Internet speeds are the one thing we all struggle with. Whether downloading urgent work files, completing your tech project, browsing or Netflixing, low internet speeds often play the spoilsport. The demand for a faster data transmission network has been a constant from the time of the internet. This demand has laid the foundation for 5G, the next generation of communications technology. Although 5G is still in its preliminary stage, the entire industry is working together to determine its final form.
Challenges in Designing the Next Generation Network
As the number of mobile users and their expectations rise, 5G must be capable of transmitting more data quicker than existing mobile network base stations.
To achieve this, wireless communication engineers must design a set of entirely new technologies. These technologies will allow the latency of 5G data transmission to be less than one millisecond (compared to the about 70-millisecond latency of existing 4G networks) and achieve a peak data download speed of 20 Gbit/s (compared to 1 Gbit/s for 4G).
It is still unclear what technologies will play the crucial role in the development of 5G over the long term, but there are already some early contenders. These technologies include millimeter waves, small base stations, massive MIMO, full duplex, and beamforming.
Today's wireless networks face one critical challenge: the increasing number of users and devices are consuming more data than ever before. Still, the telecom carriers have to restrict them to the same radio spectrum frequency band that they have always used. This means that each user is allocated a limited amount of bandwidth, leading to slower speeds and frequent disconnections.
As the number of devices connected to wireless networks increases, the shortage of frequency band resources will become even more prominent. We continue to share the limited bandwidth of an extremely narrow spectrum. This has a major impact on user experience. However, millimeter wave technology offers a practical solution to this problem.
What Is Millimeter Wave?
Millimeter waves, also known as extremely high frequency (EHF), is a band of radio frequencies that is well suited for 5G networks. Compared to the frequencies below 5 GHz previously used by mobile devices, millimeter wave technology allows transmission on frequencies between 30 GHz and 300 GHz. These frequencies are called millimeter waves because they have wavelengths between 1 mm and 10 mm, while the wavelengths of the radio waves currently used by smartphones are mostly several dozen centimeters.
So far, only radar systems and satellites use millimeter waves. However, now some mobile network providers have also started using millimeter waves (for example, to transmit data between two fixed points, such as base stations). Nonetheless, the use of millimeter wave frequencies to connect mobile users to nearby base stations is an entirely new approach.
What Are the Advantages of Millimeter Wave Technology?
There are two ways to increase the speed of wireless data transmission: increase the spectrum utilization, or increase the spectrum bandwidth. Compared to the first approach, increasing the spectrum bandwidth is simpler and more direct. Without changing the spectrum utilization, increasing the available bandwidth several times over can increase data transmission speeds by a similar amount. The problem is that the commonly used frequencies below 5 GHz are already extremely crowded, so where can we find new spectrum resources? 5G's use of millimeter waves uses the second of the two methods to increase transmission speeds.
Based on communication principles, the maximum signal bandwidth in wireless communication is about 5% of the carrier frequency. Therefore, the higher the carrier frequency, the greater the signal bandwidth. That’s why, among the millimeter-wave frequencies, 28 GHz and 60 GHz are the most promising frequencies for 5G. The 28 GHz band can provide an available spectrum bandwidth of up to 1 GHz, while each channel in the 60 GHz band can provide an available signal bandwidth of 2 GHz (a total available spectrum of 9 GHz divided between four channels).
Comparatively, the maximum carrier frequency of the 4G-LTE band, 2 GHz, provides an available spectrum bandwidth of only 100 MHz. Therefore, using millimeter wave frequencies can easily increase the spectrum bandwidth by a factor of 10, allowing for a massive increase in transmission speeds.
What Are the Disadvantages of Millimeter Wave Technology?
The use of millimeter waves has one major drawback. Millimeter waves are not capable of penetrating structures and other obstacles. Even leaves or rain can absorb these signals. This is also why 5G networks will have to adopt the small base station method to enhance traditional cell tower infrastructure.
Because millimeter waves have high frequencies and short wavelengths, the antennas used to receive them can be smaller, allowing for the construction of small base stations. We can predict that, in the future, 5G mobile communication will no longer depend on the construction of large-scale base stations, but rather many small base stations. This will allow 5G to cover peripheral areas not reached by large base stations.
Silicon Talks author Li Yirei said that the present 5G band plans adopted by major carriers use more traditional frequencies below 6 GHz to ensure signal coverage in open spaces, and use micro base stations with millimeter wave technology to provide ultra-fast data transmission indoors.
Using millimeter waves and other 5G technology, engineers hope that 5G networks will not only serve smartphone users, but also play a critical role in self-driving cars, VR, IoT, and other fields.
Researchers and companies already have high hopes for 5G, promising consumers that it will provide ultra-low latency and unprecedented data speeds. If they can overcome the remaining challenges and find a clear way to allow cooperation throughout the entire ecosystem, we can expect to see the commercial deployment of 5G services within the next five years.
We have discussed several aspects of millimeter waves, and how these waves offer a practical approach to solving the mobile bandwidth crunch. The technology is likely to gain wide-spread adoption soon.
(This is a slightly modified version of an article originally published in Alibaba Cloud. The original article can be found at https://www.alibabacloud.com/blog/understanding-how-millimeter-waves-power-the-5g-network_593839)