The IoT is a global network consisting of networked things and provides the concept of seamless communication at any time, in any location and with any device. These “things” can be physical or virtual objects that can be detected and integrated into the communication network. However, making these things or devices interoperable, secure, reliable and energy-efficient in smart-home networks and home automation has been a challenge, resulting in an evolving development of wireless technologies.
A smart home is a crucial component in the IoT domain, enabling consumers and stakeholders to directly communicate with various gadgets through the IoT. For consumers, this can translate into energy savings, improved security and safety, and cost savings.
Figure 1: Smart homes encompass a myriad of connected devices and wireless technologies that need to deliver seamless connectivity and interoperability. (Source: Adobe Stock)
A comparison of smart-home protocols
Smart homes leverage a wide range of technologies, including sensors, microcontrollers (MCUs), system-on-chips (SoCs), transmitters and receivers. These devices are equipped with a range of hardware and software wireless network protocol options, including Wi-Fi, Bluetooth, Thread, ZigBee, Matter and LoRa.
Smart-home devices often establish an internet connection via the IP stack, requiring hardware resources like processing power and memory. In addition, many devices can establish local connections using non-IP networks like Bluetooth. This method establishes an internet connection through a smart gateway and delivers reduced power consumption.
The following is an analysis of the most popular wireless protocols utilized by smart-home developers, each with its own uses, benefits and drawbacks.
Wi-Fi
Wi-Fi (802.11) is the most universally recognized protocol standard. Wi-Fi–enabled devices may be quickly set up and activated thanks to the widespread presence of routers or access points in households.
Traditionally, these devices were designed to operate inside the 2.4-GHz wireless range. Typically, in the majority of nations, off-the-shelf devices have access to only a limited number of channels—usually about 12—for broadcasting and receiving. Consequently, the probability of someone on the network experiencing a delay in communication increases as the number of devices connected to Wi-Fi increases.
One of the most recent Wi-Fi technologies is Wi-Fi HaLow (802.11ah), introduced by the Wi-Fi Alliance in 2017. This protocol operates in the sub-gigahertz frequency range, providing a broader coverage area and consuming less power than conventional Wi-Fi devices used in smart homes. It was established to meet the long-range and low-power requirements for many IoT applications.
The pros of Wi-Fi include high data-transfer rates, wide adoption and compatibility, established security standards, high bandwidth and suitability for data-intensive applications, such as streaming video. The cons are high power consumption (not optimized for low-power devices), limited range and costly infrastructure. It may also lead to network congestion in densely populated areas.
Bluetooth
Bluetooth is a prevalent wireless communication technology utilized for establishing connections between devices over short distances. Bluetooth Low Energy (LE) is frequently integrated into a wide range of smart-home products due to its low power consumption.
The pros include low power consumption (Bluetooth LE), ubiquity (nearly all modern devices come equipped with Bluetooth capabilities), ease of setup and configuration, low cost of implementation and wide compatibility with smartphones and peripherals. Among the cons are a limited range compared with other protocols, being interference-prone in crowded environments or frequency bands, and moderate data-transfer rates.
Zigbee
Zigbee, a wireless communication system standardized by the Connectivity Standards Alliance (formerly the Zigbee Alliance), is specifically designed for home automation, in which its low-power and short-range capabilities can be leveraged. Zigbee devices operate within the 2.4-GHz frequency spectrum and create a mesh network, which guarantees efficient use of energy and enables fast communication with minimal delay.
Zigbee’s pros include IPv6 support for direct internet connectivity, low latency and low power consumption. It is also an open standard and offers the possibility of creating scalable mesh networking. The cons include limited range, interference from other 2.4-GHz devices and the need for a Zigbee coordinator (router) for the network setup.
Thread
Thread is a wireless mesh networking protocol based on IPv6 and is designed to be low-power. Thread operates within the 2.4-GHz frequency range and prioritizes scalability and optimal power consumption. It enables mesh networking to improve reliability.
Thread’s major pros include the support for mesh networking (Bluetooth Mesh), delivering reliability and scalability, secure communication, IPv6 support and low power consumption. The main cons are the limited device ecosystem, interference challenges, the need for additional hardware for non-IP devices and limited range.
Matter
Version 1.0 of this open-source connectivity standard was released by the Connectivity Standards Alliance in 2022. To foster interoperability and security, Matter seeks to establish a single standard for smart-home devices.
Key advantages include standardized profiles for various applications, interoperability between devices from different brands, easy integration due to IP technology and secure communication with encryption and authentication.
However, Matter is still in the early stages of adoption and widespread use may take time as the ecosystem develops. Other disadvantages are the need for firmware updates of legacy devices and compatibility with existing devices.
LoRaWAN
LoRaWAN is a low-power wide-area networking (LPWAN) protocol operating on a LoRa network. LoRa is a wireless radio-frequency technology that functions inside an RF band that does not require a license. LoRa is a physical layer technology that employs spread-spectrum modulation and enables long-distance communication but with limited bandwidth. The data transmission employs a narrowband waveform centered around a specific frequency, making it very resistant to interference.
The key benefits include long-range communication (up to several kilometers), low power consumption and infrastructure cost, industry support from major tech companies and a scalable network with thousands of nodes. The drawbacks are low data-transfer rates, the need for gateways for internet connectivity, susceptibility to interference and obstacles, and the prohibitive cost for small-scale implementations.
Z-Wave
Z-Wave is a proprietary wireless protocol that operates within the 900-MHz frequency range and requires a central hub for device coordination. It has a mesh network structure, where each device can function as a possible repeater for other devices.
The advantages are interoperability (devices from different manufacturers work seamlessly), a high coverage range suitable for larger homes and support for mesh networking, enhancing reliability and coverage. The cons are the relatively high cost of Z-Wave devices, the limited bandwidth and a lower data rate than other protocols.
Wireless ICs for smart homes
Wireless technologies enable smart devices, such as cameras, locks, thermostats and lighting, to communicate within a home network. In addition to selecting the right wireless protocol, depending on factors like range, power and cost, it requires a careful choice of wireless SoCs or modules to optimize the IoT design.
For example, smart-home cameras are standalone devices equipped with internet connectivity. These cameras can simultaneously transmit and capture footage over an IP network. Smart devices like smartphones, tablets, PCs and laptops can remotely access these cameras.
At CES 2024, Abode Systems, a do-it-yourself intelligent home security systems developer, introduced the Abode Edge Camera (Figure 2). This wireless home security camera is equipped with AI-at-the-edge capabilities, offers a transmission range exceeding 1.5 miles and boasts exceptional battery life performance. The camera was created through a collaboration between Morse Micro, a manufacturer of Wi-Fi HaLow silicon devices, and Xailient, a firm that specializes in edge AI for computer vision.
The transmission range of more than 1.5 miles is achieved by incorporating Morse Micro’s Wi-Fi CERTIFIED HaLow SoC solution. This device operates on narrow frequency bands, allowing it to overcome transmission obstacles and deliver exceptional performance, even in noisy environments with numerous devices and cameras. In addition, the new camera is equipped with AI models and algorithms developed by Xailient, which allow it to perform sophisticated tasks like object detection, facial recognition and anomaly detection.
Figure 2: The Abode Edge Camera (Source: Abode Systems)
Designed for affordable IoT-connected applications, the SimpleLink series of Wi-Fi 6 ICs from Texas Instruments Inc. (TI) helps designers create secure and efficient Wi-Fi connections at a reasonable cost. These ICs are suitable for applications that function in crowded or hot settings, with temperatures reaching up to 105°C.
The initial offerings in TI’s latest CC33xx series consist of ICs that support either Wi-Fi 6 only or both Wi-Fi 6 and Bluetooth LE 5.3 connections (Bluetooth LE 5.4 for the CC33x1). When connected to an MCU or processor, the CC33xx devices facilitate a secure IoT connection with reliable RF performance for applications like smart appliances, security cameras, smart meters and electric-vehicle charging (Figure 3).
The Wi-Fi 6 companion devices use orthogonal frequency-division multiple access (OFDMA) technology and basic service set (BSS) coloring to ensure rapid and consistent network performance. This enables the connection of several devices simultaneously, without being affected by congestion. The devices also offer support for Wi-Fi Protected Access (WPA) security features, encompassing the most up-to-date WPA3 cryptographic algorithms for both personal and enterprise networks. They also include a secure boot feature that incorporates firmware authentication.
Figure 3: TI’s SimpleLink wireless connectivity devices enable efficient Wi-Fi 6 and Bluetooth LE 5.3 connections in any environment. (Source: Texas Instruments Inc.)
Wireless chips with multiprotocol support are also being developed to deliver design flexibility in IoT devices. A recent example is Atmosic Technologies’ ATM34/e series that supports IEEE 802.15.4–based protocols, including Thread and Matter, as well as enhanced Bluetooth LE for the latest 5.4 standard revision.
The wireless SoC series also offers energy-harvesting capabilities, enabling the devices to capture, use and store energy from RF, heat, light and motion sources. It offers a wide energy-harvesting input range and supports a range of storage devices. Other features include a new scalable memory architecture, which allows designers to select a memory footprint that meets their protocol, application and cost requirements, as well as AES-256 encryption and support for Arm’s TrustZone technology for security.
Nordic Semiconductor’s new nRF54 Series of Bluetooth LE SoCs for the next generation of wireless IoT products supports all Bluetooth 5.4 features, Bluetooth Mesh and future Bluetooth spec updates, as well as Thread and Matter. The ultra-low–power Bluetooth 5.4 SoC includes a new multiprotocol radio and advanced security features in a compact package. It incorporates advanced hardware and software security designed for PSA Certified Level 3, with security features like secure boot, secure firmware update, secure storage and protection against physical attacks thanks to integrated tamper sensors and cryptographic accelerators hardened against side-channel attacks.
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