Reference sheet
Wireless comparison
BLE, WiFi, LoRa, Zigbee: range, rate, power and licence
Wireless comparison
Ranges assume clear line of sight and are the first figure to collapse indoors. The more useful question is what has to exist at the other end: a phone (BLE), a router (Wi-Fi), a gateway (LoRaWAN, Zigbee), another board of the same make (ESP-NOW, NRF24L01+), or a paid subscription (LTE-M). Everything here except LTE-M runs in unlicensed spectrum, but unlicensed still means rules — LoRa's EU duty cycle is the one that catches people. Frequencies and legal power limits are in the Radio bands sheet.
| Technology | Band | Realistic range | Data rate | Power | Topology | Licence & catch |
|---|---|---|---|---|---|---|
| Bluetooth LE (4.2 / 5) | 2.4 GHz ISM | 10–50 m indoors, more on Coded PHY | 1–2 Mbps on air, 20–100 kbps real | 5–15 mA TX, µA asleep | Star; mesh via Bluetooth Mesh | Unlicensed. The connection interval sets throughput, not the PHY rate |
| Bluetooth Classic (BR/EDR) | 2.4 GHz ISM | 10 m (class 2), 100 m (class 1) | 1–2 Mbps real | ~30 mA active, no useful sleep | Piconet, 7 active slaves | Unlicensed. HC-05/06 speak this, and BLE-only hosts cannot see them |
| Wi-Fi 2.4 GHz (b/g/n) | 2.4 GHz ISM | 30–50 m indoors, 100 m+ outside | 72 Mbps on air, 10–20 Mbps on an ESP32 | 100–350 mA in bursts | Star, to an access point | Unlicensed. Leave 500 mA of headroom or the board resets while connecting |
| ESP-NOW | 2.4 GHz ISM | 100–200 m line of sight | 1 Mbps, 250-byte packets | Wi-Fi radio, but sleeps between packets | Peer to peer, 20 paired peers, far fewer encrypted | Unlicensed, Espressif only. No router and no IP, but a 250-byte cap |
| LoRa (SX1276 / SX1262) | 433 / 868 / 915 MHz | 2–5 km urban, 10 km+ rural | 0.3–27 kbps by spreading factor | 120 mA TX at +20 dBm, µA asleep | Point to point, or a LoRaWAN gateway | Duty-cycle limited: 1 % on EU 868 MHz, dwell-time rules in the US |
| Zigbee (802.15.4) | 2.4 GHz ISM | 10–100 m per hop, mesh extends it | 250 kbps on air, far less in use | Routers stay awake, end devices sleep | Mesh: coordinator, routers, end devices | Unlicensed. Needs a coordinator, and it sits on top of the Wi-Fi band |
| NRF24L01+ | 2.4 GHz ISM | 30–100 m, further with PA/LNA | 250 kbps, 1 Mbps or 2 Mbps | ~12 mA TX at 0 dBm, µA asleep | Star, 6 pipes per receiver | No stack and no encryption. Wants 10–100 µF at the module or it drops out |
| LTE-M / NB-IoT | Licensed cellular | Cellular coverage — kilometres | LTE-M 0.3–1 Mbps, NB-IoT 20–100 kbps | µA in PSM, but 0.5–2 A TX peaks | Star, to the operator network | Licensed: a SIM, a data plan, and a module certified for your region |
