A closer look at SigFox: Supercharging the smart city and beyond

A closer look at SigFox: Supercharging the smart city and beyond

Introduction and significance of SigFox

The reach of the Internet of Things (IoT) knows no bounds, but as we shift towards a scenario where every device is online, the technology begins to blur.

In theory, it sounds like a great idea to get wind turbines, smart bins, oil pumps and electricity meters online, and in doing so add a ‘smart’ dimension to buildings, grids, streets, hospitals, agriculture and factories. Having all of these devices (and more) capable of sending back information on their whereabouts and their status is what the Industrial Internet of Things (IIoT) is all about. However, Wi-Fi and Bluetooth won’t work over large areas of cities and countryside, while using the mobile phone network means big batteries and big bandwidth. The former is impractical and the latter not required.

What we need is a low energy, narrow bandwidth technology that will let millions upon millions of devices occasionally send small packets of data to a central server. In the search for a long low-range radio communication solution, French startup SigFox has been getting the big players of the Internet of Things very excited.

Ludovic Le Moan, CEO of SigFox

What is SigFox for?

In the IIoT, cellular networks cannot always be relied on. If a sensor or device is away from electricity, cellular radios are far too power-hungry to be efficient – the regular maintenance needed on hundreds or thousands of devices spread over huge areas would be ridiculous.

The answer is a low-power mesh technology, and it’s one from French startup SigFox that’s catching the industry’s attention. An ultra-narrowband technology that promises lower cost, two-way transmission of small packets of data, SigFox is perfect for connecting devices in different locations and across vast areas. SigFox’s radio frequency (RF) network provides ranges greater than cellular networks, but with a very low power requirement.

Tiny sensors on oil pumps

How significant is SigFox?

«We are very excited about SigFox – they get it,» says Nav Dhunay, CEO and founder of Ambyint, an IIoT solution for optimising oil production. «The solution they are implementing is exactly what the industrial space needs. To make wireless sensors truly wireless we need them to be autonomously powered, such as by battery or solar,» says Dhunay. «As a result the overall power consumption of the sensor must be minimised – cellular networks are ubiquitous and easy to work with, but the cellular radios have a significant power requirement.»

Some think that SigFox is potentially a huge deal for the smart city. «The idea that we can create devices that use standard radio bands to communicate without intervention means we can think on a much bigger scale than indoors, or over managed areas,» says Mike Crooks, head of Mubaloo Innovation Lab. «We’re already seeing how these deployments can make a massive difference, such as in the case of Bigbelly, who are using a similar platform to deliver many services via their smart bins in many major cities across the world.»

Bigbelly smart bins let the authorities know when they need emptying

Bigbelly’s solar-powered smart bins, which intermittently compress their contents then alert the authorities when they need emptying, are now widely used by city councils across Europe and North America.

However, the technology is not just limited to smart cities. «Remote sensors can benefit from this technology, too,» says Crooks. «For example, think of the information we could gather from wind farms, tidal energy generation, or any other remote deployment.» The same goes for machinery in remote plants, any kind of corporate assets, and any mobile equipment.

Support and rival tech

Who is supporting SigFox?

Only Samsung Electronics. If an acceptance by device makers is paramount, SigFox hit the jackpot when the South Korean giant both invested in the company and then included the tech in its new IoT platform, ARTIK.

That’s not all – South Korea’s SK Telecom and Japan’s NTT Docomo are also investors, suggesting SigFox could have a big future in Asia, which is slated to quickly become the HQ of the IIoT, both in terms of ‘smart’ manufacturing plants, and in the production of IIoT sensors and electronics. However, it’s Europe that’s kicking-off SigFox, whose network already exists in the UK, France, Luxembourg, the Netherlands, Spain, Portugal, Belgium and Denmark.

Does it have limitations?

Capable of transmitting just 100 bits per second and a maximum of 140 messages per object per day at no more than 12 bytes each, SigFox is not for bandwidth-hungry, ‘chatty’ devices, just those that need to send back occasional data. «Certainly there are limitations with the SigFox solution, particularly around bandwidth, but with a properly designed IoT infrastructure you really shouldn’t have a high bandwidth requirement,» says Dhunay.

However, the technical limitations of SigFox means it will remain a technology for niche uses only. «Radio frequency has specialised use cases, with limited bandwidth, and without investment in the underlying infrastructure, coverage is likely to remain limited to metro areas,» says Phil Williams, Principal Architect, Rackspace. «Even then, with an expectation of billions of connected devices, congestion would likely become a factor.»

Although in rural areas SigFox messages can travel 1,000km, though urban areas that drops to single figures. Using the ultra-narrow band radio technology to connect devices to its global network, SigFox is one-directional, and doesn’t offer a platform or any kind of managed service – it’s just a connectivity technology. That’s why it’s been quick to market, and that’s why it’s been the first such technology to gain wide recognition in the industry. But there is a rival.

Flashnet's new 'smart city' inteliLIGHT controller

The rival: Actility

SigFox isn’t the only French technology vying to be a staple of the IIoT. Financed by Foxconn, Orange, KPN and Swisscom, Actility’s network for large-scale industrial IoT deployments is based on the Long Range Wide Area Network (LoRaWAN) approach. Although both Actility and SigFox are using the license-free, industrial, scientific and medical radio bands, the networks and business models are subtly different.

LoRaWAN is bi-directional and uses adaptive data rate (ADR) so that sensors will automatically communicate at the highest possible data rates after talking to Actility’s LoRaWAN network server. «A water meter can therefore move up to 50 kbps, and therefore spend much less time on air when sending a meter measurement, and quickly go back into idle mode, thereby saving significantly on battery life,» says Olivier Hersent, the CEO, CTO and Founder of Actility. Compare that to SigFox’s 100 bits per second maximum speed. «A SigFox sensor does not support such an adaptive data rate mechanism, and will always transmit at 100 bits per second, using more energy in transmitting the same data.»

It’s also worth noting that while Actility’s LoRaWAN is an open approach, SigFox isn’t. «SigFox has opted to quickly build a proprietary network, making it less flexible and able to adapt to the rapidly developing IoT market,» says Hersent. The business models differ, too, with SigFox in competition with network operators while Actility supplies operators with an all-in-one, cloud-based service called ThingPark.

Samsung's IoT platform ARTIK supports SigFox

Which of these scalable, low-energy and high-capacity technologies will ultimately triumph is anyone’s guess, but with M2M, smart city, sensor network and industrial automation applications on the rise – and expected to account for most of the 38.5 billion connected devices by 2020 – the smart money will be in close contact with both.