Thread (network protocol)
Thread is an IPv6-based, low-power mesh networking technology for Internet of things (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.

In July 2014, the "Thread Group" alliance was formed as a working group to aid Thread becoming an industry standard by providing Thread certification for products. Initial members were ARM Holdings, Big Ass Solutions, NXP Semiconductors/Freescale, Google-subsidiary Nest Labs, OSRAM, Samsung, Silicon Labs, Somfy, Tyco International, Qualcomm, and the Yale lock company. In August 2018 Apple Inc. joined the group and released its first Thread product, the HomePod Mini, in late 2020.

Thread uses 6LoWPAN, which, in turn, uses the IEEE 802.15.4 wireless protocol with mesh communication, as does Zigbee and other systems.  However, Thread is IP-addressable, with cloud access and AES encryption. A BSD-licensed open-source implementation of Thread, called "OpenThread", has been released by Google.

In 2019, the Connected Home over IP project (later renamed "Matter"), led by Zigbee, Google, Amazon and Apple, announced a broad collaboration to create a royalty-free standard and open-source code base to promote interoperability in home connectivity, leveraging Thread, as well as Wi-Fi and Bluetooth Low Energy.

Selling points and key features 
Thread uses 6LoWPAN, which is based on the use of a connecting router, called an edge router. Thread calls their edge routers Border Routers. Unlike other proprietary networks, 6LoWPAN, like any network with edge routers, does not maintain any application layer state, because such networks forward datagrams at the network layer. This means that 6LoWPAN remains unaware of application protocols and changes. This lowers the processing power burden on edge routers. It also means that Thread does not need to maintain an application layer. Thread states that multiple application layers can be supported, as long as they are low-bandwidth and are able to operate over IPv6.

Thread touts that there is no single point of failure in its system. However, if the network is only set up with one edge router, then this can serve as a single point of failure. The edge router or another router can assume the role of Leader for certain functions. If the Leader fails, another router or edge router will take its place. This is the main way that Thread guarantees no single point of failure.

Thread promises a high level of security. Only devices that are specifically authenticated can join the network. All communications through the network are secured with a network key.

Competing IoT protocols 
Competing Internet of things (IoT) protocols include Bluetooth Low Energy (including Bluetooth Mesh), Zigbee, Z-Wave, Wi-Fi HaLow, Bluetooth 5, Wirepas, MiraOS and VEmesh.

See also
 Home automation
 Wi-Fi Direct
 Wi-Fi EasyMesh
 DASH7
 KNX (standard)
 LonWorks (standard)
 BACnet (standard)

References

External links
  – official site
 OpenThread
 

Home automation
Building automation
Personal area networks
Mesh networking
IEEE 802
IPv6
Computer-related introductions in 2014