2. Bluetooth Low Energy
Like WLAN, Bluetooth is a short-range solution. Bluetooth operates on licence-free frequencies between 2.4 and 2.485 GHz and it can switch between different frequencies to limit interference from other devices. This technology is energy efficient, which also limits the available bandwidth. This means users can only transport small quantities of data. Bluetooth is perfectly suited to link small electronic devices, e.g. connecting a smartphone to a wireless speaker to play music.
Furthermore, Bluetooth can be used in combination with a mobile phone that serves as a gateway. If the right app is installed on the phone, devices can exchange data with the internet via the phone. This method – known as Bluetooth Low Energy – is characterised by its extremely low energy requirements and its relatively low implementation costs. Many common devices use this technology, from toothbrushes and washing machines to kitchen appliances and even toys.
3. Cellular M2M
Cellular M2M (machine-to-machine) uses radio waves in the same way that a phone uses a SIM card. The range depends on the presence of transmitter masts; from a mast, the range is 16 kilometres. Because of the large density of transmitter masts, this technology offers global coverage. You need a SIM card to connect an object to cellular M2M. Once connected, the object will retain its connection through roaming. Audio, text messages and data can be transmitted continuously, which means the energy requirements are relatively high. This makes cellular M2M mainly suitable for wearable and easily chargeable devices. The costs per minute or MB can be high, because you use a different network.