The Internet of Things (IoT) already feels omnipresent, but projections indicate its growth is only expected to continue. We have all heard the forecasts of 50 billion connected devices in just a few years. It’s difficult to fathom the sheer volume, but it also raises a few questions. Perhaps chief among them from a functional standpoint is the question of what networks will those devices connect to?
For industrial applications in particular, there are a handful of strong options fighting for space in the marketplace of IoT-dedicated networks. These low-power wide-area networks (LPWA) – so called “data-dribblers” that operate for years at a time while transmitting small pieces of information – include unlicensed spectrum options like Sigfox, LoRa, and Ingenu; as well as licensed spectrum options based on cellular standards like NB-IoT and LTE-M.
The unlicensed spectrum options are more than viable. Sigfox is extremely low power and low throughput over an open standard, but it has the drawback of requiring a Sigfox network. LoRa and LoRaWAN, while claiming to be open standard, require the use of a Semtech chip – and use a little more power. However, they also offer enough bandwidth even for bi-directional communication. On the licensed side, NB-IoT is very low power and offers good throughput, but is primarily focused in Europe and doesn’t have a strong foothold stateside.
These days most of the North American buzz surrounds the licensed spectrum of LTE-M cellular networks. Verizon recently launched the first U.S.-wide LTE-M network covering 2.4 million square miles and AT&T is not far behind with its LTE-M offering. These launches were expected: LTE-M was set to be the IoT-dedicated cellular standard in the United States as NB-IoT was in Europe. But now LTE-M is drawing interest worldwide to the point of some raising the question of whether NB-IoT will maintain its international position.
The 3rd Generation Partnership Project (3GPP) set the standards that help differentiate these LTE-M networks that large cellular carriers are rolling out. While it’s not as power-efficient as other technologies, LTE-M – which I like to describe in layman’s terms as the little brother of the big LTE you know from your smartphone – provides the most bandwidth of the bunch, along with the best inherit security.
Sounds great, right? There’s no twist – it really is! But like any network you must consider the types of applications running on it, the devices connecting to it, and the other options in the IoT-dedicated network marketplace.
LTE-M Applications
If you think of IoT applications, you might think of industrial controls, security systems, smart cities, or precision agriculture. Just considering the diverse requirements of that handful of systems it’s clear that not every IoT solution has the same network needs. Some may need to ping a sensor at a given interval, others need constant monitoring. Some may need relatively high throughput, while others can manage with a much lower bandwidth.
LTE-M is great for those scenarios that require a low-power network but without much latency and a greater throughput than similar options. In fact, LTE-M networks go beyond the utility required for applications built around automated sensor readings like in transportation or cold chain; they can even be used for voice applications like you might find in residential security systems.
Although they still operate on a low-power network, applications that require LTE-M will typically be more robust and require higher data rates from their network.
Original Equipment Manufacturer (OEM) Considerations for LTE-M
In theory, LTE-M could be scary for OEMs. These networks have been ramping up for some time, but it is a new technology coming to market and OEMs can no longer be in the preparation stage. Luckily, integrating embedded cellular connectivity should be less of a challenge in practice than it may seem.
Embedded cellular gateways are available to make building devices for LTE-M networks simple while eliminating costly time and capital expenses on developing their own cellular connectivity capabilities. Moreover, a pre-certified connectivity device eliminates the carrier certification process that can grind development and deployment to a halt.
Not only do embedded cellular options provide the fastest path to LTE-M connectivity, they free OEMs to focus on building their best possible device and getting it to market immediately.
Security Considerations for Devices on LTE-M
The biggest security concern for LTE-M devices will be not due to the network, but user error with their connected devices. While the network’s security is strong, devices are only as secure as they are allowed to be. Factory setting passwords or outdated firmware are always liable to create exploitable vulnerabilities. Is it cheating to say that the main consideration for guaranteeing security on LTE-M networks is to follow best practices for device safety and system hardening? Maybe so, but it always bears repeating.
The IoT-dedicated LPWA Marketplace
There is no blanket solution for the best wireless IoT network. LoRa, Ingenu, and Sigfox have their merits, as does LTE-M. What’s clear, however, with Verizon’s LTE-M network live and AT&T’s not far behind, is that LTE-M will have the most powerful players behind it. LTE-M is here to stay, and with its somewhat surprising support in Europe it appears that it will be a global phenomenon.
Joel Young is CTO of M2M and IoT communications and technology company Digi International and Board Chairman on the IoT M2M Council (IMC).
Filed Under: IoT • IIoT • Internet of things • Industry 4.0, Infrastructure