Narrowband Internet of Things (NB-IoT) is a Low Power Wide Area Network (LPWAN) radio technology standard developed by 3GPP to enable a wide range of cellular devices and services. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016. Other 3GPP IoT technologies include eMTC (enhanced Machine-Type Communication) and EC-GSM-IoT.
NB-IoT focuses specifically on indoor coverage, low cost, long battery life, and high connection density. NB-IoT uses a subset of the LTE standard, but limits the bandwidth to a single narrow-band of 200kHz. It uses OFDM modulation for downlink communication and SC-FDMA for uplink communications. 
3GPP Narrowband Cellular Standards
|LTE Cat 1||LTE-M||NB-IoT||EC-GSM-IoT|
|LTE Cat 0||LTE Cat M1||LTE Cat M2||non-BL||LTE Cat NB1||LTE Cat NB2|
|3GPP Release||Release 8||Release 12||Release 13||Release 14||Release 14||Release 13||Release 14||Release 13|
|Downlink Peak Rate||10 Mbit/s||1 Mbit/s||1 Mbit/s||250 kbit/s||474 kbit/s (EDGE)
2 Mbit/s (EGPRS2B)
|Uplink Peak Rate||5 Mbit/s||1 Mbit/s||1 Mbit/s||250 kbit/s (multi-tone)
20 kbit/s (single-tone)
|474 kbit/s (EDGE)
2 Mbit/s (EGPRS2B)
|Number of Antennas||2||1||1||1||1–2|
|Duplex Mode||Full Duplex||Full or Half Duplex||Full or Half Duplex||Half Duplex||Half Duplex|
|Device Receive Bandwidth||1.4 – 20 MHz||1.4 – 20 MHz||1.4 MHz||180 kHz||200 kHz|
|Receiver Chains||2 (MIMO)||1 (SISO)||1 (SISO)||1 (SISO)||1–2|
|Device Transmit Power||23 dBm||23 dBm||20 / 23 dBm||20 / 23 dBm||23 / 33 dBm|
- 149 operators in 69 countries investing in one or both of the NB-IoT and LTE-M network technologies
- 104 of those operators in 53 countries had deployed/launched at least one of the NB-IoT or LTE-M technologies of those, 20 operators in 19 countries had deployed/launched both NB-IoT and LTE-M
- 22 countries are now home to deployed/launched NB-IoT and LTE-M networks
- 29 countries are home to deployed/launched NB-IoT networks only
- Two countries are home to deployed/launched LTE-M networks only
- 141 operators in 69 countries investing in NB-IoT networks; 90 of those operators in 51 countries had deployed/launched their networks
- 60 operators in 35 countries investing in LTE-M networks; 34 of those operators in 24 countries had deployed/launched their networks
Devices and modules
The 3GPP-compliant LPWA device ecosystem continues to grow. In April 2019, GSA identified 210 devices supporting either Cat-NB1/NB-2 or Cat-M1 – more than double the number in its GAMBoD database at the end of March 2018. Specifically, GSA logged 156 modules supporting both Cat-NB1, NB2, or Cat-M1 (including known variants); 100 modules supporting Cat-M1 (including known variants); and 103 modules supporting Cat-NB1 or NB2 (including known variants).
- LoRa / LoRaWAN
- LTE User Equipment Categories
- LTE sidelink
- "NarrowBand – Internet of Things (NB-IoT)".
- Grant, Svetlana (September 1, 2016). "3GPP Low Power Wide Area Technologies - GSMA White Paper" (PDF). gsma.com. GSMA. p. 49. Retrieved October 17, 2016.
- "Standardization of NB-IOT completed". 3gpp.org. 3GPP. June 22, 2016. p. 1. Retrieved August 19, 2016.
- "Extended Coverage - GSM - Internet of Things (EC-GSM-IoT)". gsma.com. GSMA. May 11, 2016. p. 1. Retrieved October 17, 2016.
- Lawson, Stephen (September 21, 2015). "NarrowBand IoT standard for machines moves forward". computerworld.com. Computerworld / IDG. p. 1. Retrieved September 24, 2015.
- Jones, Dan (September 11, 2015). "Ericsson, Intel, Nokia Back New Narrowband LTE IoT Spec". lightreading.com. LightReading. p. 1. Retrieved September 24, 2015.
- Scales, Ian (September 18, 2015). "3GPP agrees 'harmonized' proposal for narrowband IoT radio technology". telecomtv.com. TelecomTV. p. 1. Retrieved September 24, 2015.
- Lawson, Stephen (September 22, 2015). "LTE standard for Internet of Things machines gets the green light". PCWorld / IDG. p. 1. Retrieved September 24, 2015 – via pcworld.com.
- GSA: Global Narrowband IoT – LTE-M networks – March 2019 (retrieved 27 March 2019)
- "Preliminary specification". 3GPP.
- Luo, Chao (March 20, 2017). "3GGP TS45.001: GSM/EDGE Physical layer on the radio path" (ZIPped DOC). 3gpp.org. 14.1.0. 3GPP TSG RAN WG6. p. 58. Retrieved May 27, 2017.
- GSA: Global Narrowband IoT – LTE-M networks – March 2019 (retrieved 25 March 2019)
- GSA: NB-IoT and LTE-M: Global Ecosystem and Market Status, April 2019 (retrieved 24 April 2019)