Thread is an IPv6-based, low-powermesh 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 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 announced, which is a working group with the companies Nest Labs, Samsung, ARM Holdings, Qualcomm, NXP Semiconductors/Freescale, Silicon Labs, Big Ass Solutions, Somfy, OSRAM, Tyco International, and the lock company Yale in an attempt to have Thread become the industry standard by providing Thread certification for products. In August 2018Apple joined the group raising hopes it will help popularize the protocol. Thread uses 6LoWPAN, which in turn uses the IEEE 802.15.4 wireless protocol with mesh communication, as does Zigbee and other systems. Thread however is IP-addressable, with cloud access and AES encryption. A BSD licensedopen-source implementation of Thread has also been released by Nest. In 2019, the Connected Home over IP project, 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
As mentioned above, Thread uses 6LoWPAN, which is based on the use of a connecting router, called an edge router. 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.
