LTE M2M (LTE-M)
The Internet of Things( IoT) and the machine-to-machine( M2M) communications associated with it have led to the development of cellular LTE-M, also known as LTE- MTC, Machine-Type Communications (MTC), by 3GPP. In general, traffic could be handled over an LTE network, but Long Term Evolution (LTE) is designed for high data rates, which is why LTE-M, a variant for Low Power WANs( LPWAN), was developed for M2M communications at low data rates. Narrow Band LTE( NB-LTE) is a further developed concept.
LPWANs are designed to have the lowest possible energy consumption so that the battery life of the sensors and actuators lasts several years if possible. For this reason, low data rates are also used. These are 200 kbit/s, as opposed to 1 Mbit/s for LTE. Another aspect of M2M communication is the bridging of greater distances.
LTE M2M must support a wide variety of devices and equipment in the Internet of Things. These range from smart power devices to smart meters, automotive fleet management, and medical devices for patient monitoring. One of the key development goals is to achieve the longest possible battery life, which may well be ten years, so that the various battery-powered devices can operate for years without requiring maintenance. In addition, LTE-M networks must support an enormous number of components. To generate the lowest possible energy consumption, bidirectional communications can also operate in half- duplex at low data rates. Energy consumption is also greatly limited by Extended DRX (eDRX) and Power Saving Mode( PSM).
LTE-M transmits in the sub- GHz range between 700 MHz and 900 MHz. 3GPP has specified Release 12 and Device Category 0 for these requirements. This configuration supports data rates of 1 Mbit/s in both the downlink and the uplink. Release 13 specifies a channel width of 1.4 MHz and a transmission line of 20 dBm.