Cellular IoT Explained: A Quickfire Guide to Mobile Connectivity

The emergence of the Internet of Things has seen billions of connections of physical devices seamlessly exchanging data - driving innovation in smart homes and factories worldwide.

These devices often speak to each other via wireless communication protocols, depending on geographic location, budget and power consumption needs.

Typically speaking, Wi-Fi is one of the most popular IoT communication protocols, especially for Local Area Networks, which require fast data transfer across a defined location. Wi-Fi is cost-effective and easy to deploy – so there is little surprise that it plays a central role in most IoT environments.

But in some circumstances, Wi-Fi has its drawbacks. It is, for example, limited in its range – although it can be augmented through extenders and mesh networking - and it is more vulnerable to security threats. Wi-Fi networks also need a network router and have limited coverage. So, for the engineer looking to establish an IoT connection, there are necessary trade-offs to consider.

If Wi-Fi is not the answer, what else might be the solution? Step forward cellular IoT – a technology that makes it possible to connect physical objects to the Internet using the same cellular network deployed by the smartphone in your pocket. At a simple level, cellular IoT connects IoT devices using established mobile networks, including 3G, 4G/LTE or 5G – eliminating the need to invest and deploy a separate dedicated network infrastructure.

The benefits offered by cellular IoT mean that it has become a big business. According to recent research, the global cellular IoT market was valued at almost $4 billion in 2021 and is expected to grow to $15.4 billion by 2027. This rapid expansion is being built on increasing cellular IoT deployment in areas such as city infrastructure and building automation, agricultural automation and environmental monitoring.

Cellular IoT brings a distinct operational advantage in each case over other communication protocols, such as Wi-Fi, thanks to its unique technical characteristics. So, let us take a deeper dive into the A-to-Z of cellular IoT, understanding how it works and why it could be used to support your future IoT deployments.

What infrastructure would a typical cellular IoT network require?

Cellular IoT technology enables physical objects or devices to connect to the cellular network, facilitating data transmission. The cellular network comprises core and radio access networks, enabling communication between IoT devices and the core network. Base stations provide wireless connectivity to IoT devices, transmitting and receiving signals to and from physical objects. A gateway serves as a bridge between the IoT devices and the core network, collecting data from the devices and sending it to the core network for processing and analysis. Meanwhile, a cloud platform is used to provide data storage, processing, and analysis infrastructure. Application software also plays a crucial role in analysing and visualising the data gathered by IoT devices - enabling users to remotely monitor and control IoT devices and empowering them to make informed decisions based on the collected data.

What are the primary options for cellular IoT connectivity?

Cellular technologies have evolved over time. Initially, second- and third-generation cellular networks (which are now being phased out in many parts of the world) progressed from architectures such as GSM and GPRS to Universal Mobile Telecommunications Systems and High Downlink/Uplink Speed Packet Access, providing a bedrock for IoT applications. Then, 4G came along, offering extensive coverage in most parts of the world and download rates of 150 Mbps. With 5G rates, up to 1 Gbps are possible already, with 10 Gbps likely in the future and sub-one millisecond latency. Depending on the end use, 3G, 4G and 5G offer acceptable data rates for IoT applications. So, a range of options exist.

How are newer technologies being optimised for cellular IoT?

While 5G represents the gold standard of cellular connectivity, its high capacity and low latency performance often exceed the requirements of IoT devices which require low amounts of data and have power constraints. Therefore, other cellular architectures, such as LTE-M and Narrowband-IoT (NBIoT), have been refined for IoT applications. Both technologies take advantage of Low Power Wide Area Networks (LPWAN) and are built on the LTE standard – a worldwide standard for 4G transmission - providing excellent global network coverage. LTE-M and NBIoT are designed explicitly for low-cost IoT applications that require low data rates and long battery lives and often operate in geographically remote locations. Increasingly, LTE-M and NBIoT provide the apparent solution for end-users who want to move on from soon-to-be phased-out 2G and 3G connectivity, providing end users with a significant operational advantage in device battery life and coverage.

What is the scope of LTE-M and NBIoT deployment to date?

LTE-M and NBIoT are sometimes called mobile IoT, reflecting the flexible scope of end-user applications. Both technologies are now well established with global coverage, enabling application service providers to deploy and operate their solutions worldwide. According to the GSM Association, as of mid-2022, more than 80 NB-IoT networks were deployed commercially in over 45 markets and 30 LTE-M Networks in over 25 markets. Use cases have increased in connected or smart homes, agriculture, robotics, smart industry, smart cities and energy, and utilities.

What specific applications have been established across key verticals?

LPWAN technologies are seen as an efficient and cost-effective means of connecting multiple IoT devices – particularly in remote locations where poor coverage has previously been a problem. In connected cities, applications have included intelligent street lighting, road traffic monitoring and infrastructure sensors, while connected living has seen asset tracking and location security deployment. Industrial applications include warehouse monitoring, safety, and security, while agriculture has used the new connectivity levels for crop and animal motoring. Finally, utility providers are increasingly fitting sensors using LPWAN connectivity to monitor infrastructure at water treatment plants or pipe networks.

What is next for cellular IoT?

LTE-M and NB-IoT look set to improve coverage and capacity in support of massive IoT deployments, with more devices connected to a single cell, enhancing indoor coverage, and expanding coverage in remote areas. 5G networks will work in combination with LTE-M and NB-IoT to support a broader range of IoT use cases, with better integration enabling seamless handover between networks. Power efficiency is another area where progress will be made through features such as advanced sleep modes. And finally, while LTE-M and NB-IoT are designed for low-bandwidth, there will be a rising demand for higher data rates as IoT applications become more sophisticated, while maintaining low-power consumption.

Articles in this series:

• Cellular IoT Explained: A Quickfire Guide to Mobile Connectivity
• Cellular IoT Explained: The Pros and Cons
• Cellular IoT Explained: Implementing Cellular Connectivity
• Cellular IoT Explained: Five Ways Cellular IoT is Transforming Our Lives