NB-IoT
LPWAN & Long Range · 7 specs
Direct Answer
Narrowband IoT (NB-IoT, standardized as 3GPP LTE Cat-NB1 in Rel-13 and Cat-NB2 in Rel-14) is a licensed cellular LPWAN standard. Utilizing a single 180 kHz PRB (Physical Resource Block), it delivers up to +20 dB coverage enhancement over standard LTE, enabling deep indoor penetration for underground water meters, smart grids, and smart cities.
Source: 3GPP Release 13–15 / GSMA Mobile IoT · Last reviewed Aug 28, 2026
Specs
| 3GPP Specification | Release 13 (Cat-NB1) / Release 14 (Cat-NB2) |
| Carrier Channel Bandwidth | 180 kHz (equivalent to 1 standard LTE PRB) |
| Deployment Modes | In-Band (within LTE carrier), Guard-Band (LTE edge), Standalone (re-farmed GSM 200 kHz) |
| Peak Data Rates (Cat-NB2) | Up to 127 kbps Downlink / 159 kbps Uplink |
| Link Budget / Coverage Gain | 164 dB (+20 dB gain over standard cellular) |
| Power Saving Features | PSM (Power Saving Mode) and eDRX (extended Discontinuous Reception) |
| Connected Node Density | Up to 100,000 devices per cell |
Deep Coverage Penetration (+20 dB)
NB-IoT achieves an exceptional Maximum Coupling Loss (MCL) of 164 dB by narrowing transmitter energy into 180 kHz and using massive subframe repetition (up to 128 repetitions on uplink). This +20 dB link budget advantage allows signals to penetrate through multiple basement concrete walls, manholes, and underground utility pits where standard 4G LTE modems fail.
Sleep Optimization: PSM and eDRX
NB-IoT modems can enter deep Power Saving Mode (PSM), shutting down RF transceivers while maintaining network registration for up to 410 days. The device only wakes up periodically or upon an external sensor trigger, enabling smart utility meters to run for 10 to 15 years on a single lithium battery.