The arrival of 5G is getting closer and closer. "Wi-Fi will die" is not an exaggeration

Recently, the foreign research organization OpenSignal conducted a study and comparison of Wi-Fi download speeds and mobile network download speeds around the world and found that the average mobile network download speeds in 33 countries, including Australia, Germany, Greece, and Myanmar, exceeded the local Wi-Fi download speeds. Based on this, some people even made the judgment that "Wi-Fi is dying."

So, in an era where mobile Internet speeds continue to break records, where is Wi-Fi going?

[[252892]]

“Wi-Fi is dying” is not an exaggeration

Wi-Fi is essentially an alternative wireless Internet access solution. When mobile network charges are too high and access is difficult, Wi-Fi converts wired optical cable signals into wireless signals, improving access convenience while reducing access costs, providing users with an ideal wireless access solution.

"With the implementation of 5G applications and the reduction of corresponding tariffs, these advantages of Wi-Fi will be weakened. To some extent, the judgment that 'Wi-Fi will die' is not alarmist," said Zhao Zhenying, a researcher at the National Engineering Laboratory for E-Commerce Transaction Technology and an Internet of Things observer.

In an interview with Science and Technology Daily, Xiang Ligang, CEO of the communication portal Feixiang.com, said that whether Wi-Fi will be replaced depends on the application scenario. "Public Wi-Fi may be replaced, but home Wi-Fi currently does not seem to be replaced," Xiang Ligang said.

Because public Wi-Fi is slow and unstable. "In public places, dozens of people usually connect to the same router, which inevitably leads to slow Internet speeds due to too many connected devices. In addition, wireless network coverage is limited and does not support continuous use. Its signal strength will weaken as the distance between the device and the node increases." Xiang Ligang said, for example, Wi-Fi technology itself has a transmission speed of 11MB/s, but as the distance increases, the speed of the user terminal is only 1MB/s. At the same time, wireless signals are easily interfered by buildings.

At airports or train stations, users generally do not stay in the same place for a long time and are likely to move frequently. If the moving distance is too long, the device in the user's hand is likely to be disconnected from one router first and then reconnected to another router. "If it is in a mobile network environment, users do not have to switch between different routers and are always connected to the Internet." Xiang Ligang said that there are a large number of users in public places, and the speed of Wi-Fi Internet access rarely exceeds 10MB/s, but 4G theoretically has a maximum speed of 300MB/s, and at least 20MB/s-30MB/s is guaranteed. Coupled with the reduction in traffic fees, with the advent of the 5G era, there is a high possibility that Wi-Fi in public places will be replaced.

"But at present, I don't see any signs of Wi-Fi being replaced at home or in the office." Xiang Ligang said that the range of users' mobility at home and in the office is relatively fixed, and the number of people using the same router is not as large as in other places, so the speed of using Wi-Fi to surf the Internet is more guaranteed. From a practical point of view, it is unlikely that home computers, TVs, and tablets will all be connected to the mobile network.

Zhao Zhenying believes that this is not a competition between Wi-Fi and mobile networks, but a competition between wired networks and wireless networks. "Wi-Fi is nothing more than a signal conversion. When the speed of mobile networks is fast enough, there is no need to convert wired network signals into wireless signals. Therefore, Wi-Fi has no value to exist." Zhao Zhenying said that this is just like when mobile phones have SMS functions, pagers have no value to exist and quickly die out.

Mobile networks have more advantages in spectrum resources

What determines the speed of the Internet? First of all, we need to mention the concept of "spectrum". Spectrum resources are the lifeblood of mobile communications, and the spectrum range basically determines the characteristics of a wireless technology.

"Spectrum is to communications as land is to real estate. Without land, you cannot build a house, and without spectrum, communication transmission cannot be achieved." Xiang Ligang said that spectrum resources are the carrier for transmitting information through wireless communications and are the basic resources required for mobile communication systems.

Xiang Ligang said that there are good and bad lands, and similarly there are good and bad spectrums. Low-frequency spectrum has stronger penetration and longer transmission distance. However, spectrum resources are limited, and good land is often obtained by the first come, first served. Unlike most countries, my country adopts allocation rather than auctioning to supply spectrum, and high-quality spectrum resources have been allocated to the military, scientific research institutes, radio and television stations and other institutions early on.

"In the past, mobile communication resources mainly served telephone services and did not involve Internet services. And making phone calls does not require a lot of spectrum, so the spectrum available for mobile communications is very small." Xiang Ligang said that this led to relatively poor spectrum resources in mobile communication networks.

If good land is already allocated in advance, we need to find ways to maximize the use of existing land. "With the update of technology, the utilization rate of mobile communication spectrum resources is constantly improving, and network deployment capabilities are also gradually increasing," said Xiang Ligang.

Cellular technology for mobile communications is a way to "improve land utilization." The cellular mobile communication system is composed of a mobile service exchange center, base station equipment, mobile stations (user equipment), and transmission lines from the exchange center to the base station. Xiang Ligang said that cellular technology has advantages such as good service performance, high spectrum utilization, compact user terminals, and low radiation. "When using the mobile network for communication, the mobile device connects to the next base station and then cuts off the connection with the previous base station. This soft switching can ensure that users can use the network smoothly." Xiang Ligang said, but Wi-Fi technology does not have such a mechanism.

Wi-Fi technology, which started in 1999, has used two frequency bands since its inception, one is 2.4GHz and the other is 5GHz, with 2.4GHz being the main frequency band. However, the bandwidth of the 2.4GHz band is less than 100MHz, and the bandwidth limitation makes it difficult to increase the transmission rate. The other frequency band, 5GHz, is idle due to poor diffraction and penetration capabilities and high deployment costs.

Latecomers should focus on safety

The essence of Wi-Fi is to convert wired network signals into radio waves for networking, and common routers are used to achieve this conversion. Mobile networks are directly connected to base stations, which are then connected to wired networks. From a technical perspective, mobile networks have more advantages than Wi-Fi in terms of security.

Zhao Zhenying said that the theoretical transmission rate of 5G can reach 10GB/s. At present, the three major domestic operators have announced the timetable for the construction of 5G networks, and it is basically no problem to realize commercial use by 2019. "In theory, the mobile network speed has basically surpassed Wi-Fi, and the actual application will also begin in 2019." Zhao Zhenying said.

"The development of mobile networks has gone through an evolutionary process from analog to digital, from 2G, 3G to 4G, and 5G. In this process, Wi-Fi is just an alternative solution to solve the problems of mobile networks being immobile, slow access speeds, and high fees compared to fixed networks." Zhao Zhenying emphasized that if these three problems with mobile networks can be solved, the corresponding alternative solutions will have accomplished their mission. So it is not that mobile networks have replaced Wi-Fi, but that mobile networks have solved their own problems, making the Wi-Fi "patch" worthless.

Zhao Zhenying believes that after 5G is fully commercialized, users' demand for high-quality network speed will be basically met. "If new technologies emerge, I think they should develop in a safer direction, such as quantum transmission," Zhao Zhenying said.

Mobile networks are accelerating their iteration, and traditional network access technologies are also incubating a "revolution", trying more ways to expand spectrum resources. Previously, some researchers proposed using green and energy-saving LED lights as a communication method for transmission base stations, which people call visible light communication (VLC for short).

Visible light communication refers to a technical means of transmitting information using high-speed light signals emitted by fluorescent lamps or light-emitting diodes. Compared with radio communication, visible light communication has opened up new spectrum resources. It has extremely high transmission rate, security and privacy, no electromagnetic interference and radiation, and no need for frequency band license authorization. With the help of LED lights, high-speed wireless communication can be achieved at low cost. "When the light is turned on, it is Wi-Fi, but light does not have the ability to diffract and penetrate. This means that you can surf the Internet facing the light bulb, but you will be disconnected as soon as you turn around." Xiang Ligang said that perhaps in the future, it can be improved using reflection and other technologies.

"On the whole, Wi-Fi has the characteristics of flexible networking. In specific areas, especially indoor local environments, there is no real solution to replace it, so Wi-Fi will continue to exist in the short term." Xiang Ligang said, but it is undeniable that Wi-Fi technology is being marginalized due to its many disadvantages such as security risks, high power consumption, small coverage area and poor network stability.