Granite River Labs, GRL
Choosing the perfect IoT protocol is akin to finding the ideal home interior — your answer will vary depending on who you’re asking and what their specific needs are. Whether you’re choosing between Thread, Zigbee, Bluetooth, Wi-Fi, or Matter, understanding the distinct array of features that each IoT architecture brings, such as power consumption, topology, latency, scalability, interoperability, and even cost, will help determine the one that suits your needs best.
If you’re still on the fence about which IoT network to choose, here’s your chance to delve deeper into analysis about the advantages and disadvantages of each network, how they interact with the overlaying Matter application layer protocol, as well as its compatibility with other connected devices.
How IoT protocols impact power consumption and device suitability
As IoT networks gain rapid adoption, battery-powered sensors and devices are also surging in use. Consequently, the need for IoT protocols capable of delivering superior performance while conserving power is on the rise.
The design of IoT protocols directly affects power consumption levels, which in turn significantly impact device performance. Hence, choosing the appropriate IoT protocol for your specific device usage becomes paramount in guaranteeing optimal performance and preserving battery life.
Thread power consumption
Thread is designed to be a low-power protocol suitable for battery-operated IoT devices. It uses mechanisms like low duty cycle, sleeping nodes, and energy-efficient routing to minimize power consumption. Thread devices can achieve long battery life by optimizing sleep periods and reducing energy usage during idle times.
Zigbee power consumption
Zigbee is also known for its low-power operation, although it tends to draw more power than Thread due to its larger software stack. Primarily used with battery-powered devices, Zigbee can extend device battery life through low duty cycle, sleep modes, and efficient network routing. With the right design and implementation, higher power levels of Zigbee can be circumvented to optimize power consumption.
Wi-Fi power consumption
Wi-Fi is an IoT protocol with relatively higher power consumption compared to low-power alternatives like Thread or Zigbee. This is because Wi-Fi radios and devices require more frequent communication and active connection to transmit data, which drive up power consumption. However, there are power-saving features like Wi-Fi Power Save Mode (PSM) that can help minimize power consumption in Wi-Fi devices.
Bluetooth power consumption
Bluetooth, particularly Bluetooth Low Energy (BLE), is designed to be power-efficient and suitable for low-power IoT applications. BLE devices utilize sleep modes, efficient data transfer, and low-power idle states to conserve energy. Bluetooth’s scalability and low power consumption levels make it a popular option amongst battery-powered IoT devices that rely on short-range connectivity.
How IoT topology impacts data traffic
IoT topology refers to the way different objects and connections interact within an IoT network. Topology influences a myriad of factors such as traffic, scalability, power consumption, and even how quickly malware can take hold of your network. Understanding the various types of IoT topology and how they function is therefore critical for deploying and maintaining networks.
Mesh network topology of Thread and Zigbee
Thread and Zigbee utilize a mesh network topology, where devices are linked directly in non-hierarchical fashion to route data across the network. This allows devices to not only receive data but also serve as intermediaries for transmitting data to other devices.
Consequently, these protocols establish highly reliable networks with extensive coverage, eliminating the necessity for additional repeaters solely dedicated to rebroadcasting wireless signals to devices farther away, as is commonly required in other wireless protocols.
Star topology of Wi-Fi
Wi-Fi utilizes a Star topology, where all devices are connected to the central hub or router that acts like a server and the connecting nodes act like clients. When the central node receives a packet from a connecting node, it can pass the packet on to other nodes in the network. Although relatively immobile and costly to maintain, the centralized design of star topologies make them user-friendly and allow them to continue functioning even when one device or cable fails.
Hybrid topology of Matter
Matter combines the mesh network topology of Thread and star topology of Wi-Fi by operating on top of both of them. Using Thread border routers, Matter networks can allow users to enjoy the benefits of both topology types by creating a hybrid network.
Figure 1: Mater IoT network topology and its Wi-Fi and Thread components
Range and data rate of common IoT protocols
For most smart home use cases, popular IoT protocols such as Zigbee, Thread, Bluetooth, and Wi-Fi offer similar range capabilities that are optimized for short to mid-distances within an average home environment. This means that connected IoT devices can communicate effectively across rooms and even floors with these IoT protocols.
While environmental factors can influence the absolute network range, these differences are typically negligible for the average home automation scenario, which typically involve relatively low amounts of data. When it comes to providing reliable and efficient networks suited for controlling smart devices, monitoring sensors, and managing home automation systems, the main IoT protocols will do just fine.
Figure 2: Data rate and range comparison graph between Wi-Fi, Bluetooth, Zigbee, and Thread
Latency of common IoT protocols
According to a Silicon Labs benchmark that compared the connectivity of mesh networks Bluetooth, Thread, and Zigbee across 24 home devices, Thread performed the best with small and moderate payload with a smaller peak and less spreading(<100ms). For a small payload, all three networks spread up to 90 ms, well under the market target of 200 ms. For moderate payload, Zigbee performed the best with most packets receiving 80 ms latency and spreading up to 130 ms. Bluetooth latency had the greatest variation between 20 to 200 ms.
Figure 3 : Zigbee, Thread, and Bluetooth multicast latency 24 Node Network – Small payload
Figure 4 : Zigbee, Thread, and Bluetooth multicast latency 24 Node Network – Moderate payload
Source: Silicon Labs
Scalability of various IoT protocols
Scalability is perhaps one of the top-most considerations when people first look towards installing an IoT network. Beyond just a matter of range, effective scaling must also be done with security, cellular coverage, and device connectivity in mind. It’s also important to consider the difficulty of not just scaling-up, but having a flexible enough network that can be easily scaled down.
Thread mesh network
Thread’s mesh networking is designed with scalability in mind. By allowing devices to act as relays, network coverage can be easily expanded to handle a large number of devices. Thread networks can accommodate up to hundreds or even thousands of devices, making it suitable for large-scale IoT deployments.
Zigbee uses the IEEE 802.15.4 wireless mesh protocol that is known for its scalability and is therefore widely used in applications involving a large number of devices. Zigbee networks can support hundreds or even thousands of devices, thanks to its mesh networking capabilities and efficient protocols.
Wi-Fi networks are traditionally deployed in homes as they have a relatively high scalability due to the widespread availability of Wi-Fi infrastructure. Although Wi-Fi networks can handle a large number of devices, their networks must be scaled up by deploying more access points or utilizing mesh networking options provided by certain Wi-Fi standards. On average, Wi-Fi networks consume more power compared to Zigbee and Thread.
Bluetooth, particularly Bluetooth Low Energy (BLE), is not inherently designed for large-scale deployments with a massive number of devices. While Bluetooth can support multiple devices, its primary focus is on connecting a limited number of devices in close proximity, such as personal devices, sensors, or accessories.
Interoperability in the IoT context refers to the ability for systems to transport meaningful and actionable information between systems. To be truly interoperable, IoT networks must have physical communications infrastructure to transport data (technical interoperability), a shared syntax to share specific types of data (syntactic interoperability), and semantic IoT deployments to interpret transferred data.
Thread is designed to enable interoperability among devices within a Thread network by providing a common protocol for all Thread-certified devices to connect and communicate. However, interoperability with devices outside the Thread ecosystem may require additional bridges or gateways.
Similarly to Thread, Zigbee networks allow Zigbee-certified devices to work together within the network. Certifications are given out based on adherence to Zigbee specifications. Ultimately, the viability of Thread and Zigbee networks depends on the market penetration of their respective ecosystems, and the types of supported-devices that end-consumers demand.
Wi-Fi possibly has the most widespread interoperability support across devices and manufacturers. Wi-Fi-enabled devices from different manufacturers can connect to a Wi-Fi network and communicate with each other as long as compatibility with common Wi-Fi standards are fulfilled. This enables interoperability among a wide range of Wi-Fi devices, such as smartphones, laptops, IoT devices, and other network-connected devices.
Bluetooth has excellent interoperability support for short-range device connectivity. Bluetooth devices, including smartphones, tablets, audio devices, and IoT devices, can typically communicate with each other via the network regardless of their manufacturer. Bluetooth's standardized profiles and protocols ensure interoperability for various use cases, such as audio streaming, file transfer, and device control.
Matter is a relatively new IoT protocol that aims to enhance interoperability among smart home devices by marrying the pros of underlying technologies like Thread, Wi-Fi, and Ethernet. Matter-certified devices from different manufacturers can communicate with each other using a common application layer, regardless of the underlying network protocol.
Cost considerations in IoT network deployment
Customizing IoT networks can contribute up to as much as 70-80% of the total cost, which is why it is critical for customers to have a firm understanding of what various IoT networks can do for them based on the information shared above thus far. By selecting the right IoT network base, consumers can save a significant amount of time and resources on customization.
As a low-power, low-data-rate protocol, Thread can be implemented with relatively inexpensive hardware components. This is further helped by the fact that Thread operates on the 2.4 GHz frequency band, which is widely supported by affordable radio modules. However, the cost of Thread-enabled devices themselves can vary depending on the specific hardware requirements and features desired. Additional licensing fees associated with Thread certification should also be considered and are typically managed through the Thread Group membership.
The low-cost implementations of Zigbee have made it a popular IoT network for a wide range of applications. Zigbee-enabled hardware components are widely available and relatively affordable. In addition to the 2.4Ghz frequency band used by Thread, Zigbee also uses sub-GHz frequency bands commonly found in inexpensive wireless modules. The overall cost of a Zigbee deployment can vary based on the number of devices, network infrastructure requirements, and any additional features or certifications desired.
Wi-Fi is a widely adopted protocol with a broad range of hardware options available at various price points. Wi-Fi modules and chips are generally affordable due to the widespread use and competition among manufacturers. However, the cost of a Wi-Fi deployment can be influenced by factors such as the number of access points, network infrastructure requirements, and potential licensing fees associated with certain Wi-Fi features or certifications.
Alongside Wi-Fi, Bluetooth is also a network supported by a wide range of low-cost hardware options, making it a cost-effective choice for many IoT applications. Bluetooth modules and chips are commonly available at affordable prices because of said widespread adoption. Overall cost of a Bluetooth deployment can vary based on the number of devices, integration requirements, and any additional features desired.
IoT network certification and membership fees
On top of deployment costs, it’s also important to consider membership and certification fees when calculating the total cost of IoT deployment. A summary of the fee table can be found below.
*Note that the fees listed above do not include costs associated with testing or 3rd party service (ex. Bluetooth Qualification Expert support fee)
Understanding IoT protocols in an evolving connectivity landscape
In conclusion, understanding the differences between IoT protocols, such as Zigbee, Bluetooth, Thread, Wi-Fi, and Matter, is essential for navigating the evolving landscape of smart devices and interconnected systems. Long established protocols such as Zigbee, Bluetooth, Thread, and Wi-Fi each with its own strengths and areas of expertise. Zigbee excels in low-power, mesh networking applications, while Bluetooth offers seamless connectivity for short-range personal devices. Thread provides robust and secure communication, while Wi-Fi delivers high data transfer rates and broader device compatibility.
The emergence of Matter, built on Thread and other technologies, signifies a promising development in the IoT space. Matter aims to streamline interoperability, simplify device integration, and enhance the smart home ecosystem. By leveraging existing protocols like Thread and Wi-Fi, Matter seeks to bridge the gap between devices from different manufacturers, offering a unified and seamless user experience.
About the author
With more than 7 years of experience in wireless and RF testing, Charles is familiar with various protocols: Bluetooth, Zigbee, Thread, Matter. He is always willing to help customers to clarify doubts and questions about Matter and Thread testing requirements.