Also known as: Sigfox, UNB network, 0G network
Sigfox is an ultra-narrowband (UNB) low-power wide-area network for the Internet of Things, designed to carry very small messages over long distances at minimal power and cost.1 Its defining trick is extreme spectral thrift: each uplink occupies only about 100 Hz of a sub-GHz ISM band, so a receiver’s noise bandwidth is tiny and the link budget is generous. Sigfox is often marketed as a “0G” network, deliberately positioned below cellular data.
Overview
A Sigfox device has no network to join and no channel to request. It simply transmits a short message on a randomly chosen frequency, then repeats it (by default three times) on different frequencies at different times. Base stations continuously scan the whole band, and the back end reconciles the copies. This unslotted, cooperative-reception model keeps the endpoint radio extraordinarily simple and cheap.
Technical characteristics
| Property | Value |
|---|---|
| Uplink | DBPSK, ~100 bps, ~100 Hz channel |
| Downlink | GFSK, ~600 bps |
| Payload | Up to 12 bytes uplink, 8 bytes downlink |
| Duty limits | ~140 uplink and 4 downlink messages per device per day |
| Bands | Sub-GHz ISM per region (868 MHz EU, 902 MHz US, …) |
| Diversity | Time + frequency (repeated transmissions) |
The tiny payload and daily message cap suit metering, alarms, and status pings rather than streaming — a single Sigfox device can run for years on a small battery.
History
Sigfox was founded in France in 2010 and built out national UNB networks across Europe and beyond under a single-operator model.2 After financial restructuring, the technology and network assets were acquired by UnaBiz in 2022, which continues to operate and evolve the standard.
Deployment
Sigfox targets massive, ultra-low-cost sensor fleets: utility sub-metering, logistics tracking, environmental monitoring, and simple alarms. It competes with unlicensed LoRaWAN and licensed cellular LPWANs such as NB-IoT; the trade is Sigfox’s simplicity and battery life against its strict message limits and dependence on one operator’s coverage.
Decoding it with GopherTrunk
Sigfox is out of scope for GopherTrunk, which decodes trunked land-mobile voice, not IoT telemetry. Its ~100 Hz uplinks are so narrow they are hard to even spot on a normal waterfall, and the network’s device provisioning and back end are proprietary. GopherTrunk implements neither the UNB PHY nor the Sigfox cloud protocol.