ISO/IEC 18000-7:2004

INTERNATIONAL ISO/IEC
STANDARD 18000-7
First edition
2004-08-15
Information technology —
Radio frequency identification for item
management —
Part 7:
Parameters for active air interface
communications at 433 MHz
Technologies de l'information — Identification par radiofréquence
(RFID) pour la gestion d'objets —
Partie 7: Paramètres pour les communications actives d'une interface
d'air à 433 MHz
Reference number
©
ISO/IEC 2004
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©  ISO/IEC 2004
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ii © ISO/IEC 2004 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Conformance. 1
3 Normative references. 1
4 Terms and definitions. 2
5 Symbols and abbreviated terms. 2
6 433,92 MHz active narrowband specification. 2
6.1 Physical layer. 2
6.2 Data Link layer. 2
6.2.1 General. 2
6.2.2 Preamble. 3
6.2.3 Data byte format. 3
6.2.4 CRC bytes. 3
6.2.5 Packet end period . 3
6.2.6 Interrogator to tag message format . 3
6.2.7 Tag to interrogator message format . 5
6.2.8 Tag collection and collision arbitration . 14
6.3 Physical and Media Access Control (MAC) parameters . 16
6.3.1 Interrogator to tag link. 16
6.3.2 Tag to interrogator link. 17
6.3.3 Protocol parameters. 18
6.3.4 Anti-collision parameters. 19
Bibliography . 20

© ISO/IEC 2004 – All rights reserved iii

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 18000-7 was prepared by Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 31, Automatic identification and data capture techniques.
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
iv © ISO/IEC 2004 – All rights reserved

Introduction
This part of ISO/IEC 18000 is intended to address RFID devices operating in the 433 MHz frequency band,
providing an air interface implementation for wireless, non-contact information system equipment for Item
Management applications. Typical applications operate at ranges greater than one meter.
The RFID system includes a host system and RFID equipment (interrogator and tags). The host system runs
an application program, which controls interfaces with the RFID equipment. The RFID equipment is 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 RF communication range. 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. This system uses an
active tag.
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
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 a patent
concerning radio-frequency identification technology given in sub-clause 6.2.
ISO and IEC take no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured the ISO and IEC that they are willing to negotiate licenses under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect,
the statement of the holder of this patent right is registered with ISO and IEC. Information may be obtained
from the following companies.
Affected
Patent Patent subclause in
Contact details Patent title
holder number this part of
ISO/IEC 18000
Ravi Rajapaksi, Savi Communication System for
US 5640151 6.2.6
Chief Technology Officer, Technology Communicating with Tags
Savi Technology, Inc.,
Savi Communication System for
615 Tasman Dr.,
US 5686902 6.2.6
Technology Communicating with Tags
Sunnyvale,
CA 94089
Savi Method and Apparatus for Radio
EP 0467036 6.2.6
USA
Technology Identification and Tracking
Rob Sokohl,
Sterne, Kessler, Goldstein & Fox
P.L.L.C.,
Matrics System and method for electronic
1100 New York Avenue NW, US 6002344 6.2
Technology inventory
Washington,
DC 20005-3934
USA
© ISO/IEC 2004 – All rights reserved v

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 or IEC shall not be held responsible for identifying any or all such
patent rights.
vi © ISO/IEC 2004 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 18000-7:2004(E)

Information technology — Radio frequency identification for
item management —
Part 7:
Parameters for active air interface communications at 433 MHz
1 Scope
This part of ISO/IEC 18000 defines the air interface for radio frequency identification (RFID) devices operating
as an active RF Tag in the 433 MHz band used in item management applications. The purpose of this part of
ISO/IEC 18000 is to provide a common technical specification for RFID devices that may 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 power, 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.
2 Conformance
The rules for RFID device conformity evaluation will be given in a future Technical Report (ISO/IEC TR 18047-7).
3 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 15963, Information technology — Radio frequency identification for item management — Unique
identification for RF tags
ISO/IEC 19762-1, Information technology — Automatic identification and data capture (AIDC) techniques —
1)
Harmonized vocabulary — Part 1: General terms relating to AIDC
ISO/IEC 19762-3, Information technology — Automatic identification and data capture (AIDC) techniques —
1)
Harmonized vocabulary — Part 3: Radio frequency identification (RFID)

1) To be published.
© ISO/IEC 2004 – All rights reserved 1

4 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 19762-1 and ISO/IEC 19762-3
apply.
5 Symbols and abbreviated terms
For the purposes of this document, the symbols and abbreviated terms given in ISO/IEC 19762-1 and
ISO/IEC 19762-3 apply.
6 433,92 MHz active narrowband specification
6.1 Physical layer
The RF communication link between interrogator and tag utilizes narrow band UHF frequency with the
following characteristics:
Carrier Frequency
433,92 MHz ± 20 ppm
Modulation Type FSK
Frequency deviation
± 50 kHz
Symbol LOW fc +50 kHz
Symbol HIGH fc –50 kHz
Modulation rate 27,7 kHz
Wake up Signal 30 kHz
The Wake up signal is transmitted by interrogator for minimum of 2,5 seconds to wake up all tags within
communication range. The wake up signal is a 30 kHz sub-carrier tone for 2,5 to 2,7 seconds. Upon detection
of the Wake up signal all tags will enter into Ready state awaiting command from the interrogator.
The communication between interrogator and tag is of Master-Slave type, where the interrogator always
initiates communications and then listens for response from a tag. Multiple response transmissions from the
tags are controlled by collection algorithm described in section “Tag Collection and Collision Arbitration”.
6.2 Data Link layer
6.2.1 General
Data between interrogator and tag is transmitted in packet format. A packet is comprised of a preamble, data
bytes and a final logic low period. The end of preamble and beginning of the first data byte is indicated by the
last two pulses of the preamble. The same two pulses of the preamble also indicate the originator of the data
packet. Data bytes are sent in Manchester code format. Transmission order is most significant byte first; within
a byte, the order is least significant bit first. Figure 1 illustrates the data communication timing of the preamble
and the first byte of a packet.
2 © ISO/IEC 2004 – All rights reserved

PREAMBLE DATA BYTE
1296 or 1308 us 324 us
b0 b1 b2 b3 b4 b5 b6 b7 b8
0 0 1 0 0 1 1 0 0
1 23 20
30us 30us 42 / 54us 54us 18us
36us
from from
Interrogator
Tag
Pulse width in microseconds. Data byte transmitted significant bit first. Byte shown is code 0x64.

Figure 1 — Data communication timing
6.2.2 Preamble
The preamble is comprised of twenty pulses of 60 µs period, 30 µs high and 30 µs low, followed by a final
sync pulse which identifies the communication direction: 42 µs high 54 µs low (Tag to Interrogator); 54 µs high
54 µs low (Interrogator to Tag).
6.2.3 Data byte format
Data bytes are in Manchester code format, comprised of 8 data bits and one stop bit. The bit period is 36 µs,
the total byte period is 324 µs. A falling edge in the center of the bit-time indicates a 0 bit, a rising edge
indicates a 1 bit. The stop bit is coded as a zero bit.
6.2.4 CRC bytes
A CRC checksum is calculated as a 16-bit value, initialized with all ones (‘FFFF’), over all data bytes
16 12 5
(excluding preamble) according to the CCITT polynomial (x + x + x +1). The CRC is appended to the
data as two bytes. Reference: “The CCITT Red Book”, Volume VIII, International Telecommunications Union,
Geneva, 1986. Recommendation V.41, “Code-Independent Error Control System.”
6.2.5 Packet end period
A final period of 36 µs of continuous logic low is transmitted for each packet after the CRC bytes.
6.2.6 Interrogator to tag message format
Tags shall recognize the following message format:
© ISO/IEC 2004 – All rights reserved 3

Table 1 — Interrogator to tag message format

Optional fields depending Optional field depending
on the Command Type on the Command Type

MSB LSB
Command Command Owner ID Tag ID Interrogator ID Command Parameters CRC
Prefix Type Code
1 byte 1 byte 3 bytes 4 bytes 2 bytes 1 byte N bytes 2 bytes
(‘31’) (8 bits)
The Owner ID, Tag ID and Parameters fields are present as required by the Command Type and Command
code described in the following sections.
6.2.6.1 Command type
Table 2 — Command type field
Bit
7 6 5 4 3 2 1 0
Reserved Reserved Reserved Reserved Reserved 1 0= Broadcast 0= Owner ID not present
(Tag Id not present) 1= Owner ID present
1= Point to Point
(Tag ID present)
The Command Type field is used to indicate the presents of Tag ID and Owner ID fields within the current
data packet. If Interrogator wishes to address a single tag by specifying its Tag ID, Bit 1 of the Command Type
field needs to be set, indicating point-to-point communication. In the case Interrogator wants to address all the
tags within its RF communication range, Bit 1 of the Command Type field needs to be cleared to indicate
broadcast message. A broadcast message does not use Tag ID field and is omitted from the data packet.
The Bit 0 of the Command Type field indicates whether Owner ID is included in Interrogator to Tag message.
If the Owner ID is included in the message all tags within Interrogator’s RF communication range that belongs
to the same Owner ID will respond back. All other tags shall ignore such message.
6.2.6.2 Owner ID
The Owner ID field allows Interrogator to communicate with only those tags that belong to a specific owner ID
group. The Owner ID can be arbitrarily programmed and subsequently changed within each tag’s non-volatile
memory. If the tag is not programmed with Owner ID or its value is set to zero tag shall respond to any
Interrogator command that does not include Owner ID in the command message.
6.2.6.3 Tag ID
The Tag ID is a 32-bit integer number that is uniquely assigned to each individual tag during manufacturing.
This number cannot be changed and is read only. The Tag ID number has no structure and does not contain
any information besides uniquely identifying a tag. The Tag ID cannot be reused. Issuance of the Tag IDs may
be managed and administered by UCC/EAN, ISO 14816, ISO 6346, or some comparable international
organization on behalf of the associated manufacture and is regulated by provision of agreement. ISO/IEC
15963 describes the structure of the Tag ID.
4 © ISO/IEC 2004 – All rights reserved

6.2.6.4 Interrogator ID
The Interrogator ID is 16 bits integer number programmed into the Interrogator non-volatile memory. The
Interrogator ID can be changed without any restrictions and is used to efficiently route tag responses through
Interrogators network. The Interrogators that receive a tag message not addressed to them shall not pass the
message to the system.
6.2.6.5 Command codes
The Command codes and their function as a Read and / or Write command are summarized below. The least
significant 7 bits of a command identify its base function, the eighth (MS) bit is set ‘0’ for a Read function and
‘1’ for a Write function. Codes not identified are reserved.
Table 3 — Command codes
Command Command name Command type Description
code
(R / W)
‘10’ / NA Collection Broadcast Collect all Tag IDs within interrogator RF
communication range
‘11’ / NA Collection with Data Broadcast Collect all Tag IDs including specified data
from tag’s non-volatile memory
’14’ / NA Collection with User ID Broadcast Collect all Tag IDs including tag’s User ID
NA / ’15’ Sleep Point to Point Put Tag to sleep
’01’ / NA Status Point to Point Retrieve Tag status
’07’ / ’87’ User ID length Point to Point Sets length of the User ID (in bytes, 1 – 16)
’13’ / ’93’ User ID Point to Point Sets User assigned ID (1 – 16 bytes)
’09’ / ’89’ Owner ID Point to Point Set Owner ID (3 bytes)
’0C’ / NA Firmware revision Point to Point Set by manufacturer
’0E’ / NA Model Number Point to Point Set by manufacturer
’60’ / ’E0’ Read/Write Memory Point to Point Memory data
NA / ’95’ Set Password Point to Point Sets Tag Password (4 bytes long)
’17’ / ’97’ Set Password Protect Point to Point Sets and Clears Tag Secure bit which
enables or disables password protected
access to the tag
NA/’96’ Unlock Point to Point Unlocks password protected tag

The Command Type column indicates whether the command is broadcast (does not include Tag ID in the
message) or point-to-point (includes Tag ID in the message).
6.2.7 Tag to interrogator message format
The Tag to Interrogator message has two different formats depending on the type of message being
transmitted to the Interrogator.
There are two possible formats:
• Broadcast response message format
• Point-to-Point response message format
© ISO/IEC 2004 – All rights reserved 5

6.2.7.1 Broadcast response message format
This message format is used in response to all Interrogator broadcast commands, received by Interrogator
within its communication range.
The broadcast commands are used to collect Tag Ids, User IDs or short blocks of data from the selected
group of tags (all tags, particular tag type, etc.) using batch collection algorithm. See Collection Command
section for more details.
The User ID field is optional and its use is controlled by
...