What is LTE Cat M1?

What is LTE Cat M1 and how is it different from NB-IoT?
1 Answer
Can you answer this question?

- everything RF

Feb 7, 2023

LTE Cat M1 is a cellular LTE technology specifically designed for the Internet of Things (IoT) and machine-to-machine (M2M) communications. It is a low-power wide-area (LPWA) cellular technology that has been developed by 3GPP as part of the 13th edition of the LTE standard. It supports low to medium data rate applications with an upload/download data rate of less than 1 Mbps and can be used in both Half Duplex or Full duplex modes.

LTE Cat M1 operates using existing LTE networks, however, unlike NB-IoT which operates using unused spectrum or the guard bands, LTE Cat M1 operates within the same LTE band used for cellular applications. This is advantageous to most carriers as they don’t need to spend resources to create new antennas. They simply have to upload new software as long as the devices operate within their LTE network. Since this technology co-exists with 2G, 3G, and 4G mobile networks it has the benefits of all the security and privacy features of mobile networks, such as support for user identity confidentiality, entity authentication, confidentiality, data integrity, and mobile equipment identification.

LTE Cat M1 is a complementary technology to NB-IoT, with faster upload and download speeds of 1 Mbps and lower latency of 10 to 15 ms. It requires a total bandwidth of 1.4 MHz and operates in both Half Duplex or Full duplex modes. One of the advantages that LTE Cat M1 has over NB-IoT is the ability to hand over from cell site to cell site, which makes it possible to use this technology in mobile applications. NB-IoT does not allow porting from cell site to cell site and therefore can only be used for fixed applications i.e those that are limited to the coverage area of a single cell site. In LTE, different categories have differing data speeds, frequency spectrum, power usage and signal range. The different LTE categories can be chosen depending on the trade-offs to be made, in other words, some aspects can be given up in order to gain advantages in another aspect. LTE Cat M1 trades in the high data rate delivered by LTE for better power efficiency and longer signal range and is therefore considered an "Internet of Things" (IoT) cellular technology. The lower data rates mean that the signal can travel further and it will take less power to do so.

LTE Cat M1 Specifications

3GPP ReleaseRelease 13
Device Receive Bandwidth
1.4 MHz
Downlink Peak Rate
1 Mbit/s
Uplink Peak Rate
1 Mbit/s
Latency10-15 ms
Power Requirement
Very low
Duplex Mode
Full/Half duplex
Device Transmit Power
20/23 dBm

Advantages of LTE Cat M1

LTE Cat M1 devices have significant advantages for mobile network operators (MNOs), IoT developers, and also customers:

  • The key advantage of LTE Cat M1 devices for MNOs is that they operate on considerably lower frequency bands (1.4 MHz). This allows them to add more devices into each cell site’s accessible spectrum. In comparison to active standard LTE devices, a typical LTE cell site can accommodate 10x the quantity of active Cat M devices.
  • LTE Cat M1 modems require less power, allowing power-constrained devices can function for months or years on a tiny battery with sophisticated power-saving capabilities.
  • LTE Cat M1 modems also start up faster from a cold start than Cat-1 modems, resulting in faster connection times.
  • Another significant benefit is that LTE Cat M1 modems are typically less expensive than normal LTE modems, lowering hardware costs.

Drawbacks of LTE Cat M1

While LTE Cat M1 offers considerable potential for power-constrained IoT devices, it also has several disadvantages.

  • LTE Cat M1 has limited bandwidth. Some testing reveals that normal upstream rates are approximately 300 Kbps, even though LTE Cat M1 offers peak upstream speeds of around 1 Mbps.
  • In the event of network congestion, devices employing LTE Cat M1 might be moved off the network. When a cell site becomes overcrowded, the network will require Cat M1 devices that have been connected for a long period to disengage and reconnect later.

Applications of LTE Cat M1

LTE Cat M1 is best suited for IoT devices that are power-constrained and exchange limited volumes of traffic with the application. Here are a few examples of possible applications:

  • Asset management
  • Smart meters (temperature, air quality meter, etc.)
  • Smart irrigation
  • Vehicle/fleet tracking
  • Financial companies
  • Car rental
  • Personal/Asset Trackers
  • ATMs
  • Sensor Nodes
  • Utility Meters
  • Monitoring Systems
There are a number of other LPWA Technologies that are also being considered for IoT Applications. Another popular ones is NB-IoT (Narrowband IoT) - Click here to learn about this technology.