Designing your IoT device for better network behavior: three expert tips


The electronics industry is buzzing with the Internet of Things (IoT). One engineer described IoT as a vast conspiracy to put network connections on every object in the world—completely independent of whether it makes sense or not.

When we start connecting up all of these “things,” new system requirements creep in that may not be obvious. Your “thing” is no longer happily independent: it is part of a larger system. With connectivity comes new responsibility—in product design and on into the product’s useful life as a network citizen.

Bob Witte,Vice President,
Technology Strategy, Keysight Technologies

From a developer’s point of view, many IoT devices are “embedded designs.” This means they use microprocessors and software to implement functionality, often with an eye towards small compute footprint, just-enough processing power, lean software design and demanding cost targets. This is familiar territory for many design engineers, perhaps with the added requirement of providing a robust network connection. This is often going to be a wireless connection, be it Wi-Fi or some other common standard.

It’s unlikely that you are designing, defining or controlling that entire system. That raises a few key questions, starting with the issue of interoperability: How do you know that your device is going to be compatible with others on the network? Your device may also present a security risk to the network: How much protection can you build in? The assumedly wireless connection is both a source and receiver of RF emissions: How do you make sure it behaves properly in both roles?

Building on these topics, here are a few things to consider as you try to avoid the ills of this brave new world of everything connected.

Ensuring interoperability

Start by understanding the requirements of the larger system as they apply to your product. What other devices, compute resources, servers, etc., must you interoperate with? Because these systems are inherently complex and multivendor, all IoT devices need to “play well with others,” as described in Systems Computing Challenges in the Internet of Things. Creating a robust test strategy will help ensure that you have this covered. My prescription: Think like a systems engineer.

Managing potential security risks

Recent hacks have provided a much-needed wake-up call concerning IoT security. Low-cost devices may not have much data to protect, but they can be a giant security hole that tempts the bad guys with access to the rest of the network. Distributed denial-of-service (DDOS) attacks have been launched using simple devices such as netcams, and even lightbulbs have been hacked. (For some interesting thoughts on this topic, see IoT Problems Are about Psychology, Not Technology.)

Manufacturers that leave gaping security holes may face legal consequences: in early January, the Federal Trade Commission filed a complaint against D-Link for inadequate security measures in certain of its wireless routers and internet cameras.

You can start by plugging known holes in operating systems and other platforms. And, of course, don’t hardcode default passwords. Think through better ways to test for security problems: no, it isn’t easy—but it’s starting to feel mandatory. My prescription: Think like an IT engineer… or a hacker.

Preparing for interference

Your device probably uses one of many wireless connections. First, cover the basics of electromagnetic compatibility (EMC). Be sure the device passes relevant radiated-emission standards so it isn’t spewing RF that interferes with other devices. Also, ensure that your device isn’t susceptible to emissions from other sources.

It’s also important to consider the RF environment your device will live in—especially if unlicensed spectrum is being used, as in the case of Wi-Fi. The great thing about the unlicensed airwaves is that they’re free to everyone to use. The really bad thing about unlicensed spectrum is that everyone is using it and it’s a free-for-all. Thus, you’ll likely have to contend with other emitters in the same frequency span. See Chris Kelly’s post Preparing Your IoT Designs for the Interference of Things for some additional thoughts. My prescription:Think like an EMC engineer.

Wrapping up

My key point: IoT devices may seem familiar and comfortable to engineers who work with embedded systems—but this is a trap. Avoiding this trap starts with a shift in perspective, viewing IoT devices as citizens on a network that has critical requirements for systems, security and RF behavior. Without this shift, we will expose our products—and ultimately our companies—to customer dissatisfaction, customer returns and product liability.