LTE-M
LTE-M (or eMTC or CatM1) is designed for low power applications requiring medium throughput. It has a narrower bandwidth of 1.4 MHz compared to 20 MHz for regular LTE, giving longer range, but less throughput. The throughput is 375 kbps downlink and 300 kbps uplink, providing 100 kbps application throughput running IP. It is suitable for TCP/TLS end-to-end secure connections. Mobility is fully supported, using the same cell handover features as in regular LTE. It is currently possible to roam with LTE-M, meaning it is suitable for applications that will roam across multiple regions. The latency is in the millisecond range offering real time communication for time critical applications. LTE-M is perfect for medium throughput applications requiring low power, low latency and/or mobility like asset tracking, wearables, medical, POS and home security applications.
NB-IoT
NB-IoT (also known as Cat-NB1) is a narrowband technology standard that does not use a traditional LTE physical layer, but is designed to operate in or around the LTE bands and co-exist with other LTE devices. It has a bandwidth of 200 kHz, giving it longer range and low throughput compared to LTE-M and LTE. The throughput is 60 kpps downlink and 30 kbps uplink. It is suitable for static, low power applications requiring low throughput. NB-Iot is perfect for static, low throughput applications requiring low power and long range, like smart metering, smart agriculture and smart city applications.