What is NB-IoT?

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- everything RF

Feb 7, 2023

NB-IoT or Narrowband IoT, also known as LTE Cat NB1 is a Low Power Wide Area (LPWA) Technology that has been developed by 3GPP for IoT Applications. It is a cellular LPWAN technology that uses existing cellular networks for wireless communication. NB-IoT is a low power, narrow band technology that can handle small amounts of 2-way data transmission in an efficient, secure and reliable manner.

The specifications of NB-IoT were introduced in ‘release 13’ as LTE Cat-NB1 and then later with release 14, enhanced specifications were added to it and were called LTE Cat-NB2. NB-IoT is very similar to LTE Cat M1 in that it's designed mainly for IoT devices and therefore prioritizes signal distance and lower power usage over data speeds. NB-IoT goes further with this trade-off and achieves more distance and lower power by using even lower data speeds than LTE Cat M1. NB-IoT features uplink speeds of 66 kbps and download speeds of 26 kbps in half-duplex mode which means that data goes in one direction at a time. It also has a latency of 1.6 to 10 seconds. NB-IoTuses OFDM modulation for downlink communication and SC-FDMA for uplink communications.

NB-IoT uses a subset of the LTE standard but limits the bandwidth to a single narrow band of 200 kHz. It usually operates in a very narrow bandwidth – 180 kHz – and can be deployed in the guard band portion of an LTE network, which is in-between channels in an unused portion of the spectrum. Due to this, NB-IoT excels for IoT projects with a vast coverage area, delivering up to seven times the range of other technologies like LTE Cat M1

IoT applications that require more frequent communications will be better served by NB-IoT which has no duty cycle limitations operating on the licensed spectrum. NB-IoT relies on simple waveforms for connectivity, which consumes very little power compared to LTE Cat M1. NB-IoT devices can also offer better building and obstacle penetration.

NB-IoT significantly improves the power consumption of user devices, system capacity and spectrum efficiency, especially in deep coverage. Battery life of more than 10 years can be achieved using NB-IoT for a wide range of use cases. Supported by all major mobile equipment, chipset and module manufacturers, NB-IoT can co-exist with 2G, 3G, and 4G mobile networks. It also benefits from all the security and privacy features of mobile networks, such as support for user identity confidentiality, entity authentication, confidentiality, data integrity, and mobile equipment identification.

Specially designed devices and sensors are the basic components of NB-IoT systems. These devices collect information from their surroundings and transmit it to NB-IoT base stations or transmission nodes. Individual base stations are connected to an IoT gateway and IoT cloud application servers for centralized monitoring and data analysis.

As opposed to LTE Cat M1, NB-IoT has no full support for mobility. NB-IoT is more prevalent in applications and use cases with fixed (stationary) assets and devices. This doesn't mean that NB-IoT can’t be used for assets and devices that are mobile; it’s just limited. In NB-IoT, the device needs to reselect the cell as it travels which is not the case with LTE Cat M1. So, it’s far less suited for mobile. The reselection of cells also has an impact on battery life as it consumes more power to repeatedly reselect cells on the move.

The NB-IoT technology operates using resource blocks on existing LTE networks or in the LTE carrier's guard bands. It can also operate using unused 200 khz bands that were previously used by GSM.

Key NB-IoT Specifications

3GPP ReleaseRelease 13 (Cat NB1)Release 14 (Cat NB2)
Downlink Peak Data Rate26 kbit/s127 kbit/s
Uplink Peak Data Rate66 kbit/s (multi-tone)
16.9 kbit/s (single-tone)
159 kbit/s
Latency1.6-10 ms1.6-10 ms
Receive Bandwidth180 kHz180 kHz
Transmit Power20/23 dBm14/20/23 dBm
Duplex ModeHalf DuplexHalf Duplex
Support for Voice (VoLTE)

Advantages of NB-IoT:

  • Ubiquitous coverage and connectivity - NB-IoT can help support massive numbers of devices by establishing NB-IoT networks that can connect to billions of nodes. Designed for extended coverage indoors, the lower complexity of the devices provides long-range connectivity and communication.
  • Low power consumption - NB-IoT doesn't need to run a heavy operating system, such as Linux, or do a lot of signal processing, which makes it more power efficient compared to other cellular technologies. NB-IoT devices have much lower complexity 
  • Low cost of devices - Because it's easier to create devices with lower complexity, the cost of the devices is significantly low, around $5 per module.
  • Multiyear battery life - The enhanced power consumption capability enables NB-IoT to support a multiyear battery life for devices.
  • Security - NB-IoT is secured much like 4G, including all encryption and SIM-based authentication features.

Application-of-NB-IoT copy

Applications of NB-IoT

Most common applications for NB-IoT include smart gas, water, and electricity meters, smart city applications, such as smart street lighting and parking sensors, and other remote sensing applications that don’t send frequent or large amounts of data. This also includes HVAC control, industrial monitors, and agricultural sensors that monitor irrigation systems and detect leaks. Other applications of NB-IoT include:

  • Smart Cities - Static applications with low bandwidth requirements such as smart parking, noise, pollution monitoring, waste management, and smart traffic monitoring. NB-IoT can help local governments control street lighting, determine when trash bins must be emptied, identify free parking spaces, monitor environmental conditions and survey road conditions.
  • Smart Agriculture - Stationary applications with low bandwidth requirements such as weather stations, soil moisture/temperature, and humidity levels, and other environmental applications. NB-IoT connectivity enables farmers and cities to capture data from environmental sensors containing NB-IoT modules that can send alerts if anything out of the ordinary happens. These sensors could be used to monitor the temperature and humidity of the soil, as well as to track the attributes of land, pollution, noise and rain.
  • Smart buildings - NB-IoT sensors can send alerts to facilities managers regarding building maintenance issues. There are also indoor temperature monitoring systems that are based on NB-IoT sensors. NB-IoT can serve to back up a building's broadband connection.
  • Tracking - NB-IoT provides a secure, inexpensive way to track people, animals and assets when continuous tracking isn't necessary. NB-IoT is good for tracking objects that may not be moving all the time.
  • Logistics & Transportation - Semi-stationary assets such as commercial refrigeration equipment (ice cream, beverages, etc.) and on-site logistics equipment (racks, trolleys, lifts, and other warehouse machinery).
  • Industrial & Manufacturing - Stationary machinery with low data rates for process variables indirectly affecting production or quality, industrial assets tracking, and energy monitoring.

There are a number of other LPWA Technologies that are also being considered for IoT Applications. Another popular one is LTE CAT M-1 - Click here to learn about this technology.