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17 June 2019

Dialog tries to convince skeptics that WiFi can beat low power rivals

Dialog Semiconductor has unveiled its new FC9000 family of WiFi SoCs, a family that it says can replace the likes of Z-Wave, Zigbee, and Bluetooth. It claims that its fancy new power management algorithms allow for sufficient battery life, while removing the need for “cumbersome” gateways between these other protocols and the Internet.

Now, the gateway claim has some merit, but we do take issue that “typically supporting a battery power lifetime greater than one year” is not exactly the deathblow that we were expecting based on the pitch. Aimed at devices like connected door locks, video monitoring systems, and connected thermostats, the question for the FC9000 family is whether the one-year life is enough, or does it remain too high a burden for the user experience.

It is well established that consumers don’t like changing the batteries in their devices. It is also true that Z-Wave, Zigbee, and Bluetooth don’t have enough bandwidth to manage the data-intensive requirements of the aforementioned devices. So then, positioning the new chips as a solution to these other personal area network (PAN) protocols is a little disingenuous, as they were never really rival candidates. Sure, improved power consumption is a boon for WiFi, but these device types were hardly on the verge of jumping ship to Z-Wave – rather, they’d be considering how to pitch a wired connection for power to the consumer.

Instead, we’re more interested in the “wireless sensors” that Dialog mentions, which don’t fit in with the other device types. These sensors are rivals for the low power PANs, but as there is no mention of how the FC9000 SoC compares to a specific rival approach, and so the value proposition isn’t particularly clear.

The argument here will be that even if WiFi isn’t as long-lasting as Zigbee, the cost of bundling the required gateway into the end-product is more of a burden than a lower battery life in the WiFi-powered sensor. The pitch is that a WiFi-enabled sensor kit, of say three sensors to cover a home, is a better value offering than a three-piece Zigbee or Z-Wave offering and the required gateway – even if the battery life of the WiFi unit is lower.

On a pure cost basis, if the WiFi sensor could get three years out of a coin-cell (we’re in napkin-math hypothetical territory here, unfortunately), then the battery replacements  for these sensors over a 10-year period (the conventional yardstick) will be lower than the cost of the Zigbee or Z-Wave gateway. The trade-off is the effort and hassle of having to replace these batteries in the end device, but that’s something that the marketing department have to worry about.

However, Bluetooth’s new offerings make some pretty big claims about battery life, and as every smartphone has Bluetooth, that could be a spanner in the works for this WiFi-led vision of the future. As there are likely two smartphones in any given smart home, the burden here is setting up the application integrations to make these smartphones function as gateways for these wireless sensors, which in the WiFi approach could be handled by the push of the WPS button on the router – much more streamlined, but still requiring some manner of account pairing with the smart home, which is again likely going to involve a smartphone somewhere.

So then, this is a bit of a messy proposition. Given the expected scale of the market, there’s plenty of room for Dialog’s vision of the future, and thankfully the company is not proclaiming WiFi as the only protocol needed for the smart home. Dialog has plenty of Bluetooth offerings too, and it hasn’t nailed its colors to the mast.

Dialog says that the FC9000 SoC is the first new WiFi product since Dialog acquired the mobile communication assets of Silicon Motion, a deal that was officially closed last week. Dialog cites its proprietary power-saving algorithms, which it says allows the device to operate on just a few microamps (µA, millionth of an amp).

A hardware-accelerated encryption engine is also on hand, which should open up more advanced security functions than what is typically possible on the low power PAN chipsets. Dialog says that you can run the device’s application code on the FC9000, but you could pair it with another microcontroller if desired. The system-on-chip is available today, and you can also buy it as an integrated module.

Like many of the technical details, Dialog isn’t talking about the price in its announcement. From the product page, you will learn that the 7mm x 7mm package is based around an ARM Cortex-M0+ core, with 1.6MB of SRAM. There are a lot of I/O options available, and the WiFi PHY supports 802.11b/g/n. That provides a maximum throughput of 72Mbps. The data sheet goes into a bit more detail, but not regarding battery life.

Dialog points to Venstar as its first customer, an energy management and thermostat supplier that is using the new SoC. Venstar CEO Steve Dushane said: “Thanks to Dialog’s new SoC, our customers are enjoying a more efficient, reliable WiFi sensor and over a year of battery life. Being first to market with this technology is giving us a significant competitive advantage.”

“The FC9000, the first product in our new VirtualZero product line, complements our existing portfolio of leading Bluetooth low energy SoCs for connected devices and represents our next IoT connectivity innovation to pass on to our customers,” said Sean McGrath, GM of Dialog’s connectivity and audio business group. “This WiFi device is the first in a series that we plan to launch which solves major pain points for both manufacturers and end users around IoT network compatibility and power consumption.”