IoT is a catch-all acronym for diverse sectors and geographies with very different connectivity requirements and that is reflected in what looks like a very confused big picture of connectivity. Drill down though, by region and sector, and some clearer threads emerge dictated by applications, device capabilities and communication characteristics. The principal candidates are 4G, 5G and the four low power WAN protocols LTE-M, NB-IoT, LoRa and Sigfox, the first two of which are based on 3GPP standards. There is a bit of overlap here, because LTE-M can be regarded as a low bit-rate variant of 4G. Under successive 3GPP 4G releases up to Release 11, 20 different categories of LTE user equipment (UE) eventually emerged, from Cat-0 to Cat-19.…