Conformance Assessment: A Safe Channel for Successful C-V2X Deployment

By Holger Rosier, Rohde & Schwarz GmbH & Co. KG

The introduction of seatbelts, airbags and crumple zones in cars has contributed greatly to saving lives on the road over the past few decades. Today’s advanced driver assistance systems (ADAS) and future autonomous driving solutions will go some way to further reducing the number of accidents on highways, but their impact will remain limited without a holistic view of all road users.

Even the most focused driver can’t react to an incident that’s happening directly in front of them or lurking behind a sharp curve. But our fellow road users, such as drivers, cyclists and pedestrians, can share their vision, allowing us to react accordingly. This is the future that vehicle-to-everything (V2X) communications are creating for road users. Like other technologies, V2X requires unified standards to ensure that everyone implements it in the same way. But who will ensure that standards are met? Are there previous experiences that can provide us with the right approach?

The key to ensuring that automated and cooperative driving become a reality and that systems developed by different automakers and their suppliers interoperate is standards. Standards for V2X communications are defined by extensive documents covering everything from radio access technology to the infrastructure and application layers. Globally, various standards for Intelligent Transport Systems (ITS) have been developed significantly. These standards include Wireless Access in Vehicular Environments (WAVE) in the United States and ETSI ITS-G5 in Europe, as defined in the IEEE 1609 standard series. All of these standards are based on an extension of the WLAN standard, namely IEEE 802.11p. At the same time, the Third Generation Partnership Project (3GPP), which operates on standards at the global communication level, also enables ITS to operate over cellular network technology and utilize existing commercial mobile network technologies. Device-to-device (D2D) communications using this technology do not require any mobile network infrastructure. The provisions of this standard were first introduced in the R12 version of the standard in 2015 and further improved in the 3GPP R14 version (also known as LTE V2X  ) in 2017 to support the communication needs of cellular vehicle-to-everything (C-V2X). In fact, the Internet of Vehicles (IoV) currently implemented in China adopts the standards developed by multiple organizations including the Society of Automotive Engineers of China (SAE-C) and the C-V2X standard.

Overall, C-V2X is an excellent technology that allows all road users, from pedestrians to motor vehicles, to share vehicle and highway status information with traffic infrastructure while also providing Internet and cloud services. Since the technology is built on the 4G LTE cellular network technology that is currently widely deployed, and the 3GPP standard also includes a roadmap for future  5G  network upgrades with higher bandwidth and lower latency, future compatibility has been incorporated. In addition, the necessary wireless communication chipsets and test equipment for proving interoperability are already in common use.

There is one important aspect of C-V2X that needs to be addressed here. For the foreseeable future, many communications will continue to be based on 4G LTE. As network infrastructure is deployed and 5G support is imminent, some cellular vehicle-to-network (C-V2N) communications may transition to 5G. However, all other V2X functions, such as vehicle-to-pedestrian (V2P), vehicle-to-vehicle (V2V), and vehicle-to-infrastructure (V2I), will continue to be tested and approved under the existing 4G LTE standard for the foreseeable future.

The birth of C-V2X also highlights the huge amount of collaboration required to develop such standards. Some of this work has been supported by government subsidies to study how to best address the challenges of ITS solutions. Organizations such as 3GPP have also laid the foundation for cooperation to ensure that cellular phones can be used normally around the world. Now, a new organization has been established to ensure that the automotive industry and wireless technologies closely related to C-V2X can meet the needs of various industries.

The 5G Automotive Association (5GAA) is a cross-industry organization comprised of key automotive and telecom industry representatives. Since its inception, the Alliance has brought together the world’s most important industry representatives to ensure that the next necessary stage of integrating automotive solutions with telecom technologies is smoothly advanced. The Alliance’s working groups delve into a range of issues, covering high-level topics such as business models and go-to-market strategies, as well as specialized discussions such as technical requirements and system architectures. The working groups also conduct assessments and drive large-scale trials to ensure that technology concepts have the opportunity to be tested in the rigors of real highway environments . These initiatives have resulted in a series of comprehensive white papers and studies that provide insights into the technical foundations of C-V2X.

Testing is a necessary step before releasing any product, accompanying the product from the R&D laboratory to the post-production terminal test. Obviously, one of the key points of testing is to ensure that the equipment operates within the range specified by the standard. For telecommunications equipment, this includes the RF level, as well as the various protocol tests supported by the equipment. As a leading supplier in the mobile and wireless communication industry, Rohde & Schwarz's test solutions provide industry-leading support for this field. Over the years, Rohde & Schwarz's software and its fast and convenient configuration of hardware test equipment to test the powerful functions of various types of terminal equipment have become Rohde & Schwarz's unique advantages.

Of course, the interaction between individual C-V2X solutions and the reference system defined by the test equipment is a necessary benchmark test that needs to be carried out. However, there is still the question of interoperability. The global success of the wireless communication standards developed by 3GPP is partly due to the unified testing procedures it has established.

In fact, after years of development, the Global Certification Forum (GCF) has become the adjudicator of standards conformance. The first phase requires independent testing of handsets and modems for relevant RF and protocol standards conformance. The second phase includes the evaluation of handsets in operator acceptance testing. This testing includes performance benchmarking and verifying that various network functions can operate as expected. As cars are basically equipped with connectivity and are expected to operate seamlessly with other mobile nodes in different countries and regions around the world, procedures for such testing of C-V2X components and electronic control units (ECUs) should also be taken into consideration.

5GAA is working to promote a unified test plan for C-V2X conformance assessment. For the telecommunications industry, conformance assessment can be divided into conformance testing of specific communication protocol layers and interoperability testing applied to terminal devices. Such an approach includes unified test steps, a set of minimum requirements, and the selection of appropriate test partners. The radio access layer must be required to comply with the global 3GPP standard, while the upper application-related layers can be tested according to regional standards. In terms of regional division, the most likely scenario will be the European Union, the United States, and China.

C-V2X has unlimited potential to significantly improve pedestrian safety and solve traffic problems. Rohde & Schwarz participates in many standardization organizations, councils, groups and advisory committees to contribute its insights and support for the necessary technologies to achieve the vision of zero accidents on roads and highways. As ITS and C-V2X move from ideal to reality, we will continue to use our unique insights, knowledge and experience to build bridges for cooperation between the global automotive and telecommunications industries for the benefit of all road users.

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