Connectivity 10 min read

"4G" is a family, not one thing. Here is which member your device should be.

The same network that streams video to a router also carries eight-byte tank readings — through entirely different device categories with different speeds, power budgets, module prices and, crucially, different levels of South African network support. The datasheet line that matters is the one most buyers never read: Cat-what?

By Frank Guo · Technology & Product Leadership, addanode

TL;DR — LTE devices come in categories, and the category decides everything. Cat-4 (150 Mbps) is the router and gateway class — right for an edge gateway aggregating a site, wrong for a battery sensor. Cat-1 and its single-antenna sibling Cat-1bis (10 Mbps down) are the telemetry workhorses: cheap modules, modest power, and — the decisive fact for South Africa — they run on every existing LTE network with no special carrier features. Cat-M1 (LTE-M) and NB-IoT are the true low-power categories, but each requires the carrier to have deployed specific network support: LTE-M has no committed South African deployment, and NB-IoT is a single-carrier story. Practical SA rule: gateways on Cat-4, telemetry nodes on Cat-1/Cat-1bis, battery-for-years sensors on LoRaWAN — and treat any quote built on Cat-M1 hardware as a specification error until proven otherwise.

Why the category line on the datasheet matters

When a proposal says a device "supports 4G", it has told you almost nothing. LTE was designed with device categories — profiles that trade speed against cost, power and complexity — so that a CCTV router and a water-meter radio can share one network without sharing one bill of materials. The category determines the module price (a spread of several times between Cat-4 and Cat-1bis), the antenna count, the power draw that sets your solar and battery sizing, and whether the device works on South African networks at all. Two devices with identical spec-sheet marketing can differ in exactly the ways a remote site discovers six months in.

The family, one table

	Cat-4	Cat-1	Cat-1bis	Cat-M1 (LTE-M)	NB-IoT (Cat-NB)
Peak speed (DL/UL)	150 / 50 Mbps	10 / 5 Mbps	10 / 5 Mbps	~0.3–1 Mbps	Tens of kbps
Bandwidth used	20 MHz	20 MHz	20 MHz	1.4 MHz	200 kHz
Antennas	2	2	1 — smaller, cheaper devices	1	1
Deep-sleep features (PSM/eDRX)	No	No	No	Yes	Yes
Mobility / handover	Full	Full	Full	Yes	Poor — fixed devices only
Module cost tier	Highest	Low	Lowest of the LTE set	Low	Lowest
Needs special carrier deployment?	No — any LTE network	No — any LTE network	No — any LTE network	Yes	Yes
South Africa reality (2026)	Works everywhere	Works everywhere	Works everywhere	No committed deployment	One carrier, verify per site

The South African twist: the "IoT categories" are the ones you mostly can't use

Globally, Cat-M1 and NB-IoT were designed as the low-power IoT endgame — deep sleep modes, extended coverage, minimal modules. But both need the mobile operator to deploy and maintain specific network features, and that is where South Africa diverges from the international datasheet: LTE-M has no committed local deployment, and NB-IoT remains a single-carrier network to be verified site by site. Meanwhile Cat-1 and Cat-1bis need nothing special at all — they are ordinary LTE devices, attached to networks that already cover the country, on modules that now undercut what Cat-M1 hardware costs in practice. This is why international reference designs arrive here specifying Cat-M1 and have to be re-specified: the elegant global answer is the wrong local one. (The same buying rule applies downward: since new 2G/3G-only device activations were barred from the end of 2024, the legacy fallback is closed too — details in our network comparison.)

The gap Cat-M1 was meant to fill — battery-powered sensors that sleep for years — does not go unfilled in South Africa. It is exactly the role LoRaWAN plays in our deployments: coverage you own, no carrier feature dependency, and battery life the cellular categories only approach in their deep-sleep modes.

Which category for which device — the scenario map

Device / scenario	Right category	Why
Edge gateway aggregating a site (OEE data, many sensors, dashboards)	Cat-4	Backhaul bandwidth for a whole site; mains/solar powered anyway, so the power cost of speed is irrelevant
CCTV / video backhaul	Cat-4 (or better)	Sustained upload is the constraint; no lower category carries video
Standalone telemetry node (genset, borehole with solar, tank farm)	Cat-1 / Cat-1bis	Kilobyte payloads need no bandwidth; cheapest modules that work on every SA network today
Vehicle trackers & mobile assets	Cat-1 / Cat-1bis	Full handover between towers at speed; NB-IoT's weak mobility rules it out for anything that moves
Compact single-antenna product designs	Cat-1bis	One antenna shrinks the enclosure and the BOM; the slight coverage-margin loss is acceptable at good signal sites
Battery-only sensor, years of life, fixed site	LoRaWAN (not cellular)	The category built for this (Cat-M1) is not deployed here; LoRaWAN fills the role with coverage you own
Deep-indoor fixed meter, no power, no LoRaWAN option	NB-IoT — verified per site	The one niche where its penetration genuinely wins; single-carrier dependency is the price, so verify before standardising
International product roaming many countries	Cat-M1 + Cat-1 fallback	LTE-M is real in North America/Europe; the fallback is what keeps the device alive in markets like SA

What this means in our own hardware choices

This taxonomy is not academic for us — it is why our bill of materials looks the way it does. When we say a deployment runs on "4G", concretely: site gateways are Cat-4, because they carry a whole site's buffered data and run on mains or solar; standalone telemetry nodes are Cat-1 or Cat-1bis, because a few kilobytes an hour needs the cheapest module that attaches to any tower in the country; and battery-for-years sensing goes to LoRaWAN, not to a cellular category South African networks do not support. Every one of those devices buffers locally and rides out load shedding — the category choice sets the link budget, the architecture sets the resilience.

FAQ

LTE categories — common questions

What is the difference between LTE Cat-1 and Cat-4?

Speed and cost, in opposite directions: Cat-4 reaches 150 Mbps down and suits routers, gateways and video; Cat-1 reaches 10 Mbps on a much cheaper, lower-power module and suits telemetry, trackers and machines that send kilobytes. They attach to the same LTE networks — the category changes the device, not the coverage. For sensor data, paying for Cat-4 buys nothing.

What is LTE Cat-1bis?

Cat-1 with a single antenna instead of two. Same 10/5 Mbps profile, smaller and cheaper to build into a device, at the cost of a little receive-path margin — acceptable at reasonable signal sites, worth respecting at marginal ones. It has become the default module choice for new IoT telemetry designs, and like Cat-1 it needs no special carrier support.

Can I use LTE Cat-M1 (LTE-M) devices in South Africa?

Not as your primary plan: South African operators have no committed LTE-M deployment, so a Cat-M1-only device has no local network to attach to. International designs specifying Cat-M1 must be re-specified — usually to Cat-1/Cat-1bis, or to LoRaWAN when the point of choosing M1 was battery life. Multi-mode modules with Cat-1 fallback are the safe form for products that also ship to LTE-M markets.

Why not use NB-IoT for battery-powered sensors here?

Because its two dependencies bite locally: it needs carrier deployment (a single-network story in South Africa, to be verified per site) and it handles mobility poorly. Where it genuinely wins — deep-indoor, fixed, low-rate points with no LoRaWAN option — it remains worth testing. For most battery-sensing in our deployments, LoRaWAN delivers the power profile without the carrier dependency.

Does the category affect SIM and data costs?

Indirectly. Data pricing follows the plan, not the category — but the category shapes consumption: a Cat-4 gateway shipping a site's aggregated data uses megabytes where a Cat-1 node uses kilobytes, and duty-cycled telemetry on small payloads makes the airtime line almost invisible. The bigger commercial difference is module cost and power system sizing, which the category sets directly.

What should I check on a device datasheet before buying?

Four lines: the LTE category (and whether it matches the job in the scenario table above); the supported bands (must include the SA carriers' LTE bands); whether the device falls back to 2G (worthless here going forward — new 2G/3G-only activations ended in 2024); and ICASA type approval. A device that fails any of the four is a stranded asset with a datasheet.

Primary sources

3GPP — NB-IoT and LTE-M technology overview (the standards body's own description of the low-power categories)
Telit — Cat 1 vs Cat 1bis (the single-antenna trade-off from a module maker)
IoT For All — the true speed of cellular IoT (real-world category throughput versus datasheet peaks)

Category specifications are 3GPP-defined and stable; South African network-support statements reflect September 2026 and are refreshed with our network comparison guide.

Specify the category before you sign for the hardware.

Tell us what the device has to do and where it will live. We will spec the right category — or tell you the job belongs on LoRaWAN.

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