Zigbee Technology
Zigbee. That short-range mesh thing people keep confusing with Bluetooth. It runs on 802.15.4, acts like it knows what it’s doing, and tries to glue smart home devices together without screaming. Low power, low data rate, decent range – in theory. Not LPWAN. Not Wi-Fi. Just somewhere awkward in between.
Vendor and URL
This circus is run by:
Main vendor: Connectivity Standards Alliance (CSA), formerly Zigbee Alliance
Official docs: https://csa-iot.org
If the link’s dead, Zigbee probably is too. Good luck.
Technical Public Documentation
The docs are out there. Some are paywalled. Some are PDFs that hate your soul.
Full spec: Zigbee Spec at CSA
GitHub repo: https://github.com/zigpy (for those who like open Zigbee stacks)
Read before asking dumb questions. Or don’t. Your call.
Overview
Zigbee builds a self-healing mesh network over 2.4 GHz. Devices talk to each other. Some relay. Some sleep. It’s used in smart homes, sensors, and the occasional haunted light bulb. Works better when you don’t move anything. Or touch it. Or breathe near it.
Architecture
One coordinator runs the show. Routers extend the mesh. End devices hang off them like digital barnacles. Mesh topology is the name of the game – packets bounce from node to node like drunk homing pigeons. There's no cloud unless you bolt one on.
Device Roles
The coordinator is king – only one per network. Routers do the legwork, passing messages along. End devices? Sleepy, low-power slackers that only wake up when something pokes them. Everyone has a job. Nobody’s paid.
Channelization
Operates on 16 channels in the 2.4 GHz band. Shares space with Wi-Fi and microwave ovens. Fixed channels, chosen during network creation. Pick the wrong one and suffer interference purgatory. Channel agility? Nah. Too modern.
Frames
Zigbee frames ride on top of 802.15.4. Expect MAC headers, NWK headers, APS headers, and maybe some payload if there's room left. Fragmentation exists. Compression is spotty. CRC at the link layer – if anyone cares. Some parts are readable. Others are obfuscated just to mess with you.
Networking
Peer-to-peer-ish via mesh. But only within the network. Devices must be joined properly – no random freeloaders allowed. IPv6? Nope. That’s what Thread is for. Zigbee speaks Zigbee, and that’s that. Addressing is done with 16-bit short addresses and a big ol’ table of who’s who.
Security
AES-128 encryption is there. Sometimes even used correctly. Devices have link keys, network keys, and maybe a pre-shared master key. Joining can be secure – or wide open, depending on your setup. If you left your coordinator in pairing mode for 3 weeks… yeah, that’s on you.
Networking Process
Power on. Search for the coordinator. Ask to join. Get accepted (or not). If you’re in, you get a short address and some network keys. Then it’s transmit, sleep, repeat – unless you’re a router, then you never sleep. Sorry.
Use Cases
Zigbee is in smart lights, smart plugs, door sensors, motion detectors, thermostats, and those weird voice assistant bridges. Also shows up in industrial gear – quietly doing its job in warehouses and greenhouses. If your fridge can talk to your lightbulb, it’s probably Zigbee. Or it’s possessed.