What is V2X?

What exactly is the Internet of Vehicles? As one of the three most important spaces for human activities, along with home space and work space, the importance of the Internet of Vehicles is also increasing.

What is the Internet of Vehicles?

The Internet of Vehicles includes V2V, V2I, V2P, V2N and V2X. What do these letters mean? V stands for Vehicle, which represents the car itself; 2 stands for to, which is often used in English abbreviations, such as B2B/B2C, etc.; the following letters are the objects to which the car needs to transmit information.

V2V stands for Vehicle to Vehicle, which means wireless communication between vehicles. In this way, a car can sense information from surrounding cars while driving, prevent risks in advance, and notify the driver to take evasive measures. This function is used in many household cars now, mainly using millimeter-wave radar or cameras to detect safety risks.

V2I, where I stands for Infrastructure, refers to the communication between vehicles and road infrastructure, such as traffic lights, cameras and other detection equipment, as well as traffic signs such as lane markers. With this function, you no longer have to worry about crossing the line or running a red light. It can also reduce the probability of traffic accidents when visibility is poor and improve driving safety. The red light countdown function displayed on Amap is also a type of V2I.

V2P, where P stands for Person, refers to the communication between people and cars. When we sit in the car, the communication between people and cars begins. The speed displayed on the meter, the amount of gasoline, and the door alarm, etc., all involve the exchange of information between people and cars. This kind of communication between people and cars is also crucial. As a friend said, after getting in the car, his legs are the accelerator and brake, his hands are the steering wheel, and he always keeps his eyes and ears open. In addition to the communication between the car and the driver, it also includes the communication between the car and pedestrians on the road. How can the car predict the direction of pedestrians and take necessary safety measures? This is also a very important topic for road traffic safety.

V2N, the N here stands for Network, which means that vehicles can be connected to the data center or control center, and the vehicle can be controlled through the control center.

Obviously, these cannot cover all vehicle communications, so there is V2X, where X stands for Everything, and the concept of vehicle-to-everything communication comes out, that is, the communication between the vehicle and all matters, including V2V, V2I, V2P and V2N, etc. Through the implementation of V2X technology, the safety of manual driving and autonomous driving can be achieved.

What are the standards for the Internet of Vehicles?

At present, there are two main communication standards for V2X: DSRC and C-V2X. DSRC is a short-range wireless communication system based on the 802.11p standard of the IEEE802.11 family, while C-V2X is a vehicle networking system based on cellular communication networks, from the early LTE-V2X to the current 5G-V2X.

DSRC, the acronym is hard to tell, but the full name is actually quite simple. Dedicated Short-Range Communications. DSRC is a wireless communication technology based on 802.11p that enables highly secure, high-speed direct communication between vehicles and surrounding infrastructure without involving any cellular infrastructure. IEEE 802.11p is an amendment to the IEEE 802.11 standard that defines enhancements to support Intelligent Transportation System (ITS) applications.

DSRC operates in the 5.9 GHz (5.85-5.925 GHz) frequency band, which includes 7 10 MHz channels and a 5 MHz guard interval reserved at the bottom, and specifies whether each channel is a service channel (Service Channel, SCH) or a control channel (Control Channel, CCH).

Chip manufacturer NXP has high hopes for DSRC technology and is also a strong promoter. In 2018, NXP launched a white paper on DSRC technology - IEEE802.11p ahead of LTE-V2V for safety applications - White Paper. It made a detailed comparison between 802.11p and LTE-V2V technologies and launched a series of chips for DSRC short-distance communication.

The V2X system platform launched by NXP operates in the 5.9 GHz and 760 MHz frequency bands and is compatible with global software protocols from all leading suppliers, enabling a truly global V2X solution. The platform complies with and exceeds the current guidelines of the U.S. Department of Transportation's proposed rulemaking notice, as well as emerging standards in Europe, Japan, and South Korea. It is currently used in many cars including Volkswagen.

DSRC is a short-range wireless communication with low latency and high-speed communication, and does not require connection to a cellular network. However, the performance of DSRC, which is based on Wi-Fi technology, has limitations. Wi-Fi is difficult to support high-speed mobile scenarios. Once the mobile speed increases, the DSRC signal begins to drop sharply, the reliability is poor, and the delay jitter is large. Therefore, for a long time, the performance of DSRC has been unstable and has been in the testing stage.

Therefore, C-V2X was developed. C stands for Cellular, and C-V2X is the Internet of Vehicles based on cellular communication.

In fact, when 802.11p was positioned as the DSRC standard in 2010, 3GPP was also discussing C-V2X, a cellular communication standard for connected vehicles. However, in the 3G era, due to the speed and latency issues of cellular communication, it was difficult to apply it to connected vehicles. Therefore, it was not until the 4G LTE era that the cellular communication standard based on LTE-V2X was included in 3GPP's Rel-4. Therefore, C-V2X mainly includes the previous LTE-V2X and the current 5G/NR-V2X.

Qualcomm, a strong supporter of C-V2X, launched the 9150 C-V2X chipset as soon as the LTE-V2X standard was launched. The 9150 chipset is fully optimized for the Rel-14 version of C-V2X direct communication. This version not only supports GPS positioning, but also Beidou positioning and high-precision positioning.

Data shows that the world's leading automakers and suppliers are using Qualcomm's 9150 C-V2X chipset solution to accelerate the commercialization of C-V2X technology. Obviously, V2X based on 5G NR has more advantages, with ultra-low latency, ultra-high throughput, and ultra-high reliability, which provides guarantees for autonomous driving. Therefore, it has also received support from more manufacturers. Qualcomm's report details the development of the 5GAA organization, including most well-known automakers, communication operators, and communication equipment manufacturers, among which Huawei is also an active promoter of C-V2X technology.

According to Huawei's official website, Huawei and 28 related partners including China Mobile, the Traffic Science Institute of the Ministry of Public Security, China Academy of Information and Communications Technology, FAW Group, SAIC Group, and Audi China have deployed a city-level C-V2X network in Wuxi. The Wuxi project covers a total of 170 square kilometers of main roads in the urban area, including 240 intersections, and has developed 12,000 ordinary Internet of Vehicles users. Huawei and related partners have deployed roadside units RSU on a large scale on open roads in Wuxi. This is the first time in the industry to deploy a C-V2X commercial solution in the world. RSU connects a variety of road traffic elements such as traffic lights, cameras, signs, speed limit signs, front/rear terminals, etc., and cooperates with Huawei T-Box to achieve vehicle-road collaboration based on the PC5 interface. Huawei deployed a city-level C-V2X network in Wuxi, using RSU (Road Side Unit) and T-Box based on self-developed chips. It is the world's first large-scale deployment of end-to-end commercial solutions, realizing the application of C-V2X in multiple scenarios.