What Is LTE-M in IoT Connectivity?

LTE-M, short for Long Term Evolution Machine Type Communication, is a specialized 4G cellular network designed specifically for the Internet of Things (IoT). It offers two main versions: Cat-M1 and Cat-M2. These Low Power Wide Area Networks (LPWANs) provide cost-effective and efficient connectivity for IoT applications. Through features like Power Saving Mode (PSM) and Discontinuous Reception (DRX), LTE-M devices can achieve battery lifespans of 10 years or more. LTE-M is a branch of LTE technology created for Machine-to-Machine communication. It allows IoT devices to transmit and receive substantial amounts of data while minimizing battery drain, unlike 2G, 3G, and 4G networks. 

Major LTE-M Specifications 

• Power consumption. Unlike traditional cellular networks designed for smartphones, LTE-M addresses the unique power requirements of IoT devices. It eliminates battery drain caused by frequent location updates, allowing devices to "sleep" when not in use. Additionally, LTE-M incorporates extended Discontinuous Reception (eDRX), increasing the intervals for checking the radio and reducing power consumption.  

• Coverage. LTE-M/Cat-M1/Cat-M2 networks can leverage existing 4G LTE infrastructure, giving them a significant advantage. As over 50 percent of global mobile connections utilize 4G networks, with projected 95 percent coverage by 2026, LTE-M offers extensive coverage and improved indoor penetration. Its Maximum Coupling Loss (MCL) of 156 decibels (dB) provides robust signal strength, even in the presence of obstacles.  

• Speed. While LTE-M is not as fast as LTE, its data speed of 1 Megabit per second for both uplink and downlink transmissions surpasses older networks like 2G and 3G (UMTS) and other LPWANs. For most IoT applications, this speed is more than sufficient, enabling tasks such as Over-the-Air (OTA) updates and video streaming.  

• Mobility. With low latency of 10-15 milliseconds and support for cell handovers, LTE-M is ideal for mobile IoT applications like asset tracking, fleet management devices, and wearables. It ensures seamless connectivity and reliable performance while on the move.  

LTE-M vs. NB-IoT: Technology Comparison 

LTE-M: 

• Maximum Uplink Speed: 1 Mbit 

• Maximum Downlink Speed: 1

• Mbit Latency: 10-15 ms 

• Maximum Coupling Loss (dBs): 156 

• Bandwidth: 1.4 MHz to 5 MHz  

NB-IoT: 

• Maximum Uplink Speed: 127 Kbit 

• Maximum Downlink Speed: 159 Kbit 

• Latency: 1.6-10 s 

• Maximum Coupling Loss (dBs): 164 

• Bandwidth: 180 KHz