Weightless SIG shelves white spaces, but it has new internet-of-things spectrum in mind

When the Weightless Special Interest Group (SIG) formed in 2012, it hoped to build a new kind of network designed to host billions of industrial devices on the internet of things using the emerging white spaces spectrum. But the SIG now finds itself forced to re-evaluate that strategy.

Its goal of powering the internet of things remains the same, but it’s been forced to look for a new frequency band on which to to run it. White spaces — the unused frequencies in between TV broadcasts — haven’t gotten the go-ahead from global regulators to be used for data networking with the exception of the U.S., Weightless SIG CEO William Webb said.

“We hoped that there would be an opening up of white spaces around the world,” Webb told me in an interview. “That simply hasn’t happened.”

The Weightless SIG's network and device roadmap (source: Weightless SIG)

The Weightless SIG’s network and device roadmap is getting pushed back as it changes frequencies  (source: Weightless SIG)

That situation has forced the SIG to suspend its work on commercializing Weightless in white spaces and focus on a band that already has global backing for data networking: the 800 MHz and 900 MHz frequencies used around the world for industrial, medical and scientific uses as well as some commercial devices such as baby monitors and burglar alarms. In Europe, it sits at 868 MHz on the spectrum chart; in the U.S., it centers on 915 MHz.

The SIG’s membership — which includes several U.K. heavyweights like [company]ARM[/company] and [company]Cambridge Silicon Radio[/company] — is now preparing to create a new standard called Weightless-N for the new frequency band (as opposed to Weightless-W for white spaces). According to Webb, it will only take between three-to-six months to produce the standard and possibly even the first commercial devices since most of the standardization work was already completed under Weightless-W. The SIG is basically swapping out frequencies.

But Webb admits there will be some tradeoffs. Weightless-N simply can’t support the speeds of Weightless-W, meaning average data rates will drop from tens of kilobits per second to tens of bits per second.

To you and I, either speed may sound like a paltry amount, but Weightless was never intended to be a broadband technology. Rather, it’s designed to support the small-bore networking needs of sensors, meters and instruments that transmit small bits of information only intermittently over long distances and at extremely low power.

A Weightless white space module (source: Weightless SIG)

A Weightless white space module (source: Weightless SIG)

For example, Argon Design demonstrated how Weightless-linked sensors could be embedded into bridges, train tracks and roads across a city. The vast majority of the time, these sensors stay silent. They only transmit when they detect a structural change in the infrastructure they monitor, indicating they might need some attention from the public works department. The emergence of this new kind of all-pervasive internet of things will be one of key topics at Gigaom’s Structure Connect conference in San Francisco next month.

Weightless-N can still handle almost all of those applications, Webb said. It has enough bandwidth to transmit meter readings, sensor data and GPS coordinates. What it can’t do is transmit more involved data, such as a still photo from a remote security camera or an audio file from a microphone. Webb said the SIG is hoping that white spaces will be a more mature market when demand for those types of applications increases.

On the flip side, the 800 MHz and 900 MHz bands already have a very mature ecosystem. Not only are there many companies already making the necessary radios, there is a big installed base of devices already capable of connecting to a Weightless network after a software upgrade. The Weightless SIG, Webb said, will have no trouble reaching its three main requirements: radio modules under $2 in cost, range of up 5 km (3 miles) and battery life up to 10 years on a single charge.

But the Weightless SIG isn’t the first to have the idea of using these industrial bands for internet of things uses. ZigBee and Z-Wave both use those frequencies for short-range communications, while the Wi-Fi Alliance is using the IEEE 802.11ah standard to develop lower-power technologies for connected devices. French startup Sigfox has been building city-wide and in some cases country-spanning networks targeting the same industrial IoT market as Weightless.

Weightless can still stand apart, Webb said. Most of these competing technologies are focused on more consumer use cases such as the smart home. And those companies targeting the industrial internet are using proprietary technologies, Webb said. It’s the SIG’s hope that it can bring these companies under the same standard and even cooperate with other standards bodies like the Wi-Fi Alliance where it make sense, Webb said.