What is Thread
Thread is an IPv6-based, low-power mesh networking technology for IoT products, intended to be secure and future-proof. The Thread protocol specification is available at no cost; however this requires agreement and continued adherence to an End-User License Agreement (EULA), which states that “Membership in Thread Group is necessary to implement, practice, and ship Thread technology and Thread Group specifications”. Membership of the Thread Group is subject to an annual membership fee except for the “Academic” tier.
Based on the universally-supported Internet Protocol (IP), Thread is built using open and proven standards. Thread offers efficient routing of data from device to device, covering large areas without the need for repeaters or additional bridging devices. It is application-agnostic and runs all IP-based building automation protocols, contrary to low-power solutions that only work with their own application library. It offers devices to communicate secure, end-to-end with endpoints across other IP-based link technologies, such as Wi-Fi, Ethernet, and Cellular. Due to these superiorities, it has been widely applied and brings a lot of benefits.
On the one hand, it brings a familiar way of setting up and managing the network for system administrators, with no need to worry about address and topology assignment. End-to-end routing and addressability allow IPv6 packets to securely move from one end point to the other, whether on the same Thread mesh network, or across the world. Its 6LowPAN foundation is based on low-power IEEE 802.15.4 radio technology that supports sleepy nodes and reduces network overhead. And by offering multiple application protocols, it seamlessly integrates with existing products. Thread is based on this proven, secure and already widely deployed Thread-specification that is currently in use for residential IoT applications.
On the other hand, it enables easy integration in the connected home. Being an IP-based open standard, it allows smart home devices to securely and reliably connect directly to the cloud. Home automation using IoT devices such as lights, thermostats, door locks, and security cameras provides a convenient and rewarding experience for consumers.
Google wireless Thread frequency range is based on the IEEE standard 802.15.4 wireless protocol. It is operating on one of three unlicensed ISM frequency bands:
- Thread protocol frequency in Europe is 868 MHz
- Thread protocol frequency is 915 MHz in North America
- The global Google Thread protocol frequency range is 2450 MHz
Thread 1.2 – 2020.05.12
Thread 1.1 – 2015.07.14
Thread Group – 2014.11.29
Like most wireless protocols, thread also use AES encryption to secure the safty of network.
Thread has outstanding features as follows:
Available now: The Thread Spec is available publicly; the Certification program and fast-ramp tools are available to members, and there are many Thread Certified Components to start development with now.
Built for IoT: Based on proven standards, Thread enables a low-energy footprint, secure and reliable connectivity with no single point of failure, interoperability, and scalability up to hundreds of nodes.
IP-based: Thread provides a convergence layer across all networks, provides device-to-device and device-to-cloud communication, and enables the flexibility to work with many and/or multiple application layer choices, and ecosystems.
Secure networks: Thread allows only authenticated nodes to join its network, provides user-friendly commissioning of devices to the network, includes built-in link layer security, and encrypts all network traffic.
Seamless integration: Thread extends the internet into low-power end devices, and uses border router(s) to expand to the internet and other networks such as Ethernet, Wi-Fi and Cellular.
Low power: Thread supports battery-operated devices as part of a home network. This allows the devices that people use every day – including thermostats, lighting controls, safety and security products – to be a part of the network without requiring constant charging or frequent battery changes.
- IPv6 based
- Low power
- Low-cost and proven hardware
- Simple network installation and easy operation
- Centralized commissioning and operation
- End-to-end enterprise-level security using certificates
- End-to-end routing and addressability
- Easy migration from traditional building automation towards true IP systems
- Increased room for devices for large managed networks
- Works independent of Internet connection
- Integration with enterprise IP networks
Device Type and Role
There are two types of Thread Devices defined by the specification: The Full Thread Device (FTD), and the Minimal Thread Device (MTD). The MTD has the lowest requirements for device hardware (e.g. memory size) and power consumption, while the FTD plays a wide range of roles in a Thread Network, which are further detailed in the sections below.
Routing Full Thread Devices
Thread Routers not only provide routing services for Thread Devices in the network, but also provide joining and security services for devices trying to join the network. They are not designed to sleep, but can downgrade their functionality and become REEDs (Router-eligible End Devices).
The Leader is an additional role of one Router in a Thread network. It is an elected role of one Router, which takes certain decisions in the Thread network such as allowing REEDs to upgrade to Routers. If the Leader of a Thread Network fails, another Router will be dynamically selected to resume the role, because all Routers have the required Thread Network Data to seamlessly assume this role.
Non-Routing Full Thread Devices
Router-Eligible End Device (REED)
REEDs have the capability to become Routers, but they are not acting as Routers due to the network topology or conditions. The Thread Network manages REEDs becoming Routers through the Leader, without user interaction.
Full End Device (FED)
FEDs are end devices like REEDs, however, they do not have the capability to become Routers, so will never become Routing Thread Devices or Leaders.
Non-Routing Minimal Thread Devices
Minimal End Device (MED)
Minimal End Devices (MEDs) communicate only through their Parent Router and cannot forward messages to other devices. A MED has its radio turned on, even when idle.
Sleepy End Device (SED)
Sleepy End Devices (SEDs) communicate only through their Parent Router and cannot forward messages to other devices. An SED has its radio turned off during idle periods and wakes periodically to communicate with its parent.
Synchronized Sleepy End Device (SSED)
Synchronized Sleepy End Devices (SSEDs) also communicate only through their Parent Router and cannot forward messages to other devices. An SSED has its radio turned off during idle periods and wakes periodically to listen for messages from its parent at scheduled intervals.
Bluetooth End Device (BED)
Bluetooth End Devices (BEDs) communicate only through their Parent Router, which is a Bluetooth LE Bridge Router and cannot forward messages to other devices. Unlike other Thread Devices, these communicate over a Bluetooth Low Energy Link, instead of IEEE 802.15.4.
A Border Router is a role of a Thread Device that provides connectivity from the Thread Network to adjacent networks on other physical layers (for example, Wi-Fi or Ethernet). There may be several Border Routers in one Thread Network. They provide services for devices within the Thread Network, including routing services for off-network operations. In addition, any FTD can provide Border Router services, even if it is not acting as a Router in the Thread Network.
Look for products bearing the “Built on Thread” or “Thread Certified Component” logos. These devices have undergone and passed rigorous Thread network testing and certification.
OpenThread released by Nest is an open-source implementation of Thread technology, based on the draft Thread 1.1 specification. Developers who choose to implement OpenThread in shippable products must join the Thread Group in order to certify those products and market them as Thread-certified.
What is Thread?