Standard No.:	GB/T 20851.5-2019
Chinese Name:	电子收费 专用短程通信 第5部分:物理层主要参数测试方法
English Name:	Electronic toll collection—Dedicated short range communication—Part 5:Test methods of the main parameters in physical layer
Professional Classification:	L79 Opening and system interconnection of computer
ICS Classification:	35.100.10 Physical layer
Issued by:
Issued on:	2019-05-10
Implemented on:	2019-12-01
Status:	VALID
Replace:	GB/T20851.5-2007 Electronic toll collection—Dedicated short range communication—Part 5:Test methods of the main parameters in physical layer
Language:	English
File Format:	PDF
Word Count:	14000 words
Price(USD):	420 (USD)
Delivery:	via email in 1-3 business day

1 Scope

This part of GB/T 20851 specifies the recommended characteristics, test conditions and test methods of the main test equipment and accessories for the main parameters in physical layer of dedicated short range communication for electronic toll collection.

This part is applicable to electronic toll collection system for highways and urban roads, and may be used as a reference for fields of automated vehicle identification, vehicle access control system, etc.

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.

GB/T 9254 Information technology equipment - Radio disturbance characteristics - Limits and methods of measurement
GB/T 12190-2006 Method for measuring the shielding effectiveness of electromagnetic shielding enclosures
GB/T 20851.1-2019 Electronic toll collection - Dedicated short range communication - Part 1: Physical layer

3 Symbols and abbreviations

3.1 Symbols

For the purposes of this document, the following symbols apply.

D: the maximum diameter of antenna.

d: the distance between equipment under test and test antenna.

dBc: the ratio of representation power to carrier signal power.

dBm: the ratio of representation power to 1mW.

e.i.r.pcon: the spurious equivalent isotropically radiated power.

e.i.r.pmax: the maximum equivalent isotropically radiated power.

f1: the lower limit frequency of receiving bandwidth.

f2: the upper limit frequency of receiving bandwidth.

fc: the center frequency of signal emitted by signal source.

fTx: the nominal carrier frequency.

fTxa: the actual carrier frequency.

GRx: the gain of receiving antenna of equipment under test.

GT: the gain of test antenna.

GTx: the gain of transmitting antenna of equipment under test.

h: the height of equipment under test and test antenna from the ground.