DSRC vs. C-V2X
DSRC vs. C-V2X for Safety Applications
General
For the past several years, DSRC has been the only V2X technology available. After a long period of multiple large-scale field tests, DSRC based V2X went into production in Japan in 2015 and in the US in 2017 in selected vehicle models. In 2019, VW released its Golf 8 with DSRC based V2X, making Europe’s most popular car the first mass market vehicle with V2X.
The more recent C-V2X technology has the same purpose of direct communication link between vehicles. C-V2X is defined by 3GPP based on cellular modem technology, leading to fundamentally different non-interoperable access layer with DSRC. Aside from that, the two technologies are addressing identical use-cases and having identical network, security and application layers.
While DSRC-based V2X is deployed in Europe and Japan, C-V2X is gaining momentum in other regions. In the US, thousands of Road Side Units were equipped with DSRC V2X and OEMs began planning their deployment. The industry is watching the FCC as it plans to divide the allocated 5.9GHz band between V2X and WiFi. China, on the other hand, is moving ahead with the deployment of C-V2X. In early 2020, Autotalks chipset was selected for a mass production C-V2X program in China.
The table highlights the commonalities and differences between the usability and general properties of DSRC and C-V2X.
Technical
DSRC and C-V2X are rooted from different technologies, leading to fundamentally different operational methods. DSRC, derived from WiFi, is optimized for cost and simplicity, and inherently supports distributed operation. C-V2X, derived from LTE, added new mechanisms to enable distributed operation (mode 4).
The comparison is multi-dimensional. The impact of every parameter should be analyzed according to the properties of V2V operation, as defined by the requirements of the V2V upper-layers and applications.
The following table summarizes the technical properties of DSRC and C-V2X technologies:
