The advantage of 5G: not speed, but low latency

Many people say that 5G is not equal to 4G+1G, but when demonstrating 5G, they often only show the peak rate, habitually returning to the logic of 4G+1G. In fact, the real trump card of 5G may not be high rate. If 5G is really a new energy source, "speed" is definitely not the key to enter all walks of life, "low latency" is the key.

19ms gap

What is the difference between 5G and 4G? Many people may blurt out that the change is the improvement of network speed. Even in many news reports, 5G technology was demonstrated in a certain place on a certain day of a certain month of a certain year. It only takes X seconds to download a high-definition movie on a mobile phone. However, the most qualitative change between 5G and 4G is not the high speed, but the low latency. In this regard, Ericsson and Paris Saint-Germain Football Club have done such a test.

The test is conducted using 4G VR devices and 5G VR devices respectively. When the athletes put on the VR devices, they will exercise through the first-person perspective images displayed by the VR devices instead of their eyes.

The latency under 4G network is 20ms. When a group of players are practicing shooting, although the goalkeeper can see the video normally, he is unable to save the flying football.

The latency of the 5G network is 1ms. When doing the same shooting exercise, the goalkeeper can not only see the video, but also see the picture in near real time, so he can catch the ball calmly. The goalkeeper even said that it is "easy" to guard the goal with 5G VR.

In addition, Ericsson also let the players of Paris Saint-Germain try to juggle the ball while wearing 4G VR equipment and 5G VR equipment respectively. The 5G VR screen with a delay of only 1ms allowed the players to successfully juggle the ball. However, under the 4G network, it is this 19ms gap that prevents even high-level athletes from completing the most basic juggling action, and even from completing the return pass of the incoming ball.

Low latency stimulates new gaming opportunities

From the above comparison, it is not difficult to conclude that low latency is the real trump card of 5G, or in other words, 5G upgrades the low latency of the original 4G network to almost no latency. In fact, taking many online games as an example, the more real-time confrontation features, the more developers need to work hard on latency optimization. For example, Nintendo specifically optimized the online battle of the console game "ARMS" to solve the delay between the two boxers during the fight. For many mobile games, such as football, where latency is related to the timing of shooting, in the current 4G network environment, there are not even online competitive products that can satisfy players.

At the same time, cloud gaming has also become popular. A large number of companies such as Google, AT&T, Verizon, Nvidia, and Tencent have all made arrangements in this area to varying degrees. Judging from the demonstration results, whether it is on a laptop, tablet or mobile phone, the game can run the same as a local game console, and low latency naturally plays an important role in this.

On the other hand, the VR devices used in the above tests will undoubtedly bring new opportunities to VR games. VR will further move between virtuality and reality. The ultra-low latency will make VR games more competitive during battles, and even real physical contact and confrontation can be added, giving developers more design space.

Low latency is a matter of life and death

Another important significance of low latency is that if the 19ms difference between 4G and 5G only affects the victory or defeat of players in games, then it directly affects life safety in autonomous driving, smart factories, and remote surgery with robotic arms. Just like the case above, if the goalkeeper who can normally catch the ball is compared to a car, then it is very likely that the car will be delayed in avoiding the target due to the 19ms delay, thus causing a traffic accident. The same reasoning applies to factory operations that require refinement, whether the final product is qualified, and whether it will cause production accidents; in the process of remote medical surgery, a hesitation may also cause operational deviations and medical accidents.

▲ Latency sensitivity and data rate requirements vary by 5G use case

From the chart "Latency sensitivity and data rate requirements vary by 5G use case" provided by Forrester in the report "IoT Use Case Requirements Will Meet Your 5G Needs", in the commercial applications of 5G, in addition to the medical field which has high requirements for both rate and latency, in fields such as autonomous driving, factory automation, and remote control, the requirement for latency is actually higher than rate. Low latency is the key to whether the above applications can be truly implemented.

However, as of now, 5G's real trump card, low latency, has not officially entered the stage of adding vitality to all walks of life. Since the 5G network is still in the R15 stage, global operators are still focusing their business on the eMBB scenario. However, attempts to provide related low-latency services in the R16 stage have already begun. For example, China Mobile, Huawei, and the General Hospital of the People's Liberation Army have completed the country's first 5G-based remote Parkinson's disease "brain pacemaker" implantation surgery; China Telecom has completed the core installation of the 5G communication system in the smart factory of Changxing Noli Intelligent Equipment Co., Ltd.; South Korea has also recently announced plans to establish the world's first 5G-based autonomous driving test field in Seoul.

Perhaps in 2020, 5G’s real trump card, “low latency”, will be unveiled more, and then every practitioner’s slogan of “5G is like electricity, leading a new round of industrial revolution” will come true.