Over the last decade or so, interest in IoT technology and connecting devices to one another, and to the internet, has increased. Of course, one of the key elements necessary to connect devices is wireless communication. There are several wireless interfaces, such as cellular, Wi-Fi, Bluetooth, ZigBee, LoRa etc., that are prominently used in different industries to make these connections. However, choosing the right wireless technology is vital for the success of any product. One should consider several factors before zeroing in on the right wireless technology for your goals. Some of the factors to consider include:
- Wireless range/ coverage
- Power consumption
- Ease of provisioning
Selecting the right technology to get the best results and satisfy all your requirements is a challenge, and what’s “right” may vary depending on use case. For instance, cellular technology is often preferred for a mobile device used in logistics applications, as it has excellent coverage. However, cellular technology is power-hungry; it would be difficult for the battery-powered device to operate for long periods of time. Similarly, LoRa, with a wide wireless range and low power consumption, is an excellent choice for applications such as smart metering. But it has a relatively low data throughput, and therefore may not be the ideal choice for certain industrial applications.
What is Thread?
One of the recent entrants to the wireless communication space is Thread. Thread is an IPv6-based, low-power, open source, mesh networking protocol for connected devices, backed by Nest Labs (a subsidiary of Google) and other industry bigwigs. Like ZigBee, it uses IEEE 802.15.4 wireless mesh protocol, but, being internet protocol (IP)-based means a Thread network can seamlessly connect to the internet without needing a translator or a gateway in between. Thread operates on the 2.4GHz ISM radio band, the same as ZigBee, and offers a throughput of 250 kbits/s with a typical range of about 30 meters. It employs spread-spectrum techniques to provide immunity to interference. Thread’s low power consumption means that a coin cell could power it for almost two years.
Thread as a Mesh Network
As a mesh network, Thread can have several hundred devices communicating with each other and the cloud. A typical Thread network would consist of an endpoint device, router node and a border router. A typical endpoint would be a battery-powered device that communicates with a parent router. A router node would receive packets from devices on the network and forward them to the rest of the network. The border router is a device that facilitates communication between a Thread network and a non-Thread network, such as Wi-Fi or Ethernet, by forwarding packets.
Benefits of Thread
Because Thread is a self-healing mesh network, it offers many benefits. One is avoidance of a single point of failure. That is, if any router in the network fails, another router automatically takes its place. Unlike ZigBee, for example, Thread devices can be linked to multiple border routers, making the network more reliable. Another advantage is that, being mesh, the Thread network is highly scalable. Each Thread network can scale to hundreds of devices. Thread also benefits from being built on IPv6 to take advantage of end-to-end routing and addressability. Any two IPv6 endpoints, whether on the same Thread mesh or across networks, can communicate, end-to-end, with easy and well-understood internet routing mechanisms moving packets from one endpoint to the other.
One of the biggest benefits of Thread is that it can provide a high level of security. Security breaches associated with IoT and connected devices are on the rise, and are a major barrier to legacy device connectivity. All devices in a Thread network are automatically authenticated and communication is encrypted. Thread networks use a secure, financial-class encryption and the technology has plugged the obvious security loopholes found in other wireless protocols.
An IoT device should be easy to deploy in the field, which is another factor in selecting the right wireless technology. Thread devices can be easily set up using a smartphone or a tablet. Users can securely connect devices to each other, and to the cloud, for easy control and access from anywhere.
Thread is built on 6LoWPAN, which is the same radio protocols as that of ZigBee; an IEEE 802.15.4-based specification for high-level communication used to create personal area networks with digital radios. It’s possible that, with just a software upgrade, an existing ZigBee module can be converted to a Thread module. For legacy ZigBee users, it would be relatively easy to migrate to Thread technology. Availability of OpenThread, an open-source implementation of Thread, is likely to accelerate the development of products that leverage Thread. However, the limited availability of off-the-shelf border routers, and the use of less preferred mesh topology, is a challenge for its adoption into IoT devices.
The Future of Service Mesh
Thread has great potential, and can be considered a very good alternative to existing wireless communications options with the added benefit of Wi-Fi-like features. Because it’s open source and backed by large semiconductor manufacturers and technology heavyweights, Thread technology is poised to gain substantial momentum over the next few years. It may eventually emerge as the primary choice for medium throughput, low power IoT applications.