Wu hequan, an academician of the Chinese academy of engineering, delivered a speech at the autonomous driving sub-forum of the 2020 China association of 100 forum on electric vehicles, saying that although 5G communication technology brings possibilities for Internet of vehicles and autonomous driving, there are still many challenges to meet the demands of Internet of vehicles and autonomous driving.
Internet of vehicles and L5 level autonomous driving require 5G
According to wu, different levels of autonomous driving have different requirements for time delay and require different technologies to support it. "In terms of communications technology, L1 and L2 support should be fine in the 4G era, but if you really want to go to L5, you need 5G."
Car networking communication mode can be divided into four categories, respectively is V2V (the communication between the car and car), V2P (communication) between cars and pedestrians, V2I (cars and roadside communication, cloud, traffic lights, parking lot, control signal transformation) and V2N (car and network communication, solve the problem of optimization of traffic flow, make traffic planning).
Remote driving and autonomous driving require an end-to-end delay of no more than 5 milliseconds, a reliability of 99.999%, and 1GB of data per second per vehicle. In accordance with the eV2X (enhanced v2x communication) requirements of the organization for standardization of mobile communications 3GPP, the delay should not be higher than 3 ms in autopilot and sensor sharing, which requires 1GB of bandwidth. In the 4G era, the LTE delay is about 100 milliseconds, which can be reduced to 10 milliseconds by using edge computing, but still beyond the current requirements for autonomous driving. "so we need to have 5G+ edge computing, so to speak, the Internet of vehicles needs 5G, only 5G can support this requirement." "Said wu hequan.
At the same time, compared with 4G, 5G has 1-2 orders of magnitude improvement in performance. 5G's features of enhanced mobile broadband, high reliability, low latency and wide coverage and large links are exactly what the Internet of vehicles needs.
5G still faces many challenges in meeting the needs of the Internet of vehicles
Although 5G is a necessary condition for autonomous driving and Internet of vehicles, it still faces many challenges to fully meet the requirements of Internet of vehicles. 5G was first designed for public communication, which is 80% indoor and non-mobile. More than 80% of the Internet of vehicles is in the driving state, which requires higher mobility management. In addition, public communication occupies the channel only when it is used, mainly point-to-point communication; The Internet of vehicles is basically always online, and the communication is point-to-point and point-to-point. Whether the network slice of 5G era can be accurate and meticulous enough is a problem.
Wu hequan further pointed out that traditional operators mainly use TDD mode for 5G, with asymmetrical upstream and downstream design. Most consumers download more from the Internet, but upload less by themselves. Therefore, the same frequency band is generally arranged as "three-quarter split", with 30% time slot for uploading and 70% time slot for downloading. However, the Internet of vehicles is more about sensor data report, while the download is less, so it should be "inverted split". If the two different upstream and downstream time gap ratio is installed on the network of the same operator, it will interfere with each other. "To build a support network of 5 G private network requires special frequency, the current between the frequency of car networking is 5.8 G, bandwidth is not higher than 75 million, really for V2V only 25 million, so if every car should have a dedicated radio frequency, frequency is not enough, so the frequency for car networking is a challenge, and the construction of a special city car networking 5 G private network also has a cost challenge."
And the age of 5 g car networking still exist between each problem, group support problem, and increased risk of security problems, operational support is also very complex, 5 g with virtual NFV unit (network virtualization), and network section, all of these are dynamic, must carry on the dynamic management, a real time for 5 g or so for car networking, is a big challenge.
In the end, wu hequan concluded, "although 5G is closer to the needs of the Internet of vehicles than other mobile communication systems, some features of the actual Internet of vehicles are different from those of public communication faced by 5G. Moreover, there are many new demands, and the existing 5G technology may not be able to adapt. In my opinion, 5G Internet is not easy to say love you. Cars are always on the way, and so is 5G's Internet innovation!"