VDI Conference on „5G in Automation“
Follow-up report by Thomas Schildknecht, CEO Schildknecht AG
The VDI specialist conference “5G in der Automation” (in English: 5G in automation) took place at the beginning of July parallel to the “Automation 2019” congress in Baden-Baden. Over 2 days and by means of 17 lectures, experts exchanged information on the current status and future aspects of 5G.
An important topic block for the automation specialists dealt with the technical details of the parameters of the services uRLLC (ultra-reliable low-latency communication) and mMTC (massive machine type communication) as well as the possibility of setting up separate “campus networks”. To their great disappointment, the interested end users had to note that these services will not be defined until Release 16, expected in 2020. Only then can baseband manufacturers begin with the final specification of the associated chips! And it will take another 2-3 years before the first OEM modules that can be integrated come onto the market. The consequence: 5G solutions for automation devices will probably not be available until around 2023!
What we automators understand by “latency”
Another topic was around fundamental misunderstandings between mobile phone technology providers on the one hand and automation providers and end customers from factory automation on the other hand on the subject of “latency”. This term is used by mobile providers and network equipment providers to describe the transmission time of a data packet over 5G in campus networks with 1ms as the target value. For Automators, however, this same term has a different meaning – in connection with fieldbus transmissions e.g. via Profinet and/or in future via TSN – which leads to considerable misunderstandings! In fieldbus technology, “latency” is used as a term for the fieldbus update time! In wired real-time applications, this value (jitter) may only be a few microseconds (!) for synchronized drives; today, however, it is a few 100 microseconds for 5G! The frequency range that can be used by campus networks should use the TDD principle (a kind of half-duplex time slot method). For low target latencies, however, a half-duplex data link is counterproductive. The automation engineers still know the problem from Profibus, who also worked on half-duplex. In contrast, the successor Profinet, where transmission and reception can take place simultaneously, i.e. full duplex, was introduced. TDD might have the consequence that the latency time will still be some orders of magnitude above the targets.
In order to fully achieve the 5G parameters, further technologies such as beamforming, MIMI antennas or millimeter waves need to be developed, to name just a few examples. It is therefore to be expected that the real and required (!) performance of 5G will only be fully realized and operational in a few years! Until then, it will be the task of the automation engineers to identify those application cases for which 5G already offers sufficient performance from Release 15 and thus represents a suitable technology.
Private 5G Networks: Campus Networks
Setting up campus networks will be possible from September 2019 – upon application to the Federal Network Agency. The politicians have made a courageous decision for the industry: 100MHz bandwidth in the 3.7 – 3.8GHz band was reserved for industrial applications and not offered to mobile phone providers at the license auction! This allows companies to set up and operate their own base station with e.g. 4G LTE or 5G technology on their company premises and use it for their industrial processes: For example, for a kind of “Super Wireless Lan” for IIoT and AGV networking of mobile and autonomous conveyor vehicles. The technological challenge will then be whether safety-critical signals such as emergency stops can also be reliably transmitted via a campus network. Profisafe via Profinet or TSN will be suitable fieldbus technologies here. First experiments are running on a 4G campus network at the RWTH Aachen within the 5GANG research project. Schildknecht AG has successfully tunnelled Profisafe through Profinet at an Ericsson base station and reported about it in a lecture.
The parallel “Automation 2019” congress offered – due to the precisely coordinated lecture times – a good opportunity for further information and technical discussions and also for personal contacts during the joint evening event.