New-Tech Europe Magazine | February 2018

Optimized for M2M: Ready for interworking between machines with common data model like OPC UA across the entire factory. Thisconvergence isprovidedbyTime Sensitive Networking (TSN). TSN is a set of IEEE 802 sub-standards which, when implemented, enable deterministic communication over Ethernet networks while keeping the benefits of communication in best effort manner, on that same network. TSN introduces different traffic classes that share the same link. TSN network configuration reserves resources for streams with deterministic time characteristics. TSN, therefore, enables one common network to be implemented which supports multiple communication standards. This introduces several improvements over standard Ethernet. Standard Ethernet communication is not time aware; it distributes the data over the entire bandwidth of the link with packets queued in order for transmission. TSN implements time awareness with scheduled traffic at configured offsets in cyclic intervals. That follows a schedule that is distributed by a network configuration controller. Further TSN features introduce Filtering and Policing for TSN streams, seamless redundancy and supports cyclic data transmission while also providing pre-emption for higher priority packets. TSN is defined by a set of IEEE 802.1 standards which specify the implementation Figure 2). As of September 2017, four of these standards are adopted, while the remainder is still within the Task and Working Group stages.

Figure 1: Automation Pyramid with typical assignment of networks to hierarchies.

and OT networks. This convergence reduces the cost of implementing the network, significantly lowering the cost of ownership and operation. TSN Implementation Correctly implementingTSN requires a solution which can provide a low latency and deterministic response

These standards are implemented over Ethernet (IEEE 802.3 Physical layer) and support star, chain, ring and mixed topologies and they are not limited to a specific data rate. Industrial applications will use 100Mbit and 1Gbit data rates mainly. Therefore, TSN provides the convergence between the IT

Figure 2: IEEE TSN Standards.

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