NB-IoT event organized by Comet electronics on December 4th

NB-IoT is one of the promising LPWAN technologies I review in both my Industry 4.0 and OpenFest 2018 talks.

It’s lightweight LTE technology which has only 48 bytes of payload and 30kbps up and down link. Some call it 0G.

NB-IoT is specified by 3GPP standartization organization, same which standartize 2G/3G/4G/5G. It works flawless with existing cellular technologies with simplified RF and processing.

With these high speeds and small payloads the average consumption of NB-IoT make it more efficient even than LoRa, but there is many things to consider in your design.

First is that NB-IoT never will reach LoRa price point, it will be always about x2 more expensive.

Second – some modules like for instance the popular Ublox SARA-N2  which cost EUR 11 for 250 pcs, can’t work at lower than 2.75V power supply. Most Lithium batteries capacity is quoted with battery discharge from 3V to 2V so these modules will work only with fraction of the capacity of Lithium batteries. They are designed to operate from 2.75 to 4.2V i.e. targeting LiPO re-chargeable batteries, but these will never stay charged for 10 years as NB-IoT technology promises, so this is really odd design choice by Ublox.

Another thing to take into consideration is the high current pulses which LTE technology introduce (up to 2A when link is established). So even on paper NB-IoT to looks better than LoRa it still could be implemented with compromises where these benefits to be not seen.

Fortunately some Chinese vendors (like Quectel) made their modules BC66 to work from 2.1V.

Comet Electronics is organizing on December 4th NB-IoT event together with the first cellular operator which implements NB-IoT connectivity in Bulgaria – A1 and with Chinese module supplier Quectel.

It would be interesting to touch and evaluate this technology which is relatively new, has no infrastructure and is dependent by subscription fees only.

NB-IoT Gateways are not expensive and cost about $2000, but you can’t use them unless you have licensee to operate at GSM frequency (and these licensees cost millions of EUROs at least here in Bulgaria) so you can use your gateway only in Faraday cage :). This is where LoRa technology shine and this is what makes it so popular! No subscription, no fees for data transport, everyone can run his own gateway.

This is also one of the reason NB-IoT infrastructure is not so well developed – the investment is small, but the mobile operators still can’t figure out how to squeeze money out of this. There are already several providers on the net which sell NB-IoT SIM cards with EU roaming and with low cost like $12 per year, but local operators will find a way to shut these down and take their share.