Cellular networks offer low latency connectivity with high download speeds and is built to cater consumer and businesses high bandwidth demands. Existing cellular network technologies such as 2G, 3G, 4G LTE work well for Internet of Things (IOT) devices and Machine-to-Machine (M2) connectivity, however these technologies are expensive and power-hungry. Cellular networks were the most common method of connectivity used for IOT devices until recently.
Although most IOT devices work well with intermittent low bandwidth connections it is important to take into consideration and review mobility, latency, throughput, coverage, and battery life requirements for your IOT projects.
LTE-M and Narrowband IOT (NB-IOT) technologies are the two main dedicated IOT specific connectivity options available for IOT devices.
The difference:
NB-IOT is developed for large scale low bandwidth IOT use cases and huge network of sensors. NB-IOT offers data transfer speeds up-to 200 kilobits per second using 200 kilohertz of cellular bandwidth.
Thousands of devices can connect simultaneously to a single base station. Although devices can be moved between locations It will not perform well when moving around constantly. Some NB-IOT use case examples are smart meters, home automation switches and sensors.
LTE-M or CAT-M is developed on the existing LTE networks and works well for IOT use cases where devices go into sleep mode between connections or are constantly on the move. LTE-M offers data transfer speeds up-to 1 megabit per second using 1.4 Mhz of cellular bandwidth.
LTE-M works with the same standards as LTE for roaming between locations when devices move between cell towers frequently. Some examples of use-cases where the devices move frequently are GPS Tracking, Vehicle Tracking, Pet Tracking.