In our interconnected world, there is high demand for a wide range of communication technologies. Today’s market can offer a solution for any application – whether wireless or with physical cables.
Whether we are talking about a self-organising production process in Industry 4.0 or highly automated driving in cars. Data is transferred everywhere. At the same time, requirements for communications technologies are becoming more demanding. Not only do ever-growing data volumes need to be transferred at ever-higher speeds. As little energy as possible should be consumed in the process. Connectivity should also be quick and easy to implement. In addition, certain applications require communications technologies that transfer data in real time (e.g. to transmit safety-relevant information without any delay).
No technology can satisfy all requirements simultaneously. So a wide range of standards and systems have since become established and continue to be refined. All begins with the wireless standard that almost everyone uses at home today: Wi-Fi. The standard IEEE 802.11 was first defined as a mandatory interface for local wireless networks 20 years ago. Since then, the technology distributed under the name Wi-Fi has become a familiar and firm fixture in all kinds of applications. Wi-Fi 6 is the most up-to-date version.
During the development of Wi-Fi 6 – or WLAN standard 802.11ax – the foremost aim was to increase bandwidth. The previous standard 802.11ac achieved a maximum data transfer rate of 1.3 Gbit/s. Wi-Fi 6 now uses a new mix of technologies. Used to achieve a fourfold increase in the network bandwidth and number of simultaneous users while reducing average network latency from 30 milliseconds to just 20. With Wi-Fi 6 – and under ideal conditions – transfer rates of up to 11 Gbit/s are possible. Furthermore, the new Wi-Fi standard extends range, improves energy efficiency and boosts connection reliability. Another novelty is that the standard enables use of the 6-gigahertz (GHz) frequency band. In the USA, this frequency range is already approved for royalty-free use by WLAN, although this is still pending in Europe.
“With its expanded spectrum, the USA is giving the current Wi-Fi 6 standard a huge shot in the arm: under its official designation of Wi-Fi 6E (where the “E” stands for enhanced), WLAN in the 6 GHz band draws level with the 5G mobile-communications standard in terms of data-transfer rates and latency times. This opens up entirely new scenarios for use, such as in real-time applications like virtual reality,” Lancom founder Ralf Koenzen states confidently. His company manufactures network and security solutions for business and administration.
5G could also be a private wireless network
In this respect, Wi-Fi 6 technology competes with mobile-communications standards. After all, 5G is not only of interest for applications where data needs to be transferred over long distances. On the contrary, it can also be used to set up private mobile-communications networks, such as within a production facility. 5G promises minimal response times and speeds at least 100 times higher than the current LTE standard. This also enables safety-critical functions to be implemented in production processes. Process data can be recorded with latencies of just a few milliseconds and evaluated in real time, thereby optimising monitoring throughout the industrial process chain.
Professor Martin Ruskowski, Head of the Innovative Factory Systems research department at the German Research Center for Artificial Intelligence (DFKI) has the following to say on the matter: “More and more machines, devices and services are integrated into production networks. Traditional communication technologies are being dissolved and increasingly relocated to the virtual domain.” Especially when used with artificial intelligence. 5G mobile technology enables the seamless integration of autonomous systems and mobile platforms without physical cables. Making entirely new manufacturing methods a reality. “Communication with real-time capability is crucial in ensuring the success of Industry 4.0,” Ruskowski continues. “With 5G, the flexibility, adaptability and productivity of industrial manufacturing will increase dramatically.”
Communications technologies in real time
This is why work is currently under way to integrate 5G into communications standards such as Time-Sensitive Networking (TSN) as well. TSN is an Ethernet-based standard that provides low latency in data transfer alongside high synchronisation. Using this real-time technology allows data packets to be prioritised. Priority classifications can be used to make flexible decisions about the data requiring immediate availability versus categories where a delay is acceptable. For instance, TSN guarantees that safety- and security-critical data is transferred as a matter of urgency. And actually received when network traffic is heavy. In an overloaded network, this guarantees that a module has process stability – meaning that it will reliably continue to operate.
Data and energy combined
Over the past few years, Ethernet has been able to establish itself as a communication system in many areas. Whether in factories, cars or buildings. This not only applies to wireless connections, but also to those where data is transferred via cables. When compared with traditional bus systems, Ethernet boasts higher speeds, improved handling of large data volumes and lower costs thanks to its high energy efficiency. And not to mention flexible and economical bandwidth options. Nowadays, Ethernet protocols enable speeds of up to 400 Gbit/s with optical-fibre cables. Various “power over Ethernet” standards have been developed to reduce the effort involved in laying cables. The 802.3bu standard is the subject of much discussion at the moment. With this single-pair Ethernet (SPE) technology, signals and power are carried by just two conductors.
What does single-pair Ethernet mean?
This single-pair cable is also referred to as PoDL (Power over Data Line). Power outputs of up to around 15 watts can be carried with PoDL when matched to appropriate cross-sections and channel lengths. Here, the transfer distance can be up to 1,000 metres in length, with rates of between 10 Mbit/s and 1 Gbit/s. “Single-pair Ethernet is propelling the transformation of industrial networks forwards,” says Dr Oliver Kleineberg, Global CTO of Industrial Networking Solutions at Belden. “This technology saves space, weight and material costs, not to mention making it completely unnecessary to install separate cables for carrying power and data, as in the case of PoDL. The entire physical network becomes more permeable.