5G is the fifth generation of cellular network wireless communication. It is designed to offer better performance than 4G LTE, which is its predecessor. This is accomplished in large part by utilizing higher frequency radio bands. According to the ITU guidelines, 5G is expected to offer download speeds of 20 Gb/s and upload speeds of 10 Gb/s. Latency in a 5G network could be as low as 4 milliseconds for mobile devices, and in the cases of Ultra-Reliable Low Latency Communication, it could be as low as 1 millisecond.
How it works
High frequency radio waves cycle more rapidly, thus giving more opportunities to transmit bits of data each second. The functional problem with high frequency radio waves is that they are more easily dissipated or absorbed, so they do not travel as far and are more easily blocked by structures and landscape. To deal with this issue, 5G actually utilizes three bands.
- Low-band 5G: Uses frequencies lower than 1GHz, which are durable but slow for communication. This is likely to be useful inside buildings, and at long distances from cellular towers. Communications speeds using this band will be similar to the speed of 4G.
- Mid-band 5G: Uses frequencies in the 1-10GHz range. This frequency range offers greater speed, and a practical range of around a half mile. In the U.S., only Sprint had available frequencies in this band which it could utilize at the time 5G was released. Multiple antennas on the same cell tower are grouped together using "Massive MIMO" to improve penetration and coverage area. Some companies such as Sprint are also using a process called Beamforming, which sends a single focused signal to each individual user in the service cell.
- High-band 5G (also know as millimeter-wave or "mmWave"): Uses frequencies in the 20-100GHz range. This offers high speed communication, but a range of only about 800 feet. Cell carriers are expected to deploy a large number of "microcells," which are low-power base stations (transmitting at only 2-10 watts), and a smaller number of higher power "macrocells" (transmitting at 20-40 watts) to deal with this problem.
Additionally, 5G uses OFDM encoding, which is similar to what 4G LTE used, but is more efficient. This results in about a 30% speed increase over 4G LTE, when the same radio bands are used. The other main reason for significant speed improvements is that 5G uses larger channels than its predecessors. 4G LTE used 20MHz channels, while 5G channels can be up to 100MHz, with Verizon using up to 800MHz at a time. This offers a much larger "pipe" through which data can be transferred.
Problems and concerns
The benefits which 5G technology offers do not come without drawbacks. There are a number of known and suspected issues with 5G.
5G comes with practical issues of limited range, necessitating a much greater quantity of microcells. These low power base stations each need either wired internet connectivity, or wireless backhaul connections. In order to deploy 5G to the public, more infrastructure is required. Complicating matters further for carriers, there is some public resistance to the installation of base stations. Some dislike having them for aesthetic reasons, while others oppose them for based on health concerns. This has been an issue in the past, for earlier generations which utilized lower (further traveling) radio frequencies. In order to deploy 5G effectively, there must be many more localized base stations than were required by previous generations of the technology.
At the time of official release in 2019, 5G base station equipment was only available from China. Most notably, Huawei is a key provider of this equipment. Huawei came under attack not long before the release of 5G, for allegedly placing backdoors in their network routers on purpose. However, Huawei claimed that this was nothing malicious, and that they had simply been using the telnet service during development, and had forgotten to remove it before sale. Regardless, the US began calling on its allies in the "Five Eyes" to ban Huawei's equipment for security reasons. Therefore, when the company released its 5G transceivers and related equipment, a number of western countries were very suspicious of how secure it really was.
Another cause for concern has been over the potential health impact of extended exposure to high-frequency radio emissions. There have been many studies on how radio-frequency radiation may affect human health. Some have found no significant affect, while others have reported a myriad of problems. While radio emissions are a form of non-ionizing radiation, there is still some suspicion that it may tend to cause cancer. This has led to the World Health Organization classifying it as a potential 2B carcinogen in 2011. A collection of studies on electromagnetic radiation have resulted it determinations that it may cause DNA single and double strand breaks (possibly resulting in cancer), oxidative damage (leading to tissue deterioration and premature ageing), disruption of cell metabolism, increased blood brain barrier permeability, melatonin reduction (leading to insomnia and increasing cancer risks), disruption to brain glucose metabolism, and the generation of stress proteins.