Cellular and WiFi are the two most popular connectivity methods for IoT technology. Though many early IoT projects relied on WiFi, cellular technology has grown in popularity as it became better equipped to handle more use cases.

Against the backdrop of continuous innovations in the wireless industry, choosing the best radio access technology for your IoT project has become challenging.

In this article, we'll examine the key differences between cellular and WiFi, show example use cases for each one, and explain how you can choose the right technology for your project.

There are several criteria you can use to compare cellular vs. WiFi, such as:

• Cost
• Reliability and security
• Location detection
• Coverage
• Data throughput
• Device provisioning

Let’s dig into the details of each one to understand how cellular and WiFi are meaningfully different (or in some cases, similar).

Cost

Cellular data plans are generally more costly than comparable WiFi plans on a per-byte basis. If your project requires recurring big data transfers, WiFi networks would be your best choice.

However, when doing a cost comparison, you should factor in ongoing cost of maintaining your WiFi network as well as the cost of provisioning many devices across different WiFi networks that you as the IoT fleet operator may not control.

"Cellular is more expensive on a per device basis than WiFi," said Calvin Jepson, senior manager of solutions architecture at Particle. "But during that comparison, you should also take into account the cost of maintaining and managing the WiFi network as a part of the per-device cost."

When comparing one time hardware costs, cellular modems are more expensive than WiFi modems. That said, it’s important to understand how either type of connectivity will influence the total cost of ownership of your IoT deployment.

Reliability and Security

Part of what you’re paying for in your cellular plans is world class security and reliability. While it is possible to create comparable security and reliability over WiFi, you're relying on WiFi network owners & building management teams to do that work on an ongoing basis. In contrast, cellular security is backed by knowledgeable cybersecurity specialists.

“When you're buying cellular, part of what you're paying for is that expert network management," Calvin said. "When you're buying WiFi, you have to figure out WiFi network management yourself. If you're connecting to your own WiFi network, generally speaking, that provides a less stable network than the cellular solution does."

Location Detection

There is not much difference between getting accurate location information via WiFi and cellular. However, in some circumstances where your device is out of range of WiFi, cellular networks will perform better, being able to mark your devices’ approximate location. In either case, getting location from WiFi SSIDs or cellular towers requires integrations with 3rd party providers which give location estimates based on a geographical database of network IDs.

Learn how Particle’s Location Fusion technology gives you the best of both worlds.

Coverage

WiFi is a great access technology when your deployed environment has WiFi coverage. This tends to be the case for devices deployed in homes or buildings, or in places where cellular networks are known to not have coverage such as oil rigs and mines. If you’re planning to track things that are mobile, such as vehicles, or deployed in remote locations, then cellular is better.

Although this is covered below, it bears repeating that cellular is often a great choice for stationary assets in urban and office environments because of the relative ease of onboarding a device to the cellular network compared to a WiFi network where you have to know passwords and get through network specific security measures.

Data throughput

Traditionally, WiFi performs faster than cellular networks. But with the development of 4G and 5G, the data throughput of cellular networks can be relatively on par with WiFi. Both cellular and WiFi networks are sufficient for most IoT projects. The protocols you use to transmit data will also have an impact here. Check out our guide on IoT protocols and standards to learn more.

Device Provisioning & Setup

It’s much easier to deploy fleets of cellular devices when compared to WiFi. Installing a cellular fleet can be as simple as turning on the power to the device. Assuming that connected device has cellular coverage, it will automatically connect to the network.

In contrast, with a WiFi device you may need to first set up your network or otherwise manage access to that network with usernames & passwords for each device. This can be a deal breaker for many use cases where the WiFi network is heavily protected by the owner.

Check out our guide to IoT device management to learn more.

Pros:

• Cellular has more robust privacy and security with automatic encryption.
• Cellular service has more comprehensive coverage with no set range since you don't need a router. This is important for remote assets like oil rigs.
• Obstacles do not as easily block deeper coverage with cellular signals.
• Often better for low-power IoT use cases with low consumption requirements

Cons

• Data plans can be expensive if your use case requires you to send large amounts of complex data.
• Bundling SIM cards from different providers can force you to get your entire IoT deployment recertified. Be sure to understand what goes into FCC certifications for IoT.
• Devices can lose coverage in locations where cellular service is spotty.
• Not always accurate when determining device location.

Pros:

• Private WiFi connections are secure and enable fast access to connecting multiple devices.
• Suitable for data-heavy transfers since there is no cost limitation on the amount of data transferred. A note here is that with the development of 5G, the advantages of WiFi relative to cellular might be eroded.

Cons:

• Public WiFi may not be secure.
• Reliant on end user's WiFi. If they change their password or get disconnected, the device may go down.
• The devices need to have access to a WiFi router. The limited range can be a barrier for remote assets.
• Too many devices connecting to one router may degrade the signal.
• WiFi configuration may require technical expertise.

The use cases for cellular IoT are extensive. In this section, we’ll share a few examples of where it’s effective.

Building Smart Hot Tubs

Leading hot tub manufacturer and distributor, Jacuzzi, is driving innovation in its industry with cellular IoT. Most hot tubs on the market rely on WiFi connectivity. Jacuzzi was able to differentiate and create a superior product by using cellular connectivity.

Jacuzzi realized that most WiFi-based connected hot tubs suffered from weak connectivity. Many customers often have their hot tubs outside, far away from their routers. This meant that the remote control functions couldn’t work due to weak or lost connections.

Another factor was the accessibility to provision. Think about how your cell phone or mobile device automatically connects to the local cellular service when you travel home or abroad. This does not apply to WiFi. Unless you've already connected to the WiFi spot before, what most often happens is that you encounter a situation where it asks you to choose between available WiFi networks, enter the password, and connect.

"It's a much more difficult provisioning process on WiFi than it is on cellular," Calvin said. "For Jacuzzi, what they really wanted was to create a user experience for the installers and owners where it just works when you turn it on. It doesn't matter where you are. If you turn it on, it connects and it works."

Deploying Continuous Emissions Monitoring

Qube was an early mover in response to emissions-cutting pledges that gained widespread attention following 2021’s COP26 conference. Qube offers continuous emissions monitoring solutions by combining proprietary algorithms that can detect greenhouse gas emissions and pinpoint their type and location with IoT sensors that provide a continuous data feed.

Qube was looking for an affordable platform that could scale across the world while offering low power consumption. The team knew that cellular connectivity would be the right choice as many of their devices would be deployed in remote locations where WiFi wouldn’t be available.

Qube built its solution using Particle’s EtherSIM solution, a SIM card powered by over 350 carriers worldwide. No matter where Qube’s devices are deployed, they will automatically connect to the best cellular network available. In other words, Particle’s global cellular connectivity makes Qube’s cellular management unified and straightforward while reaching maximum coverage.

“We rely on Particle’s devices to get continuous data, which is streamed to our servers on a minute-by-minute or second-by-second basis. We then use that continuous data in our machine learning algorithms to infer what is actually happening in terms of leak quantity, leak size, and leak type,” Cube COO Eric Wen said.

Managing Remote Industrial Assets

While the emissions monitoring sector is benefiting from global connectivity, those with industrial IoT applications are also finding key benefits from cellular connectivity.

FieldIntell, a cloud platform serving customers mainly in oil & gas, agriculture, and mining, is also seeing a promising future of stable global-wise cellular connection.

Particle provides global connectivity with hundreds of carriers worldwide, which saves FieldIntell’s time spent on negotiating with carriers across multiple countries. FieldIntell’s customers push Over-the-Air updates and remotely control complex assets with connectivity that’s integrated with both the devices and cloud.

Cellular isn't always the best everywhere. If your devices mostly live in a facility with cement and metal all around it, signals from a cell tower aren't going to reach them. There are other use cases, like oil rigs in the middle of the ocean, where there's no cellular coverage.

Under those circumstances, WiFi can be a superior choice. For example, remote oil rigs or mining operations generally have a satellite uplink and a local WiFi network. The same applies to industries like mining, which are usually based in remote locations where cellular networks haven't invested in putting a cellular tower out there.

There’s no one “best” choice for every single IoT project. Choosing cellular vs. WiFi comes with tradeoffs that have to be understood and managed to find the best option for your deployment.

Here are a few things to consider as you decide which technology would be best for your IoT project.

Device Location and Movability

The first question that you should ask yourself is where your device is going to live and whether it's movable.

"For any device that's moving even a few-hundred feet, you can't use WiFi because it's not going to have access to the same WiFi network across those different places where it needs to operate," Calvin said.

If the device is movable, then cellular connectivity would be your best bet. Key examples here would be IoT-connected light electric vehicles, whether they’re part of a rideshare, privately owned, or used for last-mile delivery.

If the device is going to be part of a mostly stationary asset that will have constant access to a reliable WiFi network, then WiFi can be a good choice as well.

Number of Devices

A high concentration of connected devices may lend themselves to more to cellular connectivity. This is because the more devices connected to a single WiFi network, the more the signal degrades, potentially leading to lost connectivity.

If you have a high concentration of devices in one location, cellular connectivity might be your best bet.

The Desired End-User Experience

If you want to provide a seamless onboarding experience for your customer, you want the device to be instantly connected to the Internet anywhere in the world, cellular would be your top choice.

WiFi requires the end user to set up the network and ensure the device can connect to it. This isn’t a problem if someone with the required technical expertise to do this is present, but can be difficult for those without.

The ongoing 3G sunsetting and introduction of 5G and other advanced technologies is bringing down the cost of cellular connectivity and widening the network coverage. More and more, IoT deployments that were previously impossible to run on cellular due to no coverage or high cost are becoming technically and financially feasible. Cellular will get increasingly more valuable relative to WiFi with the benefits of 5G and technology innovation.

"What we're seeing is that because networks are getting cheaper and coverage is getting better, there are a bunch of use cases that are now possible," Calvin added. "Particle is riding that wave and enabling our customers to have IoT where previously you couldn't."

Security Needs

Protecting your devices from bad actors is critical, especially if downtime or improper usage can lead to injury or equipment failure.

In general, cellular networks offer considerable security advantages. They are encrypted by default, while encryption on WiFi connections must be enabled manually by the network owner. Additionally, security upgrades for cellular-connected devices happen automatically, while security patches must be installed manually for WiFi.

If your devices are going to be connected to a public WiFi network, or if they’ll be connected to a private network that may not be adequately protected by the owner, cellular would be a safer choice.

Particle can give the best of both WiFi and cellular connection by working on the same Device OS operating system. Device OS offers an easy-to-use programming framework that makes it simple to write IoT applications that can connect via cellular or WiFi. It gives you the same interface no matter how you choose to connect to the Internet.

"Whether you build your specific logic for a hot tub, a scooter, or a water monitoring solution, all of that's built on the same software interface called Device OS, regardless of its WiFi or tracker or site. That makes it really useful for customers who have what we call heterogeneous fleets," Calvin said.

“Heterogeneous fleets” have multiple device types. If you’re using Particle devices, you’d be using a mix of the following:

• Argon - a powerful Wi-Fi development kit
• Boron - a powerful cellular enabled kit
• Tracker/TrackerOne - a ready-to-go T SoM (system on a module) carrier board with optional weatherproof enclosure.

A heterogeneous fleet reduces technical debt associated with managing various projects and allows for switching between device/connectivity types for different stages of development.

In some cases, people start by buying Argons since there’s no subscription fee and you can develop firmware and conduct tests easily. Once it's time for them to start building the devices, they can switch from Argon to Boron and use the same code, which is a unique proposition that Particle can offer.

"Imagine you're a novice at squash, and you're a right-hand dominator. To get started quickly, you want to use your right hand. But once you join the major leagues, you have to use your left hand to be competitive," Calvin said. "It’s the same with IoT. You might be great at using cellular or WiFi during prototyping or at a small scale. But when you scale an IoT deployment, you might need to use completely different technologies, redesign a lot of stuff, and redo a lot of the work that you already did to build a scalable solution to be market-ready.”

Particle is a platform that you can use to develop prototypes, and then easily use to scale when you're ready for the big leagues.

Special thanks to Calvin Jepson and Raniz Bordoloi for providing their expertise for this article.