5G mobile networks are quickly becoming a reality. In fact, the International Telecommunications Union (ITU), a specialized agency of the United Nations responsible for issues that concern information and communication technologies, set a goal to finish many of the required technical designs by the end of 2020. This article will help you understand both the need and purpose of 5G mobile networks, and give you a high-level knowledge of the design and technologies behind 5G.

A key reason for the introduction of 5G technologies is that LTE networks simply can’t handle today’s growing mobile dependency. For consumers, it’s not uncommon to have three or more devices connected to a mobile network. Additionally, the content these devices share—like high quality photos and video content—is becoming more data intensive.

Beyond consumer behavior, several technological advancements also require 5G networks. Self-driving cars need access to a low-latency network that is able to prioritize network traffic more intelligently. Another general area 5G needs to serve is internet of things (IoT) device deployments in healthcare, manufacturing and other verticals. Often, these devices deploy on a massive scale. Think sensors and controllers in a manufacturing plant—something LTE networks can’t accommodate.

A final shortcoming of LTE networks is their reliance on regional point of presences, or POP. In brief, your cell data has to travel a long way to deliver internet. Internet served through WiFi has a lower latency, as the traffic is processed through a local ISP. In order for 5G to achieve low latency, cell data can’t rely on regional POP. 

Knowing some of the shortcomings of LTE, can you predict the design objectives for 5G? The ITU has outlined four broad objectives:

This is the technical component of 5G. It outlines speed and latency requirements, security, growth and energy efficiency, among other things.

This refers to the large quantity of data created by the end user, including things like pictures, movies or sensor data, as well as the data available on a local network or the internet. Having high speed, low latency, highly-reliable access to this data is critical for next-generation technology to operate correctly.

This focuses on energy efficiency and optimization of the technology. (Powering a cell site is expensive, and there are tremendous cost savings available with more efficient use of power.)

Access to the internet is critical to the success of an individual or a culture. Organizations should provide a network that’s accessible to as many people as possible, at a cost that isn’t prohibitive to use.

Alongside the design objectives established by the ITU are a set of realistic technical design goals and milestones created by the 3rd Generation Partnership project (3G PP) which try to align with what hardware manufacturers can actually build.

5G networks should allow users to enjoy a download data rate of 100 mbps. Furthermore, the latency on 5G networks should be less than 20ms. Other applications that require the lowest latency, like self driving cars, will require less than a millisecond of latency. Self driving and other systems will need communications speeds of more than a gigabit per second.

Because of the new uses for 5G networks, like self-driving vehicles and IoT devices, it's paramount that the integrity of the data passed on the network is maintained. Tampering with data on a 5G network has the potential to cause catastrophic consequences.

To make 5G more sustainable and pervasive, providers will begin by rolling out on existing LTE technology. Then, the network will migrate to standalone 5G technology that doesn’t require any use of LTE. Taking a giant leap forward and beginning with entirely new technologies is expensive and unrealistic based on current hardware.

As mentioned already, powering a cell site that allows for the speed and latency goals could be expensive, especially as usage goes up. The engineers designing the hardware will make use of several technologies to reduce the energy footprint for delivering 5G networks.

The objectives and goals are set, but what technologies will actually power 5G? While there are undoubtedly many innovations in this space, there are five that are most critical: millimeter waves, small cell deployments, massive MIMO, beamforming and full-duplex communication.

All wireless communication utilizes a piece of the electromagnetic spectrum. Regulating bodies divide that spectrum into channels and charge networks a fee to use those channels. Currently, carriers use microwave bands. 5G, however, will use millimeter waves, which fall between microwaves and infrared waves. Using millimeter waves offers many more channels than microwaves, which is critical for the use of the technologies we’ve discussed. However, it comes with one challenge.

The smaller the wave, the smaller the range. Small waves also have difficulty penetrating objects. Think about your own TV remote. It uses infrared waves. If you leave your living room, or interrupt the signal, it won’t work. On the other hand, microwaves can penetrate buildings and travel for miles. Millimeter waves, while not quite as bad as infrared, have a range of about one kilometer and won’t be able to penetrate most buildings. This poses serious challenges for 5G use in dense cities.

How will 5G technologies combat this? It’s actually a fairly simple solution—just build more, but smaller, cell deployments. This would allow more radios in an area to extend the range of 5G networks. Unfortunately, this creates another problem as the signals can bounce off buildings, causing potential interference.

As you may have guessed, the next two solutions address the problems created by small cell deployments. The first is called massive MIMO, or multiple input, multiple output, and the second solution is called beamforming. Together, these technologies use multiple antennas to send and receive signals. They can create directed beams of signal, boosting strength where it’s needed and cancelling out the signal when it’s not. It makes for less interference and stronger signals for the most important technology.

Our final technology implementation, full-duplex communication, is all about increasing efficiency and speed. Picture a walkie talkie you used as a kid. Only one person could speak at a time, right? This is called half-duplex communication, meaning only one signal sends across the channel. Now think in terms of data. LTE, while allowing you to send and receive data at the same time, actually uses two channels to do so, one to send data and the other to receive it. New technology used in 5G will allow both sending and receiving data to occur on the same channel. This doubles the capacity of a channel and results in massive efficiency gains.

Still, none of the technology mentioned here solves the penetration problem. Using 5G in a building will still be a challenge. Femtocells, or wired internet connections between a radio inside a building and the carrier, can help. But they aren’t very efficient yet. What’s more likely is that current LTE channels will continue to be used in 5G deployments, while outdoor deployments will make use of millimeter waves and the rest of the implementations mentioned in this section. 

The technologies needed for the 5G revolution are within reach. 5G will power connected, smart devices in the internet of things and help bring self-driving cars to the roads en masse. However, there are still challenges to overcome and pitfalls that will require continued innovation.