Thread

Some time ago we asked our backers what you would like to know more and quite a few have shown interest in Thread. This blog is thus dedicated to Thread.

So we start with the question, what is Thread?

Well it is something in the same category as Wi-Fi, Bluetooth, 3G, 4G etc that are now house hold names and many people understand what they mean.  Essentially, it is a wireless communication method, but it has been specially designed from the ground up to make secure and seamless communication between low power devices.

Many will ask why can’t we use Wi-Fi or Bluetooth. This is a very valid question especially because you can use Bluetooth between say your wireless headphone and your smart phone, or you can use Wi-Fi between you Laptop and your Printer although via a Wi-Fi router.

 The problem is that Wi-Fi technology has been designed for a very different application. It’s main focus from day one was to exchange lots of data between devices that are commonly powered by mains. Thus, attempts to use Wi-Fi in battery powered applications have not worked very well and you end up either with a device that runs out of battery life every few weeks or you have to duty-cycle it’s power so much it becomes unusable as a responsive device.

Bluetooth, unlike, Wi-Fi had its beginnings in low powered devices like wireless mice and keyboards and then the latest Bluetooth Low Energy, aka, BLE has gone one step further to even lower powered devices like wearables example smart watches and health sensors etc. But Bluetooth has an inherent problem that some people may not be aware of. The problem is it’s low range and unavailability of meshing technology. To explain this further Bluetooth low power slave devices like save power by turning off the radio circuit when they do not expect to talk to the master device like a PC. This means that this is more of a one sided communication and thus results in what we call a star network. A network in which slave devices talk to one master device only. This has a limitation on number of devices that can actively connect to a master.

The problem with Bluetooth was first (commercially) tackled by the likes of ZigBee and Z-Wave. Both technologies introduced meshing, but specifically ZigBee can theoretically have hundreds of devices in a network that talk to each other and pass each others messages around the network thus forming what we call a mesh network.

ZigBee and Z-wave technology can be seen in several home automation products that are on sale now a days. Products with these technologies generally can be found in smart lighting, smart locks, some security systems and also in some remote control applications. The biggest market however for ZigBee has been smart energy and ZigBee has been used in millions of smart meters around the world.

Bluetooth SIG (Special Interest Group) has introduced Bluetooth Mesh technology, which is another competitor in this sector. Bluetooth mesh works differently from Thread and ZigBee in some respects. For example, for those familiar with routing protocols, BT Mesh uses network flooding to transmit packets. This means that a message sent goes to all devices. This is very useful in small home networks and is a special favourite of smart light industry, however this means that the packet latency becomes a problem with number of devices on a network and you cannot transfer large amount of data over this network without completely starving it of bandwidth.

So what is special about Thread, and why do we need Thread when we have ZigBee. The answer lies in the fact that ZigBee has been in development since early 2000s and it has failed to capture the home automation market. It has only risen to popularity in the last few years. ZigBee tried hard during it’s existence to become a one-for-all protocol. Unfortunately, year after year it failed to deliver intra-operability between manufacturers. So, for example if you bought a Zigbee switch from one manufacturer and a ZigBee light from another manufacturer, officially they should work seamlessly together but in realty that rarely happened. Reasons was that the functionality of the Gateway device had to be defined from start. A gateway must support a light switch already to be able to work for it. Thus, a universal gateway that supported all possible ZigBee devices didn’t exist.

Thread has gone back to basics and defined a protocol from scratch and based it on the internet protocols we use on the daily basis, on our computers, on our phone, on our tablets and even on our smart TVs.

The result is that Thread gateway is a much simpler device. It does not need to know what kind of Thread device is being connected to it beforehand and thus is much more universal. So much so that there is chance that soon Thread gateways may be built in to home Wi-Fi routers as standard.

Thread then continues to make device connectivity simpler and secure. The most common method to bring a Thread device onboard a gateway is by scanning its QR code via a Smartphone app. The Smartphone app acts as a security broker between the Thread gateway and the Thread joining device. All this happen using security technologies that we use on the web and have been tested and developed over many years. In a nut shell, Thread provides world class security of data between devices.

Thread still provides meshing so there can be up to 250 devices on a Thread network. A recent comparison between home automation protocols (ZigBee , Thread and BT Mesh) found Thread to be the best at routing packets and lowest latency of messages. You should not have to wait 5 seconds between pressing the switch and seeing the light turn on.

Thread also gets rid of single point of failure. For example, in ZigBee there is only one Gateway and if it fails then the network connectivity to internet fails. Also, you cannot commission new devices to the network without a working gateway. Thread supports multiple Gateways and in a network with more than one gateway, if one fails, another one automatically takes over it’s responsibilities.

From a developer point of view Thread provides the simplest way to create wireless mesh networked devices. As time goes on we will see more and more thread related devices appear on the market. ZigBee alliance in cooperation with Thread have developed the DotDot application layer that brings many years of ZigBee learning to Thread. Although Thread is application layer agnostic, but I believe overtime we should see more and more Thread devices working together either though Cloud-to-Cloud integration or just talking to each other on a local Thread network.

Thread, believe it or not, is the future of home automation IoT devices. And with all the advantages it presents it may become the defacto for Industrial IoT as well.

**Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of Novo Innovations Limited.