ISO/IEC TR 24769:2008
(Main)Information technology — Real-time locating system (RTLS) device conformance test methods — Test methods for air interface communication at 2,4 GHz
Information technology — Real-time locating system (RTLS) device conformance test methods — Test methods for air interface communication at 2,4 GHz
ISO/IEC TR 24769:2008 defines the test methods for determining the conformance of 2,4 GHz real time locating system (RTLS) tags with the specifications given in the corresponding parts of ISO/IEC 24730-2, but does not apply to the testing of conformity with regulatory or similar requirements. The test methods require only that the mandatory functions, and any optional functions which are implemented, be verified. This may in appropriate circumstances be supplemented by further, application specific, functionality criteria that are not available to the general case. The RTLS tag conformance parameters included in this document include the mandatory direct sequence spread spectrum (DSSS) 2,4 GHz radio frequency beacon. It also includes the optional on-off keyed, frequency shift keyed (OOK/FSK) short range radio frequency link and the optional magnetic air interface. Unless otherwise specified, the tests in ISO/IEC TR 24769:2008 apply exclusively to RTLS tags defined in ISO/IEC 24730-2.
Technologies de l'information — Méthodes d'essai de conformité du dispositif des systèmes de localisation en temps réel (RTLS) — Méthodes d'essai pour la communication d'interface d'air à 2,4 GHz
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Standards Content (Sample)
TECHNICAL ISO/IEC
REPORT TR
24769
First edition
2008-12-15
Information technology — Real-time
locating system (RTLS) device
conformance test methods — Test
methods for air interface communication
at 2,4 GHz
Technologies de l'information — Méthodes d'essai de conformité du
dispositif des systèmes de localisation en temps réel (RTLS) —
Méthodes d'essai pour la communication d'interface d'air à 2,4 GHz
Reference number
ISO/IEC TR 24769:2008(E)
©
ISO/IEC 2008
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ISO/IEC TR 24769:2008(E)
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ISO/IEC TR 24769:2008(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions. 1
3.2 Abbreviated terms . 2
4 Conformance tests for ISO/IEC 24730-2. 2
4.1 General. 2
4.2 Default conditions applicable to the test methods . 2
4.2.1 Test environment. 2
4.2.2 Default tolerance. 3
4.2.3 Noise floor at test location. 3
4.2.4 Total measurement uncertainty . 3
4.3 Tag DSSS RF transmission tests . 3
4.3.1 General. 3
4.3.2 Test Objective . 4
4.3.3 Test procedure . 4
4.3.4 Test measurements and requirements. 4
4.3.5 Test report . 5
4.4 Receiver DSSS RF tests. 5
4.4.1 General. 5
4.4.2 Test objective. 5
4.4.3 Test procedure . 5
4.4.4 Test measurements and requirements. 6
4.4.5 Test report . 7
4.5 Tests for optional air interfaces . 7
4.5.1 Tag optional OOK/FSK RF tests. 7
4.5.2 Tag optional magnetic receiver test . 9
4.5.3 Optional exciter magnetic transmitter test .11
4.5.4 Tag system response timing . 13
Annex A (informative) RF Test measurement site . 15
Annex B (normative) Message formats for tests . 16
Annex C (normative) Technical requirements of measurement antenna and vector signal analyzer . 18
Annex D (normative) Technical requirements of the arbitrary waveform generator and magnetic
coil. 19
Annex E (informative) Configuration file for the Agilent E4438C. 20
Annex F (normative) High SNR demodulation of ISO/IEC 24730-2 DSSS BPSK signals. 31
Annex G (normative) High SNR demodulation of ISO/IEC 24730-2 OOK signals. 32
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ISO/IEC TR 24769:2008(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.
In exceptional circumstances, the joint technical committee may propose the publication of a Technical Report
of one of the following types:
⎯ type 1, when the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts;
⎯ type 2, when the subject is still under technical development or where for any other reason there is the
future but not immediate possibility of an agreement on an International Standard;
⎯ type 3, when the joint technical committee has collected data of a different kind from that which is
normally published as an International Standard (“state of the art”, for example).
Technical Reports of types 1 and 2 are subject to review within three years of publication, to decide whether
they can be transformed into International Standards. Technical Reports of type 3 do not necessarily have to
be reviewed until the data they provide are considered to be no longer valid or useful.
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 TR 24769, which is a Technical Report of type 3, was prepared by Joint Technical Committee
ISO/IEC JTC 1, Information technology, Subcommittee SC 31, Automatic identification and data capture
techniques.
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ISO/IEC TR 24769:2008(E)
Introduction
ISO/IEC 24730 defines the air interfaces and an application programming interface for Real Time Locating
Systems (RTLS) devices used in asset management applications.
This Technical Report contains all measurements required to be made on a product in order to establish
whether it conforms to ISO/IEC 24730-2.
Test methods for measuring performance of equipment compliant with ISO/IEC 24730-2 are given in
ISO/IEC TR 24770.
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TECHNICAL REPORT ISO/IEC TR 24769:2008(E)
Information technology — Real-time locating system (RTLS)
device conformance test methods — Test methods for air
interface communication at 2,4 GHz
1 Scope
This Technical Report defines the test methods for determining the conformance of 2,4 GHz real-time locating
system (RTLS) tags with the specifications given in the corresponding parts of ISO/IEC 24730-2, but does not
apply to the testing of conformity with regulatory or similar requirements.
The test methods require only that the mandatory functions, and any optional functions which are
implemented, be verified. This may in appropriate circumstances, be supplemented by further, application
specific functionality criteria that are not available to the general case.
The RTLS tag conformance parameters included in this document include the mandatory direct sequence
spread spectrum (DSSS) 2,4 GHz radio frequency beacon. It also includes the optional on-off keyed,
frequency shift keyed (OOK/FSK) short range radio frequency link and the optional magnetic air interface
Unless otherwise specified, the tests in this Technical Report apply exclusively to RTLS tags defined in
ISO/IEC 24730-2.
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 19762-1, Information technology — Automatic identification and data capture (AIDC) techniques —
Harmonized vocabulary — Part 1: General terms relating to AIDC
ISO/IEC 19762-3, Information technology — Automatic identification and data capture (AIDC) techniques —
Harmonized vocabulary — Part 3: Radio frequency identification (RFID)
ISO/IEC 24730-2, Information technology — Real-time locating systems (RTLS) — Part 2: 2,4 GHz air
interface protocol
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in ISO/IEC 19762-1, ISO/IEC 19762-3 and
the following apply.
3.1 Terms and definitions
3.1.1
error vector magnitude
EVM
difference between the measured signal and a reference
NOTE A reference is a perfectly modulated signal.
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ISO/IEC TR 24769:2008(E)
3.2 Abbreviated terms
ARB arbitrary waveform generator
BPSK binary phase shift keying
DSSS direct sequence spread spectrum
DUT device under test
EIRP effective isotropic radiated power
EVM error vector magnitude
FSK frequency shift keying
OOK on-off keying
PPM parts per million
RBW resolution bandwidth
RTLS real-time locating system
TIB timed interval blink
VBW video bandwidth
4 Conformance tests for ISO/IEC 24730-2
The following subsections describe the conformance tests.
4.1 General
This Technical Report specifies a series of tests to determine the conformance of RTLS tags to the
ISO/IEC 24730-2 air interfaces. The results of this test shall be compared with the values of the parameters
specified in ISO/IEC 24730-2 to determine whether the tag under test conforms.
This Technical Report also specifies a series of tests to determine the conformance of RTLS RF receivers to
the ISO/IEC 24730-2 air interfaces. The results of these tests shall be compared with the values of the
parameters specified in ISO/IEC 24730-2 to determine whether the RF receiver under test conforms.
This Technical Report additionally specifies tests to determine the conformance of the magnetic exciter device
that is specified as an optional air interface for ISO/IEC 24730-2.
4.2 Default conditions applicable to the test methods
These conditions apply to all tests.
4.2.1 Test environment
Unless otherwise specified, testing shall take place in an environment of temperature 23 °C ± 3 °C
(73° F ± 5° F) and of relative humidity 25 % to 75 %.
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ISO/IEC TR 24769:2008(E)
4.2.2 Default tolerance
Unless otherwise specified, a default tolerance of + 5 % shall be applied to the quantity values given to specify
the characteristics of the test equipment and the test method procedures.
4.2.3 Noise floor at test location
Noise floor at test location shall be measured with the spectrum analyzer in the same conditions as the
measurement of the DUT, with a span of 10 MHz: RBW, VBW and antenna.
The spectrum analyzer shall be configured in acquisition mode for at least 1 minute.
The maximum of the measured amplitude shall be at least 60 dB below the expected value of the amplitude of
the measured tag DSSS transmission at 0 dBm power with the tag placed at 1 meter from the measurement
antenna.
Special attention has to be given to spurious emissions, e.g., insufficiently shielded computer monitors. The
electromagnetic test conditions of the measurements shall be checked by performing the measurements with
and without a tag in the field.
4.2.4 Total measurement uncertainty
The test equipment will introduce a level of measurement uncertainty. For example, the frequency accuracy of
the local oscillator used in RF down-converter will add uncertainty to the calculated frequency accuracy of the
measured RF. The specifications of the test equipment used shall be included in the report.
4.3 Tag DSSS RF transmission tests
This portion of the document describes the tests of the DSSS transmissions.
4.3.1 General
The DUT shall be an RTLS tag. The measurement equipment shall consist of an anechoic chamber as
described in Annex A, and a measuring antenna and a vector signal analyzer for example an Agilent
1)
E4443A with 80 MHz bandwidth, as described in Annex C. Figure 1 shows the required test equipment
setup.
Figure 1 — Setup of equipment for DSSS RF test
1) The Agilent E4443A is an example of a suitable product available commercially. This information is given for the
convenience of users of this Technical Report and does not constitute and endorsement by ISO of this product.
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ISO/IEC TR 24769:2008(E)
4.3.2 Test Objective
The objective of this test is to verify that the RTLS tag provides the appropriate DSSS modulation waveform
required for proper system performance.
4.3.3 Test procedure
The tag shall be configured to transmit a 152-bit DSSS blink (as defined in paragraph 6.3.2.4 of
ISO/IEC 24730-2) at an interval of 10 seconds or less. Each blink shall be configured with at least 2 sub-blinks.
The tag shall be configured to transmit at a class 1 power between 0 dBm and +10 dBm EIRP. The
measurement equipment shall be configured to start capturing for not less than 2.5 milliseconds after the RF
energy detected is above the threshold. The post processing software shall calculate the raw samples and
produce metrics for the following parameters to verify compliance of the tag.
4.3.4 Test measurements and requirements
This section describes the test measurements and requirements.
4.3.4.1 Carrier frequency
The carrier frequency shall be 2 441.750 MHz ± 61 kHz (25 PPM). The carrier frequency drift over the
duration of the entire message shall be less than 5 kHz (2 PPM).
4.3.4.2 Transmit power
The transmitted power shall be calculated based on the power received at the measurement antenna. The
calculated power shall be within ± 2.0 dB of the DUT specified transmit power.
4.3.4.3 Chip rate
The chip rate of the BPSK shall be 30.521 875 MHz ± 763 Hz (25 PPM). No phase transitions shall occur at
less than the chip rate, and all phase transitions shall occur at an integral multiple of the chip rate. An example
methodology for measuring these transitions is provided in Annex F.
4.3.4.4 Message content and structure
The post processing software shall verify the 152-bit message format including preamble, status bits, tag ID,
data, and message CRC are in compliance with the format specified in ISO/IEC 24730-2, sector 6.3.2.1. The
post processing software shall verify differential data encoding within the message.
4.3.4.5 PN code length and polynomial
The polynomial used for driving the BPSK DSSS modulation is defined in Figure 3 of section 6.1 of
ISO/IEC 24730-2. The entire captured message shall be 511 * 152 = 77 672 chips in length. The post
processing software shall verify compliance with the defined PN sequence polynomial and second order non-
linearity equation specified in ISO/IEC 24730-2.
4.3.4.6 Error vector magnitude
A BPSK signal shall produce a phase/amplitude constellation of two points. The post processing software
shall determine the error vector magnitude of the distribution of the captured signal. The EVM must be less
than 10 %.
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ISO/IEC TR 24769:2008(E)
4.3.4.7 Sub-blink interval and dither
Connect the measurement antenna to the vector signal analyzer. Set up the analyzer to trigger on the energy
of the first sub-blink of a blink, and measure the time between the falling edge of the first sub-blink to the rising
edge of the second sub-blink. This interval shall be nominally 125 milliseconds ± 16 milliseconds. Verify that
over several successive blinks, the interval changes but does not go below 108 milliseconds or exceed
142 milliseconds.
4.3.5 Test report
The test report shall contain the tag distance to the measurement antenna and all of the measured data. A
brief narrative of the post processing software used to evaluate the captured signal shall also be included as
an annex to the data. As mentioned before (in 4.2.4), the report shall also contain the uncertainties of the
measurement equipment.
4.4 Receiver DSSS RF tests
This section describes the conformance tests for the base station DSSS receiver (reader).
4.4.1 General
The DUT shall be an RTLS RF receiver. Example measurement equipment could consist of an Agilent
2)
E4438C Vector Signal Generator (VSG) with options 5 (6G hard drive) & 602 (Internal Baseband Generator
64Msa memory). Figure 2 shows the required test equipment set-up. An ISO/IEC 24730-2 format set-up and
configuration file for the Agilent E4438C is also included in this document package in Annex E.
HP E4438C
Vector Signal Generator
DUT
Figure 2 — Setup of equipment for DSSS RF Test
4.4.2 Test objective
The objective of this test is to verify that the RTLS RF receiver (DUT) provides the appropriate DSSS signal
detection required for proper system performance.
4.4.3 Test procedure
The VSG shall be configured to transmit all four blink lengths (56-bit, 72-bit, 88-bit and 152-bit). Each blink
type shall be configured with 8 sub-blinks. This should correspond to an average airtime usage of
2) The Agilent E4438C is an example of a suitable product available commercially. This information is given for the
convenience of users of this Technical Report and does not constitute and endorsement by ISO of this product.
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ISO/IEC TR 24769:2008(E)
approximately 5 % for each of the four types. The post processing software shall calculate the raw samples
and produce detection quality (% of total messages sent) metrics for the test parameters described below to
verify compliance of the RF receiver.
4.4.3.1 152-bit blinks
A 152-bit DSSS blink (as defined in paragraph 6.3.2.4 of ISO/IEC 24730-2) is to be set at an interval of
0,42 seconds. This corresponds to an approximate air time usage of 5% for 8 sub-blink configuration.
4.4.3.2 88-bit blinks
A 88-bit DSSS blink (as defined in paragraph 6.3.2.3 of ISO/IEC 24730-2) is to be set at an interval of
0,24 seconds. This corresponds to an approximate air time usage of 5 % for 8 sub-blink configuration.
4.4.3.3 72-bit blinks
A 72-bit DSSS blink (as defined in paragraph 6.3.2.2 of ISO/IEC 24730-2) is to be set at an interval of
0,20 seconds. This corresponds to an approximate air time usage of 5 % for 8 sub-blink configuration.
4.4.3.4 56-bit blinks
A 56-bit DSSS blink (as defined in paragraph 6.3.2.1 of ISO/IEC 24730-2) is to be set at an interval of
0,15 seconds. This corresponds to an approximate air time usage of 5 % for 8 sub-blink configuration.
4.4.4 Test measurements and requirements
Stated below are the test measurements and requirements.
4.4.4.1 Carrier frequency tests
The centre carrier frequency test shall be 2 441,750 MHz. The edge carrier test frequencies shall be
2 441,811 043 75 MHz (+25 ppm) and 2 441,688 956 25 MHz (−25 ppm). The carrier frequency accuracy for
all three tests should be +/− 1ppm. The carrier frequency drift over the duration of the entire message shall be
less than 4,88 KHz (2 ppm) for all tests.
4.4.4.2 Receiver input RF power levels
The VSG shall be configured to provide two input signal levels to the DUT: −100 dbm (threshold sensitivity) &
−40 dbm (dynamic range).
4.4.4.3 Chip rate
The chip rate of the BPSK shall be 30.521 875 MHz ± 30.5 Hz (1 PPM). No phase transitions shall occur at
less than the chip rate, and all phase transitions shall occur at an integral multiple of the chip rate. An example
methodology for measuring these transitions is provided in Annex F.
4.4.4.4 Message content and structure
The post processing software shall verify the 152-bit message format including preamble, status bits, tag ID,
data, and message CRC are in compliance with the format specified in ISO/IEC 24730-2, sector 6.3.2.1. The
post processing software shall verify differential data encoding within the message for reception error
detection.
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ISO/IEC TR 24769:2008(E)
4.4.4.5 PN code length and polynomial
The polynomial used for driving the BPSK DSSS modulation is defined in Figure 3 of section 6.1 of
ISO/IEC 24730-2. The entire captured message shall be 511 * 152 = 77 672 chips in length. The post
processing software shall verify compliance with the defined PN sequence polynomial and second order non-
linearity equation specified in ISO/IEC 24730-2. As mentioned before (in 4.2.4), the report shall also contain
the uncertainties of the measurement equipment.
4.4.4.6 Detection error magnitude
For each set of the 4 message lengths, 3 test frequencies & 2 RF input levels (24 total tests), the reception
error shall be better than 98 % of all sub-links sent. Each test shall consist of a minimum of 1 000 blinks
X 8 sub-blinks
4.4.4.7 Sub-blink interval and dither
The sub-blink interval shall be nominally 125 milliseconds ± 16 milliseconds. Verify that over several
successive blinks, the interval changes but does not go below 108 milliseconds or exceed 142 milliseconds.
4.4.5 Test report
The test report shall contain a summation detection percentage value for each of the 24 tests and all of the
measured data. A brief narrative of the post processing software used to evaluate the detection percentage
shall also be included as an annex to the data.
4.5 Tests for optional air interfaces
Below are the tests for the air interfaces which are optional.
4.5.1 Tag optional OOK/FSK RF tests
This subsections describes the tests for the OOK/FSK optional air interface.
4.5.1.1 Setup of equipment for optional tag OOK/FSK RF tests
The DUT shall be an RTLS tag. The test shall require an RTLS programmer, or an arbitrary waveform
generator and magnetic transmit coil, to induce the OOK/FSK transmissions. The measurement equipment
shall consist of an anechoic chamber and measuring antenna as described in Annex A, and a measurement
antenna and a vector signal analyzer such as an Agilent E4443A, or equivalent, as described in Annex C.
Figure 3 shows the required test equipment setup.
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ISO/IEC TR 24769:2008(E)
Figure 3 — Setup of equipment for optional OOK/FSK RF test
4.5.1.2 Test objective
The objective of this test is to verify that the RTLS tag provides the appropriate OOK/FSK modulation
waveform required for proper performance with RTLS programmer devices.
4.5.1.3 Test procedure
The tag shall be configured to turn on its receiver at least every 200 milliseconds in order to ensure that it
receives the RTLS programmer’s magnetic message. The RTLS programmer, or arbitrary wave form
generator with magnetic transmit coil shall send the magnetic Who-Are-You message to the tag as defined in
section 7.2.8 of ISO/IEC 24730-2. The measurement equipment shall be configured to start capturing for not
less than 4.5 milliseconds after the detected RF energy of the tag ACK is above the threshold. The post
processing software shall process the raw samples and produce metrics for the following parameters to verify
compliance of the tag.
4.5.1.4 Test measurements
This sections describes the measurements that are to be made in the performing the tests.
4.5.1.4.1 Carrier frequency
The carrier frequency shall be 2 446.519 MHz ± 61 kHz (25 PPM). The carrier frequency drift over the
duration of the entire message shall be less than 5 kHz (2 PPM).
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ISO/IEC TR 24769:2008(E)
4.5.1.4.2 Transmit power
The transmitted power shall be calculated based on the power received at the measurement antenna. The
calculated power shall be 0 dBm ± 2.0 dB.
4.5.1.4.3 Modulation depth and duty cycle
The modulation depth (on-to-off ratio) of the OOK signal shall be greater than 99.36 %, which corresponds to
50 dB.
4.5.1.4.4 FSK frequencies
The logic 0 FSK frequency shall be 376.8 kHz ± 0.1 kHz
The logic 1 FSK frequency shall be 535.5 kHz ± 0.1 kHz.
4.5.1.4.5 OOK/FSK transmission content and format
The post processing software shall verify the content of the 88-bit OOK/FSK message from the tag including
preamble, status, tag ID, ACK, and CRC are in compliance with ISO/IEC 24730-2, section 7.1.3.
4.5.1.4.6 Data rate
The bit data rate of the OOK/FSK signal shall be 19,83 kb/s.
4.5.1.5 Test report
The test report shall contain the tag distance to the measurement antenna and all of the measured data. A
brief narrative of the post processing software used shall also be included as an annex to the test report data.
An description of the functionality of this test software is included in Anne
...
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