How will 5G and connected cars spark?
업데이트 시간: 2021-05-05 13:54:27
Quality of Service (QoS) requirements for automotive networks are in the areas of latency, data rate, reliability and communication distance. In recent years, emerging automotive network applications and use cases such as V2X have made some headway, and they are certainly placing more stringent requirements on QoS as described above. As for self-driving cars, developers tend to focus on camera, radar and LiDAR sensor technologies, but the already existing wireless technology of Telematics can also bring significant added value to self-driving cars. Telematics requires high-bandwidth, low-latency, reliable communication between the various sensors involved in or associated with traffic behavior, and 5G mobile networks can enable such connectivity for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications.
jotrin will discuss how the Third Generation Partnership Project (3GPP) intends to adopt 5G technology in Telematics applications and the significant advantages this solution has over existing dedicated short-range communications (DSRC) or other cellular Telematics (C-V2X) solutions. It is important to note that the word "cellular" in "Cellular Telematics" is misleading in that it does not refer to a cellular network such as 5G in this application, but rather to the underlying electronic technology in cellular radio that allows direct communication between the two parties.
Technological change is on the horizon
From a communications technology perspective, the future of Intelligent Transportation Systems (ITS) services is already widely accepted, a trend that will eventually lead to autonomous driving and the need for highly connected vehicles through advanced communications technologies such as 5G Telematics. After years of research and driven by academia and industry, mature 5G technologies are already in use, so 3GPP has drafted 5G Telematics standards starting from version 16 of the standard.
Next, let's start with the definition of Telematics. The so-called "Vehicle to Everything" (V2X) is "Vehicle to Everything". This technology is a two-way communication method that transmits information between a car or pure electric vehicle and any surrounding entities that may affect it. Until fully autonomous driving is achieved, connected vehicle applications can already have a significant impact on traffic safety and convenience. The technology can also help reduce traffic congestion, reduce the environmental impact of traffic, and make the vehicle more comfortable for the driver and passengers inside.
With 5G in conjunction with Telematics, vehicle and pedestrian safety will be better protected. When a vehicle on an emergency mission approaches or a pedestrian is crossing a crosswalk, other vehicles nearby will receive distance and direction information and alert the driver or intervene directly to take control. The timing of the traffic signal can be controlled or extended for safety reasons or in the event of an accident, making it easier for drivers to notice pedestrians and avoid their sudden appearance in the traffic flow. When a traffic accident occurs, nearby vehicles receive the location and distance of the accident. In addition, school buses can also alert nearby vehicles to drive carefully or stop to avoid students while in motion and when stopping to pick up or drop off students, providing further safety for students.
Cellular Telematics (C-V2X) is a component of Telematics that complements line-of-sight (LoS) sensors such as cameras, radar and LiDAR, which are critical to safe driving. In addition, cellular Telematics provides greater sensing coverage than line-of-sight sensors and establishes the foundation for vehicles to communicate with everything around them. 2014 saw the launch of 3GPP's standardization study for cellular Telematics in Release 14 of the standard, using LTE as the underlying technology. The specification was published in 2017.
Telematics involves multiple types of communications, including vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P) and vulnerable traffic participants such as cyclists, as well as vehicle-to-device (V2D) and, for electric vehicles, vehicle-to-grid (V2G), as shown in the figure.
Figure 1: The main types of communication in the Telematics: vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I), and vehicle-to-network (V2N). Safety messages transmitted by the Telematics are Cooperative Awareness Messages (CAM) and Distributed Environment Notification Messages (DENM) in Europe and Basic Safety Messages (BSM) in the US.
At the same time, the automotive industry is looking for viable ways to reduce the cost of On-Board Units (OBU) to support 5G Telematics while maintaining or minimizing price increases.
5G Meets Telematics
5G-enabled Telematics will be easier, faster and more reliable, and the differences between 5G and Telematics architecture can be summarized in two points.
1.5G uses the same cellular infrastructure as other radio mobile services, which means that the entire territory is divided into several cellular cells with large overlap areas and managed by a system of antennas called "base stations".
2.Telematics, like other wireless services, uses a more flexible architecture, with a system of small antenna devices called "hotspots", with a strong cooperative strategy to ensure the best possible quality of connectivity.
DSRC vs. C-V2X: Which is better or worse?
Today, there are two high-speed communication protocols developed to improve vehicle safety, DSRC and Cellular IoT, both of which feature very fast transmission speeds, high data exchange frequencies and low latency. Both operate in the 5.9 GHz band, use the same use cases and the same message sets (SAE J2735 and J2945), and both use digital signatures to ensure the security and trustworthiness of the message providers. signals emitted by other vehicles.
The two technologies use different wireless standards: DSRC uses WAVE IEEE (802.11p), while Cellular Telematics uses the same Long Term Evolution (LTE) technology as cell phones. The US FCC has allocated the 5.9GHz band to Wi-Fi and C-V2X in November 2020.
DSRC and cellular C-V2X are not interoperable with each other, and they also exhibit different characteristics in various aspects. while DSRC has a transmission distance of about 300m, cellular IoT has lower latency, transmits 20% to 30% longer than the former, and performs significantly better than DSRC in the presence of obstacles, thus cellular IoT's overall performance is significantly better than DSRC, but for critical security applications, the transmission distance and reliability of DSRC are still sufficient.
Cellular Telematics Side Link
The 3GPP Release 16 standard introduces side links in cellular Telematics through 5G NR, enabling new applications of cellular Telematics such as follow-the-vehicle driving, advanced driving, extended sensors, and remote driving. In critical driving scenarios, where emergency braking and collision avoidance are commonplace, low latency and high reliability must be strictly ensured in Telematics, and the minimum transmission latency of cellular Telematics is no more than 4ms, and can be even lower in specific implementations. Reliability is a difficult feature to quantify, but in each new version of the 3GPP standard, a number of performance and safety improvements have been added to improve reliability, and new versions of the standard will continue to improve safety and reliability.
When the Telematics network is deployed, vehicles will regularly communicate their status and movement via broadcast messages, which will then make up the majority of short-range communications, especially during the first phase of deployment.
In areas with very high traffic volumes, available channel resources may be saturated, leading to increased packet loss, which can pose a threat to the safety of drivers and passengers. In response, researchers need to study and develop congestion control algorithms to modify these parameters before certain conditions reach critical levels. However, instead of starting directly with a specific algorithm, they first compared the Wi-Fi standard approach (IEEE 802.11p) with the cellular standard approach (side-link LTE Telematics defined in the 3GPP version 14 standard as part of Cellular Telematics).
The Cellular Telematics communication technology was developed by 3GPP to enable direct communication between Vehicle User Equipment (VUE) via a side link (also called PC5 interface). The cellular Telematics side link is the first wireless system to introduce distance as a dimension in the physical layer, allowing for a uniform communication range between line-of-sight and non-line-of-sight devices in a widely varying radio environment.
Cellular Telematics, starting with the Release 14 standard, includes two communication modes: direct mode (PC5), which can be used for the most direct as well as the most latency-sensitive communications; and network mode (called Uu), which is the connection of user devices to the UMTS terrestrial radio access network for broadcast-based communication over the existing cellular network.
PC5 mode supports two modalities.
In Mode-3 (scheduling) mode, the side link resource allocation is performed under the supervision of the eNodeB and requires the cellular infrastructure to support radio resource management.
2.In the Mode-4 (autonomous) approach, the vehicle performs distributed resource allocation and interference disposal on its own, without involving the cellular infrastructure (and naturally can be used normally in areas without cellular network coverage).
Security and privacy issues in Telematics communication
LTE-based Telematics communications use high capacity, large cellular coverage and widely deployed infrastructure to support various vehicle communication services for security-related and non-security-related applications. 3GPP and technology organizations such as Qualcomm have developed roadmaps for 5G-based Telematics services.
Security, as defined by 3GPP, includes confidentiality, integrity, authenticity and resistance to replay attacks.
More research is needed in 5G vehicle networks to address new privacy and security challenges, including secure mobility management for autonomous group driving, reliable cooperative driving, and efficient and privacy-conscious sharing and processing of vehicle big data.
Among the possible solutions for automotive security and safety, the full adoption of dual-key cryptosystems is a viable option for any cyber attack.
Telematics applications rely on continuous, detailed location information, which can lead to privacy issues. For private cars, location traces will reveal the movements and activity trajectories of the driver, who may not necessarily be the owner of the vehicle. In short, sending and disseminating location information about connected car users can create privacy issues for both owners and drivers.
Many other Telematics applications involve communication between vehicles, can complement existing turn assist and emergency braking warnings, and can help provide a more complete picture of an intersection. By extending the concepts presented by Waze (a user community-driven navigation app), speed control or recommendations can be implemented to alleviate traffic congestion, as well as real-time updates on GPS maps for activities such as lane closures and road construction. Many of today's vehicles also support software updates via OTA, covering all types of software-driven systems from map updates, bug fixes, security updates, etc. This functionality must also rely on some form of Telematics.
Telematics safety messages can include Basic Safety Messages (BSM), as defined by U.S. standards, or Co-aware Messages (CAM) and Distributed Environment Notification Messages (DENM), as defined by European standards.
The BSM contains position, velocity and acceleration information and is transmitted up to 10 times per second. The messaging system also enables the vehicle receiving unit to predict collisions and warn the driver.
Telematics Message Protection and Security
V2X and V2I communications require strong security to protect messages from fraudulent or misleading use, which could otherwise lead to security and privacy issues. An alternative security approach is to sign messages using public key certificates, which are used to prevent unauthorized parties from interfering with data exchange and to securely anonymize communications.
A public key infrastructure (PKI) contains policies and processes for creating, managing, using, maintaining, and revoking digital security certificates that can be used to securely transmit electronic messages. PKI employs more stringent identity confirmation than authentication by password only.
5G NR Intent Sharing
Intent or trajectory sharing can enable further enhancements to autonomous driving by providing higher levels of predictability and traffic efficiency in advanced path planning.
5G NR will enable intent sharing through
High throughput: 5G can provide the required high data rates, such as higher than 100 Mbps over a 1 km range.
High reliability: 5G can ensure that trajectory information is shared accurately and in a timely manner.
Low latency: With 5G's low latency capability, trajectory information can be shared in milliseconds.
Cellular Telematics in Congested Highway Scenarios
The 5G Automotive Association (5GAA) tested the performance and functionality of connected vehicles in the V2X Functional and Performance Test Report, where cellular connected vehicle technology was tested in a highly congested scenario in a lab environment. Even in such a congested scenario, Cellular Telematics performed well with latency within the 100ms tolerance set for this scenario. In a series of laboratory and field tests, the researchers found that Cellular Telematics communication on 20MHz CH183 has the same reliability (packet reception rate vs. distance) as the same BSM-like messages on 10MHz CH184. Under line-of-sight (LoS) conditions up to 1.4 km, high-load cellular Telematics transmissions on CH183 have negligible impact on DSRC basic secure transmissions on CH172.
Under LoS conditions within 1.4 km, the impact of high-load cellular Telematics transmissions on CH183 on V2I and I2V transmissions on CH178 is negligible.
Under LoS conditions within 1 km, the high load cellular vehicular network transmission on CH183 has negligible impact on V2I and I2V transmission on CH180.
In support of the 5GAA's new waiver request to the Federal Communications Commission (FCC) for Cellular Telematics deployments, both Ford and Qualcomm have conducted additional field tests demonstrating that Cellular Telematics can achieve fully acceptable performance, particularly under LoS conditions.
According to the 5GAA website, Cellular Telematics is ready for deployment on commercial chipsets and could begin in-vehicle deployments worldwide during 2020 or 2021. They will work with relevant standards development organizations (SDOs) to drive the demand for 5G Telematics to the ground to create a successful Telematics ecosystem.
The FCC has completely transformed the U.S. market for collaborative intelligent transportation systems (C-ITS) for vehicular communications through its alignment of the 5.9 GHz band.
The automotive industry must forge ahead in a narrow spectrum, thus requiring the adoption of cellular Telematics technology rather than the already widely used Dedicated Short Range Communications (DSRC) technology. This change paves the way for the development of Telematics and removes the uncertainty associated with competing technologies.
Telematics and 5G are rapidly becoming indispensable technologies for automakers as the technology works to make fully autonomous vehicle technology commercially available in the coming years. Ford will launch cellular connected car vehicles in China in 2021 and expects to bring the technology to all of its vehicles sold in the U.S. starting in 2022. 5GAA will work with relevant SDOs to drive demand for 5G connected cars to the ground, thereby creating a successful connected car ecosystem.
Financial services firm IHS Markit published an analysis of 5G, cellular Telematics and connected cars in 2021 on its website in January 2021.
According to a news release from Market Watch on the C-V2X study.
"The V2I communication segment is expected to grow at a CAGR of over 12% during the forecast period as smart transportation infrastructure is gaining adoption. Intelligent transportation infrastructure involves smart traffic signals and smart surveillance cameras that communicate with vehicles to provide information about traffic and road conditions."
There are many more exciting new automotive technologies on the way that will serve to dramatically change the way we drive our cars and make driving a better thing.