中文
The promise of vehicle-to-everything (V2X) communications is to transform transportation. Improved safety? Better traffic efficiency? Cleaner environments? Expectations are high.
The global market is veering toward cellular V2X (C-V2X), expecting even greater connectivity ubiquity and the opportunity to drive down deployment costs. After all, leveraging already deployed cell towers is faster and a lot cheaper than purpose-building Wi-Fi-based 802.11p DSRC tech into existing infrastructure. Plus, with China standardizing on C-V2X, there will be no shortage of substantive learnings that the rest of the world will be able to integrate into planned offerings and trials.
C-V2X is not without its challenges
As 5G and 4G/LTE converge, ensuring smooth handoffs of critical connected vehicle data between these two network types will be important. For example, in areas with heavy traffic congestion, ability to scale becomes an issue if a high volume of vehicles attempts to transmit and receive data at the same time. Then there’s the challenge of meeting stringent latency requirements that come with safety-related applications. On this front, fractions of a second can quite literally make the difference between life and death. On top of this, security of networks, infrastructure and devices supporting C-V2X will necessitate unrelenting diligence.
After more than a decade of planning, trials and standards development, the V2X rubber is finally set to meet the real road – with no room for errors. Now, a question on the minds of stakeholders is how to make sure rollouts are trouble-free.
Playing a key role will be advanced test strategies that can diagnose issues and root causes with pinpoint accuracy.
Designing a road ready testing strategy
Spirent has worked closely with OEM car manufacturers, research institutions, component providers and network operators to design C-V2X testing strategies that will provide the most accurate indications of road readiness in these important areas:
Interoperability – Technology that has evolved over 15+ years across geographies and among global participants adhering to multiple standards bodies will need to undergo stringent interoperability testing to ensure it can live up to the true promise of “vehicle-to-everything.”
Performance – Data latency is tolerated for most applications in our daily lives but can thwart real-time C-V2X communications. That’s because transportation safety and efficiency hinges on split-second decision making and reactions. Vehicle makers, governments, drivers and passengers alike need to be confident in the technology supporting them. Any failures in the field could set adoption back years. To this end, latency-based performance testing and validation must span across radio components, signals and multilayer protocol stacks.
Security – Even more than performance, hacking attempts by evil actors (potential attackers) could pose serious safety and data privacy risks on users. Therefore, C-V2X infrastructure and equipment must ensure privacy of data communication, giving drivers the confidence that their safety is never compromised and personal data will not be used fraudulently.
Proving connected vehicles are safe before they hit the road
C-V2X introduces an entirely new dynamic with mission critical performance demanded from devices that are constantly moving, including between networks. Connected vehicles are also considerably more difficult to test in actual driving and connectivity conditions. This creates a paradox of sorts because before vehicles can be trusted on the road, they must prove they are safe to operate there.
With this in mind, Spirent recommends a testing strategy defined by the following key phases:
Conformance testing – A prerequisite for interoperability and later stage testing phases, conformance testing provides a basic view of the system’s capabilities. As part of this phase, certification testing is conducted to ensure correct implementation of standard specifications defining the technologies. This ensures products from different vendors will interoperate as intended. This testing is generally conducted in lab-based environments and is not an indication of what to expect on the road.
Application testing – After assuring correct implementation of base standards, end user applications set for deployment must be validated to ensure functionality and performance. This means testing scenarios such as Intersection Collision Warning (ICW) and Forward Collision Warning (FCW) that involve vehicle-to-vehicle message delivery. Here, the focus is on testing the behavior of the involved vehicles, and performance of the apps and systems that support the overall C-V2X experience.
Benchmark testing – It is important to measure and compare the ability of C-V2X equipment and infrastructure to address key performance challenges that may exist between interoperable network components. Depending on the stage of development in the product lifecycle, testing approaches will need to adapt. Software-based simulations will initially be used for early prototyping in accordance with Modern in the Loop (MiL) and Software in the Loop (SiL) setups. Iterative development will eventually prep solutions for Hardware in the Loop (HiL) testing.
Network testing – It can be challenging for stakeholders to access live 4G and 5G networks to test under real-world conditions. 5G digital twins are being used instead as they provide sandboxes for extensive testing under realistic conditions and traffic loads. This supports extended testing under virtually any scenario, including simulation of security attacks and network outages.
Field testing – After a vehicle and its supporting technology and network infrastructure have proven they can successfully perform V2X application scenarios in controlled lab environments, they can finally be introduced to real world field testing. This is where every detail is scrutinized to determine mass market readiness.
In future posts, we will dive into greater detail about what happens at the key phases of C-V2X testing covered here. In the meantime, read the white paper How should the automotive industry test V2X systems? It reveals how to create robust and reliable systems capable of recognizing when they are under attack.
