Time-Sensitive Networking for Real-Time Applications (.PDF Download)

Crafted by the Time-Sensitive Networking Task Group, the Time-Sensitive Networking (TSN) standard helps to deliver real-time information, from streaming multimedia to synchronizing power microgrids (Fig. 1). The group, originally called the Audio/Video Briding (AVB) Task Group, defines extensions to the 802.1Q virtual LAN (VLAN) standard, implementing very low latency and supporting high-availability applications.

TSN implements a time-division multiple-access (TDMA) scheme (Fig. 2) to define fixed-priority VLAN slots for transmission. The approach can be used with strict priority schedulers via IEEE 802.1Q, or new processing methods like the TSN IEEE 802.1Qbv time-aware traffic scheduler.

The approach requires cooperation at the hardware level with time-synchronized devices, including network switches. Time synchronization is usually maintained using the IEEE 1588 protocol (see “What’s Behind The IEEE 1588 Protocol?”). This cooperation is necessary to maintain synchronization and make sure the priority of critical data is maintained.