Thread borrows the physical and media access control (MAC) layers of the existing IEEE 802.15.4 wireless meshnetwork standard, which forms the basis of the existing ZigBee home automation technology.
As a result, chips are readily available for use in Thread products. In addition, a software upgrade can add Thread to currently existing 802.15.4 products.
Thread merges 802.15.4 technology with other existing technologies, such as 6LoWPAN, which enables the 802.15.4 radio to carry the latest form of the Internet protocol, called IPv6. That technology will simplify routing commands sent over Wi-Fi to a Thread network, the Thread Group said.
Thread also optimizes battery life because it has been designed for use with devices that are asleep most of the time, the group said. Battery-operated Thread devices will last “multiple years,” said Thread Group president Chris Boross. He said it was “hard to compare” Thread’s battery life to the battery life of ZigBee and Z-Wave-equipped devices.
Thread supports more than 250 devices on a network, and its physical-layer throughput of 250kpbs matches ZigBee’s throughput in the 2.4GHz band.
Other key attributes include:
• mandatory encryption;
• elimination of dedicated hubs by distributing the network’s brains across all networked devices to improve reliability;
• mesh network to improve reliability and range; and
• self-healing capability so that if one device fails, the whole network doesn’t fail. In other mesh-network systems, one device acts as a network coordinator and brings down the whole network if it fails.