Cellular IoT Explained: The Pros and Cons

Cellular technologies provide engineers with multiple options for IoT deployment – but careful considerations must be made.

Cellular IoT has grown in popularity recently as engineers have looked to build flexibility and reliability into their digital deployments.

These days, multiple types of sensors, actuators and other devices can be connected to the internet using the same infrastructure as mobile phones. And as cellular generations have progressed – from 3G to 4G, and now 5G – cellular IoT has become a significant rival to other architectures such as Wi-Fi or wired Ethernet.

However, while cellular IoT can deliver significant advantages in specific areas, such as coverage, flexibility and cost, there are better fits for some applications.

Indeed, engineers need to carefully weigh up several considerations before deciding on the most suitable connectivity standard to adopt. This decision can have a critical influence on the reliability and efficiency of any IoT deployment.

So, let us look at how cellular IoT stacks up against competing wireless architectures such as Wi-Fi by highlighting some of the most important advantages and disadvantages, helping engineers select the right approach for their connectivity needs.

Where cellular IoT excels

Security: Cellular provides exceptionally high privacy and security standards, taking advantage of established architecture provided by existing carriers. Cellular IoT separates devices from each other, maximising data security. Devices are installed with an embedded SIM card for authentication, giving each a unique ID. Meanwhile, devices linked to a Wi-Fi network share the connection with other physical objects – and a security threat to one device can be a risk to all.

Low power: Cellular architectures such as NB-IoT and LTE-M are Low Power Wide Area Networks (LPWAN) and, as such, have been specifically designed to offer low power consumption, particularly for battery and solar-powered devices. Cellular modules can consume as little as ~8mA of power during idle periods. Since data throughput is often limited – with more intelligent wake/sleep modes often built-in – power requirements are kept at an absolute minimum. It is not uncommon for cellular IoT devices to have a battery life of ten years in the field.

Coverage: Cellular networks are pervasive, reliable and well-established – with 4G network coverage doubling to 88 per cent of the world's population between 2015 and 2021. These extensive networks mean cellular IoT's range is not as limited as Wi-Fi, representing a viable proposition in many remote locations. 4G LTE-M and NB-IoT have also exhibited strong indoor penetration through infrastructure such as concrete walls and deep underground. This presents an option for utility providers looking to monitor assets such as smart meters and pipe networks.

Remote monitoring: With the right IoT platform in place, it is possible to interrogate cellular devices remotely – turning them off or on or fixing problems without being on location. The same software can also be used to monitor the performance of devices, fine-tuning specific metrics to improve reliability and efficiency. This capability can provide significant savings over time, with maintenance technicians able to manage devices individually rather than collectively, minimising downtime and cutting costs.

Scalability: Cellular connectivity can be scaled quickly and easily, with no requirement to acquire new equipment, such as routers, as the network is expanded. This flexibility makes cellular IoT ideal for massive IoT deployments, which will be supported in the future by the more widespread rollout of 5G. Expansion of cellular networks is also supported by the ease of configuration – with devices connecting to cell towers pretty much out of the box, with little requirement for specialist – and therefore expensive - technical expertise. Therefore, ease of installation and operation is a significant selling point.

Where Wi-Fi comes into its own

As we said at the start, though, there is no one-size-fits-all approach to IoT deployment. While cellular IoT has acknowledged advantages in terms of security, power usage, coverage, remote monitoring and scalability, there are times when alternative wireless approaches such as Wi-Fi provide a better option. Here are a couple of the primary advantages of Wi-Fi so that engineers can achieve optimal connectivity, whatever the application.

Speed and throughput: When it comes to limited spaces, Wi-Fi is the go-to solution when higher speed and data transmission is required. Wi-Fi generally takes advantage of higher frequencies – usually between around 2.4 GHz and 5 GHz. So wireless connectivity through Wi-Fi would typically be selected for IoT deployment in a defined space – like a single manufacturing facility, with high data throughput. But 5G could change that, putting cellular networks on an even footing with Wi-Fi in this regard.

Cost: Under some circumstances, cost advantages can be realised through Wi-Fi deployment, particularly where large amounts of information must be transferred daily. Typically speaking, Wi-Fi has no cost limitations on the amount of data sent for processing. Wi-Fi would generally be seen as less expensive than cellular when measured on a per-device basis. Still, the cost of maintaining and managing the Wi-Fi network – including staffing and other support costs – needs to be taken into account.

Looking to the future

To conclude, engineers have a multitude of options when deploying IoT. Several considerations, from application requirements, network coverage, power needs, and project costs, must be uppermost in mind. Other factors such as the location of end devices – offsite, distributed or mobile – come into play.

Generally speaking, cellular IoT presents a sensible option where devices or physical objects need to be deployed over remote or dispersed areas where Wi-Fi is limited. It can provide excellent coverage, superior security, ease of installation and operation, along with ‘fit and forget’ low power requirements for reduced maintenance costs, delivering savings over time.

No wonder that cellular IoT has emerged as a tried and trusted technology in recent years. And with 5G connecting more devices with faster data speeds and lower latency, it would seem to be a technology that is here to stay.

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