Understanding 4G LTE Categories

LTE consists of a range of different categories of modem, which can be integrated into telematic devices. These different categories include:

    • CAT NB1 (also referred to as NB-IoT)
    • CAT M1 (also referred to as CAT M)
    • CAT 1
    • CAT 4

Although cellular technologies go from CAT 0 to CAT 19, these are the technologies commonly used for telematic and connected vehicle applications. In general, as you progress down the list above, the power consumption, throughput, and price of the devices increases (all considerably). When comparing specifications and capabilities of different telematic devices, it can be difficult to know what is the right level of capability for your cellular data transfer needs. This post will provide a brief summary and application-level insight to this area of potential confusion when specifying or purchasing telematic products.

NB-IoT and M1

Firstly, although these newer, low-energy cellular technologies are grouped together, they are not exactly the same thing. Most hardware that supports one also supports the other, so you can prototypically get both capabilities in a single package. This is new and cool, and will continue to grow in things it can accomplish within the geographies where it can be deployed.

Although you’ll hear NB-IoT and M1 discussed in the context of vending machines, pollution monitors, electric meters, and wearables, these technologies absolutely have a role to play in mobile vehicles and equipment. Here is what’s great about both NB-IoT and M1:

  • Very low power
  • Provide superior range over CAT 1 and CAT 4 modems (in our testing NB-IoT and M1 devices frequently have cellular connectivity in areas where cell phones do not)
  • Lowest cost of any cellular components or data plans
  • In the case of M1, deploys using existing cellular infrastructure, so lots of new support is expected to come online
  • Secure

As my mother always told me growing up, nothing is free. There’s a trade-off for the lower power consumption, lower price, and improved range of the NB-IoT and M1 technologies. Here’s what you spend to get that goodness:

  • Lower data rate (~375 kbs) in typical half duplex configuration
    • Can achieve up to 1 Mbps in full duplex
  • Higher latency for wake-up applications

If you have a few sensor parameters, or a couple of buses of CAN data, to send on M1 is a great technology for mobile applications. One thing to note is that NB-IoT is not as friendly for “on-the-go” applications, and really expects the modem to stay in the vicinity of a single tower. M1 is intended for applications where the modem is mobile, moving from tower to tower.

CAT 1

This is the bread and butter of telematic connectivity technologies. LTE CAT 1 is capable of supporting feature-rich telematic products with enough throughput to support streaming meaningful amounts of data while vehicles are on the go. The maturity of the technology makes it broadly available in a large number of geographies, with mature modem hardware and firmware support and a full-featured build-out of carrier capabilities. This technology is a little more expensive than NB-IoT and M1, but has the following advantages over those technologies:

  • Higher data streaming throughput (up to 10 Mbs)
  • Lower latency for wake-up applications
  • Broader global coverage

If you need to deploy a solution broadly for mobile equipment (touching dozens of countries), need to offload a fairly large amount of machine data in a hurry, or require support for streaming video or other data-intensive content, then CAT 1 is going to be the way to go for your application.

CAT 4

LTE CAT 4 modems can absolutely scream data. These modems can hit 150 Mbs, more than ten times the throughput of their CAT 1 counterparts.

They are also complex, expensive, require multiple antennas, and are power hungry. These modules are typically reserved for spaces like the handset market. Unless you need to aggregate a lot of data from a lot of machines, or provide streaming services to a large number of passengers onboard a vehicle, it is unlikely that the cost or complexity of this technology will be appropriate for your mobile application. 


David Batcheller – President & CBO