IoT protocols: which to choose and why

WiFi

Uses your existing WiFi and offers plenty of bandwidth, but uses more power. Good for cameras and mains-powered devices; impractical for battery sensors. Many cheap WiFi devices depend on the manufacturer's cloud.

Zigbee

A low-power mesh protocol: mains-powered devices repeat the signal and extend coverage. Widely used for sensors, bulbs and switches. It needs a hub or coordinator.

Z-Wave

Also a low-power mesh, but on a frequency band below 1 GHz, with less interference from WiFi and good penetration through walls. Devices are usually certified to work across brands.

Thread and Matter

Thread is a low-power, IP-based mesh network. Matter is an application standard backed by the major manufacturers to make devices compatible across ecosystems; it runs over Thread, WiFi or Ethernet. It's promising, but it's worth checking which specific features each device supports.

Bluetooth LE

Short range and very low power. Common in locks, nearby sensors and initial device setup.

LoRaWAN

Long range, up to several kilometres in good conditions, with minimal power use and small amounts of data. Ideal for spread-out sensors: car parks, tanks, meters or large buildings.

And KNX

KNX is the professional building automation standard, usually wired. It's the backbone for critical functions, and a gateway lets you bring IoT devices from other protocols into it.

How to choose

• Battery powered? Zigbee, Z-Wave, Thread or LoRaWAN.
• Far away or spread out? LoRaWAN or a well-planned mesh.
• Critical function? Wired or KNX as the backbone.
• Want independence from the cloud? Protocols with local control and your own platform.