ISO/IEC 18092:2013

INTERNATIONAL ISO/IEC
STANDARD 18092
Second edition
2013-03-15
Information technology —
Telecommunications and information
exchange between systems — Near Field
Communication — Interface and Protocol
(NFCIP-1)
Technologies de l'information — Télécommunications et échange
d'information entre systèmes — Communication de champ proche —
Interface et protocole (NFCIP-1)

Reference number
©
ISO/IEC 2013
©  ISO/IEC 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any
means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission.
Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2013 – All rights reserved

Contents Page
Foreword . v
Introduction . vi
1  Scope . 1
2  Conformance . 1
3  Normative references . 1
4  Terms and definitions . 2
5  Conventions and notations . 4
5.1  Representation of numbers . 4
5.2  Names . 4
6  Abbreviated terms . 4
7  General . 5
8  RF field . 6
8.1  Values . 6
8.2  Passive communication Mode . 6
8.3  Active communication Mode . 6
8.4  External RF field detection . 6
9  RF Signal Interface . 6
9.1  Bit duration . 6
9.2  Active communication mode . 7
9.2.1  Requirements for fc/128 . 7
9.2.2  Requirements for fc/64 and fc/32 . 7
9.3  Passive communication mode . 8
9.3.1  Initiator to Target requirements for fc/128 . 8
9.3.2  Target to Initiator requirements for fc/128 . 9
9.3.3  Initiator to Target requirements for fc/64 and fc/32 . 9
9.3.4  Target to Initiator requirements for fc/64 and fc/32 . 9
10  General Protocol flow . 10
11  Initialisation . 10
11.1  RF Collision Avoidance . 11
11.1.1  Initial RF Collision Avoidance . 11
11.1.2  Response RF Collision Avoidance . 12
11.2  Passive communication mode . 13
11.2.1  Initialisation and Single Device Detection at fc/128 . 13
11.2.2  Initialisation and SDD at fc/64 and fc/32 . 13
11.3  Active communication mode . 17
11.3.1  Initialisation at fc/128, fc/64, and fc/32 . 17
11.3.2  Active communication mode RF Collision Avoidance . 17
12  Transport Protocol . 18
12.1  Transport Data . 18
12.2  Passive communication mode Activation flow . 18
12.3  Active communication mode Activation flow . 19
12.4  Commands . 22
12.5  Activation of the protocol . 22
12.5.1  Attribute Request and Response Commands . 22
12.5.2  Wakeup Request and Response Commands . 28
12.5.3  Parameter Selection Request and Response Commands . 30
© ISO/IEC 2013 – All rights reserved iii

12.6  Data Exchange Protocol .33
12.6.1  Data Exchange Protocol Request and Response .33
12.6.2  Response timeout extension .37
12.6.3  Attention – Target present .37
12.6.4  Protocol operation .37
12.6.5  Multi Activation .37
12.6.6  More information (Chaining) .38
12.7  Deactivation of the protocol .38
12.7.1  Deselect Request and Response command .39
12.7.2  Release Request and Response commands .40
Annex A (normative) CRC calculation .42
A.1  CRC for Active and Passive communication mode at fc/128 .42
A.2  Example of CRC calculation at fc/128 .42
A.3  CRC for Active and Passive communication mode at fc/64 and fc/32 .43
A.4  Example of CRC calculation at fc/64 and fc/32 .43
Annex B (informative) SAK .44

iv © ISO/IEC 2013 – All rights reserved

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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 18092 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
This second edition cancels and replaces the first edition (ISO/IEC 18092:2004), which has been technically
revised.
© ISO/IEC 2013 – All rights reserved v

Introduction
This International Standard specifies the interface and protocol for simple wireless communication between
close coupled devices. These Near Field Communication (NFC) devices communicate with bit rates of 106,
212, and 424 kbit/s.
This NFC Interface and Protocol (NFCIP-1) standard allows, but does not specify, applications in network
products and consumer equipment.
The first edition of ISO/IEC 18092:2004 was prepared by Ecma International (as ECMA-340) and was
adopted, under a special “fast-track procedure”, by Joint Technical Committee ISO/IEC JTC 1, Information
technology, in parallel with its approval by national bodies of ISO and IEC. This second edition of
ISO/IEC 18092 was maintained by JTC 1/SC 6 and Ecma International; it cancels and replaces the first
edition (ISO/IEC 18092:2004), which has been technically revised with fully backward compatibility.

vi © ISO/IEC 2013 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 18092:2013(E)

Information technology — Telecommunications and information
exchange between systems — Near Field Communication —
Interface and Protocol (NFCIP-1)
1 Scope
This International Standard defines communication modes for Near Field Communication Interface and
Protocol (NFCIP-1) using inductive coupled devices operating at the centre frequency of 13,56 MHz for
interconnection of computer peripherals. It also defines both the Active and the Passive communication
modes of Near Field Communication Interface and Protocol (NFCIP-1) to realize a communication network
using Near Field Communication devices for networked products and also for consumer equipment. This
International Standard specifies, in particular, modulation schemes, codings, transfer speeds, and frame
format of the RF interface, as well as initialisation schemes and conditions required for data collision control
during initialisation. Furthermore, this International Standard defines a transport protocol including protocol
activation and data exchange methods.
Information interchange between systems also requires, at a minimum, agreement between the interchange
parties upon the interchange codes and the data structure.
2 Conformance
A system implementing the Active and the Passive communication mode shall be in conformance with this
International Standard if it meets all the mandatory requirements specified herein.
It may also implement the NFC-SEC Option as specified in ISO/IEC 13157-1.
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.
ITU-T V.41:1988, Code-independent error-control system
ISO/IEC 13157-1:2010, Information technology — Telecommunications and information exchange between
systems — NFC Security — Part 1: NFC-SEC NFCIP-1 security services and protocol
ISO/IEC 14443-2:2010, Identification cards — Contactless integrated circuit cards — Proximity cards — Part 2:
Radio frequency power and signal interface
ISO/IEC 14443-3:2011, Identification cards — Contactless integrated circuit cards — Proximity cards — Part 3:
Initialization and anticollision
ISO/IEC 14443-4:2008, Identification cards — Contactless integrated circuit cards — Proximity cards — Part 4:
Transmission protocol
© ISO/IEC 2013 – All rights reserved 1

4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
active communication mode
mode in which both the Initiator and the Target use their own RF field to enable the communication
4.2
ASK modulation
Amplitude Shift Keying, in which the amplitude of the carrier frequency is modulated according to the logic of
the data to be transmitted
4.3
Binary Coded Decimal
BCD
system for representing each of the decimal numbers 0 to 9 by a four-bit binary code
NOTE The bits, from left to right, are worth 8, 4, 2 and 1 respectively in decimal, so for example the number 6 in BCD
is 0110.
4.4
collision
transmission by two or more Targets or Initiators during the same time period, such that the Initiator or the
Target is unable to distinguish from which Target the data originated
4.5
frame
sequence of data bits and optional error detection bits, with frame delimiters at start and end
4.6
H
Threshold
the threshold value to detect an external RF field
4.7
Initiator
generator of the RF field and starter of the NFCIP-1 communication
4.8
load modulation
process of amplitude modulating a radio frequency field by varying the properties of a resonant circuit placed
within the radio frequency field
4.9
lsb first
least significant bit first, indicating a serial data transmission system that sends lsb before all other bits
4.10
LSB first
Least Significant Byte first, indicating a serial data transmission system that sends LSB before all other bytes
4.11
Manchester coding
method of bit coding whereby a logic level during a bit duration is represented by a sequence of two defined
physical states of a communication medium
4.12
modulation index
signal amplitude ratio of [peak – minimum] / [peak + minimum]
2 © ISO/IEC 2013 – All rights reserved

4.13
msb first
most significant bit indicating a serial data transmission system that sends the msb before all other bits
4.14
MSB first
Most Significant Byte indicating a serial data transmission system that sends the MSB before all other bytes
4.15
NFCIP-1 device
entity [ISO/IEC 18092]
4.16
NFC Identifier
NFCIDn
a randomly generated number used by the RF Collision Avoidance and Single Device Detection sequence for
both the Active and the Passive communication modes
4.17
NFC-SEC
NFCIP-1 Security Services and Protocol as specified in ISO/IEC 13157-1
4.18
passive communication mode
when the Initiator is generating the RF field and the Target responds to an Initiator command in a load
modulation scheme
4.19
RF Collision Avoidance
RFCA
method to detect the presence of a RF field based on the carrier frequency and method to detect and resolve
collisions on protocol level
4.20
SAK
Select acknowledge [ISO/IEC 14443-3]
NOTE SAK replaces the SEL_RES [ISO/IEC 18092:2004].
4.21
sensing
NFCIP-1 device in the Active communication mode expecting a Response to a Request it has sent on the RF
field to detect the start of communication to receive the Request
4.22
Single Device Detection
SDD
algorithm used by the Initiator to detect one out of several Targets in its RF field (anti-collision
[ISO/IEC 14443-3])
4.23
Target
responds to Initiator command either using load modulation scheme (RF field generated by Initiator) or using
modulation of self generated RF field
4.24
Time Period
defines the number of slots used for RF Collision Avoidance
© ISO/IEC 2013 – All rights reserved 3

4.25
Time Slot
method of preparing a time window when a Target answers, and assigning and identifying two or more logic
channels
4.26
transaction
initialisation, data exchange and device de-selection
5 Conventions and notations
5.1 Representation of numbers
The following conventions and notations apply in this document unless otherwise stated.
 Letters and digits in single quotation mark represent numbers in hexadecimal notation.
 The setting of bits is denoted by ZERO or ONE.
 Numbers in binary notation and bit patterns are represented by strings of digits 0 and 1 shown with the
most significant bit to the left. Within such strings, X may be used to indicate that the setting of a bit is not
specified within the string. For example (XXXX)b.
5.2 Names
The names of basic elements, e.g. specific fields, are written with a capital initial letter.
6 Abbreviated terms
ALL_REQ Wake up ALL Request
ATR Attribute Request and Attribute Response
ATR_REQ Attribute Request
ATR_RES Attribute Response
BCD Binary Code Decimal
BRi Receiving bit duration supported by Initiator
BRt Receiving bit duration supported by Target
BSi Sending bit duration supported by Initiator
BSt Sending bit duration supported by Target
CMD Command
CRC Cyclic Redundancy Check
D Divisor
DEP Data Exchange Protocol Request and Data Exchange Protocol Response
DEP_REQ Data Exchange Protocol Request
DEP_RES Data Exchange Protocol Response
DIDi Initiator Device ID
DIDt Target Device ID
DRi Data rate Received by Initiator
DRt Data rate Received by Initiator
DSi Data rate Send by Initiator
DSL Deselect Request and Deselect Response
DSL_REQ Deselect Request
DSL_RES Deselect Response
DSt Data rate Send by Target
etu elementary time unit
fc Frequency of operating field (carrier frequency)
fd Baseband frequency of Manchester coding
4 © ISO/IEC 2013 – All rights reserved

fs [ISO/IEC 14443-2] Subcarrier
FRT Frame Response Time
Gi Optional information field for Initiator
Gt Optional information field for Target
HLTA [ISO/IEC 14443-3] HaLT command, Type A
ID Identification number
lsb least significant bit
LSB Least Significant Byte
MI Multiple Information link for Data Exchange Protocol
msb most significant bit
MSB Most Significant Byte
NAD Node Address
NFCID1 fc/128 UID
nfcid1n Byte number n of NFCID1
NFCID2 Random ID for SDD in Passive communication mode at fc/64 and fc/32 bit rates
nfcid2n Byte number n of the Random Identifier NFCID2
NFCID3 Random ID for transport protocol activation
nfcid3n Byte number n of the Random Identifier NFCID3
P Odd parity bit
PA Preamble
PCD Proximity Coupling Device [ISO/IEC 14443-2]
pdu protocol data unit
PFB Control information for transaction
PICC Proximity Card or object [ISO/IEC 14443-2]
PNI Packet Number Information
PPi Protocol Parameters used by Initiator
PPt Protocol Parameters used by Target
PSL Parameter Selection Request and Parameter Selection Response
PSL_REQ Parameter Selection Request
PSL_RES Parameter Selection Response
RF Radio Frequency
RFCA RF Collision Avoidance
RFU Reserved for Future Use
RLS Release Request and Release Response
RLS_REQ Release Request
RLS_RES Release Response
RWT Response Waiting Time
SB Start byte for data exchange protocol at fc/128
SDD Single Device Detection (anti-collision)
SEL_CMD Select Command byte
SYNC Synchronisation pattern
TO Timeout value
UID Unique Identifier [ISO/IEC 14443-3]
WT Waiting Time
WUP Wakeup Request and Wakeup Response
WUP_REQ Wakeup Request
WUP_RES Wakeup Response
7 General
NFCIP-1 Targets and Initiators shall implement both the Active and the Passive communication modes.
In the Active communication mode, both the Initiator and the Target use their own RF field to communicate.
The Initiator starts the NFCIP-1 transaction. The Target responds to an Initiator command in the Active
communication mode by modulating its own RF field.
© ISO/IEC 2013 – All rights reserved 5

In the Passive communication mode, the Initiator generates the RF field and starts the transaction. The Target
responds to an Initiator command in the Passive communication mode by modulating the Initiators’ RF field
which is referred to as load modulation.
This International Standard specifies requirements for modulation, bit rates and bit coding. In addition it
specifies requirements for the start of communication, the end of communication, the bit and byte
representation, the framing and error detection, the single device detection, the protocol and parameter
selection and the data exchange and de-selection of Near Field Communication Interface and Protocol
(NFCIP-1) devices.
Transactions start with device initialisation and end with device de-selection. Initiators and Targets exchange
commands, responses and data in alternating or half duplex communication.
NFCIP-1 devices are capable to start transactions at bit rates of fc/128, fc/64 and fc/32. Initiators select one of
those bit rates to start a transaction and they may change the bit rate using PSL_REQ/PSL_RES commands
during a transaction.
The mode (Active or Passive) shall not be changed during one transaction.
8 RF field
8.1 Values
fc is 13,56 MHz.
H is 1,5 A/m (rms).
min
H is 7,5 A/m (rms).
max
H is 0,1875 A/m (rms).
Threshold
8.2 Passive communication Mode
The Initiator shall generate field strength of at least H and not exceeding H at manufacturer specified
min max
positions (i.e. operating volume) under un-modulated conditions.
The Target shall operate continuously between H and H .
min max
8.3 Active communication Mode
An Initiator and a Target shall alternately generate a RF field of at least H and not exceeding H at
min max
manufacturer specified positions (i.e. operating volume) under un-modulated conditions.
8.4 External RF field detection
NFCIP-1 devices shall detect external RF fields at fc with field strength higher than H .
Threshold
9 RF Signal Interface
9.1 Bit duration
One etu equals 128/(D  fc), where the values of the divisor D depend on the bit rate and communication
mode, see Table 1.
6 © ISO/IEC 2013 – All rights reserved

Table 1 — Divisor D
Communication Mode bit rate Divisor D
active or passive fc/128 (~106 kbit/s) 1
active or passive fc/64 (~212 kbit/s) 2
active or passive fc/32 (~424 kbit/s) 4
Active fc/16 (~848 kbit/s) 8
Active fc/8 (~1695 kbit/s) 16
Active fc/4 (~3390 kbit/s) 32
Active fc/2 (~6780 kbit/s) 64
NOTE 1 The Initiator selects the communication mode (either Active or Passive) and bit rate (fc/128, fc/64 or fc/32
specified by the following clauses).
NOTE 2 This Standard does not specify the modulation and the bit coding beyond the bit rate of fc/32.
9.2 Active communication mode
Targets and Initiators shall comply with the following specifications for both communication directions, i.e.
Initiator to Target and Target to Initiator.
9.2.1 Requirements for fc/128
9.2.1.1 Bit rate
The bit rate for the transmission during initialisation and single device detection shall be fc/128.
9.2.1.2 Modulation
See 8.1.2.1 of ISO/IEC 14443-2. During transmission, both the Initiator and the Target shall conform to PCD
values. During reception, both the Initiator and the Target shall conform to PICC values.
9.2.1.3 Bit representation and coding
See 8.1.3 of the ISO/IEC 14443-2 for a bit rate of fc/128.
9.2.1.4 Byte transmission
Initiators and targets shall transmit bytes with the lsb first.
9.2.2 Requirements for fc/64 and fc/32
9.2.2.1 Bit rates
The bit rates for the transmission during initialisation and single device detection shall respectively be fc/64 or
fc/32.
9.2.2.2 Modulation
See 9.1.2 of ISO/IEC 14443-2 for the bit rate of fc/64 and fc/32. During transmission, both the Initiator and the
Target shall apply the PCD values. During reception, both the Initiator and the Target shall apply the PICC
values.
© ISO/IEC 2013 – All rights reserved 7

NOTE The modulation index range is stricter than that in ISO/IEC 18092:2004.
The Target should accept a modulation index range from 8 % to 30 % to operate with Initiators compliant to
ISO/IEC 18092:2004 using a modulation index higher than 14 %.
9.2.2.3 Bit representation and coding
Manchester bit encoding shall be employed as illustrated in Figure 1 and Figure 2.
Bit coding format is Manchester with logic levels defined as:
 Logic “ZERO”: The first half of the bit duration is carrier low field amplitude, and the second half of the bit
duration shall be carrier high field amplitude (no modulation applied).
 Logic “ONE”: The first half of the bit duration is carrier high field amplitude (no modulation applied), and
the second half of the bit duration shall be carrier low field amplitude.
Reverse polarity in amplitude shall be permitted. Polarity shall be detected from the SYNC.

Figure 1 — Manchester bit encoding (obverse amplitude)

Figure 2 — Manchester bit encoding (reverse amplitude)
9.2.2.4 Byte transmission
Initiators and Targets shall transmit bytes with the msb first.
9.3 Passive communication mode
9.3.1 Initiator to Target requirements for fc/128
See 9.2.1.
8 © ISO/IEC 2013 – All rights reserved

9.3.2 Target to Initiator requirements for fc/128
9.3.2.1 Bit rate
See 9.2.1.1.
9.3.2.2 Modulation
See 8.2.2 of ISO/IEC 14443-2.
9.3.2.3 Subcarrier Frequency
See 8.2.3 of ISO/IEC 14443-2.
9.3.2.4 Subcarrier modulation
See 8.2.4 of ISO/IEC 14443-2 for a bit rate of fc/128.
9.3.2.5 Bit representation and coding
See 8.2.5.1 of ISO/IEC 14443-2.
9.3.2.6 Byte transmission
Initiators and Targets shall transmit bytes with the lsb first.
9.3.3 Initiator to Target requirements for fc/64 and fc/32
9.3.3.1 Bit rate
See 9.2.2.1.
9.3.3.2 Modulation
See 9.1.2 of ISO/IEC 14443-2 for the bit rate of fc/64 and fc/32. During transmission, the Initiator shall apply
the PCD values.
NOTE The modulation index range is stricter than that in ISO/IEC 18092:2004.
9.3.3.3 Bit representation and coding
See 9.2.2.3.
9.3.3.4 Byte transmission
See 9.2.2.4.
9.3.4 Target to Initiator requirements for fc/64 and fc/32
9.3.4.1 Bit rate
See 9.2.2.1.
© ISO/IEC 2013 – All rights reserved 9

9.3.4.2 Modulation
The Target shall be capable of communication to the Initiator via an inductive coupling area by using load
modulation applied at fc of the Initiator’s RF field with the PICC load modulation amplitude value specified in
8.2.2 of ISO/IEC 14443-2.The Initiator shall be able to receive a signal with load modulation amplitude as
specified for the PCD reception in ISO/IEC 14443-2, 8.2.2.
NOTE The minimum load modulation amplitude value for the Target and Initiator has been modified from ISO/IEC
18092:2004.
9.3.4.3 Bit representation and coding
See 9.2.2.3.
9.3.4.4 Byte transmission
See 9.2.2.4.
10 General Protocol flow
The General Protocol flow between NFCIP-1 devices shall be conducted through the following consecutive
operations:
 Any NFCIP-1 device shall be in Target mode initially and not generate an RF field, and shall wait for a
command from an Initiator.
 The NFCIP-1 device may switch to Initiator mode and select either Active or Passive communication
mode and transfer speed.
 Initiators shall test for external RF field presence and shall not activate their RF field if an external RF field
is detected. See 8.4.
 If an external RF field is not detected, the Initiator shall activate its own RF field for the activation of
Target.
 Exchange commands and responses in the same communication mode and the transfer speed.
Figure 3 shows the general initialisation and single device detection flow for the Active and the Passive
communication mode at different transfer speeds.
The General Protocol flow describes the flow to initialise and select the Targets either in the Passive
communication mode or in the Active communication mode using one of the chosen transfer speeds. RF
Collision Avoidance is described in 11.1. Passive communication mode is described in 11.2. The initialisation
and SDD for the bit rate of fc/128 is described in 11.2.1, initialisation and SDD for bit rates of fc/64 and fc/32 is
described in 11.2.2. The Active communication mode is described in 11.3.
The Activation of the Protocol is described in 12.5. The Parameter Selection is described in 12.5.3. The Data
Exchange Protocol is described in 12.6. The Deactivation is described in 12.7.
11 Initialisation
This section describes the initialisation and collision detection protocol for Targets in the Active and the
Passive communication mode. The Initiator shall detect a collision that occurs, when at least two Targets
simultaneously transmit bit patterns with one or more bit positions where they transmit complementary values.
10 © ISO/IEC 2013 – All rights reserved

Figure 3 shows the general initialisation and Single Device Detection flow for the Active and the Passive
communication mode at different transfer speeds.
Start
Initial RF Collision
Avoidance
RF field detected ?
Yes
No
Application switches to
Application switches to
initiator mode for Passive
initiator mode for Active
communication mode and
communication mode
chooses the tranfer speed
and chooses transfer
and performs the initialisation
speed
and the SDD
Activation in Passive Activation in Active
communication mode communication mode
Protocol
by NFCID3 (ATR) by NFCID3 (ATR)
Activation
Parameter selection Parameter
(PSL)
Selection
Data
Data exchange protocol Exchange
(DEP) Protocol
De-Activation
De-
(DSL,RLS)
Activation
End transaction
Figure 3 — General initialisation and single device detection flow
11.1 RF Collision Avoidance
In order not to disturb any other NFC communication and any current infrastructure running on the carrier
frequency, an Initiator for NFC communication shall not generate its own RF field as long as another RF field
is detected.
11.1.1 Initial RF Collision Avoidance
To start communication with the Target device either in the Active or the Passive communication mode an
Initiator shall sense continuously for the presence of an external RF field. See 8.4.
© ISO/IEC 2013 – All rights reserved 11

Transport Protocl Initialisation

If the Initiator detects no RF field within the timeframe T + n  T then the Initiator shall switch its RF field
IDT RFW
on, else it shall restart Initial RF Collision Avoidance. The integer value of n shall be randomly generated.
Figure 4 specifies the timing of the initial RF Collision Avoidance during initialisation.
Send Request
RF On
TRFW
Start
TIRFG
TIDT
n x TRFW
.
Figure 4 — Initial RF Collision Avoidance
T : Initial delay time. T > 4 096 / fc
IDT IDT
T : RF waiting time. 512 / fc
RFW
n: randomly generated number of Time Periods for T .
RFW
0  n  3
T : Initial guard-time between switching on RF field and start to send command or data frame.
IRFG
T > 5 ms
IRFG
The RF field, which is generated by the Initiator, shall be switched off in the Active communication mode. The
RF field, which is generated by the Initiator, shall not be switched off in the Passive communication mode.
11.1.2 Response RF Collision Avoidance
To avoid collision by simultaneous responding of more than one Target in the Active communication mode
during activation, Targets shall perform response RF collision avoidance as specified in Figure 5.
Send Response
RF On
TRFW
Start
TADT TARFG
n x TRFW
.
Figure 5 — Response RF Collision Avoidance sequence during activation
12 © ISO/IEC 2013 – All rights reserved

T : Active delay time, sense time between RF off Initiator/Target and Target/Initiator.
ADT
(768/fc  T  2 559/fc)
ADT
T : RF waiting time. (512/fc)
RFW
n: Randomly generated number of Time Periods for T . (0  n  3)
RFW
T : Active guard time between switching on RF field and start to send command. (T > 1024/fc)
ARFG ARFG
11.2 Passive communication mode
11.2.1 Initialisation and Single Device Detection at fc/128
See ISO/IEC 14443-3, Clause 6 with the coding of SAK as specified in Table 2.
Table 2 — coding of SAK
bit 8 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 Meaning
x x x x x 1 x x UID not complete, see Table 9 of ISO/IEC 14443-3.
x x 1 x x 0 x x UID complete, see Table 9 of ISO/IEC 14443-3.
x x 0 x x 0 x x UID complete, see Table 9 of ISO/IEC 14443-3.
UID complete, Target compliant with NFCIP-1
x 1 x x x 0 x x
transport protocol. Request for Attributes supported.
UID complete, Target does not supportNFCIP-1
x 0 x x x 0 x x transport protocol, Request for Attributes not
supported.
The uid0 shall be set to '08'.
If bit 3 is (1)b the Initiator shall ignore any other bit of SAK. If bit 3 is (0)b the Initiator shall interpret bit 7 and
ignore the other bits. When bit 3 is set to (1)b then the Target should set all other bits of SAK to (0)b.
NOTE 1 UID replaces NFCID1 of ISO/IEC 18092:2004 and uid* replaces nfcid1 of ISO/IEC 18092:2004.
NOTE 2 If bit 6 is (1)b in SAK then device supports protocol as defined in ISO/IEC 14443-4.
11.2.2 Initialisation and SDD at fc/64 and fc/32
11.2.2.1 Start and end of communication
The start of the Passive communication shall be signalled by the presence of the carrier frequency. The
communication shall start with the preamble sequence of at least 48 bits of Manchester encoded ZERO. The
end of communication shall be forecasted from the Length field of the frame. Figure 6 illustrates the start and
end of communication.
© ISO/IEC 2013 – All rights reserved 13

No modulation
No modulation Preamble Data packet

Figure 6 — Start and end of communication
After one NFCIP-1 device has finished communication, the other shall delay for a period of at least 8  64/fc
before starting transmission by sending the preamble sequence as shown in Figure 7.
Data packet Delay Data packet
Preamble
Figure 7 — Delay between consecutive frames
11.2.2.2 Frame format
The frame format of shall consist of Preamble, SYNC, Length, Payload, and CRC, see Figure 8.
The Preamble shall be 48 bits minimum all logical ZEROs.
The SYNC shall be 2 bytes. The 1st byte of the SYNC shall be ‘B2’ and the 2nd byte shall be ‘4D’.
Preamble SYNC Length Payload CRC
Figure 8 — Frame format
The Length shall be an 8-bit field and it shall be set to the number of bytes to be transmitted in Payload plus 1.
The range of the Length shall be 2 to 255, and other settings are RFU.
The Payload shall consist n 8-bit-bytes of data where n is indicated by the number of data bytes.
The CRC shall be calculated according to A.3.
11.2.2.3 Single Device Detection at fc/64 and fc/32
The basic technique of the SDD procedure shall be the Time Slot method. The number of the Slot shall be the
integer value beyond zero. The Initiator shall send Polling Requests. The Target shall respond at random in
each Time Slot. The Initiator shall be able to read NFCID2 data (see 11.2.2.4) of Target(s) in different Time
Slots.
After obtaining NFCID2 data from Target(s) in the operating field, the Initiator may communicate with multiple
Targets.
14 © ISO/IEC 2013 – All rights reserved

Up to 16 Time Slots may be supported by agreement between the interchange parties. The number of Time
Slot may be indicated by the value TSN in the Polling Request Frame from the Initiator.
A Target, which is already powered up, responds to the Initiator according to the following rules after receiving
the Polling Request Frame from the Initiator.
1. The Target shall generate a random number R in the range 0 to TSN.
2. The Target shall wait until the Time Slot is matched to R, then send the Polling Response Frame and
wait for the next Request. The Target may ignore a Polling Request to reduce instances of collision of
Responses.
The communication between the Initiator and the Target shall be initiated as follows:
1. The Target gets power from the operating field generated by the Initiator.
2. The Target shall become ready for receiving a Polling Request from the Initiator in maximum 2 seconds
from power up.
3. The Target shall wait for a Polling Request sent from the Initiator. The Initiator may send a Polling
Request without waiting for the Target to become ready.
4. If the Initiator fails to receive Polling Response, then the Initiator may send Polling Request again. The
Initiator of the Passive communication mode shall keep RF power on while executing the SDD
procedure.
The delay Td between the end of the Request Frame and the first Time Slot shall be 512  64/fc.
The Time Slot unit Ts shall be 256  64/fc.
Figure 9 illustrates an example situation of the SDD by Time Slot. In this example, 5 Targets are responding.
The Initiator may be able to get the Response information of the Target 2, 4, and 5 excluding 1 and 3.
Because a collision has occurred at the Time Slot 1.
The Initiator may repeat SDD procedure.

 Td   Ts   Ts   Ts   Ts 
Time  Time Slot 0  Time Slot 1  Time Slot 2  Time Slot 3

REQ from  RES from  RES from  RES from  RES from
Initiator Target 4 Target 1 Target 5 Target 2

RES from
Target 3
Figure 9 — Single Device Detection by Time Slot
11.2.2.4 NFCID2 contents
NFCID2 shall be an 8-byte number for identifying NFCIP-1 devices. The 2-byte prefix code shall be followed
by a 6-byte number in the NFCID2. The prefix code shall define the characteristics for the 6-byte number.
The 6-byte number shall be randomly generated while the prefix code is ‘01’ ‘FE’. Other settings for the prefix
code are RFU.
© ISO/IEC 2013 – All rights reserved 15

11.2.2.5 Polling Request Frame format
To find Targets, an Initiator shall send a Polling Request frame, see Figure 10.
Preamble SYNC Length Payload CRC
(48 bit min.) (16 bit) (8 bit) (16 bit)
‘00’ ‘FF’ ‘FF’ ‘00’ TSN
Figure 10 — Polling Request Frame format
The Preamble shall be 48 bits minimum all logical ZEROs.
The synchronisation (SYNC) pattern shall be 2 byte. The 1st byte of the synchronisation pattern shall be ‘B2’
and the 2nd byte shall be ‘4D’.
The Length shall be set to ‘06’.
The 1st byte of the Payload shall be set to ‘00’.
The 2nd byte and the 3rd of Payload shall be set to ‘FF’ and other settings are RFU.
The 4th byte of Payload shall be set to ‘00’, and other settings are RFU.
The TSN shall be ‘00’, ‘01’, ‘03’, ‘07’, or ‘0F’. Any other settings are RFU.
The CRC shall be calculated according to A.3.
Figure 9 illustrates an example where the TSN is ‘03’. If the TSN is set to ‘00’ then only the Time Slot 0 shall
be used.
11.2.2.6 Polling Response Frame format
Target shall send the following frame as the Polling Response toward the Polling Request, see Figure 11.
Preamble SYNC Length Payload CRC
(48 bit min.) (16 bit) (8 bit) (16 bit)
‘01’ NFCID2 Pad
Figure 11 — Polling Response Frame format
The Preamble shall be 48 bits minimum all logical “ZERO”.
The synchronisation (SYNC) pattern shall be 2 byte. The 1st byte of the synchronisation pattern shall be ‘B2’
and the 2nd byte shall be ‘4D’.
The Length field shall be set ‘12’.
The start byte of the Payload shall be set to ‘01’. The Payload shall contain 8-byte of NFCID2 and 8-byte of
Pad. The Pad shall be ignored for data interchange.
The CRC shall be calculated according to A.3.
16 © ISO/IEC 2013 – All rights reserved

11.3 Active communication mode
11.3.1 Initialisation at fc/128, fc/64, and fc/32
The application switches to Initiator for the Active communication mode and may choose fc/128, fc/64 or fc/32.
11.3.2 Active communication mode RF Collision Avoidance
The RF Collision Avoidance shall be executed according to the timing chart in Figure 12.
 The Initiator shall perform the initial RF Collision Avoidance.
 The first command sends by the Initiator is the ATR_REQ in the Active communication mode at a
selected transfer speed.
 The Initiator shall switch off the RF field.
 The Target performs the response RF Collision Avoidance.
 The Target sends the ATR_RES as a response to the ATR_REQ in the same transfer speed as it has
received the ATR_REQ and switch of the RF field.
 The Initiator performs
...