The question is not whether, but how IEEE 802.11ax (also known as Wi-Fi 6) and 5G are driving wireless mobile communications in the industrial environment. Siemens supports both technologies in order to offer optimal solutions for the most diverse requirements.
We did the first step by introducing Wi-Fi 6 Access Point AND Client Module – featuring the first Industrial Wi-Fi 6 Client Module on the market. Wi-Fi 6 is the first WLAN standard to no longer mainly focus on greater bandwidth, but on the more efficient use of frequencies by each individual client as the number of participants increases. These features can now be leveraged within industrial components – our new SCALANCE WxM766-1 devices.
Wireless in Industries
Here’s my take: Wireless LAN in the industrial environment has long been much more than the mere wireless connection of a few stationary participants. With proprietary industrial-oriented additional functions, the so-called iFeatures – such as the industrial Point Coordination Function (iPCF) – Siemens already has augmented earlier WLAN standards with real-time capability and prepared them for the most demanding industrial applications. Applications with mobile participants such as crane trolleys, automated guided vehicles (AGV) and shuttle systems, high-rack warehouses/ rack feeders, overhead monorails, and increasingly mobile robots in modular production environments are now established worldwide. The technology has become an integral part of the world of automation. Even more so in the end-to-end digitalized factory with more and more IIoT devices and mobile virtual/augmented reality devices for the visualization of data and processes, e.g., for assisted work. The number of participants in wireless networks continue to rise, and with it the need for even more flexible, efficient communication. Still handling and coordination, service and maintenance must remain easy to manage for the user. For this, we at Siemens added the SCALANCE WAM766-1 and SCALANCE WUM766-1 to our Industrial Wireless LAN portfolio, featuring the latest WLAN standard – IEEE 802.11ax – the sixth generation, succinctly dubbed Wi-Fi 6 by the official Wi-Fi Alliance..
Communicating more efficiently bit by bit
A major step towards higher efficiency is made possible by the OFDMA (orthogonal frequency-division multiple access) function, a method of data transmission already established in mobile communications but new for WLAN. Up to now, WLAN utilized the orthogonal frequency-division multiplexing (OFDM) method. With it, only one client can communicate with the access point at a specific time and the client exclusively occupies the communication channel for data transmission.
With OFDMA, the communication channel is divided into multiple subchannels, so-called resource units (RUs). These subchannels can be variably bundled and used by different clients. In this way, data can be transmitted simultaneously and therefore at shorter intervals. This can reduce latency, especially for small packets such as PROFINET telegrams, and ultimately lead to shorter cycle and response times for automation solutions.
A WLAN with end-to-end OFDMA-capable access points and clients enjoys various advantages. For instance, more participants can communicate in a shorter time than before, or more data can be transmitted in the previous time window with the same number of participants. This, for example, makes it possible for an automated guided vehicle (AGV) or a skillet conveyor to respond more quickly to unforeseen events, such as people in the travel range. It can therefore be operated at a higher speed without increasing the risk. In a high-rack warehouse, this means significantly higher transshipping rates. As I was analyzing the feature it is also clear that OFDMA ‘out of the box’ will not bring all this benefits as it.
OFDMA is the core Wi-Fi 6 feature. All of the main features are described and for industrial use cases classified within the following whitepaper:
Whitepaper: Wi-Fi 6 in the industry
Sustainability: Reducing energy consumption
The SCALANCE W700 devices incorporate a dedicated hardware sleep mode and a digital output. This helps save energy and extend the service life and maintenance cycles of battery powered mobile devices connected via WLAN. It enables energy-efficient operation fleets of automated guided vehicles (AGV fleets), for example.
Greater efficiency also for industrial applications?
I mentioned already, that ‘out of the box’ will not alone portray all requirements of automation solutions in the various industries. To use OFDMA in real-time, the correct scheduling (communication planning or communication control by the access points) must be implemented, for example. The critical point in wireless communications, namely the transition of a client from one access point to another, was neither considered nor improved in the standard. Those two aspects will require additional industrial-oriented adjustments in the manner of the already familiar industrial feature (iFeature) iPCF for deterministic real-time communication.
The trend in automation is towards automation protocols with hard real-time requirements that are operated in parallel with data-intensive applications. To operate all applications trouble-free via a wireless connection, extensions to the mechanisms already existing in the standard are needed.
To not only use the possibilities of the new standard, but to go beyond it and create real added value in automation with regard to real-time and reliability – that is exactly the aspiration Siemens is already implementing with Industrial Wireless LAN and will also be implementing with Wi-Fi 6.
Get your hands on this new generation of Industrial Wireless LAN!
Take the step with us into the future of wireless communication.
Here’s all you need to start the journey:
Beside your Siemens contact I, Kilian Loeser, am happy to receive your questions!