Thread is a protocol designed to connect smart home devices in a wireless mesh network. It works much like Wi-Fi but requires less power. With Thread, devices from any manufacturer can create a separate low-latency mesh and share encrypted data. Thread enables supported devices to connect and speak to each other without any configuration or management on your part, and it works locally without going back and forth to the cloud.
You can use various application layers on top of Thread, including Matter. I go into more detail about the unifying smart home standard in my Matter guide. If you're setting up a smart home, you'll likely run into terms like “Thread” and “Matter” now that the technologies are baked into more and more products. Here's what you need to know.
What Is Thread?
Thread is a way for smart home gadgets to connect and share data. It is a low-power, low-latency, low-bandwidth alternative to Wi-Fi. Thread is especially important for small gadgets like water leak detectors, motion sensors, smart locks, smart shades, and smart bulbs. Think devices that only need to connect intermittently and have limited power and bandwidth needs.
Based on the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 radio technology on the 2.4-GHz spectrum, Thread is designed to connect low-power devices to a Wireless Personal Area Network (WPAN). Thread works in much the same way as Wi-Fi and Bluetooth (Wi-Fi is IEEE 802.11 and Bluetooth is IEEE 802.15.1). Several protocols are based on the same IEEE 802.15.4 tech, including Zigbee, WirelessHART, MiWi, and a few others.
Pros of Thread
Low power requirements (far lower than Wi-Fi)
Low latency for fast response times
Self-healing network (you can drop and add devices easily without breaking the network)
No proprietary hub required (though you do need a Thread Border Router to connect the Thread mesh to Wi-Fi)
Very scalable and can handle hundreds of device connections
Supports AES-128 encryption and password-based authentication
IPv6 (Internet Protocol version 6) support for direct device addressability using IP addresses
Cons of Thread
High-bandwidth devices (security cameras) can't use it
Support for the latest version is limited, so the current landscape is fragmented
The range and number of devices that can connect are still limited
Old Thread devices can't always be updated to new versions
A Thread Border Router is required to connect to the internet and cloud services
Thread Border Routers
Photograph: Simon Hill
While Thread enables supported devices to form a mesh, you need a Thread Border Router to connect that mesh to your Wi-Fi, Ethernet, or any other home network. Without this connection, the Thread mesh is closed and cannot connect to the internet. Most Thread Border Routers are also Matter controllers, and you have multiple Thread Border Routers in your setup. Here are some of your options: