# Prototype of 5G Integrated with TSN for Edge-Controlled Mobile Robotics
## 5 Conclusions  
In this paper, a prototype 5G system integrated with a TSN network has been presented for a typical industrial mobile robotics use case. The prototype consists of a 5G URLLC test system and commercially available TSN switches. Different TSN protocols were integrated with the 5G system for deterministic over-the-air communication. The paper describes the architectural details and step-by-step analysis on jitter reduction mechanisms applied in the communication chain between the application hosted in a factory cloud and the mobile robot. The selected use case of a mobile robot will play an increasing role in manufacturing in the future to increase production flexibility by, e.g., introducing line-less production systems. It puts high requirements on communication with regard to low latency, high reliability and low jitter. The experimental validation took place in an industrial shopfloor environment. In the context of 5G system integration with TSN, these are the first measurements taken in such an environment.  
With the TSN standards used, the performance results of the prototype satisfies the requirements of the use case, enabling the wireless control of mobile robots. Time synchronization over the 5G system can be achieved at high precision; the time error introduced by synchronizing over the TSN network--and including the 5G system--wasobserved to be lower than 8 \(\upmu\)s with a mean value of below 3 \(\upmu\)s in our experimental validation over the test period of more than 6 h. On the industrial shopfloor, the 5G URLLC test system demonstrated time-critical communication performance; we observed an end-to-end latency over the TSN network and the 5G system that was below 0.8 ms with a 99.9% reliability. However, a jitter in the transmission over the 5G system in the order of 500 \(\upmu\)s was experienced, which is due to the characteristics of the 5G design and the wireless characteristics. We studied an end-to-end TSN configuration using TSN time scheduling according to IEEE 802.1 Qbv, where all network nodes are synchronized to a common reference clock. One key measurement result is that the jitter introduced by different entities in the communication path can be isolated and compensated in a TSN-based network, reducing the overall jitter end-to-end. In particular, by having an IEEE 802.1 Qbv-configured TSN bridge located after a node with relatively large jitter, the IEEE 802.1 Qbv-configured bridge can compress this jitter. In our experiments, we could reduce the end-to-end jitter over the TSN and 5G network from \(\approx\)370 to \(\approx\)0.9 \(\upmu\)s through IEEE 802.1 Qbv configuration in the network.  
From our test setup and validation, we conclude that 5G, and in particular when integrated with an industrial TSN network, is capable of supporting demanding industrial automation use cases. We have implemented and validated this for the example of cloud-controlled mobile robotics in an industrial shopfloor environment.  
Conceptualization and validation, P.K., J.A., M.H.J., P.B. and J.S.; methodology, software, formal analysis, and research, P.K., J.A., M.H.J., P.B. and J.S.; writing--original draft preparation, P.K., J.A., M.H.J. and J.S.; writing--review and editing, N.K. and A.G.; supervision, R.H.S. All authors have read and agreed to the published version of the manuscript.  
This work was performed in the framework of the \"5G-Comet\" project funded by the State of NRW through the Ministry of Economic Affairs, Innovation, Digitalization and Energy of the State of North Rhine-Westphalia with the funding code 005-2008-0093.  
The authors would like to acknowledge the support from their colleagues at Hirschmann, and [PERSON], [PERSON], [PERSON] from the testbed team at Ericsson business unit networks.  
The authors declare no conflict of interest.