Sigfox is the world’s leading provider of connectivity for the Internet of Things (IoT). The company has built a global network to connect billions of devices to the Internet while consuming as little energy as possible, as simply as possible. Sigfox’s unique approach to device-to-cloud communications addresses the three greatest barriers to global IoT adoption: cost, energy consumption, and global scalability.
Sigfox rolled out the first global IoT network to listen to billions of objects broadcasting data, without the need to establish and maintain network connections. This unique approach in the world of wireless connectivity, where there is no signaling overhead, a compact and optimized protocol, and where objectsare not attached to the network. Sigfox offers a software based communications solution, where all thenetwork and computing complexity is managed in the Cloud, rather than on the devices. All that together, it drastically reduces energy consumption and costs of connected devices.
Ultra Narrow Band radio modulation
Using the Ultra Narrow Band modulation, Sigfox operate in the 200 kHz of the publicly available band to exchange radio messages over the air. Each message is 100 Hz wide and transferred at 100 or 600 bits per second a data rate, depending on the region. Hence, long distances can be achieved while being very robust against the noise.
SIGFOX has tailored a lightweight protocol to handle small messages. Less data to send means less energy consumption, hence longer battery life.
An uplink message has up to 12-bytes payload and takes an average 2s over the air to reach the base stations which monitors the spectrum looking for UNB signals to demodulate. For a 12-byte data payload, a Sigfox frame will use 26 bytes in total. The payload allowance in downlink messages is 8 bytes.
Star network architecture
A device is not attached to a specific base station unlike cellular protocols. The broadcasted message is received by any base station in the range, which is 3 in average.
Design choices and benefits
Sigfox has designed its technology and network to meet the requirements of mass IoT applications; long device battery life-cycle, low device cost, low connectivity fee, high network capacity, and long range.
The high quality of service of the Sigfox network relies on spatial diversity coupled with the time and frequency diversity of the radio frame repetitions.