LTE Class & Speed

Cat-4 (≈150/50 Mbps) suits cameras and gateways; Cat-1 (≈10/5 Mbps) covers most telemetry; LTE-M/NB-IoT (kbps) is for tiny, infrequent battery messages. Faster isn’t always better — it costs more power and money.

Frequency Bands & Region

The letter suffix is the region: G = global, A = Americas, E = Europe/Asia, SA = South America/ANZ. Match the module’s bands to your carrier, or buy the global “G” version to be safe.

Host Interface & Form Factor

HATs stack on a Raspberry Pi, shields on an Arduino, all-in-one boards bundle an ESP32, and mini-PCIe cards slot into routers/SBCs. Control is via UART (AT commands) or USB. Pick the shape that fits your host.

Built-in GNSS / GPS

Most modules here add GPS/GLONASS/BeiDou positioning on a second antenna — perfect for trackers and asset monitoring. It saves you a separate GPS module, but usually can’t run at the same instant as the cellular radio.

Power & Antenna

Transmit bursts can spike to 2 A on Cat-4, so give the module a solid 3.4–5 V supply and good decoupling. For battery projects, LTE-M/NB-IoT parts with PSM/eDRX sleep (microamps) are the only sensible choice.

When your project sends a few readings a day and has to live on a battery for months, speed is the enemy — you want the tiny sleep currents of LTE-M and NB-IoT. The Waveshare SIM7080G HAT delivers exactly that: dual-mode Cat-M/NB-IoT with global bands, GNSS positioning, and a power-saving PSM sleep down around 3.2 µA. An onboard USB port makes AT-command testing painless, and broken-out UART pins let you drive it from an Arduino or STM32 as easily as a Raspberry Pi.

For the Arduino crowd, the Botletics SIM7000G shield is the classic answer. It stacks straight onto an Uno/Mega/Leonardo (and wires easily to ESP8266, ESP32 or a Pi), runs the low-power SIM7000-series Cat-M1/NB-IoT modem with multi-GNSS, and adds an onboard LiPo charger so a solar cell and battery make it fully off-grid. Draw drops to about 7.4 µA in its lowest state, and the open-source library plus superb wiki make it one of the most beginner-friendly cellular boards ever made. Note the global SIM7000G is the current kit — the old region-locked SIM7000A has been discontinued.

The LILYGO T-A7670G R2 is the value champion for connected ESP32 projects. Its A7670G is an LTE Cat-1 modem — around 10 Mbps down, 5 Mbps up, plenty for SMS, MQTT and telemetry — with 2G GSM/GPRS fallback so it still connects in areas without LTE. The “G with GPS” version adds a dedicated L76K GPS receiver, and the board carries an ESP32-WROVER, microSD slot and 18650 holder. It’s the natural pick for a low-cost GPS tracker or remote logger that you don’t want to overspend on.

The LILYGO T-SIM7670G-S3 is the modern, compact take on an all-in-one Cat-1 board. It pairs the newer ESP32-S3 (240 MHz, 16 MB flash, 8 MB PSRAM, Wi-Fi + BT5) with SIMCom’s SIM7670G global LTE Cat-1 modem and GNSS. Because SIM7670G is LTE-only (no 2G), it’s clean and current-friendly, and the extra ESP32-S3 horsepower and RAM leave lots of headroom for a display, camera or heavier firmware. A microSD slot and battery support round out a tidy platform for trackers and remote nodes.

When you’re building a router, an SBC gateway or an industrial box rather than a bare-MCU gadget, the Quectel EG25-G is the professional’s module. It’s a global LTE Cat-4 card (150/50 Mbps) in standard mini-PCIe form factor with USB 2.0, multi-constellation GNSS, wide carrier certifications and an extended −35 °C to +75 °C operating range. Drop it into a Raspberry Pi base HAT, an OpenWrt router or an x86 gateway and you get carrier-grade connectivity with the reliability Quectel is known for. It needs a carrier board and antennas — it’s a module, not a plug-and-play kit.

On a Raspberry Pi, need speed?

The Waveshare SIM7600G-H HAT gives global Cat-4 (150/50) plus GNSS and stacks straight onto the Pi.

Want ESP32 + 4G in one board?

The LILYGO T-SIM7600G-H bundles ESP32, Cat-4, GPS, 18650 and solar charging — no separate host needed.

Battery sensor for months?

Go low-power with the Waveshare SIM7080G HAT or Botletics SIM7000G — LTE-M/NB-IoT with microamp sleep.

Learning on an Arduino Uno?

The Botletics SIM7000G shield plugs in directly and has the best beginner docs and library in the category.

Cheap GPS tracker?

The LILYGO T-A7670G R2 (GPS) is Cat-1 with 2G fallback, a dedicated GPS chip and an ESP32 for the least money.

Building a router or gateway?

The Quectel EG25-G Mini PCIe drops into base HATs and routers for carrier-certified, always-on Cat-4.

What’s the difference between LTE Cat-4, Cat-1 and LTE-M / NB-IoT?

They trade speed against cost and power. Cat-4 (SIM7600, EG25) does up to 150 Mbps — use it for cameras, gateways and anything bandwidth-hungry. Cat-1 (A7670, SIM7670) does around 10 Mbps at lower cost and power, which is plenty for SMS, MQTT and most telemetry. LTE-M and NB-IoT (SIM7000, SIM7080) run at kbps but sleep at microamps, so they’re built for battery sensors that send a little data occasionally over many months or years.

Will these work in my country and on my carrier?

Only if the module’s frequency bands match your network. Buy a global “G” variant (SIM7600G-H, EG25-G, A7670G, SIM7670G) unless you’ve checked your carrier’s exact LTE bands. Also remember many networks are shutting down 2G/3G, so don’t rely on GSM fallback long-term — and LTE-M/NB-IoT only work where the operator has actually deployed them, which is still patchy in some regions.

Do I need a special SIM card?

You need a data-capable SIM. A cheap IoT/M2M plan (Hologram, Twilio, 1NCE, or a data plan from a normal carrier) is ideal. For LTE-M/NB-IoT the SIM and plan must specifically support those technologies. Note the SIM voltage too — some boards (like the SIM7080G HAT) accept 1.8 V SIMs only. A voice-only SIM won’t do data, and cellular boards generally need a full data profile, not a locked handset SIM.

How do I actually control a 4G module from my microcontroller?

You send AT commands over UART (or USB) — text commands like AT+CPIN? to check the SIM and AT+CSQ to read signal strength. In practice you use a library so you don’t hand-write every command: TinyGSM is the go-to for Arduino/ESP32 across SIM7600/A7670/SIM7000, Botletics ship their own SIM7000 library, and Waveshare provide Pi/Arduino/STM32 examples. Start with the vendor’s sample sketch, confirm the module answers AT with OK, then build up.

Can these modules make phone calls?

Most do data and SMS but not voice. Voice needs an audio codec and the right module variant — some SIM7600 boards offer an “audio decoding” option, but the low-power SIM7000/SIM7080 and the Cat-1 SIM7670 are data-only. If your project needs to place or receive calls, confirm the specific variant lists voice/audio support before buying; for most IoT work, SMS and data are all you need anyway.