A Deep Dive into IoT Networks: T-Mobile’s NB-IoT & Cat-M1

IoT Networks
Illustration: © IoT For All

It’s no secret that the number of connected “things” in the Internet of Things (IoT) across many industries is expected to continue to explode over the coming years. IoT solves countless problems in needing a secure, reliable connection for many different devices and applications. But with more and more devices coming online, the new problem will be how to keep a reliable, secure connection. 

T-Mobile was the first to release a nationwide Narrowband IoT Network (NB-IoT) in 2018 and recently released its Cat-M1 nationwide network. Let’s look at some of these network solutions for IoT connectivity.

Best Networks for IoT Connectivity

There are a few different options when it comes to IoT coverage. Most IoT networks operate as a low-power wide-area network or LPWAN because IoT connectivity needs to transmit small amounts of data with low bandwidth and long battery life. Some of the most popular options under the LPWAN umbrella include NB-IoT, CATM1, LoRa, and SigFox. Here’s a look at their definitions and what makes each different.


Narrowband IoT (also referred to as NB-IoT) is lower power, LPWAN network built on the 3GPP standard that doesn’t operate in the traditional licensed LTE construct. Its LTE-advanced technology provides a pathway to 5G IoT and offers many comparable benefits like low power usage, long battery life, and low device cost. Some carriers like T-Mobile offer an NB-IoT network for IoT coverage.

T-Mobile was the first to launch NB-IoT in the U.S. and the first in the world to launch NB-IoT in the guard bands. NB-IoT in the guard bands equips efficient spectrum resources utilization and prevents IoT applications from competing with other data traffic for network resources.

Who is NB-IoT For?

NB-IoT is ideal for many smart applications and devices across several industry sectors. Some examples include tracking valuable business assets, optimizing equipment use, ensuring fleet safety and compliance, monitoring waste management and energy utilities, among so many others. These IoT devices allow you to reduce costs, increase productivity, and improve the overall day-to-day of your business operations.


A more recent IoT network option is Cat-M1. Also called Long Term Evolution for Machines (LTE-M), Cat-M, or eMTC, this network is another 3GPP-defined LPWAN standard network. Similar to NB-IoT, Cat-M1 extends the current LTE standard; however, it can transit much higher data rates than NB-IoT can. T-Mobile recently expanded its IoT networks to include a Cat-M1 network. Cat-M1 networks are superior to NB-IoT in terms of bandwidth and data rates.

Like NB-IoT, CATM1 is an ideal IoT coverage solution for many use cases and vertical industries. These include:

  • Healthcare
  • Transportation
  • Utilities
  • Construction and Real Estate
  • Insurance
  • Manufacturing & Industrial
  • Smart Cities
  • Smart Agriculture


Older LPWAN networks include LoRa and Sigfox. LoRa (also known as Long Range or LoRaWAN) is a proprietary low-power wide-area (LPWAN) network of Semtech. Its modulation technique doesn’t fall under the 3GPP standard. LoRa instead uses an unlicensed frequency and supports a smaller bandwidth than Cat-M1 or NB-IoT networks but is slightly larger than Sigfox.

Because it’s a private, proprietary network, there are some disadvantages. To transmit and receive, you would have to buy additional equipment (added costs). The network itself is riskier because there’s no support to keep your IoT applications running if the company were to go under. 

Who is LoRa For?

Like IoT itself, IoT connectivity is constantly evolving as well. Because LoRa is an older network with a much smaller bandwidth, it’s best for applications that are:

  1. Non-Critical
  2. Mainly Uplink-Oriented
  3. Generate Low Traffic
  4. Battery-Powered
  5. Require a Low-Cost Sensor


Similar to LoRa, Sigfox is a proprietary, unlicensed network owned by a company called Sigfox. One major disadvantage to a proprietary network such as Sigfox is that they have to be built out over time, unlike carriers (like T-Mobile and AT&T) who already have vast network coverage to support LPWAN networks.

Therefore, Sigfox does have some limitations to whether or not you can use it based on your location. Sigfox networks won’t have the large nationwide, and global coverage footprints like other networks will have. This means you also don’t have the instant scalability like you would if using a T-Mobile network. 

Who is Sigfox For?

Since Sigfox’s capacity going from the base station back to the endpoint is constrained, Sigfox is best used in only certain use cases. To use bidirectional command-and-control functions, you need a higher network density. Because of this, IoT applications that only send small and infrequent bursts of data, like alarms and meters, are best suited for a Sigfox network.

Benefits of Using a T-Mobile Network

There are pros and cons to operating on a 3GPP licensed or unlicensed IoT network. If you’re still on the fence, here’s a look at three major benefits to using a T-Mobile NB-IoT or CATM1 network.

1. End-to-End IoT Security

T-Mobile works with its customers and partners to build security into IoT solutions from end to end. From physical device security and software/firmware updates to transport encryption and authentication/authorization requirements, T-Mobile takes a holistic approach to IoT security.

2. Reliable Nationwide & Global Coverage

T-Mobile’s known for its wide-spanning nationwide coverage, which doesn’t change with its NB-IoT and CATM1 networks. NB-IoT and CATM1 networks were designed to provide reliable and secure connectivity for IoT devices nationwide and in 125+ countries and destinations around the globe. 

3. Instant Scalability

Because of T-Mobile’s broad network footprint, you’re set up for instant scalability and rapid deployment regardless of your location or number of IoT devices. Furthermore, if you start with a smaller number of “things” and end up quickly growing, you can easily expand your IoT connectivity without any hassle.

SIMON IoT - Head of Content, SIMON IoT

IoT connectivity companies often make pricing and onboarding difficult. At SIMON IoT, we shatter expectations with transparent pricing for data and SIM cards. There is no guess work
IoT connectivity companies often make pricing and onboarding difficult. At SIMON IoT, we shatter expectations with transparent pricing for data and SIM cards. There is no guess work