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Bluetooth LE, Wi-Fi and 802.15.4

Common radios in home and wearable devices, and how each one trades range, speed and battery life.

Foundation

Bluetooth LE, Wi-Fi and IEEE 802.15.4 at a glance Bluetooth LE splits the 2.4 GHz band into 40 channels, 3 of them for advertising, and has three PHYs. Wi-Fi generation numbers map to IEEE 802.11 letters, and Target Wake Time lets a device sleep between agreed wake times. Zigbee and Thread both sit on the 250 kbit/s IEEE 802.15.4 radio. Bluetooth LE 2.4 GHz band 40 channels, 2 MHz apart 3 primary advertising channels, used for discovery Bluetooth 5.0 added LE 2M and LE Coded LE 1M the original PHY LE 2M higher throughput LE Coded longer range 125 or 500 kbit/s Bluetooth Core 6.0 (2024) added Channel Sounding, which measures the distance between two devices. Wi-Fi Generation names and IEEE standards Wi-Fi 4 802.11n Wi-Fi 5 802.11ac Wi-Fi 6 802.11ax Wi-Fi 7 802.11be Target Wake Time first in HaLow, mainstream in Wi-Fi 6 wake wake wake asleep asleep Wakes to exchange data at times agreed with the access point Wi-Fi HaLow (802.11ah): below 1 GHz, longer range and better wall penetration, lower data rates IEEE 802.15.4 Low rate, low power Zigbee Thread IEEE 802.15.4 radio: 250 kbit/s at 2.4 GHz
Bluetooth LE splits the 2.4 GHz band into 40 channels, Wi-Fi generation numbers map to 802.11 letters, and Zigbee and Thread share the IEEE 802.15.4 radio.

Key points

  1. Bluetooth Low Energy uses the 2.4 GHz band, divided into 40 channels 2 MHz apart; 3 of them are the primary advertising channels used for discovery.1
  2. Bluetooth 5.0 added the LE 2M PHY for higher throughput and the LE Coded PHY (125 or 500 kbit/s) for longer range, alongside the original LE 1M PHY.12
  3. Bluetooth Core 6.0, adopted in 2024, introduced Channel Sounding, which measures the distance between two devices using phase-based ranging and round-trip time.34as of 6 October 2026
  4. Wi-Fi generation names map to IEEE standards: Wi-Fi 4 is 802.11n, Wi-Fi 5 is 802.11ac, Wi-Fi 6 is 802.11ax and Wi-Fi 7 is 802.11be.56
  5. Target Wake Time lets a device agree with the access point when it will next wake to exchange data, so battery-powered clients can sleep longer. It was first defined for Wi-Fi HaLow (802.11ah) and Wi-Fi 6 brought it to mainstream Wi-Fi.78
  6. Wi-Fi HaLow (802.11ah) runs below 1 GHz for longer range and better wall penetration at lower data rates; which sub-GHz frequencies it may use depends on each country's spectrum rules.9810
  7. IEEE 802.15.4 is a low-rate, low-power radio standard; in the 2.4 GHz band it carries 250 kbit/s. Zigbee and Thread are both built on it.111213

Where to go next

Sources

  1. Bluetooth Core Specification · Bluetooth SIG · Standard
  2. Exploring Bluetooth 5: Going the distance · Bluetooth SIG · News
  3. Bluetooth Core 6.0 feature overview · Bluetooth SIG · Standard
  4. Bluetooth SIG introduces true distance awareness · Bluetooth SIG · News
  5. Wi-Fi Alliance introduces Wi-Fi 6 · Wi-Fi Alliance · News
  6. Wi-Fi 7: Advanced connectivity for the next generation · Wi-Fi Alliance · Vendor page
  7. Wi-Fi CERTIFIED 6 · Wi-Fi Alliance · Standard
  8. Wi-Fi CERTIFIED HaLow Technology Overview (Nov 2021) · Wi-Fi Alliance · Reference
  9. Wi-Fi HaLow · Wi-Fi Alliance · Standard
  10. IEEE 802.11ah-2016: Sub 1 GHz License Exempt Operation · IEEE · Standard
  11. IEEE 802.15.4: Low-Rate Wireless Networks · IEEE · Standard
  12. Thread Network Fundamentals (May 2020) · Thread Group · Reference
  13. Matter FAQs · Connectivity Standards Alliance · Vendor page