Cellular (mobile networks) can be a great connection option for IoT devices. It is particularly useful for two reasons. First, cellular service is available nearly everywhere. This makes cellular ideal for mobile IoT devices. Second, all network setup can be completed at the time of manufacture. This makes deployment easy, hassle-free, and can lower ongoing support costs when compared to other options.

The drawback to cellular connectivity is higher cost. First, the IoT device must contain a cellular modem. Cellular modems are costlier than Wi-Fi modems and Ethernet transceivers. In addition, certain testing and certification is required before a device is allowed on operator networks.

Cellular devices must also pay for access. With Wi-Fi or Ethernet, an IoT device is assumed to be able to leech off local internet access. With cellular, someone must pay the bill for each specific device. Usually, it makes sense for the IoT device manufacturer to provision and maintain service for each device. For devices requiring low bandwidth, an LTE cellular connection can be maintained for well under $1.00 (USD) per device per month. Any device that requires significant bandwidth is much more costly to service.

An additional benefit of cellular is that many mobile network providers can route your traffic through a Virtual Private Network (VPN). This is done by the network operator, and you won't be billed for the additional bandwidth of the VPN overhead. A VPN isolates your IoT devices from the internet and allows communication only with your trusted servers. It is convenient because many of your security concerns are taken care of by the cellular provider.

We've covered three options for direct internet access, but many IoT devices don't need to access the internet directly. Some work in conjunction with a computer or smartphone for access. One wireless technology commonly used with this method is Bluetooth.