SigFox
SigFox is a concept for wireless low range WANs(LoRaWAN) developed by the French company of the same name. Similar concepts are nWave, Ingenu, the Thread network, IEEE 802.11ah or ZigBee 3.0. The SigFox network concept, which works completely independently of existing networks, targets applications in the Internet of Things( IoT) and Machine to Machine Communication( M2M).
The SigFox concept, also referred to as the 0G network, is designed to transmit short status messages of sensor and position data. It stands for a bidirectional end-to-end connection, comparable to a transparent transport channel that starts at the certified SigFox modem and ends at the web-based application. The configuration data and the end device and sensor messages are transmitted to the IT system via this transport channel. On the cloud side, a web API takes care of end-device management as well as configuration and data integration. The application programming interface (API) is based on HTTPS and the JSON format, JavaScript Object Notation (JSON).
As far as transmission security is concerned, communication is secured in many ways, including messagescrambling and protection against replay attacks. In addition, only the end device manufacturers control and understand the data exchange between the end components and the IT system, since the connection secured by SigFox starts with the modem.
In terms of radio technology, SigFox operates in the sub- gigahertz range at 868 MHz( EU) or 902 MHz (USA). Eight channels with a bandwidth of 25 kHz are transmitted in the available overlay bandwidth of 200 kHz. To avoid radio interruptions, SigFox uses the frequency hopping method. Transmission is based on ultra-narrowband, which serves scalability and underlines the advantage of low power consumption. Data rates are 100 bit/s or 600 bit/s, also contributing to energy savings. The sensors are expected to transmit no more than 140 messages per day with a maximum payload of 12 bytes. In bidirectional operation, in which Sigfox radio nodes can also receive messages, the message length has been set to 8 bytes. This allows radio nodes to trigger actions in and manage IoT devices.
In terms of power consumption, SigFox modems require between 20 mA and 50 mA in active mode, and close to zero in inactive sleep mode. The radio node itself initiates the factive unk transmission, which may take a maximum of 25 s. These low power values mean that battery-powered edge devices have a battery life of up to ten years.