China’s first V2X application layer standard released
19 September 2017
The first standard designed for the V2X (vehicle-to-everything) application layer in China has been officially released. The standard (T/CSAE 53-2107) was developed by a working group led by General Motors, together with Tsinghua University and Chang’an Auto, with the support of the China Industry Innovation Alliance for the Intelligent and Connected Vehicles.
As one of the group standards under SAE-China, the new standard provides a framework that is independent of basic communication protocols, enabling different automakers to develop interoperable V2X applications for data interaction. It offers a mechanism for automakers to use a single communication technology for the development and commercialization of all V2X applications.
It has standardized data sets and the data exchange interface, laying the groundwork for the standardization of V2X application development and testing by defining data interaction for different vehicle brands adopting V2X systems.
The standard has identified 17 China Day One V2X applications covering safety, efficiency and information service. It specifies the 17 applications in six aspects:
- Application definition
- Main Scenes
- Fundamental system principles
- Communication modes
- Basic performance requirements
- Data interaction
As a result, the standard is able to sort out each application according to varying needs for communication frequency and time lag.
The standard also defines the application layer’s data set. The data set for the application layer is built on a three-layer, interoperable structure consisting of an information set, data frames and data elements. Using ASN.1 abstract syntax as a definition, the data set is compatible with multiple platforms and programming languages.
The data set’s encoding and decoding process, which is based on Unaligned Packet Encoding Rules (UPER), effectively compresses the size of data packets in air-interface communication. Further, the data set takes into consideration its expandability and compatibility with well-established standards such as SAE J2735. It also encodes basic safety, road, traffic light, brake control and lane use information into a series of data sets that the V2X system can download for use.
The data interaction standard and interface are defined by the standard as well. Supported by a data interface based on a unified data set for application layers, the standard can be used in a variety of transport layers, network layers, data link layers and physical layers. It caters to increasingly diverse and continuously improving communication technologies.
With the support of automakers, parts and components manufacturers, information and communications technology companies, and research institutions, the standard has already been partially adopted in China. This is paving the way for its nationwide use.
China’s Ministry of Industry and Information Technology (MIIT) has included the standard in the LTE-V Wireless Transmission Technology Standardization and Prototype Development and Testing project. MIIT is using the new standard as a reference for a selection of V2V and V2X applications under development, covering telematics services such as BSM, MAP and SPAT. These applications are currently undergoing simulation and real-world testing. Being part of the project will open the door for the standard to make improvements and quickly gain ground in China.
GM has been a leader in developing intelligent V2X technology for more than a decade. We are pleased to have brought our latest global achievements to China to promote its local development. We have had the honor of leading the working group for the development of a flexible V2X application layer standard for China together with Tsinghua University and Chang’an Auto. This standard is designed to support various communication protocols at the same time, as well as future evolving technologies such as 5G.—Dr. John Du, director of the GM China Science Lab