In the 30 years between the development of mobile communications, millimeter wave has been an uncultivated wild land, such as Qualcomm, Ericsson, Huawei, ZTE and other communications giants are its ongoing laboratory research, now lives in the millimeter wave the application has been more and more, millimeter-wave radar technology, 5G technology in both millimeter wave figure. For the millimeter wave action as well as its advantages and disadvantages, you know how much? Quickly learn about it!
First, what is the millimeter wave
Millimeter Wave really is what? In fact, we can clearly looking through the high school physics textbooks, which essentially is a kind of high-frequency electromagnetic wave, which is 1-10 mm wavelength electromagnetic waves, in general, is the frequency of between 30GHz-300GHz electromagnetic waves. 5G band is one of the main communication used.
Second, the advantages and disadvantages of millimeter wave
1, millimeter wave advantages:
1) extremely wide bandwidth. Generally considered millimeter wave frequency range of 26.5 ~ 300GHz, bandwidth of up to 273.5GHz. Over the full bandwidth from DC to the microwave 10 times. Even considering atmospheric absorption, use of only four main windows propagates in the air, but also the total bandwidth of up to four windows 135GHz, microwave or less 5 times and bandwidth of each band. With a variety of multiple access multiplexing technique can greatly enhance the use of channel capacity for high-speed multimedia transmission services, which undoubtedly attractive in a tight frequency resources today.
2) narrow beam. Narrow beam of millimeter-wave beam at the same size than the microwave antenna much. For example a 12cm antenna, when the beam width of 18 degrees 9.4GHz, 94GHz and a beam width of only 1.8 degrees. It can be resolved spaced closer or smaller target more clearly observe details of the object.
3) High reliability, higher frequency interference so little rain can better resist the effects of weather, to provide a stable transmission channel; compared with a laser, the millimeter waves propagated by the climate much smaller, It can be considered all-weather properties.
4) good direction, the millimeter wave in the air by absorbing a large variety of suspended particles, such that the transmission beam is narrow, increasing the difficulty of eavesdropping, for short-range ad-hoc communication;
5) a very short wavelength, a desired antenna size small, easy to integrate large-scale antenna array in a small space. And microwave compared to the size of millimeter wave component is much smaller. Therefore millimeter-wave systems more easily miniaturized.
2, millimeter wave drawbacks:
1) atmospheric propagation attenuation serious.
2) high precision machining device.
At the beginning we have been clear, is part of millimeter wave (more dry v: hongsong2019) 5G communication is one of two major bands of 5G communication, it brings more than 5G network speed is very fast, it is an important part of 5G differentiated experience.
The highest millimeter wave, perhaps is not taken seriously as a 5G 5G technology in difficulty at the beginning, but the lack of a millimeter-wave 5G, is undoubtedly a soulless 5G.
Q & A on the millimeter wave
Q: At present, the millimeter wave in the domestic scenario What?
A: millimeter wave scenarios: eMBB, WTTx, mobile backhaul.
Q: advantages and disadvantages of the main operators the choice of frequency bands which can speak at the actual thing??
A: sub3G coverage and good performance advantages, disadvantages less available resources, rich in C-band resources advantages, disadvantages uplink and downlink imbalance.
Q: Why are the millimeter wave tdd?
A: The high bandwidth of the millimeter-wave, because of cost considerations, UE does not need to support too much bandwidth, the higher bandwidth requirements of the FDD band phone support, and easier to apply TDD beam-forming.
Q: sub 3g coverage 4G 5G and do the same?
A: sub3g of 4G and 5G covering almost, because no matter what the technology, sub 3g bands are the same, the effect is almost covered.
Q: AAU power than how RRU power?
A: AAU power higher than the RRU, the current 200W, 240W, 320W them.
Q: Now that all up and down the decoupling manufacturers Huawei support it or support??
A: The up and down the decoupling of the agreement, and the manufacturer has nothing to do, some manufacturers currently supported, and some manufacturers are not supported.
Q: What is the mainstream of the 5G band?
A: The current mainstream 5G band mobile 2.6G, Telecom and China Unicom share 3.4-3.6G.
