Get Connected Blog | Nordic Semiconductor

Building high-density IoT networks with cellular IoT and DECT NR+

Written by Martin Lesund | February 28, 2024

In the future, the IoT will become ubiquitous with billions or even trillions of ‘things’ connected to the Cloud. These things aren’t just the PCs, servers, smart TVs, and smartphones traditionally associated with the Internet, they’re also small sensors and actuators—typically without a user interface—that monitor what’s going on in their environment and react accordingly. In metropolitan areas that could well mean millions of connected devices per square kilometer.

Engineers are already coming up with solutions to solve the engineering problems the proliferation of connected devices will bring. And they’ve coined a phrase to describe these future high-density networks: “massive IoT”.

The characteristics of massive IoT

Networking and telecommunications company Ericsson describes massive IoT applications as generally being less latency sensitive and not required to handle large amounts of data per device; rather the applications comprise many low-cost, energy-efficient devices covering large areas with a high volume of connections. The growing demand for massive IoT is driven by the rising popularity of use cases that align with these parameters, for example wearables, smart buildings, smart meters, asset tracking, industrial automation, and smart agriculture.

Just a few years ago, connecting all these small things to the IoT was difficult and relied on expensive and complex gateways because each device typically used a different, non-interoperable technology. However, today we have an elegant solution that does away with gateways and brings interoperability; called cellular IoT, if comprises LTE for Machine-Type Communications (LTE-M) and Narrowband Internet of Things (NB-IoT) technology

The power of cellular connectivity 

Cellular IoT LPWANs are growing quickly due to their efficient, cost-effective, and long-range wireless connections between WLANs and the Cloud. Because cellular IoT uses regulated spectrum, access to the network is tightly controlled - with each device requiring a Subscriber Identity Module (SIM). While cellular IoT attracts data charges, it ensures widespread, robust, interference-free, and highly secure connectivity, suitable for massive IoT.

Analyst Statista says that LTE-M and NB-IoT together make up 47 percent of the current LPWAN market, making them the leading choices for secure and reliable long-range connectivity.

LTE-M is best suited to applications requiring relatively high uplink and downlink speeds. It is also ideal for mobile applications, such as asset tracking. In contrast, NB-IoT focuses on static applications with better indoor and underground coverage, the trade-off being lower throughput. 

Updated for 5G

While NB-IoT and LTE-M were originally created as part of the 4G LTE standard, they have now become part of the latest 5G standard (defined by the ITU Radiocommunication Sector (ITU-R)) ensuring ongoing adaptation as the network matures.

This evolution is crucial, as the next phase of massive IoT development will rely on these 5G networks. Specifically, engineers are focusing on ‘massive machine type communication’ (mMTC), which will use low power wireless connectivity for widespread machine-to-machine (M2M) applications. The technology will be designed to support up to one million devices per kilometer.

DECT NR+: The non-cellular alternative for massive IoT

NB-IoT and LTE-M are evolving to meet the needs of mMTC, but they won’t be alone; DECT NR+ (“NR+”) also meets all the technical requirements for mMTC. NR+ is defined as a 5G technology, but while it shares some technology with cellular protocols it is not itself a cellular protocol.

NR+ operates in the 1.9 GHz global, license-free spectrum, which lowers operational costs as there are no data charges. Instead of having to use licensed networks, engineers can build high-density private mesh networks without the need for SIMs. These networks can cover hundreds of meters indoors or several kilometers outdoors, accommodating up to four billion unique radio devices in a single network. They can also be customized to support high data rates (up to several gigabits per second) or low power consumption (below 10 microamps on average).

Low cost, large scale connectivity

NR+ ensures reliability and low latency, making it suitable for important applications like key infrastructure. It is also reliable and robust because it uses self-healing mesh networking techniques, meaning that if one point fails, data can still be transmitted and received using the remaining nodes. NR+ also promises latencies similar to those of wired networks. For instance, Nordic’s first nRF91 Series-based NR+ solution offers one-millisecond latency between devices and a throughput of three megabits per second. This performance is applicable to densities of up to one million devices per square kilometer - making NR+ well suited to massive IoT applications. 

Nordic introduces solutions for massive IoT

The Nordic product lineup has expanded to add NR+ solutions to its existing cellular IoT products. Joining the nRF9160 SiP are the nRF9161, nRF9151 and nRF9131 LTE-M/NB-IoT and NR+ solutions. These new products not only broaden the scope of cellular IoT but also introduce NR+ support and capabilities to the technology for the first time.

By providing support for a future massive IoT, cellular IoT and NR+ technology will not only boost productivity, enhance leisure activities, and improve education, but will also us address global challenges like climate change, sustainable living, resource conservation, and improved health - creating a better world for all.