Cellular IoT

Australian network context (mid-2026): 2G was switched off years ago (Telstra 2016, Optus 2017, Vodafone 2018) and 3G is now also gone (Vodafone/TPG Jan 2024, Telstra + Optus Oct 2024). Only 4G/5G remain, plus the IoT-specific LTE-M (Cat-M1) and NB-IoT networks. The band that matters most here is Band 28 (700 MHz), which Telstra and Optus lean on heavily for IoT and rural/wide-area coverage. Any module you buy must support B28 — and the GSM/GPRS/EDGE (2G) support these boards advertise is useless in Australia.
Author

Benedict Thekkel

Quick comparison

T-A7670 R2 T-SIM7670G S3 T-SIM7070G
Cellular module A7670 (E / G / SA) SIM7670G SIM7070G
Network tier 4G LTE Cat-1 4G LTE Cat-1 LTE-M / NB-IoT
Throughput 10 ↓ / 5 ↑ Mbps 10 ↓ / 5 ↑ Mbps ~tens–hundreds of kbps
Works in Australia? ✅ only G or SA (not E) ✅ global, incl. B28 ✅ on LTE-M / NB-IoT
Power profile Moderate Moderate Ultra-low (battery)
Camera interface ❌ ✅ [H802] SKU only ❌
GNSS / GPS Optional (pick a “With GPS” SKU) ✅ ✅
MCU ESP32 (WROVER) ESP32-S3 ESP32
List price $32.89 USD (≈ $27 on AliExpress) $36.02 USD $29.01 USD
Best for Cheapest general 4G data / telemetry Camera + frequent telemetry Battery sensor phoning home

Prices are vendor list (USD) as of this writing; expect roughly $45–80 AUD landed after shipping/GST. Add a camera and antennas where the board doesn’t include them.

T-A7670 R2

Marketed as: “Wireless Module ESP32 Chip 4G LTE CAT1 MCU32 Development Board”

A classic ESP32 + A7670 4G LTE Cat-1 board — same data tier as the SIM7670G (10 Mbps down / 5 Mbps up), but the cheapest of the three and built around a regular ESP32 (WROVER) rather than an S3. It bundles the ESP32, A7670 modem, nano-SIM slot, microSD, optional GPS, an 18650 holder, solar charging and battery management on one board. Fine for periodic image uploads and steady telemetry over the network — but note there is no onboard camera interface, so a camera would have to be handled separately. This is the general-purpose “get data to the internet” board, not a camera platform.

⚠️ The variant choice is make-or-break: E / G / SA

The A7670 ships in three regional band variants. They are the same board — only the modem’s LTE bands differ:

Variant Designed for Band 28 (AU)? Verdict for Australia
A7670E Europe / SE Asia / South America ❌ No (tops out at B20) ❌ Do not buy — flaky-to-dead here
A7670G Global (widest coverage) ✅ Yes ✅ Safe choice (LilyGO’s recommended)
A7670SA South America / New Zealand / Australia ✅ Yes ✅ Purpose-built for ANZ

For Brisbane: buy the G or the SA — never the E. GPS is a separate per-SKU option (e.g. T-A7670G R2 With GPS), so pick a “With GPS” variant if you want GNSS.

Hardware gotchas

  • The microSD card uses IO2 as its CS line, which clashes with flashing — you must remove the SD card when uploading a sketch.
  • Battery voltage can’t be read over USB (the BAT ADC only works on battery power); recommended solar input is 4.4–6 V — don’t exceed it.

Buy (variant selector): https://lilygo.cc/products/t-sim-a7670e Docs: https://github.com/Xinyuan-LilyGo/LilyGO-T-A7670X

T-SIM7670G S3

The 4G Cat-1 board with a camera option — the best fit for image frames + frequent telemetry.

The SIM7670G is a 4G LTE Cat-1 modem (up to 10 Mbps down / 5 Mbps up) on the global band set, which includes Band 28 — so it’s a safe choice on Telstra/Optus with no region-variant guesswork. Built on an ESP32-S3, so you also get Wi-Fi + BLE locally alongside the 4G uplink.

Watch the SKU — two variants exist

Feature [H707] [H802] “Standard”
MCU ESP32-S3-WROOM-1 N16R8 (16 MB flash / 8 MB PSRAM) ESP32-S3-WROOM-1 N16R2 (16 MB flash / 2 MB PSRAM)
Camera interface ❌ ✅
QWIIC ❌ ✅
Seamless power switching ❌ ✅
GNSS routing to SoC + PPS ❌ ✅
eSIM pad ❌ ✅

If you want the camera, you must buy the [H802] SKU. The catch: the camera-capable H802 has only 2 MB PSRAM — fine for an OV2640 at VGA/SVGA JPEG, but tight for high-resolution frames (big framebuffers want 8 MB). The 8 MB-PSRAM H707 has no camera header at all.

Buy: https://lilygo.cc/products/t-sim-7670g-s3

T-SIM7070G

The low-power board — right country, wrong tier for camera work.

The SIM7070G is a multi-mode LTE-M (Cat-M1) / NB-IoT module (with a 2G GPRS fallback that’s irrelevant in Australia). LTE-M and NB-IoT do run on Telstra and Optus, so it connects fine here.

The point of this board is power, not speed. Throughput is tiny — designed for a sensor that wakes, sends a small payload (a few readings, a status, a GPS fix), and sleeps for hours or days on a battery. A camera frame would crawl or fail to upload reliably.

  • Choose it for: battery/solar remote sensors, small infrequent payloads, multi-year deployments where power budget dominates.
  • Don’t choose it for: images, video, or frequent/bulky data — use a Cat-1 board instead.

Buy: https://lilygo.cc/products/t-sim7070g

Recommendation

For a camera + frequent-telemetry build: the T-SIM7670G S3 [H802] is the pick — correct Cat-1 tier, global Band 28, and the only one here with a camera interface.

If the camera is handled separately (or you don’t need one): the T-A7670 R2 (G or SA, With GPS) is the cheapest solid 4G Cat-1 board for getting telemetry to the internet — just never buy the E variant.

If the project is really a low-power battery sensor: the T-SIM7070G is the right tool; the Cat-1 boards would waste its power advantage.

Easiest-path alternative to all of the above: the Waveshare ESP32-S3-SIM7670G-4G (same SIM7670G modem, same Cat-1 tier, same Band 28) ships as a near-complete kit — OV2640 camera, LTE + GNSS antennas, and an acrylic case all in the box — and is stocked locally in Australia (~$99 AUD, same-day dispatch). Costs more than the bare LilyGO boards, but saves the offshore shipping wait and the hunt for a camera and antennas.

Source: https://iot-store.com.au/products/esp32-sim7670g-4g-lte-gnss

Don’t forget (applies to any of these)

  • SIM + APN. You need a data-capable nano-SIM and the carrier’s APN set in firmware (e.g. Telstra telstra.internet, ALDI mdata.net.au). A cheap prepaid data SIM on the Telstra or Optus network is fine to start.
  • Data costs. Camera frames + frequent telemetry burn data fast. Keep payloads lean — MQTT over raw HTTP, compress images, batch readings, send only on change.
  • Power. These integrated boards already handle the modem’s ~2 A current spikes (onboard power path + battery management). A bare modem wired to a plain MCU without that is the #1 cause of random resets.
  • Software. Quickest route is the TinyGSM Arduino library (gives you a Client for MQTT/HTTP, and supports A7670 / SIM7670 / SIM7070). The cleaner route is ESP-IDF’s esp_modem component, which brings the modem up as a PPP network interface so the standard TCP/IP stack just works.

Tiers at a glance: NB-IoT / LTE-M (SIM7070G) = sips power, tiny data → battery sensors. 4G Cat-1 (A7670 / SIM7670G) = moderate power, real data → images + telemetry. 4G Cat-4 (SIM7600G) = more power, fast → live video.

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