If you’ve been researching cellular communication you’ve probably encountered a flood of terminology. You’re likely familiar with terms like 4G and 4G LTE, but what is LTE-M?
Let’s start with the basics. 4G stands for the fourth generation of cellular connectivity. A 4G wireless network is supposed to have peak download speeds of 1GB/sec. This represents a massive improvement from 3G networks that had peak download speeds of a few MB/sec.
LTE (Long Term Evolution) is one of many technologies for implementing a 4G network -- others include WiMAX and HSPA+ -- and is by far the most widely used by US carriers. It was developed by a global organization called 3GPP (3rd Generation Partnership Project). Every few years, 3GPP publishes new enhancements to this LTE technology called “releases” Introduced in Release 13, LTE-M (also known as CAT M1) is a communication standard geared towards IoT devices.
While most 3GPP releases aim to increase the amount of data being sent between your phone (or in this case, your IoT device), LTE-M dramatically reduces the data uplink/downlink rate to 1MB/sec. Why? By decreasing the amount of data sent, devices using LTE-M technology can achieve remarkably long battery lives (several years) while still maintaining long range communication. For those familiar with the term, it qualifies as a Low Power Wide Area (LPWA) connectivity method and represents a competitor to non-cellular LPWA networks like LoRaWAN and Sigfox.
LTE-M is especially unique for the techniques used for minimizing power consumption. Low power consumption is crucial for any IoT device that runs on battery power. If you had to recharge your IoT devices every day (like you do with your phone), a large scale deployment would be impossible.
Finally, LTE-M also supports voice functionality (VoLTE) which opens the technology up to many new use cases. For instance, home security systems equipped with LTE-M could process sound data and alert the homeowner if suspicious noises are detected.
Conclusion
LTE-M is a promising competitor to existing LPWA technologies for IoT. It solves the battery life problem with existing cellular connectivity methods and has the added benefit of being compatible with current cellular networks. Stay tuned for the next installment of our Introduction to LTE-M where we'll cover optimal use cases for this technology.