NB-IoT - Narrow band IoT – is a standard for devices with low bandwidth requirements used in cellular networks. The standard is developed and supported by 3GPP, a committee formed by leading cellular network equipment vendors and service providers. The first version of NB-IoT standard was released in 2016, the standard is widely adopted by leading service providers across the globe.
The NB-IoT standard is an extension of LTE that allows to build LPWAN (low power wide area networks) over existing cellular networks, It comes as an answer to the popularity of LPWANs working in unlicensed (ISM – industry, scientific and medical) bands.
For NB-IoT network a cellular service provider must select some narrow bands on existing LTE base stations. The NB-IoT can be deployed as a part of band, occupy the whole band or use the guard band. NB-IoT devices are authenticated in a same way as traditional cellular phones and then can exchange the information with a network.
NB-IoT devices can use IPv4, IPv6 or non-IP data delivery (without IP stack on the end node). In case of IP data transport, the device can be considered as Internet-connected device and can exchange the data directly with application servers. In case of Non-IP Data Delivery a special elements inside a service provider network called SCEF or P-GW are responsible for the information exchange with the end node, IP stack is being added by these elements.
Compared to typical 2G, 3G or 4G cellular end nodes, NB-IoT standard is more energy efficient because of low data transmission speed. the energy consumption of NB-IoT device is closer to the consumption of a typical LPWAN node.
The standard allows device to transmit the data with long pauses without losing network registration. NB-IoT devices are allowed either to sacrifice receive window between transmissions to increase the battery life or it. That mechanism is similar to class A device behaviour in LoRaWAN networks. Data, transmitted by the end node, is stored on the network elements until the next data transmission. The transmission schedule is controlled by the network, it allows efficient network capacity management for a cellular service provider.
Similar to the cellular phones, NB-IoT devices are authentificated with standard SIM cards.
NB-IoT provides same transport layer security as a cellular network. Standard does not define any security mechanisms for the applications leaving that on the application developers.
Thanks to the growing adoption from the cellular service providers across the globe, NB-IoT can increase the penetration of energy efficient IoT devices and thus open the new IoT applications in different areas.