What is NB-IoT?

NB-IoT leverages existing LTE networks, inheriting their proven mechanisms, such as communications and device security (including SIM cards) and international mobility (through roaming). In terms of security, the LTE standard natively guarantees integrity monitoring (to ensure data is not modified or tampered with) and data confidentiality, for example, through encryption.

Building on existing mobile network infrastructure, such as relay stations and capillary transmission networks spread throughout France, NB-IoT benefits from the extent of existing 4G coverage.

How does NB-IoT work?

This technology can operate in three different ways:

• "In band", replacing LTE block resources,
• "Guard band", used in the guard band at the edge of LTE blocks.
• "Standalone", on an independent 200 kHz carrier.

Unlike LTE-M, NB-IoT is not based on the IP protocol but still uses a message-based protocol. Its advantage is that it offers a faster modulation rate than LoRa or Sigfox. It can therefore exchange a larger amount of data at a slower rate.

Technically, NB-IoT uses a bandwidth of 200 kHz and OFDM modulation for incoming communications and SC-FDMA for outgoing communications. By design, it is not intended to have response times in the order of milliseconds. It allows download and upload speeds of 20 to 250 kbps with a latency of less than approximately 10 seconds. Latency will depend on the quality of the communication chip, the network, the reception quality, and the distance from the nearest antenna.

Offering bidirectional communication between a connected object and a server, NB-IoT allows, with an average data rate of 150 kbps, the regular transmission of information without usage limits. The data transits through the LTE core network before being stored on target servers (clients or hosted by the operator).

The simplicity of the standard on which this technology is based allows for the creation of inexpensive communication chips. Indeed, a chip that supports only NB-IoT is much less expensive to produce than a module that implements LTE-M, for example. Moreover, its ultra-low-power design represents a further substantial cost savings.

Unlike Sigfox and LoRaWAN technologies, for example, there is no need for a gateway for this technology to work: the 4G antennas used receive an update to support the new protocol.