Massive sensing: How billions of small devices could become 5G’s next very big thing.

The 3^rd Generation Partnership Project (3GPP), a consortium of telecommunications standards organizations, is working on standards for a category of 5G services called Massive Machine-Type Communications (mMTC) that, theoretically, will be capable of supporting billions of sensors in a smart city or other geographic area spanning kilometers. 

We say theoretically because mMTC 5G services are still largely on the drawing board. But the specifications have already been codified in 3GPP’s Releases 16 and 17. These 3GPP standards are intended to ensure that various companies’ hardware and supporting software can seamlessly interoperate in the new applications of 5G technology. And this evolving standard lays the foundation for mMTC-capable devices to be manufactured for massive sensing—and eventually make them more widely available and affordable for businesses to deploy at scale.

mMTC is designed for low power consumption, long battery life, low-cost hardware, and very high density—in the range of 1 million sensors per square kilometer. Those characteristics, which are supported by the 3GPP specifications, are essential for the concentrated, highly connected environments that are envisioned in smart homes, factories, and cities. 

And because mMTC is a cellular service, it provides wireless connectivity across wide geographic areas that are beyond the reach of local Wi-Fi networks.

Equally important is that mMTC will coexist with earlier low power, wide area (LPWA) cellular services that also support IoT. These technologies include LTE Machine Type (LTE-M) and Narrowband IoT (NB-IoT), both of which have also been standardized by 3GPP. They are used for connectivity to electric and gas meters, smoke detectors, and other devices. 

Because these and other technologies—including Wi-Fi and near-field communications—are already used for IoT connectivity, 5G won’t be an entirely new “greenfield” wireless opportunity in such scenarios. mMTC may be one of several wireless solutions in enterprise environments, underscoring the importance of the 3GPP standards work that is underway.

But mMTC will play a vital role in taking network sensing to a new level in terms of device density within a geographic area, battery life, and other factors. 

“We can see from the success of 4G that there’s demand for this,” says Satapathy. “Mobile sensor applications and use cases are growing rapidly, and businesses need to plan for that.”

Sensors typically create small, infrequent bursts of data. But those little bits of information can add up quickly when there are millions or billions of devices producing them. 

The expectation is that massive sensing will spawn tremendous amounts of data that can be processed by AI and ML algorithms. The output of all that high-scale data processing can be used to analyze the operations of sensor-enabled environments and optimize their performance. “I think there’s tremendous potential for the insights you can get from applying AI and ML to this,” says Satapathy. 

For example, the terabytes of “big data” produced by sensors and other devices in a factory might be used for real-time error detection and predictive maintenance.

mMTC is one of three categories of 5G services defined by 3GPP, along with Enhanced Mobile Broadband (eMBB) and Ultra-Reliable, Low-Latency Communications (URLLC). Communication service providers will be able to offer this triad of services through a technique called network slicing, which uses 5G’s software-defined network architecture to establish an end-to-end logical connection for each service.

Yet, because massive sensing is still in the early stages of development, some of the underlying pieces are still being put into place. As mentioned above, sensors compliant with the latest 3GPP standards are not yet widely available or affordable to deploy at a massive scale. 

As such, the telecommunications industry is still on the development curve—and the learning curve. “The commercial readiness of a lot of the industrial 5G capabilities is still two, three, or four years away,” says Leonard Lee, managing director and founder of neXt Curve, a research advisory firm. 

During this nascent phase, implementation of massive sensing can be complex and difficult, Lee says. But it’s not too soon to start planning for it. 

“The potential is exciting, but it will require thoughtful exploration,” Lee says. “Once you have sufficient network deployment of mMTC features and network-ready devices, all of a sudden you have new categories of applications that become possible.” 

While it may be hard to know with certainty what new categories of applications might emerge, Lee points to water metering and conservation, suburban and urban agriculture, and landscape management as among the possibilities. 

At T-Mobile, research is underway to develop best-in-class mMTC services for business customers that want to deploy massive sensing. “We have done the fundamental technical work in these areas,” says Herkole Sava, Director, Advanced & Emerging Technologies, with T-Mobile. “We already have the foundation and a good understanding of where the technology is going and where it can be applied.”

As is often the case with leading-edge technologies, the timing of adoption of mMTC services is hard to predict. But T-Mobile’s 5G network will be ready as business customers begin to take advantage of massive sensing in pursuit of innovation, efficiency, and automation.