Competing V2V Technologies Emerge, Create Confusion

Vehicle-to-vehicle communication is widely anticipated, but how to put the technology to use is unresolved.


The battle over vehicle-to-vehicle communications technology has begun, as governments step back to see which of two main competing standards and lots of related technology are best suited for reducing accidents.

V2V is an often-discussed wireless communication protocol that enables vehicles to communicate with each other, easing traffic congestion, avoiding accidents, and ultimately improving transportation safety. Using V2V, vehicles exchange information such as the speed, location, and directions they are heading. Exchanging these messages up to 10 times per second within 300 meters, vehicles can obtain a 360-degree “view” of their environment and proximity to other vehicles. V2V can warn drivers about collisions ahead, lane departures, rear cross traffic, blind spots, as well as slippery road conditions.

“While onboard sensing has advantages and limitations, as does smart city infrastructure, V2V communication completes the layered situational analysis necessary for navigating complex urban environments,” said David Fritz, vice president of hybrid and virtual systems at Siemens Digital Industries Software. “V2V complements smart city infrastructure and onboard sensing for a holistic understanding of the environmental state at any point in time, enabling complex and accurate decision-making for safety and improved efficiency.”

There is little debate about the value of V2V. The U.S. National Highway Traffic Safety Administration (NHTSA) concluded that 615,000 motor vehicle crashes in 2020 could have been prevented using V2V, which enables each vehicle to utilize a network of sensors within 300 meters. A V2V-equipped vehicle would be able to reduce speed automatically using ADAS, for example, when there is an accident ahead, independent of any knowledge the driver may have of the accident.

Imagine a situation where an emergency vehicle is approaching a busy urban intersection and buildings block its view by other vehicles approaching the intersection from another direction.

“Onboard sensing will not allow the other vehicles to detect the emergency vehicle approaching,” Fritz said. “Smart city infrastructure can only control the stoplight at the intersection and broadcast that an emergency vehicle is approaching. However, the emergency vehicle being able to tell the vehicles around it, ‘I’m here and I need to pass,’ is a V2V feature.”

The auto industry and the U.S. Department of Transportation (USDOT), the parent organization of the NHTSA, want to add even more vehicle communication technology. They are looking beyond V2V to vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), and vehicle-to-network (V2N), commonly known as vehicle-to-everything (V2X). NHTSA has done extensive research on V2V. In 2014, the administration released a detailed research report on the subject, but since then has hedged its bets while it waits to see how this nascent technology progresses.

Fig. 1: Using V2V, cars exchange information on speed, location, and direction the vehicle is heading. Source: Infineon

V2V market potential
The V2V communication market is forecast to grow at a 13.3% compound annual growth rate to $32.9 billion in 2026, up from $19.98 billion in 2022, according to The Business Research Company. The research took into account the technologies supporting LTE-V2X, LTE modem with V2X integration, vehicle-to-vehicle (V2V), and vehicle-to-infrastructure (V2I) communications. (Sometimes V2I is referred to as vehicle-to-roadside infrastructure).

OEMs supporting V2V include Audi, Mercedes-Benz, General Motors, Toyota, Volkswagen, Ford, Nissan, and Honda. Technology companies such as Qualcomm and Cisco also are heavily involved. They will likely be the ones to work out the bugs and best path forward for implementing this technology, and there is much work to be done.

For example, the automotive industry has not agreed upon a definitive path of deployment for V2V. In addition, while Dedicated Short-Range Communications (DSRC) works well within a 300-meter range, it requires a majority of the vehicles nearby to have the same DSRC-based systems. In order for this to happen, legislation will need to be in place and enforced. So far, no legislation followed the release of the NHTSA 2016 document, leaving the door open for competing V2V technologies.

Starting in 2017, USDOT changed its focus from legislation to supporting the transportation industry with pilot programs, case studies, and lessons learned. Currently, there are three major pilot programs underway in New York City, Wyoming, and Tampa, Florida.

The V2V communication protocol uses a DSRC channel on the 75 MHz band of the 5.9 GHz spectrum the FCC has allocated for Intelligent Transportation Systems (ITS) vehicle safety and mobility. This protocol is based on the IEEE 802.11p standard, wireless access in vehicular environments (WAVE), also known as WLAN-V2X. (Wi-Fi is a good example of WLAN, which stands for wireless local area network.)

But since DSRC was introduced, a new V2V technology has emerged. Qualcomm proposed a cellular vehicle-to-everything (C-V2X) protocol with its own chipsets. Initially, the auto industry and regulators were supportive of DSRC, and Toyota started to implement DSRC. But as more and more developers join the C-V2X camp, some OEMs shifted direction. Even though Ford has been investing in both technologies, it decided to support C-V2X.

What is C-V2X?
While the DSRC peer-to-peer technology operates like Wi-Fi, C-V2X technology (as defined by 3GPP Releases 14, 15, 16) relies on cellular networks such as LTE and 5G. C-V2X uses the unlicensed 5.9 GHz band.

In the past any peer-to-peer protocol relying solely on cellular networks would have had too much latency to function properly. The direct vehicle-to-vehicle C-V2X protocol has changed that, and it functions just like DSRC. The indirect C-V2X has the added benefit of communicating with vehicles on a broader scale, as long as vehicles can communicate with LTE or 5G signals. Initially, the 3GPP Release 14 defined the use of LTE for C-V2X. Releases 15/16 added the use of 5G and 5G NR. The term “direct” refers to communication functioning in a peer-to-peer manner, in which vehicles can talk directly, while “indirect” refers to communication using the LTE or 5G networks.

So far, C-V2X is taking the lead in the U.S. and China, while DSRC or WLAN-V2X is popular in Japan and Europe. Because DSRC and C-V2X are not interoperable, some chipmakers provide dual-mode solutions supporting both protocols.

Companies investing heavily in C-V2X include Qualcomm, LG Electronics, Huawei, Ericsson, NTT Docomo, Ford, Oppo, Samsung, Intel, and General Motors, according to GreyB. Interestingly, most of the players here are electronics companies, and only two are automakers. Companies with the most research patents for WLAN-V2X include LG, Toyota, Ford, Huawei, Denso, General Motors, Hyundai, Volkswagen, Qualcomm, and Honda.

Additionally, many chip and module developers are getting ready for the mass market to emerge. Some of the C-V2X suppliers include ALPS ALPINE, Autotalks/STMicroelectronics, Fibocom, Murata, NXP, Quectel, Rolling Wireless, Titan Automotive Solutions, u-blox, Wistron NeWeb, and ZTE.

GSMA, an industry consortium with members and regional offices worldwide, is a strong supporter of C-V2X. Their members include operators of mobile network, satellite, aircraft, maritime, telecommunications, and regulatory bodies. Additionally, industry members include handset and device makers, software, equipment, and Internet providers.

Another strong supporter of C-V2X is the 5G Automotive Association (5GAA). The association was founded in 2016 by global and cross-industry organizations, including Audi, BMW, Daimler, Ericsson, Huawei, Intel, Nokia, and Qualcomm. Its objective is to encourage the cooperation of companies from the automotive, technology, and telecommunications industries (ICT), to develop end-to-end solutions for the mobility and transportation industries.

Examples of V2V/V2X chips
Qualcomm offers a C-V2X ASIC compatible with 5G that supports ADAS sensors operated at the 5.9 GHz ITS spectrum, as well as in direct peer-to-peer mode. It supports 3GPP LTE-V2X (PC5) and meets the GNSS Standards (Beidou, Galileo, GLONASS, GPS). The C-V2X ASIC will have similar security and privacy functions compared to 802.11p based DSRC protocols.

Partnering with STMicroelectronics, Autotalks offers a dual-mode chip that integrates the dual-core Arm Cortex-A7 and the V2X-embedded Hardware Security Module (HSM). It supports dual channel/diversity IEEE 802.11p, the C-V2X direct communications (PC5) protocol. The Autotalks chip also supports Release 14/15 mobility-optimized modems as well as the IEEE 802.11a/b/g/n/ac operation at 2.4 GHz/5 GHz.

A big challenge is to increase the design process efficiency of V2V-related hardware and software. “Early in the process, low-fidelity models of hardware architectures along with early software implementations are the place to begin. As configurations are discarded while others are reinforced, higher-fidelity models are required to better refine the key metrics that will strongly impact the final solution,” Fritz said, noting at that point low-fidelity models are incrementally replaced with semiconductor IP (SIP or RTL). “Then, most commonly, CPU subsystems that incorporate CPUs, interconnect, interrupt, and memory controllers from IP vendors such as Arm are needed. Further fidelity comes when SIP replaces accelerators like GPUs and NPUs. At that point, very accurate power and performance details of the final hardware running production software can be conducted.”

Deployment issues
Even though V2V has been in development for more than 20 years, the technology has not reached the mass market — but not because of lack of products. For it to function effectively, enough vehicles on the road within a 300-meter radius of one another must have V2V installed. Today, there are not enough viable statistics to determine how well DSRC technology is working. Both DSRC and C-V2X are competing for the attention of the same OEMs with a focus on return on investment. This will further delay V2V reaching critical mass.

The biggest problem is a lack of legislation. Unless OEMs are required to implement V2V, as was the case with the federal seat belt legislation introduced in 1968, they will have to figure things out on their own. That has opened the door to companies like Qualcomm, which are taking the lead to drive demand.

With V2V, vehicles will be connected more than ever. The mighty computer within the progressively autonomous vehicle will need to handle data from sensors, networks, V2V/V2X, and security. With this deluge of data come privacy and cybersecurity concerns. Fears that V2V will just be another hacker target are growing. For example, where will encryption be done? Will hackers take advantage of buffer overflow due to the large amount of data going back and forth between vehicles and networks? Additionally, there are infotainment, in-cabin monitoring, and ADAS management. Will user information, location, and other private data be tracked? All these will be part of the V2V and SDV design considerations.

Technology integration in vehicles is complex. V2V, ADAS, SDV, smart sensors, and wireless connectivity all need to work together. For example, if V2V is used in ADAS applications such as speed reduction, it’s important that the system design for overall functional safety works. Future vehicle design will be even more complicated, and ensuring safety is always a top priority. In fact, the ISO 26262 standard requires proof that the automotive software and hardware really do what they are designed to do.

“In chip development, safety-compliant tools and flows need to be used that also allow safety engineers to capture the safety intent by leveraging the Unified Safety Format (USF),” said Robert Schweiger, group director for automotive solutions marketing at Cadence. “Once the RTL design is finished, it will then be synthesized to generate the gate-level netlist, including safety-specific logic, before final layout. But how do you know that the synthesis is done correctly and that it will have exactly the same functionality that has been written in RTL? This is why we provide a logic equivalence check as part of our digital safety implementation flow to ensure that the gate-level netlist will perform the same functionality as was written in RTL. The whole process can be very complex. That is why you need to find the right tool to do the job correctly.”

The future of V2X
DSRC and C-V2X will continue to evolve. Which will win has yet to be decided. Both camps have support from OEMs and technology companies globally. At the moment, however, it appears C-V2X has the backing of industry heavyweights, including 3GPP, GSMA, and 5G, which may give C-V2X an advantage over DSRC. But only time will tell if one technology will dominate the industry or if they would co-exist.

At the federal level in the United States, a $1.2 trillion infrastructure bill was approved. Within the bill, there are specific mentions of DSRC and C-V2X. How much funding DSRC and C-V2X actually receive may indicate which one is prioritized. Most technology developers say 2023 and 2024 will be the year that OEMs will be deploying V2V. 5GAA believed that 2023 would be a pivotal year for V2X deployment. But this is still early days for the technology..

“V2V will continue to evolve into V2X,” said Frank Schirrmeister, vice president of solutions and business development at Arteris IP. “Beta projects like the one in Ann Arbor, Michigan, show how in the future vehicles and traffic lights will be able to communicate with each other to reduce traffic jams. For example, when the traffic lights sense more cars are coming from one direction, they will stay green longer, allowing more vehicles to go through. Even more importantly, when an emergency vehicle like an ambulance needs to pass through multiple traffic lights, it will be able to send an alert signal in advance so that the traffic lights stay green to allow the emergency vehicle to take priority.”

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