Short answerThe LTE category sets a modem’s maximum theoretical speed. Cat 1 suits low-data devices, Cat 4 suits most routers, Cat 6 and above add carrier aggregation for higher speeds, and LTE-M and NB-IoT are low-power options for sensors. Real-world speed depends on the signal and the network far more than the category.
Every 4G router datasheet lists an LTE category. It is a quick way to compare modems, as long as you remember the figures are theoretical peaks that you will rarely see.
The categories at a glance
| Category | Peak download | Peak upload | Typical use |
|---|---|---|---|
| NB-IoT | Tens of kbps | Tens of kbps | Battery sensors, meters |
| LTE-M (Cat M1) | About 1 Mbps | About 1 Mbps | Trackers, alarms, low-power devices |
| Cat 1 / Cat 1bis | 10 Mbps | 5 Mbps | Payments, telemetry, small gateways |
| Cat 4 | 150 Mbps | 50 Mbps | Most business 4G routers |
| Cat 6 | 300 Mbps | 50 Mbps | Offices, CCTV, failover |
| Cat 12 | 600 Mbps | 100 Mbps | Heavier office use |
| Cat 18 | 1.2 Gbps | 150 Mbps | High-end 4G routers |
The categories are defined by the 3GPP standards body; see 3gpp.org.
What the higher categories add
Above Cat 4, the extra speed comes mainly from carrier aggregation: using two or more bands at once. That only helps if the network offers those band combinations at your mast. In a rural area served by one band, a Cat 6 router may perform much like a Cat 4. Router Store explains the benefits of Cat 6 LTE.
Cat 1 and Cat 1bis
Cat 1 became the standard replacement for 2G and 3G modules in low-data equipment. Cat 1bis is the same speed using a single antenna, which makes devices smaller and cheaper. Both are plenty for payments and telemetry.
LTE-M and NB-IoT
These are designed for devices that send small amounts of data and must last years on a battery. LTE-M supports movement and can carry voice; NB-IoT is aimed at static devices with very low data. Support depends on the network and the SIM, so check both before choosing a module. See IoT SIMs.
Choosing
- Telemetry, alarms, payments: Cat 1 or Cat M1.
- General business router, CCTV viewing, backup: Cat 4.
- Office main connection or many users: Cat 6 or higher, or 5G.
Browse Cat 6 routers or the full range of 4G routers, and see our router checklist.
Frequently asked questions
Is Cat 6 always faster than Cat 4?
Only where the network supports carrier aggregation at your location. Otherwise they can perform about the same.
Is Cat 1 enough for a router?
For a few devices sending small amounts of data, yes. For browsing or CCTV, choose Cat 4 or above.
What replaced 2G modules?
Mostly LTE Cat 1, Cat 1bis and LTE-M, depending on data and power needs.
NANick Appleby
Nick Appleby has worked in UK telecoms since 1998, starting at BT, and has spent most of that time on cellular routers, data SIMs and the antennas that connect them for business and industrial sites. He writes 4G SIM to explain how the networks and the kit actually behave, in plain English.