Radio waves are electromagnetic waves in the radio frequency band that propagate in free space (including air and vacuum). The modes of transmission are direct, reflection, refraction, penetration, bypassing (diffraction) and scattering. The shorter the wavelength of radio waves, the higher the frequency, the more information transmitted in the same time, on the contrary, the lower the frequency, the smaller the propagation loss, the farther the coverage distance, and the stronger the bypassing ability. However, the frequency resources of low frequency band are tight and the system capacity is limited, so the radio waves of low frequency band are mainly used in radio, TV, paging and other systems. 

The characteristics of radio waves 

1, the characteristics of long wave propagation: long wave propagation is more stable 

2, the characteristics of medium wave propagation: medium wave can be propagated in the form of surface waves or sky waves, wavelength in 3000-2000 meters of radio communication, with wireless or surface wave propagation, the received field strength are very stable, available to complete reliable communication. 

3. Characteristics of shortwave propagation: Shortwave can be propagated by surface and sky waves, and the ground absorption is strong. 

4. The characteristics of ultra-short wave and microwave propagation: ultra-short wave, microwave frequency is very high, surface wave attenuation is very large, ultra-short wave, microwave generally do not use surface waves, sky wave propagation, only space waves. 

People who have understood the background knowledge related to wireless communication technology should have heard of the concept of Shannon's limit, which simply means that the higher the data transmission rate of a single channel, the more noise generated, the smaller the probability of correct transmission, eventually reaching the point where coding algorithms are unable to correct errors, thus becoming ineffective transmission. This phenomenon, similar to entropy increase, cannot be avoided, and better coding can only reduce the loss, and the marginal effect will become more and more obvious with improvement. 

This law determines that there is a limit to the bandwidth that can be achieved in a given frequency band, and the best way to really improve the overall carrying capacity is to broaden the available spectrum. Within the 14 radio bands defined by the International Telecommunication Union, the bands used for communication are mainly located between long wave (kHz class) and millimeter wave (100 GHz class), and applications from many different fields define their own bands within this range. We are familiar with the cell phone signal and Wi-Fi are within it, for example, the band used by 5G Sub6 is between 3GHz and 6GHz, while the band of Wi-Fi is concentrated in 2.4GHz and 5.8GHz. 

At the end of the 19th century, after nearly a century of concentrated exploration around electricity, electromagnetic waves were discovered by human beings, and in the following century, as the pioneer technology of wireless information communication, they shone in the military field of intelligence encryption transmission, to the civilian field of radio and television applications, making indelible contributions to the course of human history. 

With the passage of 2000, the miniaturization of communication equipment and mass has become the next direction of development of wireless communication, to today, wireless communication technology has changed five generations, people's hands of the big brother has also become a slim shape and full-featured smart phones, in this process, we also use the radio spectrum scale of the exponential expansion of the speed not imagined by the previous people. 

After experiencing the evolution from 2G to 4G, we actually expect wireless technology to continue to deeply change the form of production, life, entertainment and work, not just as a simple means of communication for the transmission of data. This is exactly what the communications industry, represented by companies like Qualcomm, has been working to achieve, and with the advancement of 5G and related technologies, the vision of the past is rapidly becoming a reality. 

Those who have understood the background knowledge of wireless communication technology should have heard of the concept of Shannon's limit, which simply means that the higher the data transmission rate of a single channel, the more noise it generates, and the smaller the probability of correct transmission, eventually reaching a point where the coding algorithm is unable to correct errors, thus becoming an invalid transmission. This phenomenon, similar to entropy increase, cannot be avoided, and better coding can only reduce the loss, and the marginal effect will become more and more obvious with improvement. 

This law determines that there is a limit to the bandwidth that can be achieved in a given frequency band, and the best way to really improve the overall carrying capacity is to broaden the available spectrum. Within the 14 radio bands defined by the International Telecommunication Union, the bands used for communication are mainly located between long wave (kHz class) and millimeter wave (100 GHz class), and applications from many different fields define their own bands within this range. We are familiar with the cell phone signal and Wi-Fi are within it, for example, 5G Sub6 used in the band between 3GHz ~ 6GHz, while the Wi-Fi band is concentrated in 2.4GHz and 5.8GHz. 

According to foreign media reports, on Thursday, local time in the United States, chip giant Qualcomm announced the first Wi-Fi 6E chips, which should be faster and more reliable because they can access a wide range of additional radio waves. 

Qualcomm released a total of two sets: for routers and cell phones, respectively, with the former available for immediate shipment, while the latter should ship later this year. The key feature of all these chips lies in support for Wi-Fi 6E, which takes advantage of the newly opened 6 GHz spectrum for Wi-Fi by the U.S. Federal Communications Commission (FCC) last month. This is the largest expansion of the Wi-Fi spectrum ever and should result in some huge performance gains. 

These Wi-Fi 6E handset chips are part of Qualcomm's FastConnect family and will often eventually be integrated with Snapdragon chips. There are two options at launch: FastConnect 6700 and FastConnect 6900, with maximum theoretical speeds of 3Gbps and 3.6Gbps, respectively. Qualcomm vice president of technology Jones (VK Jones) said: "I personally expect that this chip will be put into use very soon, especially in the high-end cell phone segment. " 

It is not entirely clear whether these chips will be applied to next year's flagship products. Qualcomm has introduced top Snapdragon chips this year, but currently uses the FastConnect 6800, which does not support 6 GHz. Qualcomm said handset makers have the option of using these newer Wi-Fi chips, but it's unclear how many manufacturers will work to add 6 GHz support rather than wait for a new generation of Snapdragon chips to come out that support 6 GHz by default. 

In addition to the mobile chips, Qualcomm has also released a number of Wi-Fi 6E chips for routers. They are part of the Qualcomm Networking Pro family and will come in a total of four versions. The maximum theoretical speed of these chips ranges from 5.4Gbps to 10.8Gbps. Qualcomm envisions mesh routers using these chips and using the new 6 GHz spectrum as a backhaul to wirelessly connect these units, freeing up the 5 GHz spectrum to communicate with devices. 

5G promises lightning-fast network speeds and the ability to power new technologies such as self-driving cars and advanced augmented and virtual reality experiences. But while 5G brings us convenience and speed, it also raises some concerns about whether the ultra-high frequency radio waves used by 5G will have an impact on public health? 

Mobile operators around the world are racing to deploy fifth-generation cellular technology. The largest cell phone manufacturers are also preparing their 5G phones. U.S. President Donald Trump has also made it clear that the U.S. cannot afford to fall behind other countries in this technology. At the time this technology was proposed, some scientists had raised concerns about the high frequency spectrum, so that the high frequency radio wave technology could have adverse health effects on the public.