What Is 5G? 4G vs. 5G
5G is the 5th generation of cellular network technology and, like each predecessor, offers higher data rates than the previous, lower latencies, and better bandwidth.
When compared to 4G, 5G offers bandwidths greater than 1 Gbps, a latency of less than 10ms, and an average speed of 200 to 400 Mbps, whereas 4G only offers a bandwidth of 200 Mbps, a latency of 20ms – 30 ms, and an average speed of 25 Mbps.
Even though 5G is incredibly new with its full roll-out expected by 2020, some countries are well into the process of adopting the new network. South Korea, for example, has installed 86,000 5G base stations. Meanwhile, several network operators in the UK have just released 5G in the past month.
While the technology is now available, only a handful of devices on the market actually support 5G and so wide access to 5G won’t be expected until the technology matures.
The Tradeoffs of 5G
So, it can be seen that 5G offers significantly more of… everything… but surely there must be a catch to the far superior specs?
As a matter of fact, 5G does have an issue with implementation and it comes down to the frequencies at which it operates.
Technologies such as 4G operate at three main frequency bands which are 800MHz, 1800MHz, and 2600MHz—which have wavelengths in the centimeters (for instance, 2400MHz radio waves have a wavelength of approximately 12cm). This wavelength allows large radio masts to have a range of up to 35km—but, due to practical limitations, cell towers will often be placed within several km of each other.
5G, on the other hand, operates on several frequencies which include the already-used LTE bands (600MHz to 6GHz) but also the millimeter-wave bands of 24GHz to 86GHz.
The result? While higher frequencies allow for higher bandwidths, they come at the cost of the wavelength.
As the wavelength of radio waves reduces, its effective range reduces for a number of reasons, including interference, diffraction, and reflection. Since 5G operates at significantly higher frequencies, as well as having higher bandwidths, it is not able to fully operate on 4G radio masts and therefore new 5G base stations are required.
The move from passive antennas to active antennas is expensive. Image of a millimeter wave phased array antenna module used courtesy of IBM Research
But the replacement base stations are not just differently-shaped metal rods attached to some coax; they are a whole new type of antenna with some incredible capabilities.
5G Antenna Technologies: The Advantages of Beamforming
Radio antenna come in many wonderful shapes, sizes, and forms. From horn antennas that search the cosmos for microwaves to dipole antennas that "listen" to Jupiter to inbuilt PCB antennas in IoT devices, antennas are everywhere.
But the radio antenna in 5G networks are arguably a whole new class of antenna with some rather incredible abilities.
The combination of small wavelength radio waves and the requirement for many simultaneous connections means that 5G masts need more than 100 radio elements that make up a phased array.
Since there are many elements next to each other in grids, this allows for some incredibly intelligent beam steering to individual users. When combined with complex algorithms, the 5G radio base station can determine the best way to steer the beam to provide the highest data connectivity. The use of beamforming therefore also helps to reduce the energy wasted by the mast as individual users are targeted rather than radio waves being emitted in all directions.
The use of beamforming additionally helps with reducing interference with other base stations. The result is a further increase in bandwidth. Another way to look at it is that the more devices that share the same frequency band, the less time each device has access to that frequency band (they all have to take turns to use the band). If individual devices are targeted with a beam, each device can maximize their use of the band without interfering with neighboring devices as they will only be communicating via the beam.
Image used courtesy of Qorvo
Since the range of the 5G antennas is significantly reduced due to the use of higher frequencies, the 5G network topology will be more focused on many short-range antennas as opposed to several large cell towers that cover large areas.
Qorvo, for example, demonstrates a 5G network topology with multiple smaller cells that cover specific areas and then connect to a central core network with picocells covering indoors, microcells covering an urban area (small built-up area), and a macro area coving a suburban area.
Concerns About the Rise of 5G?
Since the rise of radio communications to daily prominence, there have been various parties concerned with the effect of radio waves on health. The onset of 5G has somewhat revived these concerns as new hardware presents fresh opportunities for misunderstandings, but also for education.
Many experts dispute the idea of health-related concerns because the radio waves used in mobile technology are in the centimeter range, which are non-ionizing (though they can cause heating). 5G, however, uses much higher frequencies which are in the millimeter range. Since the higher frequencies put the 5G radio signals closer to the ionizing range—and with the increased number of base stations needed—there are those who question the technology's safety. Some of these concerns are borne from extant studies, such as one that showed an increase in heart cancers in rats when constantly exposed to mobile radiation. Others anxieties arise from the argument that more studies are needed on the long-term effects of exposure to EM radiation.
The other concern of 5G is how and who implements the technology. Despite concerns from the US, the UK is implementing 5G with technology supplied by Chinese megacorporation Huawei, which has some questioning whether Huawei's 5G systems will be secure due to the heavy involvement of the Chinese government (to the point where each company will have an appointed official who monitors the business).
Because the adoption of new technologies can be contingent upon public opinion (as in the case of consumer trust affecting IoT adoption; link opens PDF), these issues will likely need to be addressed over time for a smooth transition to 5G.
Unlike its predecessors, 5G is a revolutionary change to network infrastructure with reliance on phased arrays, beam steering, and considerably higher frequencies.
Network providers will have to completely rehaul their infrastructure in order to be able to provide 5G. Not only are the new antennas far more complex than their predecessors, many more antennas will be needed due to their limited range.
Will 5G be the first worldwide urban Wi-Fi? Could 5G replace urban Wi-Fi entirely? Will communities be able to implement the new infrastructure smoothly? Only time will tell!
Read More about 5G
- Mobile World Congress Kicks Off in Barcelona with 5G at the Forefront
- How Will 5G Networks Improve Location Awareness?
- Communication Processors March on But 5G Demands Much More
- First 5G Wireless Standard Released