The right balance of features, size, power, and cost, while supporting dual-protocol simultaneously on one device – these are the elements that developers think about when considering networking technologies. In this Tech Talks session, our Field Applications Engineer (FAE), Tim Sams, details what developers need to know to get started with 15.4 Mesh Networking (Zigbee and Thread protocols) along with our appropriate tools and platforms. Click here to hear the entire 15.4 Mesh Networking Technologies session and register now for future Tech Talks. Below are some key takeaways from Tim's session.

The Foundation of Zigbee Technology 

Zigbee technology is built in a full stack on four layers as follows: 

• Layer 1 (Radio | IEEE 802.15.4) – built on a globally available radio standard that operates at 2.4 GHz ISM bands, with a low data rate protocol meant for mostly monitoring and control. 
• Layer 2 (Connectivity | Network Protocol Stack) – a Zigbee PRO networking stack created and maintained by the Zigbee Alliance. This networking stack allows for an intelligent mesh network routing, making it extremely scalable, reliable, and robust, especially for lower-powered devices. 
• Layer 3 (Interoperability | Application Layer) – a well-maintained specification library, also known as the Zigbee Cluster Library, this layer is the common language that allows for all the devices on the Zigbee PRO network to speak to and understand each other, e.g., a device’s definition, characteristics, and description. 

Layer 4 (Conformance |Certification & Logo) – the enforced conformance and interoperability components through a couple of certification levels: platform certification and product certification. The former is achieved by Silicon Labs to verify the operation of our hardware and stack software as a certified platform where developers’ devices can be built upon. The latter is achieved by customers and device makers by testing their implementation of a device type using Silicon Labs’ stack and hardware – this includes joining the Zigbee Alliance to use the Zigbee name and logo on their products. 

The Power of Zigbee Software

There are many reasons why developers use Zigbee technology. First, Zigbee software has a complete solution with a fully integrated stack architecture and fully certified Zigbee 3.0 platform, including Zigbee 3.0 devices, Green Power device support, and smart energy application support. Second, it is highly flexible and easy to use with its seamless integration with AppBuilder, handling all the common use cases like commissioning, security features of Zigbee, OTA upgrades, and bootloaders. Third, the Zigbee software is field upgradable wherein developers can do over-the-air firmware updates and NCP firmware updates over a serial interface.  

Tim also gave a quick overview of the Zigbee 3.0 (EmberZBet) SDK roadmap, which includes building a certification program for Zigbee devices that developers want to connect to their hubs. This initiative is called Works With All Hubs. Another similar program is Friends of Hue, which is specifically for Philips Hue devices and ecosystems. Sometime around Q2 of 2021, new networking improvements to the Zigbee PRO network will lead to an upgrade to Zigbee R23, adding new security features, commissioning features, and improvements to routing.

Thread and the OpenThread SDK

Thread is another 15.4 mesh-based technology supported by Silicon Labs. It has similar technology as Zigbee but Thread’s key differentiator is that it is IPv6-based. Thread also does not define an application layer, as it is a networking protocol only, providing the communication layer for any kind of application layer. Tim likened this structure to a Wi-Fi network being a Wi-Fi backbone, but all the TCP, UDP, and application layers that run on a Wi-Fi network are up to the user. Just like Zigbee, Thread is intended for control and automation and was built around the IoT premise, specifically for smart home and commercial building applications.

OpenThread is an open-source implementation of the Thread networking protocol and it is currently at specification version 1.1. We currently offer OpenThread with 1.1. certification on three devices: EFR32MG12, EFR32MG13, and EFR32MG21.

Managed Wi-Fi Co-Existence and a Common Platform

Wi-Fi co-existence is one of the many value add-ons when using 15.4 Mesh protocols through our platform, especially in gateway type devices. These gateway devices typically have an enterprise-grade, multiple-input, multiple-output Wi-Fi, operating in adjacent channels in the 2.4 gigahertz ISM bands – making them prone to mistransmissions and other errors. To solve this problem, we developed a 1-4 wire managed Wi-Fi coexistence interface that manages packet traffic based on the 802.15.2 standard. We also offer a tool called Network Analyzer that provides a holistic view of what is happening across the network, combined with our hardware packet trace interface, without negatively affecting radio performance.

All our protocol stacks – Bluetooth, OpenThread, Zigbee, and Flex SDK – are all built on a common platform. The same Radio Abstraction Interface Layer (RAIL) and bootloaders are used, no matter what hardware or protocol stack is used. This provides extreme maximum flexibility and makes developing with several different protocols significantly simpler, because of so many shared components, tools, and development environments.

Getting Started with Mesh Module Portfolio

To get started with your mesh networking development, visit our Thread Networking Solutions and Zigbee Wireless Networking Systems product pages which include comprehensive information about what kits to order, including wireless starter kits that include three boards for developers to run a small mesh network with their devices.

Q&A

The Tech Talk ended with a question and answer session, and you can find the transcript here.