Avnu Alliance demonstrates Time Sensitive Networking
Time Sensitive Networking (TSN) capabilities have been successfully demonstrated over wireless links by the Avnu Alliance, showcasing a new era of precision, safety, and efficiency for businesses employing robotic control and industrial automation. The TSN capabilities tested, namely time synchronisation (802.1AS) and traffic shaping (802.1Qbv), affirm the broad-ranging benefits TSN could bring to real-life industrial automation applications, particularly ones where time and safety are paramount.
Testing revealed a marked improvement in the operation of a remote-controlled robotic arm performing intricate manipulation tasks, even in the face of competing traffic, when these TSN capabilities were activated. This highlights the propensity towards enhanced precision and efficiency in such practical applications. Another significant finding from the tests was that wireless TSN ensured high priority traffic enjoyed low latency, resulting in faster response times and safer operations.
These TSN capabilities not only had implications for industrial automation applications but also proved effective for ProAV applications; such as audio and video streaming. Tests indicated that without the 802.1Qbv capability, the robotic arm's task was considerably interfered with by competing traffic, however, upon enabling TSN, the arm successfully completed the task amidst competing traffic.
Observations from the Avnu Alliance members showed that the robot control actuation and gripper status was reliably delivered over the wireless link, with most actuation commands arriving within 2 milliseconds of the previous sample. Avnu Alliance President and Chair of the Wireless TSN Working Group, Dave Cavalcanti, stated that these findings "validate capabilities such as time synchronization and bounded latency," clearly demonstrating the potential of TSN over Wi-Fi for industrial and ProAV use cases.
Response times in industrial automation applications need to be near instantaneous, especially for critical safety data like Emergency-STOP signals. Tests using the 802.1Qbv traffic shaping capability to schedule a time-sensitive queue whilst closing other interfering queues, showcased that wireless TSN benefits high priority traffic with low latency; fast-tracking response times and bolstering automated operations' safety and efficiency.
ProAV applications, encompassing audio and video streaming, also require precise time synchronization and low latency communications for seamless user experiences. To validate Wi-Fi TSN's benefits and capabilities for these applications, a testbed was designed to stream audio from a P1 Talker to a Listener over Ethernet and Wi-Fi. The test found that the maximum offset introduced by the wireless link was approximately 4 microseconds.
To ensure comprehensive interoperability, the Avnu Wireless TSN Working Group is developing test specifications for TSN over Wi-Fi. Automated Wi-Fi compliance package by Keysight, based on the Avnu TSN test plans, will aid Avnu members and test houses to propel the TSN Wi-Fi ecosystem. Keysight's Network Test and Security Solutions group's Vice President and General Manager, Ram Periakaruppan, emphasized the importance of "standardizing test methodologies for TSN over Wi-Fi," for network devices' component-level compatibility.
The capabilities demonstrated are already being utilised at Avnu Plugfest events. Parallel efforts are also being made to extend these advancements to 5G systems. The complete methodology and results of these experiments can be found in the Wireless TSN: Tests and Use Cases Demonstration with Wi-Fi whitepaper.
