Using DSRC as a V2X technology

Article By : Junko Yoshida

Qualcomm execs Malladi and Flore continue the interview, comparing DSRC and cellular V2X, both of which are part of the company's strategy.

« Previously: Qualcomm on DSRC: Has it reached a dead end?

EE Times discussed LTE Direct as part of Qualcomm's V2X solutions on the previous page. Qualcomm executives explained that while the cellular technology is promising, it is currently not in high demand.


DSRC vs. cellular

Yoshida: But what makes you think DSRC isn’t better than cellular when it comes to V2X?

Malladi: DSRC was developed more than 10 years ago. It was the state of the art then. DSRC has done a great job in defining V2V specifications for messaging, forward collision warnings, emergency braking warning for slippery roads, etc. But… the development work of DSRC is already finished. There is no follow-on work. DSRC is a dead end.

On the other hand, cellular-V2X continues to improve as cellular technology progresses. For example, you can use LTE Direct safety applications without significant latency. It’s ideal when you don’t have time to go to the network. By leveraging advanced coding technology, it offers better protocols compared with what was possible 10 years ago.

[Qualcomm pits C-V2X vs DSRC Original cr]
Figure 3: Qualcomm compares Cellular-V2X against DSRC, both included in the company's strategies.

Yoshida: I get the evolution of cellular standards. But where are we today when it comes to the LTE-based V2X standard?
Flore: The cellular-based V2X standard lives under the umbrella of 3GPP. As for LTE-based V2X, 3GPP just completed in September the initial cellular V2X standard for inclusion in the Release 14.

Yoshida: You described it as “initial.” Does that mean it’s not completely done?
Flore: We focused on the basic safety features for Vehicle-to-Vehicle (V2V) communications in the work we finished in Sept. We are, however, making further enhancements to support additional V2X operational scenarios. We plan to get that work completed in March 2017 — to be included in Release 14.

Yoshida: What are included in that initial decisions for C-V2X — in the context of R14?
Flore: The Sept. drop was all about basic safety features. They are now matching those offered by DSRC. A new device-to-device (D2D) interface was introduced so that it’s enhanced for vehicular use cases, addressing high speed and high density.

Yoshida: What are you planning to incorporate in the second drop [scheduled for March, 2017]?
Flore: We are bringing some of the advanced features such as platooning, enhanced data link, use of positioning.

Yoshida: With all due respect, NXP, for example, was showing off DSRC-based truck platooning on Munich roads during Electronica.
Flore: We’re talking about a large type of platooning nodes, which can run much closer together, capable of relaying information [in] multiple hops.

Yoshida: Under the 3GPP initiative, how do you plan to enhance Cellular-V2X in the upcoming Release 14 to Release 15 (Sept., 2018) and eventually R16 (March, 2020)?
Flore: I don’t think we are rolling out any new radio for V2X in R15. The focus of R15 is more on mobile use cases and application. Under this roadmap, the new 5G radio for V2X will emerge in Release 16, where more powerful V2X features will be added while maintaining the compatibility with the previous generation of Cellular-V2X.

[Editor's note: After this story was posted, Qualcomm spokesman stressed that the company is pursuing a dual strategy — supporting both DSRC and C-V2X. The following is the company's statement.

Qualcomm supports and promotes both 802.11p (DSRC/ITS-G5) and Cellular-V2X. They both leverage the upper layer investments made into SAE and ETSI by the automotive industry.

Qualcomm has made a second generation [DSRC] chip commercial now, and we have plans for subsequent solutions using our industry leading 802.11 products.

Cellular-V2X is primarily a radio upgrade to 802.11p, leveraging all the modem enhancements in cellular domain over the past decade, thereby offering new capabilities, performance enhancements andmoving forwards, a strong evolution to 5G. With expertise with both radios and the upper layer stacks, Qualcomm is uniquely capable of building a multi-radio system with coexistence capabilities of 802.11p and Cellular-V2X if the automotive ecosystem ever requires it.

This interview was first published by EE Times.

Leave a comment