Let’s take another look at the diagram I showed you in my previous post about 5G:
I focused last time on enhanced mobile broadband (eMBB) and the innovation it represents for consumer applications. In this post, I’ll focus on the advantages of 5G when you develop applications for mission-critical control.
Industrial automation — Faster than humans can think
The use cases for eMBB, such as video streaming and lightning-fast browsing, are important, but they are not always mission-critical. For instance, if network latency results in an additional half-second to download a video or render a web page, it will probably not ruin the consumer experience. But in preventing a traffic accident or running an industrial robot, that half-second is important. In scenarios like those, delay and failure are not an option.
That’s why the engineers responsible for 5G specifications went beyond consumer use cases and designed 5G NR (New Radio) to satisfy or exceed requirements for mission-critical control. Those requirements affect your development work in areas like industrial automation, which is one of the most difficult use cases to cover. They also affect your work in applications such as:
- smart-city infrastructure
- automated guided vehicles (AGV)
- robots and drones
- safety-related and autonomous systems in vehicles
- remote medical procedures
Applications like those won’t succeed in conditions of low reliability (connection loss) or high latency (delays in sending packets of data from one point to another).
Why the emphasis on low latency? Because Industry 1.0 (mechanization), 2.0 (electrification) and 3.0 (digitalization) relied on the human factor to connect processes. Industry 4.0 relies on 5G to connect them by wringing out latency to fractions of milliseconds.
Enhanced ultra-reliable, low-latency communication (eURLLC)
To provide the network reliability and availability needed for mission-critical control, the upcoming Rel-16 of 5G NR includes enhanced ultra-reliable, low-latency communication. eURLLC is designed to guarantee “six nines” of reliability — or packet loss as low as .0001% (10-6%, or one packet per million) — and latencies below 1 millisecond. It is also designed for multi-connectivity to create redundant links that ensure reliability.
For instance, to achieve such ultra-low latency, 5G NR allows for scalable slot duration down to 125 microseconds, 1/8th that of 4G LTE, as shown below. One of the goals of this scalable slot duration is to reduce the delay in waiting to transmit data, preparing it, transmitting it, processing the received data and sending feedback.
Scalable slot duration in 5G NR at different rates of sub-carrier spacing (SCS)
Adapting to the needs of industrial automation
There’s no telling when an autonomous machine will send a failure code or when a temperature sensor will fire. To support mission-critical applications like industrial automation, 5G NR includes mechanisms for transmitting high-priority messages among all of the other data and services running on the network.
One step is to upgrade existing industrial Ethernet networks like PROFINET and EtherCAT to wireless 5G. For that, eURLLC also incorporates time-sensitive networking (TSN), a collection of IEEE 802.1 standards that enable synchronization of machines. TSN offers deterministic packet delivery — known transmission times for real-time packets — instead of the variable, best-effort transmission times typical of Ethernet. 5G defines TSN adapters that provide Ethernet functions and connect TSN systems to devices.
Another technique punctures nominal traffic and multiplexes mission-critical services with it. It listens for unscheduled, high-priority messages amid regular voice and data services, and allows for transmission of those messages at any time. For example, in safety-related systems, puncturing will allow commands to get through reliably and without delay. The 5G NR framework allows nominal traffic to recover after a puncture without incurring yet more latency from an excessive number of retransmissions.
Device-to-device communications and spectrum sharing
Mission-critical devices need to communicate device to device (D2D) and exchange real-time information directly when they are temporarily out of network coverage. That kind of direct link in a multi-connectivity framework is exemplified in Cellular Vehicle-to-Everything (C-V2X) as part of LTE Advanced Pro, carried forward into 5G.
Also, new spectrum sharing techniques in 5G NR allow for more-predictable quality of service (QoS) and synchronized operation among 5G nodes. They enable Coordinated Multi-Point (CoMP) for URLLC, which we believe will be required for industrial IoT applications such as factory automation.
In short, when it comes to mission-critical control, the main advantages to 5G lie in ultra-reliable, low-latency connections between devices and the network. Plan your 5G applications around greater availability and less delay than ever.
To find out more about the role of 5G NR in can’t-fail industrial scenarios, have a look at our six-minute video titled “Ultra-reliable 5G NR for Industrial IoT.”