IoT Hacking Series #9: The Technology Behind 5G

It has been 3 years since our last post about 5G and the benefits it provides. Why haven't we covered the new technology in depth? What have been the latest updates to 5G, and should you already prepare for the launch?

All the questions will be covered in this and next week's deep dive.

Let's see how far the new generation of cellular connectivity has become with a technical look at 5G. If you are not that interested in all the technical chit-chat, then make sure to have a look at our next post where we will cover what 5G means for the end-user.

Quick recap

Following are the main facts that are still relevant today, but were covered in our last 5G blog post:

• Downlink peak data rate: 20 Gbit/s, uplink peak data rate: 10 Gbit/s.

• In dense areas, experienced downlink data rate 100 Mbit/s, uplink 50 Mbit/s.

• Can handle at least 1M connected devices per 1km2.

• Will Cover connections and speeds when driving at up to 500 km/h, for example, in trains.

• Interruption time, when migrating between radios, should be zero.

These points were set out already in 2015 as a part of the IMT-2020 Standard (International Mobile Telecommunications), which specifies the requirements for 5G networks, devices, and services. As the name suggests, the standard is aimed to be completed by 2020.

IMT-2020 is a followup standard for previous technologies like 3G(IMT-2000) and 4G(IMT-Advanced).

Technological solutions that make 5G happen

A series of new solutions need to be implemented to fulfill all the high specifications and goals set for 5G. Each technology comes with its limitations, which the next solution aims to fix.

That's why there's a set of 5 new implementations that lay the foundation for a full 5G rollout.

We will try to keep the explanations understandable of each technology, but bear with us for now:

Millimeter Waves

Millimeter wave technology allows transmission of data on high frequencies between 30 GHz and 300 GHz. In comparison, 4G uses frequencies below 6 GHz.

The high frequencies allow faster speeds and are also less cluttered with existing cellular data.

But millimeter waves can not travel through buildings or other obstacles. It's has been found that even rain might absorb the signal. That is why there's a need for the next technology - Small Cell.

Small Cell

Before 5G, we deployed high powered cell towers that could broadcast signals over long distances.

But as we learned from the previous point, millimeter waves don't travel through obstacles. So, more cell towers need to cover the same area as before.

For a successful introduction of 5G, we need to deploy many small cells that can hand over the signal from one cell to another when a device travels from one point to another.

Massive MIMO

MIMO stands for Multiple Input Multiple Output, which means a cell tower with multiple antennas for receiving and sending. MIMO, as such, has been used already in telecommunications.

With the introduction of 5G, the number of different antennas increases tremendously. The more significant amount of antennas enhance connectivity and offer better speeds.

And yes, Massive MIMO comes with its cons. All of these antennas broadcasting in all directions can cause severe interference. That's why we need Beamforming.

Beamforming

Beamforming allows the sending of a specific stream of data to a particular user. This will prevent interference and let the cell to handle more devices at once.

Full Duplex

Currently, antennas are capable of only transmitting or receiving data at any given time. Until now, the solution uses different frequencies for transmitting and receiving or for taking turns in sending and receiving.

Full Duplex will allow you to send and receive on the same wavelength, again boosting the speeds and number of simultaneously connected devices.

5G NR

5G New Radio (NR) is the Radio Access Technologie (RAT) that is developed for your device to connect to 5G. The new standard for the air interface.

5G New Radio is RAT beyond LTE. In simple terms, 5G NR will be the new standard that will replace 4G LTE. Soon you will see it displayed on the top of your phone.

To complicate things a bit further there are two modes for 5G NR:

• Non-Standalone mode (NSA)
  This mode will rely on existing 4G LTE infrastructure providing higher data-bandwidth and reliable connectivity. It's easier and cheaper for the operators to implement, but it will lack the core features like ultra-low latency and higher capacity of 5G. 
  
  
• Standalone mode (SA)
  This is what we can refer to as real 5G. SA mode will pave the way for new services that need the full potential like ultra-low latency and low power of 5G. 

The industry hasn't formed a clear consensus on which to implement first.

Some carriers are looking to launch the NSA mode to boost 5G adoption quickly. Others don't see the value in NSA mode and plan to implement the full SA mode from the beginning.

5G NR Standalone mode (SA) complete specification

Standalone mode is the actual core 5G that brings all the vast improvements for consumers and IoT/M2M deployments. The core system brings us three main use cases:

• eMBB (enhanced Mobile Broadband)
  eMBB aims to support consumer applications like HD video streaming and gaming.
  High peak data rates and support for high-speed mobility.

• URLLC (Ultra Reliable Low Latency Communications)
  The reliability of URLLC will support critical applications like eHealth, ultra-low latency(less than 1 ms air interface) will enable autonomous vehicles and remote control in manufacturing.

• MMTC (Massive Machine Type Communications)
  MMTC will support the massive IoT deployments that we have seen over the past years and which will increase even further. Connecting millions of low-power devices without congestion.

We will note dive deeper into the seemingly endless technical implementations of 5G. We believe that the points covered in this blogpost are the most important to have a first understanding of 5G technology or to lay the groundwork for doing more in-depth research.

If some parts are still unclear or you have further questions feel free to contact us at hacking [at] 1ot.mobi.

If this was too technical, make sure to check back next week for our followup post where we will bring out what 5G means for the end-user. We will answer questions regarding 5G pricing, 5G SIM cards, hardware modules and more!