Thread network simplifies development of IoT devices for smart homes

Article By : Asem Elshimi

Thread network simplifies development of IoT devices for smart homes

Thread has the potential to bring Internet Protocol (IP) seamlessly to low-power, constrained, and mesh devices in smart-home and smart-building settings. The ability to power the Internet of Things (IoT) devices with IP means that developers can run mature Internet applications on constrained mesh devices. It also becomes extremely useful in the context of security.

Thread, being an IP-based standard, has the potential to power smart home surveillance cameras and door locks with the same security solutions that engineers use and trust for credit card transactions such as DTLS and UD. Thread implementation—OpenThread—is an open-source platform, which means that when design engineers use Thread, they get the power of a community of developers working together to perfect the software stack.

Considering how massive the IoT network is, we need security solutions that we already trust. Since Thread is IP-based, for connecting directly to the Internet, there is no need for translators or mapping gateways between a Thread network and the Internet. That simplifies the Thread network structure and makes the developer experience a lot more manageable.

Seamless Internet connectivity also adds another valuable security feature to Thread networks: end-to-end encryption. The data gets encrypted at a smart lock and then traverses through the Thread network and beyond toward the backbone of the Internet until it reaches the cloud server while being encrypted all the way. Design engineers can start imagining the privacy and security advantages this offers to IoT consumers, as the data gets packed at home and only gets unpacked at the cloud data center.

Thread orients itself with networking specifics and abstracts all application layer transactions as IP traffic. So, Thread developers get to build or use any application they prefer, maintaining quite a bit of freedom without having to worry about the networking specifics. The application layer to IoT network is what language is to humans, and networking is equivalent to the brain. OpenThread sets a reliable platform (brain) for different or even concurrent applications (languages).

Consider Thread a really smart multilingual friend. By using Thread, developers can modify their application at any point or even run multiple applications on top of Thread, making it a seamless fit for IoT App layer convergence. The smart home and smart building segments are also adopting Thread because of such incentives and compatibility with communication standards such as IP-based DSL and Wi-Fi.

OpenThread radio implementation

Thread is based on IEEE 802.15.4 low-power, self-healing mesh protocol. From a hardware perspective, silicon providers can offer reliable, low-cost, low-volume, and power-efficient SoCs for Thread end nodes. Semiconductor suppliers are maintaining their SoC drivers within OpenThread, which is an open-source implementation of Thread from a software standpoint. Thread’s growth and development, combined with the power of community, can reduce royalties, licensing costs, and overall design effort.

diagram of Thread implementation technologiesFigure 1 Thread utilizes mature ubiquitous technologies in its implementation to bring IP to low-power mesh networks. Source: Silicon Labs

An error while switching lights on or off is intolerable, considering that everyone takes lights for granted. Thread can solve this by introducing a no-single-point-of-failure scheme to IEEE 802.15.4 self-healing mesh. Thread networks can always reach the server and take reliability to the next level. This means consumers don’t have to worry that their lights won’t reliably switch on/off using a Thread network.

Thread Group has also upgraded Thread into Thread 1.2, integrating several extensions and features while carrying out a significant improvement in Thread 1.2’s compatibility with a smart building. When the Thread network installation is easier, multicasting can be enabled, increasing the possible node count in Thread 1.2.

Thread is also extending its reach by integrating other technologies. For instance, Thread 1.2 can enable commissioning and provisioning using Bluetooth devices. Users can utilize Bluetooth on their phones to commission new Thread devices entering the network for the first time. That makes Thread a glue that connects Bluetooth devices to the Internet. A future smart building might include Thread as its base IP layer for low-power devices while taking advantage of Bluetooth ubiquity and capabilities such as real-time location services.

Protocols working together

The smart home and smart building segments are well equipped with networking protocols such as Wi-Fi, Bluetooth, and Zigbee. Each of these protocols offers an advantage, making it suitable for a specific solution or device. Wi-Fi, the universal wireless connectivity protocol in home and commercial environments, offers reliable and fast RF communications. On the other hand, Bluetooth and Zigbee only offer reliable RF communication for limited-resources, battery-powered devices such as smart thermostats and smart lights.

conceptual illustration of the Thread networkFigure 2 Thread can be conceptualized as Wi-Fi for low power-constrained mesh networking devices. Source: Silicon Labs

On one end of the smart home protocols spectrum, there is Wi-Fi with its ubiquity, reliability, and security. Wi-Fi immediately connects its nodes to the Internet because it’s IP based. So, any Wi-Fi transaction can be fully encrypted end-to-end. However, Wi-Fi is resource- and power-hungry, limiting its utility for constrained mesh devices around the home. Thread can be thought of as an alternative of Wi-Fi with a focus on low power for constrained mesh devices. It extends a lot of Wi-Fi features—security, reliability, and seamless Internet—to low-power nodes that can operate on IEEE802.15.4 radio.

There is a range of low-power wireless mesh protocols such as Bluetooth Mesh, Zigbee, and Z-Wave on the other end of the spectrum. This crew can make incredible power savings for your network. However, none of them are IP-based. Their nodes require special gateways to connect to the Internet. Gateways make it a bit cumbersome to implement device-to-cloud encryption. Translators take away end-to-end encryption capability, which increases security risks and makes life a little complicated, especially for already overwhelmed IoT consumer. Thread fills in that gap.

Thread completes the low-power mesh networking protocols family with the flexibility of IP designs. Can you think of how you use Wi-Fi to operate a printer, send an email, and do many other things? Thread, on the other hand, allows multiple applications to run and thus helps digital assistant switch the lights and control door locks.

table of battery-powered wireless protocolsTable 1 Thread compliments the battery-powered wireless protocols with IP capability. Source: Silicon Labs

OpenThread and IoT convergence

From a consumer perspective, buying a new IoT gadget only to find out that it doesn’t work with the existing system can be painful and discouraging. To avoid that—and in turn, significantly improve the IoT consumer experience—the industry has been seeking a unified IoT platform. Additionally, there is a common consensus across IoT developers and vendors that IoT platforms’ unification will simplify the development cycle and enable more interoperability and compatibility. It’s also important to avoid confusing the unification of platforms with a single-protocol-fits-all solution.

The unification of a platform is about harmonizing different protocols and leveraging their true potential in solving different problems in the IoT space. On the other hand, it is impossible to build one protocol that will fit every use-case in the IoT space. The diversity of protocols stems from the variety of problems that engineers are solving.

So, Amazon, Apple, Google, and the Zigbee Alliance have joined hands to promote the formation of the Working Group driving the Connected Home over IP project. Zigbee Alliance members IKEA, Legrand, NXP Semiconductors, Resideo, Samsung SmartThings, Schneider Electric, Signify (formerly Philips Lighting), Silicon Labs, Somfy, and Wulian are also on board to join the Working Group and contribute to the project.

The goal of the Connected Home over IP project is to simplify the development for manufacturers and increase compatibility for consumers. The project is built around a shared belief that smart home devices should be secure, reliable, and seamless to use. By building on IP, the project aims to enable communication across smart home devices, mobile apps, and cloud services, and to define a specific set of IP-based networking technologies for device certification.

Figure 3 Connected Home over IP project enables IoT convergence by building a unifying IP-based platform. Source: Zigbee Alliance

The Project will define a specific set of IP-based networking technologies for device certification. The goal of the first specification release will be Wi-Fi, Thread and IP implementations for Bluetooth Low Energy (BLE).

For the enthusiastic developers who want to jump-start their development cycle with the Connected Home over IP project, a demo called How to Build a Doorlock using Project CHIP serves as an informative resource.

Thread in IP-BLiS

BACnet International, KNX Association, OCF, Thread Group, and the Zigbee Alliance are working together to better align commercial buildings with users’ connectivity needs and improve smart building products’ integration. The organizations behind the leading technology standards in building automation are now collaborating on the IP Building and Lighting Standards (IP-BLiS) initiative.

Together, they promote a secure multi-standard IP-based infrastructure as a backbone in building automation to replace the inefficient, still-widespread use of siloed solutions. For this purpose, the operation of leading technology standards is to be harmonized, the fragmentation in smart building connectivity reduced, and a broad acceptance of coexistent solutions promoted.

illustration of Thread uses in building automation applicationsFigure 4 Thread has an opportunity to prove its relevance in building automation applications. Source: Silicon Labs

Next, Thread 1.2 offers a few extensions and improvements that make it a seamless fit for building automation applications. Thread 1.2, with its Commercial Extensions, makes some important improvements to the commissioning process, the number of devices able to connect on a network, and the way these networks are configured and managed.

OpenThread adoption

While there are plenty of use-cases and success stories using Thread, it’s still early in its market adoption process. However, Thread is a future-proof technology, so developers adopting it right now should feel safe.

As IoT developers, we ought to keep in mind that we should meet consumer values first while developing cool and awesome technology. Thread brings IP to IoT networks, which simplifies development and improves user experience. Thread also enables unprecedented security and convergence in low-power device networks. Thread’s open-source implementation OpenThread utilizes community support to guarantee a hassle-free developer experience.

IP has been gluing the Internet together for decades, and it is about time to enable IoT networks with IP to unlock new horizons of scalability and security. With its base in IP, OpenThread can run mature and tested applications.

This article was originally published on EDN.

Asem Elshimi is an RFIC design engineer for IoT wireless solutions at Silicon Labs.

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