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GB/T 20851.5-2007 (GBT20851.5-2007)

GB/T 20851.5-2007_English: PDF (GBT 20851.5-2007, GBT20851.5-2007)
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GB/T 20851.5-2007English110 Add to Cart 0--9 seconds. Auto-delivery [including 2012XG] Electronic toll collection -- Dedicated short range communication -- Part 5: Test methods of the main parameters in physical layer Obsolete GB/T 20851.5-2007

BASIC DATA
Standard ID GB/T 20851.5-2007 (GB/T20851.5-2007)
Description (Translated English) [including 2012XG] Electronic toll collection - Dedicated short range communication - Part 5: Test methods of the main parameters in physical layer
Sector / Industry National Standard (Recommended)
Classification of Chinese Standard L79
Classification of International Standard 35.100.10
Word Count Estimation 11,164
Date of Issue 2007-03-19
Date of Implementation 2007-05-01
Quoted Standard GB 9254-1998; GB/T 12190-2006; GB/T 20851.1-2007
Drafting Organization Research Institute of Highway Ministry
Administrative Organization National Standardization Technical Committee Intelligent Transport Systems
Regulation (derived from) China Announcement of Newly Approved National Standards No. 3 of 2007 (No. 103 overall)
Proposing organization Ministry of Transportation
Issuing agency(ies) Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China; Standardization Administration of China
Summary This standard specifies the electronic toll collection (ETC) Dedicated Short Range Communication (DSRC) the main parameters of the main physical layer test equipment and accessories recommended characteristics, test conditions, test methods. This section applies to highways and city roads electronic toll collection system, automatic vehicle identification, vehicle access control and other fields can refer to use.

Standards related to: GB/T 20851.5-2007

GB/T 20851.5-2007
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 35.100.10
L 79
Electronic toll collection - Dedicated short range
communication- Part 5. Test methods of the
main parameters in physical layer
ISSUED ON. MARCH 19, 2007
IMPLEMENTED ON. MAY 1, 2007
Issued by.
General Administration of Quality Supervision, Inspection
and Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1  Scope ... 4 
2  Normative references ... 4 
3  Symbols and abbreviations ... 4 
4  Main test equipment and recommended characteristics of accessories ... 5 
5  Test conditions ... 7 
6  Test methods ... 8 
Attachment... 14 
Foreword 
GB/T 20851-2007 Electronic toll collection - Dedicated short range communication is
divided into.
— Part 1. Physical payer;
— Part 2. Data link layer;
— Part 3. Application layer;
— Part 4. Equipment application;
— Part 5. Test methods of the main parameters in physical layer.
This is part 5 of GB/T 20851-2007.
This Part was proposed by Ministry of Transport.
This Part shall be under the jurisdiction of National Technical Committee (SAC/TC 268) on
Intelligent Transportation System (ITS) of Standardization Administration of China.
Drafting organization of this Part. Highway Research Institute of Ministry of Transport.
Main drafters of this Part. Wang Xiaojing, Xiao Di, Yang Yun, Chen Bingxun, and Zhong
Chongbo.
Electronic Toll Collection - Dedicated Short Range
Communication - Part 5. Test Methods of the
Main Parameters in Physical Layer
1  Scope 
This Part specifies the main test equipment of main parameters in physical layer of
electronic toll collection (ETC) - dedicated short range communication (DSRC), and
recommended characteristics, test conditions and test methods of accessories.
This Part is applicable to the test of main parameters of the physical layer of electronic toll
collection - dedicated short range communication roadside unit (RSU) and on-board unit
(OBU).
This Part is applicable to highways and city roads’ electronic toll collection system. Fields
such as automatic vehicle identification, vehicle access management may reference to
this Part for the use.
2  Normative references 
The articles contained in the following documents have become articles of this Part of
GB/T 20851 when they are quoted herein. For the dated documents so quoted, all the
modifications (excluding corrections) or revisions made thereafter shall not be applicable
to this Part. For the undated documents so quoted, the latest editions shall be applicable
to this Part.
GB 9254-1998 Information technology equipment - Radio disturbance characteristics -
Limits and methods of measurement (idt CISPR 22. 1997)
GB/T 12190-2006 Method for measuring the shielding effectiveness of electromagnetic
shielding enclosures
GB/T 20851.1-2007 Electronic toll collection - Dedicated short range communication -
Part 1. Physical layer
3  Symbols and abbreviations 
3.1 Symbols
Following symbols apply to this Part.
dBc refers to the ratio of power to carrier signal power
dBm refers to the ratio of power to 1mW, 0 dBm = 1mW
e.i.r.pcon refers to spurious equivalent isotropic radiated power
e.i.r.pmax refers to maximum equivalent isotropic radiated power
fc refers to center frequency of signal source transmitted signal
fTx refers to nominal carrier frequency
fTxa refers to actual carrier frequency
GT refers to test antenna gain
GRx refers to receiving antenna gain of device under test
GTx refers to transmitting antenna gain of device under test
m refers to modulation index
Pcon refers to spurious emission power
Pcw refers to single-frequency signal power of device under test
Pcwo refers to signal source and single-frequency signal power of test antenna
Po refers to signal source output power
∆f refers to carrier frequency error
3.2 Abbreviations
Following abbreviations apply to this Part
DSRC Dedicated Short Range Communication
ETC Electronic Toll Collection
OBU On Board Unit
RBW Resolution Band Width
RSU Roadside Unit
VSWR Voltage Standing-Wave Ratio
4  Main  test  equipment  and  recommended  characteristics  of 
accessories 
4.1 Power meter
— Power measurement range. -60 dBm ~ +20 dBm;
— Frequency range. 10 MHz~18 GHz;
— Power measurement error. ±3%.
4.2 Frequency meter
— Frequency range. 10 Hz~+20 GHz;
— Frequency measurement error. ±10 x 10-9.
4.3 Microwave signal source
— Frequency range. 250 kHz~20 GHz;
— Frequency accuracy. fc x 10 x 10-9;
— Phase noise. Less than -98 dBc/Hz@10 GHz, 1 kHz bias.
4.4 Spectrum analyzer
— Frequency range. 3 Hz~26.5 GHz;
— Dynamic range. Not less than 70 dB;
— Resolution bandwidth. 10 Hz~3 MHz;
— Background noise. Not greater than -140 dBm/Hz.
4.5 Vector signal analyzer
— Frequency range. DC~6 GHz;
— Vector modulation analysis type. Amplitude modulation, frequency modulation and
phase modulation analysis.
4.6 Digital oscilloscope
— Bandwidth. 1 GHz;
— Sampling rate. 2 Gsa/s;
— Memory depth. 2 M points for each channel;
6.4.1 Conduction test
6.4.1.1 Test equipment
Power meter.
6.4.1.2 Test steps
Test steps are as follows.
a) Set the operating frequency of transmitter of device under test; set device under test
in a non-modulation state, i.e. carrier state;
b) Set transmitting frequency of device under test to the maximum value;
c) Use power meter to measure power Pcw of transmitting antenna port of device under
test; calculate corresponding equivalent isotropic radiated power, in dBm;
computational formula.
e.i.r.pmax = Pcw X GTx
Repeat the above steps to measure equivalent isotropic radiated power at other carrier
frequencies.
6.4.2 Radiation test
6.4.2.1 Test equipment
Power meter, microwave signal source.
6.4.2.2 Test steps
Test steps are as follows.
a) Set the operating frequency of transmitter of device under test; test the device under
test in a non-modulation state, i.e. carrier state;
a) Set the transmitting power of device under test to the maximum value;
b) Use power meter to measure the power Pcw;
c) Under the same test conditions, use microwave signal and test antenna of known
gain GT to replace the device under test, and use power meter to measure power
Pcwo; adjust the output power of microwave signal source, until Pcwo is equal to Pcw;
d) Adjust corresponding equivalent isotropic radiated power, in dBm; computational
formula.
e.i.r.pmax = Po X GT
frequency bands, until the power measured by spectrum analyzer is equal to Pcon;
f) Calculate spurious emission e.i.r.pcon at corresponding frequency bands, in dBm;
computational formula.
e.i.r.pcon = Po X GT
Repeat above steps to measure spurious emissions of frequency bands at other carrier
frequencies.
6.6 Modulation mode and modulation index
6.6.1 Test equipment
Vector signal analyzer.
6.6.2 Test steps
This test may be completed at radiation or conduction test conditions. Test steps are as
follows.
a) Set the operating frequency of transmitter of device under test; set the device under
test in a state of continuous emission of test signal;
b) Set transmitting power of device under test to the maximum value;
c) Set modulation index of device under test to the minimum value within its allowable
range;
d) Use vector signal analyzer to measure the modulation index of device under test;
e) Change the operation frequency of transmitter of device under test; measure the
modulation index at other carrier frequencies;
f) Set modulation index of device under test to the maximum value within its allowable
range;
g) Use vector signal analyzer to measure the modulation index of device under test;
h) Change the operating frequency of transmitter of device under test; the remaining
settings are unchanged; test the modulation index under other carrier frequencies.
6.7 Bit rate
6.7.1 Test equipment
Digital oscilloscope.
6.7.2 Test steps
Attachment. 
GB/T 20851.5-2007 “Electronic toll collection - Dedicated short range
communication- Part 5. Test methods of the main parameters in physical
layer” National Standard No. 1 Amendment
The contents in Chapter 1 "This Part is applicable to the test of main parameters of
the physical layer of electronic toll collection dedicated short range communication
road side unit (RSU) and on-board unit (OBU)” is change to be "This Part is applicable
to highways and city roads electronic toll collection system. Fields such as automatic
vehicle identification, vehicle access management may reference to this Part for the
use”.
...