SigFox Technology

SigFox. The "send-it-and-pray" network. Ultra-narrowband LPWAN for when you want to whisper 12 bytes across the continent. Long range, ultra-low power, but don’t expect a conversation – it’s mostly one-way. It’s here to let sensors check in once a day and maybe live forever on a coin cell.

Vendor and URL

This little miracle is sold by:
Main vendor: Sigfox SA (or whoever bought them this week)
Official docs: https://build.sigfox.com
If the link’s dead, they probably restructured. Again.

Technical Public Documentation

They have docs. Some are pretty. Others are PDF fossils from 2016.
Full spec: Sigfox Radio Specs
GitHub repo: https://github.com/sigfox (not much there, but still something)
Documentation level: enough to get started, not enough to stay sane.

Overview

SigFox is built for dumb sensors that send tiny data over long distances. You get 140 uplinks per day. Downlinks? Only 4. Yes, four. Per. Day. It works if you treat it like a pigeon post system with network APIs.

Architecture

It’s centralized. Devices talk to base stations. Base stations forward to SigFox cloud. No peer-to-peer, no mesh, no drama. Just "send and forget." Works if the network exists where your device is. If not? Well, sucks to be you.

Device Roles

One role: transmitter. Devices send data. That’s it. No routers. No sleepy coordinators. Just silent warriors throwing bits into the void. The cloud handles the rest – assuming it catches your packet.

Channelization

SigFox uses ultra-narrowband around 868 MHz (EU) or 915 MHz (US). The idea is: stay quiet, be tiny, don't interfere. Channels? Predefined. Your device doesn’t pick – it just transmits. The network decides the rest.

Frames

Uplink: 12 bytes max. Downlink: 8 bytes. Frame format? Proprietary-ish. You don’t see much unless you dig or partner up. CRC? Maybe. Depends on the hardware and how lucky you feel.

Networking

No mesh. No neighbor discovery. No routing tables. Just point-to-cloud. Devices don’t talk to each other. They broadcast and hope a base station hears them. The backend handles deduplication if more than one picks it up.

Security

SigFox does encryption – kind of. Uplink frames are authenticated with a message authentication code. AES-based encryption is optional and mostly backend-driven. Key management? Managed by the platform. You just pay and pray.

Networking Process

Device powers on. Sends a message. That’s it. No handshake. No fancy pairing. You register the device ID in the backend, and it goes live. Downlink? Must be triggered by an uplink. Good luck syncing anything real-time.

Use Cases

Perfect for ultra-low bandwidth stuff: water meters, bike trackers, trash bins, parking sensors. Cows? Sure, if they’re polite. Industrial monitoring, theft recovery, and any use case where data can wait. Not for chatty devices. Definitely not for streaming anything except existential dread.