Description
M1-Int: 8 Data Coding Manchester
M1-Int: 9 Bit Rate 30 – 40 kbit/s
M1-Int: 9a Bit Rate Accuracy 100 ppm
M1-Int: 10 Interrogator Transmit See 5.2.2.4.1
Modulation Accuracy
M1-Int: 11 Preamble Yes, see 5.2.2.8.3
M1-Int: 11a Preamble length 9 bits, see 5.2.2.8.3
M1-Int: 11b Preamble Waveform See 5.2.2.8.3
M1-Int: 11c Bit Sync Sequence Yes, see 5.2.2.8.4
M1-Int: 11d Frame Sync Sequence Yes, see 5.2.2.8.4
M1-Int: 12 Scrambling (for Spread Not applicable
Spectrum Systems)
M1-Int: 13 Bit transmission order MSB first
M1-Int: 14 Wake-up process Presence of an appropriate RF signal at the tag followed by a wake-up
command as required by the tag type.
M1-Int: 15 Polarisation Interrogator dependent. Not defined in this part of
...