Bandwidth might be a key issue for human users of mobile and fixed networks. For most machine-to-machine applications, bandwidth is far less an issue than sensor battery life, as the amount of information often transmitted is almost trivial.
Where human smartphone requirements often are characterized by the need for scores of megabytes per second data rates, many sensor networks only need to transmit a few bytes a day to be useful.
Narrowband internet of things (NB-IoT) and LTE-M are two approaches to creating low power sensor networks supporting sensors on a 4G mobile network, emphasizing low battery consumption and low cost connectivity. But both those networks arguably are positioned in a different part of the potential market than other purpose-built machine-to-machine networks.
Some idea of the character of machine-to-machine (sensor) applications can be seen by the typical amount of data that has to be transmitted by sensors. It may remind you of paging systems, should you recall them.
Sigfox says that sending GPS location requires about six bytes, temperature just two bytes. Object status might require only a single byte, the same amount of data consumed to report speed.
That shows just how optimized a low power wide area network is for low power consumption. Where one might think kilobytes are required to report at least some types of information, other simple status updates might take even less than that.
Such networks are optimized for uplink communications only, not duplex. So sensor transmitters can be turned off when not actively uploading data. Also, many sensor apps only require that a particular sensor be turned on for a few seconds a day, says Marc Olivier, Sigfox VP.
IoT networks optimized for mobile networks feature much-higher bandwidths. M2M networks on 4G networks tend to support a few megabits per second, while 5G variants might support 10 Mbps.
You might correctly guess that such positioning means mobile M2M sensor networks might have an advantage for higher-bandwidth apps, while purpose-built LPWAN networks might have an advantage for applications where reporting requirements are quite low.