What’s the Future of WiFi for the Internet of Things?

May 22, 2018 Altium Designer

 Holding a phone and texting.

 

I’ve come to adopt several different modes of communication between the different social circles in my life. Slack, messenger, texting, calling, letter writing and various other messenger services - all of which are unique to particular people or friend groups. Most of the time, I can barely keep track of them all and more often I end up sending the right text to the wrong person.

 

IoT protocols are just as diverse, and new options come out frequently. Depending on whether you want long range, like LoRa, or low power consumption, like Bluetooth low energy, IoT protocols are being designed to meet increasingly stringent design requirements. What if you want to stick with an old standby, like WiFi?

Where to Use WiFi for IoT devices

WiFi is most commonly used for IoT devices that are in household or commercial areas where a WiFi network would already be present. Unsurprisingly, applications like agriculture, forestry, or industry aren’t usually a great choice for WiFi. Just like you wouldn’t be able to make a Skype call from the middle of most cornfields, your IoT devices probably can’t count on a WiFi connection either.

 

If you’re designing IoT sensors for an area that already has a WiFi network deployed, like some sugar cane plantations, then WiFi is a great and obvious choice. Otherwise, you should consider cellular or other types of long-range network options.

 

Smart city skyline with WiFi connectivity

WiFi is a great option for IoT connectivity in areas that already have networks in place.

What are the Range and Power Requirements for WiFi?

WiFi is definitely not the lowest power communications protocol, but modules have come a long way. There are pre-certified modules with average currents of 200 𝜇A, although transmit and receive powers are much higher at tens or hundreds of mA. Compared to something like Bluetooth low energy, with standby currents of ~1 𝜇A, WiFi might sound very power hungry; however, if you’re in a household setting where you don’t have to maximize battery life for months or years, then WiFi is a more feasible option.

 

After accessibility and power, range is usually the biggest driver of IoT network selection. WiFi is a moderate range option. Many proprietary options like LoRa and SigFox and standards-based cellular options like LTE have long-range coverage. WiFi is a moderate range, though usually longer range than Bluetooth. WiFi on 802.11ah networks has a much longer range, though not yet widely adopted.

Don’t Forget About Security for IoT Devices

Regardless of your IoT application, you’ll want to ensure that the data you’re transmitting is secure. In some ways, the wide adoption of WiFi makes security more difficult, because the networks are usually easy-to-access. However, security in IoT modules is constantly being improved, with a secure boot to keep only authorized firmware running on the devices. Secure links and connectivity, with appropriate encryption, also provide protection to data.

 

As a hardware designer, it’s easy to assume security is strictly a software or module selection problem, but there are plenty of ways for the hardware itself to be accessed, regardless of your network selection. Make sure your hardware is designed to be secure so that unauthorized devices can’t be paired with your network or a secure debug mode can’t be accessed by nefarious parties.

 

A spy listening in on a business call.

Security is a critical consideration for an IoT application, regardless of the network you use.

Ease of implementation

WIth moderate range and higher power consumption, WiFi might not sound like the best option based on numbers alone. However, using WiFi for your IoT network means that implementation is much simpler than many of the other options. WiFi is cheaply accessible, meaning you don’t have to deploy custom connectivity solutions. It’s also high throughput, so larger data packets, like pictures, aren’t an issue.

 

Many applications, like security, home automation, asset tracking, or patient monitoring are great fields for WiFi usage in IoT, without the added complexities of cellular network access, or adding expensive receivers to local cell towers.

 

Keeping track of all your communications options can be tricky. There are so many, and new ones are always showing up, both in IoT and your personal life. However, WiFi is well-established and here to stay. New standards are being added, but there’s a lot of back-compatibility, which is important if you want your products to be used for a long time.

 

Designing high-quality IoT products requires a lot of factors to be taken into consideration, so it’s worth it to use networks and design tools that are tried-and-true. Altium Designer can’t pick your network for you but it can do just about everything else from helping you manage your modules, from the PCB footprint to supply chain management.

 

If you’d like to know more about how using the right PCB design software can impact your IoT device designs, talk to an expert at Altium today.

 

About the Author

Altium Designer

PCB Design Tools for Electronics Design and DFM. Information for EDA Leaders.

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