IoT connections outlook

NB-IoT and Cat-M technologies will account for close to 45 percent of cellular IoT connections in 2024.

Report  | 

Key findings

  • Cellular IoT connections are predicted to increase from 1 billion in 2018 to 4.1 billion in 2024.
  • By the end of 2024, nearly 35 percent of Cellular IoT connections will be Broadband IoT, with 4G connecting the majority.
  • The first modules supporting Critical IoT use cases are expected to be deployed in 2020.

To date, 2G and 3G connectivity has enabled many cellular IoT applications. In recent years, support for large volumes of devices has been enabled by the Massive IoT technologies NB-IoT and Cat-M1 deployed on top of LTE networks.

Cellular IoT use cases will have differing connectivity requirements. A heat sensor in a basement will need deep coverage and have low throughput, whereas a connected robot on a production line may require ultra-low latency, high reliability and high throughput. Cellular IoT use cases can be divided into four segments based on their connectivity requirements.

Massive IoT

This segment primarily includes wide-area use cases, connecting massive numbers of low-complexity, low-cost devices with long battery life and relatively low throughput. Support for these is already being provided in today’s LTE networks with NB-IoT and Cat-M. These technologies complement each other and there is an emerging trend towards service providers deploying one common network supporting both technologies. Cat-M is suited to use cases that require relatively higher throughput, lower latency and voice support, whereas NB-IoT is suited to use cases with very low throughput that are tolerant of delay but require extended coverage.

Cellular IoT connections by segment and technology (billion)

Verticals using Massive IoT include utilities with smart metering, healthcare in the form of medical wearables and transport with tracking sensors. At the end of 2024, NB-IoT and Cat-M are expected to account for close to 45 percent of all cellular IoT connections. In the future, NB-IoT and Cat-M will be able to fully co-exist in spectrum bands with 5G NR.

IoT connections (billion)
Cellular IoT use case segments

Broadband IoT

This segment mainly includes wide-area use cases that require higher throughput, lower latency and larger data volumes than Massive IoT technologies can support. LTE networks are well prepared to support use cases in this segment, as the technology can provide peak data rates in the multi-Gbps range and radio interface latency as low as 10ms. LTE is already connecting millions of modern cars, and there are LTE-capable smart watches.

By the end of 2024, nearly 35 percent of cellular IoT connections will be Broadband IoT, with 4G connecting the majority. When moving to 5G, with higher speed, lower latency and other capabilities, even more advanced use cases can be supported. Throughputs in the tens of Gbps and latency as low as 5ms will be possible.

Critical IoT

This segment includes both wide-area and local-area use cases that have requirements for extremely low latency and ultra-high reliability. 5G NR networks with support for Ultra-Reliable Low-Latency Communication (URLLC) as defined in 3GPP will be needed and will enable complex use cases such as interactive transport systems in the automotive industry, smart grids with real-time control and distribution of renewable energy in the utilities industry, and real-time control of manufacturing robots in the manufacturing industry.

The first modules supporting Critical IoT use cases are expected to be deployed in 2020. Only a small fraction of total cellular IoT connections will be Critical IoT in 2024.

Industrial automation IoT

This segment consists of very specific use cases, with the most demanding requirements coming from the manufacturing and industrial sites. Time-sensitive networks, industrial protocols running over ethernet, and very precise positioning will be needed.

Functionality to support this segment is currently being defined in 3GPP, influenced by Industry 4.0 initiatives and industry bodies such as 5G-ACIA. It will be a 5G-specific segment valid for local area use cases and private network deployments. As standardization is still ongoing, no forecast is included for this segment.


Today, the majority of cellular IoT devices are connected via 2G and 3G technologies (GPRS, EDGE and HSPA). The number of legacy connections is expected to increase slightly until 2022, and then remain stable throughout the rest of the forecast period.

1 Cat-M includes both Cat-M1 and Cat-M2. Only Cat-M1 is being supported today

2 These figures are also included in the figures for wide-area IoT

3 Co-operative Intelligent Transport System