Design engineers are challenged to balance hardware requirements with software innovation as they satisfy consumer expectations for an easy-to-use smart product that adds convenience and efficiency to homes. Even basic products such as smart light bulbs are equipped with electronics incorporating a multitude of technologies and capabilities.

A well-designed smart home product addresses numerous elements – including connectivity, interoperability, security and upgradability – in a way that satisfies consumer desires while accounting for the evolving smart home market. As a result, developers make tradeoffs between product features, application requirements and system complexity.

This article explores some of these Internet of Things (IoT) device features, application requirements and system complexities.

Ensure Interoperability

Few smart home products operate in isolation. Instead, they interconnect and communicate to enable a complex smart home system. Today, different smart home ecosystems are characterized by different software requirements. Some use Thread for communications, others use Bluetooth Low Energy, and others use Zigbee. Within this complex landscape, developers must ensure connectivity and interoperability at the application level.

In fact, interoperability is critical to success in the smart home market. Most consumers lack the technical know-how and patience to troubleshoot smart home device and network issues. Should an interoperability issue cause the home network to be unstable, the latest smart device added to the network usually takes the blame.

Recognizing this problem, major ecosystem vendors including Apple, Amazon and Google are collaborating on a unifying standard called Matter to ensure interoperability among all smart home devices. Meantime, engineers can use certified silicon products from known and trusted partners to avoid their devices being the reason for a home network interruption.

While traditional technology standards like Bluetooth, Wi-Fi and Zigbee serve as the interconnective tissue between the hardware and software used to build smart home devices, they’re not always as interoperable as consumers require. It’s clear that consumers gravitate to plug-and-play products and applications. The Matter standard will enable this by increasing interoperability across all IoT standards, in turn increasing consumer adoption of IoT devices.

Matter brings the connectivity cohesiveness a smart home requires. By addressing the connectivity and interoperability needs of IoT products, it will free developers to focus on innovation at the application, product and hardware level.

Support Current and Future Protocols

Matter won’t immediately replace all other connectivity protocols. In fact, it builds on existing ones, including Thread, Zigbee, Bluetooth Low Energy and Wi-Fi. It will take time to migrate existing smart homes to the new Matter protocol, so engineers must prepare to support multiple standards in their gateway in the meantime. This migration period has already started, with most IoT hub vendors adding the Matter standard to their devices.

Standards like Bluetooth Low Energy and Wi-Fi are not expected to be made obsolete by Matter. Bluetooth Low Energy will be used in Matter for commissioning. Plus, new Bluetooth-based features are coming, such as next-gen audio for streaming.

Wi-Fi will remain as the main access point in homes to enable a high-bandwidth tunnel for content like video streaming and browsing the web. Wi-Fi also plays a key role in Matter, particularly in the hub where it seamlessly integrates Matter devices using low-power Thread technology (for instance, lights and light switches) and Matter devices using Wi-Fi (for instance, smartphones). In doing so, Wi-Fi allows smartphones to seamlessly control devices in the smart home Matter network over multiple radio technologies.

Since Matter supports both Wi-Fi and Thread as IP-based communication protocols, no bridging functionality is needed at the application layer. In theory, this means all smart home devices can use Wi-Fi. However, in practice, Matter over Wi-Fi will likely be used primarily in the mains-powered infrastructure (for example, hubs, smartphones, TVs, set-top boxes and smart speakers), where it is combined with a Thread radio to offer seamless connectivity across the full Matter network. This concept is called a border router.

Matter over Thread is also expected to serve the majority of sensors and actuators in the home as it is more energy efficient, lower cost and has significantly lower latency compared to Wi-Fi based sensors and actuators.

Matter hubs combining Wi-Fi and Thread that allow all Matter devices to connect and communicate with each other similar to Wi-Fi access points – regardless of the underlying protocol they use – are being rolled out today. Examples include AppleTV, Apple Homepod Mini and the Google Wi-Fi system. Such infrastructure in the home helps device manufacturers avoid another hurdle/complexity by easily reusing existing hubs rather than developing new ones.

Incorporate Artificial Intelligence in IoT Devices

Many wireless devices, including those in IoT, are incorporating or beginning to incorporate Artificial Intelligence (AI) to take advantage of the growing compute power of IoT devices.

Based on the data collected by sensors in IoT devices, engineers can program software to shape device capabilities in interesting ways. Examples of where AI can be used in a smart home include:

• Enabling a more proactive home where smart devices learn behaviors and automatically define custom routines to save energy and increase comfort based on the home owner’s preferences and habits.
• Combining device inputs in a home network to enable a better user experience. For instance, maximizing security by combining input from microphones (i.e., smart speakers), contact sensors, motion detectors and cameras to take immediate action when hearing the sound of glass breaking and detecting motion, which might indicate a break-in.
• Automatically monitoring a person’s breathing by using ultra-wide-band to detect possible health issues and using Matter connectivity to notify a caretaker in case of an emergency.

Supporting the Many Radios and Standards of the IoT

To date, developers have supported multiple protocols by integrating multiple radios via their gateway using more compute-capable and energy- efficient silicon technology. It’s safe to assume Matter infrastructure in homes will support Wi-Fi and Thread radios. Thread radios provide the same ease of use as Wi-Fi.

However, it’s not always easy to integrate radio frequency (RF) into products. The challenge is overcoming radio signal interference introduced by the various connectivity protocols. Moreover, RF signals in homes are subject to reflections, attenuations, interference and distortions, all of which can result in lost connections and limit the range of communications. Vendor reference designs and modules can help here.

Choosing to build a custom radio or use a certified module typically comes down to time-to-market concerns and whether engineers are able to manage the redesign of a radio subsystem to accommodate each new standard. Many find it’s a better option to call upon a communications controller that supports co-existence of multiple protocols while protecting packets and ensuring efficient communications between devices and the smart home network.

In fact, engineers can work with a partner experienced in developing full-system solutions for coexistence of different radio bands. These types of partners fully understand the RF radio and how to accurately use RF filtering technology to maximize throughput and minimize interference between radios. Many of today's RF module solutions combine Zigbee, Thread and Bluetooth Low Energy in one radio to work virtually as three radios with no degradation. For example, if a radio on the chip detects Wi-Fi interference or the device sensor is near a Wi-Fi access point, an optimized RF solution will select the best signal path to ensure interference robustness and reliable range.

Addressing Security Concerns

A looming concern with smart home products is the potential to serve as a vector for a security breach. The reality is that smart home devices can be the equivalent of leaving the front door open. According to one recent study, nearly half of the 42% of Americans that use smart home devices haven’t taken steps to protect them from attack. Another study – by the European watchdog Euro-consumers – found that hackers capitalize on smart home vulnerabilities to launch de-authentication attacks, instructing devices to disconnect from the home Wi-Fi. Analysts discovered that some smart home apps transmit unencrypted data that hackers then use to acquire Wi-Fi passwords and access sensitive information.

Say a remote control has a microphone. If the remote is hacked, the attacker might access sensitive information. A smart bulb hack could be the entry point into a home network to compromise other devices, such as checking Wi-Fi traffic and intercepting personal information. These attacks could keep a home owner from entering their house, could prevent doorbells from responding to motion or force homeowners to replace all their connected devices.

The Matter protocol is forward-thinking around security, as evidenced by much attention to security in the specification. By taking advantage of many yet-to-be-seen features in IoT devices plus general security practices – for example, certificates to verify a genuine device – engineers can address security concerns.

That said, device vendors need to monitor potential security breaches and apply patches to fix security loopholes as they receive them from silicon/software stack vendors. Device design engineers can implement security measures in both software and hardware. Using over-the-air (OTA) means, they can then apply updates throughout the device lifecycle. With that in mind, they must ensure sufficient Flash to accommodate downloads and store them until they've been applied.

Another requirement is to apply a secure boot, which makes it possible to prevent device access by closing off all silicon interfaces so no one can read or write to Flash. The hardware can also verify the integrity of software before running it to help ensure only authenticated software can be executed. Device developers will be glad to hear that silicon manufacturers are making it easier to implement this functionality in products in two ways. They are providing reference applications and guidance, as well as building root of trust and other security elements into their silicon to facilitate development of secure solutions.

Focus on the Consumer Experience

Developers creating IoT-friendly smart home products must constantly be aware of new technology developments, the latest standards initiatives and customer desires. In addition to making design tradeoffs to accommodate performance parameters, they must also consider AI, the optimal business partner for radio devices and more. While a daunting task, engineers can succeed by harnessing expertise in software, hardware and standards – and ensuring these play together harmoniously to enable and expand the IoT.