标准编号:	GB/T 20851.1-2019
中文名称:	电子收费 专用短程通信 第1部分：物理层
英文名称:	Electronic toll collection—Dedicated short range communication—Part 1:Physical layer
中标分类:	L79    计算机开放与系统互连
行业分类:	GB    国家标准
ICS分类:	35.100.10 35.100.10    物理层 35.100.10
发布机构:	国家市场监督管理总局 国家标准化管理委员会
发布日期:	2019-05-10
实施日期:	2019-12-1
标准状态:	valid
替代旧标准:	GB/T 20851.1-2007 电子收费 专用短程通信 第1部分：物理层 GB/T 20851.1-2007/XG1-2012 《电子收费 专用短程通信 第1部分：物理层》含国家标准第1号修改单
翻译语言:	英文
文件格式:	PDF

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. GB/T 20851 comprises the following parts under the general title Electronic toll collection - dedicated short range communication: —— Part 1: Physical layer; —— 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 1 of GB/T 20851. This part is developed in accordance with the rules given in GB/T 1.1-2009. This part replaces GB/T 20851.1-2007 Electronic toll collection - Dedicated short range communication - Part 1: Physical layer. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 20851.1-2007: —— the technical requirements are modified for downlink, the contents of "downlink" are moved into the "technical requirements for downlink" (see clause 6 of this standard; 5.2 of Edition 2007); —— the requirements are added for downlink antenna side lobe level, antenna front-to-back ratio, 14 kHz square wave wake-up signal accuracy, OBU maximum input signal power, OBU cochannel interference rejection ratio, OBU adjacent channel interference rejection ratio, OBU blocking interference rejection ratio and other indicators (see clause 6 of this standard); —— the requirements are modified for downlink modulation factor, OBU reception bandwidth, preamble and other indicators (see clause 6 of this standard; 5.2 of Edition 2007); —— the technical requirements are modified for uplink, the contents of "uplink" are moved into the "technical requirements for uplink" (see clause 7 of this standard; 5.3 of Edition 2007); —— the requirements are added for the uplink RSU maximum input signal power, RSU cochannel interference rejection ratio, RSU adjacent channel interference rejection ratio, RSU blocking interference rejection ratio, RSU reception bandwidth and other indicators (see clause 7 of this standard); —— the requirements are modified for the uplink adjacent channel leakage power ratio, modulation factor, bit clock accuracy, preamble and other indicators (see clause 7 of this standard; 5.3 of Edition 2007); This part was proposed by and is under the jurisdiction of the National Technical Committee 268 on Intelligent Transportation Systems of Standardization Administration of China. The previous edition replaced by this part is as follows: —— GB/T 20851.1-2007. Electronic toll collection - Dedicated short range communication - Part 1: Physical layer 1 Scope This part of GB/T 20851 specifies the basic requirements of the physical layers used for dedicated short range communication of electronic toll collection and technical requirements for the downlink and uplink. 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 9410-2008 General specification for antennas used in the mobile communications GB/T 13622-2012 Terminology for radio regulation GB/T 14733.7-2008 Terminology for telecommunication - Oscillations, signals and related devices GB/T 14733.9-2008 Terminology for telecommunication - Radio wave propagation GB/T 20839-2007 Intelligent transport systems - General terminology 3 Terms and definitions For the purposes of this document, the terms and definitions given in GB/T 9410-2008, GB/T 13622-2012, GB/T 14733.7-2008, GB/T 14733.9-2008, and GB/T 20839-2007 and the following apply. 3.1 wakeup the process by which an on-board unit (OBU) transits from a dormant state to an operating state 3.2 preamble the presignal of the physical layer frame information which is independent from the link layer and may be a modulated or unmodulated carrier 3.3 post-amble The postsignal of the physical layer frame information which is independent from the link layer and may be a modulated or unmodulated carrier 4 Symbols and abbreviations 4.1 Symbols For the purposes of this document, the following symbols apply. dBm: the ratio of power to 1 mW. RSU1: transmitting antenna of roadside unit. RSUr: receiving antenna of roadside unit. 4.2 Abbreviations For the purposes of this document, the following abbreviations apply. ASK: Amplitude Shift Keying BER: Bit Error Rate e.i.r.p: Equivalent Isotropically Radiated Power ETC: Electronic Toll Collection FSK: Frequency Shift Keying OBU: On Board Unit RSU: Roadside Unit XPD: Cross Polarization Discrimination 5 General requirements The physical layer includes uplink and downlink, and each link shall meet the corresponding technical requirements. Physical layer links involve two categories of requirements: Categories A and B. Category A shall be applicable to ETC applications. Category B may also support high rate data transfer applications on the basis of being applicable to ETC applications. The requirements for carrier frequency, e.i.r.p and spurious emission shall conform to the regulations of relevant competent departments. Refer to the Notice on the use of 5.8 GHz frequency band for regulations on frequency band management. 6 Technical requirements for downlink The technical requirements for downlink are shown in Table 1. Table 1 Technical requirements for downlink S.N. Parameters Category A Category B 1 Carrier frequency Channel 1 5.830 GHz 5.830 GHz Channel 2 5.840 GHz 5.840 GHz 2 Occupied bandwidth ≤5 MHz ≤5 MHz 3 Frequency tolerance ±10×10-6 ±5×10-6 4 e.i.r.p ≤ + 33 dBm ≤ + 33 dBm 5 Spurious emission 30 MHz ~ 1,000 MHz ≤ -36 dBm/100 kHz ≤ -36 dBm/100 kHz 2,400.0 MHz ~ 2,483.5 MHZ ≤ -40 dBm/1 MHz ≤ -40 dBm/1 MHz 3,400 MHz ~ 3,530 MHZ ≤ -40 dBm/1 MHz ≤ -40 dBm/1 MHz 5,725 MHz ~ 5,850 MHZa ≤ -33 dBm/100 kHz ≤ -33 dBm/100 kHz Others 1 GHz ~ 20 GHz ≤ -30 dBm/1 MHz ≤ -30 dBm/1 MHz 6 Adjacent channel leakage power ratio ≤ -30 dB ≤ -30 dB 7 Half power lobe width of antenna Horizontal plane < 38° < 38° Vertical plane < 45° < 45° 8 Antenna side lobe level < -20 dB < -20 dB 9 Antenna front-to-back ratio > +25 dB > +25 dB 10 Antenna polarization Right-handed circular polarization Right-handed circular polarization 11 XPD Maximum gain direction RSUt ≥ 15 dB RSUt ≥ 15 dB -3 dB area RSUt ≥ 10 dB RSUt ≥ 10 dB 12 Modulation mode ASK FSK 13 Modulation factor/ modulation error Modulation factor: 0.7~0.9 Modulation error: -200 kHz~+200 kHz 14 Frequency offset — ± 512 kHz 15 Encoding mode FM0 MANCHESTER 16 Bit rate 256 kbit/s 1 Mbit/s 17 Bit clock accuracy ± 100×10-6 ± 20×10-6 18 OBU wakeup methodb 15 ~ 17 periods of 14 kHz square wave 15 ~ 17 periods of 14 kHz square wave 19 14 kHz square wave wakeup signal accuracy ± 0.5 kHz ± 0.5 kHz 20 OBU wakeup time < 5 ms < 5 ms 21 OBU wakeup sensitivity ≤ -40 dBm ≤ -40 dBm 22 OBU receiving sensitivity ≤ -50 dBmc ≤ -70 dBm 23 OBU maximum input signal power ≥ -20 dBm ≥ -20 dBm 24 OBU cochannel interference rejection ratio < + 15 dB < + 15 dB 25 OBU adjacent channel interference rejection ratio < + 15 dB < + 15 dB 26 OBU blocking interference rejection ratio < - 10 dB < - 10 dB 27 OBU reception bandwidth Maximum: 5.825 GHz~5.845 GHz, minimum: 5.8285 GHz~5.8315 GHz, 5.8385 GHz~5.8415 GHz Maximum: 5.825 GHz~5.845 GHz, minimum: 5.8285 GHz~5.8315 GHz, 5.8385 GHz~5.8415 GHz 28 BER Within 10 × 10-6 Within 1 × 10-6 29 Preambled 16-bit "1" plus 16-bit "0" 16-bit "1" plus 16-bit "0" 30 Post-amble 1~8 bits 1~8 bits a It corresponds to emission on a frequency, or frequencies, which are outside the 2.5 times the carrier channel bandwidth. b The RSU is required to transmit this waveform; the OBU may choose to be wakeup by this waveform or by normal communication frame signals. c The OBU receiving sensitivity shall be greater than the wakeup sensitivity by over 5 dB. d The time interval between the end of the 14 kHz square wave wakeup signal and the start of the preamble shall not be greater than 72 μs. 7 Technical requirements for uplink

Foreword III 1 Scope 2 Normative references 3 Terms and definitions 4 Symbols and abbreviations 5 General requirements 6 Technical requirements for downlink 7 Technical requirements for uplink Bibliography

ICS 35.100.10 L 79 中华人民共和国国家标准 GB/T 2085 1.1—2019 代替GB/T 20851.1—2007 电子收费 专用短程通信 第1部分：物理层 Electronic toll collection—Dedicated short range communication— Part 1：Physical layer 2019-05-10发布 2019-12-01实施 国家市场监督管理总局 中国国家标准化管理委员会 发布 前言 GB/T 20851《电子收费 专用短程通信》分为5个部分： ——第1部分：物理层； ——第2部分：数据链路层； ——第3部分：应用层； ——第4部分：设备应用； ——第5部分：物理层主要参数测试方法。 本部分为GB/T 20851的第1部分。 本部分按照GB/T 1.1—2009给出的规则起草。 本部分代替GB/T 20851.1—2007《电子收费 专用短程通信 第1部分：物理层》，与GB/T 20851.1—2007相比，除编辑性修改外主要技术变化如下： ——修改了下行链路技术要求，将“下行链路”内容移入“下行链路技术要求”(见第6章，2007年版的5.2)； ——增加了下行链路天线旁瓣电平、天线前后比、14 kHz方波唤醒信号精度、OBU最高输入信号功率、OBU同信道干扰抑制比、OBU邻信道干扰抑制比、OBU阻塞干扰抑制比等指标的规定(见第6章)； ——修改了下行链路调制系数、OBU接收带宽、前导码等指标的规定(见第6章，2007年版的5.2)； ——修改了上行链路技术要求，将“上行链路”内容移入“上行链路技术要求”(见第7章，2007年版的5.3)； ——增加了上行链路RSU最高输入信号功率、RSU同信道干扰抑制比、RSU邻信道干扰抑制比、RSU阻塞干扰抑制比、RSU接收带宽等指标的规定(见第7章)； ——修改了上行链路邻道泄漏功率比、调制系数、位时钟精度、前导码等指标的规定(见第7章，2007年版的5.3)。 本部分由全国智能运输系统标准化技术委员会(SAC/TC 268)提出并归口。 本部分所代替标准的历次版本发布情况为： ——GB/T 20851.1—2007。 电子收费 专用短程通信 第1部分：物理层 1 范围 GB/T 20851的本部分规定了用于电子收费专用短程通信物理层的基本要求，以及下行链路和上行链路技术要求。 本部分适用于公路和城市道路电子收费系统，自动车辆识别、车辆出入管理等领域可参照使用。 2规范性引用文件 下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。 GB/T 9410—2008 移动通信天线通用技术规范 GB/T 13622—2012 无线电管理术语 GB/T 14733.7—2008 电信术语 振荡、信号和相关器件 GB/T 14733.9—2008 电信术语 无线电波传播 GB/T 20839—2007 智能运输系统 通用术语 3术语和定义 GB/T 9410—2008、GB/T 13622—2012、GB/T 14733.7—2008、GB/T 14733.9—2008和GB/T 20839—2007中界定的以及下列术语和定义适用于本文件。 3.1 唤醒wakeup 车载单元(OBU)由休眠状态转换为工作状态的过程。 3.2 前导码preamble 物理层帧信息的前置信号，与链路层无关，可以是调制或者未调制的载波。 3.3 后导码post-amble 物理层帧信息的后置信号，与链路层无关，可以是调制或者未调制的载波。 4符号和缩略语 4.1 符号 下列符号适用于本文件。 dBm：表征功率与1 mW的比值。 RSU1：路侧单元发射天线。 RSUr：路侧单元接收天线。 4.2 缩略语 下列缩略语适用于本文件。 ASK：幅移键控(Amplitude Shift Keying) BER：位误码率(Bit Error Rate) e.i.r.p：等效全向辐射功率(equivalent isotropically radiated power) ETC：电子收费(Electronic Toll Collection) FSK：频移键控(Frequency Shift Keying) OBU：车载单元(On Board Unit) RSU：路侧单元(Roadside Unit) XPD：交叉极化鉴别率(Cross Polarization Discrimination) 5 基本要求 物理层包括上行链路和下行链路，各链路应分别符合相应的技术要求。 物理层链路包括A和B两类要求，A类应满足ETC应用，B类在满足ETC应用的基础上，还可支持较高速率数据传输应用。 载波频率、e.i.r.p和杂散发射的要求应符合有关主管部门规定。有关频段频率管理规定参见《关于使用5.8 GHz频段频率事宜的通知》。 6 下行链路技术要求 下行链路技术要求见表1。 表1 下行链路技术要求 序号 参数 A类 B类 1 载波频率 信道1 5.830 GHz 5.830 GHz 信道2 5.840 GHz 5.840 GHz 2 占用带宽 ≤5 MHz ≤5 MHz 3 频率容限 ±10×10-6 ±5×10-6 4 e.i.r.p ≤+33 dBm ≤+33 dBm 5 杂散发射 30 MHz～1 000 MHz ≤-36 dBm/100 kHz ≤-36 dBm/100 kHz 2 400.0 MHz～2 483.5 MHZ ≤-40 dBm/1 MHz ≤-40 dBm/1 MHz 3 400 MHz～3 530 MHZ ≤-40 dBm/1 MHz ≤-40 dBm/1 MHz 5 725 MHz～5 850 MHZ8 ≤-33 dBm/100 kHz ≤-33 dBm/100 kHz 其他1 GHz～20 GHz ≤-30 dBm/1 MHz ≤-30 dBm/1 MHz 6 邻道泄漏功率比 ≤-30 dB ≤-30 dB 7 天线半功率波瓣宽度 水平面 <38° <38° 垂直面 <45° <45° 8 天线旁瓣电平 <-20 dB <-20 dB 9 天线前后比 >+25 dB >+25 dB 10 天线极化 右旋圆极化 右旋圆极化 11 XPD 最大增益方向 RSUt≥15 dB RSUt≥15 dB -3 dB区域 RSUt≥10 dB RSUt≥10 dB 12 调制方式 ASK FSK 13 调制系数/调制误差 调制系数：0.7～0.9 调制误差：-200 kHz～+200 kHz 14 频率偏移 — ±512 kHz 15 编码方式 FM0 MANCHESTER 16 位速率 256 kbit/s 1 Mbit/s 17 位时钟精度 ±100×10-6 ±20×10-6 18 OBU唤醒方式b 15个～17个周期14 kHz方波 15个～17个周期14 kHz方波 19 14 kHz方波唤醒信号精度 ±0.5 kHz ±0.5 kHz 20 OBU唤醒时间 <5 ms <5 ms 21 OBU唤醒灵敏度 ≤-40 dBm ≤-40 dBm 22 OBU接收灵敏度 ≤-50 dBmc ≤-70 dBm 23 OBU最高输入信号功率 ≥-20 dBm ≥-20 dBm 24 OBU同信道干扰抑制比 <+15 dB <+15 dB 25 OBU邻信道干扰抑制比 <+15 dB <+15 dB 26 OBU阻塞干扰抑制比 <-10 dB <-10 dB 27 OBU接收带宽 最大：5.825 GHz～5.845 GHz，最小：5.828 5 GHz～5.831 5 GHz，5.838 5 GHz～5.841 5 GHz 最大：5.825 GHz～5.845 GHz，最小：5.828 5 GHz～5.831 5 GHz，5.838 5 GHz～5.841 5 GHz 28 BER 10×10-6以内 1×10-6以内 29 前导码d 16位“1”加16位“0” 16位“1”加16位“0” 30 后导码 1位～8位 1位～8位 a对应载波2.5倍信道带宽以外。 b RSU强制要求发送该波形；OBU可选择被该波形唤醒或者被正常通信帧信号唤醒。 c OBU接收灵敏度应比唤醒灵敏度高5 dB以上。 d从14 kHz方波唤醒信号结束到前导码开始的时间间隔应不大于72μs。 7上行链路技术要求 上行链路技术要求见表2。 表2上行链路技术要求 序号 参数 A类 B类 1 载波频率 信道1 5.790 GHz 5.790 GHz 信道2 5.800 GHz 5.800 GHz 2 占用带宽 ≤5 MHz ≤5 MHz 3 频率容限 ±200×10-6 ±20×10-6 4 e.i.r.p ≤+10 dBm ≤+10 dBm 5 杂散发射 30 MHz～1 000 MHz ≤-36 dBm/100 kHz ≤-36 dBm/100 kHz 2 400.0 MHz～2 483.5 MHz ≤-40 dBm/1 MHz ≤-40 dBm/1 MHz 3 400 MHz～3 530 MHz ≤-40 dBm/1 MHz ≤-40 dBm/1 MHz 5 725 MHz～5 850 MHza ≤-33 dBm/100 kHz ≤-33 dBm/100 kHz 其他1 GHz～20 GHz ≤-30 dBm/1 MHz ≤-30 dBm/1 MHz 6 邻道泄漏功率比 ≤-30 dB ≤-30 dB 7 天线半功率波瓣宽度 <70° <70° 8 天线极化 线极化或右旋圆极化 线极化或右旋圆极化 9 XPD 最大增益方向 RSUt≥15 dB RSUt≥15 dB -3 dB区域 RSUt≥10 dB RSUt≥10 dB 10 调制方式 ASK FSK 11 调制系数/调制误差 调制系数：0.7～0.9 调制误差：-200 kHz～+200 kHz 12 频率偏移 — ±512 kHz 13 编码方式 FM0 MANCHESTER 14 位速率 512 kbit/s 1 Mbit/s 15 位时钟精度 ±1 000×10-6 ±20×10-6 16 RSU接收灵敏度 ≤-70 dBm ≤-70 dBm 17 RSU最高输入信号功率 ≥-20 dBm ≥-20 dBm 18 RSU同信道干扰抑制比 <+10 dB <+10 dB 19 RSU邻信道干扰抑制比 <-20 dB <-20 dB 20 RSU阻塞干扰抑制比 <-30 dB <-30 dB 21 RSU接收带宽 信道1： 最大：5.787 5 GHz～5.792 5 GHz 最小：5.788 5 GHz～5.791 5 GHz 信道2： 最大：5.797 5 GHz～5.802 5 GHz 最小：5.798 5 GHz～5.801 5 GHz 信道1： 最大：5.787 5 GHz～5.792 5 GHz 最小：5.788 5 GHz～5.791 5 GHz 信道2： 最大：5.797 5 GHz～5.802 5 GHz 最小：5.798 5 GHz～5.801 5 GHz 22 BER 10×10-6以内 1×10-6以内 23 前导码 16位“1”加16位“0” 16位“1”加16位“0” 24 后导码 1位～8位 1位～8位 a 对应载波2.5倍信道带宽以外。 参 考 文 献 [1] 中华人民共和国信息产业部.关于使用5.8 GHz频段频率事宜的通知.信部无[2002]277号.2002-07-02.