Connectivity enables the wireless communication that makes up the heart of the Internet of Things (IoT)—IoT devices communicate with gateways and gateways communicate with the cloud, often via cellular data connections. But there are so many technologies (and acronyms!) in relation to IoT connectivity that it’s easy to get lost in all the options. As more companies begin to investigate the possibility of deploying IoT projects, however, it’s increasingly important to understand the various connectivity offerings so you can match your company’s specific needs to the right solution.
In general, IoT connectivity solutions fall into one of three categories: cellular, Local and Personal Area Networks (LAN/PAN), and Low Power Wide Area Networks (LPWAN). In this article, we’ll focus on comparing two connectivity standards vying for dominance within the cellular category: LTE-M vs. NB-IoT (Narrowband IoT), and put them in context with regard to the most important requirements for IoT devices.
LTE-M Vs. NB-IoT: What’s the difference?
To provide some background, both LTE-M and NB-IoT were created by the cellular industry in response to the rise of LPWAN technologies, which were specifically developed for IoT use cases. These new cellular standards were designed to support device communication via carrier networks in a way that’s less expensive and more power-efficient than traditional telecom standards (used for cell phone communication).
In general, any type of cellular connectivity is more costly than LAN, PAN or LPWAN technologies—the chipsets are expensive, they require expensive testing and certification, and they are relatively power-hungry. However, there are pros and cons to using any type of technology. The cellular advantage is in the area of coverage—it operates nearly everywhere, except, of course, in remote areas where cell coverage is typically poor or limited. In addition, cellular-based IoT devices communicate on licensed spectrum, which means performance is generally good.Any type of cellular connectivity is more costly than LAN, PAN or LPWAN technologies—the chipsets are expensive, they require expensive testing and certification, and they are relatively power-hungry. Click To Tweet
Before LTE-M, there were several categories of higher speed LTE—the standard for wireless broadband communication for mobile devices. Using LTE 4G for IoT devices was not very power efficient, because the chips used to talk to cellular had to use excessive amounts of battery power to identify relevant messages. As a result, LTE was deemed an inefficient connectivity method for IoT devices, and alternatives (like the Sigfox network) began to emerge.
Seeing the need for IoT-only network technology, 3GPP, the standards organization that develops protocols for mobile communication, developed LTE-M. Also referred to as LTE Cat M1, LTE-M is a stripped-down version of LTE. It uses the same spectrum and base stations, and works everywhere that LTE works. The major difference between LTE and LTE-M is that it’s simpler, which means battery-powered IoT devices can send and receive data online via cell phone carrier networks in a more power-efficient way. An iPhone battery lasts a day, but a cell modem-connected water meter battery could last years—a significant improvement with regard to cellular IoT devices. However, LTE-M requires more battery power than NB-IoT.
One of the reasons LTE-M is a more costly connectivity option is because several large players have patents on the underlying technologies; LTE-M users pay royalties to these companies for the use of their intellectual property.
|The bottom line: LTE-M is a great option for IoT connectivity if you’re willing to pay the price, and if your use case requires low power. Another bonus: LTE-M networks are already in place in the U.S., which means you can start taking advantage of this option today, which, as you’ll see, is not quite the case with NB-IoT. LTE-M can be used for everything from water meters to agricultural monitors and beyond; it serves a very broad set of use cases.|
Some stakeholder groups felt that LTE was way too complicated for IoT and wanted to create something new. The cellular protocol they envisioned, called NB-IoT, was developed specifically for device communication using simpler, cheaper chips that require less power. It also makes use of the small “orphan” pieces of the radio frequency spectrum.
Although NB-IoT is a fairly attractive connectivity option, it is currently more prevalent in Europe and Asia. It is still not widely available in the U.S., although some carriers (like Dish Network and T-Mobile) have coverage in some places. Despite that fact, NB-IoT has promise. There are loads of 200-kHz GSM spectrum assets that aren’t being used, and proponents want to see NB-IoT deployed on it. NB-IoT also doesn’t have the intellectual property pedigree that LTE does, which means users pay less in royalties.
|The bottom line: NB-IoT is somewhat less costly than LTE-M and uses less battery power, but there’s not enough coverage everywhere to reliably deploy an NB-IoT solution yet. However, U.S. coverage is likely to expand in the future. NB-IoT is best for things like water meters, electric meters, and GPS trackers.|
A Cellular Alternative
NB-IoT and LTE-M aren’t your only options for connectivity. If you’re interested in learning more about the Iota network and our easy-to-deploy IoT solutions for your business, get in touch. We’ve helped numerous companies streamline their operations, cut costs, and increase their sustainability using the IoT, and we can do the same for you.