Cell tower against a sunset
Cell tower

Cellular technologies like 4G LTE provide the bandwidth and the reliable and secure communications necessary for companies across all industries to take advantage of smart, connected devices. Businesses building cellular IoT products must choose the cellular technology that best meet their requirements, but the alphabet soup of cellular standards for IoT devices can cause confusion. 

In this post, we will explain the different cellular technologies, including the two latest: LTE-M and NB-IoT. We’ll highlight the benefits of each, explore the future of 5G networks and examine how it will impact your current and future cellular IoT deployments.  

What is LTE, and How Does It Differ from 3G?  

LTE, which stands for Long Term Evolution, is a 4G (fourth generation) wireless broadband standard. It can be up to 10 times faster than 3G networks with theoretical 50Mbps upload and 150Mbps download speeds.

Besides faster throughput, LTE offers much lower latency than 3G, which means less network delays or lag times. LTE uses less power, so it’s more power-efficient. It also offers better signal penetration than 3G, so indoor coverage is much improved. 

In contrast to 3G, LTE networks are also more flexible and upgradable, allowing carriers to support newly developed standards geared for specific IoT uses, such as LTE-M and NB-IoT. LTE infrastructure are built with software-defined radios. While carriers use their LTE networks predominantly for consumer needs, they carve out a portion of the spectrum for IoT-specific uses. 

Because LTE is software-defined, the networks can evolve over time. LTE’s proposition is that carriers can install software upgrades to support new cellular standards, including LTE-M, NB-IoT.

When it comes to adoption, LTE is widely deployed and serves as the de facto standard when it comes to cellular communications in the U.S. and most of the world. In fact, in the U.S., carriers have announced plans to phase out their 3G networks as they shift their focus to building 5G networks.

3G networks still have a sizeable market share in some parts of the world, such as the Middle East and Africa, Southeast Asia, Latin America and Central and Eastern Europe. But carriers in those regions are moving rapidly to LTE.  3G can still be beneficial to IoT fleet operators as a fallback connectivity option, but won’t be the main method of connectivity moving forward.

What IoT Standards Fall Under LTE?

The 3rd Generation Partnership Project (3GPP) standards organization has developed two new IoT-specific standards for LTE networks: LTE-M and NB-IoT, which stands for Narrow Band Internet of Things.  Despite the name of the 3GPP, this organization is responsible for both 3G and 4G/LTE standards worldwide.

More recently, 3GPP introduced Cat-M1, which is an LTE-M standard, and Cat-NB1, an NB-IoT standard, that are designed for low power consumption and IoT devices with low-bandwidth needs. 

Cat-M1 and Cat-NB1 were created as part of Release 13 of the 3GPP’s LTE standard for cellular communications. Both are low-power, wide area network (LPWAN) technology that operate on the licensed spectrum and serve as an alternative to unlicensed spectrum LPWAN options, such as SigFox, LoRa and RPMA, which have gained an early lead in new IoT deployments that need low power and long battery life.

As a result, IoT developers currently have four main LTE technologies to choose from to address the growing demand for IoT: Cat-M1 and Cat-NB1, which are starting to be deployed by carriers, and two older, but still current technologies, Cat-1 and Cat-4, that are part of Release 8 of the 3GPP standard and are more widely available today. Let’s take a closer look at each category.  

ublox LARA-R202 is a Cat-1 LTE modem, on a Mikro Elektronica board
ublox LARA-R202 is a Cat-1 LTE modem, on a Mikro Elektronica board

Differences Between LTE IoT Device Categories

Cat-M1 and Cat-NB1 are similar in that they are both low-cost technologies and perfect for low-power, low-throughput IoT applications. They provide improved in-building coverage in comparison to other existing cellular technologies. Battery life can last 10 years. 

There are tradeoffs between the two categories so there are several parameters to consider when choosing a technology for your IoT deployment.

Cat-M1 or LTE-M

The technology offers faster bandwidth speeds and lower latency than Cat-NB1, reaching up to 1Mbps upload and download speeds and latency of 10 to 15 milliseconds.

Unlike Cat-NB1, Cat-M1 supports voice, allowing companies to add voice features to IoT applications such as medical alert devices and alarm systems. Cat-M1 also supports mobile applications, such as asset tracking and wearables. In addition, Cat-M1 has enough throughput to transfer firmware and security updates to IoT devices, which Cat-NB1 can’t do.  

Cat-NB1 or NB-IoT

This technology features uplink speeds of 66kbps and download speeds of 26kbps and a higher latency of between 1.6 to 10 seconds. So it’s best suited for IoT applications that require small, intermittent data transmissions where latency doesn’t matter.

Cat-NB1 doesn’t handle cellular tower handoffs, which is the ability to maintain a cellular data session when the device transitions from one tower to another. As a result, NB-1 is well suited for stationary, low-bandwidth IoT applications, such as smart meters and field sensors. 

Cat-NB1 technology offers longer range support, better signal penetration and consumes less power than Cat-M1. So it provides very long distances and is good for indoor usage. 

LTE also offers Cat-1 and Cat-4, which are IoT categories that handle higher speeds. They are a perfect fit for companies that need fast connection speeds and lower latency. 

Hologram's guide to LTE variants
Hologram's guide to LTE variants


This standard offers 5Mbps upload and 10Mbps download speeds and latency of 50 to 100 milliseconds. It provides much better performance than its newer Cat-M1 and Cat-NB1 counterparts, but it also consumes more power.  


This standard reaches 50Mbps upload and 150Mbps download theoretical speeds, which are essentially the same speeds consumers get on their smartphones. Cat-4 is popular among IoT deployments, but it consumes more power and is more complex than Cat-1.

What LTE IoT Category Should You Choose? 

The four LTE IoT categories have overlapping features and performance metrics. The best choice for your company depends on the amount of throughput you need, latency requirements, power consumption, battery life, cost and how widespread its adoption is by carriers.

Analyst firm ABI Research predicts that by 2026, NB-IoT and LTE-M (Cat-M1) will make up 60% of the 3.6 billion LPWAN connections. But carriers are just starting to adopt Cat-M1 and Cat-NB1.  

Carriers throughout North America, Europe and Asia are adopting one or the other, but because they are complementary technologies, many carriers will choose to support both in the next few years. For example, several large U.S. service providers launched nationwide Cat-M1 netw orks in 2017 and then rolled out nationwide NB-IoT networks in 2019. 

Among the new LTE categories, Cat-M1 and NB-IoT are the most nascent options for companies that have to upgrade their existing 3G IoT deployments as carriers shut down their 3G networks. 

Cat-M1 targets IoT applications that need more frequent data transfer and lower latency than what NB-IoT offers (although these are much less as compared to other LTE categories, such as Cat-1). Cat-M1 costs are currently lower than comparable 2G/3G modules. Good use cases for Cat-M1 include asset tracking, wearables such as fitness bands and smart watches, and patient monitors.

Cat-NB1 is targeting stationary use cases such as smart gas, water and electricity meters, smart street lighting and parking sensors, HVAC control, industrial monitors and agricultural sensors that can monitor irrigation systems and detect leaks. 

Because Cat-M1 and NB-IoT networks are still getting built, Cat-1 and Cat-4 are your best bets if you need to deploy IoT on LTE today. Cat-1, for example, has large international support.

Cat-1 networks can handle from low to medium-bandwidth applications, from 100Kbps to a few 100Mbps of data per month. Use cases include smart meters, video surveillance, fleet management, as well as digital signage, point-of-sale terminals, retail kiosks, ATM machines, connected healthcare and consumer electronic devices. 

Cat-4 networks are good for IoT devices that aggregate data streams such as network bridges and IoT gateways. Companies can also use Cat-4 for video surveillance, in-car hotspots and in-car infotainment. 

Drone flying next to radio antennas
The future of 5G cellular unlock low latency communication for new applications like long distance drone delivery and monitoring.

5G On The Horizon: How Next-Generation Network Affects Your Current IoT Deployment

5G is coming, and it promises blazing fast communication speeds and extremely low latency. But 4G LTE won’t go away for at least several years, so if you need to implement IoT today, you can do it with LTE IoT technology. Here, we will first explain the 5G benefits, its timeline for construction and why 4G LTE is the way to go if you need to deploy IoT in the next few years.  

The 5G specification calls for theoretical uplink speeds of at least 10Gbps and download speeds of at least 20Gbps. The 5G specification also sets a maximum latency of 4 milliseconds and a latency of 1 milliseconds for ultra-reliable low latency communications. That compares with 20 milliseconds latency with LTE today

5G will provide the infrastructure necessary to handle the real-time video and artificial intelligence algorithms necessary to support autonomous vehicles and applications that require fast network performance, such as remote surgery in healthcare and remote management of hazardous machinery. 

While carriers are racing to build 5G systems, it’s still very early days. 5G is extremely short range technology. To achieve the high bandwidth and capacity necessary to handle a large number of users, carriers will have to install 5G base stations on every block or every few blocks. In contrast, 4G LTE requires cell towers every mile or every few miles. 

Municipalities are wrestling with 5G deployment and the permitting processes to enable its construction. This process will take a few years in cities and much longer in rural communities. As a result, LTE will still remain the de facto standard for several years at least. 

The upshot: for companies that need to do any type of IoT deployment in the U.S. or internationally, LTE will provide the most extensive and thorough coverage over the next two-plus years. 

Besides, the vast majority of IoT applications don’t require the fast speed and low latency that 5G offers. In most cases, LTE offers the features and performance you need. Also, 3GPP plans to evolve LTE-M and NB-IoT standards and merge them into the 5G standards, so the two newest LTE IoT technologies are not going away. LTE-M and NB-IoT will co-exist with 5G, so in the future when 5G is the dominant cellular network, companies can still leverage their LTE investments.

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