feature article
Subscribe Now

IoT Connectivity on the Cheap

Sigfox Offers Global Wireless Network for Slow Devices

“Phone home.” – E.T., the extraterrestrial

Bigger, better, higher, faster. That’s the usual mantra for electronics innovation, where standing still is the same as running backwards. But there’s something to be said for slowing down and smelling the proverbial roses. It’s relaxing. And it’s cheap. 

Amid all the expensive and incessantly hyped build-out of 5G wireless networks (including some egregious mislabeling of older technology), there’s a company that’s quietly moving in the opposite direction. They’ve built a “0G” network that’s unapologetically slow, unsexy, and low-tech. It trades off high bandwidth for low cost and longer battery life. It’s the Newton’s Third Law of innovation: equal, but in the opposite direction. 

Sigfox has been around for ten years and has connected over 15 million IoT devices to the cloud during that time, with the adoption rate rising rapidly thanks the use of IoT Management Software. The company is essentially a wireless carrier, just like AT&T, Verizon, Vodaphone, Airtel, or any of the other familiar conglomerates. But, where those companies race to upgrade their networks and increase bandwidth (and thus, revenue), Sigfox is content to sit on the sidelines and quietly maintain its low-end network for slow IoT devices. 

How slow? Would you believe 100 bps? That’s not gigabits or megabits; it’s bits per second. That’s slightly faster than two tin cans and some string. You can almost see the data moving through the air. Messages are packetized, just like grown-up networks, but the payload is limited to just 12 bytes. And, you can transmit only a few such packets per day. Not recommended for Netflix. Or even email. 

The advantage of this retro medium is that it’s dirt cheap and dead reliable. How does $3 per year sound? That’s orders of magnitude cheaper than wireless plans for the latest smartphones, and it’s even cheaper than limited data-only plans for connected IoT devices, which typically run about $5/month. Sigfox’s limitations may be severe, but the price is certainly attractive. 

The company is able to offer such old-fashioned prices by relying on old-fashioned technology. It’s wireless, but it’s not cellular – more radio than cellphone. Its network uses the unlicensed 900-MHz ISM (industrial, scientific, medical) band, which is popular with all sorts of low-power equipment. But physics works on its side. Because of its comparatively long wavelength compared to cellular signals, ISM transmissions carry a long way in clear air. Sigfox says its base stations have a range of dozens of miles. The entire city of San Francisco, for example, is covered by just 17 Sigfox base stations, versus about 250 for Verizon’s 4G wireless network. 

The low speed and basic modulation scheme mean that RF silicon is cheap and plentiful, both for device designers and for Sigfox itself. Its custom base stations cost about $5K apiece to build; the big-name wireless carriers can add a few zeroes to that number. Sigfox rents space on the utility poles just like everyone else, and it pays carriage fees to second-tier MVNOs for access to backhaul bandwidth. But, because Sigfox and its customers use so little of that bandwidth, the company gets cheap rates. A week of Sigfox usage is about a second’s worth of YouTube. 

In a sense, Sigfox’s network is larger than those of the big wireless behemoths because it’s international. Instead of distinct regional or national networks, Sigfox’s coverage spans a lot of the globe, covering about 28% of the surface of the planet and over 1 billion of its inhabitants. And it’s a single radio standard: no region-specific hardware, no SIM cards, no roaming agreements, and no software tweaks are required whether your equipment sells in Napa, Naples, or Nepal. 

Turning a sow’s ear into a silk purse, Sigfox points out that devices using its network will probably enjoy much longer battery life compared to Wi-Fi, Bluetooth, or cellular connections. A basic 900-MHz transceiver doesn’t use much power in the first place, and the network’s draconian limitation on data rates means you won’t be transmitting much data and receiving even less. (The cheapest Sigfox subscription tier doesn’t permit receiving data at all.) The best way to save energy is to just keep quiet, and Sigfox imposes monk-like tranquility. 

Sigfox says its customers are using the network for “track and trace” applications, such as locating shipping containers or tracking lost goods. It’s also ideal for remote sensors that send updates every few minutes and don’t need a downlink. “It can tell you if your trash can is full or if the parking space is empty,” says Sigfox VP Ajay Rane. He also described a large delivery company that was mysteriously losing delivery carts until it noticed hundreds of them clustered in one location. An off-duty delivery driver had been selling the carts to a metal scrapyard. 

“We’re making IoT accessible,” says Rane. “Sometimes [network infrastructure] doesn’t need to be better. You just want to connect something and forget about it for ten years.” 

Sigfox’s low data rates, limited bandwidth, and optional bidirectionality mean that you can’t use it for remote firmware updates, but Rane sees that as an advantage, too. “Any two-way communication has to be initiated by the device; we can’t send an unsolicited message to anything on the network.” Point being, an evildoer can’t send out malware, partly because the device won’t be listening and partly because there isn’t enough data to send anything malicious. Customers that do need remote upgradability will sometimes equip their devices with a secondary radio for just that purpose, then shut it off after the update. 

What’s next for a company that has no ambitions to upgrade its network hardware? Increasing its customer base. “We’re at the knee of the hockey stick,” says Rane. They’ve built out the network, now they’re pivoting to build up the subscriber base. Utility meters are one target-rich environment. “We’ve got the world’s largest IoT ecosystem.” Now they just need to attract more low-tech high-tech users.

One thought on “IoT Connectivity on the Cheap”

Leave a Reply

featured blogs
Jan 21, 2022
Here are a few teasers for what you'll find in this week's round-up of CFD news and notes. How AI can be trained to identify more objects than are in its learning dataset. Will GPUs really... [[ Click on the title to access the full blog on the Cadence Community si...
Jan 20, 2022
High performance computing continues to expand & evolve; our team shares their 2022 HPC predictions including new HPC applications and processor architectures. The post The Future of High-Performance Computing (HPC): Key Predictions for 2022 appeared first on From Silico...
Jan 20, 2022
As Josh Wardle famously said about his creation: "It's not trying to do anything shady with your data or your eyeballs ... It's just a game that's fun.'...

featured video

Synopsys & Samtec: Successful 112G PAM-4 System Interoperability

Sponsored by Synopsys

This Supercomputing Conference demo shows a seamless interoperability between Synopsys' DesignWare 112G Ethernet PHY IP and Samtec's NovaRay IO and cable assembly. The demo shows excellent performance, BER at 1e-08 and total insertion loss of 37dB. Synopsys and Samtec are enabling the industry with a complete 112G PAM-4 system, which is essential for high-performance computing.

Click here for more information about DesignWare Ethernet IP Solutions

featured paper

How an SoM accelerates and simplifies processor-based designs

Sponsored by Texas Instruments

If you're comfortable working with integrated circuits that have four to 48 pins, building a custom printed circuit board (PCB) for a new product might make sense. But when your design is complex—think: processor with more than 300 pins, DDR memory, eMMC, complex physical layout, and all the electrical considerations that go with it—a simpler, lower-risk, off-the-shelf product is often a better solution. Discover the benefits of a system-on-module (SoM) for complex, high-pin-count PCB designs.

Click here to read more

featured chalk talk

Security Regulations Drive Requirements

Sponsored by Mouser Electronics and Silicon Labs

IoT Security certification schemes can be complex, but security identities and security certification inheritance can make this aspect of your IoT design quite a bit easier. In this episode of Chalk Talk, Amelia Dalton chats with Mike Dow from Silicon Labs about the current state of global security regulations, the difference between physical and logical attacks, and how Silicon Labs SoCs and modules can help you solve the security demands of your next design.

Click here for more information about Silicon Labs EFR32xG21B SoC & xGM210P Modules with Secure Vault