Nest has made available to developers the Weave protocol used to connect various IoT devices.
Weave is a low-power, low-bandwidth, low-latency, secure, device-to-device communication protocol that was developed and used by Nest for their devices. While the protocol is still proprietary, Nest has open it up to developers around the world to start using it and providing feedback.
Weave runs on Thread or WiFi using the 802.15.4 or 802.11 radio waves. Any IoT device running on one of these two radio waves and supports software upgrades can be enhanced to use Weave and benefit from all its capabilities. The minimum hardware requirements are ARM M-class SoC with 64 KB of RAM. Weave is optimized to run on such devices for at least a couple of years on a battery, according to Nest. Weave also runs on ARM R and A-class controllers, the later targeting home appliances that are always connected to the power line. Weave can be enhanced to run over other network protocols such as Bluetooth, LTE or Ethernet.
An IPv6-based protocol, Weave can connect devices using the standard communication path – device-WiFi router-cloud-WiFi router-device-, or between devices via a WiFi router, but it also enables devices to communicate directly to each other, avoiding the latency penalties applied by a trip to the cloud and communication disruptions introduced by Internet outages. Nodes in a Weave network receive each an IP6 address and can communicate with each other even though they belong to different physical networks.
Weave implements security by encrypting all messages no matter what underlying network protocol it happens to run on. It also separates devices into different categories based on their purpose – lightning, door locks, thermostats, etc. – using different keys to encrypt the messages between devices in the same category. This introduces a layer of protection so one could not unlock the door by finding a security gap in the lightning fixtures.
Nest Weave protocol with its low entry barrier is announced in the midst of a controversy raised by Apple’s HomeKit framework. HomeKit is a similar IoT solution but it comes with a different approach. Not just the software development process is centered around Apple’s tools and need to follow strict certification rules, but for security reasons device manufacturers have to use Apple-approved controllers, such as Marvell’s EZ-Connect, an iOS device is mandatory to operate such devices, and even an Apple TV is needed if one wants to use Siri, according to The Register. Manufacturers who thought they had compatible hardware that needed just a firmware update now have to redesign their solutions to be approved by Apple. Nest’s solution is much more permissive than Apple’s, being more attractive to manufacturers, but security remains paramount when it comes to IoT devices. Will Apple’s approach pay off in the end? Will Weave/Thread dominate the IoT landscape? Time will tell.
