Ron DiGiuseppe, Automotive IP Segment Manager, Synopsys
Ron DiGiuseppe, Automotive IP Segment Manager, Synopsys
Today, millions of vehicles connect to cellular networks for real-time navigation, connected infotainment, and emergency services; however, new cellular networks, like 5G, will enable additional applications such as autonomous driving, Vehicle-2-Vehicle (V2V), Vehicle-2-Infrastructure (V2I), Vehicle-2-Network (V2N), and Vehicle-2-pedestrian (V2P) communications. 5G’s increased throughput, reliability, availability, and lower latency will enable new safety-sensitive applications which are holistically known as V2V/V2I (V2X or Vehicle-to-Everything) (Figure 1). Starting with Release 14, the standards organization, 3rd Generation Partnership Project (3GPP), added the direct communications functionality as part of the new cellular standard that will ensure V2X applications. As Cellular Vehicle-2-Everything (C-V2X) technology progresses, collaborations with city governments, cellular providers, chipset suppliers, and roadside units (RSU) equipment makers are starting commercial trials to enable near-term adoption of C-V2X applications. As a key enabler of C-V2X technology, 5G radio, SoCs, and high-performance IP solutions become critical components for the success of 5G C-V2X.
5G C-V2X provides a common wireless network to support convergence of multiple applications for urban, suburban, and highway driving conditions. 5G C-V2X will enable multiple new automotive applications ranging from collision avoidance and safety systems (V2V), traffic signal timing/priority (V2I), real-time traffic/routing and cloud services (V2N), and safety alerts to pedestrians/bicyclists (V2P). Benefits of C-V2X technology for safety applications are highlighted in Table 1:
To utilize 5G for C-V2X applications, 3GPP has introduced new capabilities to the 5G standard. In contrast to 4G LTE, 5G specifies one millisecond (ms) end-to-end transmission latency requirements which is needed when minimizing the V2X communications reaction time. The existing 4G LTE system has various limitations preventing 1ms end-to-end transmission such as the 1ms length of subframes. The 1ms length subframes will cause 4G LTE to exceed the 1ms end-to-end transmission requirement just to transmit the data, excluding delays through the network and processing time. In addition to low latency, 5G improves network reliability by limiting packet loss which is required for safety-critical V2X services. Finally, 5G’s high bandwidth data rate of up to 20 Gb/s is required to support real-time mapping for automated driving, software updates, and streaming multimedia infotainment.
5G C-V2X applications must meet well-defined performance metrics while operating in a variety of environments that 5G radio and processor semiconductor SoC suppliers are currently testing 5G C-V2X technologies and comparing them against alternate V2X radio formats such as Dedicated Short Range Communications (DSRC) technology which is based on IEEE 802.11P. DSRC technology was previously identified by the U.S. National Highway Traffic Safety Administration (NHTSA) for V2X applications but the US Department of Transportation (USDOT) has postponed the proceedings to mandate DSRC while the industry committee completes the introduction of C-V2X. During the 2018 keynote at the International Symposium on Advanced Radio Technologies, Heidi King who is the deputy administrator at NHTSA stated, “USDOT remains technology-neutral relative to communications protocols that support V2X technology.” Furthermore, Ms. King stated, “our historical research focused on DSRC because that was the only technology available … but we are also working with industry partners to explore the new, emerging cellular V2V (C-V2X) capabilities.” 1 While the industry implements DSRC and C-V2X protocols, different regions are adopting each technology, and the tier 1 automotive and semiconductor suppliers are adding both protocols to various products.
Industry stakeholders are evaluating 5G C-V2X operational capabilities in multiple test environments to verify performance and compare against DSRC as an alternative. 5G Automotive Association (5GAA) is a global, cross-industry organization of companies from the automotive, technology, and telecommunications industries, working together to develop end-to-end solutions for future mobility and transportation services. The 5GAA presented the test results in a paper published in October 2018 titled: “V2X Functional and Performance Test Report; Test Procedures and Results” 2. In the test report, 5GAA compared C-V2X and DSRC in line of sight scenarios and non-line of sight test cases in a combination with WIFI and adjacent DSRC signals. The test measured effective range at 90% reliability. The results are shown in the Table 2.
As previously stated, collaborations with city governments, cellular providers, chipset suppliers, and roadside unit (RSU) equipment makers are starting commercial trials to enable near-term adoption of C-V2X applications. Figure 2 shows the timeline for C-V2X deployment as published by 5GAA. 3GPP Release 14 (R14) was a key step for C-V2X deployment since it added network communication improvements, increased data volumes, managed greater scale of connected devices, and provided reduced latency and higher levels of reliability. 3GPP Release 16 (R16) will provide enhancements in bandwidth, latency, reliability, and enhanced safety.
Semiconductor suppliers like Qualcomm have announced SoCs such as 9150 C-V2X chipset and reference design with integrated GNSS capabilities for accurate positioning, an application processor to run the Intelligent Transportation Systems (ITS) V2X stack, and a Hardware Security Module (HSM) to provide secure V2X communications. On January 7, 2019, Qualcomm announced3 a collaboration with the city of Las Vegas, Regional Transportation Commission of Southern Nevada, and RSU supplier Commsignia to implement a C-V2X trial. The trial is the first public installation of C-V2X in Las Vegas. It uses Commsignia’s on-board units (OBUs) and RSUs at nearly 100 intersections throughout the city along with vehicles equipped with C-V2X aftermarket OBUs to demonstrate V2I use cases, including traffic messaging to vehicles. As V2X trials progress, industry stakeholders are planning the rollout of V2X infrastructure while automotive tier 1 designers and automakers are planning the adoption of C-V2X modules. Semiconductor SoCs implementing C-V2X functions are critical to successful trials and industry rollouts. It is very critical to enable such function with the optimal processor, analog IP, and interface IP solutions.