SEATTLE — At CES today the WiFi Alliance unveiled a new feature for the popular wireless networking standard: precision time synchronization. This feature, which the Alliance is calling Wi-Fi Certified TimeSync, is the ability to engage in sub-microsecond coordination of operations among multiple wireless devices. The "killer app" for this capability is expected to lie in the audio/video market, where it will allow multiple wireless audio/video devices, such as smart TVs and speaker systems, to remain in sync during media playback. But the technology holds promise for industrial, automotive, healthcare, and IoT applications, as well.
(Source: Wi-Fi Alliance)
"This capability allows tightly-coupled coordination of devices in many applications," Alliance VP of marketing Kevin Robinson told EE Times in a phone interview. In its primary audio/video application space, TimeSync will allow creation of Wi-Fi-connected speakers for wireless surround-sound systems that won't suffer from echo, drift, and sync issues that plague today's implementations. But other applications that require tightly-coupled coordination among devices will benefit from the capability as well. "It can be used to synchronize data collection, control operations, and coordinate event generation," Robinson said, " along with its audio/video applications. And it can happen across devices from various vendors."
In its explanatory materials on Wi-Fi TimeSync, the Alliance points out several industrial examples of this new feature. Distributed process control, for instance, can use TimeSync to synchronize the operation of motion-control systems in a production line so that all controllers work from the same clock. Similarly, widely-separated sensor systems can provide data collected to the same time base, simplifying analysis and diagnostics.
The synchronization feature relies on Wi-Fi's existing timing measurement functions, Robinson explained, covered in the upcoming IEEE 802.11mc standard. "The main concept," he said, "is figuring out the round-trip time between devices. A master clock unit sets the standard; then other units calculate an offset. It's not unlike Ethernet synchronization, but is done with better granularity." The timing measurement is generally implemented in hardware, he added, so the chipset used in a design has to support Wi-Fi timing measurement. The synchronization can occur between devices and an access point, or between devices using WiFi Direct.
—Rich Quinnell covers industrial control for EE Times. Contact him at firstname.lastname@example.org,