What is NB-IoT?

NB-IoT stands for “NarrowBand Internet of Things” and it’s low power wide area (LPWA) cellular radio access technology standardized by 3GPP with aim to enable a wide range of IoT devices and services.

3GPP has defined a set of frequency bands for NB-IoT use: Release 13 list consists of bands: 1, 2, 3, 5, 8, 12, 13, 17, 18, 19, 20, 26, 28, 66 and Release 14 added the bands: 11, 25, 31, 70 and by Release 15 we’ll have additional bands: 4, 14, 71.

There are three deployment modes specified by 3GPP: LTE in-band mode, LTE guard-band mode and Standalone deployment mode.

LTE in-band enables implementation of NB-IoT anywhere within the legacy LTE spectrum. Here resource blocks are used where one block is 180 kHz wide and this is the smallest resource unit that can be allocated to the user, it consist of 12 x 15 kHz sub-carriers or 24 x 7.5 kHz sub-carriers.

LTE guard-band mode uses guard-band that LTE has on each end of the band. Every band has at least 100 kHz wide guard on each end and that means we can easily have 180 kHz of space between any two non-contiguous bands for NB-IoT deployment.

Standalone mode lies on the idea of freeing up GSM channel carrier frequencies (200 kHz’ of bandwidth) and deploying NB-IoT in that spectrum, but it can also be deployed anywhere within available existing spectrum of the operator (with non standard bandwidths or by re-framing other radio access technologies).

By using licensed spectrum, NB-IoT operators can offer better reliability and QoS since it’s their own spectrum, they are not sharing it with others, and thus they have much less interference problem.

One of the key benefits for NB-IoT providers is roaming and this is done easily since they already have existing roaming agreements with different MNO’s, so they can sell their services across different countries.

There are several other benefits of using standardized LPWA technology that I didn’t mentioned yet, but these are also significantly important: better indoor penetration coverage, secure connectivity,  strong authentication, optimized data transfer by supporting different blocks of data, and data rate scalability.

NB-IoT operators can also offer different connectivity options through their IoT platforms, including device management, application enablement and data analytics.

For mobile network operators it’s essential that devices and E2E services of various vendors can connect to their NB-IoT deployed systems, so transport capability and connection modes need to be well understood. This is the baseline to achieve wide adaptation of NB-IoT services and have a stable business model. It’s importan to ephasize that operators have the licensed spectrum and with todays 4G/LTE networks only a software upgrade is needed to support NB-IoT.

As we can see on GSMA deployment map many different operators across the world are rolling out NB-IoT networks. Some of them, like Vodafone, Deutsche Telekom, Telefónica, Etisalat, KT, TDC, NOS, China Mobile, China Telecom, China Unicom did the pilots in the areas of smart agriculture, smart metering, smart parking and many other use cases where main requirements are low cost of the devices and low cost of maintenance services.

Based on the all the written facts, I see NB-IoT as a key LPWA technology to be developed upon.