IoT connectivity is a term referring to the connection between all the devices in the IoT system, including sensors, network routers, gateways, applications, and even platforms/systems. In practice, however, it usually refers to the different types of network solutions we can use in an IoT system from Wi-Fi to cellular connectivity to newer technologies like NPWAN and NB-IoT.
We can differentiate these IoT connectivity options based on three main factors: bandwidth capacity (speed), coverage range, and power consumption. Different IoT systems might need different connectivity requirements based on the needs and objectives of the project.
IoT connectivity can make or break the whole IoT system. Without connectivity, the IoT system simply won’t perform, and choosing the wrong connectivity solution can hinder the IoT project’s performance, cost-efficiency, and scalability, among other things. There are, in fact, many failures in IoT that are attributed to how the connectivity solution can’t keep up with the rapidly growing data transfer in a growing IoT system.
So, choosing the right type of IoT connectivity is crucial for any IoT system.
Factors to Consider In Choosing IoT Connectivity
Above, we have discussed that there are three main factors in choosing different connectivity options: bandwidth, range, and power consumption. However, we can further expand those three, and here we will discuss the most important factors to consider when choosing your IoT connectivity solution:
- Bandwidth capacity: In an IoT system, bandwidth refers to the volume of data sent and received between the IoT devices. There are IoT systems that only need a small fraction of data every single day, and there are also use cases that need to continuously transmit a high amount of data every minute or even every second.
- Coverage range: how far away a device can be installed from your hub and/or other devices while maintaining reliability. If it’s a wired connection, then the coverage range is the length of the cable. Cellular connectivity, on the other hand, can allow miles in coverage range.
- Power consumption: since most IoT devices/sensors are battery-powered, power consumption can be a huge issue. Different IoT connectivity solutions have different power consumptions.
- Cost: an obvious factor to consider. It’s also important to note that every IoT connectivity option has the initial investment cost and ongoing operational fees (monthly data fees, subscription fees, etc.)
- Your existing system: If you can integrate the IoT system with your existing system and infrastructure, it can be a major time and resource saver.
- Place of deployment: for example, if the IoT system is going to be deployed in a location with a lot of walls, radio interferences, and other factors. Different connectivity solutions might work better in certain conditions than others.
- Scalability: how easy it is to scale the connectivity solution as your IoT system also grows. Some solutions (i.e. wired connectivity) are more rigid than others regarding scalability. It’s important to remember that switching your connectivity option mid-way can be very expensive and can be time-consuming.
Common IoT Connectivity Options and Their Benefits
Below, we will discuss some of the most common IoT connectivity options, and how they fare according to the factors we’ve discussed above.
- Cellular IoT Connectivity
In IoT implementation, cellular connectivity is also called M2M (machine to machine) cellular, and a key characteristic of cellular connectivity is its very long coverage range. You can even connect two devices in two different countries via an IoT cellular connectivity. Truphone’s IoT data plan, for example, offers coverage in 100+ different countries, so you can technically expand your IoT system to a global scale.
Cellular connectivity, with LTE and now 5G, can also offer very high bandwidth and data transfer speed. Cellular IoT always has issues with high power consumption, but there are emerging cellular technologies like NB-IoT, Cat-M1, and others that are focused on retaining the benefits of cellular connectivity while lowering power consumption.
Wi-Fi connectivity offers very high bandwidth (that is also very reliable) and consumes much less power compared to cellular connectivity. However, a key tradeoff of using a Wi-Fi solution is coverage range. So, Wi-Fi is typically only used in short-range IoT deployments like a smart home. There are, however, newer Wi-Fi technologies like HaLow that are focused on improving the range and power consumption of Wi-Fi for future IoT implementations.
- Bluetooth (LE)
Bluetooth has relatively low bandwidth capacity and very short coverage range, but with the new Bluetooth Low Energy (LE) technology, it consumes very little power. This is why Bluetooth LE is best suited for IoT use cases that transmit low data in short-range deployments, like a smart home implementation.
- Mesh technologies
Mesh technologies work by creating interconnected nodes between IoT devices/sensors to transfer data. This mesh configuration can improve coverage range and power consumption, but it can only transfer relatively small data packets. Zigbee and Z-Wave are among the most popular mesh IoT connectivity protocols and are widely used in smart home and small business IoT implementations.
LPWAN stands for Low-Power Wide Area Network, which is an umbrella term for newer connectivity technologies that are focused on IoT by improving coverage range while retaining low power consumption. Sigfox and LoRa are two of the most popular LPWAN solutions available today, but newer solutions like NB-IoT and LTE Cat-M (which are based on cellular LTE) have also gained popularity in recent years.
LPWAN solutions can offer impressive coverage of up to 25 miles between devices with very low power consumption. We can expect LPWAN and LPWAN-based cellular connectivity to be the future of IoT connectivity, but at the moment they are offering relatively low bandwidth range.
As discussed, each IoT connectivity solution offers a tradeoff between bandwidth, coverage range, and power consumption. In general, we can divide them into three main categories:
- High coverage range, high bandwidth, high power consumption: cellular connectivity belongs to this category. It is the best regarding coverage range and very reliable in high bandwidth use cases, but it takes a lot of battery power. Satellite connectivity also belongs to this category. Useful in specific use cases like when an IoT sensor must be deployed in the middle of the ocean.
- Low coverage range, high bandwidth, low power consumption: wired connection (i.e. Ethernet), Wi-Fi, and Bluetooth LE belong in this category. Great for short-range IoT deployments, but the implementations are fairly limited.
- High coverage range, low bandwidth, low power consumption: various LPWAN solutions belong in this category. Useful in IT use cases that require little bandwidth but high coverage range like deployments of sensors in the middle of nowhere