Do cellular IoT communications fit your IoT strategy's needs?

Pros and cons of cellular IoT connectivity

"The pros of cellular are obviously its footprint for transportation and vertical markets with geographic challenges like the electric grid," said Christian Renaud, research vice president for IoT at 451 Research. "And with LTE, and eventually 5G, we're going to gain speed and lower latency, which will enable new applications."

Many IoT applications are part of a control loop, with strict latency requirements (less than 50 or even less than 10 milliseconds), which Renaud called a challenge for 2G and 3G networks, adding that "4G got closer, and 5G nails it by deploying many more cells and using frequency better."

Carrie MacGillivray

The downsides of cellular IoT connectivity? Cost and susceptibility to interference. "Say I have a device that sends a level reading of a fuel tank once a day so you know whether to dispatch a truck there or not; I'm not going to want to pay $30, $50, $100 per month for that connection," Renaud said. "And susceptibility to interference is also a key concern for mission-critical applications like grid control and precision manufacturing."

Today, cellular use is widespread in transportation and retail, which isn't overly surprising. But it's used less frequently in manufacturing and energy, which, according to Renaud, is a bit of a surprise. "Energy, oil and gas operations are often outside of cellular range -- in Siberia, the Arctic Circle or the Gulf of Mexico -- so there's no coverage, and the electric grid can sometimes be in the same boat with its transmission lines, going for hundreds or thousands of miles through rural areas with limited coverage," he said.

Choosing a cellular connectivity provider for IoT applications

It's a good idea to consider shaping your carrier plan and selection to your specific workload or application, Renaud said. "If you're, say, a Redbox kiosk with a handful of authorization requests or credit card charges per hour, you can estimate how many connections you'll have, the data volume and shop around for the best price."

Then again, Renaud advised, if your operation involves video surveillance cameras, then you might want to prioritize plans and carriers with as close to unlimited data as you can get or consider doing local video analytics on the camera itself and uploading metadata for a fraction of the cost.

Christian Renaud

At this stage, he added, multiple cellular routing vendors have platforms that are multi-SIM or multicarrier, so companies can negotiate contracts with multiple network operators and arbitrage between different plans based on how close they are getting to data limits and if they are seeing performance issues on a particular carrier.

So what if you run a big agricultural production or ranch in a remote location and want to tap into the internet of thing? Is cellular IoT connectivity a viable option? "If it's a big agricultural site, then the chances are that cellular density isn't there, but that they'll have a good quantity of soil sensors or grazing land sensors," Renaud said. "In quantities that high, it wouldn't be cost-effective to pay a cellular subscription using current pricing models. This is where low-power wide-area networking has an edge."

For infrequent low-traffic applications like agriculture, a single tower that covers hundreds of miles of agricultural land has an advantage, Renaud elaborated. "Also, sensors have finite battery lives that are impacted by the power of broadcasting, the frequency of connections, etc. Batteries that can last years between replacements requiring a truck roll are more cost-effective than traditional cellular batteries that require replacement within days or weeks at normal transmission rates."