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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 20999-2007 Data communication protocol between traffic signal controller and control center. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 20999-2007:
——The terms, such as phase inter green time, phase stage, phase transition constraints and phase stage chain, are added;
——The terms of output channel and clear interval are deleted;
——The content of coordination control is modified as center coordination control and local coordination control;
——Annexes A, B and C specify the communication procedures, status invariants, data tables and data fields;
——Annex D is added for illustration.
This standards was proposed by and is under the jurisdiction of SAC/TC 268 National Technical Committee on Intelligent Transportation Systems of Standardization Administration of China.
The previous edition of this standard is as follows:
——GB/T 20999-2007.
Data communication protocol between traffic signal controller and control center
1 Scope
This standard specifies the requirements for the structure, physical layer, data link layer, network layer and application layer of the data communication protocol between traffic signal controller and control center.
This standard is applicable to the data communication between the signal controller and the control center in the traffic signal control system.
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 15126-2008 Information technology - Open system interconnection - Network service definition
GB/T 17547-1998 Information technology - Open system interconnection - Data link service definition
RFC0768 User datagram protocol
RFC0791 Internet protocol
RFC0793 Transmission control protocol
IEEE 802.2/3: 1985 Ethernet LAN Protocol
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
control center
upper-end device that communicates with, controls and monitors multiple signal controllers in a traffic signal control system
3.2
road traffic signal controller
device that can change the sequence of road traffic signals, adjust the timing and control the operation of road traffic signal lights, which can be referred to as signal controller
3.3
phase
signal sequence consisting of red-yellow-green changes or red-green changes assigned to one or more traffic streams (there is no yellow light for pedestrian light groups)
3.4
offset
difference between the start times or end times of the specified reference intersection and coordinated intersection phases in coordinated control
3.5
signal light group
complete combination of red-yellow-green traffic light for vehicles or red-green traffic light for pedestrians, which corresponds to the output of one phase
3.6
green conflict
specifying that the green signal lights not allowing release at the same time and the green signal lights allowing release at the same time are lit at the same time
3.7
phase inter green time
inter green time between the loss of right-of-way of the previous phase and the gain of right-of-way of the next phase during the signal cycle
3.8
phase stage
status that one or more phases gain the right-of-way at the same time during the signal cycle
3.9
phase transition constraints
constraint rules for phase stage transition
3.10
phase stage chain
sequence of occurrences of a group of phase stage during the signal cycle
3.11
control plan
ordered set of phase setting, stage chain setting and signal timing at intersections
3.12
time table
parameter set in a signal controller indicating the timeslot division and timeslot adoption control mode in a day
3.13
date schedule
table indicating the correspondence between special days (including Sunday) and the used time table in a signal controller
3.14
local control
autonomous control mode of signal controller at local intersection
3.15
center control
mode by which the control center sends commands to the signal controller to control the operation of the signal controller
4 Data communication protocol structure
See Figure 1 for the block diagram of communication protocol structure. The structure includes physical layer, data link layer, network layer and application layer. Each layer, except for application layer, provides various options, and protocols conforming to this standard implement at least one compatible protocol stack from top to bottom. The connection lines in Figure 1 represent the compatibility relationship between connected protocols.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Data communication protocol structure 5 Physical layer 6 Data link layer 7 Network layer 8 Application layer Annex A (Normative) Communication frame structure and specification definition Annex B (Normative) Definition of object identification number Annex C (Normative) Detailed definitions of data classes Annex D (Normative) Communication protocols and message examples Bibliography
交通信号控制机与上位机间的 数据通信协议 1 范围 本标准规定了交通信号控制机与上位机间的数据通信协议的结构、物理层、数据链路层、网络层和应用层的要求。 本标准适用于交通信号控制系统中信号机与上位机间的数据通信。 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（包括所有的修订单）适用于本文件。 GB/T 15126—2008 信息技术 开放系统互连 网络服务定义 GB/T 17547—1998 信息技术 开放系统互连 数据链路服务定义 RFC0768 UDP协议（User datagram protocol） RFC0791 IP协议（Internet protocol） RFC0793 TCP协议（Transmission control protocol） IEEE 802.2/3：1985 局域网协议标准（Ethernet LAN Protocol） 3术语和定义 下列术语和定义适用于本文件。 3.1 上位机 control center 在交通信号控制系统中，能和多台信号机通信并对其进行控制和监视的上端设备。 3.2 交通信号控制机 road traffic signal controller 能够改变道路交通信号顺序、调节配时并能控制道路交通信号灯运行的装置（可简称为信号机）。 3.3 相位 phase 分配给一股或多股交通流的一种由红黄绿变化或红绿变化组成的信号序列（行人灯组没有黄灯）。 3.4 相位差 offset 协调控制中，指定的参照交叉路口与协调交叉路口相位的起始时间或结束时间之差。 3.5 信号灯组 signal light group 一个完整的车辆红黄绿三头灯或行人红绿两头灯的组合，信号灯组对应一个相位的输出。 3.6 绿冲突 green conflict 规定不允许同时放行的绿色信号灯与允许同时放行的绿色信号灯同时点亮。 3.7 相位绿间隔时间 phase inter green time 信号周期内，前一相位失去路权和下一相位获得路权之间的绿间隔时间。 3.8 相位阶段phase stage 信号周期内，一个或多个相位同时获得路权的状态。 3.9 相位阶段过渡约束 phase transition constraints 相位阶段进行转换的约束规则。 3.10 相位阶段链 phase stagechain 信号周期内，一组相位阶段的出现序列。 3.11 控制方案 control plan 路口关于相位设置、阶段链设置、信号配时的有序集合。 3.12 日计划 time table 信号机内表示一天中的时段划分及时段采用控制方式的参数集合。 3.13 调度表 date schedule 信号机内表示特殊日（包括周日）与所用日计划的对应关系的表格。 3.14 本地控制 local control 信号机本地路口的自主控制方式。 3.15 中心控制 center control 上位机向信号机发送命令控制信号机运行的方式。 4数据通信协议结构 通信协议结构框图见图1。该结构包含物理层、数据链路层、网络层、应用层。除应用层外，每一层提供了多种选择方案，符合本标准的协议至少实现从上到下的一个相容协议栈。图1中的连线表示相连的协议间兼容关系。
