3 Problems to Solve Before Plants Can Benefit from 5G-TSN Integration
Smart manufacturing is in full swing, ready to hit critical mass—but industrial plants have some work to do to prepare for this transformation.
According to Deloitte, 86% of manufacturers believe that smart-manufacturing initiatives will drive industry competitiveness in the next five years; 83% think these initiatives will change the way products are made.
Meanwhile, however, only 5% of manufacturers have a full-on smart manufacturing plant in operation, and only 30% have smart-factory initiatives underway.
5G-TSN integration: critical along the road to smart manufacturing
In a recent blog, we explained the potential for 5G to bring the real-time capabilities of TSN (time-sensitive networking) to wireless networks to support industrial communication.
TSN introduces mechanisms for Quality of Service, reliability and configuration, allowing different kinds of data traffic to share the same network while ensuring reliable throughput within a specific amount of time.
The unification of 5G and TSN could create new opportunities for fully connected and more productive industrial environments, enabling visibility into plant operations and pinpointing opportunities for improvement so managers and employees can work smarter and make better decisions.
While 5G possesses the capabilities required to work with TSN, and standards organization 3GPP has made substantial strides toward integrating 5G systems with TSN, obstacles still stand in the way of making it reality.
There are three major challenges for the industry to overcome before industrial automation can benefit from 5G-TSN integration. Let’s take a closer look.
1. Data communication across OSI layers
Industrial communication operates through Ethernet protocols within Layer 2 of the OSI model. Meanwhile, IP-based communication is found in Layer 3.
For industrial networks, both kinds of addressing are equally important. Typically, industrial protocols use Layer 2 addressing for communication between PLCs and sensors or actuators. SCADA and monitoring applications use Layer 3 addressing.
To enable the forwarding of Layer 2 and Layer 3 communication through a 5G network, 3GPP developed two types of protocol data units (PDU) and user plane functions (UPF): Ethernet and IP. Simplified, the user equipment decides, based on the headers in the packet, whether the 5G system should handle the packet as a switch (for Ethernet) or as a router (for IP) communication.
But today’s industrial 5G core systems don’t support this differentiation in communication. They only support IP communication. Consider a traditional switch. This device “learns” where the Layer 2 addresses are. When the switch receives data packets, it knows where to put them. The 5G system behaves as a router. When it receives Layer 2 communication, it essentially tosses the information aside instead of passing it along like it should. It doesn’t know what to do with Layer 2 communication. 5G can’t currently support data communication across layers.
2. Lack of time synchronization
To automate workflows, ensure quality and prevent equipment failure, industrial networks or network segments require synchronization to support successful operation control loops. For example, a control loop enables a PLC to control a wireless robotic arm, or multiple sensors to report their data to the cloud, with time-synchronization enabling a consistent sequence of events.
Time protocols, such as PTP (precision time protocol), are required to manage a control loop or sequence of events. But neither IEEE 1588 (PTP) nor IEEE 802.1AS are currently supported over 5G.
To integrate 5G systems into industrial automation applications, 3GPP offers possibilities to implement time synchronization (e.g., through SIB9 messages). Although they’re defined in the standards, these features haven’t trickled down into products for industrial networks yet.
3. Quality of service capabilities
In a traditional Ethernet LAN, all data coming from devices is treated similarly. But in industrial and control networks, QoS is needed to control and manage traffic, ensure proper performance of mission-critical applications, and minimize interference like latency, packet loss and jitter. This differentiation of traffic types guarantees data delivery and service.
Because the 3GPP-defined features to enable QoS are not yet available in 5G core systems for industrial networks, all traffic originating from one end device is treated with the same priority. This lack of QoS during 5G data transmission creates performance issues that can lead to consequences such as application time-out.
5G-TSN solutions are on the way
Belden is working to develop an architecture that will help industrial environments take the first steps toward 5G-TSN integration so that, when the time comes, they’ll be ready to take advantage of the opportunities it offers in a cost-effective way.
Our solutions will help manufacturing plants build the future by integrating 5G and TSN for seamless wired and wireless integration.
In future blogs, we’ll share more about what these solutions look like, and how they’re helping industrial environments prepare for what’s to come in digital transformation.
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About the Author
Lukas Bechtel has been with Belden since 2012, rising through the ranks from test automation engineer to technology architect in our CTO office. He’s also a faculty member and researcher at Esslingen University, where he teaches students about IT and network security and industrial networks while studying areas like Industry 4.0, wireless communication and industrial communication and security.