It is challenging to function in the world of communications technology today without hearing a constant stream of dialogue around 5G wireless communications and how it will transform modern manufacturing. It can be tough not to be skeptical and dismiss much of the talk as simply hype.
The good news is that as 5G evolves it will bring significant benefits that may change the way we handle factory communications; and as manufacturing becomes more modular and mobile, reliable wireless communications will be critical for successful outcomes.
In this article we will take some time to distill what 5G is and which core pieces will have the most impact on industrial communications. To learn more on 5G and its impact on the factory floor, register for our techtalk below:
When we think of 5G wireless, the common perception is that it is a completely new piece of technology. It is actually an evolution of existing wireless standards that adds additional bandwidth and functionality to address some of the critical needs of consumer, commercial and industrial usage.
The term 5G is a marketing term created by the 3rd Generation Partnership Project (3G PP) to describe the 5th generation of mobile communications. 3G PP was founded in 1998 as global organization built around maintaining and evolving the standards for cellular networks such as GPRS, EDGE and UMTS. These cellular networks formed the basis for 2G and 3G communications which are used by several of the Mobile Network Operators (MNOs) on the market. Other MNOs based their 3G networks on the competing CDMA2000 specification at the time. These networks were based on different parts of the frequency spectrum and many of the cellular end devices could only function on one or the other at the time. This made it very difficult to roam in countries where one technology was dominant.
With the evolution of the LTE standard and 4G, the MNOs coalesced around the same technology, but this did not necessarily lead to cross-compatibility for cellular end devices. With LTE and 4G, spectrum was sliced into specific bands and MNOs would prioritize a certain band for their communications that was often unique. Some cellular end devices were compatible across multiple bands and could support connectivity to multiple MNOs, but it was not universal. The key realized benefits for 4G and LTE communications were data rates up to 20 Mbps, which were around 10 times those of the 3G standards.
5G has been developed to address several market occurrences. The first is that computing is becoming mobile at an exponentially increasing rate, which is creating strain on existing networks to deliver data and content at reasonable speeds. Today there are about 1.5 connected mobile devices for every person on the planet and many are using them as their sole platform for computing. In 2016, the average consumption per user was 1.7 GB of data per month and this is only increasing with some recent estimates of US data being over 13 GB/month. 5G will need to address higher data rates and increasing usage of mobile networks. The Enhanced Mobile Broadband (eMBB) part of the specification is one step in addressing this need.
The second occurrence that is driving development of 5G is the increasing presence of automation. Manufacturing is becoming increasingly modular and mobile machinery mounted on autonomous vehicles is beginning to replace fixed-position assembly lines in many industries. For automated tasks in manufacturing, networks with high throughput and reliable low latencies are needed. The Ultra-Reliable Low Latency Communications (uRLLC) portion of the 5G specification evolved to address these demanding applications.
Lastly, not only are more humans connecting to the internet with mobile devices, but intelligent devices are looking to gain internet connection as well. Devices such as sensors that provide feedback from industrial equipment need to connect directly to the internet for publishing critical data to analytics applications. In this scenario, high throughput and high data volumes are not needed, but these may exist on densely populated networks that need to run on very low power. This is where the Massive Machine Type Communication service under 5G is most useful.
One thing to keep in mind is that while the services that exist under 5G have been well defined, the chipsets needed for implementation are still arriving to the market and it may still be 1-2 years before we see broader adoption. As we look to the future, let’s think about how each of these services can be of benefit.
Enhanced Mobile Broadband (eMBB) is the service under 5G primarily focused on improving the throughput for cellular communications. Some of the numbers that have been proposed from 3GPP are network speeds between transmitters and receivers that top out at 10 Gbps, though that would be under optimal circumstances. To accomplish this, one of the critical needs is to have additional wireless spectrum available.
With wireless communications, assuming all other things are equal, throughput is proportional to the frequency of the spectrum. For example, 5 GHz wireless can transmit with higher throughputs than 2.4 GHz wireless. 5G will be implementing frequencies that are about an order of magnitude higher than many of the current cellular technologies, which will help deliver on increased throughput. These frequencies exist in what is called the millimeter wave portion of the spectrum. With higher frequencies, the effective range is reduced as these waves experience free space energy loss more rapidly and are also more heavily impacted by reflection and absorption from obstructions. With reduced range, this will require a denser infrastructure to support wide deployment.
Another way to increase throughput in a wireless system is to have additional spatial streams for data to pass through. In wireless communications, this is referred to as MIMO (Multi-Input Multi-Output) where multiple transmitting and receiving antennas are implemented on devices. 5G deploys Massive MIMO to significantly increase spatial streams and uses Beamforming, which provides increased network integrity through constructive interference of in-phase signals and destructive interference of out of phase signals. With Massive MIMO and Beamforming, increased throughput can be seen even in the traditional portions of the wireless spectrum used for cellular communications.
In the industrial space, use cases that would benefit from this throughput enhancement would include Augmented and Virtual Reality, Digital Twin, Remote Connectivity for programming equipment, and autonomous vehicles.
Making 5G useful for automation means reducing the network latency, reducing the variance in the network latency and making sure the network is reliable. Existing wireless communications can have reasonably low latency, but it can often vary in unpredictable manners depending on noise and congestion, which may also impact the reliability of the network. With 5G, the uRLLC service addresses this through a combination of packet optimization, signal diversity and packet prioritization.
With traditional cellular communication, transmission of data is handled through a grant process. The user end device (ex. mobile phone) sends a Scheduling Request (SR) to the base station, which the base station then assigns resources and issues a Scheduling Grant (SG) to the user end device. Essentially, the user end device asks for permission to transmit to the base station before it sends data. Once the SG is issued, the user end device can send data. This happens each time a new block of data is issued and is the key source of network latency on cellular networks.
With uRLLC, the interaction is grant-free, and the user end device no longer needs to request resources from the base station. The device is given intrinsic permission to transmit data which reduces considerably the latency in the system. As 5G technologies improve, latencies that approach 1ms may be realized.
Another key aspect of the uRLLC service is using diversity to improve network reliability. Diversity means using multiple means of transmitting the same piece of data to ensure that it is received. With uRLLC on 5G, this consists of frequency, time and spatial diversity. Frequency diversity involves transmitting data across multiple subcarriers within a slice of the frequency spectrum and is often built into the modulation used by the radios. With 5G, there can be up to 10 subcarriers. Time diversity involves transmitting the same piece of information at a slightly different time and provides less benefit as network cycle times are already very short. Spatial diversity through Massive MIMO provides the greatest benefit as this involves multiple transmitters and receivers duplicating information on the device.
Lastly, uRLLC packets are given priority on the network and can pre-empt eMBB transmissions. This increased Quality-of-Service reduces latencies associated with other traffic and ensures a high degree of available network resources.
In the industrial space, use cases that would benefit from this throughput enhancement would include Mobile Robotics, Remote Machine Control, Motion Control and HMI.
As the need increases to capture more data and effectively measure equipment, large-scale networks of sensors will be needed. Having wireless networks that can scale effectively will be critical and the mMTC service within the 5G specification addresses this.
For sensor applications, the data payloads tend to be very light. Instead of gigabytes of data, often just a few bytes of data are being transmitted. This means that high speed networks are not as critical since light payloads on a slower network can still be handled in a timely manner. Additionally, many of these new sensors being deployed are battery powered so low energy consumption is critical. Transmitting higher energy waves can negatively impact the battery life of a device.
Whereas eMBB focused on the higher ends of the spectrum to provide better throughput, mMTC uses the lower ends of the supported spectrum around 1 GHz. This still provides ample bandwidth to support the timely processing of data while using low-power radios. Additionally, denser networks of devices can be supported with up to 1 million devices/km².
Industrial applications where this would be useful include machine sensors for monitoring temperature and vibration, and positional sensors for fleet management.
5G provides a lot of benefit from a technological perspective with support for higher throughput, lower latencies and denser networks.
As with most wireless networks, adoption will happen first in the commercial and consumer spaces with pockets of available public networks already starting to appear. The industrial space will start to follow in adopting after seeing the technology vetted in the consumer/commercial space, but it will be critical that manufacturers have access to private and semi-private networks as most will not be comfortable with their data flowing across public networks.
It is going to be interesting as we may live in a future where almost all data moves across wireless networks.