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Dec, 10 2020

Cellular IoT: What Business Leaders Should Know

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Cellular IoT uses cellular networks to connect physical devices to the Internet. This connection enables these devices to transmit and receive data, making them part of the “Internet of Things” (IoT). Cellular IoT is the most popular type of IoT connectivity, primarily because it:

  • Provides excellent coverage
  • Simplifies global deployment
  • Works right out of the box
  • Establishes a more secure connection than other shared networks
  • Performs well in mobile, indoor, and outdoor applications
  • Supports low and high bandwidth

Like smartphones and other mobile devices, cellular IoT relies on 2G, 3G, 4G, 5G, and Low Power Wide Area Networks (LPWAN) technologies LTE-M and NB-IoT to transmit and receive data. The advantage of using these mobile networks to connect devices is that they’re everywhere—you just have to connect to them. This allows manufacturers to maximize coverage, maintain stable connections on-the-go, and with LPWAN to optimize the battery life of their IoT devices.

For manufacturers building IoT devices, cellular IoT is one of the most reliable and accessible ways to enable Internet connectivity. If you’re considering using cellular IoT, there’s more to unpack—and a lot of acronyms you’ll need to be familiar with. 

In this guide, we’re going to explore:

  • What cellular IoT is used for
  • How cellular IoT connectivity works
  • The types of mobile networks IoT uses
  • Alternatives to cellular IoT
  • Why redundancy is critical for cellular IoT
  • Cellular IoT security

You should come away feeling equipped to talk about cellular IoT with colleagues, so you can decide if it’s right for your application. Let’s start by looking at what manufacturers tend to rely on cellular IoT for.

What is cellular IoT used for?

Someone cuts the power to a private facility, disabling the WiFi-based alarm system. They break into the building, unaware that the alarm system has a backup cellular connection, triggering an alert to the building owner through an app on their phone. Battery-powered security cameras detect the motion and automatically start uploading footage to the cloud, where the owner can view it remotely. 

A utility provider places thousands of smart meters throughout the area they serve, then monitors resource consumption in real-time—without ever sending a technician to read the meters.

Multiple firefighters are suppressing a raging wildfire over a large area. The crew is scattered, but a single leader tracks the exact location of each team member and sees what they see, enabling them to accurately assess risks and allocate resources.

These are just a few examples of how cellular IoT is shaping the way we engage with the world today. It's not just about smart, cool gadgets—sometimes it's a matter of life or death.

Cellular IoT is well-suited for a wide range of applications in indoor and outdoor settings. It’s used in everything from self-driving cars to smart parking to autonomous farming equipment to consumer devices like smartwatches. In fact, cellular IoT is so widely used that if a device is being used in a B2B application (where the end user depends on having a reliable connection), it probably relies on cellular connectivity.

More broadly, cellular IoT is ideal for logistics, manufacturing, asset tracking, supply chain management, emergency services, healthcare, and security. Cellular IoT devices can transmit and receive signals from any point in the world to any other point in the world. Since Mobile Network Operators (MNOs) have already built vast networks designed to maximize coverage, cellular connectivity allows manufacturers to deploy a single iteration of their device to almost anywhere. And with 5G networks, they can even make real-time data transfers while moving at high speeds.

The biggest limitation with cellular connectivity has always been battery life and power consumption. But low power wide area networks (LPWANs) and advances in technology make it possible for cellular IoT devices to save power when not in use, and modern cellular sensors can transmit small packets of data without consuming much power. 

How cellular IoT connectivity works

Cellular connectivity depends on several key components. If you’re trying to get a better grasp of cellular IoT, you’ll want to get familiar with basic concepts like SIM cards, modems, frequency bands, and the mobile network classifications (2G, 3G, 4G, 5G, Nb-IoT, LoRaWAN).

Cellular IoT connectivity

IoT SIM cards

Like smartphones and other mobile devices, IoT devices need a SIM card to connect to a cellular network. But unlike your smartphone, you don’t want your IoT device to be limited to a specific cellular provider’s network. If your SIM card only connects to Verizon, America Movil, Deutsche Telekom, or China Mobile’s network, then your device’s range is limited to that provider’s coverage. 

This is one of the reasons why redundancy is so vital for cellular IoT. Manufacturers that want to utilize cellular IoT connectivity should plan to use SIM cards that are network agnostic, meaning they work across any cellular network. This allows the devices to connect to whatever network has the best coverage in a given area and ensures that if one network goes down or experiences a sudden lapse in coverage, the device can stay connected via another network.

EMnify’s SIM cards, for example, enable your device to connect to more than 540 cellular networks in over 180 countries.

Modems, modules, and chipsets

While the SIM card you choose determines which cellular provider’s networks you can access, the modem you select impacts which network types and frequency bands your device can connect to. Using a modem simplifies the IoT development and certification processes, but it costs more per unit than buying the raw components required to create a custom solution.

In most cases, you want to go with a modem. 

Starting with more basic components like a chipset (which come built-in when you choose a modem) may sound appealing because it lowers your cost per device, but it also drastically increases your time to market and development costs—so the total cost of ownership (TCO) is typically much higher. Custom connectivity solutions usually only make sense for manufacturers that don’t have significant time constraints and plan to produce on a scale large enough to offset those added development costs. (You have to produce hundreds of thousands of units to make starting with a chip set result in a lower TCOf.)

Frequency bands

A frequency band is a range of frequencies within the radio frequency (RF) spectrum, which goes from 30 hertz (Hz) to 300 gigahertz (GHz). Cellular uses a fraction of the spectrum between 800 MHz and 5 GHz for 2G, 3G, and 4G connections. 5G can use bands up to 35 GHz. 

While there are only a handful of cellular network types, each has multiple frequency bands, and different carriers and countries may use different bands. Within 4G LTE alone, there are 27 bands.

For most IoT manufacturers, this is one of the most confusing aspects of cellular connectivity.

Your IoT device can only operate within the bands your modem supports and for which it is certified. So it’s vital that you consider the countries you want to deploy in and the cellular carriers you plan to work with, so you can select a modem that’s compatible with the bands they use. 

It’s also helpful to think about the environments your device will be used within. Lower frequency bands have wider coverage, which increases the range your device can work within. Buildings, tunnels, and other large structures are also less likely to interfere with signals you transmit on low frequencies. But in cities, these low frequencies have lots of traffic because there’s a greater number of devices using them, so higher frequencies can have less interference.

Thankfully, modems can support multiple bands. In the future, most cellular IoT applications may use specialized mobile networks like Nb-IoT or LTE-M, which have modems that work globally in all frequency bands.

The advantage of cellular connectivity

Cellular networks have several key factors that make them so popular with IoT manufacturers. When it comes to convenience, coverage, and security, it’s hard for other connectivity solutions to compete with cellular.

Global coverage

For large-scale, global deployments, cellular M2M connectivity is generally considered the most reliable and beneficial connectivity method. You don’t need to build new infrastructure for every new deployment—you just have to connect to a network that’s already in place. As you deploy in new countries, your cellular provider may have roaming agreements with another carrier that covers that region. If not, you can select a new carrier with local coverage but then have to adjust your logistics process to make sure the right SIM gets to the right country. 

Cellular is a WAN (wide area network) with the long-range ability to connect globally using radio waves that are sent and received via cell towers. In comparison, WiFi connectivity requires your device to remain much closer to the access point/router, preventing long-range mobility. Similarly, Bluetooth connectivity is also short range, requiring your device to be within 10–100 meters of the access point, depending on the power-class.

Built-in authentication

Cellular networks use SIM cards to authenticate devices, associate them with a legitimate subscriber, and provide secure connectivity. Hackers can spoof IP addresses, but they can’t spoof a subscriber’s identity, which is stored on a SIM card.

Secure connectivity

When your device connects to a customer’s WiFi, it shares the connection with all the other devices on the WiFi network. If these devices have a security issue, it puts your devices at risk—and the inverse is true, too. Connecting to a cellular network keeps your devices separate from your customers’ other Internet-connected devices. Manufacturers need to take IoT security seriously, and cellular connectivity gives you a number of security advantages, starting with the network your devices connect to.

Types of mobile networks cellular IoT uses

Over the years, cellular networks have grown exponentially faster and more powerful. But for IoT manufacturers, power and speed usually aren’t the main factors to consider. Later-generation cellular networks can mean greater power consumption and less coverage, too. The network you plan to use will impact your device’s range, coverage, frequency, power usage, modem size, cost, and longevity.

Most people have at least heard the terms 2G, 3G, 4G, and 5G networks, but you may not know much about the differences between them. To accommodate the needs of most cellular IoT devices, cellular carriers have also developed other network types that may sound less familiar, such as Nb-IoT and LoRaWAN.Generally speaking, the more advanced a network is, the more power connected devices will consume while in “idle mode”, but the less power they’ll consume to download or upload large amounts of data. More complex networks also tend to have more expensive modems.

Here’s a quick explanation of each network type as it relates to IoT development. (For a more technical comparison, check out our whitepaper, An Introductory Guide to Wireless IoT Connectivity.)

Download the Guide for Cellular IoT Security

2G networks

Second-generation (2G) mobile networks have been around for about three decades. This is the scaffolding much of our cellular communication was built on. It gave people the ability to send text messages, picture messages, and multimedia messages. 

In cellular IoT, 2G networks have worked well for logistics, telematics, and supply chain management applications because they allow devices to transmit basic alerts, status updates, and location data while using very low power. 

But 2G networks will soon be a thing of the past. Cellular carriers are beginning to shut off 2G networks to free up bandwidth for 4G and 5G networks. Some 2G networks have already gone offline, and many of the largest cellular carriers around the world are in the process of sunsetting theirs. As carriers continue to phase out their 2G networks, IoT devices that depend on them will become obsolete—unless they’re compatible with other networks.

3G networks

3G cellular networks built on the capabilities of 2G technology, providing faster data transmission, and enabling mobile devices to connect directly to the internet. This came with a  downside: 3G networks use 50 percent more power than 2G networks.

Like 2G, 3G has been used for things like logistics, telematics, and supply chain management. But it can also facilitate more advanced processes like file sharing, streaming, analytics, and remote device management. This has made it ideal for consumer IoT devices and smart grids.

But 3G is on its way out the door, too. The transition isn’t as far along as the shift from 2G, but it will likely happen within the next few years. IoT applications built on 3G networks won’t last long, and many companies that rely on IoT devices are already aware that this change is underway—so they’re looking for devices that use 4G or low power wide area networks (LPWANs).

4G LTE networks

4G LTE (long term evolution) is capable of data speeds more than 10 times faster than 3G, and it’s the world’s leading mobile network technology. 4G LTE technology enables devices to make low bandwidth voice calls (this is known as voice over long term evolution, or VoLTE), utilize video conferencing, and facilitate closed circuit television (CCTV).

Since 4G LTE allows devices to upload and download data at much faster speeds, it works well for IoT applications involving video transmission, such as security cameras. It’s also widely used in healthcare and car entertainment systems. In auto racing, teams use 4G connectivity to transmit immense amounts of data from race cars to engineers.

4G LTE connectivity uses more power than most IoT processes need (50 percent more than 3G connectivity), but a range of power saving features can make it a viable option.

5G networks

5G is the future of IoT. But it’s not really how we use IoT in the present. While cellular carriers are rolling them out all around the world, 5G networks don’t have very widespread coverage yet. Even by 2025, they’re only projected to represent about 15 percent of total mobile connections worldwide. 

This technology has a lot of potential for IoT, particularly for mobile, data-intensive applications where speed is crucial—like self-driving cars and emergency services. 5G networks can offer nearly real-time data transmission, and they can maintain a stable connection with devices moving at very high speeds. And while more advanced networks have typically demanded more power, 5G networks can support cellular connectivity with low power consumption.

At the moment, there are very few modems that can facilitate 5G connectivity, and they are far more expensive than other options.

But as carriers phase out their 2G and 3G networks, that doesn’t mean IoT manufacturers are stuck choosing between too much power consumption and too little coverage. Cellular connectivity has evolved new solutions to accommodate the needs of most IoT applications.

Low power wide area networks (LPWAN)

Decades ago, traditional cellular networks made it possible for cell phones to send texts, connect to the internet, and transmit more advanced data, opening the door to cellular IoT connectivity. 

But those networks weren’t designed to accommodate the massive influx of new devices that would need to share bandwidth. Their primary purpose was voice communication, and they were optimized for creating spontaneous connections. They’re always checking for incoming calls, actively listening to radio signals, and sending periodic tracking area updates (TAUs) to let the network know where they are. This is why traditionally connected devices consume so much power even when they’re not in use—and it’s why extending battery life has been such a struggle for smartphones.

Most IoT devices don’t use cellular networks that way, and these unnecessary updates consume too much power.

For the vast majority of IoT applications, manufacturers want to maximize coverage while reducing power consumption and costs. In recent years, cellular providers have deployed new low power wide area networks (LPWANs) to meet the specialized needs of IoT applications. LPWANs allow IoT devices to transmit or receive updates at fixed intervals or in response to an external trigger (such as a sensor), rather than maintaining a continuous connection. This drastically decreases power consumption. 

There are two main types of LPWANs IoT manufacturers should be familiar with for cellular connectivity.

Narrowband-IoT (Nb-IoT)

Narrowband-IoT takes advantage of gaps in the radio frequency spectrum to provide more efficient connectivity and prevent interference. These unused frequency bands are known as “guard bands.” While cellular networks like 4G LTE use broadband connections (which support a wide range of radio frequencies), narrowband connections isolate devices to “narrower” ranges.

Narrowband-IoT introduces two major power saving features: power saving mode (PSM) and discontinuous reception (DRX). PSM essentially puts the device to sleep when not in use, and DRX can extend the period of time that the device isn’t “actively listening” for a signal. As a result, devices that rely on Nb-IoT can have years of battery life. And since Nb-IoT was designed for the Internet of Things, it works on all frequency bands. You don’t need different modems for different regions, so global connectivity is both simple and cost effective.

Nb-IoT is ideal for indoor applications or environments with a large volume of connected devices. It’s typically used in asset tracking, smart city applications (like smart meters and traffic lights), and alarm systems, where data transmissions are intermittent and don’t require high download or upload speeds.

Long term evolution (LTE-M)

LTE-M (short for long term evolution machine type communication) is an offshoot of LTE technology that’s specifically designed for the Internet of Things. It lets IoT devices connect to 4G networks, giving them more bandwidth and mobility than Nb-IoT, as well as access to voice over long term evolution (VoLTE)—a more advanced voice service. However, it comes at the cost of more idle power consumption and more expensive modems.

In spite of the greater power usage, LTE-M can still leverage PSM and DRX to significantly extend a device’s battery life, enabling it to work well for many of the same applications as Nb-Iot while also enabling more functionality.

When a device needs to transmit or receive a larger volume of data, LTE-M uses less power than Nb-IoT because the higher bandwidth allows it to upload and download data significantly faster. This helps “future proof” IoT devices because firmware upgrades may introduce new functionality that requires greater data consumption.

Note: If you hear someone talk about eMTC (enhanced machine-type communication), that’s part of LTE-M.

Comparative Table

So which network type should you use?

As you can tell, choosing the right ideal network type for your application can be confusing. You want to maximize availability and battery life while also getting the processing power you need. Our IoT experts can help you find the set up that’s right for your application. 

Connect with a cellular IoT expert today.

Alternatives to cellular IoT

Cellular IoT is highly versatile, but it isn’t right for every application. And it’s not the only connectivity option manufacturers have. Some applications might be better suited for short-range connectivity solutions, such as Wi-Fi, Bluetooth, or Zigbee. It’s also fairly common for manufacturers to build-in multiple connectivity options to give their IoT devices more flexibility.

Wi-Fi IoT

Wi-Fi networks can handle large data transfers over distances of around 100 meters or less. For indoor, data-intensive applications, this can be a suitable connection for IoT devices. However, transferring data over Wi-Fi uses more power than it does over a cellular network, so this isn’t ideal for battery-powered devices.

Unlike other connectivity options, Wi-Fi puts the burden on the manufacturer or the end user to maintain and scale their network. The more IoT devices a company or consumer connects, or the more data-intensive processes they use, the more strain it puts on the Wi-Fi network.

Whoever facilitates the network takes on greater liability and has to invest in IoT security. Additionally, setup becomes more complicated—each individual device has to be manually connected to the network.

Bluetooth IoT

Bluetooth connections work well for short-range devices with low data usage, particularly in environments with lots of interference. Bluetooth signals are weak and the devices need to be close together (usually within 10 meters or less), but Bluetooth connectivity can work well for some specialized indoor applications.

Zigbee IoT

Zigbee is another low power, low-bandwidth wireless network. Like Bluetooth connections, Zigbee connections have relatively limited range. However, interconnected Zigbee devices can create a “mesh” which allows them to relay data to and from other devices in the mesh. So the network’s range is really dependent on the placement of its connected devices. Zigbee connections are often used in smart homes, but they work for some medical, scientific, and industrial applications with low data usage as well. 

Long Range Wide Area Networking (LoRaWAN)

LoRaWANs are a type of low power wide area network (LPWAN) that doesn’t rely on cellular connectivity. Devices connected via LoRaWAN operate on license free frequencies, which means if you use your own gateway and server, you won’t be charged for data usage. Typically though, you’ll use a third-party network server or network management tool which will charge a subscription.

This type of connectivity is ideal for remote applications like mining, farming, renewable energy, and supply chain management, which are often too remote for other types of connectivity. However, LoRaWANs can only transmit for 30 seconds at a time, and they can facilitate a maximum of 10 downlink messages per day—so the actual use cases are pretty limited.

Why redundancy is critical for cellular IoT

If your IoT device loses its connection, it can’t do what it was designed to do. And regardless of what causes the failure, the end user isn’t going to blame the cellular carrier, a third-party data center, or the manufacturer of a specific component. They’re going to blame you.

That’s why redundancy is an essential component of cellular IoT. If you have a backup plan for every failure, you can maximize service availability and reduce the impact of network-related problems. 

For IoT manufacturers, it’s important to build redundancy into your application, but you’ll also want to look for connectivity providers that design with redundancy in mind.

Network redundancy

Standard SIM cards are confined to a single Mobile Network Operator. If your SIM card only works on AT&T’s network, and AT&T has poor coverage in the area your device is located, it’s going to disrupt your service.

SIM cards that are designed for IoT are network agnostic, meaning they can connect to any cellular company’s network. So regardless of the country you deploy in or the operator that serves a particular area, you can connect to the network that has the best service in that area—and switch networks if the device moves into an area where another carrier has better coverage.

Of course, it’s also important to consider which frequency bands your modem can connect to, particularly when it comes to 4G LTE, where different countries and companies use different bands.

Software redundancy

Any software your service depends on needs to have multiple microservices that can process critical functions. That way, if one of them fails, there’s always another available to take over and prevent service interruptions. Instead of having a single service dedicated to key network functions, for example, using multiple microservices ensures that there are several that can handle crucial responsibilities.

Infrastructure redundancy

If your entire infrastructure depends on a single availability zone for a data center, you’re in trouble. Your devices will only stay connected as long as that data center remains available. By being available in multiple zones, you ensure that your devices always have a fallback if a data center goes down—so your users have uninterrupted service.

Cellular IoT security

Connecting to the Internet will always create security challenges. Since IoT devices often have sensitive data, it’s important to think about how you’ll protect your customers and how various connectivity options impact your device’s vulnerabilities.

Cellular connectivity has several advantages for IoT security:

  1. The devices don’t share the network with the end user’s other devices, so they can’t infect each other or be infected by a hacked computer on the company’s WiFi.
  2. Manufacturers can remotely access the device via VPN without exposing a public connection.
  3. The Mobile Network Operator can securely authenticate the device through its SIM card.
  4. Cellular network firewalls can limit a device’s connectivity to its core functions.
  5. A connectivity management platform makes it easy to monitor activity and detect anomalies across all locations.

If you need to roll out firmware updates, cloud platform providers offer remote device management services, and cellular networks have enough processing power to transmit these updates.

Remote access makes it possible for manufacturers to troubleshoot IoT devices locally or in the field, but it also makes those devices vulnerable to hacking. Virtual private networks (VPNs) let you create secure connections to your devices, but if you’re using WiFi to facilitate your IoT connectivity, this becomes a lot more challenging—you’ll have to manage different VPNs for different customer locations. With cellular connectivity, you can give each device a private static IP address, which lets you manage all devices across all customer locations with a single VPN.

If a hacker compromises a WiFi-connected IoT device or a computer on the same WiFi network, they can use it to access other devices it’s connected to. With cellular IoT, you can use a cellular network firewall to ensure each device won’t become a doorway to the others.

There’s a lot to consider when it comes to IoT security. For starters, check out our free guide.

Is cellular IoT right for your business?

For IoT manufacturers, cellular connectivity offers several huge advantages. If your devices require global coverage, mobility, low power connectivity, or high data throughput, cellular networks may be your path to the Internet of Things.

Talk to one of our cellular IoT experts today. We’ll help you talk through your options and navigate your application’s unique connectivity needs.

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