Gartner Research predicted that 8.4 billion connected things will be in use globally this year, a 31% increase from 2016. And it expects this number will grow to 20.4 billion by 2020. Indeed, the firm expects total spending on endpoints and services to reach almost $2 trillion in 2017 alone. As organizations look to capture this quickly growing market, understanding the nuances of IoT wireless design is critically important.
I’ve helped design hundreds of wireless modules for every application imaginable — from bike computers to golf course watering sensors. And I can say with certainty that low-power IoT wireless design is more times than not the area of greatest challenge for IoT product design. The reason? The very concept of where a connected product begins and ends often gets stretched across hardware, firmware, local mesh and device operations in the cloud. Once you fold in details like unit size, cost and power, it is quickly clear that you must very carefully think through your wireless design.
To that end, there are typically four stages in the engineering timeline for IoT devices: design, implementation, certification and launch. While that in and of itself is not too dissimilar from the process for other products, if you aren’t careful, the IoT process can really bog down in the certification phase. Let me explain. When you design your own radio, the FCC considers you to be an “intentional radiator.” Although it defines it simply as any device that is deliberately designed to produce radio waves, the implications are not simple at all. In fact, as an intentional radiator, the FCC requires that you comply with CFR 15.249 and successfully pass hundreds of tests.
It is my experience, however, that many companies do not get their design right the first time. The result is that they need to make a change or two. Perhaps they need to alter their antennae, ground plane, RF firmware or board layout. Regardless of the change, any modification requires a new round of testing. This testing ensures that the change did not alter CFR 15.249 compliance. Not only do these tests and retests take months to pass, they can also be quite costly.
The answer to spending months in design and certification work is a predesigned module. Using a pre-certified module changes your classification to that of an “unintentional radiator.” This classification decreases the time and intensity of the certification phase of the IoT engineering timeline. This is because module providers invest in the certification process for you, often shaving four to six months of development timeline.
As you might expect, modules can carry a higher price per unit than a chip-down solution. Despite this, I find that teams that go this route often quickly make up the price difference. Indeed, they start reaping a return on their investment quickly as they aren’t making up for lost opportunity costs. Wireless modules can make the difference between achieving first-mover status or being seen as a “me too.” This is an important point for organizations in the race to bring their IoT product to market as fast as possible at the lowest possible cost.
Future-proof your IoT solutions
The argument I often hear made against time to market comes from engineers who are concerned about developing a category-killer. They want a product that will dominate the market today yet can evolve and dominate over the product’s lifetime. They think their best route is to wait and make sure they have bet on the right technologies and standards. To address that concern, I recommend that organizations look into dual-mode designs, e.g., Bluetooth Low Energy and Thread. Even if you don’t use both modes today, it gives teams room to grow. And it provides a sound foundation from which an engineering team can make a family of products.
Settle on a standard set of technologies and this will allow your team to create a platform from which they can create a family of connected products. This in turn enables you to bring future-proof products to market even faster. Moreover, it makes it easier to address build of material costs and inventory management. Last, I recommend that product design engineers make sure they plan for:
- Adequate RAM
- I/O for future apps
- International, country-specific requirements
Wireless design is challenging and important to get right. While speed to market is critical, a strong technical foundation is also vital to developing a category-killing, future-proof product. Avoid underestimating the time and effort required to build a robust, certified wireless infrastructure, and consider the use of pre-certified modules. They will help you reduce risk and begin winning business for your new IoT device today.
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