Not everything wireless is cellular. Most of your data indoors goes over Wi-Fi, and billions of devices talk over Bluetooth, Zigbee, LoRa and others. Operators combine them with the cellular network (Wi-Fi offload, VoWiFi, IoT).
1. Wi-Fi (IEEE 802.11)
| Generation |
Standard |
Year |
Band |
Max channel |
Typical PHY maximum |
Key feature |
| — |
802.11b |
1999 |
2.4 GHz |
22 MHz |
11 Mbit/s |
DSSS |
| — |
802.11a |
1999 |
5 GHz |
20 MHz |
54 Mbit/s |
OFDM |
| — |
802.11g |
2003 |
2.4 GHz |
20 MHz |
54 Mbit/s |
OFDM on 2.4 |
| Wi-Fi 4 |
802.11n |
2009 |
2.4 / 5 GHz |
40 MHz |
600 Mbit/s |
MIMO (up to 4 streams) |
| Wi-Fi 5 |
802.11ac |
2013 |
5 GHz |
160 MHz |
~3.5 Gbit/s |
MU-MIMO (downlink), 256QAM |
| Wi-Fi 6 / 6E |
802.11ax |
2019 / 2020 |
2.4, 5 (+ 6 GHz in 6E) |
160 MHz |
~9.6 Gbit/s |
OFDMA, uplink MU-MIMO, TWT (target wake time), BSS colouring, 1024QAM |
| Wi-Fi 7 |
802.11be |
2024 |
2.4, 5, 6 GHz |
320 MHz |
~46 Gbit/s |
MLO (multi-link operation), 4096QAM, multi-RU |
| Wi-Fi 8 (in development) |
802.11bn |
~2028 |
|
|
|
Reliability, ultra-high reliability (UHR) |
Related: 802.11ah (Wi-Fi HaLow) sub-GHz for IoT; 802.11ad/ay (WiGig) 60 GHz; 802.11p vehicle; 802.11s mesh; 802.11r/k/v fast roaming and steering; 802.11ba wake-up radio; 802.11bb Li-Fi.
Key Wi-Fi concepts
| Term |
Meaning |
| SSID / BSSID / ESS |
Network name / the access point's MAC address / network of several APs |
| AP / controller / mesh node |
Access Point / central management / wireless-backhauled AP |
| CSMA/CA |
Listen before you talk; Wi-Fi is contention-based (unlike scheduled LTE) |
| Channels in 2.4 GHz |
Only 3 non-overlapping (1, 6, 11 in US; 1, 5, 9, 13 in EU with 20 MHz) |
| DFS |
Dynamic Frequency Selection — avoids radar in some 5 GHz channels |
| Roaming |
Moving between APs; 802.11r speeds up keys |
| WPA2 / WPA3 |
Security: PSK (home) or 802.1X/EAP (enterprise). WPA3-SAE protects against offline password guessing; OWE gives encryption on open networks |
| 802.1X / EAP / RADIUS |
Enterprise authentication; EAP-SIM / EAP-AKA = login with your SIM |
| Hotspot 2.0 / Passpoint |
Automatic secure connection to operator Wi-Fi |
| Captive portal |
Login page of public Wi-Fi |
| Wi-Fi offload / ANDSF |
Moving traffic from cellular to Wi-Fi |
| VoWiFi (WFC) |
IMS voice/SMS over Wi-Fi through an ePDG tunnel (Module 9) |
| LTE-U / LAA / NR-U |
Cellular in the unlicensed 5/6 GHz bands |
| WLAN controller (WLC), CAPWAP, cloud APs |
Centralised management |
| Wi-Fi Alliance |
Certification body (Wi-Fi CERTIFIED) |
| Wi-Fi sensing (802.11bf) |
Using Wi-Fi to detect motion |
2. Bluetooth
| Version / feature |
Notes |
| Classic (BR/EDR) |
1–3 Mbit/s, audio streaming, 79 channels at 2.4 GHz, frequency hopping |
| Bluetooth Low Energy (BLE, 4.0+) |
Low-power, 40 channels, tiny data bursts: sensors, wearables, beacons |
| 5.0 – 5.4 |
2 Mbit/s, long range (Coded PHY), advertising extensions, direction finding (AoA/AoD) in 5.1, LE Audio (LC3 codec, Auracast broadcast) |
| Mesh |
Many-to-many networking for lighting |
| Profiles |
A2DP (audio), HFP (hands-free), HID (keyboards), GATT (BLE data), PAN, ATT/GATT |
| Range |
~10 m class 2, up to 100+ m class 1/long-range BLE |
| Pairing |
LE Secure Connections (ECDH) |
| Security issues |
BlueBorne, KNOB, BIAS, tracking by static addresses (hence random private addresses) |
3. NFC, RFID, UWB
| Tech |
Frequency |
Range |
Use |
| NFC |
13.56 MHz |
≤ 4–10 cm |
Contactless payment, tickets, pairing; reader/writer, card emulation, peer-to-peer |
| RFID LF |
125–134 kHz |
cm |
Animal tags, door access |
| RFID HF |
13.56 MHz |
cm–1 m |
Library, ticketing |
| RFID UHF |
860–960 MHz (EU 865–868) |
up to ~10 m |
Logistics, retail inventory (EPC Gen2) |
| UWB |
3.1–10.6 GHz, very wide pulses |
up to ~50 m, cm-level accuracy |
Digital car keys, AirTag-style finding, indoor positioning (IEEE 802.15.4z) |
4. Personal and home automation networks
| Tech |
Standard |
Band |
Notes |
| Zigbee |
IEEE 802.15.4 |
2.4 GHz (also 868/915) |
Mesh, low power, smart lighting |
| Thread |
802.15.4 + 6LoWPAN |
2.4 GHz |
IPv6 mesh for smart homes |
| Z-Wave |
proprietary |
sub-GHz (868.4 MHz EU) |
Home automation |
| Matter |
CSA standard |
over Wi-Fi, Thread, Ethernet |
Interoperability layer for smart home |
| 6LoWPAN |
IETF |
|
IPv6 over low-power links |
| ANT+ |
|
2.4 GHz |
Sports sensors |
5. LPWAN — Low Power Wide Area Networks (long range, tiny data)
| Tech |
Band |
Range |
Data rate |
Notes |
| NB-IoT |
licensed LTE spectrum, 180 kHz |
km, deep indoor |
~30–60 kbit/s |
Cellular, operator-provided; 3GPP |
| LTE-M (Cat-M1) |
licensed LTE |
km |
~1 Mbit/s |
Mobility, voice |
| LoRa / LoRaWAN |
unlicensed sub-GHz (EU 863–870 MHz, 868 MHz), CSS modulation |
2–15 km |
0.3–50 kbit/s |
Own gateways; community networks (The Things Network); LoRa Alliance; classes A/B/C |
| Sigfox |
868 MHz ultra-narrowband |
10–40 km |
≤ 100 bit/s uplink (12 bytes/msg) |
Proprietary; company went bankrupt 2022 and was reorganised (UnaBiz) |
| Wi-SUN |
sub-GHz mesh |
|
up to 300 kbit/s |
Smart utility meters |
| Mioty, DASH7, Weightless |
|
|
|
Other niche LPWAN |
| Satellite IoT |
|
|
|
NB-NTN, Sateliot, Swarm |
Choosing: short range + high rate → Wi-Fi; short range + low power → BLE; wide area + tiny data + cheap + you own gateways → LoRaWAN; wide area + operator SLA + mobility → LTE-M/NB-IoT.
| Term |
Meaning |
| MQTT |
Lightweight publish/subscribe messaging (TCP, port 1883/8883) |
| CoAP |
Constrained Application Protocol — "HTTP for tiny devices" over UDP |
| LwM2M |
OMA Lightweight M2M: device management |
| OneM2M |
Standard IoT service layer |
| Edge gateway |
Collects local device data and sends it to the cloud |
| Digital twin |
Virtual model of a physical asset |
| OTA / FOTA |
Over-the-air (firmware) updates |
| CMP / SIM management |
Connectivity management platform for IoT SIMs |
| TinyML / edge AI |
Machine learning on microcontrollers |
7. Positioning without GNSS
Cell ID, E-CID, OTDOA, UTDOA, Multi-RTT, AoA/AoD, Wi-Fi RTT (802.11mc), BLE direction finding, UWB, Wi-Fi fingerprinting (databases of SSIDs). 5G positioning (Rel-16/17) targets meter to sub-meter accuracy.
Remember this: every wireless technology is a trade-off between range, data rate, power and cost. Cellular wins on coverage and mobility, Wi-Fi on cheap local capacity, Bluetooth on device-to-device, LoRa on cheap sensors over kilometres.